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Journal of Minerals and Materials Characterization and Engineering 2011年第3期10卷 231-244页

作者： Mohammad Asif K. Chandra p.s. misra Metallurgical and Materials Engineering Department Indian Institute of TechnologyRoorkee. Roorkee- 247667 India

A promising friction material, Iron -based friction material, was prepared by powder metallurgy (pM) processing utilizing hot powder preform forging (near net-shape).The preparation of the product and its characterization are presented in this paper. These products are useful in heavy duty Military Aircraft applications such as AN-32. In order to eliminate costly environmental control systems to protect products during their high temperature processing (as is conventionally practiced employing hydrogen gas), the present investigation relies on carbon (mixed in the brake pad formulation) as reducing agent and high temperature oxidation resistant glassy coating (separately developed) applied over the product’s surface after cold compacting. After conducting an initial characterization such as hardness, density and pin-on Disc tests, the samples were tested in sub-scale dynamometer under Rejected Take Off conditions. It was observed that the obtained density in the present investigation is higher than the reported density obtained by sintering route, and wear is on the lower side of the range as per the Aeronautical standards. Optical metallography was used to investigate the microstructure of friction, interface and backing layer. It was observed that the distribution of ingredients in matrix was homogeneous. The results also indicate that the coefficient of friction is more stable, and wear is lower with respect to temperature rise. .

关键词： Forging powder Metallurgy Friction material brake pad

Development of Iron Based Brake Friction MMC Used for Military Aircraft Application by A New p/M Route

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Journal of Minerals and Materials Characterization and Engineering 2011年第8期10卷 693-705页

作者： Mohammad Asif K. Chandra p.s. misra Metallurgical and Materials Engineering Department Indian Institute of Technology Roorkee.Roorkee- 247667 India

A new p/M route based hot powder pre-form forging process has been evolved to develop high density brake materials for heavy duty applications. Number of iron based MMC’s so developed offer better characteristics for braking applications in comparison to the materials developed through conventional p/M route based on high pressure compaction and pressure sintering. The process so developed in the present investigations is much simpler and easy to adopt by existing p/M industries. Hot powder pre-form forging technique for making heavy duty brake pads offers better opportunity for pore free material with better bonding between various metallic and non-metallic constituents. After conducting an initial characterization such as hardness, density and pin-on Disc tests, the samples were tested for high energy (32,933kgfm) on sub-scale dynamometer under Rejected Take Off conditions. The results have also been compared with respect to brake pads employed in heavy duty Military aircraft tested under identical laboratory conditions. The present work indicates that the newly developed materials compare better than the one being currently employed in heavy duty aircraft. The reasons for better performance are improved processing technique and resulting higher levels of density and improved binding of the product.

关键词： brake pad heavy duty Aircraft brakes powder Metallurgy.

Development and Characterization of Fe-Based Friction Material Made by Hot powder preform Forging for Low Duty Applications

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Journal of Minerals and Materials Characterization and Engineering 2011年第13期10卷 1205-1212页

作者： A.A.s. Ghazi K. Chandra p.s. misra Department of Metallurgical and Materials Engineering Indian Institute of Technology Roorkee India.

This present paper investigates the friction and wear properties of friction material developed by ‘Hot powder preform Forging’ technique. The conventional technique to manufacture Metallo-ceramic brake pads was successfully and economically tried to replace the above process. Compacting and sintering technology suffers from certain major limitations such as inadequate joining of friction element with backing plate, poor density levels achieved in friction element owing to limited application of pressure during compacting, poor thermal conductivity due to high levels of porosity in the product, poor strength due to segregation of the impurities along prior particle boundaries (ppB’s) and, wide variations in final characteristics due to large number of variables involved. In contrast to these limitations, the present technique can offer brake pads of much simpler chemistry but with improved performance on account of simultaneous application of pressure and temperature and with better control of variables. Fade and recovery studies were carried out on a Krauss machine tester following the Economic Commission for Europe Regulation for replacement brake linings (ECE R-90). μfade, μrecovery, μperformance, % age fade , % age recovery & temperature rise lie within the range for friction materials used for low duty applications. The mechanical properties of these materials were characterized using AsTM standards.

关键词： Friction material preform forging Brake pads Fade.

Mechanical properties of powder Based steel used as Backing plate in Heavy Duty Brake pad Manufacturing

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Journal of Minerals and Materials Characterization and Engineering 2012年第5期11卷 509-518页

作者： M. Asif K. Chandra p.s. misra Department of Metallurgical and Materials EngineeringIndian Institute of Technology Roorkee Roorkee – 247667 (INDIA)

The aims of the present study is to develop a powder based steel used as backing plate for heavy duty brake pad applications. Three powder based back plate steel comp.s.tions namely B1 (C- 0.3, Cu – 1.5, p -0.3, Fe – 97.9), B2 (C- 0.1, Cu – 2.5, siC-1, Fe – 96.4) and B3(C- 0.5, Cu – 2.5, siC-1, Fe – 96.0) were prepared using a hot powder preform forging technique. The forged samples are of (25× 50×10 mm3) dimensions. These samples were hot rolled and annealed to relieve the residual stresses. These samples were characterized in terms of microstructure, porosity content/densification, hardness and tensile properties. Densification as high near to theoretical density has been realized. Hot powder preform forging using closed die showed better densification. Rolled and annealed microstructure showed lesser porosity content than the forged one. phosphorous causes hardening of ferrite in solid solution with iron. Comp.s.tions B1, showed reasonable elongation and it improved further on annealing. It was observed in this present investigation that, the addition, such as siC and Cu caused increase in strength. steel developed in the investigation are used as powder based backing plate in Manufacturing of iron based brake pads used in heavy duty applications.

关键词： powder based steel brake pad manufacturing Mechanical properties

Development of Aluminium Based Hybrid Metal Matrix Comp.s.tes for Heavy Duty Applications

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Journal of Minerals and Materials Characterization and Engineering 2011年第14期10卷 1337-1344页

作者： M. Asif K. Chandra p.s. misra Department of Metallurgical and Materials Engineering Indian Institute of Technology Roorkee Roorkee – 247667 (INDIA)

The present study deals with the investigation of dry sliding wear behavior of aluminium alloy based comp.s.tes, reinforced with silicon carbide particles and solid lubricants such as graphite/antimony tri sulphide (sb2s3). The first one of the comp.s.tes (binary) consists of Al. with 20% silicon Carbide particles (siCp) only. The other comp.s.te has siCp and solid lubricants: Graphite + sb2s3 (hybrid comp.s.te) at solid state. Both comp.s.tes are fabricated through p/M route using “Hot powder perform forging technology”. The density and hardness are measured by usual methods. The pin-on-disc dry wear tests to measure the tribological properties are conducted for one hour at different parameters namely load: 30, 50 and 80N and speed: 5, 7 and 9m/s. The tested samples are examined using scanning electron microscope (sEM) for the characterization of microstructure and tribolayer on worn surface of comp.s.tes. The results reveal that wear rate of hybrid comp.s.te is lower than that of binary comp.s.te. The wear rate decreased with the increasing load and increased with increasing speed. The results of the prop.s.d comp.s.tes are compared with iron based metal matrix comp.s.tes (FM01N, FM02) at corresponding values of test parameters. These iron based metal matrix comp.s.tes are also fabricated by p/M route using ‘Hot powder perform forging technology’. The comparative study reveals that the prop.s.d comp.s.tes have lower friction coefficient, less temperature rise and low noise level;however they have little higher wear rate. It is concluded that the hybrid comp.s.te has acceptable level of tribological characteristics with blacky and smooth worn surface.

关键词： Al-MMC powder Metallurgy powder Forging Heavy Duty applications.

Quantification of grain boundary effects on the geometrically necessary dislocation density evolution and strain hardening of polycrystalline Mg-4Al using in situ tensile testing in scanning electron microscope and HR-EBsD

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Journal of Magnesium and Alloys 2024年第5期12卷 1815-1829页

作者： Eunji song Mohsen Taheri Andani Amit misra Department of Materials science and Engineering University of MichiganAnn ArborMI 48109USA Department of Mechanical Engineering University of MichiganAnn ArborMI 48109USA Department of Mechanical Engineering Texas A&M UniversityCollege StationTX 77843USA

In situ tensile testing in a scanning electron microscope(sEM)in conjunction with high-resolution electron backscatter diffraction(HR-EBsD)under load was used to characterize the evolution of geometrically necessary dislocation(GND)densities at individual grain boundaries as a function of applied strain in a polycrystalline Mg-4Al *** increase in GND density was investigated at plastic strains of 0%,0.6%,2.2%,3.3% from the area including 76 grains and correlated with(i)geometric compatibility between slip.s.stems across grain boundaries,and(ii)plastic *** develop expressions for the grain boundary GND density evolution as a function of plastic strain and plastic incompatibility,from which uniaxial tensile stress-strain response of polycrystalline Mg-4Al are computed and compared with experimental *** findings in this study contribute to understanding the mechanisms governing the strain hardening response of single-phase polycrystalline alloys and more reliable prediction of mechanical behaviors in diverse microstructures.

关键词： Mg-Al alloys Grain boundaries Geometrically necessary dislocations strain gradient plasticity HR-EBsD

Flavonoid Myricetin as potent Anticancer Agent: A p.s.ibility towards Development of potential Anticancer Nutraceuticals

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Chinese Journal of Integrative Medicine 2024年第1期30卷 75-84页

作者： Anchal Trivedi Adria Hasan Rumana Ahmad sahabjada siddiqui Aditi srivastava Aparna misra snober s.Mir Department of Biochemistry Era's Lucknow Medical College&HospitalEra UniversityLucknow(226003)India Molecular Cell Biology Laboratory Integral Information and Research Centre-4(IIRC-4)Department of BioengineeringFaculty of EngineeringIntegral UniversityLucknow(226026)India Department of Biotechnology Era's Lucknow Medical College&HospitalEra UniversityLucknow(226003)India Department of Biosciences Faculty of ScienceIntegral UniversityLucknow(226026)India

Good nutrition plays a crucial role in maintaining a balanced lifestyle. The beneficial effects of nutrition have been found to counteract nutritional disturbances with the expanded use of nutraceuticals to treat and manage cardiovascular diseases, cancer, and other developmental defects over the last decade. Flavonoids are found abundantly in plant-derived foods such as fruits, vegetables, tea, cocoa, and wine. Fruits and vegetables contain phytochemicals like flavonoids, phenolics, alkaloids, saponins, and terpenoids. Flavonoids can act as anti-inflammatory, anti-allergic, anti-microbial(antibacterial, antifungal, and antiviral) antioxidant, anti-cancer, and anti-diarrheal agents. Flavonoids are also reported to upregulate apoptotic activity in several cancers such as hepatic, pancreatic, breast, esophageal, and colon. Myricetin is a flavonol which is naturally present in fruits and vegetables and has shown p.s.ible nutraceutical value. Myricetin has been portrayed as a potent nutraceutical that may protect against cancer. The focus of the present review is to present an updated account of studies demonstrating the anticancer potential of myricetin and the molecular mechanisms involved therein. A better understanding of the molecular mechanism(s) underlying its anticancer activity would eventually help in its development as a novel anticancer nutraceutical having minimal side effects.

关键词： myricetin flavonoids anticancer nutraceuticals Chinese medicine Ayurveda complementary and alternative medicine

Long Term X-Ray spectral Variations of the seyfert-1 Galaxy Mrk 279

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Research in Astronomy and Astrophysics 2024年第6期24卷 307-314页

作者： K.Akhila Ranjeev misra savithri H.Ezhikode K.Jeena Department of physics Providence Women’s CollegeUniversity of CalicutKerala 673009India Inter-University Centre for Astronomy and Astrophysics(IUCAA) PB No.4GaneshkhindPune 411007India Department of physics and Electronics CHRIST(Deemed to be University)Hosur Main RoadBangalore 560029India

We present the results from a long term X-ray analysis of Mrk 279 during the period 2018–*** use data from multiple missions–Astrosat,NusTAR and XMM-Newton,for the *** X-ray spectrum can be modeled as a double Comptonization along with the presence of neutral Fe Kαline emission,at all *** determined the source’s X-ray flux and luminosity at these different *** find significant variations in the source’s flux *** also investigate the variations in the source’s spectral components during the observation *** find that the photon index and hence the spectral shape follow the variations only over longer time *** probe the correlations between fluxes of different bands and their photon indices,and found no significant correlations between the parameters.

关键词： galaxies:seyfert galaxies:individual(Mrk 335) X-rays:galaxies

A Case Report of Bartonella henselae Infection Causing Fever of Unknown Origin: Unveiling a stealthy pathogen

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Open Journal of Internal Medicine 2024年第3期14卷 269-277页

作者： Neeladri misra Medical plaza Dr Sutter Roseville Medical Center Roseville CA USA

Bartonella species are bacterial pathogens responsible for Cat scratch Disease (CsD) with various clinical manifestations, ranging from self-limiting febrile illnesses to severe systemic infections. Diagnosis is often challenging due to its insidious nature and variable presentation based on the body’s immune status. such a scenario emerged when a 25-year-old male presented to our hospital with nonspecific symptoms of Fever of unknown origin that were not responding to antibiotics until a timely diagnosis of Bartonella infection. This case report highlights the importance of considering Bartonella as a potential etiology in patients with prolonged Fever of unknown origin, especially in endemic regions.

关键词： Bartonella henselae Cat scratch Disease Lymphadenopathy Immunocompetent Cat Endocarditis Doxycycline Rifampin

A Comprehensive Analysis of Efficacy and safety of probiotics in Inflammatory Bowel Disease

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Open Journal of Gastroenterology 2024年第6期14卷 213-225页

作者： Feruza Abraamyan Neeladri misra sutter Roseville Medical Center Roseville California USA

Introduction: Inflammatory bowel disease (IBD) affects approximately 7 million people worldwide. In the U.s. alone, per the CDC, 1.3% of adults, which is approximately 3,000,000 people, are diagnosed with inflammatory bowel disease-either, Crohn’s disease, or ulcerative colitis. The estimated cost of treatment can be close to $23,000 annually, with treatment regimens comprising biologic agents and anti-inflammatory therapies. probiotics have recently gathered interest as a low-cost additional therapy option that, in addition to the current regimen of IBD management, allows for reductions in rates of IBD flare-ups by significantly reducing the number of emergency room visits and avoiding the need to constantly escalate treatment by addition of biologic agents in achieving remission. The Analysis Goal: Our research project aimed to see if there was a significant difference in the addition of probiotics to standard therapy in inflammatory bowel disease by comparing existing research studies and trials. We analyzed RCTs published in pubMed to assess the efficacy and safety of probiotics in patients with IBD in preventing frequent disease flare-ups and reducing the cost of care. Research Methods: We did a comparative analysis of available RCTs using a pubMed search and included studies that researched the addition of probiotic strains in patients with IBD (ulcerative colitis and Crohn’s disease). After reviewing the inclusion and exclusion criteria, the trials selected for analysis were reviewed by two independent reviewers. Results: We analyzed 21 RCTs, and 16 RCTs (76.2%) showed that probiotics are an effective therapy for IBD, inducing remission and reducing flare-up rates in patients on a standard treatment regimen. Conclusion: probiotics given in combination with standard therapy in IBD are effective in decreasing disease activity rates and reducing remission rates. No significant adverse reactions to probiotics were noticed.

关键词： probiotics Inflammatory Bowel Disease Crohn’s Disease Ulcerative Colitis Remission Rates