Open Access Original Research Article

Derivation of Kinetic Parameter Dependent Model for the Quantification of the Concentration and Molar Mass of an Enzyme in Aqueous Solution: A Case Study on Aspergillus oryzea α-amylase

Ikechukwu Iloh Udema

Journal of Scientific Research and Reports, Page 1-10
DOI: 10.9734/JSRR/2016/24321

Aim: The objective of the research was to verify a simple mathematical model for the determination of mass concentration and the molar mass of an enzyme in any solution using standard solution of Aspergillus oryzea alpha amylase and the action of A. oryzea alpha amylase on heat treated soluble potato starch.

Study Design: Experimental.

Place and Duration of Study: Chemistry & Biochemistry Department, Research Division of Ude International Concepts limited (RC: 862217). The research lasted for about 4 months between May and Sep, 2015, on a non – continuous basis.

Methodology: Bernfeld method of enzyme assay was used to generate data on catalytic activity of A. oryzea alpha amylase. One stock solution of the enzyme was prepared by dissolving 0.01 g of the enzyme in 100 ml of tris – HCl buffer, at pH 5 and temperature 20°C and at pH 6.9 and temperature 37°C. In each case the stock solutions were diluted to the desired concentrations.

Results: The calculated mass concentration (Emp[E]) and the calculated molar mass (EmpMPROT) of the enzyme were 107.99±7.32 mg/l and 54.58±4.87 kDa respectively at pH, 6.9 and temperature, 37°C (all mean values were from 12 calculations); The Emp[E] and EmpMPROT values were 101.47±8.06 mg/l and 51.68±5.98 kDa respectively, at pH 5 and temperature 20°C (all mean values were from 11 calculations).

Conclusion: The model can be used to determine the mass concentration of the enzyme in its crude extract and as a corollary, its molar mass can also be determined given accurate concentration and the strict adoption of the protocol described.

Open Access Original Research Article

Corrosion Inhibition and Adsorption Properties of Prosopis juliflora Leaves Extract for the Corrosion of Mild Steel in 1M HCl Solution

Mustapha Balarabe Idris, Khalid Da’u Khalid, Naziru Alhassan Muhammad, Ahmad Bala

Journal of Scientific Research and Reports, Page 1-7
DOI: 10.9734/JSRR/2016/23101

Corrosion of materials such as mild steel causes big losses in the economy of many countries due to the huge amount of funds needed in order to minimize it. The aim of this paper is to investigate the effect of Prosopis juliflora leaves extract as an effective and eco-friendly source of corrosion inhibitor for the corrosion inhibition of mild steel in 1M HCl using weight-loss method. The inhibition efficiency in the present study increases with the increase of extract concentration, but decreased with increase in temperature. The adsorption of the Prosopis juliflora extract on mild steel in 1M HCl surface was found to obey Langmuir adsorption isotherm model with R2 values very close to unity. Negative values of free energy of adsorption and activation energy ˂80 Kj/mol implied spontaneous process with physical adsorption mechanism.

Open Access Original Research Article

Statistical Analysis of Hourly Solar Radiation in Kumasi –Ghana: Bayesian Approach

Yarhands Dissou Arthur, Francis Tabi Oduro, William Obeng-Denteh

Journal of Scientific Research and Reports, Page 1-23
DOI: 10.9734/JSRR/2016/12030

The solar radiation has been known to have skewed distribution rather than normally distributed irrespective of how large the sample size. The Bayesian statistical analysis of the solar radiation sort to find out from the Bayesian perspective how solar radiation is distributed in Ghana. The paper assumed a beta distribution as the conjugate prior for the solar radiation. The posterior distribution for p where p is the probability of sunshine was determined using the Bernoulli probability distribution. In this paper the random variable X represents the event of having a high or low sunshine base on the threshold of 120kWhm-2 . A randomly selected sample of size of 1500 from each month of the year was used in the analysis. Based on the threshold value the total number of sunshine hours was calculated to help in the computation of posterior beta distribution parameters. The Bayesian analysis from the month of January through December were found to converge both for the prior and posterior mean and variances at a tolerance level of 0.0001 and 0.00001 respectively after twenty iterations. The paper confirms that there are two clusters of which the solar radiation can be placed and that these cluster all converges after twenty iteration. The prior means and posterior mean converges to 0.86000 and .76000 at the tolerance level of 0.0001 respectively while the prior and posterior variances for cluster one and two converged to 6.0E-06 and 4.0E-06 respectively at 0.000001 tolerance level. The papers finally conclude that the clusters have a greater possibility (.86000 and 0.76000) of sunshine. This is also an indication that Kumasi has higher possibility of sunshine.

Open Access Original Research Article

Necessary and Sufficient Conditions for Controllability of Double-delay Autonomous Linear Control Systems

Ukwu Chukwunenye

Journal of Scientific Research and Reports, Page 1-9
DOI: 10.9734/JSRR/2016/24348

This article formulated and proved necessary and sufficient conditions for the Euclidean controllability of double-delay autonomous linear control systems, in terms of rank conditions on the controllability matrices. The proof was achieved by the exploitation of the structure of the determining matrices, the relationship among the determining matrices, the indices of control systems and system’s coefficients of the relevant system and an appeal to Taylor’s theorem as applied to vector functions.

Open Access Original Research Article

Other Demostrative Perspective of How to See Dirichlet’s Theorem

José William Porras Ferreira, Willian de Jesus Caballero Guardo

Journal of Scientific Research and Reports, Page 1-7
DOI: 10.9734/JSRR/2016/24470

The Dirichlet’s theorem (1837), initially guessed by Gauss, is a result of analytic number theory. Dirichlet, demonstrated that:
For any two positive coprime integers and , there are infinite primes of the form a+bn, where n is a non-negative integer ( n = 1, 2,… ). In other words, there are infinite primes which are congruent to mod b. The numbers of the form a+bn is an arithmetic progression.
Actually, Dirichlet checks a result somewhat more interesting than the previous claim, since he demonstrated that:


Which implies that there are infinite primes, Untitled.png a mod b.
The proof of the theorem uses the properties of certain Dirichlet L-functions and some results on arithmetic of complex numbers, and it is sufficiently complex that some texts about numbers theory excluded it. Here is a simple proof by reductio ad absurdum which does not require extensive mathematical knowledge.

Open Access Original Research Article

Variations in Phenology and Morphology of Uapaca kirkiana Müll. Arg. Provenances at Nauko in Liwonde Forest Reserve, Malawi

Hebert Jenya, Chimuleke R. Y. Munthali, Edward Missanjo, Mike F. Chirwa, Willie Sagona

Journal of Scientific Research and Reports, Page 1-13
DOI: 10.9734/JSRR/2016/24030

Aim: To assess phenological and morphological parameters of Uapaca kirkiana Müll. Arg. provenances at sixteen years of age.

Place and Duration of the Study: The trial was established in 1997 at Nauko in Liwonde Forest Reserve, Malawi.

Methodology: Data collection on phenology and morphology (flowering, fruit production, diameter at breast height (dbh), height, and crown width) of Uapaca kirkiana provenances and families was carried out every month from flowering period up to fruiting period (January to May 2014) at sixteen years of age after out planting.

Results: The results show that there were significant (P<0.001) variations in flowering sex ratio among the provenances. Phalombe provenance did not deviate significantly from sex ratio equality. The other provenances showed significant male biased sex ratios. There were no significant (P>0.05) differences in number of fruits per tree, dbh, height and crown width among the provenances. However, Phalombe had the highest mean number of fruits per tree (365±158). The mean dbh, height and crown width were: 10.1±0.1 cm, 7.7±0.06 m, and 3.0±0.05 m, respectively. There were no significant correlation between number of fruits and dbh (r=0.326; P=0.091) and the height (r=0.119; P=0.547). However, there was significant modest correlation between number of fruits and crown width (r=0.454; P<0.05). Number of fruits had high heritability value (0.72) followed by height (0.59) and dbh (0.53), while crown width did not appear to be under high genetic control with low heritability value of 0.13.

Conclusion: The higher estimated heritability value for number of fruits per tree indicates that phenotypic selection for this trait could be highly efficient. Further studies should investigate heritability and genetic correlation between growth and desirable fruits traits (fruit size, sweetness, pulp ratio, etc) for efficient tree domestication and improvement strategy.

Open Access Original Research Article

Phytochemical Characterization and Cytotoxicity of Carissa edulis, Azadirachta indica, Cassia siamea and Harrisonia abyssinica from Masumbi Village, Siaya County-Kenya

Oduor P. Leonard, Shivairo S. Robert, Akala M. Hoseah, Muleke Charles, Regina Chepkorir, Njeru S. Ngoci

Journal of Scientific Research and Reports, Page 1-10
DOI: 10.9734/JSRR/2016/23819

Aims: To determine the phytochemicals and cytotoxicity of methanolic crude extracts of Carissa edulis, Azadirachta indica, Cassia siamea and Harrisonia abyssinica, from Masumbi village, Siaya county-Kenya.

Study Design: Qualitative analysis of the phytochemicals and brine shrimp cytotoxicity assay were done using standard procedures.

Place and Duration of Study: Plant samples were collected from Masumbi village, Siaya county-Kenya. Botanical identification of the plants’ samples was done in the Department of Biological Sciences, Egerton University and their voucher samples deposited in the departmental herbarium. Extraction, concentration, spotting and phytochemical analysis were carried out at the Department of Chemistry, Egerton University-Kenya.

Methodology: Chemical tests were done to determine the class of phytochemicals present in the methanolic crude extracts while brine shrimp cytotoxicity assay was carried out to predict the potential toxicity of the methanolic plant extracts.

Results: Extracts of four different species of plants were analyzed for their phytochemical composition. Alkaloids, flavonoids, glycosides, saponins, steroids, tannins and terpenoids were detected in the extracts. The methanolic crude extracts had LC5O values between 198.498 and 450.022  µg/ml, and were categorized as being cytotoxic.

Conclusion: In the current study the methanolic crude extracts demonstrated LC50 values less than 1000 µg/ml indicating that these plants extracts were cytotoxic.

Open Access Original Research Article

Unsteady MHD Flow in a Rotating Parallel Plate Channel under the Influence of Pressure Gradient with Hall Current Effects

M. Veera Krishna

Journal of Scientific Research and Reports, Page 1-21
DOI: 10.9734/JSRR/2016/24123

In this paper we discussed the unsteady flow of an incompressible electrically conducting viscous fluid in a rotating porous media, with a variable pressure gradient and in the presence of hall current. We have considered three different cases, like impulsive change, cosine and sine oscillations of pressure gradient. It is found that, the rotational and Lorentz forces are having significant effect on velocity profile in the presence of pressure gradient and hall current. The physical significance of various dimensionless parameter’s are discussed analytically and numerically on velocity distribution and frictional force.