Archives-December  

The freeze drying behaviour of local cheese was modeled using conservation laws of mass and energy balances such as Fick’s law of mass transfer, Fourier’s law of heat conduction and the Ideal gas equation. The three models developed and simulated are the drying rate, the moisture content and the energy balance models. Three different samples of cheese labeled A, B and C obtained from Bida, Suleja and Kontagora respectively all in Niger State of Nigeria were used to investigate the drying characteristics of local cheese. The analysis of the moisture contents showed that the moisture contents decreased with drying time and that the final moisture content at any time depends on the initial moisture content. Sample A with initial moisture content of 0.0124 kg has a final moisture content of 0.00097kg after 5 hours of drying, while samples B and C with initial moisture contents of 0.009kg and 0.0104kghave their final moisture contents of 0.00001kg and 0.00010kg respectively at the end of 5 hours. When the effect of temperature on moisture loss was studied, it was observed that the moisture loss increased as the freeze drying temperature was increased from 278 to 298K. Results also revealed that moisture loss depends on the initial moisture contents of samples. For this investigation, Samples A, Band C with initial moisture contents of 0.0124kg, 0.0138kg and 0.0104kg have moisture losses of 0.00420kg, 0.00440kg and 0.00363kg respectively at the highest freeze drying temperature of 298K. When the drying rates of samples was investigated, it was found that the drying rates decreased as the moisture contents decreased and which is also a function of the initial moisture contents of samples. The validation of the model was done by carrying out statistical precision analysis which compared the experimental results with those of the output of the models. From the results, the drying rate model showed 75 % agreement with the experimental results (i.e R2 value of 0.75), with a standard error of 3.27X10-5 and a variance of 5.37X10-8, the moisture content model interprets about 98.44 % of the experimental results with a standard error of 7.04X10-4 and the variance of 2.79X10-6, while the energy balance model showed about 99.0 % agreement with the experimental results with a standard error of 2.16X10-5 and a variance of 3.32X10-7.

Many researchers have carried out research on students’ academic performances in the University system, but there is dearth of information about models which focus on the relationship between students pre and post admission performances. This paper was therefore designed to model relationship between students’ pre and post admission performances. Information on pre admission performances (Olevel, Jamb and Post-Jamb results) and post-admission performances (100L – 400L results) of students’ in Statistics Department, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria was collected from students’ file. Correlation matrix and Canonical Correlation analysis were used to know the degree of relationship that exists between the pre and post admission performances. The principal component analysis was employed to reduce the multidimensional data. Scree plot was used to determine the spread of the trend of the components and bi plot was used to determine the degree of closeness of the students’ pre and post admission performances. There is no relationship between pre and post admission performances. Also, no strong relationship among pre admission performances, while the relationship among post admission performances is very high. Post admission performances are highly related to students’ CGPA. The proportion of variance accounted for by the first, second and third principal Components are 50.7542%, 16.5712% and 15.6224% respectively with cumulative proportion of 82.95%. The first, second and third components are chosen. The seven components were reduced to three. Post admission performances are closely related and stand as the determinant of students’ class of degree.

We are very happy to announce that from 4th January 2013, Mr.Neeraj Jindal has joined the team of Elixir Editorial Advisory Board. He will carry a special responsibility for dealing with manuscripts based on Electrical Engineering. Mr.Neeraj Jindal is currently working as Assistant Professor (ECE) Chartered Institute of Technology, Mount Abu (Rajasthan). The appointment of Mr.Neeraj Jindal as member Editorial Advisory Board strengthens the links and will make it easier for prospective authors to establish contact with the journal. Please send any expressions of interest to chiefeditor@elixirjournal.org. Sincerely Editor-in-Chief

This paper presents the new trends in code division multiple access techniques known as Optical CDMA Technology. I highlight those trends and features that are believed to be essential to the successful introduction of various OCDMA techniques in communication systems and data networks in near future. In particular, i elaborate on enabling technologies that are needed prior to full scale consideration of OCDMA in communication systems. I extend my discussion to various data network. It is believed that OCDMA once fully developed and matured will be an inseparable part of advanced optical communication systems and networks due to its various desirable features and functionalities, in not so distant future. Optical Code Division Multiple Access (OCDMA) is an optical processing system which allows multiple users to share the same bandwidth simultaneously without interfering with each other using unique optical codes. In this paper we present an in depth review on the new trends and the directions taken by the researchers worldwide in Optical Code Division Multiple Access (OCDMA) systems.

This study evaluated the presence of ochratoxin producing fungi and levels of ochratoxin A contamination in the most popular cassava food product (garri) in West Africa circulating in Ogun State, Nigeria. Results obtained revealed that the rate of total filamentous fungal contamination in all the sampled zones of Ogun State, Nigeria were not statistically significant (F= 0.327, P>0.05). For the black Aspergilli, the maximum contamination rate was 4.2 x 107 CFug-1 for a sample in Egba zone while the minimum concentration of 2.5x102 CFug-1 was obtained in a particular market in Remo zone. It was noted, that Aspergillus niger and Aspergillus carbonarius have the highest isolation rate of 21(24%) among the isolated filamentous fungi (F= 88.167, p< 0.05). 918 (92%) of the total samples of 1000 examined, contained detectable levels of OTA while samples from egba region have highest contamination rate (Fvalue = 3.504, P<0.005). These detectable levels found in our study satisfies the 0-5.0ppb recommended by the Codex Alimentarius Commission (1997). It can be concluded, that garri found in Ogun State are variously contaminated by different filamentous fungi, however black aspergilli remain the main ochratoxigenic moulds present in this staple food.

In this paper, we introduce and study some new separation axioms using the (1, 2)*-?gb-open sets in bitopological spaces.

Radiation is a volumetric phenomenon, and all solids, liquids, and gases emit, absorb or transmit radiation. However, radiation is usually considered to be a surface phenomenon for solids that are opaque to thermal radiation such as metals, woods and rocks since the radiation emitted by the interior regions of such material can never reach the surface, and the radiation incident on such bodies is usually absorbed within a few microns form the surface. Finned surfaces are used widely in industries, which due to their high temperature transferring heat by radiation is important. One of the this industry is space application, where the heat is transferred on in the mode of radiation. So, having the least material in very important in this industry. In this paper, Longitudinal fins with rectangular, triangular, concave, and convex profiles have been studied to establish the optimum dimensions based on the least material. The results showed that the concave parabolic has the best performance among other types of fins.

In this study, tin selenide was prepared at different ratios using tin and selenium pellets in glass tube filled with argon and then heated up to 350°C. The resulting materials were cut into ingots which were used in preparation of thin films by thermal evaporation. The evaporation was done using Edwards auto 306 coating unit. The chamber pressure was maintained at 5.0 x 10-5mbars during the film deposition. Thin films of tin-selenide produced using various ratios were characterized for optical properties and sheet resistance. The optical measurements were done using UV-VIS-NIR spectrophotometer Solid State 3700 DUV in the visible range (380-750nm) and the transmittance spectra data obtained was analyzed using the SCOUT software. The films with ratio of 1:1 showed the highest transmittance of 85% with a band gap energy obtained as 1.40eV. The electrical characterization measurements were carried out using a four point probe at room temperature (25°C) to obtain the sheet resistivity. The resistivity obtained for the films was 20.1?cm.

According to Betz, the maximum conversion efficiency of a wind turbine is 59.3%. But, the wind turbine works at efficiency of 25% to 35%. Hence, there is an opportunity to improve the efficiency of wind turbine. If, the efficiency of wind turbine is increased by at least 1%, it could turn into giant profits. Multiple nozzle system, therefore, if it is used, it increases the velocity of air, huge. The effect of multiple nozzle system is studied in the present article. The theoretical power coefficient and actual power coefficients of wind turbine are determined as part of the study. Few experiments were taken up earlier to increase wind speed using single nozzle system. But, multiple nozzle system is first ever, used in the history. The effect of conversion of heat energy into kinetic energy using multiple nozzle system is presented in this article. The design of multiple nozzle system obtained patents in India.

This paper emphasize on how parallelism can be applied in Data Analysis. In recent decades, where the large amount of data is produced by machines: software logs, cameras, microphones, RFIDs, etc. Creation speed rate of these data will increase exponentially with Moore’s Law. Saving or storing such amount of data is inexpensive and using some parallel processing methods, the data can also be investigated and mined effectively. So this article intends to debate about parallel programming procedures used in Data Analysis and Data Mining. The key motive for this parallelism is to make analysis more rapidly. This is generally attained by using multiple processors or multiple computers, execution dissimilar aspects of data analysis or mining, performing the tasks alongside and later consolidating the data into a single report.