13 research outputs found
Using asymptotic iteration method (AIM) for solving differential equations: case study of vibrational states of diatomic molecule
This paper discusses the new computational technique referred to as the asymptotic iteration method (AIM), and presents numerical computations of exact energy eigenvalues of the Schrödinger equation assuming the Morse potential for some diatomic molecules. The method is used to compute the numerical energies of bound vibrational levels of the 7Li2, H2, and N2 diatomic molecules in the 1Σu+, 11Σu+ and 3Σu+ electronic states
Electronic band structure and optical properties of titanium dioxide
In this work the Fritz-Haber Institute ab initio Molecular Simulation (FHI-aims) code was used to investigate and obtain the band energies and linear dielectric functions of the three naturally occurring phases of TiO2 (Rutile, Anatase and Brookite). The exchange-correlation interactions are treated by the PBE. The results of the band gap were obtained to be 1.76 eV for Rutile, 2.07 eV for Anatase and 2.33 eV for Brookite with Rutile having a direct band gap and indirect band gaps for both Anatase and Brookite. The obtained band gaps are in agreement with other theoretical work, especially on the rutile phase. The linear dielectric function was calculated using Random Phase Approximation (RPA) where the average static dielectric function at ω= 0 was obtained as 5.61 for Rutile TiO2, 4.29 for Anatase TiO2 and 2.23 for Brookite TiO2
Computations of the band structure and linear optical properties of methylammonium bismuth bromide and methylammonium galluim bromide using FHI-aims Code
Ab initio calculations for the Linear Macroscopic Dielectric analyses of CH3NH3BiBr3 and CH3NH3GaBr3 (having 8.33% dopant replacement percentage each) as possible replacements for the Lead based perovskite CH3NH3PbBr3 were done in this work using Perdew–Burke–Ernzerhof functional of Density Functional Theory as implemented by FHI-aims Code. Optimized lattice constants were calculated for CH3NH3BiBr3 and CH3NH3GaBr3 to be 9.10 Å and 8.27 Å respectively. The Lowest Unoccupied Molecular Orbital (LUMO), Highest Occupied Molecular Orbital (HOMO) and calculated band gap, Band Structure and Density of States (DOS) plots were made to analyse the band structures of these crystals and they were found to be metallic with a band gap of 0.00018636 eV and 0.00022286 eV for CH3NH3BiBr3 and CH3NH3GaBr3 respectively. The imaginary and real parts of the inter-band and intra-band contribution to the linear dielectric tensor within the e imagi Random Phase Approximation (RPA) of the optical properties of these perovskites were calculated and an average dielectric tensor of 3.1209467 and 2.789173 was found for CH3NH3BiBr3 and CH3NH3GaBr3 respectively. From the absorption data and dielectric tensor components calculated, both materials have an average absorption peak at frequency of 16.5373nm at 1.006567 MeV, 16.2040nm at 1.227600 MeV respectively, across all cubic planes
Prediction of Fatigue Life of Fiber Glass Reinforced Composite (FGRC) using Artificial Neural Network
The present work studies the mechanical properties of composite materials, experimentally and analytically, that are fabricated by stacking 4-layers of fiberglass reinforced with polyester resin. This plies are tested under dynamic load (fatigue test) in fully reversible tension-compression (R=-1) to estimate the fatigue life of the composite where fatigue performance of fiberglass reinforced composed is an increasingly important consideration especially when designing wind turbine blades. In order to predict fatigue life (Number of cycles to failure), conventional analytical techniques are used in the present work. In addition, Artificial Neural Network (ANN) is a reliable and accurate technique that is used for predicting fatigue life. The used networks are; Feed Forward Neural Network (FFNN), Generalized Regression Neural Network (GRNN) and Radial Bases Function Neural Network (RBFNN). Based on the comparison of the results, it is found that the ANN techniques are better than conventional methods for prediction. The results shows that (RBNN2), where stress load and angle of orientation are input to the network and number of cycles to failure as output, is an efficient tool for prediction and optimization the fatigue life of fiberglass reinforced composite
Pattern of Blood Pressure in Adolescents
Background: Out of office blood pressure has been shown to be a better representation of an individual’s blood pressure. This prospective school-based study was designed to investigate the normal range of out of office blood pressure and its associated factors in adolescents.Methods: A total of 718 adolescents (309 males and 409 females) were recruited and their blood pressures taken 6 times over 2 days. The prevalence of hypertension and the relationship between blood pressure level and height, body mass index, age and socio-economic status were determined. Results: The mean systolic blood pressures for males and females were 109.5 ± 13.9, and 112.2 ± 13.0 mmHg, respectively [p=0.01], while the mean diastolic pressures were 71.4 ± 9.2 and 74.19 ± 9.6 mmHg for the males and females, respectively [
Phytochemical and in vitro antiplasmodium activities of leaf extracts of Cassia nigricans Vahl. (Caesalpinaceae)
The study was aimed at evaluating the phytochemicals, acute toxicity and in vitro antiplasmodium activity of aqueous and chloroform leaf extracts of Cassia nigricans using the basic phytochemical screening, Lorke’s and Candle Jar methods. Steroid glycosides, reducing sugars and alkaloids were detected in both extracts, while saponins and flavonoids were only detected in the aqueous extract. The median lethal dose (LD50) of the aqueous leaf extractwas found to be 471.17mg/kg. The in vitro antiplasmodium screening showed that both extracts have antiplasmodium activity; with chloroform extract having the highest activity at the concentration of 2, 3 and 4 mg/ml which was statistically significant (P<0.05) in comparison with the positive control. The chloroform extract had the most potent half maximal inhibitory concentration (IC50)value of 0.60 mg/ml. It can be concluded that C. Nigricans possess strong antiplasmodium activity and this may accounts for its use in traditional medicine in the management of malaria.Keywords: Acute toxicity, antiplasmodium, malaria, phytochemicals and traditional medicin
Agriculture and development policy A critical review of Nigerian experience
SIGLEAvailable from British Library Document Supply Centre- DSC:9117.4(TRP--84) / BLDSC - British Library Document Supply CentreGBUnited Kingdo
PAIN MEDICINE Intraoperative Ketamine Reduces Perioperative Opiate Consumption in Opiate-dependent Patients with Chronic Back Pain Undergoing Back Surgery
ABSTRACT Background: Ketamine is an N-methyl-D-aspartate receptor antagonist that has been shown to be useful in the reduction of acute postoperative pain and analgesic consumption in a variety of surgical interventions with variable routes of administration. Little is known regarding its efficacy in opiatedependent patients with a history of chronic pain. We hypothesized that ketamine would reduce postoperative opiate consumption in this patient population. Methods: This was a randomized, prospective, doubleblinded, and placebo-controlled trial involving opiate-dependent patients undergoing major lumbar spine surgery. Fifty-two patients in the treatment group were administered 0.5 mg/kg intravenous ketamine on induction of anesthesia, and a continuous infusion at 10 g kg ĎŞ