Modification of Thermal Hydraulic Transient Models for the Miniature Neutron Source Reactor

A modified Miniature Neutron Source Reactor (MNSR) model dealing with transient thermal hydraulic problem is presented. The model based on lumped parameter method is adopted in this work to numerically solve a system of coupled algebraic and differential equations governing heat transfer in MNSR, using MATLAB solver for variable order method in stiff differential equations and Differential-Algebraic equations, coupled with Maple soft. The simulated results obtained from the model were generally in agreement when compared with reactor operation data recorded from 0 to 270 minutes during experiments. Radiating energy of Fuel and clad and heat transferred at the gap or clearance were taken in to account. Fuel and clad temperatures as well as various temperatures at different sections of the reactor were predicted with the model, in addition to the effect of the installed chiller on the reactor coolant

Comparison of ascorbic acid content of some selected fresh and dried tropical vegetables

Ascorbic acid (Vitamin C) was determined in four different tropical vegetables (Cucumber, Cabbage, Spinach and Tomatoes) sourced from Yankaba market, Kano state. Colorimetric method was used for the  determination. The ascorbic acid content in the cucumber, cabbage, spinach and tomatoes ranged from 51.67mgL-1 to 395.45mgL-1. Tomatoes were found to have the highest concentrations (395.45mgL-1) while cucumber has the lowest (181.82mgL-1 for the fresh and 60.00mgL-1 and 51.67mgL-1 respectively) for the dried vegetables. The deficiency of ascorbic acid is believed to result in scurvy, a disease characterized by spongy and sore gum, loose teeth, anaemia, swollen joint, fragile blood vessels. Frequent intake, therefore of these vegetables rich in vitamin C (especially tomatoes) will help prevent these problems in human being. This indicated that although the vegetables are rich in ascorbic acid content, their dried forms have grossly inadequate amount to ensure the provision of required dietary intake (RDI) of vitamin C for humans.Keywords: Ascorbic acid, Comparison, Vegetables, Vitamin

Multiclass Sequential Feature Selection and Classification Method for Genomic Data

This paper presents an efficient multiclass sequential feature selection and classification (mk-SS) method using gene expression signatures. The development of this method employs 10-fold cross-validation to ensure stability. The efficiency of this method is assessed through the misclassification error rate and some other performance measures. The performances of the mk-SS were compared with the classification results of the Support Vector Machines (SVM) over five published multiclass microarray datasets. The results showed that the mk-SS method efficiently selects the informative gene biomarkers for proper classification of the biological groups of the tissue samples. This method competes favourably with SVM in terms of prediction accuracy while it outperforms the SVM in 80% of cases considered. The quality of the features selected by mk-SS algorithm was validated by hybridizing the feature selection scheme of the mk-SS into the standard SVM algorithm which significantly improves the predictive power of the standard SVM method. This work has shown that classification of various cancer type using gene expression profiles is feasible especially when the endpoints are of multi-category. Keywords: k-SS, mk-SS, Support Vector Machines, Microarray, Misclassification error rat

Environmental and Health risks Associated with Dental Waste Management: A Review

Proper management of dental waste is a crucial issue for maintaining human health and the environment. The waste generated in the dental clinics has the potential for spreading infections and causing diseases, so improper disposal of these dental wastes can cause harm to the dentist, the people in immediate vicinity of the dentist, waste handlers, general public and the environment through production of toxins or as by-products of the destruction process. Staff that provide dental healthcare ought to be aware of the proper handling and the system of management of dental waste used by different dental hospitals. The method of investigation adopted in the paper involved a desk study in which documents and records relating to dental waste handling were studied to obtain background information on existing dental waste management in Nigeria other countries of the world are also mentioned as examples.  Additionally, information on generation, handling, segregation, risk associated during handling and treatment of dental medical waste were sought in order to determine the best method for safe disposal. This article provides dentists with the information they need to properly dispose of mercury and amalgam waste, and provides suggestions for managing the other wastes that result from the day-to-day activities of a dental office such as: used X-ray fixers and developers; cleaners for X-ray developer systems; lead foils, shields and aprons; chemiclave/chemical sterilant solutions; disinfectants, cleaners, and other chemicals; and, general office waste. Additionally, this study may be beneficial for authorities and researchers of developing countries to work towards improving their present Dental waste management system. Keywords: Clinic, dental, disposal, environment, waste management

Assessment of natural radionuclides in rivers of Pahang State Malaysia

Investigations were conducted to determine the radionuclide concentration levels in the major rivers in Pahang state, Malaysia. Since the rivers are the main sources for water supply in the state, it is important to measure natural radionuclide concentrations in the rivers. Seventeen water samples were collected from major rivers in Pahang state. The concentration of uranium, thorium and potassium were analyzed using inductively coupled plasma mass spectrometer (ICP-MS). The samples were found to contain permissible levels of radionuclides with a mean activity concentrations of uranium, thorium and potassium found to be 8.49 ± 0.34 mBq L-1, 1.74 ± 0.27 mBq L-1and 77.85 ± 0.96 mBq L-1respectively. The ratio between thorium and uranium concentration is found to be 3:4 due to the higher solubility of uranium than thorium in water. Radionuclide concentrations obtained were compared with the terrestrial gamma radiation dose rate measured around the area. A good relation was observed between uranium and thorium concentrations with gamma dose rate obtained around the area while no relation was found between the potassium concentrations with gamma dose rate. Significance of the results obtained is discussed

Accuracy of Phy-X/PSD Software Compared to XCOM in the Determination of Mass Attenuation Coefficient of Glass Systems

Phy-X/PSD and XCOM are two software programs used for computations in radiation shielding and nuclear energy research. This study aims to compare the accuracy of Phy-X/PSD with that of XCOM in the determination of mass attenuation coefficient (MAC) of glass systems. The MAC values of 60B2O3-(40-x)BaO-xBi2O3, 50BaO-xBi2O3-(50-x)borosilicate glasses, and xTeO2-(70-x)ZnF2-25AsO3-5Sm2O3 glass systems at 0.662 MeV, 1.172 MeV and 1.332 MeV were determined using Phy-X/PSD. The mean absolute error (MAE) was determined and compared with MAE from experimental data and from XCOM. The results showed no significant difference between the MAC means obtained from the three data sets. However, single factor ANOVA test shows that the p-values for the MAC means are 0.344, 0.918 and 0.239 approximated to 3 d.p at 0.662 MeV, 1.172 MeV, and 1.332 MeV respectively and the variance was highest in the experimental result, followed by Phy-X/PSD, and least in the XCOM results. It could be concluded that both software programs can be used for radiation shielding computations, although result from Phy-X/PSD may have relatively more outliers compared to XCOM

Investigating total entrepreneurial activity and entrepreneurial intention in Africa regions using fuzzy-set qualitative comparative analysis (fsQCA)

This study offers a novel evaluation of the conditions for Total Entrepreneurial Activity (TEA) and Entrepreneurial Intention (EI) across 59 Sub-Saharan African regions. The analysis employs fuzzy-set Qualitative Comparative Analysis using Global Entrepreneurship Monitor (2013) survey data using five condition variables, measuring regional-level entrepreneurial attitudes and perceptions, including education level, considered against TEA and EI. This novel regional contribution identifies diversity between African countries and regions for entrepreneurial activities and its drivers, with several groups identified. This highlights a requirement for future research encompassing further countries and regions in African, and also multi-year studies that can track these issues longitudinally. The study informs knowledge and practice regarding entrepreneurial behaviour across African regions. Through examination of the different combinations of condition variables, across causal recipes, it provides understanding of variations in the socio-cultural drivers of entrepreneurial activity between regions, groups of regions, and countries, for TEA and EI

Development of novel multiplex microsatellite polymerase chain reactions to enable high-throughput population genetic studies of Schistosoma haematobium

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