Decomposition Lab Report Example | Topics and Well Written Essays - 1250 words

Decomposition - Lab Report Example Nutrient is beef broth plus yeast. Beech (fagus): - belongs to the family fagaceae. Leaves are entirely or sparsely toothed, 5 - 15 cms long and 4- 10 cm broad. Rate of decomposition is faster due to low lignin content, which is a decay resistant. Decay of leaves can be estimated by the change in 1. Their mass 2. Quality (which is calculated as ratio of C: N of decayed dry material. 3. Their chemical content. 4. Changes in soil or water, which act as medium. 5. Linear wave equation Wt = Wo - Kt where Wt = mass observed after specific time period, Wo = initial weight, K = decay constant. PAGE 2PREDICTION Rate of decomposition will increase with increase in temperature and will be negligible at very high and very low temperatures. METHODAgar jelly and mini-petri dishes were used. The agar had no feed in it. It was only used as a Base to keep the leaf circles in place. The leaf circles would act as food for the microbes to Grow on. To test different temperatures 5C, 20C, 30C and 65C were used. In each dish 10 leafcircles were put . Each leaf circle had a diameter of 5mm. To make sure that thisexperiment was safe, the lid was cello taped and wasn't opened till the experiment was over .The leaf circles were then observed during a 4-week period. Any change in size of the leafMaterial could be measured.Graph paper was put behind each petri dish when measuring....an optimal temperature for microbial activity is between 35 to 45 degree C. Agar: - it is a phycocolloid extracted from red purple marine algae, which belong to class rhodophyceae. Agar is a gel at room temperature and remains firm at as high as 65 degree C. Nutrient agar will grow the largest number of different types of microbes fungi and bacteria. Nutrient is beef broth plus yeast. Beech (fagus): - belongs to the family fagaceae. Leaves are entirely or sparsely toothed, 5 - 15 cms long and 4- 10 cm broad. Rate of decomposition is faster due to low lignin content, which is a decay resistant. Based on the results above it can be said that decomposition at extreme high and extreme low temperatures is zero and the decay process increases with increase in temperature as depicted in the temperature vs. mean diameter graph. There is minimal or no microbial activity at extreme temperatures. There fore the process of decay is slow at such temperatures. Decaying process tends to be faster at warmer temperatures as it facilitates microbial growth therefore as the temperature increases the decayi9ng process also increases. 7. NUMBER OF OBSERVATIONS: Adequate numbers of observations were not made. Instead of increasing the number of dishes to 10, less number of dishes should have been used and observations made at more frequent temperatures so that optimal temperature could be calculated, 8.

Experimental Designs I Statistics Project Example | Topics and Well Written Essays - 750 words

Experimental Designs I - Statistics Project Example 4. It sets the rate of alpha error to the experiment error rate, which is usually 0.05. This is divided by comparisons in totality to type 1 error control if there is a consideration of multiple comparisons. In case, the bonferroni test is applied, there will be a print out of multiple comparison tables by SPSS providing mean differences in dependent variables among groups. The importance of these differences is also given showing 0.05 to be the differences significant level. 6. Post hoc comparisons are performed when a researcher is finding out differences, which is not limited to an individual’s theory (Gonzalez, 2008). Many tests that are carried out under post hoc apply the q statistics. If group means comparisons are chosen because of their large size, there is a variability increase expected. This must be compensated by the researcher through application of more tests, or else there will be occurrences of type 1 errors. 8. Repeated measures ANOVA is more powerful because every factor controls itself. In these designs, differences in individual subjects do not interfere with treatment group differences (Kulinskaya & Dollinger, 2007). SS stands for variation; df means the degree of freedom; MS is the variance that is arrived at by SS/df, and F is the ratio test got by dividing between MS by within MS. In the table above, the MS of within-group is less than between groups which shows that the grouping has no effect. The grouping has been done in three categories, that is, df within groups being (3-1) =2. There are 4 people in every group, therefore, df within groups is the group number multiplied by one less the number of each group: 3*2= 6. These are denominator’s and numerator’s df. From the F table with 0.0 5significance level, 5.14 is the critical value. As the F value that has been computed is less, it can be concluded that grouping variables have no effect on dependent variable. SS stands