Ground-State Energy Calculation of Helium Atom Using Quantum Monte Carlo CASINO-Code

We report an improved variational Monte Carlo (VMC) calculation of the ground-state energy of the helium atom, using quantum Monte Carlo (QMC) CASINO – code. The VMC ground-state energy is studied with a single determinant Slater-Jastrow trial wave-function formed from Hartree-Fock orbitals. The optimization of orbitals improved the agreement between the variational Monte Carlo and recent experiment. The calculated ground-state energy result is –2.903692762 ± 0.000023 a.u., which is in good agreement with the most recent experimental value –2.903693775 a.u. obtained by Bergeson et al. A more accurate trial function for importance sampling and the use of Jastrow–function combine to yield a ground-state energy which is 5 significant figures more accurate than that of previous quantum Monte Carlo calculations. Keywords: CASINO code, QMC, VMC, Helium atom, Reblocked-standard-erro

Insight from the study of acidity and reactivity of Cr2O3 catalyst in propane dehydrogenation: a computational approach

By converting low-value commodity fuels into high-value products, like polymer precursors, chemical and other intermediates, the dehydrogenation of light paraffin (such as ethane and propane) into olefins, can add significant value to the refining processes that generate propane. In this study, the parameterised method 3 (PM3) approximation of semi empirical theory was employed to study the acidity and reactivity of chromium (III) oxide catalyst in the dehydrogenation of propane into propylene. Ammonia and pyridine were used computationally as molecular probes for the evaluation of the Lewis acidity of the catalyst sites. The propane adsorption and dissociation activation energies were also evaluated. The study showed that the chromium sites are highly acidic and reactive compared to the oxygen sites. In particular, the study showed that the chromium site is the main active site in the promotion of propane dehydrogenation into propylene, over chromium (III) oxide catalyst. Keywords: Acidity, Reactivity, Dehydrogenation, Propane, Chromium

Understanding the key competencies of market-ready building surveying graduates from employers’ perspectives

Purpose: This study investigates the various competencies a graduate should hold to prepare them for graduate building surveying roles from employers’ perspective. Design/Methodology: The study employs a sequential exploratory mixed-method approach by informing a quantitative study with the finding from a qualitative study. Findings: Based on exploratory factor analysis, the study found that 13 essential competencies are valued by the employers when recruiting building surveying graduates, as they are requisites for effective job performance. Personal management skills, technical surveying knowledge, and knowledge of RICS standards are the essential competencies based on the level of variance extracted by the three components. Other competency categories include client management skills, being goal-driven and self-motivated, optimistic personality traits, strong mental resilience, building maintenance and management knowledge, and time management skills, among others that are explained in the paper. Originality/Value: The essential competencies were dependent on maintaining a balance between knowledge, skills and personality-based competencies. Measures and approaches for gaining the essential competencies, as well as their level of significance, are further discussed. The study will be of significant benefits to employers of graduate building surveyors, academic institutions that are seeking to improve their graduate employability, as well as students that are preparing for the world of work

Growth performance, haematological and biochemical study of Clarias gariepinus (Burshell) fingerlings fed formlulated Rana galamensis (Galam) meals

A 56-­‐day feeding experiment involving Clarias gariepinus fingerlings was conducted to investigate the growth response, serum and biochemical parameters of the fingerlings to formulated feed from Rana galamensis at 0%, 10%, 20%, 30% and 40% inclusion levels. 180 fingerlings were divided into 5 treatment groups containing 36 fingerlings and each group was further replicated 3 times. A significant difference (P<0.05) was established in the growth parameters determined in the C. gariepinus fingerlings fed with the four frog formulations, namely, final weight, total weight, and mean feed gain, mean weight gain and feed conversion ratio The 40% R. galamensis ration elicited higher growth values than all other rations. Similarly, significance difference (P<0.05) was established in the serum (Total protein, Albumin and Cholestreol) and biochemical (Na+. K+ and HCO3 -­‐) parameters determined in the blood samples collected from the fingerlings fed with the four frog formulations. The increasing values observed in the growth factors, serum and biochemical parameters of the fingerlings when increasing level of R. galamensis protein was incorporated into the fish diet is an indication that the formulated feed can serve as growth promoter as well as rich sources of mineral supply to the fish; hence, a potential protein source for aquacultural practices

Evaluation of the Efficacy of African Basil (Ocimum gratissimum) Leaf for Disinfecting Well - water obtained from Ekiti State, Nigeria

The demand for potable and affordable water led to comparative research of the efficacy of Ocimum gratissimum Leaf (OGL) extract by collecting well water and treated with OGL extract. Both treated and untreated samples were subjected to physiochemical and bacteriological examinations. Data obtained showed that the pH and feacal coliform counts ranged from 6.17 to 6.74 and 0 to 192 CFU/100 mL for well water sample A; 6.56 to 7.24 and 0 to 118 CFU/100 mL for well water samples B; 6.81 to 7.79 and 0 to 75 CFU/100 mL for well water samples C respectively. The OGL extract includes various bioactive components (i.e. steroids, tannins, etc) according to the phytochemical tests. The first feacal coliform count was above the allowed range (i.e. >50 CFU/100 mL) and the pH value tended to be acidic (6.5), with a colour of >15 H.U. and an unclear (brownish) appearance. The Coliform count was lowered with each dosage of OGL extract until it reached zero count after 24 hours’ contact time at an optimum dosage of 5 mL and the total bacteria counts were gone. The beneficial influence (s) from this study confirms the disinfectant potential of OGL extract for well water treatment

Chemical analysis of Ricinus communis L. (Euphorbiaceace) seed kernel extract and its in-vitro toxicity in two Podagrica Species (Coleoptera: Chrysomelidae)

Since synthetic pesticides are associated with many toxicological problems against untargeted subjects, pesticides from botanical sources become a better option. This study obtained R. communis seed kernel extract (RCSKE) through acidified aqueous extraction. The extract was screened using Infra red (IR) and Ultraviolet (UV) spectroscopy, High-Performance Liquid Chromatography (HPLC) and Cass Chromatography (GC) for bioactive agents. In-vitro effects of RCSKE, chlorpyrifos (CPF) and cypermethrin (CYPER-M) on superoxide dismutase (SOD), Catalase (CAT), acetylcholinesterase (AChE) and Carboxylesterase (CE) activities in Podagrica sjosdteti and Podagrica uniforma were determined spectrophotometrically. The IR and UV of RCSKE majorly depict the presence of aromatic ring, ethylenic bond, carbonyl bond, hydroxyl and carboxylic groups. The HPLC and GC majorly show the presence of ricinoleic acid, ricinine and ricin. The RCSKE, CYPER-M and CPF increased CAT activity in P. sjosdteti, but reduced it in P. uniforma. The RCSKE and CYPER-M significantly reduced SOD, and elevated AChE activities in P. sjosdteti. The IC50 values of RCSKE, CYPER-M and CPF against CE activity in P. sjosdteti were IC50 = 2.66 µg/ml, IC50 = 2.37µg/ml and IC50 = 2.65 µg/ml), respectively, while that of RCSKE against P. uniforma was IC50 = 2.49 µg/ml. This study suggests that the extract of Ricinus communis seed kernel contains bioactive substances, capable to inhibit the antioxidant, acetylcholinesterase and carboxylesterase enzymes in Podagrica species flea beetles, comparable to commercial pesticides, Cypermethrin and Chlorpyrifos. Key words: Ricinus communis, Chemical screening, Podagrica sjosdteti, Podagrica uniforma, antioxidant enzymes, hydrolytic enzymes DOI: 10.7176/ALST/75-05 Publication date:June 30th 2019

Factors affecting the selection of effective cost control techniques in the UK construction industry

Purpose - This paper aims to identify and analyse the factors affecting the selection of effective cost control techniques in the UK construction industry and assess their importance. The study examines these key areas; (i) the factors that have significant impacts on cost overruns, (ii) the most effective cost control techniques, and (iii) the factors for selecting cost control techniques for a project. Design/methodology/approach - The study relies on a mixed-method research approach; a qualitative exploration of the most effective cost control techniques and the factors affecting the selection of cost control techniques, followed by a questionnaire survey and follow-up interviews. Relative Importance Index (RII) is used for ranking the factors. Research limitations/implications - Although the scope of the study was limited to the UK construction industry, the results could be interpreted for critical learning in other developed/developing countries. Findings - Budgeting technique is ranked first with-0.821RII, followed by cost forecasting-0.800RII and cashflow monitoring-00.733RII, as the most effective cost control techniques. On factors that influenced the choice of the techniques used, cost information/cost-related factors is ranked first with-0.611RII, followed by the size of the company-0.509RII and the effectiveness of the technique-0.572RII. Originality/value – Identifying and ranking the factors affecting the selection of effective cost control techniques in the UK construction industry has been the focal point of this study. The study also proposes a simple but effective model which can be used for critical learning on mitigating cost overruns and the effective use of cost control techniques in the construction industry

Skill competency development strategies by a contractor

Construction skills are one of the vital aspects of construction work which is growing in importance due to skill gaps and skill shortages during different economic cycles. The aim of this study was to investigate competence development strategies by a traditional construction company within its own pool of skill resources and among its supply chain members. The study was carried out via literature review, empirical studies involving a focus study, analysis of documentary evidence supported by unstructured interviews and a report of skill development/supply chain conference. The study demonstrates how long-term skill development can be achieved through: (a) strategic capacity planning which allows high retention, continuous training, and balanced construction demand and contractor’s supply capacity over the long term; (b) updating and upgrading the knowledge base of the supply chain through conferences and training schemes; (c) strategic investment in the workforce through training, vocational and higher degrees; and (d) acquaintance with different sources of finance. This study will assist small traditional firms in building competencies in skill development and improvement. It will assist an international audience who may face similar issue with their construction firm

Experimental analytical design of CNC machine tool SCFC based on electro-pneumatic system simulation

AbstractA Smart Clamping Force Control (SCFC) is adapted to hold sensitive workpiece using magnetic proximity switch during a machining operation on the CNC machine tool. It has been ascertained that work-holding of different workpiece materials and shapes during machining operation is one of the problems encountered during CNC milling machining operations. This work proposes a novel clamping strategy for workpieces with the aid of SCFC. The purpose of the study is to adjust the forward movement of the clamp and reduce the damage caused by the clamp on the workpiece, this depends on the material of the work-piece. The speed of the clamp is reduced using the inlet flow control throttle valve and a magnetic proximity switch (MPS). It provides careful handling of workpiece and prevent it from damage and as well optimizes the forward movement of the cylinder. The proposed strategy is based on dynamic machine loading in which the impact of applied forces were monitored to optimize the clamping control system of the machine tool. The mode of operation and performance of the SCFC were simulated in the FluidSIM® software, and the validated results was presented on Festo workstation. This work therefore further elucidate the fundamental design criterion for machine tool clamping forces and the sustainable manufacture of its components