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Additive friction stir deposition of AZ31B magnesium alloy

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Journal of Magnesium and Alloys 2022年第9期10卷 2404-2420页

作者： Sameehan S.Joshi Shreyash M.Patil sangram mazumder Shashank Sharma Daniel A.Riley Shelden Dowden Rajarshi Banerjee Narendra B.Dahotre Department of Materials Science and Engineering University of North Texas3940 N Elm StDentonTX 76207USA Center for Agile and Adaptive Additive Manufacturing University of North Texas3940 N Elm StDentonTX 76207USA

The current work explored additive friction stir deposition of AZ31B magnesium alloy with the aid of MELD?***31B magnesium bar stock was fed through a hollow friction stir tool rotating at constant velocity of 400 rpm and translating at linear velocity varied from 4.2 to 6.3 mm/s.A single wall consisting of five layers with each layer of 140×40×1 mm^(3)dimensions was deposited under each processing ***,phase,and crystallographic texture evolutions as a function of additive friction stir deposition parameters were studied with the aid of scanning electron microscopy including electron back scatter diffraction and X-ray *** feed material and additively produced samples consisted of theα-Mg *** additively produced samples exhibited a refined grain structure compared to the feed *** feed material appeared to have a weak basal texture,while the additively produced samples experienced a strengthening of this basal *** additively produced samples showed a marginally higher hardness compared to the feed *** current work provided a pathway for solid state additive manufacturing of Mg suitable for structural applications such as automotive components and consumable biomedical implants.

关键词： Additive friction stir deposition Magnesium alloys Additive manufacturing Thermomechanical processing Materials processing Solid state additive manufacturing

Exploring the combination of biochar‐amended soil and automated irrigation technology for water regulation and preservation in green infrastructure

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Deep Underground Science and Engineering 2024年第1期3卷 39-52页

作者： Honghu Zhu Yuanxu Huang Haihong Song Jian Chen Songlei Han Tanwee mazumder Ankit Garg School of Earth Sciences and Engineering Nanjing UniversityNanjingChina Department of Civil and Smart Engineering Construction Guangdong Engineering Center for Structure Safety and Health MonitoringShantou UniversityShantouChina Shanghai Municipal Engineering Design Co. LtdShanghaiChina Indian Institute of Technology Madras ChennaiIndia

Biochar is a carbon sink material with the potential to improve water retention in various ***,for the long‐term maintenance of green infrastructure,there is an additional need to regulate the water contents in the covers to maintain vegetation growth in semiarid *** this study,biochar‐amended soil was combined with subsurface drip irrigation,and the water preservation characteristics of this treatment were investigated through a series of one‐dimensional soil column *** ascertain the best treatment method specific to semiarid climatic conditions,the test soil was amended with 0%,1%,3%,and 5%*** irrigation devices equipped with soil moisture sensors were used to control the subsurface water content with the aim of enhancing vegetation *** soil column test lasted 150 h,during which the volumetric water contents and soil suction data were *** experimental results reveal that the soil specimen amended with 3%biochar is the most water‐saving regardless of the time *** with a higher biochar content(e.g.,5%)consumes a more significant amount of water due to the enhancement of the water‐holding *** on the experimental results,it can be concluded that the appropriate ratio can be determined within 1%–3%,which can reduce not only the amount of irrigated/used water but also the time *** technology can be explored for water content regulation in green infrastructure and the development of barriers for protecting the environment around deep underground waste containment.

关键词： biochar drip irrigation underground water preservation water regulation

Upper gastrointestinal bleeding in Bangladeshi children:Analysis of 100 cases

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World Journal of Gastrointestinal Endoscopy 2024年第1期16卷 44-50页

作者： Md Wahiduzzaman mazumder Md Benzamin Department of Pediatric Gastroenterology and Nutrition Bangabandhu Sheikh Mujib Medical UniversityDhaka 1000Bangladesh Department of Pediatric Gastroenterology and Nutrition Sylhet M A G Osmani Medical College HospitalSylhet 3100Bangladesh

BACKGROUND Upper gastrointestinal bleeding(UGIB)is defined as bleeding that occurs proximal to the ligament of Treitz and can sometimes lead to potentially serious and life-threatening clinical situations in ***,the cause of UGIB differs significantly depending on the geographic location,patient population and presence of comorbid *** To observe endoscopic findings of UGIB in children at a tertiary care center of *** This retrospective study was carried out in the department of Pediatric Gastroenterology and Nutrition of Bangabandhu Shiekh Mujib Medical University,a tertiary care hospital of Bangladesh,between January 2017 and January *** collected from hospital records of 100 children who were 16 years of age or younger,came with hematemesis,melena or both hematemesis and *** patients underwent upper gastrointestinal endoscopy(Olympus CV 1000 upper gastrointestinal video endoscope)after initial *** investigations to diagnose portal hypertension and chronic liver disease with underlying causes for management purposes were also *** A total of 100 patients were *** was common in the age group 5-10 years(42%),followed by above 10 years(37%).Hematemesis was the most common presenting symptom(75%)followed by both hematemesis and melena(25%).UGIB from ruptured esophageal varices was the most common cause(65%)on UGI endoscopy followed by gastric erosion(5%)and prolapsed gastropathy(2%).We observed that 23%of children were normal after endoscopic *** Ruptured esophageal varices were the most common cause of UGIB in children in *** causes included gastric erosions and prolapsed gastropathy syndrome.

关键词： Bangladeshi Children Endoscopy Upper gastrointestinal bleeding Esophageal varices

Phytochemical Screening and Evaluation of Pharmacological Potential of Baliospermum solanifolium Leaf Extract

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Clinical Complementary Medicine and Pharmacology 2024年第1期4卷 69-75页

作者： Amit mazumder Rabindra Nath Acharyya Milton Kumar Kundu Pritam Kundu Md.Amirul Islam Md.Mustafizur Rahman Pharmacy Discipline Khulna UniversityKhulna-9208Bangladesh

Background:Baliospermum solanifolium is a traditional medicinal plant,locally known as“dantigaacha”from Eu-phorbiaceae family,and has been used in different diseases treatments likes helminthiasis,skin diseases,diabetes,snake-bite,and ***:Depending on the traditional uses of *** and the lack of scientific works,we aimed to conduct some pharmacological tests on its ***:Active constituents of *** were assessed by qualitative ***(2,2-diphenyl-1-picrylhydrazyl)was used for free radical scavenging *** change and mortality rate were used as indicators to assess the toxicity of *** antidiabetic potential was evaluated by oral glucose toler-ance test(OGTT)and alpha-glucosidase enzyme inhibitory *** antidiarrheal activity,castor oil-induced mice were *** test was carried out by disk diffusion assay and MIC ***,analgesic activity was done by acetic acid-induced writhing ***:*** contains alkaloids,carbohydrates,glycosides,flavonoids,tannis,phenolics *** toxicity test ensured the safety of the *** DPPH,the extract showed antioxidant activity with an IC50(con-centration needed to scavenge 50%DPPH)value of 61.65μg/*** phenolic,flavonoid and tannin contents were determined as 124 mg GAE/g,440 mg QE/g and 344 mg GAE/g dried extract,*** OGTT,the ex-tract reduced the blood glucose level *** the alpha-glucosidase inhibitory activity,the plant showed a concentration-dependent reduction of the enzyme at IC50 of 8.53 mg/*** the antidiarrheal test,*** inhibit defecation 30.69%and 53.41%at dose 250 mg/kg and 500 mg/kg,*** extract also showed antibacterial activity against four bacterial strains in the disk diffusion method and minimum inhibitory concen-tration(MIC)values were 62.5μg/mL,62.5μg/mL,125μg/mL and 62.5μg/mL against four bacterial strains,*** an

关键词： Baliospermum solanifolium Antioxidant Antidiabetic Antidiarrheal Antibacterial Analgesic

Properties of filaments in solar cycle 20-23 from McIntosh Archive

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Research in Astronomy and Astrophysics 2019年第6期19卷 43-50页

作者： Rakesh mazumder Center of Excellence in Space Sciences India Indian Institute of Science Education and Research Kolkata

A filament is a cool, dense structure suspended in the solar corona. The eruption of a filament is often associated with a coronal mass ejection(CME), which has an adverse effect on space weather. Hence,research on filaments has attracted much attention in the recent past. The tilt angle of active region(AR)magnetic bipoles is a crucial parameter in the context of the solar dynamo, which governs the conversion efficiency of the toroidal magnetic field to poloidal magnetic field. Filaments always form over polarity inversion lines(PILs), so the study of tilt angles for these filaments can provide valuable information about generation of a magnetic field in the Sun. We investigate the tilt angles of filaments and other properties using McIntosh Archive data. We fit a straight line to each filament to estimate its tilt angle. We examine the variation of mean tilt angle with time. The latitude distribution of positive tilt angle filaments and negative tilt angle filaments reveals that there is a dominance of positive tilt angle filaments in the southern hemisphere and negative tilt angle filaments dominate in the northern hemisphere. We study the variation of the mean tilt angle for low and high latitudes separately. Investigations of temporal variation with filament number indicate that total filament number and low latitude filament number vary cyclically, in phase with the solar cycle. There are fewer filaments at high latitudes and they also show a cyclic pattern in temporal variation. We also study the north-south asymmetry of filaments with different latitude criteria.

关键词： Sun filaments,prominences-Sun magnetic fields-Sun corona-Sun activity-(Sun:)sunspots

Prospects of a β-SiC based IMPATT oscillator for application in THz communication and growth of aβ-SiC p-n junction on a Ge modified Si〈100〉substrate to realize THz IMPATTs

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Journal of Semiconductors 2010年第12期31卷 20-27页

作者： Moumita Mukherjee Nilratan mazumder Centre of Millimeter-Wave Semiconductor Devices and Systems Centre of Advanced Study in Radiophysics and ElectronicsUniversity of CalcuttaGirish Vidyaratna LaneKolkata 700009West BengalIndia IERCEM Institute of Information Technology West Bengal University of TechnologyKolkata 700017India

The prospects ofa p＋nn＋ cubic silicon carbide （3C-SiC/fl-SiC） based IMPATT diode as a potential solidstate terahertz source is studied for the first time through a modified generalized simulation scheme. The simulation predicts that the device is capable of generating an RF power output of 63.0 W at 0.33 THz with an efficiency of 13%. The effects of parasitic series resistance on the device performance and exploitable RF power level are further simulated. The studies clearly establish the potential of 3C-SiC as a base semiconductor material for a high-power THz IMPATT device. Based on the simulation results, an attempt has been made to fabricate β-SiC based IMPATT devices in the THz region. Single crystalline, epitaxial 3C-SiC films are deposited on silicon （Si）（100） substrates by rapid thermal chemical vapour deposition （RTPCVD） at a temperature as low as 800 ℃ using a single precursor methylsilane, which contains Si and C atoms in the same molecule. No initial surface carbonization step is required in this method. A p-n junction with an n-type doping concentration of 4 × 10^24 m-3 （which is similar to the simulated design data） has been grown successfully and the characterization of the grown 3C-SiC film is reported in this paper. It is found that the inclusion of Ge improves the crystal quality and reduces the surface roughness.

关键词： cubic (β)-SiC single drift IMPATT diode parasitic resistance terahertz oscillation RTPCVD growth p-n junction formation

Memristor-based RRAM with applications

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Science China(Information Sciences) 2012年第6期55卷 1446-1460页

作者： mazumder Pinaki Department of Electrical Engineering and Computer Science University of MichiganAnn ArborMI 48109USA

Recently acclaimed the fourth fundamental circuit element,the memristor was theoretically pre-dicted by Leon Chua in 1971,although its single device electronic implementation eluded the attention of inte-grated circuit designers for the past three decades and was first reported in 2008 by the Hewlett-Packard (HP) Laboratory researchers while developing crossbar-based ultra high-density nonvolatile ***-based hybrid nanoscale CMOS technology is expected not only to impact the flash memory industries pro-foundly,but also to revolutionize digital and neuromorphic *** memristor exhibits a dynamical resistance state that depends on its excitation history and which can be exploited to build transistor-less non-volatile semiconductor memory (NVSM),commonly known as resistive RAM (RRAM).This paper addresses an implementation scheme for memristor-based resistive random access memory (MRRAM),a nano-scale binary memory that is compatible with modern computer *** structure is similar to that of static random ac-cess memory (SRAM),but with the memristor replacing the underlying RS *** improving the MRRAM,we propose a multilevel memory with greater data density,which stores multiple bit information in gray-scale form in a memory *** computer simulations and numerical analyses verify the effectiveness of the proposed scheme in storing ASCII characters and gray-scale images in binary format.

关键词： memristor RRAM binary information memory multilevel memory

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GAITing the GUT

Cellular & Molecular Immunology 2018年第12期15卷 1082-1084页

作者： Barsanjit mazumder Center for Gene Regulation in Health and Disease Department of BiologyGeology and Environmental SciencesCleveland State UniversityClevelandOHUSA

The gastrointestinal tract contains one of the most abundant populations of macrophages in the body.1 These cells play a critical role in the maintenance of gut homeostasis and defend the integrity of epithelial crypts and the mucosal *** disruption of gut homeostasis can cause sustained inflammation mediated by intestinal *** inflammation plays a key role in ulcerative colitis(UC)and other forms of inflammatory bowel disease(IBD),2–4 an improved understanding of how inflammation is regulated in the gut is essential for the development of effective therapies for such diseases.

关键词： inflammation homeostasis sustained

Turbulence,suspension and downstream fining over a sand-gravel mixture bed

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International Journal of Sediment Research 2013年第2期28卷 194-209页

作者： K.GHOSHAL Rahul mazumder C.CHAKRABORTY B.S.mazumder Department of Mathematics Indian Institute of TechnologyKharagpur 721302India Assist.Prof. MIT CambridgeUSA Post-Doctoral Assoc. Fluvial Mechanics Laboratory Physics and Earth Science DivisionIndian Statistical InstituteKolkata 700108India Prof.

Flume experiments were carried out to study the turbulence and its impact on suspension and segregation of grainsizes under unidirectional flow conditions over the sand-gravel mixture *** components of fluid velocity with fluctuations were measured vertically using 3-D Micro-acoustic Doppler velocimeter(ADV).The theoretical models for velocity and sediment suspension have been developed based on the concept of mixing length that includes the damping effect of turbulence due to sediment suspension in the flow over the sand-gravel mixture *** analysis of segregation of grain-sizes along downstream of the bed has been performed using the principle of unsupervised learning or clustering *** data analysis suggests that there is a progressive downstream fining of sediment sizes with selective depositions of gravels,sand-gravels and sand materials along the stream,which may be segmented into three regions such as,the upstream,the transitional and the downstream *** contribution is relevant to understand the direction of ancient rivers,the bed material character in the river form,sorting process and its role in controlling the sediment flux through landscape.

关键词： Sand-gravel mixture Flow velocity ADV Suspension concentration Size-sorting Clustering