2,147 research outputs found

    Multi-response optimization of face milling performance considering tool path strategies in machining of Al-2024

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    It is hypothesized that the orientation of tool maneuvering in the milling process defines the quality of machining. In that respect, here, the influence of different path strategies of the tool in face milling is investigated, and subsequently, the best strategy is identified following systematic optimization. The surface roughness, material removal rate and cutting time are considered as key responses, whereas the cutting speed, feed rate and depth of cut were considered as inputs (quantitative factors) beside the tool path strategy (qualitative factor) for the material Al 2024 with a torus end mill. The experimental plan, i.e., 27 runs were determined by using the Taguchi design approach. In addition, the analysis of variance is conducted to statistically identify the effects of parameters. The optimal values of process parameters have been evaluated based on Taguchi-grey relational analysis, and the reliability of this analysis has been verified with the confirmation test. It was found that the tool path strategy has a significant influence on the end outcomes of face milling. As such, the surface topography respective to different cutter path strategies and the optimal cutting strategy is discussed in detail

    Exotic fish and decreasing habitats vis-Ă -vis conservation of freshwater fish biodiversity of Bangladesh

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    Multiple stressors including biological invasion have long been recognised in conservation of freshwater fish biodiversity. Works in this line have, however, been still scanty in Asia and South America – the continents known for rich biodiversity. In this study, the first of its type in Bangladesh, impacts of exotic fish and declining habitats on native fishes have been investigated. Regression and correlation analyses of 16 years production data of ponds, practically the only habitat where exotic fish are cultured commonly with indigenous ones, reveals that a maximum of 25% of the abundance decrease of native fish could be due to the effects of five commonly cultured exotic fish. Rest of the decline might largely be due to shrinkage, degradation, and destruction of habitats. Inland habitats other than ponds shrink, commonly, by about 80 % during the dry season, and most rivers are heavily polluted except for the brief mid rainy season. Decline in native fish populations may result in reduced genetic diversity. Another potential danger is the probable genetic introgression from the less fit hatchery-originated fish with the wild ones. The study concludes that the native freshwater fishes are endangered by declining habitats, exotic fishes, genetic consequences of hatchery supplementatio

    Testimonial Therapy: Impact on social participation and emotional wellbeing among Indian survivors of torture and organized violence

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    Introduction: Traumatizing events, such as torture, cause considerable impairments in psycho-social functioning. In developing countries, where torture is often perpetrated, few resources exist for the provision of therapeutic or rehabilitating interventions. The current study investigated the effectiveness of Testimonial Therapy (TT) as a brief psycho-social intervention to ameliorate the distress of Indian survivors of torture and related violence. Method: Three outcome measures (the WHO-5 Well-Being Scale, Social Participation-Scale and Pain and Anger Analogue) were compared before and after receiving TT, and semi-structured interviews were conducted with survivors who had previously received TT. Findings: Participants showed significant improvements in emotional well-being, social participation, and self-perceived pain and anger. Furthermore, three qualitative interviewswith survivors indicated that TT had a positive impact at the community level. Discussion: Although the study was conducted without a control group for comparison, TT appeared to be an effective method for improving well-being and ameliorating distress among survivors of torture. Furthermore, TT can potentially promote community empowerment. However, more research on this aspect is needed

    Multi-objective optimization of energy consumption and surface quality in nanofluid SQCL assisted face milling

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    Considering the significance of improving the energy efficiency, surface quality and material removal quantity of machining processes, the present study is conducted in the form of an experimental investigation and a multi-objective optimization. The experiments were conducted by face milling AISI 1045 steel on a Computer Numerical Controlled (CNC) milling machine using a carbide cutting tool. The Cu-nano-fluid, dispersed in distilled water, was impinged in small quantity cooling lubrication (SQCL) spray applied to the cutting zone. The data of surface roughness and active cutting energy were measured while the material removal rate was calculated. A multi-objective optimization was performed by the integration of the Taguchi method, Grey Relational Analysis (GRA), and the Non-Dominated Sorting Genetic Algorithm (NSGA-II). The optimum results calculated were a cutting speed of 1200 rev/min, a feed rate of 320 mm/min, a depth of cut of 0.5 mm, and a width of cut of 15 mm. It was also endowed with a 20.7% reduction in energy consumption. Furthermore, the use of SQCL promoted sustainable manufacturing. The novelty of the work is in reducing energy consumption under nano fluid assisted machining while paying adequate attention to material removal quantity and the product’s surface quality

    Investigations of machining characteristics in upgraded MQL assisted turning of pure titanium alloy using evolutionary algorithms

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    Environmental protection is the major concern of any form of manufacturing industry today. As focus has shifted towards sustainable cooling strategies, minimum quantity lubrication (MQL) has proven its usefulness. The current survey intends to make the MQL strategy more effective while improving its performance. A Ranque–Hilsch vortex tube (RHVT) was implemented into the MQL process in order to enhance the performance of the manufacturing process. The RHVT is a device that allows for separating the hot and cold air within the compressed air flows that come tangentially into the vortex chamber through the inlet nozzles. Turning tests with a unique combination of cooling technique were performed on titanium (Grade 2), where the effectiveness of the RHVT was evaluated. The surface quality measurements, forces values, and tool wear were carefully investigated. A combination of analysis of variance (ANOVA) and evolutionary techniques (particle swarm optimization (PSO), bacteria foraging optimization (BFO), and teaching learning-based optimization (TLBO)) was brought into use in order to analyze the influence of the process parameters. In the end, an appropriate correlation between PSO, BFO, and TLBO was investigated. It was shown that RHVT improved the results by nearly 15% for all of the responses, while the TLBO technique was found to be the best optimization technique, with an average time of 1.09 s and a success rate of 90%

    Reimagining the future for retail and service design theory and practices

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    These proceedings were created by compiling the papers presented at the first colloquium of the Special Interest Group (SIG) Designing Retail & Service Futures from the Design Research Society (DRS). The SIG was established in 2021 under the guidance of the Design Research Society. The SIG strives to gain a better understanding of the value of design in the commercial sector, including disciplines, such as interior design, architecture, retail and hospitality, branding, marketing, strategic design, design management and consumer psychology. Design and its value have been a subject of study for many years and from many different disciplinary perspectives (ranging from product design to marketing, business economics, service design, management, environmental psychology, (interior)architecture, etc.). However, these perspectives have been developed in a fragmented way with discrete research methods and results that present limitations to practically applying these findings holistically across the inter-related fields of design, retail, and services. Recent developments, that have been accelerated by the pandemic and the current economic crisis, show that in practice, services are becoming integral to retail and vice versa. The consumers’ needs and the dedication of retailers to serve these needs have sparked new approaches that unite both service and retail design. Whether it be online or offline (or both), for a product or a service or an experience, or all together… It is only natural that the research community support the development of this field through furthering insights. This colloquium focuses on bringing together various disciplines to contribute their related knowledge and insights with the objective of calibrating terms and meanings that strive for consensus across disciplines related to retail and service design. This is to work towards knowledge and practice-based contributions that strive for a more holistic and encompassing retail and service design future

    FPGA-accelerated machine learning inference as a service for particle physics computing

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    New heterogeneous computing paradigms on dedicated hardware with increased parallelization, such as Field Programmable Gate Arrays (FPGAs), offer exciting solutions with large potential gains. The growing applications of machine learning algorithms in particle physics for simulation, reconstruction, and analysis are naturally deployed on such platforms. We demonstrate that the acceleration of machine learning inference as a web service represents a heterogeneous computing solution for particle physics experiments that potentially requires minimal modification to the current computing model. As examples, we retrain the ResNet-50 convolutional neural network to demonstrate state-of-the-art performance for top quark jet tagging at the LHC and apply a ResNet-50 model with transfer learning for neutrino event classification. Using Project Brainwave by Microsoft to accelerate the ResNet-50 image classification model, we achieve average inference times of 60 (10) milliseconds with our experimental physics software framework using Brainwave as a cloud (edge or on-premises) service, representing an improvement by a factor of approximately 30 (175) in model inference latency over traditional CPU inference in current experimental hardware. A single FPGA service accessed by many CPUs achieves a throughput of 600--700 inferences per second using an image batch of one, comparable to large batch-size GPU throughput and significantly better than small batch-size GPU throughput. Deployed as an edge or cloud service for the particle physics computing model, coprocessor accelerators can have a higher duty cycle and are potentially much more cost-effective.Comment: 16 pages, 14 figures, 2 table

    Internal cracks and non-metallic inclusions as root causes of casting failure in sugar mill roller shafts

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    The sugar mill roller shaft is one of the critical parts of the sugar industry. It requires careful manufacturing and testing in order to meet the stringent specification when it is used for applications under continuous fatigue and wear environments. For heavy industry, the manufacturing of such heavy parts (>600 mm diameter) is a challenge, owing to ease of occurrence of surface/subsurface cracks and inclusions that lead to the rejection of the final product. Therefore, the identification and continuous reduction of defects are inevitable tasks. If the defect activity is controlled, this offers the possibility to extend the component (sugar mill roller) life cycle and resistance to failure. The current study aims to explore the benefits of using ultrasonic testing (UT) to avoid the rejection of the shaft in heavy industry. This study performed a rigorous evaluation of defects through destructive and nondestructive quality checks in order to detect the causes and effects of rejection. The results gathered in this study depict macro-surface cracks and sub-surface microcracks. The results also found alumina and oxide type non-metallic inclusions, which led to surface/subsurface cracks and ultimately the rejection of the mill roller shaft. A root cause analysis (RCA) approach highlighted the refractory lining, the hot-top of the furnace and the ladle as significant causes of inclusions. The low-quality flux and refractory lining material of the furnace and the hot-top, which were possible causes of rejection, were replaced by standard materials with better quality, applied by their standardized procedure, to prevent this problem in future production. The feedback statistics, evaluated over more than one year, indicated that the rejection rate was reduced for defective production by up to 7.6%

    COVID-19 Pandemic and Initial Psychological Responses by Bangladeshi People

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    The present study was aimed to investigate the causes of COVID-19 worry and its effect on initial behaviors that observed in early stage of the COVID-19 outbreak in Bangladesh. In the online survey, participants’ were asked about normative concerns, COVID-19 worry, initial behaviors, and the neuroticism personality trait. Results of the study demonstrated that (i) higher normative concerns and neurotic trait were predictors of higher COVID-19 worry; and (ii) higher normative concerns and COVID-19 worry significant predictors of buying preparatory materials, higher worry for postponing travel plan, and higher worry and neuroticism for purchasing daily commodities more than usual and difficulties in concentration

    The role of urgent care centers in headache management: a quality improvement project

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    BACKGROUND: Patients with headache often seek urgent medical care to treat pain and associated symptoms that do not respond to therapeutic options at home. Urgent Cares (UCs) may be suitable for the evaluation and treatment of such patients but there is little data on how headache is evaluated in UC settings and what types of treatments are available. We conducted a study to evaluate the types of care available for patients with headache presenting to UCs. DESIGN: Cross-Sectional. METHODS: Headache specialists across the United States contacted UCs to collect data on a questionnaire. Questions asked about UC staffing (e.g. number and backgrounds of staff, hours of operation), average length of UC visits for headache, treatments and tests available for patients presenting with headache, and disposition including to the ED. RESULTS: Data from 10 UC programs comprised of 61 individual UC sites revealed: The vast majority (8/10; 80%) had diagnostic testing onsite for headache evaluation. A small majority (6/10; 60%) had the American Headache Society recommended intravenous medications for acute migraine available. Half (5/10) had a headache protocol in place. The majority (6/10; 60%) had no follow up policy after UC discharge. CONCLUSIONS: UCs have the potential to provide expedited care for patients presenting for evaluation and treatment of headache. However, considerable variability exists amongst UCs in their abilities to manage headaches. This study reveals many opportunities for future research including the development of protocols and professional partnerships to help guide the evaluation, triage, and treatment of patients with headache in UC settings
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