Development of interactive and remote learning instruments for engineering education

Many educators have argued for and against the use of remote aids in support of student learning. Some proponents argue that only remote laboratories should be used whereas others argue for the requirement for hands on experience with associated tactical, visual and auditory learning experiences. In this paper we present the methodology for developing a middle ground Virtual Instruments that can be used as a complement learning aid to the hands on laboratory and also if necessary, with added features, can be used as a remote version of the laboratory

Computational control of laser systems for micro-machining

Depending on the size and geometry, laser-microfabricated structures in transparent materials have applications in telecommunications, microfluidics, micro-sensors, data storage, glass cutting and decorative marking applications. The relations of Nd:YV04 and C02 laser system parameter settings to the dimensions and morphology of microfabricated structures were examined in this work. Laser system parameters investigated included power, P, pulse repetition frequency, PRF, number of pulses, N, and scanning speed, U. Output dimensions measured included equivalent voxel diameter as well as microchannel width, depth and surface roughness. A 3D microfabrication system was developed using the Nd:YV04 laser (2.5 W, 1.064 pm, 80 ns) to fabricate microstructures inside polycarbonate samples. Microstructure voxels ranged from 48 to 181 pm in diameter. Tight focusing was also achieved with this system using a microscope objective lens to produce smaller voxels ranging from 5 to 10 pm in soda-lime glass, fused silica and sapphire samples. The C02 laser (1.5 kW, 10.6 pm, minimum pulse width of 26 ps) was used to fabricate microchannels in soda-lime glass samples. The cross-sectional shapes of the microchannels varied between v-shape grooves, u-shaped groves and superficial ablated regions. Microchannels dimensions also varied with widths ranging from 81 to 365 pm, depths ranging from 3 to 379 pm and surface roughness between 2 to 13 pm being produced depending on the process settings. The microchannel dimensions were studied in terms of the laser processing parameters using the response surface methodology (RSM) with the design of experiments technique (DOE). The collected results were used to study the effect of the process parameters on the volumetric and mass ablation rates. Moreover, a thermal mathematical model of the process was also developed in order to aid understanding of the process and to allow channel topology prediction a priory to actual fabrication

3D transient thermal modelling of laser microchannel fabrication in lime-soda glass

Laser-fabricated microchannels in glass offer a wide range of bioengineering and telecommunication applications. A 1.5 kW CO2 laser with 10.6 μm wavelength was used in this study to fabricate micorchannels on the surface of soda-lime glass sheets. A thermal model of the process was developed based on transient heat conduction due to a pulsed heat input. The resulting equation predicted the temperature distribution in the regions surrounding the laser focus. Temperature – time curves were drawn from those equations, which were useful in estimating the thermal history in the processed samples. The temperature distribution was also used to predict the channel geometry (based on the vaporisation temperature of glass). Most of the laser power used was consumed in bringing the glass to the vaporisation temperature. The model was able to predict the channel width, depth and surface roughness. These laser-fabricated channel characteristics were measured and compared to the results obtained from the thermal model. The laser power, frequency, pulse width and translation speed were the control parameters in both studies; hence a direct comparison was established between the model and the experimental results

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

The Cholecystectomy As A Day Case (CAAD) Score: A Validated Score of Preoperative Predictors of Successful Day-Case Cholecystectomy Using the CholeS Data Set

Background Day-case surgery is associated with significant patient and cost benefits. However, only 43% of cholecystectomy patients are discharged home the same day. One hypothesis is day-case cholecystectomy rates, defined as patients discharged the same day as their operation, may be improved by better assessment of patients using standard preoperative variables. Methods Data were extracted from a prospectively collected data set of cholecystectomy patients from 166 UK and Irish hospitals (CholeS). Cholecystectomies performed as elective procedures were divided into main (75%) and validation (25%) data sets. Preoperative predictors were identified, and a risk score of failed day case was devised using multivariate logistic regression. Receiver operating curve analysis was used to validate the score in the validation data set. Results Of the 7426 elective cholecystectomies performed, 49% of these were discharged home the same day. Same-day discharge following cholecystectomy was less likely with older patients (OR 0.18, 95% CI 0.15–0.23), higher ASA scores (OR 0.19, 95% CI 0.15–0.23), complicated cholelithiasis (OR 0.38, 95% CI 0.31 to 0.48), male gender (OR 0.66, 95% CI 0.58–0.74), previous acute gallstone-related admissions (OR 0.54, 95% CI 0.48–0.60) and preoperative endoscopic intervention (OR 0.40, 95% CI 0.34–0.47). The CAAD score was developed using these variables. When applied to the validation subgroup, a CAAD score of ≤5 was associated with 80.8% successful day-case cholecystectomy compared with 19.2% associated with a CAAD score >5 (p < 0.001). Conclusions The CAAD score which utilises data readily available from clinic letters and electronic sources can predict same-day discharges following cholecystectomy

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

Self-centric cyclic resistance of reinforced concrete shear wall with Shape Memory Alloy: Numerical and experimental large-scale model

Over several decades, numerous researches have been routed to forge ahead in enhancing the building performance against dynamic loads. Nowadays, smart materials such as Shape Memory Alloy (SMA) have found profound impact in many applications of civil engineering. Nickel titanium alloy (NiTi) is one of the most famous among types of SMA. The current paper studies the behavior of shear wall, representing one of the most efficient lateral bracing element, structured by NiTi subjected to cyclic loading. Due to the unique characteristics of NiTi particularly in capacity to restore its original shape after unloading, the improvement in shear wall displacement recovery, wall ductility, hysteric behavior and inter-story drift ratio is presented. For this purpose, experiment study on large scale shear walls with aspect ratio 1.9 is conducted to investigate the effect of the intensity of NiTi on cyclic response. Two ordinary walls, as reference structures, and two hybrid walls are set up in order to perform the study. In addition, the validation of numerical simulation is examined by comparing its results with that obtained by the experiments and a pretty much in agreement is found. Hence, three-dimensional modeling by mean of ANSYS19 is extended to study the effect of NiTi length throughout the wall height on the shear wall response. The results showed that the existing of NiTi controls the cracks propagation and confines the majority in the lower third of the wall. Furthermore, for NiTi-wall, the study showed remarkable enhancement in recover capacity by 77 % and significantly increase in drift capacity ratio by 16.5 % relies on the NiTi ratio. Besides, some significant observations like the profile of wall curvature and energy dissipation are analyzed in this paper