Free convective flow of heat generating fluid through a porous vertical channel with velocity slip and temperature jump

AbstractThis paper investigates the unsteady free convective flow of heat generating/absorbing fluid through a porous vertical channel with velocity slip and temperature jump. Exact solution of the oscillatory flow problem is obtained in the slip flow regime through a microchannel. The effects of various flow parameters on the temperature and velocity profiles together with the influence of the velocity slip and temperature jump on the rate of heat transfer and the skin friction are presented and discussed

Conflict management in tertiary institutions: A study of selected universities in south-western Nigeria

Background: Conflict constitutes a major significant factor in human interaction because of the interdependent relationship of individuals. However, its effective management and strategies are imperative for growth and development in an organisation or a society. Aim: This study examines conflict management in Nigerian tertiary institutions to examine the extent to which conflict management engendered stakeholder participation in the two institutions since their establishment and to investigate whether the performance of a conflict management board in two institutions has improved since their establishment. Setting: Nigerian tertiary institutions – with specific reference to Lagos State University, Ojo Lagos (LASU) and Adekunle Ajasin University Akungba-Akoko, Ondo state (AAUA). Methods: The study used primary and secondary sources, such as structured questionnaires, interviews and published journals, textbooks, newspapers, magazines and Internet. The sample size consisted of 500 respondents (280 from LASU and 220 from AAUA, respectively). Percentage method and Chi-square non-parametric technique were used to analyse the data. Results: The study findings revealed that conflict management has engendered stakeholder participation in decision-making and conflict resolution in the selected universities. Also, the performance of the conflict management board in LASU and AAUA has recorded significant progress in terms of managing crisis and peace building. Conclusion: The study concludes that conflict in the spate of tertiary institutions and it hinders the development of the educational system. Hence, it is impossible to attain a conducive environment in the higher institutions characterised by conflict. The study advocates for strong effective mechanisms on conflict management that will pave the way for stakeholders’ participation in decision-making of institutions

Impact of Hall Current on the Entropy Generation of Radiative MHD Mixed Convection Casson Fluid

One of the fundamental problems in engineering processes is the efficient utilization of energy during convection in fluid flow. Studies show that entropy generation exists for all fluid transfer processes and entropy generation destroys useful energy. Furthermore, it has been discovered that some pertinent flow parameters might be chosen in order to minimize entropy generation inside the system. In view of this, the fully developed electrically conducting free convection Casson fluid flow formed by two infinite vertical parallel plates with thermal radiation, Hall current and rotation effects is investigated. The governing equations have been obtained and transformed by suitable transformation variables. Semi-analytical solutions via differential transform technique are obtained using relevant boundary conditions. The results are utilized to calculate fluid irreversibility and Bejan number. The impacts of Hall parameter, rotation parameter, thermal radiation, Casson parameter, Hartman number, Schmidt number and chemical reaction together with skin friction, Nusselt number and Sherwood number are discussed and presented via plots and tables. Generally, entropy generation is discouraged at the upper walls of the channel with higher values of Casson parameter, Schimdt number and chemical reaction parameter while Hall current parameter boost entropy generation in the entire flow channel. Furthermore, Heat transfer irreversibility dominates entropy generation due to a rise in the values of chemical reaction parameter and Schmidt number

Entropy Generation of Unsteady MHD Couette Flow through Vertical Microchannel with Hall and Ion Slip Effects

In this work, the entropy generation of unsteady hydromagnetic Couette flow through vertical microchannel has been considered, the effects of Hall current and Ion-slip are also examined. One of the plates moves with uniform velocity in the direction of the fluid flow while the other plate is stationary. The partial differential equations governing the flow are obtained and transformed to ordinary differential equations. The obtained solutions for the velocity and energy equations via differential transform technique are used to calculate the entropy generation and Bejan number. The results are presented through plots and discussed. It is noticed that primary velocity decreases with increase in Hall current, ionslip and magnetic field parameters whereas it increases as rarefaction parameter, wall-ambient temperature difference ratio, Brinkman number and Grashof number increase in values. Also secondary velocity receives a boost with increase in Hall current, Ion-slip, rarefaction parameters, wall-ambient temperature difference ratio, Brinkman and Grashof numbers. Furthermore, entropy generation is minimised as Hall current, Ion-slip and rarefaction parameters increase

A robust energy policy review of selected African countries: An impetus for energy sustainability in Nigeria

Power rationing has become the bane of the Nigerian power sector, plunging the nation into prolonged periods of darkness and costing about 2.5 percent of her GDP annually. Although, installed generating capacity is almost 13 GW, the situation worsened by an overdependence on thermal and hydro generation, high losses, and a poor tariff structure. In the face of these challenges, Nigeria seeks to achieve universal access by 2030 with sustainable power having a share of 30 per cent in her energy mix. Despite the existence of frameworks supporting this target, Nigeria's policies are still weak; indicated by her low Regulatory Indicator for Sustainable Energy (RISE) score of 30. To reach universal access by 2030 and fulfil SDG 7; Nigeria needs the right mix of policies. This study aims to review, draw lessons from the successful and unsuccessful implementation of similar policies in five countries and give recommendations

Control of wax moth, Galleria mellonella L. (Lepidoptera: Pyralidae) in post harvest honey comb

An experiment was carried out in the laboratory to control the infestation of larger wax moth, Galleria mellonella, after honey extraction. Different quantities of salt in water and hermetic storage were used as methods of controlling the larvae. A treatment containing Aluminium phosphide tablet was incorporated as a chemical method of control and the treated honeycomb samples were stored for two month. Of all the treatments used, the hermetic storage and Aluminium phosphide had the best result in that the comb retained their freshness post two months storage. The number of emerged moth in opened untreated control (61.00) was higher than other treatments but significantly higher than the number of emerged moth observed in salt- treated comb in opened containers. Wax and slum gum weight were not significantly affected by the treatments. Hermetic storage is therefore recommended as a better method of controlling wax moth in honeycomb after the extraction of honey than Aluminium phosphide, due to the possibility of residue of Aluminium phosphide in the treated honeycomb. Key words: Honeycomb, Galleria mellonella, salt, hermetic storage, Aluminium phosphide, bee wax, wax moth contro

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112

Global economic burden of unmet surgical need for appendicitis

Background: There is a substantial gap in provision of adequate surgical care in many low-and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods: Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results: Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US $92 492 million using approach 1 and$73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was $95 004 million using approach 1 and$75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion: For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially