Effect of Passive Flow-Control Devices on Turbulent Low-Speed Base Flow

Some configurations of blunt trailing-edge airfoils are known to have a lower pressure drag compared to sharp trailing-edge airfoils. However, this advantage in addition to the structural advantage of a thick trailing-edge airfoil is offset by its high base drag. At subsonic velocities, this is attributed to the low-pressure base flow dominated by a Karman vortex street. In the limiting case, the steady separated flow over a rearward-facing step is attained if the periodically shed vortices from a blunt trailing-edge are suppressed by the addition of a base splitter-plate. Experimental studies in the Old Dominion University low-speed closed-circuit wind tunnel were conducted to examine the effect of several passive flow-control devices such as Wheeler doublets and wishbone vortex generators, longitudinal surface grooves, base cavities and serrations on the characteristics of two- and three-dimensional base flows. Flow over flat-plate airfoil and rearward-facing step models was studied in the turbulent incompressible subsonic flow regime. Models with trailing-edge and step-sweep angles of 0°, 30°, and 45° with respect to the crossflow direction were considered. Constant-temperature hot-wire anemometry, infrared surface thermography, and pitot-static probes were used to conduct flow measurements. Parameters measured included vortex shedding frequency, convective heat-transfer rates, base pressure, and flow reattachment distance. Surveys of mean velocity profiles in the wake were also conducted. Results have shown that most of the flow control devices tested increased the base pressure of the 2-D and 3-D flat-plate airfoils. Use of longitudinal surface grooves resulted in shorter flow reattachment distances and higher convective heat transfer rates downstream of the 2-D rearward-facing steps

Pathogenesis of malignant pleural mesothelioma and the role of environmental and genetic factors

Malignant pleural mesothelioma (MPM) is a rare, aggressive tumor for which no effective therapy exists despite the discovery of many possible molecular and genetic targets. Many risk factors for MPM development have been recognized including environmental exposures, genetic susceptibility, viral contamination, and radiation. However, the late stage of MPM diagnosis and the long latency that exists between some exposures and diagnosis have made it difficult to comprehensively evaluate the role of risk factors and their downstream molecular effects. In this review, we discuss the current molecular and genetic contributors in MPM pathogenesis and the risk factors associated with these carcinogenic processes

THE STUDY OF THE EFFECT OF ETHICAL CLIMATE ON THE UNIVERSITY STUDENTS' EDUCATIONAL ATTITUDES IN OPERATING ROOM

ABSTRACTObjective: Health-care students should be properly trained to be able to solve the society problems in the future. One of the factors affecting theacademic progress of students is student's educational attitudes that are affected by the factors such as their learning environment's climate. Theaim of the current study is studying the ethical climate on the university students' educational attitudes in the operating room of the medical scienceuniversity in Zahedan.Methods: In this descriptive-analytical study, the students were selected by census method (62 students). To collect the data, a three-part questionnairewas used that the first part was related to the demographic features, the second part was related to the educational attitude, and the third part wasrelated to Olson's standard questionnaire. The data were analyzed in SPSS 19 by statistical tests, t-test, and variance analysis.Results: The average age of students was 21.65±1.63 and 36 participants were female and 26 participants were male. 34 participants were educatingin semester 4 and 28 participants were educating semester 8. The average score of educational attitude was 87.01±9.20 and the average score ofethical climate was 15.58±92.85, and the significant relationships were observed between the ethical climate and educational attitude (p=0.03).Conclusion: The results of this study showed that students have a positive view of their field of study and existence ethical climate and managers, andofficials should try to maintain this situation, and the relationship between the ethical climate and educational attitude was significant.Keywords: Educational attitude, Ethical climate, The university students, Operating rooms

DiFair: A Benchmark for Disentangled Assessment of Gender Knowledge and Bias

Numerous debiasing techniques have been proposed to mitigate the gender bias that is prevalent in pretrained language models. These are often evaluated on datasets that check the extent to which the model is gender-neutral in its predictions. Importantly, this evaluation protocol overlooks the possible adverse impact of bias mitigation on useful gender knowledge. To fill this gap, we propose DiFair, a manually curated dataset based on masked language modeling objectives. DiFair allows us to introduce a unified metric, gender invariance score, that not only quantifies a model's biased behavior, but also checks if useful gender knowledge is preserved. We use DiFair as a benchmark for a number of widely-used pretained language models and debiasing techniques. Experimental results corroborate previous findings on the existing gender biases, while also demonstrating that although debiasing techniques ameliorate the issue of gender bias, this improvement usually comes at the price of lowering useful gender knowledge of the model

An Analysis of Collocation on GPUs for Deep Learning Training

Deep learning training is an expensive process that extensively uses GPUs, but not all model training saturates modern powerful GPUs. Multi-Instance GPU (MIG) is a new technology introduced by NVIDIA that can partition a GPU to better-fit workloads that do not require all the memory and compute resources of a full GPU. In this paper, we examine the performance of a MIG-enabled A100 GPU under deep learning workloads containing various sizes and combinations of models. We contrast the benefits of MIG to older workload collocation methods on GPUs: na\"ively submitting multiple processes on the same GPU and utilizing Multi-Process Service (MPS). Our results demonstrate that collocating multiple model training runs may yield significant benefits. In certain cases, it can lead up to four times training throughput despite increased epoch time. On the other hand, the aggregate memory footprint and compute needs of the models trained in parallel must fit the available memory and compute resources of the GPU. MIG can be beneficial thanks to its interference-free partitioning, especially when the sizes of the models align with the MIG partitioning options. MIG's rigid partitioning, however, may create sub-optimal GPU utilization for more dynamic mixed workloads. In general, we recommend MPS as the best performing and most flexible form of collocation for model training for a single user submitting training jobs

Design of Piezoelectric Tile for Energy Harvesting: Experimental Approach

The generation of electricity by renewable energies is an important need of today's society. Piezoelectric energy harvesting is one of these useful technologies which can generate electricity by applying external force on piezoelectric material. This study illustrates more power generation from piezoelectric tile by changing the situation of piezo discs and connect to proportional electrical circuit. Two different designs of piezoelectric tile are presented by performing experimental analyses. The experimental results showed that placing piezoelectric elements in a bending position leads to higher power generation in comparison with traditional flat positioning, which was approximately 78 times far superior. It is also revealed that by design of an electrical circuit, the tile can be advantageous for lighting in crowded sidewalks with required lighting time. The results of this paper can be beneficial in the design and fabrication of these tiles for different applications