A first-principles study of helium storage in oxides and at oxide--iron interfaces

Density-functional theory calculations based on conventional as well as hybrid exchange-correlation functionals have been carried out to study the properties of helium in various oxides (Al2O3, TiO2, Y2O3, YAP, YAG, YAM, MgO, CaO, BaO, SrO) as well as at oxide-iron interfaces. Helium interstitials in bulk oxides are shown to be energetically more favorable than substitutional helium, yet helium binds to existing vacancies. The solubility of He in oxides is systematically higher than in iron and scales with the free volume at the interstitial site nearly independently of the chemical composition of the oxide. In most oxides He migration is significantly slower and He--He binding is much weaker than in iron. To quantify the solubility of helium at oxide-iron interfaces two prototypical systems are considered (Fe|MgO, Fe|FeO|MgO). In both cases the He solubility is markedly enhanced in the interface compared to either of the bulk phases. The results of the calculations allow to construct a schematic energy landscape for He interstitials in iron. The implications of these results are discussed in the context of helium sequestration in oxide dispersion strengthened steels, including the effects of interfaces and lattice strain.Comment: 13 pages, 10 figures, 4 table

Effects of some heavy metal pollutants on fertility characteristics of an irrigated savannah Alfisol

This research was conducted on the irrigated soils along the banks of the Jakara River within the metropolitan Kano and its suburb. Soil samples were collected between latitude 11o59’ and 12o 08’N and longitude 8o34’ and 8o 42’E at an altitude of 486.5m. The study investigated the effects of some heavy metals (Cd, Pb and Cu) on the fertility indices of the soil. Grid sampling was employed in which 100m2 of land was randomly selected in each of two sampling areas and was divided into ten equally sized grid cells of 10m2. Samples were analyzed for lead, cadmium and copper concentrations as well as fertility related parameters such as CEC and basic cations. Data obtained was subjected to correlation analysis using the Pearson moment correlation coefficient technique. The mean values of the heavy metals and the fertility indices are considered for the two sampling areas in bulk. Significantly positive correlation was found to exist between CEC, organic matter, nitrogen and phosphorus at P = 0.01. Significantly positive correlation was also found to exist between lead and potassium; lead and phosphorus; nitrogen and magnesium and copper and phosphorus. The quality of the soil for production is not immediately under threat especially with the very low mean values of the pollutants and the lack of significant effects they exert on many of the fertility indices determined

Analisis Segmen Pasar Dan Perilaku Nasabah Bank Syariah: Kajian Hukum Islam Terhadap Produk Hsbc Amanah Indonesia

The purpose of this research is for identifying market segment and customer behavior toward Islamic banking and its marketing implications in all regions of DKI Jakarta. The analytical tools applied are analysis of cluster, factor and descriptive. The result of this research for segmentation aspect showed the characteristics and size of each market segment of Islamic banks. The market segment consists of syariah loyalist, floating mass and conventional loyalist. From this research, floating mass segment is the most potential segment due to its market size compared to syariah loyalist and conventional loyalist segments.DOI: 10.15408/aiq.v4i2.253

Using Regression Model Data to Predicts the Outcomes of Pregnancies (A Case Study of Dutse General Hospital)

A logistic regression model has been developed previously to predict the outcome of pregnancies. This model was based on the human chorionic gonadotropin (HCG) ratio. As women present at earlier gestation to early pregnancy units (EPU) the number of women diagnosed with early pregnancy of unknown location increases. Some of these women will have an ectopic pregnancy (EP) and this group in the population poses the greatest concern. Data were gathered in a single early pregnancy unit from all women with an early pregnancy, were this data set was divided into a model building. We developed regression model with expert information using this data set to predict the outcome of pregnancies. Keywords: chrionic gonadotropin, gestation,embrayo,pregnancy