Obesity in the US Essay Example | Topics and Well Written Essays - 2000 words

Obesity in the US - Essay Example The beginning of the 21st century is marked by obesity problems and overweight affecting American population. Statistical results and research studies suggest that obesity becomes a national problem which affected millions of adults and children around the country. Obesity is an epidemic. It tends to have more negative than positive effect on the economy and can greatly reduce ones life expectancy. The best resolution to eradicate this spreading disease is by educating people about a healthy diet and regular exercises, starting with the younger generations. Aside from surgery, a healthy lifestyle is the only option that will work (Sugarmann and Sandman 1403). This paper will discuss the background of the disease, some preventative measures that can be taken as well as a proposed solution and proposed policy. The policy that will help the nation to improve their eating habits is to educate the public on the dangers and medical quandaries that obesity causes and to help eradicate this epidemic from our nation. Obesity is defined as: "an excess of body fat, and is distinct from "overweight" (Toth and Schwartz 13) which means an excess of body weight. When contrasted with smoking and drinking, obesity at first seems like a less serious health problem. Obesity is not only more hazardous than smoking and drinking, but it also leads to a higher cost for health care and medicine. Statistics also show that obesity contributes approximately 740,000 deaths from heart diseases, 540,000 from cancer, 158,000 from stroke, and 59,000 from diabetes are mainly contributable to obesity. In many cases of Anorexia Nervosa and Bulimia Nervosa, female patients often feel pressure because they cannot accept their appearances and eventually starve themselves to stay in shape. Obesity is one of the main reasons for increases in suicides in the United States (CDC) (Pollan 2003). Pollan questions: "Since the raw materials of soda and popcorn, French fries and even hamburgers represent such a tiny fraction of their retail price (compared with labor, packaging and advertising), expanding portion size becomes a way to multiply sales without adding much to costs" (Pollan 2003'; see appendix 1). Prevalence For adults, obesity is a result of unhealthy eating behavior they follow from early childhood changing nothing during their mature years. Important detail is that people possess unhealthy eating patterns from the yearly age which lead them to overweight problem in near future. As a result, mental and physical health problems arise when two conflicting values are being absorbed by a child such as becoming more desirable if one is slim and beautiful, as opposed by a baser instinct to indulge one's gastronomical appetite (Toth and Schwartz 13) What is most commonly observed then among sufferers is their low self-esteem. They see weight reduction as the only way for them to be accepted and loved. Many of people feel that they are not good enough, they are not capable of doing anything right, and have an illusion that their appearance is always scrutinized by others, have an incorrect perspective that they would be happier and life would be better if they could just lose weight. Negative body image contrasts with media images of ideal body and the importance of physical attractiveness and supported by clothes manufacturers who "popularize" baggy life style. The problem is that many children consider that doing exercise is less delightful than other unhealthful alternatives such as watching

Investigation of Process Parameter Optimization of High Speed CNC Research Paper

Investigation of Process Parameter Optimization of High Speed CNC Milling for Composite Materials using Combined Genetic Algorit - Research Paper Example Machinability in terms of quality and productivity is of great concern in a competitive market. CNC milling performance is evaluated in terms of surface roughness, material removal rate, taper and facing. CNC machining is done initially in a number of passes an final end milling is done in a single pass. The most common machining parameters are cutting speed, feed, depth of cut. To have a balance between productivity and quality, the machining parameters need to be optimised. High speed CNC milling process needs to balance between productivity and quality of the end product. While quality is measured in terms of surface finish, the productivity is measured in terms of material removal rate. Good machinable materials acquire a smooth finish as they can be easily cut with less power. They also cause minimum damage to the tool. If the material has improved material properties then it’s machinablity becomes difficult. Hence improving machinability without sacrificing performance is a challenge. Predicting the optimal parameters for CNC milling is difficult as the milling process depends on several factors. The important factors relative to the material include the thermal conductivity, toughness, chemical properties and the microstructure of the material. The other important factors are the geometry of the cutting tool and the parameters of CNC milling process. Objectives : The aim of this research work is to †¢Find the important factors that characterise the best performance of the high speed CNC milling process. †¢Using combined Genetic Algorithm and Artificial neutral networks techniques to optimise these high speed CNC milling parameters by identifying the correlation between the factors like feed, depth of cutting and cutting speed. Based on the correlation of these parameters, the optimal set is to be determined for perfect output parameters like surface roughness and material removal rate. (4) High speed CNC Milling : CNC milling is the most fundamental operation in industrial machining. According to Mike S. Lou et al (1999 ) â€Å"The quality of the surface plays a very important role in the performance of milling as a good-quality milled surface significantly improves fatigue strength, corrosion resistance, or creep life. Surface roughness also affects several functional attributes of parts, such as contact causing surface friction, wearing, light reflection, heat transmission, ability of distributing and holding a lubricant, coating, or resisting fatigue†. Speed of the milling depends on the tool size used. If the tool size is smaller, then to avoid breakage of the tool the spindle speed required will be more. For milling with using micro tools the speed range of the spindles may be up to 60,000 rpm ( Datron white paper, 2005). Thus high speed milling involves higher RPM rates with more feed rates and small step overs. The advantage of this high speed is that there is less heating of the parts because of less time for the heat to feedback. The generated heat is 40% due to the friction and 20% due to deformation. For better quality in machining, the low milling force and cooler tools can be used so that the vibration is less. A white paper of DATRON (2005) states that â€Å"The high spindle speed reduces the chip load to less than 0.005†. Such a low chip load significantly reduces the forces between the tool and the material. High-speed/low-force machining yields less heat, reduces tool deflection, and allows machining of thinner walled work pieces. This all results in cooler machining, superior surface and edge quality, better accuracy and, as a