Simulated Design of a Flow Control Valve forStroke Speed Adjustment of Hydraulic Power of Robotic Lifting Device

A novel method of design for a hydraulic robotic lifting equipment (HRLE) was modelled, commonly used by marinas and Automobile industries. Lifting appliances have different working principles because of their individual characteristic behaviours. This work analysis a characteristic curve made from values obtained from various adjustments of the stroke working speed of the hydraulic lift system and the time used. A hydraulic lift of an experimental setup was developed for different adjustable heights and speeds and simulated to get the actual optimum value of operation under different loading conditions. The motion was free of inconsistent movement and a steady speed was attained after a 0.6s maximum timelimit. A flow control valve and a pressure relief valve were used to adjust the speed without any extreme irregular high pressure. A demonstration for possibilities and applicability of HRLE is presented whichis applicable both in industries and institutions for learning

The Effects of Heat Generation on Cutting Tool and Machined Workpiece

Metal cutting processes usually cause heat generation at the cutting zone (around the workpiece-tool intersection). The heat generated during these processes may cause different effects on both the workpiece and tool, this in turn may affect the finished product and the general performance of the machined piece. In this study, a review was done on various types of machining conditions available, effects of heat generated on the workpiece and tool, and the approaches adopted to reduce this heat at cutting zones. This study also focuses on the simulation of percentage ratio of heat removal. To handle the simulation, various approaches of heat removal methods were used to get the percentage ratio using the ansys version 19.1 software. It was discovered that heat generation causes two major types of wear on the tool, crater and flank wear, resulting in the reduction of cutting tool life as well as dimensional inaccuracy, surface damage and severe corrosion cases on the workpiece. Various heat reduction methods and coolant application types were as well studied and their merits and demerits were discussed

Potential health and economic impacts of dexamethasone treatment for patients with COVID-19

Acknowledgements We thank all members of the COVID-19 International Modelling Consortium and their collaborative partners. This work was supported by the COVID-19 Research Response Fund, managed by the Medical Sciences Division, University of Oxford. L.J.W. is supported by the Li Ka Shing Foundation. R.A. acknowledges funding from the Bill and Melinda Gates Foundation (OPP1193472).Peer reviewedPublisher PD

Plant Layout under Discounted Sequential Machinery Investment using Dynamic Programming Approach

Dynamic programming is employed in this study to develop a model that helps entrepreneurs to populate pre-planned plant layout using discounted sequential machinery investment method. The approach enables the use of little initial capital to sequentially invest in the most important machinery/machineries and factory and office space(s) as well as to provide sufficient working capital required by the industry to keep the plant working optimally per period. In addition, it takes into consideration the time value of money that may arise from inflation on the economy during the sequential investment period using discounting method. Using the developed model and a set of decision rules that was setup, total earnings obtained from previous periods are subsequently re-invested each period, while ensuring adequate working capital, until all the planned machines and factory and office buildings have been fully put in place. The model developed was implemented through a software named DYNAPLANT2015 which was developed using C# programming language to facilitate the solution procedure. An appropriate case study was used to evaluate the model and observe possible difference between the undiscounted and discounted sequential machinery investmen

The impact of a universal late third-trimester scan for fetal growth restriction on perinatal outcomes in term singleton births: a prospective cohort study

Objective:&nbsp;To investigate perinatal mortality, morbidity and obstetric intervention following the introduction of a universal late third-trimester ultrasound scan for growth restriction. Design:&nbsp;Prospective cohort study Setting:&nbsp;Oxfordshire (OUH), UK Population:&nbsp;Women with a non-anomalous singleton pregnancy undergoing pregnancy care and term delivery at OUH with an estimated date of birth between 01/Jan/2014 and 30/Sept/2019. Methods:&nbsp;Universal ultrasound for fetal growth restriction between 35+0&nbsp;and 36+6&nbsp;weeks was introduced in 2016. The outcomes of the next 18631 eligible term pregnancies were compared, adjusting for covariates and time, with the previous 18636 who had clinically-indicated ultrasounds only. &lsquo;Screen positives&rsquo; for growth restriction were managed according to a pre-determined protocol which included non-intervention for some SGA babies. Main Outcome Measures:&nbsp;Extended perinatal mortality, a composite of mortality or encephalopathy Grade II-III, and expedited birth. Other outcomes included composite adverse outcomes used elsewhere, detection of low birthweight and birth from 37+0&nbsp;to 38+6&nbsp;weeks. Results:&nbsp;Extended perinatal deaths decreased 27% and severe morbidity decreased 33% but neither change was statistically significant (aOR 0.53; 00.18-1.56 and aOR 0.71; 0.31-1.63). Expedited births changed from 35.2% to 37.7% (aOR: 0.99 (0.92 &ndash; 1.06). Birthweight (&lt;10th&nbsp;centile) detection using fetal biometry alone was 31.4% and rose to 40.5% if all abnormal scan parameters were used. Conclusion:&nbsp;Improvements in mortality and severe morbidity subsequent to introducing a universal ultrasound for growth restriction are encouraging but remain unclear. Little change in intervention is possible. The antenatal detection of low birthweight remains poor but improves where markers of growth restriction are used.</p

Curing, thermal resistance and bending behavior of laterised concrete containing ceramic wastes

Recent years have witnessed an increase in volume of construction and demolition wastes generated in some developed and developing countries, which mostly constitute environmental issues. Therefore, it is important to explore the potential of such waste materials, or when used with locally available materials for concrete production. Thus, this research effort aims at determining the effects of curing methods (polythene wrapping and water immersion), and exposure to high temperature, on strength characteristics of laterised concrete samples made with ceramic floor tiles wastes as aggregates. The study also explored the bending behavior of steel reinforced beam mixes comprising ceramics and laterite. From the obtained results, samples made with ceramic and laterite developed higher strengths when cured with polythene covering than the water cured samples. However, the reference concrete samples developed better strength in normal curing condition (immersion in water). In terms of thermal resistance, the laterised samples had better resistance at elevated temperatures than the reference concrete. Lastly, for the tested beams, the maximum mid span bending strength decreased with increasing laterite content. Overall, it can be considered that ceramic floor tiles wastes with minimal laterite content can be used for concrete production, and by so doing, the negative impact of these wastes on the environment can be controlled

Development of OEE Error-Proof (OEE-EP) Model for Production Process Improvement

The global demand for effective utilization of both humans and machinery is increasing due to wastage incurred during product manufacturing. Excessive waste generation has made entrepreneurs find it difficult to breakeven. The development of dynamic error-proof Overall Equipment Effectiveness (OEE) model for optimizing a complex production process is targeted at minimizing/eradicating operational wastes/losses. In this study, the error-proof sigma metric was integrated into the extended traditional OEE factors (availability, performance, quality) to include losses due to waste and man-machine relationships. Error-proof sigma statistics enabled continuous corrective measures on unsatisfactory or low-level OEE resulted from process output variations (quantity delivered or expected), which were mapped into sigma statistical standards (one- to six-sigma).  Application of the model in a processing company showed that errors of the process were reduced by 78% and 42% respectively for traditional OEE and the new Error-Proof OEE (OEE-EP).  The results revealed that the OEE-EP model is better than the other existing schemes in terms of losses elimination in the production process

Comparing observed occurrence of mistreatment during childbirth with women's self-report: a validation study in Ghana, Guinea and Nigeria.

BackgroundThere has been substantial progress in developing approaches to measure mistreatment of women during childbirth. However, less is known about the differences in measurement approaches. In this study, we compare measures of mistreatment obtained from the same women using labour observations and community-based surveys in Ghana, Guinea and Nigeria.MethodsExperiences of mistreatment during childbirth are person-centred quality measures. As such, we assessed individual-level and population-level accuracy of labour observation relative to women's self-report for different types of mistreatment. We calculated sensitivity, specificity, percent agreement and population-level inflation factor (IF), assessing prevalence of mistreatment in labour observation divided by 'true' prevalence in women's self-report. We report the IF degree of bias as: low (0.75Results1536 women across Ghana (n=779), Guinea (n=425) and Nigeria (n=332) were included. Most mistreatment items demonstrated better specificity than sensitivity: observation of any physical abuse (44% sensitive, 89% specific), any verbal abuse (61% sensitive, 73% specific) and presence of a labour companion (19% sensitive, 93% specific). Items for stigma (IF 0.16), pain relief requested (IF 0.38), companion present (IF 0.32) and lack of easy access to fluids (IF 0.46) showed high risk of bias, meaning labour observations would substantially underestimate true prevalence. Other items showed low or moderate bias.ConclusionUsing self-report as the reference standard, labour observations demonstrated moderate-to-high specificity (accurately identifying lack of mistreatment) but low-to-moderate sensitivity (accurately identifying presence of mistreatment) among women. For overall prevalence, either women's self-report or observations can be used with low-moderate bias for most mistreatment items. However, given the dynamicity, complexity, and limitations in 'objectivity', some experiences of mistreatment (stigma, pain relief, labour companionship, easy access to fluids) require measurement via women's self-report. More work is needed to understand how subjectivity influences how well a measure represents individual's experiences