Optimization of mechanical properties of chitosan/phenol formaldehyde composite

The Frechet distribution which has a scale and shape parameters, has been found to have wide application in modelling extreme events such as radioactive emission, flood, rainfall, seismic analysis, wind speed, etc. In this research paper, the Bayesian analysis of scale parameter of Frechet distribution was considered. It is necessary to know the best combination of prior distribution and loss function for the parameter estimation. Posterior distribution was derived by uniform and Jeffrey’s prior under the square error, Precautionary, Quadratic and Weighted balance loss function. Bayes estimation and their corresponding risk was obtained by the above stated priors and loss function. Monte Carlo simulations was conducted to compare the performance of the estimators. It is evident that weighted balance loss function when used with uniform prior provides the least posterior risk.Keywords: Frechet Distribution, Non-Informative Prior, Bayesian Estimation, Loss Functions, Monte Carlo Simulation

Equilibrium, Adsorption Isotherm and Kinetic Studies on the Removal of Methylene Blue Dye from Aqueous Solution onto Senna Occidentalis Seeds Activated Carbon

This paper studied the adsorption potentials and efficiency of low cost activated carbon produced from Senna occidentalis seeds for the removal of Methylene Blue dye in aqueous solutions. Batch adsorption experiments were carried out to investigate the effects of variables such as initial dye concentration, carbon dosage, contact time, pH and temperature to the process. Similarly, adsorption isotherms consisting Langmuir, Freundlich and Temkin were employed and found Langmuir Adsorption model fitted best. However, Kinetic models consisting pseudo first-order, pseudo second-order and intra-particle diffusion were also used to investigate the kinetic nature of the process, and found that pseudo second-order model better explained the process. Keywords: Equilibrium, Adsorption Isotherm, Kinetic Studies, Activated Carbon and Methylene Blue Dye DOI: 10.7176/CMR/11-4-04 Publication date: April 30th 201

Effect of particle size on tensile properties and density of Delonix regia seed particles filled unsaturated polyester resin composites

This study was aimed at examining the effect of particle size on the tensile properties and density of Delonix regia seed particles (DSP) filled unsaturated polyester resin (UPR) composites. The composites were fabricated using a glass mould via hand mixing, and the average DSP particle sizes of 100, 200, 300, 400, and 500 μm were used at 12 % filler loading. The effect of particle size on the tensile properties and density of DSP-filled unsaturated polyester resin was investigated. The results showed a decrease in tensile strength, tensile modulus, elongation at break, and density as the filler particle size increased. The smallest particle size (100 μm) has the highest values of tensile strength, tensile modulus, elongation at break (%) and density with the corresponding values of 35.43 MPa, 0.47 GPa, 7.09% and 1.22 g/cm3 and the largest particle size (500 μm) with values of 15.25 MPa, 0.28 GPa, 5.17% and 1.12 g/cm3 respectively

Kinetics and mechanism of the redox reaction of orange II with thiosulphate ion in aqueous acid

The kinetics of the redox reaction of orange II (OR-) with thiosulphate ion has been studied spectrophotometrically at constant ionic strength, I = 0.50 mol dm-3 (NaCl), [H+] = 5.0 X 10-2 mol dm-3 (HCl) and T = 26 ± 1°C. The redox reaction displayed a stoichiometry of 1:4 and rate equation for the reaction is-d[OR-]/dt = (a + b[H+])[OR-][S2O32-]The rate of the reaction increases with increase in acid concentration and in the ionic strength of reaction medium. The reaction shows a first order dependence on [oxidant] and [reductant]. Added cations and anions inhibited the rate of the reaction. Michaelis – Menten’s plot of 1/k1 versus 1/ S2O32- and spectrophotometric test suggest absence of an intermediate in the rate determining step. Free radical test did not yield gel formation. Based on the results obtained, this reaction is probably operating through the outersphere mechanism

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Isolation, Molecular Detection and Antimicrobial Susceptibility Profile of Escherichia coli O157:H7 in Household - reared Small Ruminants in Zaria Metropolis, Kaduna State, Nigeria

Escherichia coli O157:H7 is a zoonotic enteric pathogen of public health significance worldwide. A cross-sectional study was carried out during which 384 faecal samples of household-reared small ruminants and water used in the various houses where the animals are reared were collected. The samples were enriched on tryptone soya broth and cultured on EMB and CT-SMAC to isolate E. coli and E. coli O157:H7 respectively; subjected to conventional biochemical tests and E. coli O157:H7 was confirmed using Wellcolex latex agglutination test kit. E. coli O157:H7 isolates were subjected to antimicrobial susceptibility test and multiplex PCR was carried out to detect the presence of virulence genes stx1, stx2, eaeA and hlyA. The results of the isolation showed isolation rate of E. coli O157:H7 of 4.69% (9/192), 0.52% (1/192) which were obtained from faeces and water samples respectively. The results of the characterisation showed that one of the E. coli O157:H7 isolated harboured the eaeA and hlyA genes but was negative for stx1 and stx2 genes. The highest number of isolates showed resistance to erythromycin (90.9%) while the least was to gentamicin (6.3%). About 97.7% (43/44) of the isolates had multiple antibiotic resistance index greater than 0.2. In conclusion, household-reared small ruminants in the study area were found to be reservoirs of E. coli O157:H7 and humans living within these households are at risk of infection. The multiple antibiotic resistance recorded in this study suggests wide spread use of antimicrobial drugs in the study area. Keywords: Escherichia coli O157:H7, Household-reared small ruminants, Latex agglutination, Multiplex PCR, Antimicrobial sensitivit

The ASOS Surgical Risk Calculator: development and validation of a tool for identifying African surgical patients at risk of severe postoperative complications

Background: The African Surgical Outcomes Study (ASOS) showed that surgical patients in Africa have a mortality twice the global average. Existing risk assessment tools are not valid for use in this population because the pattern of risk for poor outcomes differs from high-income countries. The objective of this study was to derive and validate a simple, preoperative risk stratification tool to identify African surgical patients at risk for in-hospital postoperative mortality and severe complications. Methods: ASOS was a 7-day prospective cohort study of adult patients undergoing surgery in Africa. The ASOS Surgical Risk Calculator was constructed with a multivariable logistic regression model for the outcome of in-hospital mortality and severe postoperative complications. The following preoperative risk factors were entered into the model; age, sex, smoking status, ASA physical status, preoperative chronic comorbid conditions, indication for surgery, urgency, severity, and type of surgery. Results: The model was derived from 8799 patients from 168 African hospitals. The composite outcome of severe postoperative complications and death occurred in 423/8799 (4.8%) patients. The ASOS Surgical Risk Calculator includes the following risk factors: age, ASA physical status, indication for surgery, urgency, severity, and type of surgery. The model showed good discrimination with an area under the receiver operating characteristic curve of 0.805 and good calibration with c-statistic corrected for optimism of 0.784. Conclusions: This simple preoperative risk calculator could be used to identify high-risk surgical patients in African hospitals and facilitate increased postoperative surveillance. © 2018 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.Medical Research Council of South Africa gran