Bio-remediation of Oil Spills using Microbes Essay

Bio-remediation of Oil Spills using Microbes - Essay Example Apart from the above, people illegally may dump the pollutants such as the crude oil into the sea. Moreover, terrorists may also cause the oil spills just to destroy the country’s resources. The major victims of the oil spills occurring in the sea would be the aquatic animals and other marine living organisms which include plants under the sea. Thus, cleaning up and recovering from the oil spill are a major tasks and it is mainly based on the factors such as the nature of the oil that is being spilled, the quantity or the amount and the nature of the area being affected. There are different methods for cleaning up the oil spills which ensemble chemical treatment and Bioremediation. Bioremediation is the process of using the microorganisms to break down and remove the pollutants. â€Å"Bioremediation usually involves the use of biological agents to detoxify a contaminated environment† (Thangarajan et al., 2011). Thus, the noxious wastes of the oil spill can be effectivel y treated using microorganisms isolated and selected from the oil-contaminated environments to biodegrade the hydrocarbons in oil spill are a very promising technique for treatment of oil spills. This paper will feature the function of certain species of bacteria such as Pseudomonas aeruginosa and Bacillus subtilis and their role in Bio-remediation. Biodegradation by natural population of microorganisms can be considered as one of the primary mechanism by which the oil spills which are rich in petroleum hydrocarbons can be eradicated from the environment. The major success of the oil spills bioremediation mainly depends on the nature of the hydrocarbons and one’s ability to maintain and establish the conditions that favors the growth of the microorganisms in the particular contaminated environment. Therefore, the physical and the chemical characteristic of the oil and the oil spill area are the vital determinants in the bioremediation process. Thus, bioremediation encompasses the accelerated biodegradation in a natural way. Bioremediation techniques can be carried out in two different ways namely the in-situ or ex-situ methods. â€Å"In in-situ processes, the biological remediation is conducted at the contaminated site, whereas in ex-situ processes, the contaminated medium is extracted and processed off-site purification facilities.† (Rezende et al, n.d). Thus, bioremediation involves the processes of biostimulation and bioaugmentation. The Phenomenon of biostimulation comprises of addition of nutrients such as nitrogen, potassium and phosphorous and thereby enhancing the growth of the microorganisms through adjusting the environmental conditions such as the temperature, moisture and aeration etc. Thus, most of the bacterial species such as Pseudomonas, Bacillus and Cornybacterium are able to degrade the contaminants effectively under favorable environmental conditions and enriched nutrient supply. (Salami & Elum, 2008). On the other hand, the ot her phenomenon known as the bioaugmentaion where the microorganisms are able to degrade the specific oil spill contaminants namely the hydrocarbons are also being implemented. Therefore, bioremediation can be clearly understood as the phenomenon that exploits the microbial diversity and their metabolic versatility to convert noxious chemical oil spill contami

Lifestyle of blackfoot Essay Example | Topics and Well Written Essays - 1250 words

Lifestyle of blackfoot - Essay Example Buffalo hunting is their major hunting activity. â€Å"The Blackfoot Indian tribe displayed agility in hunting buffalo that outranked other tribes. Their nomadic lifestyle was aided by dogs and later horses. They seldom fought over land but were great warriors in their own right† (Blackfoot Indian Tribe). This paper analyses different aspects of Blackfoot’s life styles. Because of huge diversity in culture, the life styles of Blackfoot (Also known as Blackfeet) people are different. Different languages, clothing, hunting methods, worshipping methods, food habits and hobbies are prevailing among the Blackfoot community because of the differences in their ethnicity. â€Å"Mi'kmaq, Cree, Ojibwa, Arapaho, Shawnee, Fox, Algonquin† etc are some of the major languages in the Blackfoot community (Tribal Lifestyle, Gender Roles, Elders). â€Å"The members of a Blackfoot Indian tribe spoke a language called Pikunii. This is language was lyrical and musical to the ear with complex word formations. The language was learned by word of mouth and there was no written language† (Blackfoot Indian Tribe). ... In other words, inter-tribal marital relationship is also possible among some of the tribal groups of the Blackfoot community. â€Å"There are three main clans in the Blackfoot community: The Kainai (Many Leaders, also called the Blood); The Piikani (Amsskaapipiikani in Montana and Apatohsipiikani in southern Alberta also called the Peigan ); The Siksika (Blackfoot, also called northern Blackfoot)† (Tribal Lifestyle, Gender Roles, Elders). Even though, these clans have lot of differences in their life styles, the elements of a common culture can be seen in the life styles of these people. â€Å"Each tribe in Blackfoot community consisted of a number of hunting bands, which were the primary political units of the tribe† (Hanes & Pifer). Each hunting band may have two leaders; one for leading the group for hunting activities and the other for leading the group in other social and political activities. The hunting leader would be an expert hunter whereas the other leader w ould be a person with immense capabilities in solving the social problems. In case of any disputes occur, the final word comes from either the hunting leader or the civilian leader. During ancient period, arrows and lances were the major war weapons of the Blackfoot community. Blackfoot community had no hesitation in engaging in war with other tribal groups. They were clever warriors and their fighting spirit and better war strategy helped them to expand their territories. The Blackfoot or Siksikas were one of the most famous of the northern tribes, largely due to the fact that they were among the first to encounter and form relationships with European fur traders. Through this contact, the people of the Siksika nation became familiar with the objects, inventions and animals brought by these

Single Stage to Orbit (SSTO) Propulsion System

Single Stage to Orbit (SSTO) Propulsion System This paper discusses the relevant selection criteria for a single stage to orbit (SSTO) propulsion system and then reviews the characteristics of the typical engine types proposed for this role against these criteria. The engine types considered include Hydrogen/Oxygen (H2/O2) rockets, Scramjets, Turbojets, Turborockets and Liquid Air Cycle Engines. In the authors opinion none of the above engines are able to meet all the necessary criteria for an SSTO propulsion system simultaneously. However by selecting appropriate features from each it is possible to synthesise a new class of engines which are specifically optimised for the SSTO role. The resulting engines employ precooling of the airstream and a high internal pressure ratio to enable a relatively conventional high pressure rocket combustion chamber to be utilised in both airbreathing and rocket modes. This results in a significant mass saving with installation advantages which by careful design of the cycle thermodynamics enable s the full potential of airbreathing to be realised. The SABRE engine which powers the SKYLON launch vehicle is an example of one of these so called Precooled hybrid airbreathing rocket engines and the conceptual reasoning which leads to its main design parameters are described in the paper. Keywords: Reusable launchers, SABRE, SKYLON, SSTO 1.Introduction Several organisations world-wide are studying the technical and commercial feasibility of reusable SSTO launchers. This new class of vehicles appear to offer the tantalising prospect of greatly reduced recurring costs and increased reliability compared to existing expendable vehicles. However achieving this breakthrough is a difficult task since the attainment of orbital velocity in a re-entry capable single stage demands extraordinary propulsive performance. Most studies to date have focused on high pressure hydrogen/oxygen (H2/O2) rocket engines for the primary propulsion of such vehicles. However it is the authors opinion that despite recent advances in materials technology such an approach is not destined to succeed, due to the relatively low specific impulse of this type of propulsion. Airbreathing engines offer a possible route forward with their intrinsically higher specific impulse. However their low thrust/weight ratio, limited Mach number range and high dynamic pressure trajectory have in the past cancelled any theoretical advantage. By design review of the relevant characteristics of both rockets and airbreathing engines this paper sets out the rationale for the selection of deeply precooled hybrid airbreathing rocket engines for the main propulsion system of SSTO launchers as exemplified by the SKYLON vehicle [1]. 2. Propulsion Candidates This paper will only consider those engine types which would result in politically and environmentally acceptable vehicles. Therefore engines employing nuclear reactions (eg: onboard fission reactors or external nuclear pulse) and chemical engines with toxic exhausts (eg: fluorine/oxygen) will be excluded. The candidate engines can be split into two broad groups, namely pure rockets and engines with an airbreathing component. Since none of the airbreathers are capable of accelerating an SSTO vehicle all the way to orbital velocity, a practical vehicle will always have an onboard rocket engine to complete the ascent. Therefore the use of airbreathing has always been proposed within the context of improving the specific impulse of pure rocket propulsion during the initial lower Mach portion of the trajectory. Airbreathing engines have a much lower thrust/ weight ratio than rocket engines (à ¢Ã¢â‚¬ °Ã‹â€ 10%) which tends to offset the advantage of reduced fuel consumption. Therefore vehicles with airbreathing engines invariably have wings and employ a lifting trajectory in order to reduce the installed thrust requirement and hence the airbreathing engine mass penalty. The combination of wings and airbreathing engines then demands a low flat trajectory (compared to a ballistic rocket trajectory) in order to maximise the installed performance (i.e. (thrust-drag)/fuel flow). This high dynamic pressure trajectory gives rise to one of the drawbacks of an airbreathing approach since the airframe heating and loading are increased during the ascent which ultimately reflects in increased structure mass. However the absolute level of mass growth depends on the relative severity of the ascent as compared with reentry which in turn is mostly dependant on the type of airbreathing engine selected. An a dditional drawback to the low trajectory is increased drag losses particularly since the vehicle loiters longer in the lower atmosphere due to the lower acceleration, offset to some extent by the much reduced gravity loss during the rocket powered ascent. Importantly however, the addition of a set of wings brings more than just performance advantages to airbreathing vehicles. They also give considerably increased abort capability since a properly configured vehicle can remain in stable flight with up to half of its propulsion systems shutdown. Also during reentry the presence of wings reduces the ballistic coefficient thereby reducing the heating and hence thermal protection system mass, whilst simultaneously improving the vehicle lift/drag ratio permitting greater crossrange. The suitability of the following engines to the SSTO launcher role will be discussed since these are representative of the main types presently under study within various organisations world-wide: Liquid Hydrogen/Oxygen rockets Ramjets and Scramjets Turbojets/Turborockets and variants Liquid Air Cycle Engines (LACE) and Air Collection Engines (ACE) Precooled hybrid airbreathing rocket engines (RB545/SABRE) 3.Selection Criteria The selection of an optimum propulsion system involves an assessment of a number of interdependant factors which are listed below. The relative importance of these factors depends on the severity of the mission and the vehicle characteristics. Engine performance Useable Mach number and altitude range. Installed specific impulse. Installed thrust/weight. Performance sensitivity to component level efficiencies. Engine/Airframe integration Effect on airframe layout (Cg/Cp pitch trim structural efficiency). Effect of required engine trajectory (Q and heating) on airframe technology/materials. Technology level Materials/structures/aerothermodynamic and manufacturing technology. Development cost Engine scale and technology level. Complexity and power demand of ground test facilities. Necessity of an X plane research project to precede the main development program. 4.Hydrogen/Oxygen Rocket Engines Hydrogen/oxygen rocket engines achieve a very high thrust/weight ratio (60-80) but relatively low specific impulse (450-475 secs in vacuum) compared with conventional airbreathing engines. Due to the relatively large à ¢Ã‹â€ Ã¢â‚¬  V needed to reach low earth orbit (approx 9 km/s including gravity and drag losses) in relation to the engine exhaust velocity, SSTO rocket vehicles are characterised by very high mass ratios and low payload fractions. The H2/O2 propellant combination is invariably chosen for SSTO rockets due to its higher performance than other alternatives despite the structural penalties of employing a very low density cryogenic fuel. In order to maximise the specific impulse, high area ratio nozzles are required which inevitably leads to a high chamber pressure cycle in order to give a compact installation and reduce back pressure losses at low altitude. The need to minimise back pressure losses normally results in the selection of some form of altitude compensating nozzle since conventional bell nozzles have high divergence and overexpansion losses when running in a separated condition. The high thrust/weight and low specific impulse of H2/O2 rocket engines favours vertical takeoff wingless vehicles since the wing mass and drag penalty of a lifting trajectory results in a smaller payload than a steep ballistic climb out of the atmosphere. The ascent trajectory is therefore extremely benign (in terms of dynamic pressure and heating) with vehicle material selection determined by re-entry. Relative to airbreathing vehicles a pure rocket vehicle has a higher density (gross take off weight/volume) due to the reduced hydrogen consumption which has a favourable effect on the tankage and thermal protection system mass. In their favour rocket engines represent broadly known (current) technology, are ground testable in simple facilities, functional throughout the whole Mach number range and physically very compact resulting in good engine/airframe integration. Abort capability for an SSTO rocket vehicle would be achieved by arranging a high takeoff thrust/weight ratio (eg: 1.5) and a large number of engines (eg: 10) to permit shutdown of at least two whilst retaining overall vehicle control. From an operational standpoint SSTO rockets will be relatively noisy since the high takeoff mass and thrust/weight ratio results in an installed thrust level up to 10 times higher than a well designed airbreather. Reentry should be relatively straightforward providing the vehicle reenters base first with active cooling of the engine nozzles and the vehicle base. However the maximum lift/drag ratio in this attitude is relatively low (approx 0.25) limiting the maximum achievable crossrange to around 250 km. Having reached a low altitude some of the main engines would be restarted to control the subsonic descent before finally effecting a tailfirst landing on legs. Low crossrange is not a particular problem providing the vehicle operator has adequate time to wait for the orbital plane to cross the landing site. However in the case of a military or commercial operator this could pose a serious operational restriction and is consequently considered to be an undesirable characteristic for a new launch vehicle. In an attempt to increase the crossrange capability some designs attempt nosefirst re-entry of a blunt cone shaped vehicle or alternatively a blended wing/body configuration. This approach potentially increases the lift/drag ratio by reducing the fuselage wave drag and/or increasing the aerodynamic lift generation. However the drawback to this approach is that the nosefirst attitude is aerodynamically unstable since the aft mounted engine package pulls the empty center of gravity a considerable distance behind the hypersonic center of pressure. The resulting pitching moment is difficult to trim without adding nose ballast or large control surfaces projecting from the vehicle base. It is expected that the additional mass of these components is likely to erode the small payload capability of this engine/vehicle combination to the point where it is no longer feasible. Recent advances in materials technology (eg: fibre reinforced plastics and ceramics) have made a big impact on the feasibility of these vehicles. However the payload fraction is still very small at around 1-2% for an Equatorial low Earth orbit falling to as low as 0.25% for a Polar orbit. The low payload fraction is generally perceived to be the main disadvantage of this engine/vehicle combination and has historically prevented the development of such vehicles, since it is felt that a small degree of optimism in the preliminary mass estimates may be concealing the fact that the real payload fraction is negative. One possible route forward to increasing the average specific impulse of rocket vehicles is to employ the atmosphere for both oxidiser and reaction mass for part of the ascent. This is an old idea dating back to the 1950s and revitalised by the emergence of the BAe/Rolls Royce HOTOL project in the 1980s [2]. The following sections will review the main airbreathing engine candidates and trace the design background of precooled hybrid airbreathing rockets. 5.Ramjet and Scramjet Engines A ramjet engine is from a thermodynamic viewpoint a very simple device consisting of an intake, combustion and nozzle system in which the cycle pressure rise is achieved purely by ram compression. Consequently a separate propulsion system is needed to accelerate the vehicle to speeds at which the ramjet can takeover (Mach 1-2). A conventional hydrogen fuelled ramjet with a subsonic combustor is capable of operating up to around Mach 5-6 at which point the limiting effects of dissociation reduce the effective heat addition to the airflow resulting in a rapid loss in nett thrust. The idea behind the scramjet engine is to avoid the dissociation limit by only partially slowing the airstream through the intake system (thereby reducing the static temperature rise) and hence permitting greater useful heat addition in the now supersonic combustor. By this means scramjet engines offer the tantalising prospect of achieving a high specific impulse up to very high Mach numbers. The consequent de crease in the rocket powered à ¢Ã‹â€ Ã¢â‚¬  V would translate into a large saving in the mass of liquid oxygen required and hence possibly a reduction in launch mass. Although the scramjet is theoretically capable of generating positive nett thrust to a significant fraction of orbital velocity it is unworkable at low supersonic speeds. Therefore it is generally proposed that the internal geometry be reconfigured to function as a conventional ramjet to Mach 5 followed by transition to scramjet mode. A further reduction of the useful speed range of the scramjet results from consideration of the nett vehicle specific impulse ((thrust-drag)/fuel flow) in scramjet mode as compared with rocket mode. This tradeoff shows that it is more effective to shut the scramjet down at Mach 12-15 and continue the remainder of the ascent on pure rocket power. Therefore a scramjet powered launcher would have four main propulsion modes: a low speed accelerator mode to ramjet followed by scramjet and finally rocket mode. The proposed low speed propulsor is often a ducted ejector rocket system employing the scramjet injector struts as both ejector nozzles to entrain air at low speeds and later as the rocket combustion chambers for the final ascent. Whilst the scramjet engine is thermodynamically simple in conception, in engineering practice it is the most complex and technically demanding of all the engine concepts discussed in this paper. To make matters worse many studies including the recent ESA Winged Launcher Concept study have failed to show a positive payload for a scramjet powered SSTO since the fundamental propulsive characteristics of scramjets are poorly suited to the launcher role. The low specific thrust and high specific impulse of scramjets tends to favour a cruise vehicle application flying at fixed Mach number over long distances, especially since this would enable the elimination of most of the variable geometry. Scramjet engines have a relatively low specific thrust (nett thrust/airflow) due to the moderate combustor temperature rise and pressure ratio, and therefore a very large air mass flow is required to give adequate vehicle thrust/weight ratio. However at constant freestream dynamic head the captured air mass flow reduces for a given intake area as speed rises above Mach 1. Consequently the entire vehicle frontal area is needed to serve as an intake at scramjet speeds and similarly the exhaust flow has to be re-expanded back into the original streamtube in order to achieve a reasonable exhaust velocity. However employing the vehicle forebody and aftbody as part of the propulsion system has many disadvantages: The forebody boundary layer (up to 40% of the intake flow) must be carried through the entire shock system with consequent likelihood of upsetting the intake flow stability. The conventional solution of bleeding the boundary layer off would be unacceptable due to the prohibitive momentum drag penalty. The vehicle undersurface must be flat in order to provide a reasonably uniform flowfield for the engine installation. The flattened vehicle cross section is poorly suited to pressurised tankage and has a higher surface area/volume than a circular cross section with knock-on penalties in aeroshell, insulation and structure mass. Since the engine and airframe are physically inseparable little freedom is available to the designer to control the vehicle pitch balance. The single sided intake and nozzle systems positioned underneath the vehicle generate both lift and pitching moments. Since it is necessary to optimise the intake and nozzle system geometry to maximise the engine performance it is extremely unlikely that the vehicle will be pitch balanced over the entire Mach number range. Further it is not clear whether adequate CG movement to trim the vehicle could be achieved by active propellant transfer. Clustering the engines into a compact package underneath the vehicle results in a highly interdependant flowfield. An unexpected failure in one engine with a consequent loss of internal flow is likely to unstart the entire engine installation precipitating a violent change in vehicle pitching moment. In order to focus the intake shock system and generate the correct duct flow areas over the whole Mach range, variable geometry intake/combustor and nozzle surfaces are required. The large variation in flow passage shape forces the adoption of a rectangular engine cross section with flat moving ramps thereby incurring a severe penalty in the pressure vessel mass. Also to maximise the installed engine performance requires a high dynamic pressure trajectory which in combination with the high Mach number imposes severe heating rates on the airframe. Active cooling of significant portions of the airframe will be necessary with further penalties in mass and complexity. Further drawbacks to the scramjet concept are evident in many areas. The nett thrust of a scramjet engine is very sensitive to the intake, combustion and nozzle efficiencies due to the exceptionally poor work ratio of the cycle. Since the exhaust velocity is only slightly greater than the incoming freestream velocity a small reduction in pressure recovery or combustion efficiency is likely to convert a small nett thrust into a small nett drag. This situation might be tolerable if the theoretical methods (CFD codes) and engineering knowledge were on a very solid footing with ample correlation of theory with experiment. However the reality is that the component efficiencies are dependant on the detailed physics of poorly understood areas like flow turbulence, shock wave/boundary layer interactions and boundary layer transition. To exacerbate this deficiency in the underlying physics existing ground test facilities are unable to replicate the flowfield at physically representative sizes , forcing the adoption of expensive flight research vehicles to acquire the necessary data. Scramjet development could only proceed after a lengthy technology program and even then would probably be a risky and expensive project. In 1993 Reaction Engines estimated that a 130 tonne scramjet vehicle development program would cost $25B (at fixed prices) assuming that the program proceeded according to plan. This program would have included two X planes, one devoted to the subsonic handling and low supersonic regime and the other an air dropped scramjet research vehicle to explore the Mach 5-15 regime. 6.Turbojets, Turborockets and Variants In this section are grouped those engines that employ turbocompressors to compress the airflow but without the aid of precoolers. The advantage of cycles that employ onboard work transfer to the airflow is that they are capable of operation from sea level static conditions. This has important performance advantages over engines employing solely ram compression and additionally enables a cheaper development program since the mechanical reliability can be acquired in relatively inexpensive open air ground test facilities. 6.1 Turbojets Turbojets (Fig. 1) exhibit a very rapid thrust decay above about Mach 3 due to the effects of the rising compressor inlet temperature forcing a reduction in both flow and pressure ratio. Compressors must be operated within a stable part of their characteristic bounded by the surge and choke limits. In addition structural considerations impose an upper outlet temperature and spool speed limit. As inlet temperature rises (whilst operating at constant Wà ¢Ã‹â€ Ã… ¡T/P and N/à ¢Ã‹â€ Ã… ¡T) the spool speed and/or outlet temperature limit is rapidly approached. Either way it is necessary to throttle the engine by moving down the running line, in the process reducing both flow and pressure ratio. The consequent reduction in nozzle pressure ratio and mass flow results in a rapid loss in nett thrust. However at Mach 3 the vehicle has received an insufficient boost to make up for the mass penalty of the airbreathing engine. Therefore all these cycles tend to be proposed in conjunction with a subsonic combustion ramjet mode to higher Mach numbers. The turbojet would be isolated from the hot airflow in ramjet mode by blocker doors which allow the airstream to flow around the core engine with small pressure loss. The ramjet mode provides reasonable specific thrust to around Mach 6-7 at which point transition to rocket propulsion is effected. Despite the ramjet extension to the Mach number range the performance of these systems is poor due mainly to their low thrust/weight ratio. An uninstalled turbojet has a thrust/weight ratio of around 10. However this falls to 5 or less when the intake and nozzle systems are added which compares badly with a H2/O2 rocket of 60+. 6.2 Turborocket The turborocket (Fig. 2) cycles represent an attempt to improve on the low thrust/weight of the turbojet and to increase the useful Mach number range. The pure turborocket consists of a low pressure ratio fan driven by an entirely separate turbine employing H2/O2 combustion products. Due to the separate turbine working fluid the matching problems of the turbojet are eased since the compressor can in principle be operated anywhere on its characteristic. By manufacturing the compressor components in a suitable high temperature material (such as reinforced ceramic) it is possible to eliminate the ramjet bypass duct and operate the engine to Mach 5-6 whilst staying within outlet temperature and spool speed limits. In practice this involves operating at reduced nondimensional speed N/à ¢Ã‹â€ Ã… ¡T and hence pressure ratio. Consequently to avoid choking the compressor outlet guide vanes a low pressure ratio compressor is selected (often only 2 stages) which permits operation over a wider flow range. The turborocket is considerably lighter than a turbojet. However the low cycle pressure ratio reduces the specific thrust at low Mach numbers and in conjunction with the preburner liquid oxygen flow results in a poor specific impulse compared to the turbojet. 6.3 Expander Cycle Turborocket This cycle is a variant of the turborocket whereby the turbine working fluid is replaced by high pressure regeneratively heated hydrogen warmed in a heat exchanger located in the exhaust duct (Fig. 3). Due to heat exchanger metal temperature limitations the combustion process is normally split into two stages (upstream and downstream of the ma- LHLH LOx/LH2 Fig. 1 Turbo-ramjet Engine (with integrated rocket engine). LOx/LH2LH2 LOx/LH2 Fig. 2 Turborocket. LH2LOx/LH2 Fig. 3 Turbo-expander engine. trix) and the turbine entry temperature is quite low at around 950K. This variant exhibits a moderate improvement in specific impulse compared with the pure turborocket due to the elimination of the liquid oxygen flow. However this is achieved at the expense of additional pressure loss in the air ducting and the mass penalty of the heat exchanger. Unfortunately none of the above engines exhibit any performance improvement over a pure rocket approach to the SSTO launcher problem, despite the wide variations in core engine cycle and machinery. This is for the simple reason that the core engine masses are swamped by the much larger masses of the intake and nozzle systems which tend to outweigh the advantage of increased specific impulse. Due to the relatively low pressure ratio ramjet modes of these engines, it is essential to provide an efficient high pressure recovery variable geometry intake and a variable geometry exhaust nozzle. The need for high pressure recovery forces the adoption of 2 dimensional geometry for the intake system due to the requirement to focus multiple oblique shockwaves over a wide mach number range. This results in a very serious mass penalty due to the inefficient pressure vessel cross section and the physically large and complicated moving ramp assembly with its high actuation loads. Similarly the exhaust nozzle geometry must be capable of a wide area ratio variation in order to cope with the widely differing flow conditions (Wà ¢Ã‹â€ Ã… ¡T/P and pressure ratio) between transonic and high Mach number flight. A further complication emerges due to the requirement to integrate the rocket engine needed for the later ascent into the airbreathing engine nozzle. This avoids the prohibitive base drag penalty that would result from a separate dead nozzle system as the vehicle attempted to accelerate through transonic. 7. Liquid Air Cycle Engines (LACE) and Air Collection Engines (ACE) Liquid Air Cycle Engines were first proposed by Marquardt in the early 1960s. The simple LACE engine exploits the low temperature and high specific heat of liquid hydrogen in order to liquify the captured airstream in a specially designed condenser (Fig. 4). Following liquifaction the air is relatively easily pumped up to such high pressures that it can be fed into a conventional rocket combustion chamber. The main advantage of this approach is that the airbreathing and rocket propulsion systems can be combined with only a single nozzle required for both modes. This results in a mass saving and a compact installation with efficient base area utilisation. Also the engine is in principle capable of operation from sea level static conditions up to perhaps Mach 6-7. LH2 LO2 Liquid Air Turbopump Fig. 4 Liquid Air Cycle Engine (LACE). The main disadvantage of the LACE engine however is that the fuel consumption is very high (compared to other airbreathing engines) with a specific impulse of only about 800 secs. Condensing the airflow necessitates the removal of the latent heat of vaporisation under isothermal conditions. However the hydrogen coolant is in a supercritical state following compression in the turbopump and absorbs the heat load with an accompanying increase in temperature. Consequently a temperature pinch point occurs within the condenser at around 80K and can only be controlled by increasing the hydrogen flow to several times stoichiometric. The air pressure within the condenser affects the latent heat of vaporisation and the liquifaction temperature and consequently has a strong effect on the fuel/air ratio. However at sea level static conditions of around 1 bar the minimum fuel/air ratio required is about 0.35 (ie: 12 times greater than the stoichiometric ratio of 0.029) assuming that the hydrogen had been compressed to 200 bar. Increasing the air pressure or reducing the hydrogen pump delivery pressure (and temperature) could reduce the fuel/ air ratio to perhaps 0.2 but nevertheless the fuel flow remains very high. At high Mach numbers the fuel flow may need to be increased further, due to heat exchanger metal temperature limitations (exacerbated by hydrogen embrittlement limiting the choice of tube materials). To reduce the fuel flow it is sometimes proposed to employ slush hydrogen and recirculate a portion of the coolant flow back into the tankage. However the handling of slush hydrogen poses difficult technical and operational problems. From a technology standpoint the main challenges of the simple LACE engine are the need to prevent clogging of the condenser by frozen carbon dioxide, argon and water vapour. Also the ability of the condenser to cope with a changing g vector and of designing a scavenge pump to operate with a very low NPSH inlet. Nevertheless performance studies of SSTOs equipped with LACE engines have shown no performance gains due to the inadequate specific impulse in airbreathing mode despite the reasonable thrust/weight ratio and Mach number capability. The Air Collection Engine (ACE) is a more complex variant of the LACE engine in which a liquid oxygen separator is incorporated after the air liquifier. The intention is to takeoff with the main liquid oxygen tanks empty and fill them during the airbreathing ascent thereby possibly reducing the undercarriage mass and installed thrust level. The ACE principal is often proposed for parallel operation with a ramjet main propulsion system. In this variant the hydrogen fuel flow would condense a quantity of air from which the oxygen would be separated before entering the ramjet combustion chamber at a near stoichiometric mixture ratio. The liquid nitrogen from the separator could perform various cooling duties before being fed back into the ramjet airflow to recover the momentum drag. The oxygen separator would be a complex and heavy item since the physical properties of liquid oxygen and nitrogen are very similar. However setting aside the engineering details, the basic thermodynamics of the ACE principal are wholly unsuited to an SSTO launcher. Since a fuel/air mixture ratio of approximately 0.2 is needed to liquify the air and since oxygen is 23.1% of the airflow it is apparent that a roughly equal mass of hydrogen is required to liquify a given mass of oxygen. Therefore there is no saving in the takeoff propellant loading and in reality a severe structure mass penalty due to the increased fuselage volume needed to contain the low density liquid hydrogen. 8. Precooled Hybrid Airbreathing Rocket Engines This last class of engines is specifically formulated for the SSTO propulsion role and combines some of the best features of the previous types whilst simultaneously overcoming their faults. The first engine of this type was the RB545 powerpla

Floods of 1998 in Bangladesh and Shrewsbury :: Papers

Floods of 1998 in Bangladesh and Shrewsbury Causes, Effects and responses to flooding In Shrewsbury The Severn Valley floods, Shrewsbury, UK 1998: Causes ====== The human causes of the floods were summed up by the then Shadow Countryside Minister Tim Yeo MP, he said 'the flooding had increased because of the housing developments on Greenfield sites.' By this he means that by covering the land with tarmac in urban areas humans have increased the rate of surface runoff and decreased the saturation levels of the ground. When surface runoff is high rainwater reaches the river faster. It would appear that the speed in which the water reached the river was too fast for the river to handle. The river filled up reaching bank-full discharge and then overflowing its banks onto the flood plain. The flood plain of the River Severn is built on, therefore, when the river floods it floods onto residential areas. With the building of these urban areas the amount of vegetation in the area surrounding the river was reduced, this affects the river two ways. It reduces the amount of interception, which in turn increases the speed of runoff into the river. The lack of vegetation also leads to the saturation of the ground. During the months of October and November the rainfall in the Severn Valley was high, as the water soaked into the ground it became saturated. More vegetation in the area would have meant the vegetation using the water would have decreased the amount of water in ground storage. Physical factors of the flood in 1998 are many; however, the most important one was the amount of rainfall. In October 1998 many areas received record amounts of rainfall caused by a 'hurricane'. This 'hurricane' brought very heavy rain and strong winds. The fact the rain was heavy means that the river did not have time to dissipate the water quick enough and the runoff was too fast, making the river rise t such an extent that it flooded.

Genetically Modified Foods and the Labeling Debate Essay

There has been an ongoing debate between consumers and the government regarding the use of Genetically Modified Foods in the market today. â€Å"Since the introduction of the â€Å"Flavr Savr† tomato, biotechnology companies continue to introduce genetically engineered agricultural products to consumers† (Whittaker). The â€Å"Flavr Savor† tomato was the first food available to consumers that was produced using technology involving the recombinant DNA techniques in 1993. This was the dawn of a new generation in food production, and thus a whole new world of genetically engineered foods. At the present time the government, more specifically, the United States Food and Drug Administration (FDA) has not regulated labeling products that contain genetically engineered foods. Currently the policy for labeling all consumer products must meet the standards of the safety and nutritional assessment. The evaluations of genetically engineered foods by legal authority require that bioengineered foods must meet the same standards set forth for all imported and exported foods marked for human and animal consumption and according to the US FDA genetically modified (GM) foods meet these guidelines. Since the early 1990’s scientists has been researching new and improved techniques to bring plumper, juicer and insecticide resistant agricultural products to all consumers. But research such as this is nothing new to the scientific community and for over 50 years techniques have been used to create strains of wheat, rice, pears and many more crop species to create high yielding products that are capable of growing anywhere and anytime of the year. Currently, only one tenth of the world actually uses GM plants with the countries of Canada, US, Brazil and Argentina growing 90 percent of the GM crops (Freedman). With the majority of these crops being produced in North America, the US is seeing GM foods everywhere and this is drawing attention to different agencies and groups pushing to educate the public by labeling any products that contain genetically engineered foods. The US Food and Drug Administration has been dealing with the battle against labeling products with genetically modified organisms (GMO) for years, but regardless of the consistent scrutiny the FDA sticks firmly to the current regulations that govern the labeling of all foods for human and animal consumption. Under the Federal Food, Drug and Cosmetic (FD&C) Act, which drives the FDA’s safety regulations for food and food ingredients, â€Å"unless a significant safety risk exists or there is a sincere need for consumers to distinguish between food products before purchase, the FDA hesitates to mandate labeling of food products† (Leggio). Joseph A. Levitt, Director of the Center for Food Safety and Applied Nutrition with the US Food and Drug Administration states in his â€Å"Should the FDA Adopt a Stricter Policy on Genetically Engineered Foods? † testimony that â€Å"bioengineered foods and food ingredients must adhere to the same standards of safety under the FD&C act that apply to their conventionally bred counterparts† (Levitt, 81). With the strict laws set forth, the FDA remains consistent with its decision to maintain their current labeling program as it adheres to all safety standards of any food for consumption. The US FDA also assures the public that they have done significant research for decades on biotechnology foods to ensure it is safe for consumers, and additional testing is conducted years prior to the release of a GM product to the shelves. Scientists address all of the potential concerns to include the potential to adding new allergy causing proteins, removing vital nutrients and the possibility of introducing toxins, in these studies to ensure that unexpected results do not occur, â€Å"this testing provides a way to detect such changes at the development stage† (Levitt, 79) and it will also delay any release of products until they are able to find a solution. The FDA takes such precautions and studying all aspects of this technology to be confident that the risks are non-existent. Although the government has provided the public with research, publications, testimonies and scientific proof that the current law governing the labeling of food and animal products is appropriate and doesn’t require change, there is still much concern of the risks that the technology poses to humans. Barbara Boxer, a US Senator from California, introduced the Genetically Engineered Food Right-To-Know Act in 2001 in her testimony in â€Å"Should the FDA Adopt a Stricter Policy on Genetically Engineered Foods? † which states â€Å"all foods containing or produced with genetically engineered material bear a neutral label† (Boxer, 76). This act was created based on the lack of data and concerns that GM products are introducing risks of exposure to many health issues to include food allergens, lack of nutrition and toxic ailments. These claims are legitimate, however, the US FDA does take precautions as stated by Joseph A. Levitt, specifically with these risks while conducting trials during the developing stages of the product. In 2011 there was a petition filed against the FDA which warranted the need for labeling of GM products. According to this petition â€Å"consumers are misled when food labels do not differentiate foods with known health properties from novel foods with unknown health consequences† (Burgaard). An example of such health concerns come from a study performed in Scotland at the Rowett Institute in 1998. A plant biochemist named Arpad Pusztai conducted an experiment on rats who consumed a genetically engineered potato and his experiment concluded that the rats that were fed the modified potato â€Å"suffered growth and immune system-related changes† (Freedman). Ironically, the genetically modified potato used in this study â€Å"was not intended for human consumption — it was, in fact, designed to be toxic for research purposes,† (Freedman) discrediting the research altogether. Additionally, â€Å"American Medical Association, the National Academy of Sciences, the World Health Organization, and more than twenty-five Nobel Prize-winning scientists have concluded that there is no scientific evidence that GM food carries any risk to human health and that genetically engineered crops are safe,† (Burgaard) which ties into the overall nutrition and safety assessment that genetically engineered foods meet the same standards that imported and exported foods at held too. In the end, the US Food and Drug Administration stands by the current law governing the policy on labeling genetically modified foods. They maintain their standing on mandated labeling even under the microscope of doubters, but most importantly the â€Å"FDA’s process for evaluating bioengineered foods is one in which the public can have confidence that food biotechnology products must meet the law’s safety standards† (Maryanski). The FDA cares deeply of the health and wellbeing of the consumers in America and strive to meet the needs of the public in both food and nutrition education. Until the studies show significant risks or changes in the GM products warranting the need to readdress the process, the government and the US Food and Drug Administration believe their approach is relevant and remain firm to the present policies. Annotated Bibliography Whittaker, Michael A. â€Å"Reevaluating The Food And Drug Administration’s Stand On Labeling Genetically Engineered Foods. † San Diego Law Review 35. 4 (1998): 1215. Academic Search Premier. Web. 2 Jan. 2014. This journal review argues that the United States Food and Drug Administration (FDA) must reconsider its position on the labeling of genetically engineered food as well as consumer perceptions of the threat posed by genetically engineered foods. Freedman, David H. â€Å"Are Engineered Foods Evil?. † Scientific American 309. 3 (2013): 80-85. Environment Complete. Web. 2 Jan. 2014. This article discusses the debate over the safety of genetically modified (GM) crops. It covers comments from agricultural and environmental economist at the University of California, Berkeley, David Zilberman, on the benefits of GM foods compared to their health risks, a ban on GM crops by the European Union (EU), and the difference between selective plant breeding and mutagenic techniques. Leggio, Kelly A. â€Å"Limitations On The Consumer’s Right To Know: Settling The Debate Over Labeling Of Genetically Modified Foods In The United States. † San Diego Law Review 38. 3 (2001): 893. Academic Search Premier. Web. 3 Jan. 2014. This journal review supports the decision of the United States Food and Drug Administration (FDA) to reject mandatory labeling of genetically modified foods as a solution to accommodate consumer fears. There is a description of an approach designed to evaluate whether mandatory initiatives are appropriate to protect consumer’s right to know and the importance for states to follow guidelines established by the FDA. â€Å"Should The FDA Adopt A Stricter Policy On Genetically Engineered Foods? PRO/CON. † Congressional Digest 80. 3 (2001): Pages 76-95. Academic Search Premier. Web. 2 Jan. 2014. This is a two part article that discusses genetically engineered foods and the potential need to adopt a more strict policy. The articles provided information from the perspective of the US Food and Drug Administration (FDA) Joseph A. Levitt, the director of the Center of Food Safety and Applied Nutrition and US Senator, Barbara Boxer who speaks on behalf of the Genetically Engineered Food Right-to-Know Act and additional interviews that were conducted to give the audience an overall understanding of both sides of the debate. Burgaard, Sudhir. â€Å"The Labeling Of Genetically Modified Foods Debate. † Natural Resources & Environment 28. 1 (2013): 55-57. Environment Complete. Web. 2 Jan. 2014. This article focuses on the debate on labeling of genetically modified (GM) food which reflects food safety concerns in the U. S. It highlights various legal issues related to use of GM foods which includes increased risk of antibiotic resistant bacteria, increased use of pesticides, and environmental effects. It briefs the audience about the Center for Food Safety filing a legal petition with the U. S. Food and Drug Administration regarding labeling of genetically engineered food. Maryanski, . James H. , Ph D. â€Å"News & Events. † Genetically Engineered Foods. US Food and Drug Administration, 19 Oct. 1999. Web. 2 Jan. 2014. This testimony is from the perspective of the Biotechnology Coordinator with the US Food and Drug Administration (FDA) that discusses the current regulations governing genetically engineered foods and the process that dictates what and how determines what a DNA derived food is labeled. It includes a variety of examples that justifies the current labeling regulations and why GM Foods may not require additional information for the consumers.

Late payment/collections

Dear Sir/Madam, I found my credit rating to be really poor because of a few late payments and collections that happened on my accounts. Even though there were a few mistakes and over sights from my side, most of the recent late payments were due to technical difficulties faced by the concerned banks. I made payment arrangements for $3869 to clear the account with Citi Financial retail. But the payment was delayed since the concerned department could not locate my account in their system.I faced problems with payments to WEB Bank and Qwest, since I was out of town. However I had an arrangement to pay $100 per month to WEB Bank and settle the remaining amount by January 2011. I was never intimated by Qwest regarding any outstanding amount whatsoever despite updating them about the change of address. I am ready to settle with Telenational Communications, although I never maintained an account with them.I had rented out my house after clearing all the bills with Colorado Springs Utilitie s till July 2010. The outstanding amount of $55 was supposed to be settled by the tenant. I have missed few payment deadlines due to oversight. The PAID accounts to THD/CBSD, Colorado Springs Utilities and the credit card accounts with Chase and Service credit Union have been cleared and the recent late payment was in September 2008.The accounts with Service Credit Union, ENT Federal CU, USAA, Military star, Chase Mortgage and Capital One Note Loan have been settled completely and in many cases the payment was late by a couple of days. But the numbers of such instances are few and most of them have occurred during my re-deployment. Since all the above mentioned outstanding has been cleared and considering the circumstances under which many of the incidents happened, I request you to kindly re-evaluate my credit score and update my credit report with the relevant details.

Serian Synogoges essays

Serian Synogoges essays Architecture plays a very important role in a culture, and from its remains, historians can gain a wealth of information. It determines the wealth of the community, the weather conditions and many other things. Not only can historians learn what it was like in that area at that time, but also they can learn from it to improve our area now. For example, the Romans built curved roads and sewers to prevent flooding and currently we also build our roads similarly. Another example can be the columns the Greeks used to build; now the White house and many other buildings are built in a Greek style. In fact, the entire Washington D.C. is built just like Paris; it is built in a circle around the White House, as Paris is built around the Eiffel Tower. Architecture and the arts have such power over people that Jews are thought to have horns because of a misinterpretation by Leonardo Divenchi, who portrayed Moses with horns. Now well take a look at architecture from a religious point of view. During the late Fifteenth century, refugees from Spain escaped to Muslim countries, mainly the Ottoman Empire. With them they brought the Sephardic traditions and culture and it quickly spread throughout the Mediterranean region. The Sephardic tradition eventually dominated the Syrian synagogue design and its architecture. Today, this beautiful architecture still remains in the Syrian community in Brooklyn. During the Ottoman period, the basilica form was popular. The Syrian synagogue usually had a wide central aisle and two side aisles. Arcades supported by columns separate it. Different parts of the room would be elevated, especially the tevah for illumination purposes. Many of the synagogues of Syria were very decorative; even the mandatory utensils of the synagogue, such as the lightbox, which was used to give off light to read the torah, would be very fancy. ...

Reflexive Verbs and Pronouns in Spanish

Reflexive Verbs and Pronouns in Spanish I hit myself. Bill hurt himself. They saw themselves. Did you find yourself? What do the above sentences have in common? Obviously, they all have pronouns that end in -self or -selves. Less obviously, but as a corollary, they all use pronouns that stand for the subject of the sentence. In other words, the subjects and objects of the verbs in the above sentences refer to the same person. Another way of putting this might be that the subject of each sentence is engaging in some action that affects the same person or persons. If you can comprehend that, you understand the basic concept behind the grammar of reflexive pronouns and verbs in Spanish. Reflexive pronouns in Spanish are closely related to direct and indirect-object pronouns, following the same rules of word order and using most of the same pronouns. The Reflexive Pronouns of Spanish Here are the reflexive pronouns in Spanish with a simple example of each and a translation: First-person singular: me - myself - Me oà ­. I heard myself.Second-person singular familiar: te - yourself - Te oiste. You heard yourself.Second-person singular formal, third-person singular: se - yourself, himself, herself, itself, oneself - Ella se oyà ³. She heard herself. Èl se oyà ³. He heard himself.  ¿Se oye usted? Do you hear yourself?First-person plural: nos - ourselves - Nos oà ­mos. We heard ourselves.Second-person plural familiar: os - yourselves - Os oà ­steis. You heard yourselves.Second-person plural formal, third-person plural: se - yourselves, themselves - Se oyeron. They heard themselves. Verbs Used Primarily or Only in the Reflexive One major difference between Spanish and English in this matter is that in Spanish many verbs exist only or primarily in the reflexive form. There is only one common English verb that shares this characteristic: to perjure oneself. Examples of verbs that exist primarily or frequently in the reflexive form are acostarse (to go to bed), divertirse (to have a good time), ducharse (to take a shower), enamorarse (to fall in love), enojarse (to get angry), levantarse (to get up), sentarse (to sit down), sentirse (to feel), and vestirse (to get dressed). It is also common to use the reflexive form when performing some action on a part of the body. Examples include secarse el cabello (to dry ones hair) and lavarse las manos (to wash ones hands). Note that the infinitive form of reflexive verbs is usually stated by placing -se at the end of the infinitive. Translating Reflexive Verbs Note that for many of these verbs it is not necessary to translate the reflexive pronoun into English. Se acostà ³ a las nueve, she went to bed at 9. Me siento triste, I feel sad. But with many verbs, especially those that are less frequently used in the reflexive, the pronoun must be translated.  ¿Te ves en el espejo? Do you see yourself in the mirror? And in still other cases, you can translate with or without translating the pronoun. Se vistià ³ en su coche, he got dressed in his car, or he dressed himself in his car. Sometimes, the reflexive can be translated using each other when in the plural form. Nos miramos, we looked at each other. Se escucharon, they listened to each other (or to themselves, depending on the context). Romeo y Julieta se amaron, Romeo and Juliet loved each other. As usual, context should be a key guide when translating to English. In some cases, putting a verb in the reflexive form can make it more intense, as we do sometimes in English by adding a particle. For example, ir means to go, but irse is usually translated to go away. Similarly, comer means to eat, but comerse might be translated as to eat up, as in se comià ³ cinco tacos, he ate up five tacos. Often in Spanish the reflexive form is used where in English we would use a passive form of a verb. Se cerrà ³ la puerta. The door was closed (a literal translation would be the door closed itself). Se perdieron los boletos, the tickets got lost. Translating "-self" to Spanish Sometimes in English we use the reflexive pronouns as a means of emphasizing the subject rather than as a true reflexive, as in the sentence, I myself performed the task or I performed the task myself. In such cases, the reflexive form should not be used in the Spanish translation. The first sentence would typically be translated using mismo: Yo mismo hice la tarea. The second sentence also could be translated by paraphrasing its meaning: Hice la tarea sin ayuda (literally, I did the task without help). Key Takeaways In reflexive sentences, the direct object pronoun of a verb represents the same person or thing as the subject.Spanish reflexive pronouns are used much like English -self words such as myself or ourselves when those words are used reflexively.Many Spanish verbs are used only or mostly in the reflexive form.

Convert Molarity to Parts Per Million Example Problem

Convert Molarity to Parts Per Million Example Problem Molarity and parts per million (ppm) are two units of measurement used to describe the concentration of a chemical solution. One mole is equivalent to the molecular or atomic mass of the solute. Parts per million, of course, refers to the number of molecules of solute per million parts of a solution. Since both of these units of measurement are commonly referred to in chemistry, its helpful to understand how to convert from one to the other. This example problem demonstrates how to convert molarity to parts per million. Molarity to ppm Problem A solution contains Cu2 ions at a concentration of 3 x 10 -4 M. What is the Cu2 concentration in ppm? Solution ï » ¿Parts per million, or ppm, is a measure of the amount of a substance per million parts of a solution.1 ppm 1 part substance X/ 1 x 106 parts solution1 ppm 1 g X/ 1 x 106 g solution1 ppm 1 x 10-6 g X/ g solution1 ppm 1 ÃŽ ¼g X/ g solution If the solution is in water and the density of water 1 g/mL then1 ppm 1 ÃŽ ¼g X / mL solution Molarity uses moles/L, so the mL need to be converted to L1 ppm 1 ÃŽ ¼g X /( mL solution)x(1 L/1000 mL)1 ppm 1000 ÃŽ ¼g X / L solution1 ppm 1 mg X/L solution We know the molarity of the solution, which is in moles/L. We need to find mg/L. To do this, convert moles to mg.moles/L of Cu2 3 x 10-4 M From the periodic table, the  atomic mass of Cu 63.55 g/molmoles/L of Cu2 (3 x 10-4 mol x 63.55 g/mol)/Lmoles/L of Cu2 1.9 x 10-2 g/L We want mg of Cu2, somoles/L of Cu2 1.9 x 10-2 g/L x 1000 mg/1 gmoles/L of Cu2 19 mg/LIn dilute solutions 1 ppm 1 mg/L.moles/L of Cu2 19 ppm Answer:A solution with 3 x 10-4 M concentration of Cu2 ions is equivalent to 19 ppm. ppm to Molarity Conversion Example You can perform the unit conversion the other way, too. Remember, for dilute solutions, you can use the approximation that 1 ppm is 1 mg/L. Use the atomic masses from the periodic table to find the molar mass of the solute. For example, lets find the ppm concentration of chloride ions in a 0.1 M NaCl solution. A  1 M solution of sodium chloride (NaCl) has a molar mass 35.45 for chloride, which you find from looking up the atomic mass of chlorine on the periodic table and noting there is only 1 Cl ion per NaCl molecule. The mass of sodium doesnt come into play since were only looking at chloride ions for this problem.  So, you know have the relation: 35.45 gram/mole or 35.5 g/mol You either move the decimal point over one space to the left or multiply this value times 0.1 to get the number of grams in a 0.1 M solution, to give you 3.55 grams per liter for a 0.1 M NaCl solution. 3.55 g/L is the same as 3550 mg/L Since 1 mg/L is about 1 ppm: A 0.1 M solution of NaCl has a concentration of about 3550 ppm Cl ions.

Power point Essay Example | Topics and Well Written Essays - 1000 words

Power point - Essay Example ort can disrupt the functioning of the entire set up at the airport, cause tensions and insecurity of thousands of passengers, and millions of newspaper readers and electronic media read such news reports. As for one’s health and the health of family members, the concern is greatest, as never before. One needs to go the root causes. To illustrate this by an example, look at the mosquito issue and how it is tackled. Mosquitoes thrive on the blood of human beings and hundreds of pesticide manufacturing companies thrive on the blood of mosquitoes. Some of them are big multinationals. Flashy advertisements of their product take of the mosquitoes. Take care how and how long? If you kill the mosquitoes today in your home or office premises, a new batch of mosquitoes is waiting to take over the blood-sucking operations. To find the tangible solutions, one needs to go to the root cause. The root cause of the breeding of mosquitoes is filth. Remove the filth, and give priority to the cleanliness of the premises. The mosquitoes will say farewell to such clean premises for ever. I am giving this fairly long introduction to set your mind thinking, as to how we miss the basics and entertain the superficial details. One month from today, our company will be reaching an important milestone to address to the basic causes of many types of diseases that afflict humanity. The detailed research your company has been doing over this product has resulted in stunning and sterling facts. I am telling you about a product, which you know already, but the merits of which you actually you do not know. The product which we are gong to launch is FAME Honey: Now, let us quickly move to the brass track of business and look up some slides as to how we go about the exercise of launching FAME Honey. All these qualities make honey a great product, the importance of which has come to the notice of the researchers and the medical fraternity. Honey is known to increase the resistance power of the

GLOBAL CHALLENGES FOR BUSINESS, MANAGEMENT AND LEADERSHIP Essay - 1

GLOBAL CHALLENGES FOR BUSINESS, MANAGEMENT AND LEADERSHIP - Essay Example Firms are essentially focussing on improving their management practises in an attempt to improve their business processes. The competitive value framework is a model that essentially helps business organizations to generate competitive advantage by enhancing the value proposition of the organization. The model named as one of the most essential and effective business models was proposed by Quinn & Rorhbaugh in 1983 (Competing Values Company, n.d., p.1). Figure 1: Competitive Values Framework According to Koontz & Weihrich (2006) management is defined as â€Å"the process of designing and maintaining an environment in which individuals, working together in groups efficiently accomplish selected aims† (Koontz & Weihrich, 2006, p.5). ... Internal factors largely include the internal strengths, weakness and opportunities of an organization and are largely associated with the operational and process management practices. External factors on the other hand include the political, legal, economic and sociological factors and help generate an impact for the organization. Relational perspectives include the interpersonal elements of inter group relationships while the empirical elements includes the internal business processes for collection and integration of information handling and management. Political and relational elements denote flexibility and stability while the rational and empirical elements ensure control and stability in a business organization (Schuman, 2010). The combined effect of all the above elements or factors determines the nature of effectiveness of the business strategies adopted by the organizations. Each element represents a set of core values of the firm that are largely distinct from the rest of the others. They show the extent to which an organization tries to be flexible and adoptable to the business environment while maintain an internal stability in the organization. The importance of this model in the present day business environment of turbulence can be easily noted from the fact that it largely helps in displaying the pros and cons, the opposing as well as supporting elements of the business strategies and the nature of alternatives before an organization that can largely help in maintaining profitability and adaptability while maintain an overall stability in the business processes and the organization (Cameron, 2009, p.2-3). Application Organisation Name and Challenge The organization selected for the present study is

Is market research necessary for start-up-business Discuss Essay

Is market research necessary for start-up-business Discuss - Essay Example 1998.Marketing Research, P.106, Tata McGraw-Hill ). Business is a very fluid state; its states will never be constant, ever changing from time to time. Because of these constant changes Organizations are always posed with a question, what do I do next? Little can be answered with out any data to support. The collection of such relevant data gathers high importance especially for beginners because before organizations can launch their products they can understand the feasibility of their efforts through market research. 1. Formulating the problem: The very purpose of any marketing research is to identify the problem and its relevance to the organization. An ill defined problem can mislead the entire market research because of poorly defined research objectives. Initially for beginner, problems are plenty in understanding his/her own business and the general market conditions. Question such as whom to market? What to market are the real challenges for an entrepreneur? Marketing research helps in finding solutions for these and also many other issues. The concept of four ‘p’s (product, place, price, people) needs to be answered. 2. Developing Objectives of the research: The objectives of the research should be clear and specific. The objectives should cover the questions regarding the purpose of the study, Method in which the study is to be conducted, the information needs and the sources of information. The concept to be launched into the market whether it is a product or a service needs to be tested. However it is important to decide at which phase of market research the testing can be done. Normally while launching a startup business, businessmen use market research as a launching board for the product or service. Data collected has to be collated in such a way it yields information and the information so gathered can be utilized for preparation of a research report. Normally research analysis will be based on data depicted in the form of graphs and

Discuss whether the company is moving away from its core competency of Essay

Discuss whether the company is moving away from its core competency of being a leading online retailer. Present areas where Amaz - Essay Example Amazon Simple Storage Service (S3): According to Amazon Web Services (2010); S3 is an online data storage service that enables the users to store and retrieve data from anywhere in the world. Amazon Elastic Compute Cloud (EC2): Engleman (2010) stated that initially, Amazon had started selling individual users computing resources from their own data hubs but now they are trying to compete with tech giants, Google and Microsoft, to offer extensive cloud computing power to federal agencies. Microsoft and Google have been in the market for offering web services over a longer period of time as compared to Amazon. Amazon has been a market leader in the field of e-commerce and has possessed the core competency in online retailing since over a decade. Hiner (2009) stated that the respective retailer company acquired technical expertise after developing the infrastructure for their online retailing service; this expertise cannot be compared or competed with the technical skills and experience that are possessed by the high profile teams at Google and Microsoft. The main objective and mission of the two tech giants have been web services or technical products whereas Amazon has always focused on the retailing business. The Amazon’s shift of focus to web services will affect their position as the market leader in online retailing. An

Market structure Essay Example | Topics and Well Written Essays - 1000 words

Market structure - Essay Example The Spangles candy was a fruity boiled sweet with a slight fix about it, the packaging letters were big fat bottomed font, and they came in several flavors. These candies were popular enough that they made their way into pop culture through songs, and cultural references. â€Å"They were launched a few years ago, but didn't seem to take off. The wording on the packaging was in that big fat-bottomed font, the same one that The Goodies used on their opening titles.† (BBC h2g2, 2011) Available market segments include, persons who were born 5 years prior to the initial release of these candies through persons who were born in the late 1960’s, this would include the ages of 63 – 45. Another market segment could be a foreign market base, the youth market, and potential additional markets like comedy fans. Basic objectives for marketing the Spangles branded candy would be to increase product awareness by 20% in the first year, revive the popular side within the first 6 months, decrease customer resistance to buying our product, which would lead to a 50-100 percent increase in sales within the first year. To accomplish these goals we will need to introduce a valid marketing strategy. In the case of this candy we will want to use focused insertion, and narrow advertising structures. It will be important to introduce the product as a special historical re-launch. An additional objective should be the raised awareness of the Mars ® brand name as a result of the campaign, increases of between 10-15% should be realized in the entire Mars ® line which will make the re-launch a success regardless of the eventual outcome of the Spangles line itself. The price should be approximately what it was at the time of its peak popularity for the initial marketing phase; advertising should be done during the most popular hours of television and radio use for the target market. Distribution should be completed at the popular shopping destinations that already car ry other Mars ® products. One potential approach is to use displays that focus on Spangles as the â€Å"Candy you grew up with.† Another possible approach would include different flavours as well as less boisterous yet still â€Å"retro† looking label on the candy itself. Possibly the â€Å"green† approach can be utilized by promoting the use of recycled materials in the wrappings. Another approach could be the use of popular comedians as personalities promoting the cultural aspects from a comedic point of view on television and radio. If the product is marketed with current pop culture icons as spokespersons the additional benefit would be the appeal to the younger generation. By generating a potential new market and by using easily recognized pop culture icons Mars ® could potentially increase their market share not only through the re-launch of the Spangles boiled sweets but also increased interest in current products. If the marketing approach is followe d the potential for name recognition and additional sales of other popular Mars ® products should increase by 15% or more. Additional approaches can be looked to when the initial launch is complete and sales numbers have been returned. A successful re-launch could mean expanded markets in countries where retirees

Management Accounting Assignment Example | Topics and Well Written Essays - 2750 words

Management Accounting - Assignment Example Each of the method has a different approach to evaluating the worth of an investment or project for an organization. Whereas the last three techniques focus on cash flow, the first technique (the accounting rate of return (ARR) also called return on investment (ROI) uses accounting profit during its appraisal calculation, offering a view of the general profitability of the investment project. 1. The accounting rate of return The accounting rate of return also referred to as the return on investment method calculates the estimated general profit or loss concerning an investment project and connects that profit or loss to the amount of capital injected in the project as well as the period for which that investment is required to go. The profit referred to in the appraisal process here is the one that is directly linked to the investment project and, therefore, costs or revenues made elsewhere in the business are not included. There is a minimum rate of return required for any investmen t that a business wants to undertake. This is connected to the business’s cost of capital. ... r the years of life of the investment project and dividing the total life of the investment project in years and the average investment is found by adding the investment in the first year to the remaining value at the end of life of the project and dividing by two. With these two values, we can comfortably calculate the ARR. This calculation gives the uniqueness of product as well as its drawbacks as we can see in the subsequent discussions and comparisons. The main advantages of accounting rate of return are: Accounting rate of return considers the general profitability of the investment project. The method is simple to understand as well as easy to use. The method’s end outcome is expressed in form of a percentage, permitting projects of varying sizes to be compared. The major drawback is: The method is based on the accounting profits and not the cash flows. Calculation of profit as well as capital employed is based on expenditure items, which are treated as revenue (those a ppearing on the profit & loss account) and as capital (appearing on the balance sheet). Even though there are guidelines relating to this area, this practice can be quite subjective. Various accounting policies, for instance, relating to depreciation can generate different figures of profit and capital employed, therefore permitting the profit as well as balance sheet numbers to be manipulated in some way. This is why capital projects are also appraised in terms of cash flows. Accounting rate of return method does not consider the timing of cash flows of the project. For instance, we may have two projects M, and N. Project M may result in an accounting rate of return of 19 percent whereas project N may have ARR of 17 percent. Nevertheless, investment M may be a six year investment whilst

Market structure Essay Example | Topics and Well Written Essays - 1000 words

Market structure - Essay Example The Spangles candy was a fruity boiled sweet with a slight fix about it, the packaging letters were big fat bottomed font, and they came in several flavors. These candies were popular enough that they made their way into pop culture through songs, and cultural references. â€Å"They were launched a few years ago, but didn't seem to take off. The wording on the packaging was in that big fat-bottomed font, the same one that The Goodies used on their opening titles.† (BBC h2g2, 2011) Available market segments include, persons who were born 5 years prior to the initial release of these candies through persons who were born in the late 1960’s, this would include the ages of 63 – 45. Another market segment could be a foreign market base, the youth market, and potential additional markets like comedy fans. Basic objectives for marketing the Spangles branded candy would be to increase product awareness by 20% in the first year, revive the popular side within the first 6 months, decrease customer resistance to buying our product, which would lead to a 50-100 percent increase in sales within the first year. To accomplish these goals we will need to introduce a valid marketing strategy. In the case of this candy we will want to use focused insertion, and narrow advertising structures. It will be important to introduce the product as a special historical re-launch. An additional objective should be the raised awareness of the Mars ® brand name as a result of the campaign, increases of between 10-15% should be realized in the entire Mars ® line which will make the re-launch a success regardless of the eventual outcome of the Spangles line itself. The price should be approximately what it was at the time of its peak popularity for the initial marketing phase; advertising should be done during the most popular hours of television and radio use for the target market. Distribution should be completed at the popular shopping destinations that already car ry other Mars ® products. One potential approach is to use displays that focus on Spangles as the â€Å"Candy you grew up with.† Another possible approach would include different flavours as well as less boisterous yet still â€Å"retro† looking label on the candy itself. Possibly the â€Å"green† approach can be utilized by promoting the use of recycled materials in the wrappings. Another approach could be the use of popular comedians as personalities promoting the cultural aspects from a comedic point of view on television and radio. If the product is marketed with current pop culture icons as spokespersons the additional benefit would be the appeal to the younger generation. By generating a potential new market and by using easily recognized pop culture icons Mars ® could potentially increase their market share not only through the re-launch of the Spangles boiled sweets but also increased interest in current products. If the marketing approach is followe d the potential for name recognition and additional sales of other popular Mars ® products should increase by 15% or more. Additional approaches can be looked to when the initial launch is complete and sales numbers have been returned. A successful re-launch could mean expanded markets in countries where retirees

The One Scene That Sealed Titanics Fate Essay Example for Free

The One Scene That Sealed Titanics Fate Essay Titanic is thought to be one of the most iconic films to ever hit theaters. According to the film industry, the film by James Cameron falls into the realm of an epic romance/disaster genre. Released in 1997, Titanic was an international box office sensation, due to the director providing equal importance to history, fiction, and romance. The film is set in April of 1912, where Jack Dawson played by Leonardo DiCaprio and Rose DeWitt Bukater played by Gloria Stuart and Kate Winslet share a love story that cannot be broken. The movie also gives a historical overview of what happened that dreadful night. This critical analysis of the film Titanic provides an overview that the innovative mode of storytelling (flash back and other techniques) can portray both a love story and the historical background while using a dissolve editing method, in which â€Å"the end of one shot gradually merges into the beginning of the next. The effect is produced by superimposing a fade-out onto a fade-in of equal length of imposing one scene over another† (Petrie and Boggs 160). This editing effect was used at the beginning of the movie, in which at 21:03, the wreckage of the Titanic is seamlessly and effortlessly transformed into the beautiful masterpiece of a ship that it once was. This effect is also used when Jack and Rose are standing together â€Å"flying† on the edge of the Titanic, later to be transformed back into the ship wreck. This scene brings the audience back into the present and shocks them back into the harsh reality that the scene was merely a memory from Rose, and no longer the reality (Titanic1997). The editing in Titanic is truly remarkable, bringing the audience from the future into the past, shocking the audience by showing both first-class and lower-class struggles, and showing not only the love story between Rose and Jack, but the life and death of the Titanic and the two thousand people aboard. Through the use of other film techniques such as editing and camera work, set design, imagery and color, James Cameron created one of the most influential and moving works of art the film world has seen. The editing style and technique brings new life to the cinematography world, and â€Å"rejects the norms of modern Hollywood style† (Butka). In all film elements, visual effects, cinematography, color palette, editing, sound design, and music, contributes to the film as a whole. Cameron, â€Å"who has been pushing the boundaries of the Hollywood classical cinema since The Terminator, finally reached a career high point with Titanic’s synthesis of compelling storytelli ng and dexterous style and technique† (Butka) Visual effects, color, imagery, and set design play an important role in all forms of movie and television. These elements are the core foundation of the overall feeling that the audience experiences when watching a particular film. One particular element of film that impacts the story line is the setting of the scenery. Setting may â€Å"often seem unobtrusive or be taken for granted, it is an essential ingredient in any story and makes an important contribution to the theme of total effect of the film† (Petrie and Boggs 82). The setting of a film should be carefully analyzed because of the effects it has on the interrelationships of the characters, plot, and overall general feeling that the movie brings out in its audience. In Titanic, the setting plays a major role in the fact that the first class citizens were held to a higher standard that the lower class citizens. This set the mood for the rest of the film and sets up the segregation that separates Jack and Rose. The col ors also provide a strict divide between the upper and lower classes aboard the Titanic. The royalty wore brighter, more vibrant colors, as well as more flashy materials, whereas the lower class wore much more torn clothing, all of which were dark and dirty colors. These elements ultimately set the tone for the rest of the movie, and would be a constant struggle for Rose and Jack to keep their bond strong. James Cameron put an emphasis on the difference between these classes in order to give the audience the sense of segregation. James Cameron is a critically acclaimed film director known for some of the biggest box-office hits of all time. A science-fiction fan as a child, Cameron â€Å"went on to produce and direct films including The Terminator, Aliens and Avatar. He has received numerous Academy Awards and nominations for his often large-scale, expensive productions† (Biography Editors). His most noted work, 1997\s Titanic, became the first film â€Å"to earn more than $1 billion and landed 14 Academy Award nominations. Cameron took home three Oscars himself for the project: Best Director, Best Film Editing and Best Picture† (Biography Editors). To re-create one of the greatest disasters at sea in history, â€Å"James Cameron had a special studio built in Mexico, which featured a 17-million-gallon water tank and the 775-foot replica of the Titanic,† this proved to help the film be a successful blockbuster hit (Biography Editors). James Cameron’s techniques used in Titanic becam e immensely popular as the film became popular. Cameron’s own â€Å"documentary urge was so intense, that he created new diving and photographic equipment – at an extraordinary expense for his studio – to achieve textural authenticity by recording and presenting the eighty-five-year-old wreck of his subject. The film, then, like so many other fictional films, says the ultimate compliment to the documentary form: Cameron uses the real thing to inform his reel thing† (Petrie and Boggs 468). The main purpose behind editing a film is to keep the film in continuous motion, regardless if the time periods switch rapidly, much like in Titanic, where Rose goes from being a seventeen year old girl, to a one-hundred year old woman explaining the history of the Titanic as she remembers it. The editing techniques that were used were ultimately used to shock the audience through â€Å"sudden, jarring cuts between the third- and first-class, [which] build the antithesis between the classes and accentuate the conflicts. Some of the examples include: the cut between the steer get berthing space when Jack and Fabrizio (Danny Nucci) first arrive on the ship and Cal’s private promenade deck; the cut between Rose and Jack dancing in the steerage party scene and the first-class smoking lounge (which is such an abrupt change of atmosphere and energy that it comes as quite a cinematic shock to the viewers); the cut between the flooding in the steerage with rats on the run and the pro priety of a first-class corridor that does not even hint at the impending tragedy† (Butka). Throughout the movie, the film consists of scenes mainly from the Jack and Rose era, however in the beginning of the film, the director made use of flashback technique to unearth the romantic story of the lovers in the film. To be specific, the plot moves from present condition (say, 1996) to past (say, 1912) and to present (1996). In the opening scene, the director portrays the effort of Brock Lovett (say, a treasure hunter) to unearth the secret behind a necklace sunk with RMS Titanic in 1912. Gradually, the director portrays the love affair between Rose and Jack. In the end, Rose drops the necklace into the Ocean and returns. The film ends with a fictional reunion between the lovers. Dissolves are very important to the film, â€Å"particularly those between different time periods, and even fades are used occasionally to mark important points in the film (e.g., when Rose finishes her story)’ (Butka) Cameron also uses â€Å"establishing shots regularly, thus preserving a locale orientation for the viewers: not only do we always know exactly where we are, but these establishing shots also help us grasp the ship’s enormous dimensions† (Butka). Even in the period section of the film, â€Å"there is a separation between two distinct photographic styles: â€Å"In the first part, the camerawork is rather polite, graceful and even eloquent. [Carpenter] was trying to reinforce the opulence and beauty of the time with lighting,† (Butka). This eloquent style gives a feeling of tranquility and perfection to the first class shipmates, providing deep segregation to the boat, thus bringing about the conflict of Jack and Rose’s love. This camera and editing style let the audience feel the same way that the characters were feeling, eloquent and fashionable. When looking at the color of the first class section of the boat, â€Å"there is also use of amber, a color Ca meron has not used before; in addition, the first-class sections of the ship are even more colorful, which is undeniably helped by the exquisite costuming† (Butka). In the second part of the film, the camera work and editing becomes much more violent and choppy, showing the struggle the passengers endured as the ship hit the iceberg and ultimately began to sink. The camerawork â€Å"quickly loses that polite edge and segues into this very kinetic, sometimes violent movement. It’s jarring and bumpy, which suggests the panic of the situation. This is a point that Cameron, Carpenter, and Muro worked on together; later in the film, initial smooth and refined camera movements transform into â€Å"less elegant and more nervous. There’s a lot more handheld work and Steadicam, and its rough† (Butka). The overall production of the Titanic came at quite a cost but was a tremendous success, to say the least. Titanic’s production was a â€Å"famously difficult and complex one, a shoot on an almost unprecedented scale which featured tough technical challenges and which was overseen by a director who knew exactly what he wanted and who demanded the utmost from everyone until he got it, but it was a tough journey to get there† (Braund). Production of the film began in 1995, when â€Å"Cameron shot footage of the real wreck of the RMS Titanic. He envisioned the love story as a means to engage the audience with the real-life tragedy. A shooting took place on board the Akademik Mstislav Keldysh which aided Cameron in filming the real wreck for the modern scenes, and a reconstruction of the ship was built at Playas de Rosarito, Baja California. Cameron also used scale models and computer-generated imagery to recreate the sinking. At the time†, the picture became the m ost expensive film ever made, costing approximately US$200 million with funding from Paramount Pictures and 20th Century Fox (Butka). â€Å"Principal photography for Titanic began in July 1996 at Dartmouth, Nova Scotia. In September 1996, the production moved to the newly built Fox Baja Studios in Rosarito, Mexico, where a full-scale RMS Titanic had been constructed (Marsh). Special effects played an important role in how the movie filmed. Many critics were skeptical about how Cameron would portray such a disastrous scene, including the deaths of all of the people aboard the ship. Cameron then went on to say that \the people were all computer graphics. The way we did it was, we had people act out all of those individual behaviors in what we call a \motion capture environment.\ So, a steward pouring tea for a lady seated on a deck chair that was all acted out and then that motion file was used to drive and animate those figures. The end result is like you said: We pull back down the full length of Titanic, and you see 350 people all over the decks, doing all those different things. The same technique was used for the sinking when you see hundreds of people on the ship jumping off or rolling down the decks\ (Ebert). Cameron also did not want to cut corners in regards to the props and sets used. In addition to the life-size model of the Titanic, Cameron also had â€Å"construction crews build two huge water tanks. One was 90 foot deep and over 800 foot wide in which the model could slowly sink into 17 million gallons of water fed directly from the Pacific Ocean. The second tank was 30 foot deep. It contained 5 million gallons of water and housed the elegant first class dining saloon and the three story Grand Staircase† (Titanic and Co). One of the most impressive interior sets was the recreation of the famed Grand Staircase the most famous room Titanic contained. Additionally, the Staircase, â€Å"as mentioned by one of the film crew personnel, ended up acting almost as a character in the film, due to it being the location of several pivotal scenes, including the ending scene. Interestingly, the staircase presented in the film is slightly larger than the one on the real ship. The reason for this was because people in 1912 were shorter than they are today. As a result, the staircase was scaled up to make the actors look smaller† (IMDB). For the exterior shots of the ship sinking, the almost â€Å"full-scale ship was placed in a 3 foot deep, 17 million gallon tank and tilted using a crane. For the interior shots of the sinking ship, the sets were enclosed in a 5 million gallon tank and again tilted in the water using a crane. This was the method used for the Grand Staircase. However, to make the destruction of the Grand Staircase more dramatic, Cameron and his team dropped 90,000 gallons of water onto it. Because the Staircase would be destroyed, there would be only one attempt to get it right. Unexpectedly, the massive volume of water ripped the Staircase from its steel-reinforced foundations, collapsing certain sections of it† (IMDB). This destruction of the stair case was relatively dramatic and saddening to the characters and audience because it had become such a vital work of art in the movie. These stairs were much more than just stairs; they were the place in which Jack fell in love with Rose, the place Rose and Jack embraced in their final kiss in the final scene; a true masterpiece that had become one of the characters, gone in an instant. Roger Ebert became â€Å"film critic of the Chicago Sun-Times in 1967. He is the only film critic with a star on Hollywood Walk of Fame and was named honorary life member of the Directors\ Guild of America. He won the Lifetime Achievement Award of the Screenwriters\ Guild, and honorary degrees from the American Film Institute and the University of Colorado at Boulder† (Ebert). He then went on to interview James Cameron on his success and struggles with the making of the Titanic. The footage of the sunken ship was mainly real footage of the actual sunken Titanic. James Cameron believed that in order for the movie to have a more authentic feel, that he should take actual film himself with his own camera. Cameron wasn\t content to buy footage from documentaries about the search for the Titanic; he shot the film\s undersea footage himself, new for this film: \It\s all our own. I made the dives and operated the camera and we lit it and everything† (Ebert) Cameron then went on to explain the struggles that appeared when creating the interior of the Titanic. â€Å"It\s consistent with what Titanic looks like† Cameron mentioned. â€Å"We couldn\t explore the whole interior of the ship. We could only get a glimpse into some areas. We went down some corridors to the D-deck level and saw a lot of the remaining hand-carved woodwork, the wall-paneling, and the beautiful ornate carved doors. A lot of it is still there. It\s very, very cold, which helps preserve things. There are marine organisms that will eat wood, but in certain areas the wood was covered with white-leaded paint that protected Titanic† (Ebert). As morbid as it sounds, it was important to display the fear and anguish on the faces of the people trapped on and inside the sinking vessel. Even though this was a Romeo and Juliet type of love story, the overwhelming message was to portray the absolute disaster the Titanic was and to show the terror on the faces of those involved. Cameron goes on to say that many died in terror, you know, when you look at the numbers, if you were a third class male on Titanic you stood a 1-in-10 chance of survival. If you were a first class female, it was virtually a 100 percent survival rate. It broke down along lines of gender and class. If you were a first-class male, you stood about a 50-50 chance of survival. And the crew took it hardest.\ Of the 1,500 who died, 600 or 700 of them were crew members. The people who stayed in the dynamo room and the engine room, to keep the lights on so that the evacuation would not become panicked who stayed till the end and missed their opportunity to leave t he ship that\s something you\d see less of today† (Ebert). This just goes to show that Cameron felt very passionate about the way he needed to portray this type of despair in his movie, and in order to do that he needed have the film crew work extremely hard in order to portray that same anguish. \That was our most dangerous work,\ Cameron said. \The stunt team worked for weeks in advance, videotaping each one of those stunts and rehearsing it and showing me the tapes. It was all intensely pre-planned and the set was made about 50 percent out of rubber at that point, all padded up. But there\s always an X-factor. We had 6,000 stunt person days on this film the equivalent of one man doing stunts seven days a week for 16 years. But it was all happening at once. We did have a guy break his leg, which I hated. I don\t think anybody should get hurt for a film. So I decided to do more of it with computer graphics† (Ebert). This made it more apparent that special effects had to be made more in order to keep the cast and crew safe. Therefore, the scene in which the Titanic is actually sinking was almost entirely CGI when the camera was sweeping over the boat in a birds eye view. Cameron goes on to talk about the importance of human nature and how the story of Titanic is iconic not because of the class struggles, but once tragedy strikes, we are all on the same level fighting for survival. Cameron goes on to state that the â€Å"great lesson of Titanic for us, going into the 21st century,\ he said, \ is that the inconceivable can happen. Those people lived in a time of certainty; they felt they had mastered everything mastered nature and mastered themselves. But they had mastered neither. A thousand years from now Titanic will still be one of the great stories. Certainly, there have been greater human tragedies during this century, but there\s something poetically perfect about Titanic, because of the laying low of the wealthy and the beautiful people who thought life would be infinite and perfect for them.\ What would you have done? Anyone seeing this movie, I said, will have to ask them this question: Would I have fought to get on a lifeboat? Would I have pushed a woman or a child out of the way? Or would I have sat down in the lounge and called for a brandy, like Guggenheim, and faced the inevitable with grace† (Ebert)? In conclusion, Titanic taught the general public that the human race is not invincible and that nature does not care whether you are rich or poor, perfect or imperfect, or nothing at all. Through the masterful works of camera angles, visual imagery, editing, and specific scenery, director and writer James Cameron was able to recreate the tragedy of the unsinkable Titanic through the camera lens. Cameron was able to display the struggles of love, life, death, and historical understanding through the eyes of Jack and Rose, and through the magic of filmmaking, teach an incredible lesson that will live on through eternity.

Casting Engine Blocks Automotive Manufacturing Processes Engineering Essay

Casting Engine Blocks Automotive Manufacturing Processes Engineering Essay There are several different types of manufacturing processes to choose from out there and many different alloys that are at ones disposal to be used. Some processes include: sand casting, die casting, and lost-foam casting. In this report, sand and die casting will be discussed with the focus on sand casting. Also, choosing a suitable alloy will be discussed. Is the alloy going to be ferrous or non-ferrous and what qualities does the alloy chosen have, to make it a good choice to use with the manufacturing process is a question to ask oneself. In this case, sand casting has the capability of using any alloy whereas; die casting is generally limited to non-ferrous alloys. Aluminum is a very common alloy to use and it can be used for almost any process. Although, this alloy possesses some qualities that would be desired by most, gray cast iron was decided by us to possess even stronger qualities that led us to choose it for the material used in the design of a cast iron block. Sand cas ting is now and has been for some time one of the most commonly used manufacturing processes and the use of gray cast iron fits very well with this process. The reasons for choosing sand casting as the manufacturing process and gray cast iron as the alloy will be discussed further in the report. Problem Statement: To select a suitable casting process and material that will be as per the requirement of efficient, cost effective and environmentally friendly engine block production. Objectives: To discuss the various casting processes that can be used to manufacture an engine block. To select a suitable alloy for the part. To select a suitable casting process. To justify the above selection. To design the selected process to cast an engine block. To discuss the defects in the casting and challenges to be faced while using the selected process and the methods to overcome these. To discuss the cost consideration and environmental impact of using the selected process. The Identification of Suitable Casting Processes The manufacturing of cast engine blocks out of cast iron involves the consideration of what manufacturing process to use as well as a suitable alloy. The alloy chosen for our company is gray cast iron and the process of selecting this particular alloy will be discussed further in the next section. This section will discuss how our company came to choose sand casting as the manufacturing process by comparing this process with other processes. There are several factors involved in choosing a suitable casting process for manufacturing cast engine blocks. Some of these factors include the type of material that can be used in the casting process, the type of part that can be cast, the finish of the product, the amount of time it takes for the process, and the cost involved. In this section, sand casting will be compared with die casting. Although both are good processes to use, the results vary depending on what process is chosen. There are some similarities between the processes, while there are mostly differences in most aspects of the processes. Selecting a Suitable Alloy An engine block is the main part of an engine which holds all most all the parts of the engine. It should house the internal moving parts, fluids and also withstand the forces and pressure developed during combustion. It should have high strength, wear resistance, good machinability, good vibration absorption capacity, corrosion resistance, low thermal expansion, good thermal conductivity and manufacturability and should have less manufacturing cost. In general, most of the industries use cast iron for manufacturing the engine blocks because of the following reasons: It is cheaper, excellent damping capacity, good wear and high temperature resistant, easily machinable, inexpensive to produce, and can tolerate high pressure and RPM. Other materials which are considered for manufacturing engine blocks are aluminum alloys and magnesium alloys. But, after considering the above factors using cast iron is the feasible option. For choosing the right alloy from cast iron variants, their material properties are compared. Table 1.1 compositions of the different cast irons Name Nominal composition [% by weight] Form and condition Hardness [Brinell scale] Grey cast iron (ASTMA48) C  3.4, Si  1.8,  Mn  0.5 Cast 260 White cast iron C  3.4, Si  0.7, Mn  0.6 Cast (as cast) 450 Malleable iron (ASTM A47) C  2.5, Si  1.0, Mn  0.55 Cast (annealed) 130 Ductile or nodular iron C  3.4, P  0.1, Mn  0.4,Ni  1.0, Mg  0.06 Cast 170 Ductile or nodular iron (ASTM A339) cast (quench tempered) 310 Ni-hard type 2 C  2.7, Si  0.6, Mn  0.5, Ni  4.5, Cr  2.0 Sand-cast 550 Ni-resist type 2 C  3.0, Si  2.0, Mn  1.0, Ni  20.0, Cr  2.5 Cast 140 Table1.2 comparision of the strengths of the cast irons alloys Table 1.3 castability of the different metals. As we need a material which is hard enough, having good strength and good castability, from Table 1.1 we can find gray cast iron having enough and nominal hardness. There are materials which are harder than grey cast iron but as hardness increases material can wear the internal components and will be brittle in nature which is not a preferable property. From Table 1.2 we can observe that elongation is less with good yield strength for gray cast iron which is one of the desirable properties. Both pearlitic and martensitic gray cast irons have less elongation with high yield strength but martensitic gray cast iron has more hardness which is against our requirements and Table 1.3 tells that castability is excellent for gray cast irons compared to other metals and alloys. For desired properties like castability, fluidity, resistance to deformation, relatively low melting point and cost On the whole from the above mentioned tables 1.1, 1.2, 1.3 and above desirable properties gray cast iron matches our requirement. So we finally decide to go for the pearlitic gray cast iron. The Effect of Manufacturing Processes on the Product Sand casting and die casting both consist of the pouring of molten metal into a mold, allowing the metal to cool until it solidifies. The type of mold used in these processes usually varies drastically from one another. Die casting uses the molten metal that gets forced into a mold and is subjected to high pressures so that it solidifies very nicely into the die cavity. Sand casting generally uses silica sand as its material for the mold. Sand is generally chosen as the mold material because of the characteristics that it possesses and the fact that its relatively inexpensive. The strength of the mold is critical in the manufacturing process and using the right type of grains in the sand can improve the strength. A specific type of sand is commonly used for sand casting, and that type is called green molding sand. Green molding sand uses a mixture sand, clay, and water. This mixture provides a moist sand to be present in the mold when the metal is poured into the mold. This moist sand then becomes easily reusable, which contributes to lowering the expenses in the process. Sand casting is an efficient process to use because of the flexibility in what can be done as part of the process. There is no limitation to what material can be used, which means that gray cast iron is available to be used when sand casting engine blocks. There is also no limitation to the type of part that can be cast. The part can also be of any size or shape or weight. Another reason for using sand casting is the minimal costs when compared to other manufacturing process, the amount of time required for production of the parts, and the number of parts required in a production cycle. Sand casting allows for the production of one part at a time if necessary, with no limit to the number of parts to be produced. All costs, including mold material, tooling, and labor costs are relatively low compared to other processes. Although, sand casting has many good qualities that persuade us to use this process, there are a few deficiencies in using the process too. These deficiencies include the finish of the material, porosity, and dimensional tolerance. The dimensional tolerance is much greater than that of other manufacturing processes which causes a greater rate of shrinkage. This shrinkage increases the porosity of the material, which results in a rough surface finish. Die casting is an efficient process to use because more precise results. The die casting process allows for the production of solid, fine parts at a high rate. No additional machining should be necessary on these parts since the dimensional accuracy is so good to begin, with that these parts are ready for use after one cycle of the process. Although the types of materials that can be used are limited, which is mentioned in the next paragraph, experimental results show that gray cast iron is a very workable material for die casting. Even smaller sized parts like pins and fasteners can be casted using die casting, but the smooth surface finish and precision of the parts allow for them to be put to good use. Similar to sand casting and any other casting process, die casting has its disadvantages too. Generally, only nonferrous materials can be casted using die casting. The materials work very well, but that still limits the resources out there for the process which could potentially cause some problems. Also, since the parts produced are small, this limits the potential uses of the part. Another problem that could arise is that even though the labor costs are very low since the process is mostly run on automated systems; these systems and all other equipment are relatively expensive. This is the one major difference between sand casting and die casting that cannot be ignored. Ways to lower the costs are still being worked on, but there is still some work left to do to bring these costs down a sufficient amount. It takes a long time to produce these parts, but being able to produce a large quantity at a time helps to make up for the long lead time. These deficiencies will be looked at in greater detail in a later section. The Sand Casting Procedure Sand casting Sand casting is one of the oldest techniques of manufacturing. In this form, molten metal is poured into a mould made of sand. When the metal is hardened and cooled, the part is removed. In sand casting, the mold is made of packed sand. Mold preparation In the process, we chose green sand casting as our casting process. The sand mixture consists of sand, clay binder, water and additives. The sand also includes zircon(ZrSiO4), olivine(Mg2SiO4), iron silicate(Fe2SiO4), chromite(FeCr2O4). Zircon, olivine and iron silicate have low thermal expansion, and chromite has high heat transfer. During the process, all the ingredients are mixed together and the sand should be moist and not dry. Figure 1. Green Sand Casting Mold Sand casting procedure During the process, patterns and cores are made; sand is thoroughly mixed and then formed about the patterns as per our need. The patterns are removed and the two halves of the molds are put together and are thus ready for pouring the molten metal. The preheated metal is then poured slowly into the mold until the mold is full. The part is then cooled and after the part solidifies thoroughly, the sand mold is removed by striking the part. Lastly, we machine the casting to give it its final shape. Defects Sand castings have many defects such as inclusion, shrinkage, air holes, sand holes, cold shut and cracks. In this procedure, the granule shape, granule size and collapsibility of sand mold effect sand mold casting. Quality inspection Quality inspection of sand casting can be done by sharp impact test, x-ray inspection, pressure test, magnaflux inspection and ultrasonic test. Whereas, to inspect the casting in the foundry itself; visual inspection, dimensional inspection, chemical component inspection and testing to figure out the physical properties by doing the hardness or tensile strength test are commonly used. Casting products and mass production The sand used in making the mold can be used again and again(reclaimed), thus the green sand casting process is cheap and widely used compared to other casting process. Due to this mass production of this process in a cost effective manner is possible. CASTING DEFECTS Some of the possible defect that may arise during the sand casting process Shrinkage defects: These defects mainly occur when feed metal is not available to compensate the shrinkage as the metal solidifies. These defects can be avoided by providing proper gates, vents and risers in the mold. Gas porosity: They are formed as bubbles on the casting after it is cooled. This is due to the presence of large amounts of dissolved gas in the molten metal. To prevent this, the metal is melted in vacuum or in the presence of specific low solubility gases such as argon or carbon dioxide. To minimize gas solubility, the super heat temperature can be kept low. Misruns and cold shuts: They are the empty cavities in solidified metal, due to the lack of fluidity, narrow cross sections, back pressure and turbulence. These are rectified by reducing the pouring temperature, adding sprue and proper gates. Metal penetration: This is the presence of rough surface finish because of the liquid metal penetrating the sand mould. This penetration is due to high pouring temperatures. Lowering the pouring temperature will avoid this phenomenon. Hot Spots: They are formed on the surface that is very hard because of the quick cooling compared to the surroundings. Changing chemical composition and providing proper cooling methods like using chills, these can be avoided. Inclusions: These are metal impurities generally oxides, sulfides, nitrides and carbides formed from the material that is eroded from furnace or impurities present in the mold. These inclusions can be reduced by using ceramic filters or melting the metal in vacuum Hot tears: Also called as hot cracking, these are the failures in the casting that are formed while cast metal starts cooling because of the weak strength of the metal when it is hot and the internal stresses. These can be prevented by proper mold design. Mold erosion: Erosion of the mold sand occurs while filling molten metal into the mold, caused due to sand having less binding strength or high pouring velocity of metal. This can be avoided by redesigning the gating system or by using large runners. Identifying challenges in the process and how they are being addressed An engine block has a very complex geometry. The engine block has internal recesses for the coolant, i.e., water to circulate and the cylinders for the piston to reciprocate. So casting such an intricate shape is always challenging. First, the pattern for making the mold must be very carefully designed because the quality of our casting is as good as the quality of our pattern. For such a complex machined part, we must carefully monitor the cooling of the casting; as such a complex part is bound to cool in an uneven manner. We all know that the major problem concerned with sand casting is the poor surface finish, but in an engine block the only important surface is the cylinder where the piston will reciprocate and it is not important for the cooling water to flow through highly machined surfaces. In sand casting, the surface finish can be substantially improved by using finer sands and we are adding zircon to the sand which will result in a better surface finish. Another challenge in sand casting an engine block is the pouring of the molten metal. Since an engine block is huge and has a complicated geometry, the pouring rate of the metal should be carefully monitored. We should not pour it at such a slow rate that the metal solidifies in the pouring vessel itself and it should not be so fast that molten metal could not reach some regions resulting in voids. In fact, the metal should not be poured. It should be pumped against the gravity so as to avoid gas entrapment. As said earlier, an engine block, due to its geometric complexity will tend to cool irregularly. So the risers should be properly placed to take into account this irregular cooling. Addressing the cost consideration The cost associated with sand casting can be divided into three broad categories: Material cost, Production cost and Tooling cost. Material cost As the name suggests, material cost includes the cost of all the materials used in the sand casting process. These materials include the metal, the mold sand and the core sand. The cost of the metal will depend on a number of factors such as cost of the alloy, purity of the alloy and the castability of the alloy. For more pure alloys, the cost will be higher. For alloys with lower castability, additional metal will be required in order to fill the flow channels and the feed heads to assure a good casting, so in such cases, the cost will be higher. The cost of the mold sand and the core sand will depend on the shape and size of the mold and the core respectively. In this case, since our part is an engine block, due to its size and geometric complexity, the cost is bound to be high. Production Cost Again as the name suggests, production cost will include the cost of all the operations that will take place during the process of sand casting. These will include core making, mold making, pouring, and cleaning. The addition of cores to the casting will increase its cost because it will slow the process down. An engine block, a very complicated part, will definitely have cores which will increase the overall production cost by slowing down the production. Pouring and cleaning costs are determined by the size and weight of the casting. So these will be high for an engine block as it is a big and heavy component, and the mold will take longer to fill and the cast block will take longer to be cleaned. Tooling Cost Tooling cost is the cost associated with the tools used during the sand casting process. These include the patterns used to make the molds and the core-boxes to make the cores. Since an engine block is huge and geometrically complicated, tooling cost will be high. Also, since we are designing for mass production, the patterns as well as the core-boxes will have to be used more frequently. The constant use of the tool will result in the wearing down of the tool at a high rate, which in turn will increase the overall cost as the tool will have to be replaced. A solution to this problem will be to use patterns and core-boxes of a better quality material, but again the cost will be high. Environmental Impact of using Sand Casting: Foundries are generally regarded as being dirty and unfavorable to the environment. The primary issues being faced by the casting industry are the excessive volumes of by-products that are to be sent to landfills, and the Hazardous Air Pollutants (HAPs) which are released during the process. Of all the by-products generated by volume, sand is the largest. Even in processes which involve a high level of sand recovery, some amount of new sand is always required to maintain the optimum quality of sand in the system. This in turn will result in loss of sand from the system. After its use, the sand is either sent to a landfill for disposal, resulting in soil pollution, or it is reclaimed off-site. Not all foundry sands are considered hazardous, especially the ones from ferrous foundries, which pass the TCLP (Toxic Characteristic Leaching Procedure), which, after use can be sent to unlined landfills for disposal. Some non-ferrous sands on the other hand contain high levels of metal because they have to be sent to secured landfills and not the unlined ones. Chemical binders inwaste sand can become a crucial issue if resin-coated sands are wasted in large volumes before the pouring stage as most of the binder in the mold is burnt off during the pouring stage. Hence, the binder level should be carefully monitored so as to prevent it from reaching unacceptable levels over a period of many reclamation cycles. The second largest by-product by volume in the sand casting process is the baghouse dust. It is typically formed when the sand is reclaimed multiple times, which results in the sand grains breaking down to dust particles. Not only will it affect the quality of the casting, but it will also result in health issues such as silicosis. Slag is yet another by-product which is formed during the sand casting process. When flux is added to the molten metal to remove impurities, it reacts with the impurities to form slag which floats to the surface and is to be removed before pouring the metal. The slag so formed has a glass like appearance and is not really hazardous as it can be easily disposed of in unlined landfills. Apart from these solid wastes, there is also a substantial amount of gaseous waste (emissions) produced during the sand casting process. These include benzene, carbon monoxide, hydrogen sulphide, sulphur dioxide, phenols, nitrous oxide and other HAPs. Of all the pollutants, benzene is the most emitted. Conclusion In many ways the job of an engineer is not simple, because to choose between one material or one process over another is never easy. There is no process or material which can be considered as perfect. Each process has its advantages and disadvantages. An engineers job is to find an optimum solution so that the huge amount of investment in this industry is justified. In this project we, as engineers have done a similar job. We have selected sand casting for manufacturing the engine blocks and have justified our decision by discussing various aspects, both good as well as bad, of the selected process.