检索结果-南通市图书馆

Effect of friction stir processing on mechanical properties and heat transfer of TIG welded joint of AA6061 and AA7075

2009年

作者： by r.K. mishra.

来源：畅想之星图书光盘版（南... 评论

在线全文

畅想之星图书光盘版（南通市图书馆镜像）

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2021年第3期17卷 715-727页

作者： Husain Mehdi r.S.mishra Department of Mechanical Engineering Delhi Technological UniversityDelhiIndia

Tungsten inert gas(TIG) welding is the most commonly used joining process for aluminum alloy for AA6061 and AA7075 which are highly demanded in the aerospace engineering and the automobile sector, but there are some defects occur during TIG welding like micro-crack, coarse grain structure, and porosity. To improve these defects, the TIG welded joint is processed using friction stir processing(FSP).This paper presents the effect of friction stir processing on TIG welding with filler Er4043 and Er 5356 for dissimilar aluminum alloy AA6061 and AA7075. The mechanical characterization, finite element formulation and mathematical equations of heat transfer of TIG + FSP welded joints are investigated using ANSYS Fluent software by adjusting process parameters of FSP. The results show that the maximum compressive residual stress 73 MPa was obtained at the fusion zone(FZ) of the TIG weldment with filler Er4043, whereas minimum compressive residual stress 37 MPa was obtained at stir zone(SZ) of the TIG+ FSP with filler 5356. The maximum heat flux 5.33 × 106 W/m2 and temperature 515C have observed at tool rotation 1600 rpm with a feed rate of 63 mm/min. These results give a satisfactory measure of confidence in the fidelity of the simulation。

关键词： residual stress TIG+FSW Heat transfer Micro-hardness Tensile strength

Effect of ankle versus thigh tourniquets on post-operative pain in foot and ankle surgery

在线全文

学校读者我要写书评

暂无评论

World Journal of Orthopedics 2024年第2期15卷 163-169页

作者： Ashish mishra Ahmed Barakat Jitendra Mangwani Jakub Kazda Sagar Tiwatane Sana Mohammed Aamir Shaikh Linzy Houchen-Wolloff Vipul Kaushik Department of Trauma and Orthopedics University Hospitals LeicesterLeicester LE15WWUnited Kingdom Department of Trauma and Orthopedics Leicester University Hospitals-NHS TrustLeicester LE15WWLeicestershireUnited Kingdom Academic Team of Musculoskeletal Surgery University Hospitals of Leicester NHS TrustLeicester LE39QPUnited Kingdom Department of Anaesthesia York&Scarborough Teaching Hospitals NHS Foundation TrustNorth Yorkshire YO318HEUnited Kingdom Department of Anaesthesia Royal Free London NHS TrustLondon NW32QGUnited Kingdom Department of Trauma&Orthopaedics Breach Candy Hospital TrustMumbai 400026India Department of Physiotherapy University Hospitals of Leicester NHS TrustLeicester LE39QPUnited Kingdom Department of Anasthesia University Hospitals of Leicester NHS TrustLeicester LE15WWUnited Kingdom

BACKGrOUND Tourniquets are commonly used in elective extremity orthopaedic surgery to reduce blood loss,improve visualization in the surgical field,and to potentially reduce surgical *** is a lack of consensus in existing guidelines regarding the optimal tourniquet pressure,placement site,and duration of *** is a paucity of data on the relationship between the site of a tourniquet and postoperative pain in foot and ankle *** To explore the relationship between tourniquet site and intensity of post-operative pain scores in patients undergoing elective foot and ankle *** retrospective analysis of prospectively collected data on 201 patients who underwent foot and ankle surgery in a single institution was *** tourniquet duration,tourniquet pressure and site,and postoperative pain scores using Visual Analogue Score were collected in immediate recovery,at six hours and at 24 h *** plots were used to analyse the data and to assess for the statistical correlation between tourniquet pressure,duration,site,and pain scores using Pearson correlation *** All patients who underwent foot and ankle surgery had tourniquet pressure of 250 mmHg for ankle tourniquet and 300 mmHg for *** was no correlation between the site of the tourniquet and pain scores in recovery,at six hours and after 24 *** was a weak correlation between tourniquet time and Visual Analogue Score immediately post-op(r=0.14,P=0.04)but not at six or 24 h *** This study shows that there was no statistically significant correlation between tourniquet pressure,site and postop pain in patients undergoing foot and ankle *** choice of using a tourniquet is based on the surgeon's preference,with the goal of minimizing the duration of its application at the operative site.

关键词： Lower limb surgery Tourniquet time Tourniquet pressure Tourniquet site Post-operative pain Pain scores

Motion of a permeable shell in a spherical container filled with non-Newtonian fluid

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2017年第12期38卷 1697-1708页

作者： V.mishra B.r.GUPTA Department of Mathematics Jaypee University of Engineering and TechnologyMadhya Pradesh 473226India

This paper presents an analytical study of creeping motion of a permeable sphere in a spherical container filled with a micro-polar fluid. The drag experienced by the permeable sphere when it passes through the center of the spherical container is studied. Stream function solutions for the flow fields are obtained in terms of modified Bessel functions and Gegenbauer functions. The pressure fields, the micro-rotation components, the drag experienced by a permeable sphere, the wall correction factor, and the flow rate through the permeable surface are obtained for the frictionless impermeable spherical container and the zero shear stress at the impermeable spherical container. Variations of the drag force and the wall correction factor with respect to different fluid parameters are studied. It is observed that the drag force, the wall correction factor, and the flow rate are greater for the frictionless impermeable spherical container than the zero shear stress at the impermeable spherical container. Several cases of interest are deduced from the present analysis.

关键词： micro-polar fluid permeable sphere Darcy law stream function drag force wall correction factor spherical container

Paradigm shift in transfusion practices during early COVID-19 pandemic:A single center retrospective study

在线全文

学校读者我要写书评

暂无评论

World Journal of Virology 2024年第2期13卷 78-86页

作者： Sumukh Arun Kumar Sushmita Prabhu Ankushi Sanghvi Maya Gogtay Mithil Gowda Suresh Harshit Khosla Yuvaraj Singh Ajay Kumar mishra Susan George Department of Internal Medicine Saint Vincent HospitalWorcesterMA 01608United States Department of Hematology and Oncology University of Nebraska Medical CenterOmahaNE 68198United States Hospice and Palliative Care UTHSC and McGovern School of MedicineTexasTX 77030United States Department of Gastroenterology and Hepatology UMass Chan Medical SchoolWorcesterMA 01655United States Division of Cardiology Saint Vincent HospitalWorcesterMA 01608United States

BACKGrOUND The advent of coronavirus disease 2019(COVID-19)unveiled the worst national blood crisis that the United States had witnessed in over a *** the pandemic influencing the different stages of the acquisition of blood products outside the hospital setting,we aimed to explore the possible barriers contributing to the shortage of blood products within the medical *** COVID era and pre-COVID *** We conducted a retrospective cross-sectional study on hospitalized patients distinguishing the pattern of blood transfusion during the COVID and pre-COVID era in a community *** was tabulated to include the number of red blood cell(rBC)transfusions and if transfusions met restrictive blood transfusion criteria as per institutional ***-square was applied to test the statistical association between qualitative *** t test and Mann Whitney U test were applied respectively to test the mean difference of quantitative *** A total of 208 patients were included in the study,of which 108 were during COVID era and 100 were during pre-COVID *** leading reason for admission in both the COVID era and pre-COVID era transfused patients was shortness of breath(53.7%and 36%P=0.001),followed by gastrointestinal bleeding(25.9%and 21%P=0.001).There was a higher percentage of rBC transfusions in the intensive care unit in the COVID-era group than in the pre-COVID era group(38.9%vs 22%,P=0.008).The restrictive transfusion criteria were met in 62%vs 79%in the COVID and pre-COVID eras,respectively(P=0.008).CONCLUSION The COVID-era group received rBC transfusions with less stringent adherence to restrictive blood transfusion practices in comparison to pre-COVID era group.

关键词： Blood transfusion restrictive transfusion COVID-19 Pre-COVID-19 Blood shortage Pandemic

Saddle Point Criteria in Nonsmooth Semi-Infinite Minimax Fractional Programming Problems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2018年第2期31卷 446-462页

作者： mishra S K SINGH Yadvendra VErMA r U Department of Mathematics Banaras Hindu University Varanasi-221005 India. Department of Mathematics Texas State University USA

This paper considers a nonsmooth semi-infinite minimax fractional programming problem（SIMFP） involving locally Lipschitz invex functions. The authors establish necessary optimality conditions for SIMFP. The authors establish the relationship between an optimal solution of SIMFP and saddle point of scalar Lagrange function for SIMFP. Further, the authors study saddle point criteria of a vector Lagrange function defined for SIMFP.

关键词： Generalized convexity Lagrange function nonsmooth programming problems saddlepoint semi-infinite minimax fractional programming problems.

Evaluation of flocculation characteristics of kaolinite dispersion system using guar gum:A green flocculant

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2019年第5期29卷 745-755页

作者： r.K.Dwari B.K.mishra Mineral Processing Department CSIR-Institute of Minerals and Materials TechnologyBhubaneswar 751013India Indian Institute of Technology Goa 403401India

This paper reports the systematic investigation on the flocculation,sedimentation and consolidation characteristics of kaolinite using guar gum as a green ***-situ flocculation behavior of kaolinite at various pH,guar gum dosages,and ionic strength were studied using a light scattering *** effect of these parameters on the settling rate,solid consolidation,and supernatant liquid clarity was *** morphology of kaolinite and flocculated kaolinite aggregates were analyzed using *** morphology studies suggest that it is poorly crystalline with multiple steps on edge,broken edge;laminar with high aspect ratio and have rough basal *** complex irregularity on the basal surface and the presence of multiple steps in the edges,broken edges(hydroxyl groups)have facilitated the guar gum *** isoelectric point of kaolinite is pH *** pH,ionic strength and flocculant dosage have a significant effect on the kaolinite settling *** guar gum has exhibited excellent turbidity removal efficiency at pH *** turbidity removal is inefficient at pH ***,guar gum has shown high turbidity removal with 80%transmission at pH 10 in the presence of a KNO3 electrolyte.

关键词： Guar gum Dewatering Kaolinite Light scattering Morphology Flocculation

Simultaneous effects of chemical reaction and Ohmic heating with heat and mass transfer over a stretching surface: A numerical study

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2017年第9期25卷 1137-1142页

作者： S.r.mishra M.M.Bhatti Department of Mathematics Siksha ‘O’ Anusandhan University Shanghai Institute of Applied Mathematics and Mechanics Shanghai University

In this article, we have considered the simultaneous influence of ohmic heating and chemical reaction on heat and mass transfer over a stretching sheet. The effects of applied magnetic field are also taken into consideration while the induced magnetic field is not considered due to very small magnetics reynolds number. The governing flow problem comprises of momentum, continuity, thermal energy and concentration equation which are transformed into highly nonlinear coupled ordinary differential equations by means of similarity transforms, which are then, solved numerically with the help of Successive Linearization method(SLM) and Chebyshev Spectral collocation method. Numerical values of skin friction coefficient, local Nusselt number, and Sherwood number are also taken into account with the help of tables. The physical influence of the involved parameters of flow velocity, temperature and concentration distribution is discussed and demonstrated graphically. The numerical comparison is also presented with the existing published results and found that the present results are in excellent agreement which also confirms the validity of the present methodology.

关键词： Ohmic heating Heat and mass transfer Chemical reaction Successive linearization method

Two-Stent Strategy for Bifurcation Lesions in Percutaneous Transluminal Coronary Angioplasty: real-World Evidence

在线全文

学校读者我要写书评

暂无评论

World Journal of Cardiovascular Diseases 2024年第3期14卷 140-156页

作者： Dilip Kumar Amit Malviya Animesh mishra rabin Chakraborty Sanjeev S. Mukherjee Soumya Patra Arindam Pande rana rathor roy Debopriyo Mondal Ashesh Halder Sumit Shanker Medica Superspecialty Hospital 127 Eastern Metropolitan Bypass Nitai Nagar Mukundapur Kolkata West Bengal India North Eastern Indira Gandhi regional Institute of Health & Medical Sciences (NEIGrIHMS) Mawdiangdiang Shillong Meghalaya India

Background: Bifurcation lesions pose a high risk for adverse events after percutaneous coronary intervention (PCI). Evidence supporting the benefits of the two-stent strategy (2SS) for treating coronary bifurcation lesions in India is limited. This study aimed to evaluate the clinical outcomes of various 2SSs for percutaneous transluminal coronary angioplasty for bifurcation lesions in India. Materials and Methods: This retrospective, observational, multicentric, real-world study included 64 patients over 8 years. Data on demographics, medical history, PCI procedures, and outcomes were recorded. Descriptive statistics were computed using the SPSS software. results: Patients (n = 64) had an average age of 65.3 ± 11.1 years, with 78.1% males. Acute coronary syndrome was reported in 18.8%, chronic stable angina in 40.6%, and unstable angina in 34.4% of participants. Two-vessel disease was observed in 98.4% of patients, and 99.4% had true bifurcation lesions. The commonly involved vessels were the left anterior descending artery (50%), left circumflex coronary artery (34.4%), and first diagonal artery (43.8%). Mean percent diameter stenosis was 87.2% ± 10.1%. The mean number of stents used was 2.00 ± 0.34. The 2SS techniques included the T and small protrusion (TAP) (39.1%), double kissing (DK) crush (18.8%), and the culotte techniques (14.1%). Procedural and angiographic success rate was 92.18%. Major adverse cardiovascular events at 1-year follow-up occurred in 7.8% of cases. Conclusion: The 2SS for bifurcation lesions showed favorable in-hospital and follow-up outcomes. Findings can serve as a resource for bifurcation angioplasty in India. Larger real-world studies with robust methodology are needed to validate these results.

关键词： Bifurcation Stenting Coronary Bifurcation Lesions Percutaneous

Effect of orientation on the drag of a cone settling in a Bingham plastic fluid

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2019年第2期17卷 157-170页

作者： Pragya mishra A.K. Tiwari r.P. Chhabra Department of Chemical Engineering. Indian Institute of Technology Kanpur 208016 India M2NeT Laboratory Wilfrid Laurier University 75 University Avenue West Waterloo ON N2L 3C5 Canada

Effects of the orientation and apex angle on the settling velocity of conical particles in Bingham plas-tic fluids are numerically investigated over a reynolds number range of 1 ≤re ≤100, Bingham number range of 0 ≤ Bn ≤ 100, and cone angle range of 20 ≤α≤ 150°. Governing equations (of continuity and momentum) are solved numerically using the finite element method to obtain velocity and pressure fields that are postprocessed to obtain values of the drag ***, the effect of cone ori-entation on the flow field is visualized and explored in terms of streamline contours and the morphology of yielded/uny ielded regions. Finally, the obtai ned values of drag are correlated via a simple predictive expression in terms of the modified reynolds number. The effect of the cone angle on drag is found to be moderate because the drag force acting on the lateral surface is a small fraction of the overall drag.

关键词： Bingham number reynolds number Yielded/unyielded regions Drag