DEVELOPMENT OF AN IMPROVED PRESSURE VARYING HYDRAULICALLY OPERATED AGRICULTURAL WASTE BRIQUETTING MACHINE

In several developing countries, briquettes from agricultural residues contribute significantly to the energy mix especially for small scale and household requirements. Most times, these briquettes are produced from a manually operated briquetting machine where the pressure at which the agricultural waste is compressed cannot be ascertained. Therefore, this work deals with the design and fabrication of pressure varying hydraulically operated briquetting machine. This machine can produce sixteen (16) briquettes at a time. The machine was developed in other to reduce the stress of producing the briquette and to establish the optimum pressure at which the agricultural waste is compressed. The varying pressure at which the briquette is compressed was used to establish the effect of pressure on the calorific value of the briquette. The agricultural waste that was used for the briquette includes palm kernel shell, rice bran, and sawdust with cassava starch as the binder. Each agricultural waste particle was load in the machine mold at different times at varying pressure of 30, 70, and 100kg/cm2. The result shows that the briquette of sawdust has the highest heating value of 17.585 at 70kg/cm2 pressure while the highest value was recorded for rice bran as 13.722 at 100kg/cm2 and   18.342 MJ/kg at 100kg/cm2 pressure for palm kernel shell

DEVELOPMENT OF AN EXPERT SYSTEM FOR MATERIAL SELECTION OF MACHINE PARTS

Engineering Material selection is a very difficult task because of unlimited available materials. This research was carried out to develop a user-friendly interface that would allow an individual to filter through a large number of materials in order to find the most suitable material options for the production of some selected machine parts. Material selection mathematical models, for twenty-five common machine parts, were developed using the Ashby model format. The software tool used in the development of the expert system is PHPMyAdmin. This was written in Hypertext pre-processor (PHP) language designed to handle the administration of MY Structure Query Language (MySQL) server over the World Wide Web. The system was implemented using the Expert system to predict the material for machine parts of the previously fabricated project. The result of these tests shows that for a developed soya beans milk extraction machine, the software suggested low carbon steel for the shaft in place of mild steel used for the fabrication. Comparing the software predictions for shaft materials with standard materials (in textbooks) used `for manufacturing these parts shows greater conformity. The software is highly recommended for manufacturing industries to improve their material choice for mass production

Development of ferro-alloy hardfacing for high abrasion and low impact wear applications

Extension of service lives of critical machine components subjected to wear is possible through application of hardfacing alloys. In this work, two hardfacing alloys were produced based on the mass ratios of 2: 1: 1 and 7: 1.5: 1.5 for Fe: Mn: Cr by sand and open permanent mold casting processes, respectively. XRD analysis of both samples showed the prominent presence of (Mn, Cr)23C6, (Fe, Mn, Cr)7C3, Cr3C2, Fe3C2 and Fe4C carbides. Hӓgg carbide was prevalent in the SEM microstructural analysis of the sand cast sample, while cementite dominated the permanent mold cast sample. The average hardness values, impact energies absorbed and wear volumes of the samples produced with their respective charge mass ratios are 567 HV, 30 J and 0.131 cm3 for 2: 1: 1 ratio and 592 HV, 29.5 J and 0.085 cm3 for the 7: 1.5: 1.5 ratio. For service life applications as jaws, rolls, mantles, and concaves in crushers, the latter was recommended for manual metal arc welding to low carbon steel substrate because of its higher hardness, lower wear volume and cheaper alloy cost

The Origins and Future of Sentinel: An Early-Warning System for Pandemic Preemption and Response

While investigating a signal of adaptive evolution in humans at the gene LARGE, we encountered an intriguing finding by Dr. Stefan Kunz that the gene plays a critical role in Lassa virus binding and entry. This led us to pursue field work to test our hypothesis that natural selection acting on LARGE—detected in the Yoruba population of Nigeria—conferred resistance to Lassa Fever in some West African populations. As we delved further, we conjectured that the “emerging” nature of recently discovered diseases like Lassa fever is related to a newfound capacity for detection, rather than a novel viral presence, and that humans have in fact been exposed to the viruses that cause such diseases for much longer than previously suspected. Dr. Stefan Kunz’s critical efforts not only laid the groundwork for this discovery, but also inspired and catalyzed a series of events that birthed Sentinel, an ambitious and large-scale pandemic prevention effort in West Africa. Sentinel aims to detect and characterize deadly pathogens before they spread across the globe, through implementation of its three fundamental pillars: Detect, Connect, and Empower. More specifically, Sentinel is designed to detect known and novel infections rapidly, connect and share information in real time to identify emerging threats, and empower the public health community to improve pandemic preparedness and response anywhere in the world. We are proud to dedicate this work to Stefan Kunz, and eagerly invite new collaborators, experts, and others to join us in our efforts

Adaptation of the Wound Healing Questionnaire universal-reporter outcome measure for use in global surgery trials (TALON-1 study): mixed-methods study and Rasch analysis

BackgroundThe Bluebelle Wound Healing Questionnaire (WHQ) is a universal-reporter outcome measure developed in the UK for remote detection of surgical-site infection after abdominal surgery. This study aimed to explore cross-cultural equivalence, acceptability, and content validity of the WHQ for use across low- and middle-income countries, and to make recommendations for its adaptation.MethodsThis was a mixed-methods study within a trial (SWAT) embedded in an international randomized trial, conducted according to best practice guidelines, and co-produced with community and patient partners (TALON-1). Structured interviews and focus groups were used to gather data regarding cross-cultural, cross-contextual equivalence of the individual items and scale, and conduct a translatability assessment. Translation was completed into five languages in accordance with Mapi recommendations. Next, data from a prospective cohort (SWAT) were interpreted using Rasch analysis to explore scaling and measurement properties of the WHQ. Finally, qualitative and quantitative data were triangulated using a modified, exploratory, instrumental design model.ResultsIn the qualitative phase, 10 structured interviews and six focus groups took place with a total of 47 investigators across six countries. Themes related to comprehension, response mapping, retrieval, and judgement were identified with rich cross-cultural insights. In the quantitative phase, an exploratory Rasch model was fitted to data from 537 patients (369 excluding extremes). Owing to the number of extreme (floor) values, the overall level of power was low. The single WHQ scale satisfied tests of unidimensionality, indicating validity of the ordinal total WHQ score. There was significant overall model misfit of five items (5, 9, 14, 15, 16) and local dependency in 11 item pairs. The person separation index was estimated as 0.48 suggesting weak discrimination between classes, whereas Cronbach's α was high at 0.86. Triangulation of qualitative data with the Rasch analysis supported recommendations for cross-cultural adaptation of the WHQ items 1 (redness), 3 (clear fluid), 7 (deep wound opening), 10 (pain), 11 (fever), 15 (antibiotics), 16 (debridement), 18 (drainage), and 19 (reoperation). Changes to three item response categories (1, not at all; 2, a little; 3, a lot) were adopted for symptom items 1 to 10, and two categories (0, no; 1, yes) for item 11 (fever).ConclusionThis study made recommendations for cross-cultural adaptation of the WHQ for use in global surgical research and practice, using co-produced mixed-methods data from three continents. Translations are now available for implementation into remote wound assessment pathways