Gamma Ray Spectrometric Analysis of Naturally Occurring Radioactive Materials (NORMS) in Gold Bearing Soil using NaI (Tl) Technique

In this work, the radioactivity in the gold bearing samples collected from the artisanal mining sites in Birnin Gwari Local Government Area, Kaduna State have been determined, experimental measurements of 226Ra, 232Th and 40K activities concentration in the gold bearing samples have been carried out using a NaI(Ti) gamma ray spectrometer. The measured activity concentration for 226Ra have been found to lie in the specific ranges from 1.0545±0.4983Bq/Kg to 3.8355± 0.3476Bq/Kg while the  mean concentration is 2.383±0.4415Bq/Kg for 232Th, the activity concentration ranges from 9.3501±1.0260Bq/Kg to 66.7047±0.5700Bq/Kg, while the mean activity concentration of 232Th is 32.3644±9.3440Bq/Kg, for 40K,the activity concentration ranges from 120.9953±6.5319Bq/Kg to 815.8631±10.504Bq/Kg, while the mean activity concentration is 383.7924±72.5436Bq/Kg. The mean absorbed dose rate in the study area is 35.7334nGy/hr; while the mean annual effective dose rate is 0.032mSv/year which is lower when compared with tolerable limits of 1mSv/year. Keywords; Natural Radionuclides,Aactivity Concentrations, Absorbed Dose

On The Experience Of The Arab Open University With The Standard Deviation Method

The Arab Open University (AOU) has adopted the standard deviation method (SDM) as a grading system in replacement of a fixed scale. Adopting SDM was intended to remedy a problem that has resulted from discrepancies between AOU's graduation requirements and those of its partner, UK Open University. This paper aims mainly at investigating whether SDM has served the purpose for which it was selected. A data set of the final letter grades of students enrolled in 18 licensed courses from UK-OU at Kuwait branch was used. These letter grades were analyzed in comparison with the letter grades that would have been assigned to students had the fixed grading scale been utilized. The results of the comparative analysis revealed that SDM resulted in benefiting 39.4% of all students and lowering the letter grades of 10.4% of the students. Despite its positive results, SDM has not contributed significantly to remedying the problem in question. Thus, a case for withholding the D grade while continuing with using SDM was presented

Effect of dried and extrudate of bitter gourd fruit on epithelial microflora in raw chicken legs meat

Plants have been used recently to eliminate bacterial growth in food products. This study was undertaken to test the in vitro sanitizing effect of crude extract from bitter gourd (BG) fruit on the growth of native microorganisms in raw chicken leg meat. Hot air dried BG and extrudate extracts at 1% concentration and exposure times of (5, 10 and 15 min) were used to treat the samples using dilution method. Results showed that BG extrudate had a slightly stronger bactericidal activity against the microflora than the B.G. hot air drying treatment, especially, on E. coli at all exposure time. Overall, there is no significant difference between the treatments; Total Plate Count (TPC), Escherichia coli, Bacillus cereus, Staphylococcus aureus. The best reduction time of microflora by hot air dried extract was at (15 min) except for B. cereus was at (5 min) and for extrudate extract was at (5 min) except for E. coli was at (10 min). In conclusion, bitter gourd extract could be used as an important natural sanitizer for rinsing raw food matrials such chicken meat

Physicochemical and sensory characteristics of palm olein and peanut oil blends.

Blending is the simplest method used to modify oils and fats for improved functionality. Blends of palm olein (PO) (90, 80, 70 and 60% v/v) with peanut oil (PnO) (10, 20, 30 and 40% v/v) were made and changes in their physicochemical and sensory characteristics were determined. Changes in physicochemical characteristics, fatty acid composition (FA), triacylglycerol (TAG) profile, thermal behavior and sensory quality were determined. Results showed that with increasing amounts of PnO (from 10 to 20, 30 and 40%) coupled with decreasing amounts of PO (from 90, 80, 70 and 60%) in the blends, the degree of unsaturation increased and a pleasant nutty flavor was imparted in the blends. The FFA content increased from 0.36% (90 PO:10 PnO) to 0.90% (60 PO:40 PnO). Blending altered the FA composition with major changes occurring in the percentages of palmitic and linoleic acids. These changes in FA composition caused a significant change in trilinolein (LLL), dioleoyl-linoleoyl- glycerol (OOL) dipalmitoyl-3-linoleoyl glycerol (PPL) and dipalmitoyl-3-oleoyl glycerol (PPO) in the blends. The melting and crystallization temperatures gradually shifted towards lower temperature from 10.22 to 9.33, 8.26 and 8.25ºC and from -4.48 to -4.73, -5.22 and -25.37ºC, respectively, with increasing PnO and decreasing PO percentages. Sensory evaluation of banana chips fried with the oil blends showed a high acceptability for all the blends by the panelists, which was indicated by the high scores for all the sensory attributes tested and the overall acceptability

The Effect of Varying Soot Concentration and Relative Humidity on Visibility and Particle Size Distribution in Urban Atmosphere

This research used extracted extinction coefficients and common mode radii of urban aerosols to carry out visibility simulations at corresponding spectral wavelengths from 0.4-0.8µm from the improved version of the Optical Properties of Aerosols and Clouds (OPAC 4.0) data at eight relative humidities(RH) (0%, 50%, 70%, 80%, 90%, 95%, 98% and 99% RH). Five models of the urban aerosols used comprised of insoluble (INSO), Water-soluble (WASO) and Soot (Black Carbon). From the average concentration set up by OPAC 4.0, the concentrations of the Soot (Black Carbon) were varied by external mixing. The Angstrom exponent (α), the curvature (α2) and the urban atmospheric turbidity (β) were obtained from the regression analysis of the first and second order polynomial of Kaufman’s representation of the Koschmieder equation for atmospheric visibility. The mean exponents of the aerosol size growth curve (µ) were determined from the aerosol effective hygroscopic growth (geff) while the humidification factors (γ) were determined from the visibility enhancement factors f(RH,λ). With µ and γ, the mean exponents of aerosol size distributions (υ) were determined for all the models. It was observed that at varying Soot (Black Carbon) concentrations and RH there were non-linear relationships between them and visibilities. The values of α > 1 showed the presence of fine mode particles from the WASO part of the aerosol mixture and α2 being positive indicated bimodal aerosol particle distributions. Additionally, visibility deterioration is predicted because of the increase in turbidity (β) with the variation of Soot and RH

Engineering the Production of Major Catechins by Escherichia coli Carrying Metabolite Genes of Camellia sinensis

A mimicked biosynthetic pathway of catechin metabolite genes from C. sinensis, consisting of flavanone 3 hydroxylase (F3H), dihydroflavonol reductase (DFR), and leucoanthocyanidin reductase (LCR), was designed and arranged in two sets of constructs: (a) single promoter in front of F3H and ribosome-binding sequences both in front of DFR and LCR; (b) three different promoters with each in the front of the three genes and ribosome-binding sequences at appropriate positions. Recombinant E. coli BL (DE3) harbouring the constructs were cultivated for 65 h at 26°C in M9 medium consisting of 40 g/L glucose, 1 mM IPTG, and 3 mM eriodictyol. Compounds produced were extracted in ethyl acetate in alkaline conditions after 1 h at room temperature and identified by HPLC. Two of the four major catechins, namely, (−)-epicatechin (0.01 ) and (−)-epicatechin gallate (0.36 mg/L), and two other types ((+)-catechin hydrate (0.13 mg/L) and (−)-catechin gallate (0.04 mg/L)) were successfully produced

Kinetic and Thermodynamic Studies of Chromium Ion Adsorption Using Chitosan from Mussel Shell

A study was carried out to investigate the removal of chromium (VI) ion from chromate solution using deacetylated chitin extracted from mussel shell. Mussel shells were obtained from Gubi dam in Bauchi, Nigeria and chemical method was used to extract chitin and then chitosan from these shells. A batch adsorption study was used to generate data for kinetic modelling. Out of the four kinetic models tested, the adsorption process was found to follow the pseudo-second order kinetic model with an R2-value of 0.9997; The process was physical with a free sorption energy of 0.224 kJ/mol. Also, the enthalpy of adsorption was -67.295 kJ/mol K and the Gibbs free energies were all negative, thus the process is spontaeneous and exothermic. Keywords: Kinetic, Chitosan, Mussel, Chromium, Adsorption, Thermodynami