Monday, 7 July 2014

Literature Review (Luke)

Question : What temperature is optimal for plants to grow ?

Thermoperiod refers to daily temperature change. Plants grow best at 10-15°F higher than the night temperature.The plant is able to photosynthesize and respire, during this temperature. This allows the plant to photosynthesize (build up) and respire (break down) during an optimum daytime temperature, and to curtail the rate of respiration during a cooler night. High temperatures cause increased respiration, sometimes above the rate of photosynthesis. This means that the products of photosynthesis are being used more rapidly than they are being produced. For growth to occur, photosynthesis must be greater than respiration. Low temperatures can result in poor growth. Photosynthesis is slowed down at low temperatures. (Erv Evans , N.D)


For most plants, warm weather is essential for seeds to germinate and sprout. Particularly in colder regions, perennial plants need the warmth of spring to break dormancy. Warm temperatures are also necessary for many plants to flower and fruit. Some plants need just a bit of warmth to grow and produce. Others that are native to tropical regions need several consecutive days of heat in the to even break ground for the season.  (ehow ,N.D)

Citations :

Evans, E. (n.d.). Temperature Effect on Plants. Temperature Effect on Plants. Retrieved July 8, 2014, from http://www.ces.ncsu.edu/depts/hort/consumer/weather/tempeffect-plants.html

What Effect Does Temperature Have on Plants?. (2008, November 5).eHow. Retrieved July 8, 2014, from http://www.ehow.com/how-does_4586563_effect-does-temperature-have-plants.html


Friday, 4 July 2014

Ideal Temperature for Bacteria to Multiply

Bacteria have varying requirements in terms of the range of temperatures in which they will grow. Those which grow at low temperatures (usually below 20°C) are calledpsychrophiles and at high temperatures (above 45°C) are thermophiles. Some spoilage bacteria fall into these categories.
Most pathogens, however, like warmth and are known as mesophiles. They will grow at temperatures between 5°C and 63°C, commonly referred to as the growth or 'dangerzoneand have an optimum temperature for growth of about 37°C. Listeria bacteria will grow very slowly below 5°C, but most pathogens become inactive (dormant) at low temperatures. They start to multiply more rapidly as the temperature rises.
At a temperature of about 37°C (human body temperature) pathogens multiply most quickly but as the temperature continues to rise, their rate slows down and they will stop growing altogether above 63°C. However, in order to destroy bacteria, temperatures must rise further. A temperature of 70°C for 2 minutes is recommended as a means of killing pathogens during the normal cooking process. (http://archive.food.gov.uk/ N.D.)

Cannibalism In Rats

Literature Review
Conklin (1997) noted that in every individual the readiness to fight is greatest in the most familiar place: in the middle of its territory. As the distance from territory increases, readiness to fight decreases proportionately as surroundings become stranger and more intimidating.There is certainly evidence that aggression has a genetic basis, at least in some animals. Some strains of rats are inherently more aggressive than others. there are also differences in circulating testosterone levels between strains of rats, the more aggressive animals having higher testosterone levels and vice-versa.

Sarah Dray (n.d) investigated the diet of wild rats. Wild rats are opportunist omnivorous eaters which eat whatever they can find. In most cases, this includes grains, fruits and vegetables, seeds and nuts and any other edibles they might find.  However, they will hunt in sometimes, catching bugs and other small animals.
CPR (n.d) stated that rats.they reach social maturity at around 5-6 months of age. At this age, male rats in particular start to behave more aggressively toward each other. They shift from harmless play fighting into more serious adult fighting. They establish their hierarchy. 

Thursday, 3 July 2014

Literature Review

Project Title: What makes ice melt the fastest?

USCB Scienceline(N.D.) states that it is possible to make ice melt faster by adding some impurities to the water. They stated that by adding impurities to the water, it lowers the melting point of the ice, causing the ice to melt faster.

Lansing State Journal(1992) states that ice melts because when the heat from the surroundings travels into the ice, the water molecules starts to move faster,similar to that of the surroundings and causing the ice to turn into water. It also states that not only salt can lower the melting point of ice, basically any substance that can be dissolved in water can have the same properties.

Table


Tuesday, 1 July 2014

What is the Scientific Method



What is Science? :
 Science is the concerted human effort to understand, or to understand better, the history of the natural world and how the natural world works, with observable physical evidence as the basis of that understanding. It is done through observation of natural phenomena, and/or through experimentation that tries to simulate natural processes under controlled conditions.


Source: http://www.gly.uga.edu/railsback/1122science2.html

The Scientific Method :
  • The scientific method is a way to ask and answer scientific questions by making observations and doing experiments.
  • The steps of the scientific method are to:
    • Ask a Question
    • Do Background Research
    • Construct a Hypothesis
    • Test Your Hypothesis by Doing an Experiment
    • Analyze Your Data and Draw a Conclusion
    • Communicate Your Results
  • It is important for your experiment to be a fair test. A "fair test" occurs when you change only one factor (variable) and keep all other conditions the same. 


Source : http://www.sciencebuddies.org/science-fair-projects/project_scientific_method.shtml 

The Engineering Method :

The engineering design process is a series of steps that engineers follow to come up with a solution to a problem. Many times the solution involves designing a product (like a machine or computer code) that meets certain criteria and/or accomplishes a certain task.


  • The steps of the engineering design process are to:
    • Define the Problem
    • Do Background Research
    • Specify Requirements
    • Brainstorm Solutions
    • Choose the Best Solution
    • Do Development Work
    • Build a Prototype
    • Test and Redesign
  • Engineers do not always follow the engineering design process steps in order, one after another. It is very common to design something, test it, find a problem, and then go back to an earlier step to make a modification or change to your design. This way of working is called iteration, and it is likely that your process will do the same! 



Source : http://www.sciencebuddies.org/engineering-design-process/engineering-design-process-steps.shtml#theengineeringdesignprocess