Essay On Science Science Essay Topics Science Essay Topic Computer Science Essay
Thursday, October 31, 2019
Consuming Healthy Fresh Green Foods Essay Example | Topics and Well Written Essays - 500 words
Consuming Healthy Fresh Green Foods - Essay Example The function of this essay is about the differences in fresh food and canned food. In my opinion, flavors, health benefits, and costs are the main factors in our decision to consume either fresh food or canned food. I will never forget the taste I experienced one day when I ate fresh vegetables from the garden. This was in stark comparison to the taste of the asparaguses, which were kept in oily water in a can. Besides, I did not know how long the vegetable had been there. The look of the soft, moist vegetable was unappetizing compared to the green color and texture and overall taste of fresh food. The main unique difference between these two types of food is in the flavor. Fresh food has a nice texture and the freshness makes you want to consume even more. Despite this, the vitamins in the vegetable will begin to lessen as soon as the vegetable is picked from the garden and sent onto the consumer. The next comparison between fresh food and canned food is the health benefits involved. Fresh food helps to prevent illness. This is especially true for organic food. Organic food is safe for the human body as it contains more vitamins, calcium, and iron than non-organic food. Organic food is healthier and tastes better than conventional produce. Fresh vegetables are more beneficial than other types of food. Canned fruit and vegetables have the same amount of vitamins as fresh food; however, this should not be consumed too often as canned food has some chemical factors that are not good for your body and will harm your health in the long term. Today, most canned food is available for people who want to have a balanced diet. The price is another huge difference between these two kinds of food. Canned food often entails less cost than fresh food and can be bought throughout the year. Canned food is a lot cheaper than fresh food because not much preparation time has been put in. In many cases, canned food can be very beneficial for families who have busy
Tuesday, October 29, 2019
Lockeââ¬â¢s Second Treatise of Government Essay Example for Free
Lockeââ¬â¢s Second Treatise of Government Essay Introduction In this essay, I would like to discuss Lockeââ¬â¢s Second Treatise of Government section 131. This essay is divided into four parts. In the first part, I would like to interpret what Lockeââ¬â¢s position is developed in section 131 and in the next part, I would like to discuss how Locke supports this position by tracing back to the origin of government. Then in the third part, I would like to point out some flaws in this position by arguing evidences provided by Locke to support his position. The last part of my essay is the conclusion. Lockeââ¬â¢s Position in Section 131 In section 131, Locke explained that the ultimate aim of uniting a society is to protect the security and property of the people and developed the position that the society should never extend its power farther than the common good of citizens because its supreme power is originated from the consent of people. In a word, according to Locke, the society is obligated to secure their property and is limited by the consent of people. In order to prove the limits of the government, Locke traces back to the origin of government: why man is willing to give up his freedom and subject himself to the dominion of a commonwealth instead of staying in the state of nature where he has right to everything. Three Inconveniences in the State of Nature According to Locke, for a rational man, the reason why man is willing to surrender their rights, though man has right to do anything without being affected by the will of others within the law of nature in the state of nature is the uncertainty of his preservation. The enjoyment is unsafe. Because man is partial to his own interest and is lacking awareness of the law of nature ââ¬ËThat being all equal and independent, no one ought to harm another in his life, health, liberty, or possessionsââ¬â¢ (Chapter 2, Section 6) and there are probably continual invasions of others. As a result of this, there are three inconveniences under those circumstances. The first inconvenience is that there are no such established and well-known laws which can be used as the standard to judge what is right and what is wrong so that everyone is uncertain about their future and their property including their security, estate and possession etc. Or if there is a united society, The second one is that there is no popular and indifferent judge to rigidly distinguish between right and wrong by the established law. Everyone can be the judge himself in the state of nature, but they always tend to bias to themselves, their friends and families. The third one is that there is no power to ensure the punishment. In the state of nature, everyone has the right to punish whoever breaks the law of nature. According to Locke, it is executive power. But that may put them in a dangerous situation so that the punishment is hard to be carried out. The origin of the Government According to Locke, due to all these defects in the state of nature, people were thinking about uniting a commonwealth. Surrendering their rights to a sovereign which can use the supreme power to protect them is a remedy. The right of government comes from its subjects, and the government can never override them. Lockeââ¬â¢s Solutions to Restrict the Power of the Government and My argument From my perspective, I think Lockeââ¬â¢s position on the limits of government seems kind of idealistic. The biggest question is how citizens can ensure that after the government gains the supreme power, it does what it is expected to do as original intention. Political power has a character to expand itself. If there is no limit of power of the sovereign, even though he is a man who has a good virtue, it is still uncertain that he governs the society following the law without any extemporary decrees all the time. Hence, Locke provides three solutions to restrict the power of the government. There might be some fIaws in them. I would like discuss all of them below step by step. The first solution that Locke provides is that the government is limited by the law established by the consent of the majority. When the sovereign rules the state, he must obey the laws which made by the majority rather than govern it by his own will. ââ¬Å"And so whoever has the legislative or supreme power of any commonwealth, is bound to govern by established standing laws, promulgated and known to the people, and not by extemporary decreesâ⬠(Chapter 9, Section 131) From my perspective, obviously there is no coercive power to guarantee that the government is run by the law except revolution (I will it discuss in the third point.) Moreover, it is also questionable whether there exists such kind of law which is able to represent the common good indeed. Even in our times when the legal system is more developed than the times when Locke lived, a large number of flaws can be found in our laws. Locke argues that laws can be updated. But no matter how up-to-date the law is, it still cannot cover everyoneââ¬â¢s interest. The universal of controversy cannot be avoided as long as people are in the different situation. Locke himself admitted that when man enters into a society, he gives up his equality ââ¬Å"when they enter into society, give up the equalityâ⬠. (Chapter 9, Section 131) As there are different classes of citizens, they must have some different interests, which make them in different statuses of society. There is no contradiction unless there is no difference among people. Even that we are equal before the law, we cannot be protected by the laws equally. For instance, is a person is too poor to afford a lawyer, when his right is impaired, he cannot protect his right by law means and if a person has not studied laws, his property might be invaded without knowing it. If the inconvenience is caused by the ignorance, there is no distinct difference between the state of nature and the commonwealth. Furthermore, if there are conflicting interests between a person and the government, it will be in a dilemma. In this situation, if the person protects his own interest by law, interests of government will be impaired. And in the long run that may lead to the impairment of interests of moreà people even include the first man who tried to protect his interests by law. Locke may argue that in his second method that he advocates the division of political power and that he divides supreme power into three: legislative, executive and foreign power. What the government has is just executive power. The parliament has right to making law. And the government is run by the law. How can it do beyond the law? Moreover, the legislative power which belongs to citizens is always higher than executive power. It is one of the greatest contributions of Locke that he advocates to make legislative and executive powers apart, but in comparison to three individual powers: legislative, executive powers and judicial review in political system today are employed, like the United State of America, It is not hard to find out the lack of judicial review in Lockeââ¬â¢s theory. Locke only divided legislature and executive branches. It seems that the structure of the government created by Locke is less developed than that of today. Without judicial review, the balance of power is weaker. Even our modern society in which there judicial system exists, the administration tends to gain power from time to time. For example, under the circumstance that judicial review exists, it seems that the strength of the president becomes stronger and stronger in the US. Moreover, Locke thinks that legislature could be formed of not only representatives but also the noble or a single hereditary person who has an executive power. ââ¬Å"Let us suppose then the legislative placed in the concurrence of three distinct persons. 1. A single hereditary person, having the constant, supreme, executive power, and with it the power of convoking and dissolving the other two within certain periods of time. 2. An assembly of hereditary nobility. 3. An assembly of representatives chosen, pro tempore, by the people.â⬠(Chapter 16, Section 213) That weakens the strength of legislative further. Even though those two solutions cannot completely ensure the government is run in the right way, Locke provides the third solution that people can take back their rights that they gave to the government by revolution and transfer rights to another sovereign if the government breaks the law ofà nature. However, another problem may rise. There is the limit of revolution that Locke provides. According to Locke, the revolution could be legimate only carried out by the majority. What if what the government did is just harmful to the interest of the minority? Can the government united with the majority benefit from the minority by abusing their rights? The only thing that they can do is bearing subject themselves under the exploit. I do not think that Locke himself would like to become one of the minority members in that situation. Sometimes the good of the majority is not necessary the good of the minority. That is also an action of beyond the common good. It can be imagined that the consequence of benefit from doing harm to a small group of people is no difference with a political system of tyranny. In conclusion, Locke supports his statement that the government can only do the common good and never override citizens by tracing back the origin of the government. Because of three inconveniences in the state of nature, people are willing to transfer their rights to a government. The right of government comes from the consent of people, so it can never extend farther. And Locke provides three means to limit the power of government. However, I suggest that there might be some difficulties to carry out these measures. There is no such coercive power to compel the government to play its role by laws. Furthermore, there is a doubt if such kind of laws representing the common good existing. And there is no judicial review to decide whether and when actions break the law. The action of revolutions does not working all the time. The rule of revolution Locke provided may be the legitimate basis of putting the minority in the tyranny of the majority. But in any case, Lockeââ¬â¢s theory shows us the end of the society and the idea, the balance of power, and directs us to think about the way to improve the political system and make it more democratic.
Sunday, October 27, 2019
Effects of Transition on Child Stress
Effects of Transition on Child Stress Using evidence, write an essay showing how stress is influenced at the levels of the individual, family, locality and society. Chose one intervention at one of the levels and say why you think it could be effective in tackling the problem.à This essay looks at how stress is influenced at many levels: individual, family, locality and society, and concentrates on the level of family, to describe an intervention that could be effective in tackling the problem. As Finlay et al. (2005; p. 141), stress is something that everybody experiences at some point in their life, from children to adults, although excessive amounts of stress can be harmful for individuals in terms of their health and longevity. It is therefore important that the causes of long-term stress be identified and that interventions are utilized in order to minimize the adverse effects of this stress. As Finlay et al. (2005; p. 29-31) point out, however, stress can have many causes, from individual factors, to family concerns, to external factors from the individualââ¬â¢s environment (locality) to societal-level factors, all of which can lead to an individual experiencing stress. This can make it difficult to isolate one intervention that could be effective; the remainder of the essay will, however, describe a case study and will highlight one intervention that might be effective in this case. The particular example that will be used is that of a primary-aged child who is showing signs of stress. The child is manifesting behavioural changes, such as disturbed sleep and mood swings, and is experiencing headaches and loss of appetite, all of which are classic signs of childhood stress (Flinn, 1999). The child is the youngest child of a two-child family, and has just started primary school. His parents both work full-time and they are rarely in the house. The family does not eat together. The childââ¬â¢s older brother is a teenager, and is going through exams at the moment. He himself is also showing signs of stress, and all the spare time the parents have, they spend with their oldest child, helping him cope with his exams. It is clear that the youngest child is being neglected emotionally, at a time when he needs support, having just moved to full-time school. There are many stressors on this child, which can be addressed through some simple interventions, which will be discussed below. A recent study (Turner-Cobb, 2008) shows that, in particular, periods of transition in childhood can be extremely stressful for children. Studies have suggested that stress can be anticipated by children, which can lead to deep anxiety (Primary Report, 2007). As shown by Flinn (1999), untreated stress in childhood can have long-term health effects, such as adverse developmental effects (McEwen, 2008) and increased mortality (McEwen, 2003). In addition, childhood stress can lead to social problems, such as poor familial relationships, and behavioural disorders as a result of this (McEwen, 2003; Alfven et al., 2008; Flinn, 1995). As Flinn and England (1997) show, supported by Bauer and Boyce (2004), these social problems can then lead, in later life, to socio-economic problems caused by long-term health concerns. As (Finlay et al., 2005; p.64) state, ââ¬Å"Family relationships have both a positive and a negative effect on health behaviours and healthâ⬠. As suggested, the lack of ââ¬Ëfamily mealsââ¬â¢, where the whole family sits down to eat can disrupt the parent-children relationship, and can lead to stress being put on the children, who feel they do not have a regular point of contact with their parent(s), breaking the facility for communication with their parent(s) (Finlay et al., 2005; p.64). This certainly seems to be the case here, where the parents work full-time and have little spare time to spend ââ¬Ëquality timeââ¬â¢ with their child. As (Finlay et al., 2005; p.70) suggest, the changing roles within families have put stress on the family, with both parents working meaning that the children are less likely to see their parents for extended periods of time, leading to a greater need for independence at an earlier age and, also, potentially leading to poor health beha viours in the children and to higher levels of stress in these children. What can be done, what intervention can be suggested, to help this child? Given that the child is young, very young, and is going through a stressful period in his life at the moment, with the transition to full-time school, and that the child is being neglected, emotionally, by his parents, the suggested intervention is that the family attempt to sit down together at all mealtimes. This would give the family an opportunity to be together and would allow the child time to settle down with his parents and to feel comfortable enough to be able to tell them about his worries and his concerns. As shown by Arnold (1990), it is often enough for a child to be given the space to talk for the child to feel less stressed, and to recover from the symptoms of stress they were suffering. This intervention is expected to be effective in that it would allow connections to be made again between the child and his parents, and his brother, allowing some repair of the disrupted parent-child relationship (Finlay et al., 2005; p. 64). The need for families to have a space (both physical and temporal) where they can be together is paramount, in terms of allowing each family member to interact with each other, allowing them to discuss their worries and concerns and allowing, to some extent, the stressors to be relaxed. This is especially important for a young child who needs to feel protected. Without the protection of their families, their parents, young children can begin to feel vulnerable, with this vulnerability allowing for stressful events to have a far greater negative effect than usual on their responses to stress (Arnold, 1990). By sitting down together as a family, by talking and being listened to, the child can externalize his worries and, once shared, these worrie s can be dealt with in the most appropriate ways. Indeed, recent studies have shown that families who eat meals together have children who are more emotionally healthy than those families who do not eat together (Fivush and Duke, 2005; Duke et al., 2004). In summary, the suggested intervention in this case is to sit down together, as a family, to eat together. It is important to realize that such an intervention can have major effects on the sense of belonging a child has, which, in turn, can reduce their sense of vulnerability and can increase their ability to deal with stressful situations, and to avoid suffering from stress. This type of interaction can also lead to greater levels of family cohesiveness and resilience, having the beneficial side effect of contributing to a general reduction in family-level stressors. References Alfven, G. et al. (2008). Stressor, perceived stress and recurrent pain in Swedish schoolchildren. Journal of Psychosomatic Research 65(4), pp. 381-387. Arnold, E.L. (1990). Childhood Stress. John Wiley Sons. Bauer, A.W. and Boyce, T. (2004) Prophecies of childhood: how childrens social environments and biological propensities affect the health of populations. International Journal of Behavioral Medicine 11(3), pp. 164-175. Duke, M.P. et al. (2004). Of ketchup and kin: dinnertime conversations as a major source of family knowledge, family adjustment and family resilience. The Emory Centre for Myth and Ritual in American Life, Working Paper 26, available from http://www.marial.emory.edu/pdfs/Duke_Fivush027-03.pdf [Accessed on 3rd October 2008]. Finlay, L. et al. (2005). Understanding Health. The Open University. Fivush, R. et al. (2004). Family narratives and the development of childrenââ¬â¢s emotional well-being. In Family stories and life course, Pratt, M.W. and Fiese, B.H. (eds.), Lawrence Erlbaum Associates. Flinn, M.V. (1995). Childhood stress and family environment. Current Anthropology 36(5), pp. 181-187. Flinn, M.V. and England, B. G. (1997). Social economics of childhood glucocorticoid stress response and health. American Journal of Physical Anthropology 102(1), pp. 33-53. Flinn, M.V. (1999). Family environment, stress and health during childhood. In Hormones, Health and Behaviour, Panter-Brick, C. and Worthman, C.M. (eds.), Cambridge University Press. McEwen, B.S. (2003). Early life influences on life-long patterns of behaviour and health. Mental Retardation and Developmental Disability Research Review 9(3), pp.149-154. McEwen, B.S. (2008). Understanding the potency of stressful early life experiences on brain and body function. Metabolism 57(2), pp. 11-15. Primary Report (2007). Community Soundings: The Primary Review regional witness sessions. Available from http://news.bbc.co.uk/2/shared/bsp/hi/pdfs/12_10_2007primary.pdf [Accessed on 3rd October 2008]. Turner-Cobb, J. (2008). Childrenââ¬â¢s transition to school. Preliminary results available from http://www.bath.ac.uk/schooltransition/home#results [Accessed 3rd October 2008].
Friday, October 25, 2019
American Technological Advancements and the Cold War Essay -- Military
American Technological Advancements and the Cold War Many of the military technological advancements that have been made in the last 60 years can be attributed to the Cold War. Much of the technology developed during the period of the Cold War is still in use today by the military and government. Advancements in offensive technology are well known to just about everyone in the way of nuclear energy harnessed in the form of the nuclear bomb, but little is known about the battle for information during the Cold War. The Cold War produced some of the most advanced technology used in the fields of detection and reconnaissance in history. The United Statesââ¬â¢ detection and reconnaissance technology played a major role against communism during the Cold War, and these types of technology still play roles today. à à à à à A cold war is an ideological conflict with military standoffs while keeping diplomatic relations open. The Cold War consisted of two sides (or Superpowers); the first was the United States, who believed in and practiced capitalism, the opposing side was the Soviet Union, who believed in and practiced the idea of communism. Many historians dispute the start time of the conflict; however, it began some time after World War II and dragged on until the collapse of the Soviet Union in 1989. The Cold War Project Group Online claims ââ¬Å"the advancement of technology during the Cold War was greater than that of any one time periodâ⬠(ââ¬Å"The Arms Raceâ⬠). The war developed nuclear missiles and many other technological advancements taking the world into a new era, the Nuclear Era. It was estimated at one time the United States and the Soviet Union could nuke the world seven times over; the governments realized the pointlessness of so many nuclear missiles a nd turned their attention toward other ways to get an upper hand in the conflict. Tensions ran high during this time; without military confrontation, research and resources were redirected towards other fields of technology such as detection systems, surveillance equipment, and underwater technologies. à à à à à The North American Aerospace Defense Command, other wise known as NORAD, is a series of radar stations in North America that were built in 1950s. NORAD is a joint United States and Canadian organization that provides warnings and aerospace control for North America. The North American Aerospace Defense Comm... ...ent, they have found usefulness in todayââ¬â¢s world through reassessing their mission or in scientific research. The art of reconnaissance changed during the Cold War with the invention of the spy satellite, the U2 Spy Plane, and the nuclear powered submarines. Today much of the photo taken by the United States spy satellites and U2 Spy Planes are classified but they are still used today as a part of the military and the Center Intelligent Agency to identify threats just as they did during the Cold War; submarines The tracking down and monitoring Soviet submarines movements during the Cold War was one of the major missions of the nuclear submarines, unfortunately today the submarine force of the United States is slowly shrinking do to budget cut with in the military. Fear and uncertainty surrounded the Cold War, however thanks to these technological advancements during the Cold War it helped to keep offensive weapons form being fired and destroying the world. Unfortunately on ly a few of these technologies have found there way into the world today. The Cold War was a conflict that brought fear to Americans but also brought the United States new technology that is still around today.
Thursday, October 24, 2019
The Influence of Temperature in the Forward Osmosis Process
Chapter FourMathematical Model Chapter Four THEORETICAL ANALYSISMA andMathematical Modeling Purpose of the survey is to probe of temperature as a factor that influences the conveyance of H2O across the membrane in FO procedure. The steady-state theoretical accounts have been developed to foretell H2O ià ¬Ã¢â¬Å¡ux (JouleTungsten) as map of temperature (Thymine) and bulk concentration (C) ( i.e. Draw and Feed concentration ) . It was besides study the consequence of temperature on some belongingss, such as Solute diffusion coefficient (CalciferolSecond) , Mass transportation coefficient (K) , Permeability coefficient (A) and Solute electric resistance (Km) . 4.1 Osmotic Pressure The osmotic force per unit area (?) of a solution depends on the concentration of dissolved ions in solution and the temperature of solution, and can be computed by utilizing Va n't Hoff equation: WhereNis the vanââ¬â¢t Hoff factor ( histories for the figure of single atoms of a compound dissolved in the solution ) ,?is the osmotic coefficient,Cis the molar concentration ( molar concentration ) of the solution,Roentgenis the gas invariable andThymineis the absolute temperature of the solution. The vanââ¬â¢t Hoff factor is introduced to cover divergences from ideal solution behaviour that include finite volume occupied by solute molecules and their common attractive force as in new wave derWaals attractive force ( Howard, 2003 ) . Table 4.1 show osmotic coefficients (?) for a figure of solutes of physiological importance ( Khudair, 2011 ) . For all solutes?depends on the substance and on its concentration. As the concentration of any solute attacks zero its value of?attacks 1. In ideal solution,?= 1 ( Glass tone, 1974 ) . Table 4.1 Osmotic Coefficients (?) and Vanââ¬â¢t Hoff Factor ( N ) for a Number of SolutesSubstanceVanââ¬â¢t Hoff Factor (N)Osmotic Coefficients ( ? )NaCl20.93KCl20.92HCl20.95New hampshire4Chlorine220.92NaHCO320.96CaCl230.86MgCl230.89Sodium2So430.74MgSO420.58Glucose11.01Sucrose11.024.2 Concentration Polarization 4.2.1 External Concentration Polarization Concentration polarisation ( CP ) is the accretion of solutes near the membrane surface and has inauspicious effects on membrane public presentation. The ià ¬Ã¢â¬Å¡ux of H2O through the membrane brings feed H2O ( incorporating H2O and solute ) to the membrane surface, and as clean H2O ià ¬Ã¢â¬Å¡ows through the membrane, the solutes accumulate near the membrane surface. Equations for concentration polarisation can be derived from ià ¬?lm theory and mass balances. Harmonizing to ià ¬?lm theory, a boundary bed signifiers at the surface of the membrane. Water and solutes move through the boundary bed toward the membrane surface. As H2O base on ballss through the membrane, the solute concentration at the membrane surface additions. The concentration gradient in the boundary bed leads to diffusion of solutes back toward the majority provender H2O. During uninterrupted operation, a steady-state status is reached in which the solute concentration at the membrane surface is changeless w ith regard to clip because the convective ià ¬Ã¢â¬Å¡ow of solutes toward the membrane is balanced by the diffusing ià ¬Ã¢â¬Å¡ow of solutes off from the surface. A mass balance can be developed at the membrane surface as follows: Mass accretion = mass in ? mass out ( 4.2 ) With no accretion of mass at steady province, the solute ià ¬Ã¢â¬Å¡ux toward the membrane surface must be balanced by ià ¬Ã¢â¬Å¡uxes of solute ià ¬Ã¢â¬Å¡owing off from the membrane ( due to diffusion ) and through the membrane ( into the permeate ) as follows: WhereMeteris mass of solute,Jouletungstenis the experimental permeate H2O flux,Tis clip,CalciferolSecondis the diffusion coefficient of the solute,omegathe distance perpendicular to membrane surface,Cpeis the solute concentration in the permeate andEââ¬Ëis the surface country of membrane. Equation 4.3 applies non merely at the membrane surface but besides at any plane in the boundary bed because the net solute ià ¬Ã¢â¬Å¡ux must be changeless throughout the boundary bed to forestall the accretion of solute anyplace within that bed ( the last term in equation 4.3 represents the solute that must go through through the boundary bed and the membrane to stop up in the permeate ) . Rearranging and incorporating equation 4.3 across the thickness of the boundary bed with the boundary conditions C ( 0 ) = CMeterand C ( ?Bacillus) = CF, cell, where CF, cellis the concentration of provender cell solution and CMeteris the concentration at the membrane surface, are done in the undermentioned equations: Integration outputs WhereKis the mass transportation coefficient and?Bacillusthickness of the boundary bed, rearranging the equation 4.6 when utilizing the vanââ¬â¢t Hoff equation the eventually theoretical account from the concentrative external concentration polarisation at each permeate flux, could be calculated utilizing: Where?F, Bis the osmotic force per unit areas of feed solution at the majority and?F, mis the osmotic force per unit areas of the provender solution at the surface membrane. Note that the advocate is positive, he pointed out that ?F, m& A ; gt ; ?F, B. The draw solution in touch with the permeate side of membrane is the being diluted at the permeate membrane interface by the permeating H2O ( Moody and Kessler, 1976 ) . This is called diluted external CP. Both dilutive external CP phenomena cut down and concentrative the effectual osmotic driving force. A dilutive external CP modulus be identified as above, merely In the present instance, the concentration of the majority greater than concentration of the draw solution at the membrane surface ( i.e. ?D, B& A ; gt ; ?D, m) ( Cath et al. , 2006 ) : Where?D, mis the osmotic force per unit areas of the draw solution at the membrane surface and?D, Bis the osmotic force per unit areas of draw solution at the majority. The general equation depicting H2O conveyance in FO, RO, and PRO is ( Cath et al. , 2006 ) : Where,Athe H2O permeableness invariable of the membrane, ? the contemplation coefficient, and a?â⬠P is the applied force per unit area. For FO, a?â⬠P is zero ; for RO, a?â⬠P & A ; gt ; a?â⬠? ; and for PRO, a?â⬠? & A ; gt ; a?â⬠P ( see figure 4.1 ) . Figure 4.1 Direction and magnitude of H2O as a map of ?P. To pattern the flux public presentation of the forward osmosis procedure in the presence of external concentration polarisation, we start with the flux equation for forward osmosis, given as We assume that the salt does non traverse membrane, the osmotic contemplation coefficient (?) , assume equal 1. Equation 4.10 predicts Flux as maps of driving force merely in the absence dilutive external concentration polarisation or concentrative, which may to be valid merely if the permeating flux is excessively low. When higher flux rates, must be modified to include this equation both the dilutive external concentration polarisation and concentrative: Figure 4.2 ( a ) shows this phenomenon with a dense symmetric membrane ( McCutcheon and Elimelech, 2006 ) . 4.2.2 Internal Concentration Polarization If the porousness support bed of asymmetric membrane confronting feed solution, as is the instance in force per unit area retarded osmosis ( PRO ) , Polarization bed is established along interior of heavy active bed as H2O and solute propagate the porousness bed ( Figure 4.2 ( B ) ) . This is referred to as concentrative internal concentration polarisation, this phenomenon is similar to concentrative external concentration polarisation, except that it takes topographic point within the porous bed, and therefore, can non be underestimated by cross flow ( Lee et al, 1981 ) Obtained look patterning this phenomenon in force per unit area retarded osmosis ( Loeb et al. 1997 ) . This equation describes internal concentration polarisation ( ICP ) the effects and how it links to H2O flux, salt permeableness coefficient ( B ) and H2O permeableness coefficient: WhereKmis the opposition to solute diffusion within the membrane porous support bed,Kmis defined as WhereSecondthe membrane structural parametric quantity,?mis the thickness,?is the tortuousness and?is the porousness of the support bed,Kmis a step how easy it can be dissolved widespread support inside and outside Layer, and hence is a step of the strength of ICP. We maintain the usage of theKmterm due to convention established in old surveies on internal concentration polarisation. Salt permeableness coefficient ( B ) is about negligible compared with the other footings in the equation 4.12. Therefore, we ignore salt flux in the way of H2O flux and any transition of salt from the permeate ( draw solution ) side ( Gray et al. , 2006 ) . Therefore, flux can be solved for implicitly from equation 4.12: The exponential term in equation 4.14 is the rectification factor that could be considered the concentrative internal concentration polarisation modulus, defined as Where ?F, Iis the osmotic force per unit area of the feed solution on the interior of the active bed within the porous support. The positive advocate indicates that ?F, I& A ; gt ; ?F, B, or that the consequence is concentrative. Substitute Equation 4.8 into 4.14 to obtain an analytical theoretical account for the impact of internal and external concentration polarisation on H2O flux: All the footings in equation 4.16 are readily determined through computations or experiments. From equation we can cipher the flux of H2O through the membrane where feeding solution is placed against asymmetric support bed and the draw solution on the active bed. In forward osmosis applications for desalinization and H2O intervention, the active bed of the membrane faces the provender solution and the porous support bed faces the draw solution ( Kessler and Moody, 1976 ) . As H2O permeates the active bed, the draw solution within the porous infrastructure becomes diluted. This is referred to as dilutive internal concentration polarisation ( Figure 4.2 ( degree Celsius ) ) . ( Loeb et al, 1997 ) Descriptions likewise flux behaviour in the development of forward osmosis: When presuming that B = 0 ( i.e. , the salt permeableness is negligible ) and the equation 4.17 is agreement, are acquiring an inexplicit equation for the flux of H2O permeating: Here, ?D, Bis now corrected by the dilutive internal concentration polarisation modulus, given by Where ?D, Iis the concentration of the draw solution on the interior of the active bed within the porous support. The negative advocate because the H2O flux is in the way off from the membrane active bed surface, In other words, the concentration polarisation consequence in our instance is dilutive, intending that ?D, I& A ; lt ; ?D, Bby replacing equation 4.7 into 4.18, we get The footings in equation 4.20 are mensurable system conditions and membrane parametric quantities. Note that here ; dilutive internal concentration polarisation is coupled with concentrative external concentration polarisation, whereas in the equation 4.16, concentrative internal concentration polarisation was coupled with dilutive external concentration polarisation. In each of these instances, the external concentration polarisation and internal concentration polarisation moduli all contribute negatively to the overall osmotic drive force. The negative part of each addition with higher flux, which suggests a self-limiting flux behaviour, this implies that increasing osmotic drive force will supply decreasing additions in flux ( Tang et al. , 2010 ) . Figure 4.2 Illustration of osmotic driving force profiles for osmosis through several membrane types and orientations, integrating both internal and external concentration polarisation. ( a ) The profile illustrates concentrative and dilutive external CP. ( B ) PRO manner ; the profile illustrates concentrative internal CP and dilutive external CP. ( degree Celsius ) FO manner ; the profile illustrates dilutive internal CP and concentrative external CP (McCutcheon and Elimelech, 2006 ) . In this hunt if taking transmembrane temperature difference into history, the temperature being next to membrane surface will besides differ from that in bulk solution due to the happening of heat transportation. Hence, utilizing vanââ¬â¢t Hoff jurisprudence for computation of osmotic force per unit area requires the temperature points to be purely in line with the concentration points as WhereC,TDandTFis the concentration, temperature draw and temperature, with the inferiors F, cell ( feed cell solution ) and D, cell ( draw cell solution ) . The theoretical account to foretell H2O ià ¬Ã¢â¬Å¡ux can be rewritten to a modiià ¬?ed by replacing equation 4.21 and 4.22 in 4.20, we get Figure 4.3 gives the conventional illustration of the concentration and temperature proià ¬?les in FO procedure operated under active bed ââ¬â provender solution ( ALââ¬âFS ) . Figure 4.3Conventional diagram of mass and heat ià ¬Ã¢â¬Å¡ux proià ¬?les within boundary bed and membrane during FO procedure under ALââ¬âFS manner in the presence of temperature difference ( TF, cell& A ; gt ; TD, cell) . 4.3 Heat Flux Heat transportation from the solution to the membrane surface across the boundary bed in the side of the membrane faculty imposes a opposition to mass reassign The temperature at the membrane surface is lower than the corresponding value at the majority stage. This affects negatively the drive force for mass transportation. Under steady province conditions, derived from the heat balance, the heat transportation in the single compartments of system is represented by the undermentioned equation: In which Q denotes the heat flux, and the inferiors FS ââ¬â BL, m and DS ââ¬â BL represent feed solution boundary bed, membrane and draw solution boundary bed. By stipulating the equation 4.24, we obtain WhereHis the single heat transportation coefià ¬?cient,CPthe speciià ¬?c heat of H2O,?tungstenthe H2O denseness. Rearranging the equation 4.25 gives expressed looks of temperature near the membrane surfaces as ( Zhong et al. , 2012 ) It is sensible to deià ¬?ne the temperature at interface of SL and AL by averaging theThymineF, mandThymineD, m 4.4 Heat Transfer Coefficients The finding of heat transportation coefià ¬?cientHis developed on the footing of the correlativity between Nusselt, Reynolds and Prandtl figure ( Holman, 2009 ) . For the laminar flow: For the disruptive flow: WhereNu=hL/? , Pr =CPhosphorusà µ/? ,and.Nu is the Nusselt figure,Rheniumthe Reynolds figure andPraseodymiumthe Prandtl figure. TheCPhosphorusis the speciià ¬?c heat,Literlength of the channel,à µthe dynamic viscousness, and ? the thermic conduction of NaCl solution. The valueà µis obtained harmonizing toà µ = , in which?is the solution denseness, and?the kinematic viscousness. The dependance of?on temperature can be described by Where And are the thermic conduction of H2O at temperature T and 298.15 K. The heat transportation coefficientHcalculated by Where happenNufrom equation 4.29 or 4.30 The overall heat transportation coefficientHmof FO membrane embodies the thermic conduction of both liquid-phase H2O go throughing the micro pores and the solid-phase membrane 4.5 Mass Transfer Coefficient The mass transportation coefficient is a map of provender flow rate, cell geometry and solute system. Generalized correlativities of mass transportation, which have been used by several writers ( Sourirajan, 1970 ) , suggest that the Sherwood figure,Sh,is related to the Reynolds figure,Re,and Schmidt figure,Sc,as: For the laminar flow: For the disruptive flow: Whereand.Shis the Sherwood figure,Scandiumthe Schmidt figure andvitamin DHis the hydraulic diameter, the hydraulic diameter is deià ¬?ned as Where tungsten and h the channel breadth and channel tallness severally. The parametric quantities,CalciferolSecondand?rely strongly on temperature, which can be quantitatively determined by empirical equations below. For aqueous electrolyte like NaCl,CalciferolSecondvalue of the ions is presented by ( Beijing, 1988 ) Where Nà ±is the absolute valley of ions ( i.e. Nà ±=1 ) , and ?à ±is the tantamount conduction of Na+and Clââ¬âions, estimated as ( 4.40 ) In which( 5.1Ãâ"10-3m2/? for Na ions ; 7.64Ãâ"10-3m2/? for chloride ions ) is the mention tantamount conduction at 298.15 K ; temperature coefficient,,forSodium+, and,,for, severally. The empirical equations were employed to gauge kinematic viscousness of NaCl solution as Whereis the H2O viscousness at temperature T, expressed as In whichvitamin E= 0.12,degree Fahrenheit= -0.44,-Ãâ = -3.713,I=2.792 are the fitting parametric quantities,CSecondthe NaCl molar concentration, andThymineRoentgenthe normalized temperature. There is besides another manner to cipher diffusion coefficient in the liquid stage of a dilute solution can be estimated by the Stokes ââ¬â Einstein equation if the solute radius is clearly larger than the solvent radius WhereKBacillusis the Boltzmann invariable, T ( K ) is the absolute temperature, à µ is the dynamic viscousness of the liquid and ROis the radius of the solute. To cipher diffusion coefficients in aqueous solutions predict that diffusion coefficients really linearly with temperature and reciprocally with viscousness. Indeed, harmonizing to Li and Gregory, ( 1974 ) . In instance of the stokes ââ¬â Einstein relation the diffusion coefficientD ( T )at a temperatureThymineis given as Where D( TO)is the diffusion coefficient at a mention temperatureThymineOandà µ ( T )andà µ ( TO)are the dynamic viscousnesss at temperaturesThymineandThymineO, severally. Note that temperatures are given in Kelvin. Finally the mass transportation coefficient K calculated by WhereShdiscovery from equation 4.36 or 4.37 4.6 Water Permeability Coefficient The equation ciphering pure H2O permeableness coefià ¬?cient A for FO procedure is derived from the theoretical account ; thereby the H2O ià ¬Ã¢â¬Å¡ux of rearward osmosis procedure is predicted ( Baker, 2004 ) WhereCtungstenis the H2O molar concentration,Volttungstenthe molar volume of H2O,Calciferoleffthe effectual H2O molecule diffusivity within the pores of active bed of the FO membrane Wherevitamin DSecond( 4AO) andvitamin DPhosphorus( 7.2AO) are the diameter of H2O molecule and pore, and D the evident diffusivity, which is given as Along with H2O dynamic viscousness ( à µw ) predicted by There is besides another manner to cipher membrane permeableness ( A ) ià ¬Ã¢â¬Å¡at-sheet bench-scale RO trial system was used to find the H2O permeableness coefià ¬?cient ( A ) of the CTA membrane. A membrane voucher holding an effectual surface country of 64 centimeter2was the active bed of the membrane confronting the provender solution. Mesh spacers placed in the provender channel enhanced the turbulency of the ultrapure H2O provender watercourse. A hard-hitting positive supplanting pump was used to recirculate the provender solution at 12 L/h. The FO membrane H2O permeableness coefià ¬?cient ( A ) was determined utilizing ( Lee et al. , 1981 ) . Where is the osmotic force per unit area difference across the membrane and ?P is the hydraulic force per unit area difference across the membrane. Because ultrapure H2O was used as the provender solution, was zero during the experiments. Pressure was increased from 1 saloon to 2 saloon. Pressure was held changeless at each increase for continuance of 3 h. Water ià ¬Ã¢â¬Å¡ux through the membrane was calculated based on the increasing weight of the permeant H2O on an analytical balance. The temperature was held changeless at 25OC. See figure 4.4 Figure 4.4 Flux vs. force per unit area and the swill is representedH2O permeableness coefià ¬?cient ( A ) . 4.7 Recovery Percentage The recovery factor measures how much of the provender is recovered as permeate. It is reported as a per centum ( Al-Alawy, 2000 ) . The recovery of the membrane was calculated by spliting the overall of permeate rate by the provender rate solution. Recovery, or transition, is defined by: WhereVoltPhosphorusis the overall permeate volume andVoltFis the provender volume solution. Figure 4.5 the flow chart of patterning FO H2O flux at different temperature matrixes. 1
Tuesday, October 22, 2019
The Others-Movie Review
Nurul Hazwani Bt Hatta M12L THE OTHERS Movie Review The Others is one of the psychological horror movies that impress me with its good story plot and suspense elements. It was written, directed and scored by Spanish director Alejandro Amenabar, starring Nicole Kidman and Christopher Eccleston. It is inspired partly by the 1898 novella The Turn of the Screw. Grace Stewart (Nicole Kidman) is a Catholic mother who lives with her two small children in a remote country house in the British Crown Dependency of Jersey, in the immediate aftermath of World War II.The war was playing vital role in being contributing factor that cause depression in Grace. The stress is the triggering element that cause phychology disorder in her. The children, Anne and Nicholas have an uncommon disease, xeroderma pigmentosa, characterized by photosensitivity, so their lives are structured around a series of complex rules designed to protect them from inadvertent exposure to sunlight. The new arrival of three se rvants at the house ââ¬â an aging nanny and servant named Mrs.Bertha Mills ,an elderly gardener named Mr. Edmund Tuttle, and a young mute girl named Lydia ââ¬â coincides with a number of odd events, and Grace begins to fear that they are not alone. Anne draws pictures of four people: a man, a woman, a boy called Victor, and an old woman, all of whom she says she has seen in the house. A piano is heard from inside a locked room when no one is inside. Grace finds and examines a ââ¬Å"book of the dead,â⬠which shows mourning portraits taken in the 19th century of recently deceased corpses.I was so shocked when the doors which Grace believes to have been closed are found mysteriously ajar. Grace tries hunting down the ââ¬Å"intrudersâ⬠with a shotgun but cannot find them. She scolds her daughter for believing in ghosts ââ¬â until she hears them herself. Eventually, convincing herself that something unholy is in the house, she runs out in the fog to get the local priest to bless the house. Meanwhile, the servants, led by Mrs. Mills, are clearly up to something of their own. The gardener buries a headstone under autumn leaves, and Mrs.Mills listens faithfully to Anne's allegations against her mother. Outside, Grace loses herself in the heavy fog, but she miraculously discovers her husband Charles who she thought had been killed in the war, and brings him back to the house. Charles is distant during the one day he spends in the house, and Mrs. Mills is heard telling Mr. Tuttle, ââ¬Å"I do not think he knows where he is. â⬠Grace later sees an old woman dressed up like her daughter. Grace says, ââ¬Å"You are not my daughter! â⬠and attacks her.However, she finds that she has actually attacked her daughter instead. Anne refuses to be near her mother afterward, while Grace swears she saw the old woman. Mrs. Mills tells Anne that she too has seen the people, but they cannot yet tell the mother because Grace will not accept what she is not ready for. Charles is stunned when Anne tells him the things her mother did to her. He says he must leave for the front and disappears again. After Charles leaves, Anne continues to see things, including Victor's whole family and the old woman.Grace breaks down to Mrs. Mills, who claims that ââ¬Å"sometimes the world of the dead gets mixed up with the world of the living. â⬠At last, I know that actually, it is Graceââ¬â¢s family who is dead, not the intruders. The intruders are the living people who bought the house after the death of Graceââ¬â¢s family. Grace and her children cannot accept the fact that they are dead. Grace may have some mental illness when she killed her children with pillow and then kill herself with a rifle.She was suffering from stress as she was feeling isolated and lonely as her husband didnââ¬â¢t come back from war. I love the suspense element and the twisting plot story. At first, I thought that the intruders are the bad guy, but actuall y Graceââ¬â¢s family is the one that possess the house and reluctant to leave their mansion even when they are dead. From this story,I learn that it is important to control our emotion and be patient in facing any difficulties in our life to lead a healthy and happy life.
Subscribe to:
Posts (Atom)