Parasitic Wasps Essays - Health, Nutrition, Biomolecules, Biology

Parasitic Wasps Malaria is one of the most prevalent and dangerous diseases known to man. It has existed for centuries and affects a myriad of people in the tropical region. Even today, with our newly discovered treatments for many of the tropical diseases, over 10% of the people that are infected with malaria each year and do not receive proper treatment die. In Africa alone, over 1 million children die each year because of malaria and new cases are reported frequently. Malaria is very dangerous and harmful to man. However, the protozoan that causes malaria has existed since man came into being. Fossils of mosquitoes that are 30 million years old contain the vector for malaria. After written history, many civilisations have known about malaria. The Greek physician Hippocrates described the symptoms of malaria in the 5th Century BC The name malaria is derived from the Italian words, mal and aria, meaning "bad air", because people of earlier times believed that the disease was caused by polluted air near swaps and wetlands in Europe. The scientific identification of malaria was not found until 1880. The French army physician, Charles Laveran, while stationed in Algeria, noticed strange shapes of red blood cells in certain patients and identified the disease scientifically and linked to a certain protozoan. Although the disease had been identified, it was not until 1897, when British army physician, Ronald Ross studied birds and discovered that the malarial protozoan was transmitted through mosquitoes. Soon after, two Italian scientists noted that mosquitoes spread malaria to humans as well. Many attempts have been made to try to eradicate the disease. As early as 7 AD, in Rome, swamps were drained to try to prevent the "bad air" from reaching nearby cities. Recently, in the 1950's and 1960's, about 25 years after the development of DDT, the United Nations World Health Organisation tried to wipe out the disease through the use of DDT. Although, the number of cases was reduces in many areas, they started again. Scientists today believe that malaria can never be eradicated due to the fact that the protozoan can manipulate easily and become resistant to a drug that is overused. The mosquitoes that spread malaria are also becoming resistant to insecticides. Malaria can be treated on an individual basis and treatments and medicines can be used. To understand these treatments however, one must understand what happens to a malarial protozoan. The disease, malaria, is cause by the protozoan, Plasmodium, which lives in tropical regions all around the world. There are only four species of this protozoan that cause malaria in humans, Plasmodium ovale, Plasmodium vivax, Plasmodium malariae, and Plasmodium falciparum. These protozoans are spread from infected to healthy people through the bite of the Anopheles mosquito, blood transfusions, or through hypodermic injections. This makes malaria one of the most easily communicable diseases in the world. 1.Sporozoites in salivary gland. 2.Ocysts in stomach wall. 3.Male and female gametocytes. 4.Liver phase. 5.Release of merozoites from liver. These enter red cells where both sexual and asexual cycles continue. Malaria is spread only through the females of the 60 different types of the Anopheles mosquito, as the males do not feed on blood. The symptoms of this disease are many, however a physician must be consulted to avoid risk to a person. To treat malaria, many drugs are used today. Forms of these drugs date back to the 1500's and 1600's. Physicians diagnose malaria by identifying Plasmodia in a patient's body. Once identified, malaria can be treated with chloroquine and primaquine. Since some forms of Plasmodia falciparum have become resistant to these, quinine, mefloquine, or halofautrine are used. Almost all of the cases of malaria can be treated if done in the proper way. However, to suffer the pain and illness of malaria, people can use many preventive measures. All swampy areas must be avoided as well as tropical water that may be contaminated or local food. People should just protect themselves from mosquitoes and risk of infection will be tremendously lowered. This can be done by impregnated bednets. These involve surrounding the bed with a curtain that is sprayed with certain compounds. These are normally pyrethroids or organophosphates, which create an effective barrier between the mosquito and its blood meal. Alternative 'barrier' methods are insect repellents. These are certain chemicals that that when applied to the skin as a spray or lotion is quite effective at deterring the mosquito from landing on a person in order to feed. Other methods of controlling malaria are the use of insecticides and vaccines. Insecticides are chemicals such as

Health Safety and Security Essays

Health Safety and Security Essays Health Safety and Security Paper Health Safety and Security Paper The Management of Health and Safety at Work Act (amended 1999) The Management of Health and Safety at Work Regulations 1999 clarify in more general terms what employers are required to do to manage health and safety. If there is falls or injuries in the workplace it highlights the hazards and protects the employee against discrimination in the workplace. Exposure to hazardous agents such as dust, fumes, noise, vibration, radiation or harmful micro-organisms must be eliminated or adequately controlled. All work equipment must meet essential safety requirements and safe systems of work must be established. Risks from work with Display Screen Equipment must be assessed and controlled, appropriate personal protective clothing and/or equipment should be provided free of charge. It also An employer’s main duty is to be aware of the risks imposed upon its personnel, visitors and themselves by the working operations by assessing the risks and asking questions like; what are the risks, how bad are they and what do we do to reduce them. All employers have a duty to ensure, so far as is reasonably practicable, the health, safety and welfare of their employees. They also have a duty to protect non-employees from risks arising out of their work activities. Employers must take and give effect to adequate arrangements for the effective planning, organisation, control, monitoring and review of protective and preventive measures. Employees must take reasonable care of their own health and safety and that of others who may be affected by what they do or do not do; co-operate with their employer and others (eg.  contractors on site) in meeting health and safety requirements; report any shortcomings in health and safety arrangements (consistent with their knowledge and training); and not interfere with or misuse anything provided to assure health, safety or welfare at work. The Control of Substances Hazardous to Health (COSHH) Regulations (2002) COSHH is the law that requires employers to control substances that are hazardous to health. Most businesses use substances, or products that are mixtures of substances. Some processes create substances. COSHH covers substances that are hazardous to health. Substances can take many forms -Chemicals, products containing chemicals, fumes, dusts, vapours, mists, nanotechnology ,gases and asphyxiating gases and biological agents (germs). If the packaging has any of the hazard symbols[1] then it is classed as a hazardous substance. Sometimes substances are easily recognised as harmful. Common substances such as paint, bleach or dust from natural materials may also be harmful. Employees or service users may breath in the harmful fumes, dust gas or mist. They may have skin contact which could irritate and break out into a rash or infection. By injection into the skin by a sharp unsantized needle if not kept in a locked trolley and also swallowing. T prevent exposure to harmful chemicals may procedures are carried out e. g. using control equipment, eg total enclosure, partial enclosure, controlling procedures, e. g. ways of working, supervision and training to reduce exposure, maintenance, examination and testing of control measures; worker behaviour, making sure employees follow the control measures. Employers are responsible for providing, replacing and paying for personal protective equipment. PPE should be used when all other measures are inadequate to control exposure. It protects only the wearer, while being worn, this includes respirators[1] ,Protective gloves[2] ,Protective clothing Protective footwear, Eye protection. Data Protection Act The Data Protection act controls how your personal information is given out my health professionals, organisations and by the government. It is also set to protect your privacy. There is also a list of Data Principles which they have to follow on how they give out your personal information used fairly and lawfully, used for limited, specifically stated purposes, used in a way that is adequate, relevant and not excessive, accurate, kept for no longer than is absolutely necessary, handled according to people’s data protection rights, kept safe and secure, not transferred outside the UK without adequate protection. If information is given out carelessly this can result in discrimination or abuse in both a workplace and care home setting. For example if a care worker was to find out a service user was of a certain ethnic background or religion they may be mistreated. This mistreatment can include not being fed, bathed or talked to in an appropriate manner. Care homes protect the service users personal information by not giving out any personal information in person and also by phone. They are restricted to what information they give out, they are only allowed to give answers such as â€Å"they are comfortable†. The Manual Handling Operations Regulations Aim to reduce the incidence and prevalence of musculoskeletal disorders place duties upon employers in respect of their own employees. Identical duties are placed on the self-employed in respect of their own safety. The Regulations do not impose duties on employers in relation to other persons, eg voluntary workers transporting patients for the health services. The employers duty is to avoid Manual Handling as far as reasonably practicable if there is a possibility of injury. If this cannot be done then they must reduce the risk of injury as far as reasonably practicable. If an employee is complaining of discomfort, any changes to work to avoid or reduce manual handling must be monitored to check they are having a positive effect. However, if they are not working satisfactorily, alternatives must be considered. Incorrect use of manual handling is one of the most common causes of injury at work. There are many risks and hazardous to the service user and care worker associated with MHOR. Restrictions on posture, bumpy, obstructed or slippery floors, variations in floor levels, hot/cold/humid conditions, gusts of wind or other strong air movements, poor lighting conditions, restrictions on movements from clothes or personal protective equipment (PPE) Before MHOR there should be a general risk assessment to ensure both persons safety. A risk assessment is about identifying and taking sensible and proportionate measures to control the risks in a workplace and nursing home etc. Employees and their representatives know first-hand what the risks in the workplace are. They can probably offer practical solutions to controlling them. Though employees have duties too. They should follow systems of work in place for their safety, use equipment provided for their safety properly cooperate with their employer on health and safety matters, inform their employer if they identify hazardous handling activities, take care to make sure their activities do not put others at risk. The most common injuries that carers experience are back injuries, which affect more than a million people in the UK. Hurting their back can limit their movement and how much they can care for someone. Lifting someone incorrectly can also damage fragile skin, cause shoulder and neck injuries, increase existing breathing difficulties, or cause bruising or cuts. Reporting of Injuries,Diseases and Dangerous Occurences Regulations (RIDDOR) 1997 RIDDOR (NI) ’97 requires the reporting of work-related accidents, diseases and dangerous occurrences. It applies to all work activities, but not to all incidents. It places a legal duty on the employers, self-employed and owner of the premises. There are many reportable dangerous occurrences accidental release of a biological agent likely to cause severe human illness, malfunction of breathing apparatus while in use or during testing immediately before use, acute illness requiring medical treatment, or loss of consciousness arising from absorption of any substance by inhalation, ingestion or through the skin; acute illness requiring medical treatment where there is a reason to believe that this resulted from exposure to a biological agent or toxins or infected material. The regulations require responsible persons to report deaths at work, major injuries caused by accidents at work, injuries to persons not at work that require hospital treatment, injuries arising from accidents in hospitals, and dangerous occurrences. Responsible persons are generally employers but also include various managers and occupiers of premises. Care Home Regulations An employer should report the death of any service user, including the circumstances of his/her death;the outbreak in the care home of any infectious disease which in the opinion of any registered medical practitioner attending persons in the care home is sufficiently serious to be so notified; any serious injury to a service user; serious illness of a service user at a care home at which nursing is not provided; any event in the care home which adversely affects the well-being or safety of any service user; any theft, burglary or accident in the care home; any allegation of misconduct by the registered person or any person who works at the care home.

Free Trade Essay Example | Topics and Well Written Essays - 250 words

Free Trade - Essay Example e with the organizations of developed world since they have access to better technological tools that allow them to produce goods and services in much cost effective manner. Free trade discourages a nation to attain self-sufficiency since the nation only produces those goods and services that they can produce in a much effective and efficient manner as compared to producers of other nations. Free trade is only healthy when both the importing and exporting countries have not levied trade restrictions. 2. Government may restrict free trade with the use of tariffs which refers to the imposition of taxes on the amount of goods that can be imported. Government can restrict import by imposing quotas which are restrictions on the quantity of a particular good or service that can be imported. They may provide subsidies such as tax benefits to exporters. The government may adopt these policies for several economic and political reasons. They may do so in order to motivate industries to develop and produce locally and this in turn will benefit the local economy (Jones, 2001). They may impose these restrictions to provide support to industries that have just been set up within a nation. They may do so in order to correct the issue of balance of payment which may be created due to excess of imports over

Business Ethics and Virtue Ethics Assignment Example | Topics and Well Written Essays - 500 words

Business Ethics and Virtue Ethics - Assignment Example First, only name of the writer is mentioned below the topic; no credentials about the author are provided. In addition to that, glossy and colorful advertisements are appearing with the article, authenticating the work has not undergone the process of peer-reviewed articles. In addition to that, the content of the article is based on the facts and some opinions as well. This article is a piece of non-scholarly material. Although the author name, Jona Than Dee, is provided. But, no other important pieces of information such as his qualification, experience, expertise, affiliation and academic background, are provided. In addition to that, to qualify for a scholarly article, a well-known publisher must be there to authenticate the content nature and quality of the article. This article looks less logical and more subjective, showing the personal understanding of the author. Moreover, the author has not provided the sources of information; he has filled the entire article of at least more than 2000 words without quoting any secondary source! 4) â€Å"75 years of lessons learned: chief executive officer values and corporate social responsibility.† Carol-Ann Tetrault Sirsly. Journal of Management History. Bradford: 2009. Vol. 15, Iss. 1; p. 78 This article represents a depiction of scholarly material. Journal of Management History is an authentic journal in the field of management and processes every article under the peer-review mechanism. And, Emerald Group Publishing Limited is an authentic publisher. This piece is revised material of the paper presented at the 2007 Academy of Management meeting in Philadelphia. A list of references has been attached at the end of the article, showing the validity and reliability of the article. And, the content is balanced with appropriate facts and opinions. 5) â€Å"Corporation communication, ethics, and operational identity: a case study of Benetton.† Janet L Borgerson,

Labour Law in Canada Research Paper Example | Topics and Well Written Essays - 1000 words

Labour Law in Canada - Research Paper Example Additionally, the wrangles and inadequacies that the firm experiences, especially communication, might have emanated from the absence of proper training. Therefore, the employer and the executive ought to institute adequate policies, which would impart adequate knowledge to the staff. This is via shunning utilization of its own staff to train fellow peers regardless of the post that they hold. Since, these members of staff also require training due to their evidenced misconduct while dealing with their peers, for illustration, Williams. Prior to any terminations, the firm via its executive ought to have prepared notices meant to inform the staffs regarding the core reasons that prompted their intended discontinuations (Karabegovic 2011). This would be according to the dates stipulated by labour laws, which stipulates when one started working and the duration or alternatively using termination pay option. What are the critical issues to be decided by the board? Employees’ mode of termination was pathetic coupled with rudeness especially by the executives. For example, Williams who rather than sending notices to the staffs or summoning them before utilized the telephone in executing the advocated termination by the employer. The company did not even bother to address the workers regarding reasons, which prompted their terminations. In addition, the issue of meagre wages did demoralize the workers (Karabegovic 2011). Consequently, the employer should improve the staff’s both physical and invisible environment, which will enhance their morale and productivity. These encompass the Store 58’s floor and resolving of the evident wrangles amid the... What are the critical issues to be decided by the board? Employees’ mode of termination was pathetic coupled with rudeness especially by the executives. For example, Williams who rather than sending notices to the staffs or summoning them before utilized the telephone in executing the advocated termination by the employer. The company did not even bother to address the workers regarding reasons, which prompted their terminations. In addition, the issue of meagre wages did demoralize the workers (Karabegović 2011). Consequently, the employer should improve the staff’s both physical and invisible environment, which will enhance their morale and productivity. These encompass the Store 58’s floor and resolving of the evident wrangles amid the staffs. Which party bears the burden of proof and why? In this situation, the employer via the managerial body bears the burden of proof due to their witnessed misconduct. This is especially the manner in which the executive contacted terminations coupled with their rude remarks especially towards the employees (Karabegović 2011).

Orr-sommerfeld Stability Analysis of Two-fluid Couette Flow

Orr-sommerfeld Stability Analysis of Two-fluid Couette Flow ORR-SOMMERFELD STABILITY ANALYSIS OF TWO-FLUID COUETTE FLOW WITH SURFACTANT V.P.T.N.C.Srikanth BOJJA1* , Maria FERNANDINO1, Roar SKARTLIEN2 ABSTRACT In the present work, the surfactant induced instability of a sheared two fluid system is examined. The linear stability analysis of two-fluid couette system with an amphiphilic surfactant is carried out by developing Orr-Sommerfeld type stability equations along with surfactant transport equation and the system of ordinary differential equations are solved by Chebyshev Collocation method[1,2]. Linear stability analysis reveals that the surfactant either induces Marangoni instability or significantly reduces the rate at which small perturbations decay. Keywords:Linear stability, Orr-Sommerfeld, Marangoni mode, Amphiphilic surfactant. NOMENCLATURE A complete list of symbols used, with dimensions, is given. Greek Symbols Growth rate Surfactant concentration Mass density, [kg/m3]. Dynamic viscosity, [kg/m.s]. Height of perturbed inteface Surface tension Wave number ,Stream functions Latin Symbols Capillary number Marangoni number Number of Collocation pints Reynolds number Plate/Wall velocity Complex wave spped Width of fluid layer Amplitude of Pressure disturbance Amplitude of surfactant concentration disturbance Amplitude of interface perturbation Viscosity ratio Depth ratio Shear of basic velocity Velocity, [m/s]. Sub/superscripts Index i. Index j. Perturbed quantities Base state quantities INTRODUCTION Two layer channel flows and flows with and without surfactants have been given considerable importance because of its numerous industrial applications. Oil recovery[3], lubricated pipelining[4], liquid coating processes[5] are typical industrial situations where Two layer channel flows are often seen. Surfactants also have wide range of industrial applications for example in enhanced oil recovery[6]. Using Perturbation analysis, the primary instability of the two-layer plane Couette–Poiseuille flow was studied by Yih[7] and his studies revealed that even at small Reynolds numbers, the interface is susceptible to long-wave instability associated with viscosity stratification. Yiantsios Higgins[8] later extended this study for small to large values of wavenumber and confirmed the existence of the shear mode instability. Boomkamp Miesen[9] came up with the method of an energy budget for studying instabilities in parallel two-layer flows, where energy is supplied from the primary flow to the perturbed flow and instability appears at sufficiently long wave numbers through the increase of kinetic energy of an infinitesimal disturbance with time. In the presence of surfactant at the sheared interface, Frenkel Halpern[10,11] discovered that even in the stokes flow limit, the interface is unstable as the surfactant induces Marangoni instability, which was later confirmed by Blyt h Pozrikidis[12]. In the case of Stokes flow, they identified two normal modes, the Yih mode due to viscosity stratification inducing a jump in the interfacial shear, and the Marangoni mode associated with the presence of the surfactant. In contrast, at finite Reynolds numbers, infinite number of normal modes are possible and by parameter continuation with respect to the Reynolds number the most dangerous Yih and Marangoni modes can be identified. In this article, the effect of an insoluble surfactant on the stability of two-layer couette channel flow is studied in detail for low to moderate values of the Reynolds number. To isolate the Marangoni effect, gravity was suppressed in this problem and this was done by considering equal density fluids. Linear stability analysis was carried out by formulating Orr–Sommerfeld boundary value problem, which was solved numerically using Chebyshev collocation method[1][2] for all wavenumbers. Both Marangoni mode and Shear mode are detected and utmost focus is given to Marangoni mode as Shear mode is always stable at moderate to long wavenumbers under the influence of inertia. The rest of the paper is organized as follows. In  § Model description, the governing equations for the system in question are laid out, Normal mode analysis of the physical system is carried out, Orr–Sommerfeld boundary value problem is formulated. General description of Chebyshev collocation method and detailed description of numerical simulation of Orr–Sommerfeld boundary value problem by Chebyshev collocation method and validation of numerical method with literature data is given in  § Numerical method. Detailed discussion of results done in  § Results. The concluding remarks and outlook for further-work in  § Conclusions. Finally acknowledgements in and  §Acknowledgemnts. Model description Consider two super-imposed immiscible liquid layers between two infinite parallel plates located at, as in Fig. 1. Let the basic flow be driven only by steady motion of plates. It is well known that the basic ‘‘Couette’’ velocity profiles are steady and vary only in the span-wise direction and in the basic state, the unperturbed interface between the liquids is flat and is located at. The gravity is suppressed in this problem by considering equal densities in order to investigate the effects of surfactant and inertia on the stability of the system under consideration. The subscripts 1 and 2 refer to the lower or upper fluid, respectively and channel walls move in the horizontal direction, x, with velocities and. The interface is occupied by an insoluble surfactant with surface concentration which is only convected and diffused over the interface, but not into the bulk of the fluids thus locally changing the surface tension . Governing equations The mass and momentum conservation equations governing the two-layer system are , (1) Where subscript represents lower and upper liquid layers respectively. Here , Figure 1: Schematic sketch of Couette-Poiseuille flow with surfactant laden interface. The perturbed interface is shown as sinusoidal curve. is the concentration of insoluble surfactant. The associated boundary conditions for the system are no slip and no penetration boundary conditions at the walls. ,at and ,at The associated interface conditions are continuity of velocity, tangential stress and normal stress. Continuity of velocity at the interface , at The tangential and normal stress conditions at the interface are given by (2) Where are stress tensors, is unit normal, is unit tangent and Kinematic interfacial condition is The surfactant transport equation[13] at the interface is given by (3) Where is surface molecular diffusivity of surfactant. is usually negligible and neglected in this case. We introduce dimension less variables as follows , , , , The dimensionless variables in base state for the couette flow with flat interface and uniform surfactant concentration are given by , ( ) and , () Where is shear of basic velocity at interface and is given by We consider the perturbed state with small deviation from the base state: ,,,, Now we represent disturbance velocity in disturbance stream-functions and such that ,,, Performing normal mode analysis by substituting Where is wave number of the disturbance, and are constants, and is the complex wave speed. Linearizing the kinematic boundary condition yields . Linerarizing the dimensionless x and y-components of Navier-Stokes equation (2) followed by subtraction from the corresponding base state equations and elimination of pressure terms, yields two 4th order Orr-Sommerfield ODEs in stream-functions, one for each fluid. (4a) (4b) Where is the Reynolds number and . (when,) Boundary conditions at wall in terms of stream-functions are (5a) (5b) Continuity of velocity at interface gives , (5c) Linearization of normal stress condition gives (5d) Linearization of surfactant transport equation gives Linearization of tangential stress balance condition gives Where is the Marangoni number. By substituting the value of from linearized surfactant transport equation in linearized tangential stress balance condition gives (5e) For each value of Eqs. (4),(5) forms a eigen value problem, which was numerically solved using chebyshev collocation method[1,2] and QZ algorithm for determining the complex phase velocity . Numerical method The two Orr-Sommerfield equations eqs. (4) along with eight boundary conditions eqs. (5) are solved numerically using Pseudo-spectral Chebyshev collocation method[1,2]. To implement the Chebyshev method, we transformed each of the two fluid domains into standard Chebyshev domain that is Fluid 1 domain is mapped to and Fluid 2 domain is mapped to by substituting and respectively. Next, we represent each stream function as truncated summation of orthogonal Chebyshev polynomials by setting. and(6) Where and are unknown Chebyshev coefficients and N is the number of Cheyshev collation points in each domain. Upon substituting eq. (6) in eq. (4) and projecting them on to arbitrary orthogonal functions and respectively by taking the Chebyshev inner product, . these two Chebyshev inner products forms N-3 equations each summing up to 2N-6 equations and N+1 coefficients in and N+1 coefficients . 2N-6 equations along with 8 boundary conditions obtained by substituting eq. (6) in eq. (5) and 2N+2 coefficients forms a linear system Where, and,are square matrices of size 2N+2. This generalized eigen value problem was solved by QZ algorithm to obtain and subsequently growth rate, .We used, above which the eigen values are independent of number of collocation points. The accuracy of the Numerical method is checked by comparing current results with published literature[10] for the Two layer couette flow with an insoluble surfactant in stokes flow limit. To make this comparison, growth rates are calculated by muting the inertial terms by settingin the our code and with same parameters as in Halpern’s[10] Fig 2a and Fig 2b, where growth rates are predicted by long-wave evolution equation. Fig xxx shows excellent agreement between two numerical procedures. Figure 2: Dispersion curves for the most (a)Unstable Figure 3: Dispersion curve for the (solid line), (dashed line), at, ,, RESULTS and discussions Blyth and Pozrikidis[14] observed that in the Stoke’s flow limit, there exists two modes that govern the stability of a two-layer couette flow system with surfactant: the Marangoni mode and the Yih mode associated with surfactant and the clean liquid-liquid interface respectively. But on the other hand, in flows with inertia, there exists more than two normal modes. From Fig. 3, the broken line corresponding to is above the solid line, which corresponds to , it is evident that the surfactant in the presence of inertia has significantly reduced the rate at which small perturbations decay. Earlier stability analysis for stoke flow in presence of surfactant opens up a range of unstable wave numbers extending from zero up to the critical wavenumber .The neutral stability curve Fig. 4 for values (,, and ) is in accordance with the earlier stokes flow stability analysis and in addition at , a second small window of stable wave numbers appears to form an island of stable modes, wit h the island tip located at . In Fig. 5 we plot the growth rate of the Marangoni mode against the Reynolds number, up to and beyond, for , corresponding to the stable island tip. At, linear stability for Stokes flow predicts the growth rate, for the Marangoni mode. The present results confirms that the Marangoni mode at marks the inauguration of the lower stable loop. In Fig. 6 for a fixed Reynolds number , we show the dependence of the growth rates of the Marangoni mode on the wave number. The close-up near , presented in Fig. 6(b), shows that the Marangoni mode has negative growth rate for small band of wave numbers ranging from and has positive growth rate thereafter up-to , beyond which the Marangoni mode is stable again. These results clearly demonstrate the crucial role of the surfactant, which either provokes instability or significantly lowers the rate of decay of infinitesimal perturbations. Figure 4: Neutral stability curves for ,, and Figure 5: Growth rate vs. Reynolds number for the Marangoni mode for, , , , , Figure 6: Dispersion curve for the Marangoni mode (solid line) for,, , ,, (b) Zoom-in of (a) around Figure 7: Neutral stability curves for , , and (a) (b) (c) (d) (e) (f) Further, we investigated the effect of Marangoni number on the stability of the system under consideration via Fig 7(a) and this shows that in the devoid of surfactant that is at there is very small band of wavenumbers where the system is unstable for any Reynolds number. Moreover around the band of unstable wavenumbers is slightly larger than at any arbitrary Re. In presence of surfactant, Fig. 7(b)-7(e) a second small window of stable wave numbers appears to form

Biblical Allusions and Imagery in Steinbecks The Grapes of Wrath :: Grapes Wrath essays

Biblical Allusions and Imagery in Steinbeck's The Grapes of Wrath John Steinbeck always makes it a point to know about his subjects first hand. His stories always have some factual basis behind them. Otherwise, he does not believe that they will be of any value beyond artistic impression. Therefore, most of his novels take place in California, the site of his birth and young life. In preparation for writing his novels, Steinbeck would often travel with people about whom he was going to write. The Grapes of Wrath was no exception to his other works. To prepare for it, he joined migrants in Oklahoma and rode with them to California. When he got to California, he lived with them, joining them in their quest for work. By publishing these experiences and trials of the migrants he achieved an effect that won him the Nobel Prize for literature in 1962. The writing of The Grapes of Wrath coincided with the Great Depression. This time of hardship and struggle for the rest of America gave Steinbeck inspiration for his work. Other peoples' stories of everyday life became issues for Steinbeck. His writings spoke out against those who kept the oppressed in poverty and therefore was branded as a Communist because of his "voice." Although, it did become a bestseller and receive countless awards, his book was banned in many schools and libraries. However, critics never attacked The Grapes of Wrath on the artistic level and they still consider it a beautifully mastered work of art. More than any other American novel, it successfully embodies a contemporary social problem of national scope in an artistically viable expression.1 In The Grapes of Wrath, Steinbeck utilizes Biblical imagery and allusions to illustrate the struggle of the Joad family as a direct parallel with that of the Hebrew people. Steinbeck bolsters the strength of structure and character development in the book through Biblical allusions and imagery. Peter Lisca has noted that the novel reflects the three-part division of the Old Testament exodus account which includes captivity, journey, and the promised land.2 The Joads' story is a direct parallel with that of the Hebrews. Just as the Hebrews were captives of the Pharaoh, the Joads' are captives of their farm. Both make long and arduous journeys until they reach their promised land. Israel is the final destination for the Hebrews and California plays the same role for the Joads. Hunter mentions several of the parallels in the novel. When the Joads embark on their journey, there are twelve members which corresponds to the twelve tribes of Israel who are leaving the old order behind.