Refrigeration Laboratory Lab Report Example | Topics and Well Written Essays - 2000 words - 1

Refrigeration Laboratory - Lab Report Example Additionally, high water inlet temperatures substantially affect R134a temperature. Consequently, high water inlet temperatures led to rise in intermediate temperatures. In addition to that, optimal temperature is directly proportional to ambient temperature (Neese and Oravetz, 2003). This temperature in turn affects evaporation temperature of cycles that occur at low stages hence inducing the increase of optimal temperature. Result also indicated that there was a correlation between coefficient of performance, water inlet and ambient temperatures. As a result, coefficient of performance deteriorates at high water inlet temperatures and low ambient temperatures and vice versa and it is a common phenomenon in air water heat pump systems (Radermacher and Hwang, 2005). The apparatus had numerous sharp bends with narrow bores that substantially increased pressure of the refrigerant due to viscous friction. Refrigerant usually leave the evaporator chamber below ambient temperatures. This makes it gain temperature from the surrounding to increase superheat. Inadequately insulation at the suction line prevented this from happening (Venkatarathnam, 2008). The motor used to compress refrigerant, from suction pressure to discharge pressure, is not 100% efficient. This experiment opened up so many possibilities of recommendation that can be done to improve the plant and study techniques used. The entire valve at the joint should be fitted to prevent gas from escaping. The inefficient motor should also be replaced with an efficient one so as to save energy. Friction reduction measures are very important. Lubricant and oil should be smeared on the Inner lining of the walls of the suction pipes to reduce friction between the fluids and the walls. Man-made chlorine, especially Chlorofluorocarbons depletes the ozone layer making it permeable to dangerous ultra violet rays reach the earth. It was due this concern that the Montreal Protocol, an

Understanding Prejudice Essay Example for Free

Understanding Prejudice Essay What exactly is the meaning of prejudice, and what does being prejudiced mean? Prejudice is a big word with a very deep meaning. Indeed, a lot of people may not know the true sense of it and how it affects people in the society. People live in a world that is full of prejudice. It is considered as one of the negative social phenomenons and one of the main sources of problems in the world. Prejudice denotes making or predisposition to make a decision or judgment before one becomes aware of the relevant truth of a certain case or scenario. For instance, people may have heard others saying things about a certain group of individuals such as â€Å"all black people are†¦. ,† â€Å"all white people are†¦. ,† â€Å"people in third world countries are†¦,† etc. (Breen, 2006). People may think that prejudice only refers to racial prejudice that is usually directed towards people with light or dark skin. However, I have learned that prejudice has a deeper meaning than discrimination against people of a certain race or color. Rather, prejudice can also be a result of one’s gender and geographical, religious, and cultural backgrounds. Every person also has his or her own way of being prejudiced. For example, one can judge somebody by the way he or she dresses and talks or even by his or her appearance. Thus, prejudice can come from different sources such as peers, parents, school, and public organization. At the same time, it can also be directed to various types of people. There are also many different kinds of prejudice that exist in our society today. Some of them may be observed in school, at home, or even in the television. For this reason, discrimination, racism, sexism, and other forms of social problems exist in the world we live in. Hence, it is not fair and also very sad that prejudice is a widely pervasive phenomenon in the world. (Breen, 2006). It is always inevitable to become prejudiced. There are a lot of reasons why people become prejudiced. It is a fact that one can learn it from home; parents often do not recognize that they are being an example to their children. If parents are prejudiced, then it is most likely that the child will also become one because that is what he or she observes from his or her parents. Children may also become prejudiced if parents directly teach or tell the former to perceive somebody or some things in the society in a certain way. That is why at a very young age, many children start to become prejudiced already and start to judge people and things by what they believe and think of them. They also become prejudiced due to the environment that they grow up in, the school and the neighborhood that they get involved in or witnesses. The media also plays a role in influencing people to become prejudiced. The effect on prejudice of television shows and films is very substantial. There are just so many ways on how people can become prejudiced, and it is very alarming that it has become one common source of misunderstandings, fights, and disputes all over the world (Breen, 2006). It is very hard to stop prejudice; however, it can be lessened if people would try not to be judgmental on simple things that they see and observe in their environment. Proper or right education must be imposed to children especially at home and in school in order to stop prejudice and so that people will eventually look at one another without making negative judgments. On the other hand, it would be very difficult to stop this social phenomenon as prejudice has become already part of the society. In conclusion, prejudice is an attitude that is based on generalizations and stereotypes. It is very astounding how easy it is for an individual to become prejudiced on somebody or something. Nevertheless, prejudice is merely a kind of thinking or a feeling in an individual’s mind. While people will never abolish the existence of prejudice in the society, it can be lessened and prevented if everyone will just start to cooperate and make an effort in reducing it. I believe that working hand in hand toward a common objective or goal can bring different groups of people all together, regardless of their age, race and sex. Reference Breen, R. (2006). Real Life Issues: Prejudice. Great Britain: Trotman Company Limited.

Characterization of Lady Macbeth :: essays research papers

  Ã‚  Ã‚  Ã‚  Ã‚  Many have tried to define the character of Lady Macbeth, perhaps the most memorable character of Shakespeare’s legendary tale of murderous ambition, Macbeth. As the play opens and Lady Macbeth is introduced, her motives are not fully visible until her second appearance in Act II Scene 2. As her motivation is realized, it seems very detestable. As the play unfolds, it seems that Lady Macbeth is actually quite insane. In this essay I will attempt to delve into the character of Lady Macbeth and attempt to shed some light on her actions and role in Macbeth’s climax, and downfall.   Ã‚  Ã‚  Ã‚  Ã‚  When Lady Macbeth first appears in Act I Scene V, she is reading a letter sent to her by Macbeth. When Lady Macbeth learns about the witches’ prophecy, she begins doubting that Macbeth has what is necessary to take advantage of this. This is best exemplified by theses lines â€Å"What thou art promised. Yet do I fear thy nature; / It is too full o’ th’ milk of human kindness† (Pg. 318, 15-16) in this passage she is suggesting that Macbeth is full of the natural human feelings of compassion and loyalty. She then takes the responsibility of Macbeth’s prophecy coming true. She claims that she will reprimand all that impedes Macbeth from the â€Å"golden round† or the crown. In another soliloquy she claims to give up her femininity in order to be better suited for the murderous deeds ahead. So Lady Macbeth has already begun a transformation into a person who is overcome by greed and desire.   Ã‚  Ã‚  Ã‚  Ã‚  Her motivation is now clear, she desires that Macbeth become King, undoubtedly for the power, wealth, and social domination that would accompany this position. Whenever Macbeth began to falter, she began to question his manhood, in an effort to manipulate him, which caused him to put away any qualms and do the dirty deed. Towards Act III an IV Macbeth begins to take charge, but Lady Macbeth is still in the background, making sure that Macbeth’s position of King is secured.   Ã‚  Ã‚  Ã‚  Ã‚  In conclusion I feel that Lady Macbeth is by far the most compelling character in the play.

Related literature on food carts Essay

Getting a food cart franchise package: what are the advantages? Why food cart Franchise? Potential franchisees sometimes wonder if franchising is a necessary process, and may ask why they couldn’t simply start a business on their own. The findings of the government suggest that franchisees enjoy a significant competitive advantage over the stand-alone or single business operators. They showed a study that 88% of franchise companies which opened in the previous five years were still in business under the same owner and only 4% of these businesses failed. Also, a survey in that same article showed 60% percent of all new businesses that started over a 10 year period dissolved within their first six years. The percentages of success may vary with the study and that there maybe other studies out there but still reach same conclusion most suggest that a franchised business have a higher chance of success than independent, start-alone businesses. Here are some of the advantages of having a Food cart franchise: Food cart franchise are cheaper and have less lease or rent cost. Food cart franchise are transferable, since they can be moved easily or if the location is not profitable. Food cart franchise are easy to operate and manage. Food cart franchise requires one to two personnel only. Food cart franchise needs a small space/location so it is easier to find one. Food cart franchise are easy to maintain, lowering overhead costs. Food cart franchise are ideal for businesses offering limited products or services. Food cart franchise can capture a wider market because location is along the walkways of malls and commercial centers. Expansion is easy since it needs less capital. Reasons contributing to this include: A food cart franchise is a â€Å"copy† or â€Å"duplicate†, if you may, of an already successful business. The true value of a food cart franchise is the experience, know-how, and the operation procedures that comes with it. In franchising, there is the value added advantage of brand name recognition. There are also support structure from the franchise company that the franchisee can take advantage of. A franchise avoids the costly trial-and-error periods that causes so many start-up businesses to fail and close up. http://franchisebusinessphilippines.com/why-food-cart-franchise-business/ The Effect of the Marketing Practices on small shops in South African townships i.) A complete â€Å"paradigm shift† in managerial thinking, in terms of service quality deliverance through the continual education and training of staff in fields such as customer care, customer satisfaction and customer service. ii.) The product offering needs to be more consistent and reliable, ensuring that an overall perception is created within the minds of consumers. Attention needs to be given to details (such as checking expiry dates) in delivering services and products. iii.) owners/managers need to spend more time building â€Å"relationships† with their customers. This will assist in receiving regular feedback from customers in terms of customer satisfaction. It helps to develop customer loyalty as customers enjoy personalized attention. Shops in Mdantsane should, therefore, be more sensitive to the unique needs of their customers. iv.) The pricing policy of the shops in Mdantsane should also be based on accepted accounting procedures and not only on intuition. Owners/managers of shops in Mdantsane indicated low levels of adoption of the marketing strategy concept. This suggests that an opportunity exists for these owners or managers to be educated on how to adopt marketing strategies that enhance profitability. Furthermore, grocery shop owners/managers also regarded price as the most important aspect when applying the marketing strategy mix. This implies that grocery shops in Mdantsane compete primarily based on price. According to the study findings, these grocery shops also need to adopt the other 3 Ps of the marketing strategy, namely product, place and packaging in order to be more profitable. The owners/managers of grocery shops did, however, indicate that they lack the necessary funds to embark on extensive marketing practices.

Roller Coaster Physics

Individuals love to go to the amusement parks and try out the rides that are available. The most common and thrilling ride is the roller coaster. An amusement park is not an amusement park if it does not contain a roller coaster. What makes these roller coasters so fun that every amuse parks has one. A lot of people would say it is their extreme high speeds that makes it very exciting. That is a valid answer, but it is the wrong answer. The speed has nothing to do with the excitement. It is more than likely that most people travel faster on their ride along the highway on the way to the amusement park than they would in a roller coaster. Basically the thrill all comes from the acceleration and the feeling of weightlessness that they produce. Roller coasters thrill people because of their ability to accelerate them downward one moment and upwards the next; leftwards one moment and rightwards the next. How does this thrill machine work? There are two ways that this question will be answered. First, through the basic principles and then through a more advanced explanation. Roller coaster rides involve a great deal of physics. The ride often begins with a chain and motor which exerts a force on the train of cars to lift the train to the top of a tall hill. Once the cars are lifted to the top of the hill, gravity takes over and the rest of the ride works on energy transformation. There is no motor or engine that takes a train around the track. The law of physics is basically the engine of the train. At the top of the hill, the cars possess a large amount of potential energy because they are elevated very high above the ground. The potential energy depends on the mass and the height of the object. As the cars are released they lose a lot of their potential energy but they gain kinetic energy because all of the potential energy is transferred into kinetic energy. The kinetic energy depends on the mass of the object and the speed of the object. As the cars lose speed, they also lose kinetic energy, but that does not stop the whole thing, inertia is what keeps the cars moving. While the cars might slow down when they approach a new hill, it is inertia which moves it forward. Once cars go through loops, turns and smaller hills, the only forces that act upon the cars are the force of gravity, the normal force and dissipative forces such as air resistance. The force of gravity is an internal force and any work done by it does not change the total mechanical energy of the train of cars. The normal force of the track pushing up on the cars is an external force and it always times acts perpendicular to the motion of the cars and it is unable of doing any work to the train of cars. Air resistance if a force capable of doing work on the cars and taking away a bit of energy from the total mechanical energy which the cars possess. Due to the complexity of this force and the small role that it plays on the large quantity of energy possessed by the cars, it is often neglected. By neglecting air resistance, it can be said that the total mechanical energy of the train of cars is conserved during the ride. That is to say, the total amount of mechanical energy possessed by the cars is the same throughout the ride. Energy is not gained or lost, only transformed from kinetic energy to potential energy and vice versa. Now that the basics are understood, we can get into more complex things, such as the physics of making a roller coaster amusing. We have said that it is the acceleration that makes it exciting. The most exciting part of a roller coaster is when it approaches the loops, and centripetal acceleration occurs within those loops. The most common loop of a roller coaster ride is the loop that looks like a tear drop, it is not a perfect circle. These loops are called clothoid loops. A clothoid is a section of a spiral in which the radius is constantly changing, unlike a circle where the radius is constant. The radius at the bottom of a clothoid loop is much larger than the radius at the top of the clothoid loop. As a roller coaster rider travels through a clothoid loop, he/she will experiences an acceleration due to both a change in speed and a change in direction. A rightward moving rider gradually becomes an upward moving rider, then a leftward moving rider, then a downward moving rider, before finally becoming a rightward-moving rider once again. There is a continuing change in the direction of the rider as he/she will moves through the clothoid loop. A change in direction is one thing of an accelerating object. The rider also changes speed. As the rider begins to climb upward the loop, he/she begins to slow down. What we talked about suggests that an increase in height results in a decrease in kinetic energy and speed and a decrease in height results in an increase in kinetic energy and speed. So the rider experiences the greatest speeds at the bottom of the loop. The change in speed as the rider moves through the loop is the second part of acceleration which the riders experiences. A rider who moves through a circular loop with a constant speed, the acceleration is centripetal and towards the center of he circle. In this case of a rider moving through a noncircular loop at non-constant speed, the acceleration of the rider has two components. There is a component which is directed towards the center of the circle (ac) and relates itself to the direction change and the other component is directed tangent (at) to the track and relates itself to the car's change in speed. This tangential compo nent would be directed opposite the direction of the car's motion as its speed decreases and in the same direction as the car's motion as its speed. At the very top and the very bottom of the loop, the acceleration is primarily directed towards the center of the circle. At the top, this would be in the downward direction and at the bottom of the loop it would be in the upward direction. Inward acceleration of an object is caused by an inward net force. Circular motion or curved path such as a clothiod requires an inwards component of net force. If all the forces which act upon the object are added together as vectors, then the net force would be directed inwards. Neglecting friction and air resistance, a roller coaster car will experience two forces which I have mentioned earlier. The normal force is always acting in a direction perpendicular to the track and the gravitational force is always acts downwards. We will discuss the relative magnitude and direction of these two forces for the top and the bottom of the loop. At the bottom of the loop, the track pushes upwards upon the car with a normal force. However, at the top of the loop the normal force is directed downwards because the track is above the car, it pushes downwards upon the car. The magnitude of the force of gravity acting upon the passenger (or car) can easily be found using the equation Fgrav = m*g where g = acceleration of gravity (approx. 10 m/s2). The magnitude of the normal force depends on two factors which are the speed of the car, the radius of the loop and the mass of the rider. The normal force is always greater at the bottom of the loop than it is at the top. The normal force must always be of the appropriate size to combine with the force of gravity in a way to make the required inward or centripetal net force. At the bottom of the loop, the force of gravity points outwards away from the center of the loop. The normal force must be sufficiently large to overcome this force of gravity and supply some excess force to result in a net inward force. Basically the force of gravity and the force of normal are playing a tug of war and force of normal must win by an amount equal to the net force. At the top of the loop, both forces are directed inwards. The force of gravity is found in the usual way using the equation Fgrav = m*g. Once more the normal force must provide sufficient force to produce the required inward or centripetal net force.

3 Ways to Impress Everyone at Your First Job

3 Ways to Impress Everyone at Your First Job You’re fresh out of college, talented, high-achieving, and raring to prove yourself in the big bad world of work. But the classes you’ve taken and the internships you’ve had cannot quite prepare you for the ins and outs of building a career. If you’re just starting out, these three tips can be invaluable to catapulting yourself to job success.Tell them who you areYour personal story is as much a part of your career as it is your online presence. Who are you? What do you do? Where are you heading? Start defining your fantasy career arc and slowly start to make it happen. Remember no one else will tell your story for you. It’s your job to get it out there. And once you do, managers will take notice. The clearer you are, the better your chances of being considered for exciting opportunities down the line.Lead from day oneDon’t dress for the entry-level position you just landed, dress for the job you ultimately want. Show up as a leader first, an d an employee second. Don’t get too big for your britches, but make a good impression at every possible opportunity. Take care with how you dress and speak and network. Own your rung of the ladder until you outgrow it!Take charge of your careerNo one will do it for you. You’re not a victim. If you didn’t get assigned a project you wanted, or you didn’t get the big promotion, ask yourself what you could do differently next time- not why your boss was so unfair. Part of being a leader is proving you can react well to difficult situations and find a constructive way to grow. Take risks, keep learning, and keep your eye on the prize.

Rotary Rock Tumbler Instructions

Rotary Rock Tumbler Instructions The most common type of rock tumbler is a rotary drum tumbler. It polishes rocks by simulating the action of the ocean waves. Rotary tumblers polish rocks much more quickly than the ocean, but it still takes some time to go from rough rocks to polished stones! Expect the process to take at least a month from start to finish. Use these instructions as a starting point for your tumbling. Keep records of the type and quantity of rock and grit/polish, and duration of each step. Use this information to refine your technique for the best results. Rock Tumbler Materials List Rotary tumblerRocks (all the same approximate hardness in a load)Plastic PelletsSilicon Carbide Grits (You may add a 400 mesh SiC step, if desired, before polishing)Polishing Compounds (e.g. alumina, cerium oxide)Lots of Water How To Use a Rock Tumbler Fill the barrel 2/3 to 3/4 full of rocks. If you dont have enough rocks, you can add plastic pellets to make up the difference. Just make sure to use those pellets only for coarse polishing and use new pellets for the polishing stages. Keep in mind that some plastic pellets float, so make sure you add them to the proper volume before  adding water.Add water so that you can see it between the stones but do not completely cover the stones.Add grit (see chart below).Make sure your charged barrel falls within the weight allowance for the rotor to be used.Each step runs for at least a week. For the first step, remove the barrel after 12-24 hours and open it to release any gas buildup. Resume tumbling. Dont be afraid to open the barrel periodically to make sure a slurry is forming and to check the progress of the process. The tumbler should have a uniform tumbling sound, not sound like tennis shoes in a dryer. If the tumbling is not uniform, check the level of the load, formation of slur ry, or mixture of rock sizes, to make sure these things are optimal. Keep notes and have fun! Let the rough grind (60/90 mesh for hard stones, start with the 120/220 for soft stones) run until all of the sharp edges have been knocked off the stones and they are pretty smooth. You can expect to lose about 30% of each stone during the tumbling process, with almost all of the loss during this first step. If the stones are not smoothed after 10 days, you will need to repeat the step with fresh grit.After a step has been completed, rinse the stones and the barrel thoroughly to remove all traces of the grit. I use an old toothbrush to get into the hard-to-reach areas. Set aside any stones that are broken or have pits or cracks. You can add them to the first step of the next batch of stones, but they will diminish the quality of all of your stones if you leave them in for the next step.For the next step, you again want the rocks to fill the barrel 2/3 to 3/4 full. Add plastic pellets to make up the difference. Add water and grit/polish and proceed. The keys to success are making cer tain there is no contamination of steps with grit from the previous step and avoiding the temptation to move on to the next step too early. Barrel Grit Mesh 60/90 120/220 Prepolish Polish 1.5# 4 T 4 T 6 T 6 T 3# 4 T 4 T 6 T 6 T 4.5# 8 T 8 T 10 T 10 T 6# 10 T 12 T 12 T 12 T 12# 20 T 20 T 25 T 25 T Helpful Tips for Perfectly Polished Rocks Do not overload your tumbler! This is a leading cause of belt breakage and motor burn-out. When in doubt, weigh your barrel. A barrel for a 3-lb motor should not exceed a weight of 3 pounds when charged with rocks, grit, and water.Oil the tumbler bushings with a single drop of oil, but do not overdo it! You do not want oil on the belt, as this will cause it to slip and break.Resist the temptation to tumble rocks with cracks or pits. Grit will get into these pits and contaminate subsequent steps, ruining the polish of the entire load. No amount of scrubbing with a toothbrush will remove all of the grit inside a pit!Use a balanced load that includes both large and small rocks. This will improve the tumbling action.Make sure all rocks in a load are of the same approximate hardness. Otherwise, the softer stones will be worn away during the polishing process. An exception to this is when you are purposely using softer stones to fill/cushion a load.Dont wash grit down the drain! It will cr eate a clog that is impervious to drain cleaner. I rinse the grit steps outside using a garden hose. Another option is to rinse the grit into a bucket, for later disposal somewhere other than your plumbing. Dont reuse grit. Silicon carbide loses its sharp edges after about a weeks tumbling time and becomes useless for grinding.You can reuse plastic pellets, but take care to avoid contaminating the polishing stages with grit. Use separate plastic pellets for these stages!You can add baking soda, Alka-Seltzer, or a Tums to a load to prevent gas build-up.For smooth river rocks or for any softer stones (e.g. sodalite, fluorite, apatite), you may omit the first coarse grit step.For softer stones (especially obsidian or apache tears), you want to slow the tumbling action and prevent the stones from impacting each other during polishing. Some people have success adding corn syrup or sugar (twice as much as the amount of prepolish and polishing agent) to thicken the slurry. Another option is to polish the stones dry (as in no water) with cerium oxide and oatmeal. Are you interested in using a vibratory tumbler to polish rocks? Then try these instructions instead.