Inleiding :: German Essays

Inleiding Door de druk van de publieke opinie gaan bedrijven steeds vaker rekening houden met hun omgeving. Onder deze omgeving verstaan wij niet alleen mensen die in de nabijheid van deze bedrijven wonen, maar ook het personeel en het milieu. De samenleving eist van bedrijven dat ze minder vervuilend worden en vooral ook ‘veiliger’. De overheid vertaalt deze eisen in een kader wetgeving die aangeeft aan welke eisen bedrijven moeten voldoen. De bedrijven die op het moment van het ontstaan van kaderwetgeving nog geen maatregelingen hebben getroffen om te voldoen aan de eisen worden vaak opgezadeld met hoge kosten die doorberekend worden in het product. Vervolgens blijkt echter dat de consument niet bereid is om meer te betalen voor een product. De gevolgen van deze neerwaartse spiraal laten zich raden en hebben ervoor gezorgd dat vooraanstaande strategen zich gebogen hebben over dit probleem. Zij komen over het algemeen tot de conclusie dat bedrijven door een innovatief (milie u) beleid te voeren voordelen kunnen behalen ten op zichtte van de concurrentie. Dit beleid moet een vooruitziende blik hebben in de richting van toekomstige eisen zodat op een vroeg moment maatregelen kunnen worden getroffen. Vaak blijken bedrijven hierdoor effectiever en efficià «nter te gaan werken waardoor de productiekosten vaak zelfs gaan dalen in plaats van stijgen. In jaar drie van de studie bedrijfskunde gaan wij voor het vak operationeel beheer een onderzoek uitvoeren binnen het kader van drie zorgsystemen. Deze zorgsystemen zijn veiligheids-, milieu- en kwaliteitssystemen. Het bewustzijn dat kwaliteitssystemen grote voordelen met zich meebrengen is rond 1980 ontstaan1. Dit bewustzijn heeft zich ontwikkeld tot de huidige vorm van kwaliteitsmanagement. De ervaringen die hiermee zijn opgedaan kunnen gebruikt worden om toe te passen op de milieu- en veiligheidssystemen. Wij gaan proberen deze vertaalslag te maken. Dit onderzoek zal tevens aan de praktijk getoetst worden door DSM in het onderzoek te betrekken. De theoretische leidraad in ons onderzoek komt voor het grootste gedeelte uit het verplichte studiemateriaal benodigd voor het vak operationeel beheer. De basis voor onze probleemstelling en de daaruit afgeleide vraagstelling komt uit het artikel van M.E. Porter en C. van der Linde, Green and Competitive. Hierin wordt gesteld dat bedr ijven die een innovatief milieu beleid hanteren productiever worden en daardoor beter kunnen concurreren. Er wordt in dit artikel gesteld dat bedrijven te weinig kijken naar de voordelen die een innovatief milieubeleid met zich mee brengt en teveel kijken naar de statische kosten.

Physics, Energy

Romar M. Cabinta EXERCISES 15 WORK, ENERGY, AND POWER A. CONCEPTUAL QUESTIONS 1. Is work done when you move a book from the top of the desk to the floor? Why? Yes. It is because the displacement of the book from the top of the desk to the floor and the force that is applied to the book is parallel with one another. 2. State the law of Conservation of Mechanical Energy in two ways? The law of conservation of energy states that energy may neither be created nor destroyed. Therefore the sum of all the energies in the system is a constant. TMEinitial=TMEfinal 3. Explain the basic ideas that govern the design and operation of a roller coaster.A roller coaster is operated and designed through the application of Physics. The law of Conservation of Energy governs the changes in a coaster's speed and height. Simply put, the higher an object is off the ground, the more potential energy it has – that is, potential to gain speed as it falls. As it falls toward the ground, that potential e nergy changes to kinetic energy, or energy of motion. The sum of the two types of energy is constant, but a roller coaster must maintain an adequate balance of potential and kinetic energies to deliver a thrilling ride. . An inefficient machine is said to â€Å"waste energy†. Does this mean that energy is actually lost? Explain. Energy is never lost. An inefficient machine wastes energy by converting it to an unproductive state. A machine, such as a motor car engine has the primary task of converting the energy in the fuel to motion of the car. It is unproductive because a large proportion of the fuel's chemical energy is dissipated in the form of noise, heat, vibration etc. so that only a small proportion is actually used for its prime purpose. 5.Is it possible for a simple machine to multiply both force and speed at the same time? Why? It is impossible for a simple machine to multiply both force and gain speed at the same time. It is because the gain in speed of a machine i s the result of an exertion of a lot more force and therefore do not take place at the same time. One best example is a bicycle crossing a steep hill requires a greater force to be exerted to be able to gain speed. B. PROBLEMS 1. Starting from rest, 5-kg slides 2. 5 m down a rough 30 ° incline. The coefficient of kinetic friction between the block and the incline is 0. . Determine the work done by (a) the force of gravity; (b) the friction between the block and incline; (c) the normal force; and (d) the net force on the block. W=5kg9. 8kgs2 W=49 N a. ) W=Fd W=Wsin30 °(2. 5m) W=49sin30 °(2. 5m) W=61. 25 J b. ) W=-Fd W=-? kNd W=-(0. 4)(42. 44N)(2. 5m) W=-42,44 J c. ) W=0 Normal force does not exert work because it is perpendiuclar with the displacement. d. ) WT=49Nsin30 °2. 5m-0. 442. 44N2. 5m+0 WT=18. 81 J 2. Car A has twice the mass of car B, but only half as much kinetic energy.When both cars increase their speed by 5m/s, then they have the same kinetic energy. What were t he original speeds of the two cars? CAR A CAR B mass=2mB mass=mB KEA=12KEB KEB =KEB VA=5ms VB =5ms VA=2KEAmA KEA=KEB VA=2(12KEB)2mB 12mAv=12mBv 2122mB5=12mB5 VA=KEB2mB 10mB4=5mB2 VB=KEBmB 5mB2=5mB2 3. A 400-g bead slides on a curved frictionless wire, starting from rest at point A. Find the speed of the bead at point B and point C. 400g? 1kg1000g=0. 4 kg PEA=mgh PEA=(0. 4 kg)(9. 8)(5m) PEA=19. 6 J PEB=(0. 4)(9. 8)(0) PEB=0 J KEA=12mv2=120. 4kg02=0 J TME=PEA+KEA=19. 6 J+0 J=19. 6 J KEB=TME-PEB=19. 6-0=19. 6 J KEB=12mvB2 19. 6 J=120. 4 kgVB2 VB=39. 2 J0. 4 lg=9. 90 m/s PEC=mgh=(0. 4)(9. 8ms22m=7. 84 J KEC=TME-PEC=19. 6 J-7. 84 J=11. 76 J KEC=12mv2C 11. 76=120. 4kg) (v2C Vc=23. 2 J0. 4 kg=76. 67 m/s 4. A tandem (two-person) bicycle team must overcome a force of 34 lbs. to maintain a speed of 30 ft. /s. Find the power required per rider, assuming they contribute equally. Express your answer in horsepower. F=34 lb F1=17 lb=F2 P1=F1v=17 lb30fts=510 ftlbs? 1hp550 ftlbs=0. 93 hp P2=F1v=17 lb30fts=510 ftlbs? 1hp550 ftlbs=0. 93 hp 5. A pump is required to lift 200 L of water per minute from a well 10 m deep and eject it with a speed of 20m/s. (a) How much work is done per minute in lifting the water? (b) How much in giving its kinetic energy? What horsepower engine is needed if it is 80% efficient? a. ) W=mgh+12mv2=200kg? 0m? 9. 81kgm2+12? 200kg? 20ms2=59620Js=993. 67J/min b. ) W=12mv2=12200kg20ms2=40000 J c. ) HP=59620js? 0. 8? 746js=99. 899 hp EXERCISES 16 LINEAR MOMENTUM A. CONCEPTUAL QUESTIONS 1. Which has greater momentum, a ten wheeler truck at rest or a moving motorcycle? Why? A moving motorcycle has a greater momentum than the truck. A truck at rest has zero momentum because an object has to be moving in order to have a momentum. 2. How does impulse differ from force? Impulse is the product of force and the time interval of the application of force; while force is just a factor that affects an object’s impulse when it is at motion. 3.Why is it incorrect to say that impulse equals momentum? It is not right to say that impulse is equal to momentum because impulse is the measure of the change in momentum and therefore an object with constant and non-changing momentum has zero impulse. 4. What is the function of seatbelts and airbags in automobile? The function of seatbelts and airbags in an automobile is to increase the time of a force to reach its destination, which results to a lesser impact of objects that can collide to a passenger and therefore will have a higher chance for his/her life to be saved. 5. Distinguish between an elastic collision and inelastic collision.In elastic collision, the momentum and the kinetic energy are conserved; and its coefficient of restitution is equal to one. However in inelastic collision, the kinetic energy is not conserved and the coefficient of restitution is zero. B. PROBLEMS 1. A 10,000-kg truck has a speed of 100 km/h? (a) what is its momentum? What speed must a 5,000-kg truck attain in order to have (b) the same momentum? (c) the same kinetic energy? a. ) P=mv=10000 kg27. 78ms=2. 78? 105kg? m/s b. ) P=mv 2. 78? 105kg? ms5000kg=5000 kgv5000 kg v=55. 6 m/s c. ) KE=12mv2 KE=121000027. 782 KE=3. 86? 106J KE=12mv2 3. 86? 106J=125000kgv2 v=7. 72? 106J500kg v=39. 29 m/s . A car is stopped for a traffic signal. When the light turns green, the car accelerates, increasing its speed from 0 to 60 km/h in 0. 8 s. What are the magnitudes of the linear impulse and the average total force experienced by a 70-kg passenger in the car during the time the car accelerates? J=m? v J=(70 kg)(16. 67ms) J=1166. 9 kg? m/s J=Ft=Jt F=1166. 9 kg? ms0. 8s=1458. 63 N 3. A 5-g object moving to the right at 20cm/s makes elastic head on collision with a 10-g object that is initially at rest. Find (a) the velocity of each object after the collision and (b) the fraction of the initial kinetic energy transferred to the 10-g object.PT=PT' mAvA+mBvB=mAvA'+mBvB' 5g20cms+10g0=5g-vA'+(10g)(vB') 100=-5vA+10vB' 20=-vA+2vB' 20=-vB+20 +2vB' vB'=0 cm/s e=(vB'-vA')/(vA-vB) 1=(vB'-vA')/(20 cm/s-0cm/s) 20=vB'-vA' vA'=vB'-20 vA'=0-20 vA'=-20 cm/s 4. After a completely inelastic collision between two objects of equal mass m, each having initial speed v, the two move off together with speed v/3. What was the angle between their initial directions? P1x + P2x = Pfx = Pf,  P1y+P2x = 0. 2mv cos? = 2mv/3, cos? = 1/3, ? = 70. 5o. The angle between their initial directions is 2? =141  ° 5. A stone whose mass is 100 g rest on a frictionless horizontal surface.A bullet of mass 2. 5 g, travelling horizontally at 400 m/s, strikes the stone and rebounds horizontally at night angles to its original direction with a speed of 300 m/s. (a) Compute the magnitude and direction of the velocity of the stone after it is struck. (b) Is the collision perfectly elastic? a. ) Assume that the bullet is traveling in the positive x-direction and that the stone has components of  velocity  vx and vy after the collision . Equating momentum before and after in these directions. 0. 0025 kg x 400ms=0. 1 kg vx vx = 10 m/s 0. 1 vy= 0. 0025 x 300 vy = 7. 5 m/s Magnitude of velocity = v(102+7. ) = 10. 37 m/s Angle =tan-1(vy/vx) = 36. 87 deg to the x-axis b. ) No. EXERCISES 16 LINEAR MOMENTUM A. CONCEPTUAL QUESTIONS 1. What is Hooke’s Law? Hooke's law  of  elasticity  is an approximation that states that the extension of a spring is in direct proportion with the  load  applied to it. Many materials obey this law as long as the load does not exceed the material's  elastic limit. Materials for which Hooke's law is a useful approximation are known as  linear-elastic  or â€Å"Hookean† materials. Hookean materials are a necessarily broad term that may include the work of muscular layers of the heart.Hooke's law in simple terms says that  stress  is  directly proportional  to  strain. Mathematically, Hooke's law states that 2. When is a material said to be elastic? A mate rial is called elastic if the deformation produced in the body is completely recovered after the removal the load. For ideally elastic materials, a single valued (linear) and time independent relation exists between the forces and the deformations. Although it is hard to find an ideally elastic material, i. e. , A Hookean solid, most of the materials can be considered elastic at least for a specific range. 3.Which is more elastic, a rubber band or spiral steel spring? Why? Spiral steel spring is more elastic than rubber band because it has greater elastic limit and ultimate strength than a rubber band because it has greater elastic limit and ultimate strength than a rubber. 4. What is the difference between the elastic limit of a material and its ultimate strength? Why are these concepts of special importance to construction engineers? Elastic limit is the maximum stress that can be applied to a material without being permanently deformed while ultimate strength is the stress requir ed to cause actual fracture to a material.These concepts are important to construction engineers because it gives them the idea of what materials are perfect for the construction and those that are fragile. 5. Which is more compressible, alcohol or water? Why? Alcohol. It is because alcohol has higher compressibility and accepts a greater pressure than on water. B. PROBLEMS 1. A nylon rope used by mountaineers elongates . 5 m under the weight of an 80-kg climber. (a) If the rope is 50 m in length and 9 mm in diameter, what is the Young’s Modulus for this material? (b) If Polson’s ratio for nylon is 0. , find the change in diameter under this stress. a) y=F? LoA? L y=(784N)(50m)Pi4. 5Ãâ€"10-32(1. 5 m) y=4. 11Ãâ€"108 Pa b) ? tto=- LL0 ?t=- LtoLo=-0. 21. 59Ãâ€"10-3m50m=-5. 4? 10^-5 2. The elastic limit of steel elevator cable is 2. 75Ãâ€"108 N/m2 Find the maximum upward acceleration that can be given a 900-kg elevator when supported by a cable whose cross-section is 3 cm2, if the stress is not to exceed ? of the elastic limit. Maximum stress allowed:14(2. 75? 108=6. 875? 104 Pa Force force this stress=stress ? area=6. 875? 104 x0. 0003=20. 625 N=Fup Fup=mg+ma 20. 625=900(9. 81)+900(a) a=13. 11 m s-2 . The deepest pint in the ocean is the Mariana trench, about11 km deep. The pressure at this depth is huge, about 1. 13? 108 Pa. (a) Calculate the change in volume of 1000 L of seawater carried from the surface to this deepest point in the Pacific Ocean. (b) The density of seawater at the surface is 1. 025g/cm3. Find its density at the bottom. 4. If the shear stress in steel exceeds 4Ãâ€"108 N/m2, the steel ruptures. Determine the shearing force necessary to (a) shear a steal bolt 1. 0 cm in diameter and (b) punch a 1. 0-cm diameter hole in steel plate 5mm thick. a. ) FA= 4x108Nm2= F/R2 = F/*0. 1m2 F = 125663. 706143592N b. ) FA= 4x108Nm2= F/2RT= F/2*0. 005 m*0. 005m F = 63,000 N 5. In the figure below, 103 kg uniform log hangs by two steel wires, A and B, both of diameters 2. 4 mm. initially, wire A was 2. 5 m long and 2. 0 mm shorter than wire B. The log is now horizontal. a) What are the tensions in wires A and b? Since the log is not moving: FA + FB –mg = 0 Since the log is horizontal: LA + DLA = LB + DLB = LA + l + DLB, DLA = DLB + l, where l = 2 mm is the original difference in lengths between A and B. Which gives: b) What is the ratio of distance a and b?

Stem Cell Research - 872 Words

Rendering itself as a basic unit of growth and development, stem cells are essential in early life. They are small, unspecialized cells capable of reproducing and differentiating into different cell types. These cells can turn into a functional cell such as a muscle cell, organ-specific cell, brain cell, or a red blood cell. Despite controversy, stem cell research has given life back to suffering individuals and brought hope to the medical field. Along side many other major advancements of biology in the last century, stem cell research has taken off and found tremendous success just in the last fifteen years. In 1981 embryonic stem cells were first isolated from early mice embryos by American Biologists. By1986, scientist became familiar with mice stem cells and soon reports arose of successful attempts of converting mice fibroblasts into myoblasts by using only a single gene. Proving evidence that it is possible to convert one type of adult cell into another. Finally, by 1998, a re search team from the University of Wisconsin reported the first successful formation of human embryonic stem cells derived from early embryonic cells. This research was the first to demonstrate that it was possible for human stem cells to be manipulated and differentiated. Since the authorization in 2001 by President Bush to grant federal funding for research of stem cell lines, there has been a medical breakthrough in the use of human stem cells. Stem cells are now being examined in how theyShow MoreRelatedStem Cell Research : Stem Cells1338 Words   |  6 Pages Stem Cells Stem cells are cells that are found throughout the human body. They reproduce over a long period of time without changing. Stem cells can produce specialized cells, such as brain, muscle or lung cells. Stem cells in the last few years have recently made a big debut because medical professionals have discovered so many unique qualities to stem cells. They are on the cutting edge of medicine because of all their uses and the qualities that make them so unique from any other cell in theRead MoreStem Cell Research : Stem Cells1416 Words   |  6 PagesSTEM CELLS In this report, I mainly focused on Stem-Cells. You will read about Stem-Cells and its history from the moment this term was known. Also, you will know the Sources, properties, and the types of Stem-Cells. In addition, you will know some of the pros and cons researches about Stem-Cells. Stem-Cells are cells that have the ability to divide and multiply and renew itself. †¢ Sources of Stem-Cells: 1- The first source is Bone Marrow. 2- The second source isRead MoreStem Cell Research : Stem Cells941 Words   |  4 PagesStem cells have the extraordinary power to develop into several body cell types during early growth and development. (Stem Cell Basics). Stem cells are either embryonic: from a human fetus, or somatic: from an adult (Stem Cell Basics).These cells can be used to rebuild body tissue, treat diseases, and even cure others. They can be more effective in treatment of illness than the common treatment, such as therapy or medication. Stem cells are potentially more medically effective than traditional treatmentsRead MoreStem Cells And Stem Cell Research1310 Words   |  6 Pagesnonspecialized cells which have the potential to create other types of specific cells in order to survive? Those cells are called Stem Cells and they are very crucial to develop organisms. Stem cell research is a subject that most people in the world have a different viewpoint on. Some view the issue of stem cell research and ste m cell therapy as morally wrong and a crime against humanity, others view the study of stem cells as the next step in modern science (Reeve.) I think in some twisted way, stem cellRead MoreStem Cell Research : Stem Cells1261 Words   |  6 Pagescure diseases. Now we have stem cell therapy. Stem cells promise future cures for many currently considered to be â€Å"incurable† diseases, but with more research, we can overcome the controversy surrounding this this topic and help people live longer, improve their quality of life, and save many many lives. To understand the big hype about stem cells, one must know what a stem cell is. Stem cells have specialized functions that have the potential to become any type of cell in the body. According toRead MoreStem Cell Research : Stem Cells999 Words   |  4 PagesSTEM CELLS WORKING TO SPECIALIZE INTO CARDIAC CELLS Once the stem cells are delivered near the damaged areas of the heart, the regeneration of cardiac (heart) cells is possible. There is a lack of understanding on how or why specifically the stem cells turn into heart cells. â€Å"Recent studies indicated that the benefits associated with adult stem cell injection might come from paracrine effects, the effect of a nearby cell sending chemical and electrical signals to the stem cell, and not from myocardialRead MoreStem Cell Research : Stem Cells1416 Words   |  6 PagesDana Moua English IV 25 April 2016 Stem Cell Research What are stem cells? Stem cells are undifferentiated cells that are found in multicellular organisms. The reason for scientist’s interest in stem cells is because of the possible applications of using them. These stem cells can be used to regrow organs/tissues. By using stem cells, scientists may be able to find cures for different cancers, certain genetic diseases, and different physical trauma damages. They can be used to treat a varietyRead MoreStem Research On Stem Cell Research1747 Words   |  7 PagesEnglish 111-36 25 November 2014 Stem Cell Research Stem cell research has cultivated a new, miraculous study in the health field. The study has led to an increase in curing diseases over the past couple of decades. Before stem cell research, diseases were destroying and devastating lives continuously on end. With the use of stem cells in modern time, diseases are no longer taking control of lives. The innovation in biomedical technology, such as stem cell research, has greatly impacted the understandingRead MoreStem Cell Research : Stem Cells1999 Words   |  8 Pagesregenerative medicine, commonly known as stem cell research. Stem cells are undifferentiated cells within the body that have the capability to specialize into any tissue. They are most commonly found in cord blood, bone marrow, organ donations, placenta, and embryos . Stem cells are seen by some as a new miracle treatment, encouraging many countries to invest in their research. The transfer of information, often shared through scientific reports and research, puts this topic in a highly internationalRead MoreStem Research On Stem Cell Research1271 Words   |  6 Pages! ! ! Stem Cells Research ! ! ! ! ! ! ! Jabaree Shipp English III NCVPS Mrs.Gallos 8, December 2014 ! ! ! ! ! ! Throughout most of our lifetime on Earth many have pondered the thought of how they and the things around them have been created. They wondered what makes grass grow to what makes themselves grow mentally and physically. Through extensive research and major advancements in technology over these years, decades, and centuries we still have no answer to our own questions. But, we do however