Literature Reviews: Practice 1: Science Topics
Chong Yong Liang:
1) A Matter of Degrees: How does the tilt of Earth’s Axis affect seasons?
John P. Mills (2010) reported that the Sun will peak almost directly overhead, and generally speaking will be above the horizon (i.e. there will be daylight) during more of the day and because of this there will be more time for the sun to heat up the earth and thus making it even warmer (John P. Mills, 2010)
2) A Matter of Degrees: How does the tilt of Earth’s Axis affect seasons?
PBS learning media reported that the earths axis rests on 23.5 degree and that is what allows us to have different seasons and that if it is different than the seasons would change.
Johanna Lim Ziyun:
1) An investigation on the quality of water in Singapore
We need to ensure that the countries will have abundant and clean water. The most important basis of testing and ensuring the water not being contaminated would be with the use of the WHO Guidelines of Drinking Water Quality (Fawell & Nieuwenhuijsen, 2003).
A main concern would be the microbial growth of E. coli in the tap water. Pathogen E. coli is best known for its ability to cause intestinal diseases. Pathogenic strands of E. coli in drinking water are the most common organisms that cause highly credible gastroenteritis (Hellard et al, 2001). Organic matter in water act as a source for microbial growth, and so when water is used for public supply, disinfectants such as chlorine, hypochlorite and ozone are used to kill micro-organisms and break down organic matter (Miettinen et al, 1996).
However, a number of chemical contaminants have been identified in drinking water such as arsenic, disinfection by-products, fluoride, lead, pesticides and radon, which would lead to several associated health risks (Calderon, 2000). Hence, there has been growing interest in adverse health effects of water contaminated with inorganic metal contaminants, namely arsenic, chromium, lead, mercury and selenium. Research has also shown that in the case of waterborne arsenic, there is a consistent but small body of epidemiologic evidence of an association with one or more types of cancer (Cantor, 1997).
2) Industrail Biotechnology vs Chemical Industry
Industrial biotechnology is rapidly replacing the chemical industry via biotransformation. (Faber, 1999). It has reported various pressures (from society, business or government) for the replacement of chemical based industry by biotransformation. (Scouten, 1999) Bioprocesses face the challenge of cost (Stuart et al. 2002) because capital assets associated with the existing commercial processes are high. They have suggested biocatalysis combined with novel process engineering as improved methods for the production of valuable chemical intermediates of pharmaceutical industries. (Gjalt and Gray, 2002) They have reported more efficiency of enzymatic and biotechnological fermenation for pharmaceutical intermediates than chemical synthesis. (Breuer et al, 2004). From the studies on chiral compounds of pharmaceutical industries, Pankaj and Banerjee (2005) have highlighted the certain characteristics of phamaceutical intermediates e.g. mode of production and enantioselectivity.
Environmental pressure and a shift towards the use of agricultural-based raw materials diverged the trends towards sustainable bio-based industrial processes (Rogers et al., 2005). Allen (2006) related the emergence of modern biotechnology with the discovery of bacteria in 1675 and proteins in 1930s.
Kok Li Ying:
1) Blood pressure in childen
Blood pressure in children does vary in terms of how old. Blood pressure can be affected by activity and rest, body temperature, diet, emotional state, posture and medications. (Amy Walker, 2010)
2) Biodegradable vs Compostable
When an object is biodegradable, it means that it completely breaks down and returns to nature, decomposing into elements found in nature within a reasonably short period of time after customary disposal. Unlike biodegradable objects, compostable objects turn into humus when broken down, which provides valuable nutrients to the soil. (Annabel Griffin, 2010)
Ng Wei Jie:
1) Is using machinery really good for our health when they are used to harvest and prepare our food?
Although they are effective to harvest our crops, the machines are quite dirty, and the containers are usually never washed or replaced. (Carl Procter, 2012).
2) Is using machinery really good for our health when they are used to harvest and prepare our food?
Most foods naturally contain sufficient moisture to provide bacteria with the water they need in order to grow. Where moisture has been deliberately removed (e.g. in dehydrated foods such as milk powder, soup mixes, etc.), then bacteria will not grow whilst the food remains dry. (Sarah Wilmcow, n.d.)