Geological influence on the activity concentration of terrestrial radionuclides 226Ra, 232Th and 40K in the Jos Plateau,Nigeria

The Jos Plateau has been reported to have elevated levels of natural background radiation. A few earlier studies have measured the levels of natural radioactivity for specific locations in the area. Our interest is to investigate how geology of the study area influences the activity concentrations of natural radionuclides. Thus, the activity concentrations of terrestrial radionuclides in soil samples collected across the geological formations of the Jos Plateau were determined by gamma spectrometry technique. The mean activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K were found to exceed their corresponding world reference values of 35, 40 and 400?Bq?kg^?1, respectively. Data were compared using statistical methods, analysis of variance (ANOVA) and post hoc tests. The results revealed in some instances significant influences of geological types on the activity concentrations in the area. The spatial distribution maps of activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K were geostatistically interpolated by ordinary Kriging method using ArcGIS software.     

A network of congruences on an ample semigroup

Semigroup Forum - For an admissible congruence $$\gamma $$ on an ample semigroup S, the minimum admissible congruence $$\gamma _t$$ whose trace is $$\mathrm {tr}\gamma $$ has been determined by the...     

Biological Potentials and Phytochemical Constituents of Raw and Roasted Nigella arvensis and Nigella sativa

Nigella species are widely used to cure various ailments. Their health benefits, particularly from the seed oils, could be attributed to the presence of a variety of bioactive components. Roasting is a critical process that has historically been used to facilitate oil extraction and enhance flavor; it may also alter the chemical composition and biological properties of the Nigella seed. The aim of this study was to investigate the effect of the roasting process on the composition of the bioactive components and the biological activities of Nigella arvensis and Nigella sativa seed extracts. Our preliminary study showed that seeds roasted at 50 °C exhibited potent antimicrobial activities; therefore, this temperature was selected for roasting Nigella seeds. For extraction, raw and roasted seed samples were macerated in methanol. The antimicrobial activities against Streptococcus agalactiae, Streptococcus epidermidis, Streptococcus pyogenes, Candida albicans, Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, and Klebsiella oxytoca were determined by measuring the diameter of the zone of inhibition. The cell viability of extracts was tested in a colon carcinoma cell line, HCT-116, by using a microculture tetrazolium technique (MTT) assay. Amino acids were extracted and quantified using an automatic amino acid analyzer. Then, gas chromatography–mass spectrometry (GC–MS) analysis was performed to identify the chemical constituents and fatty acids. As a result, the extracts of raw and roasted seeds in both Nigella species showed strong inhibition against Klebsiella oxytoca, and the raw seed extract of N. arvensis demonstrated moderate inhibition against S. pyogenes. The findings of the MTT assay indicated that all the extracts significantly decreased cancer cell viability. Moreover, N. sativa species possessed higher contents of the measured amino acids, except tyrosine, cystine, and methionine. The GC–MS analysis of extracts showed the presence of 22 and 13 compounds in raw and roasted N. arvensis, respectively, and 9 and 11 compounds in raw and roasted N. sativa, respectively. However, heat treatment decreased the detectable components to 13 compounds in roasted N. arvensis and increased them in roasted N. sativa. These findings indicate that N. arvensis and N. sativa could be potential sources of anticancer and antimicrobials, where the bioactive compounds play a pivotal role as functional components.     

Mini-review on the synthesis of Biginelli analogs using greener heterogeneous catalysis: Recent strategies with the support or direct catalyzing of inorganic catalysts

The present review covers the summary of recent progress in designing and developing Biginelli reaction strategies particularly the greener strategies with higher yields, short times and simple work-up, in which the inorganic materials such as alumina, silica gel or zeolite directly or having doped with other reagents were used as catalysts for such a type of transformations. Moreover, several aspects and available references of heterogeneous catalysis using inorganic catalysts in promoting reactions are provided briefly in this review. There is also a concise account covering the better alternative syntheses and some of improved and robust protocols of biginelli reaction for the preparation of dihydropyrimidin-2(1H)-one/thiones analogs.     

Quasi-adequate semigroups II

In this paper we describe the least fundamental adequate good congruence on an arbitrary typeW semigroupS as well as the largest superabundant full subsemigroup ofS and the largest full subsemigroup ofS which is a band of cancellative monoids. TypeW semigroups were introduced in [3] and a structure theorem for those semigroups was obtained. Here we introduce weak typeW semigroups by replacing the idempotent-connected property in typeW by one of its consequences. A structure theorem is obtained for such semigroups.     

A radioxenon detection system using PIPS and CZT

Journal of Radioanalytical and Nuclear Chemistry - This paper introduces and describes the initial characterizations of a prototype beta-gamma coincidence detection system that utilizes a PIPSBox...