32 research outputs found

    Effect of different cooling strategies on surface quality and power consumption in finishing end milling of stainless steel 316

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    In this paper, an experimental investigation into the machinability of AISI 316 alloy during finishing end milling operation under different cooling conditions and with varying process parameters is presented. Three environmental-friendly cooling strategies were utilized, namely, dry, minimal quantity lubrication (MQL) and MQL with nanoparticles (Al2_{2}O3_{3}),and the variable process parameters were cutting speed and feed rate. Power consumption and surface quality were utilized as the machining responses to characterize the process performance. Surface quality was examined by evaluating the final surface roughness and surface integrity of the machined surface. The results revealed a reduction in power consumption when MQL and MQL + Al2_{2}O3_{3} strategies were applied compared to the dry case by averages of 4.7% and 8.6%, respectively. Besides, a considerable reduction in the surface roughness was noticed with average values of 40% and 44% for MQL and MQL + Al2_{2}O3_{3} strategies, respectively, when compared to the dry condition. At the same time, the reduction in generated surface roughness obtained by using MQL + Al2_{2}O3_{3}condition was marginal (5.9%) compared with using MQL condition. Moreover, the results showed that the improvement obtained in the surface quality when using MQL and MQL + Al2_{2}O3_{3} coolants increased at higher cutting speed and feed rate, and thus, higher productivity can be achieved without deteriorating final surface quality, compared to dry conditions. From scanning electron microscope (SEM) analysis, debris, furrows, plastic deformation irregular friction marks, and bores were found in the surface texture when machining under dry conditions. A slight smoother surface with a nano-polishing effect was found in the case of MQL + Al2_{2}O3_{3} compared to the MQL and dry cooling strategies. This proves the effectiveness of lubricant with nanoparticles in reducing the friction and thermal damages on the machined surface as the friction marks were still observed when machining with MQL comparable with the case of MQL + Al2_{2}O3_{3}

    On the Assessment of Surface Quality and Productivity Aspects in Precision Hard Turning of AISI 4340 Steel Alloy: Relative Performance of Wiper vs. Conventional Inserts

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    This article reports an experimental assessment of surface quality generated in the precision turning of AISI 4340 steel alloy using conventional round and wiper nose inserts for different cutting conditions. A three-factor (each at 4 levels) full factorial design of experiment was followed for feed rate, cutting speed, and depth of cut, with resulting machined surface quality characterized by resulting average roughness (Ra). The results show that, for the provided range of cutting conditions, lower surface roughness values were obtained using wiper inserts compared with conventional inserts, indicating a superior performance. When including the type of insert as a qualitative factor, ANOVA revealed that the type of insert was most important in determining surface roughness and material removal rate, with feed rate as the second most significant, followed by the interaction of feed rate and type of insert. It was found that using wiper inserts allowed simultaneous increases in feed rate, cutting speed, and depth of cut, while providing better surface quality of lower Ra, compared to the global minimum value that could be achieved using the conventional insert. These findings show that wiper inserts produce better surface quality and a material removal rate up to ten times higher than that obtained with conventional inserts. This clearly indicates the tremendous advantages of high surface quality and productivity that wiper inserts can offer when compared with the conventional round nose type in precision hard turning of AISI 4340 alloy steel

    Towards an Adaptive Design of Quality, Productivity and Economic Aspects When Machining AISI 4340 Steel With Wiper Inserts

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    The continuous pursue of sustainable manufacturing is motivating the utilization of new advanced technology, especially for hard to cut materials. In this study, an adaptive approach for optimization of machining process of AISI 4340 using wiper inserts is proposed. This approach is based on advance yet intuitive modeling and optimization techniques. The approach is based on Artificial Neural Network (ANN), Multi-Objective Genetic Algorithm (MOGA), as well as Linear Programming Techniques for Multidimensional Analysis of Preference (LINMAP), for modeling, optimization and multi-criteria decision making respectively. This integrated approach, to best of the authors’ knowledge, has been deployed for the first time to adaptively serve different designs of manufacturing processes. Such designs have different orientations, namely cost, quality, productivity, and balanced orientation. The capability of the proposed approach to serving such diverse requirements answers one of the most accelerating demands in the manufacturing community due to the dynamics of the uprising smart production lines. Besides, the proposed approach is presented in a straightforward manner that can be extended easily to other design orientations as well as other engineering applications. Based on the proposed design, a balanced general setting of 197.4 m/min, 0.95 mm, and 0.168 mm/rev was recommended along with other settings for more sophisticated requirements. Confirmatory experiments showed a good agreement (i.e., no more than 7% deviation) with the predicted optimum responses. This shows the validity of the proposed approach as a viable tool for designers to promote holistic and sustainable process design

    SURVEY BASE STUDY ON CURRENT TREND OF TREATMENT OF COMMUNITY-ACQUIRED PNEUMONIA IN KARACHI

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    Objective: Community-acquired pneumonia (CAP) is a potentially serious infection that results in various general physicians (GP) visits and hospital admission every year. The prime objective of this research was to find the current trend of treatment of community-acquired pneumonia in Karachi.Methods: It was a prospective survey conducted in all districts of Karachi. A Questionnaire was filled by distinctive specialities of doctors in an outpatient setting in Karachi. A preliminary test questionnaire was used to collect the data directly from distinctive specialities of doctors in outpatient setting in Karachi. Total 500 doctors were selected from distinct districts of Karachi with convenient random sampling.Results: Majority (33.8%) of the respondents recommended complete blood count and chest x-ray for diagnosis of community-acquired pneumonia in an outpatient setting. Most (76%) of the respondents recommended nebulization for the management of community-acquired pneumonia in an outpatient setting. 31% and 25.4% of the physicians recommended clarithromycin as 1st line antibiotic therapy in adults and children for the management of a community-acquired pneumonia patients in outpatient setting.55.6% of the physicians recommended two-week duration of antibiotic therapy for the management of CAP in outpatient setting.Conclusion: This is clearly indicated by this study that deviation from the standard guideline is observed in the management of community-acquired pneumonia in Karachi. These deviations from the highly recommended guideline can results excess cost and inappropriateness of the management of the disease of community-acquired pneumonia. There is a need that the physician should take a decision of therapy according to the standard guidelines for the treatment of CAP in an outpatient setting.Â

    Variants of CTGF are associated with hepatic fibrosis in Chinese, Sudanese, and Brazilians infected with Schistosomes

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    Abnormal fibrosis occurs during chronic hepatic inflammations and is the principal cause of death in hepatitis C virus and schistosome infections. Hepatic fibrosis (HF) may develop either slowly or rapidly in schistosome-infected subjects. This depends, in part, on a major genetic control exerted by genes of chromosome 6q23. A gene (connective tissue growth factor [CTGF]) is located in that region that encodes a strongly fibrogenic molecule. We show that the single nucleotide polymorphism (SNP) rs9402373 that lies close to CTGF is associated with severe HF (P = 2 × 10−6; odds ratio [OR] = 2.01; confidence interval of OR [CI] = 1.51–2.7) in two Chinese samples, in Sudanese, and in Brazilians infected with either Schistosoma japonicum or S. mansoni. Furthermore, SNP rs12526196, also located close to CTGF, is independently associated with severe fibrosis (P = 6 × 10−4; OR = 1.94; CI = 1.32–2.82) in the Chinese and Sudanese subjects. Both variants affect nuclear factor binding and may alter gene transcription or transcript stability. The identified variants may be valuable markers for the prediction of disease progression, and identify a critical step in the development of HF that could be a target for chemotherapy

    Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

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    Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

    Measuring the health-related Sustainable Development Goals in 188 countries: a baseline analysis from the Global Burden of Disease Study 2015

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    BACKGROUND: In September, 2015, the UN General Assembly established the Sustainable Development Goals (SDGs). The SDGs specify 17 universal goals, 169 targets, and 230 indicators leading up to 2030 ..

    Measuring the health-related Sustainable Development Goals in 188 countries : a baseline analysis from the Global Burden of Disease Study 2015

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    Background In September, 2015, the UN General Assembly established the Sustainable Development Goals (SDGs). The SDGs specify 17 universal goals, 169 targets, and 230 indicators leading up to 2030. We provide an analysis of 33 health-related SDG indicators based on the Global Burden of Diseases, Injuries, and Risk Factors Study 2015 (GBD 2015). Methods We applied statistical methods to systematically compiled data to estimate the performance of 33 health-related SDG indicators for 188 countries from 1990 to 2015. We rescaled each indicator on a scale from 0 (worst observed value between 1990 and 2015) to 100 (best observed). Indices representing all 33 health-related SDG indicators (health-related SDG index), health-related SDG indicators included in the Millennium Development Goals (MDG index), and health-related indicators not included in the MDGs (non-MDG index) were computed as the geometric mean of the rescaled indicators by SDG target. We used spline regressions to examine the relations between the Socio-demographic Index (SDI, a summary measure based on average income per person, educational attainment, and total fertility rate) and each of the health-related SDG indicators and indices. Findings In 2015, the median health-related SDG index was 59.3 (95% uncertainty interval 56.8-61.8) and varied widely by country, ranging from 85.5 (84.2-86.5) in Iceland to 20.4 (15.4-24.9) in Central African Republic. SDI was a good predictor of the health-related SDG index (r(2) = 0.88) and the MDG index (r(2) = 0.2), whereas the non-MDG index had a weaker relation with SDI (r(2) = 0.79). Between 2000 and 2015, the health-related SDG index improved by a median of 7.9 (IQR 5.0-10.4), and gains on the MDG index (a median change of 10.0 [6.7-13.1]) exceeded that of the non-MDG index (a median change of 5.5 [2.1-8.9]). Since 2000, pronounced progress occurred for indicators such as met need with modern contraception, under-5 mortality, and neonatal mortality, as well as the indicator for universal health coverage tracer interventions. Moderate improvements were found for indicators such as HIV and tuberculosis incidence, minimal changes for hepatitis B incidence took place, and childhood overweight considerably worsened. Interpretation GBD provides an independent, comparable avenue for monitoring progress towards the health-related SDGs. Our analysis not only highlights the importance of income, education, and fertility as drivers of health improvement but also emphasises that investments in these areas alone will not be sufficient. Although considerable progress on the health-related MDG indicators has been made, these gains will need to be sustained and, in many cases, accelerated to achieve the ambitious SDG targets. The minimal improvement in or worsening of health-related indicators beyond the MDGs highlight the need for additional resources to effectively address the expanded scope of the health-related SDGs.Peer reviewe

    Monis Ahmed Hasan Speaks on Discrimination Post 9/11

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    The time that I spent unemployed in New York City before & after 9/11 was a year and a half. I was visited by the FBI & NYPD about 2-3 weeks after that date. They had already visited my office and questioned my colleagues in private about me before coming to my apartment at 7 am. They had a big document with my history and asked me questions about my religious beliefs, and relationships with the local Muslim community. That was a very nerve-wracking time for me & my brothers. But they were satisfied with my answers and left. Although I was on an H1B visa and recently laid off so my immigration status was in limbo. And I, therefore, had to rush to a Lawyer the same day to file paperwork to keep me legal, the cost of which was very painful to me in my unemployment. But I did it to avoid being thrown in jail like many others. During that time I went through extreme lows and highs as I tried to find a job and fight off the negative discrimination that resulted against Muslims in all spheres of life. An example of that was when I had three separate job offers or interests revoked because of immigration issues cited by the employer. Employers like Jetblue Airways, CIT Capital Aviation, and Sabre Consulting were employers that backed away. Aviation in America had ended as a potential career for me in those months. But thank god for Dubai where I was from and which allowed me to continue work in that sector at Emirates Airlines. But today I have decided to focus on the Technology & Startup sector in UAE as I see a much greater potential for my economic future in it. Personally, the event did change my life trajectory. I had planned to naturalize as an American citizen, complete a graduate degree, and continue living as an American for the future. But all the signals I got from God and fate was that it was not the right time for me to be there. I love New York City for its energy and did not want to leave. It was one of my most difficult times as a Muslim. But it was also the time when I matured. The months after 9/11 were life-changing for the entire world but especially for the people of New York. The time I had in the aftermath was used to fall in love with the wounded city and with myself. I saw and experienced so many areas, events, and cultures of the big apple during that time that I would almost award myself a second bachelor’s degree for that
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