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Reduced Activation Energy of Iron and Copper Ion Doped Mullite which Can Be Used as a Substrate in Electronic Industry

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Journal of Surface Engineered Materials and Advanced Technology 2013年第3期3卷 11-17页

作者： Debasis Roy kumaresh haldar Biplab Kumar Paul Alakananda Bhattacharya Sukhen Das Papiya Nandy Physics Department Jadavpur University Kolkata India.

The crystallized mullite composite has been synthesized via sol-gel technique in the presence of transition metal ions such as iron and copper. The electrical resistivity and activation energy of the composites have been measured and their variation with concentration of the metal ion has been investigated. The resistivity of doped mullite decreases rapidly in the shorter temperature range and sharply in the higher temperature range. The decreasing resistivity is due to the 3d orbital electrons and the concentration of metal ions present. X-ray analysis confirms the presence of metal ions in mullite, which entered in the octahedral site. The Fe2+ and Cu2+ ions will substitute Al3+ ion in the octahedral site of mullite structure and most probably will be responsible for reducing the resistivity as well as the activation energy. Transition metal ion doped mullite-based ceramic can be considered as promising material as a substrate in the electronic industry, because of its reasonable atom density, its low activation characteristics, low thermal expansion coefficient and high mechanical strength. The present material we have developed has an activation energy of resistivity/band gap energy, Eg, 1.11 eV at 0.04 M concentration for Cu2+ ion.

关键词： Nanostructures Sol-Gel Growth X-Ray Diffraction Scanning Electron Microscopy (SEM) Electrical Conductivity

Dengue hemorrhagic fever with rectus sheath hematoma:A case report

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Asian Pacific Journal of Tropical Medicine 2024年第3期17卷 136-138页

作者： Boudhayan Bhattacharjee Hardik Patel Rucha Karad Vasireddy Teja Agnibho Mondal Soumendra Nath haldar Bibhuti Saha Department of Infectious Diseases and Advanced Microbiology School of Tropical MedicineKolkataIndia

Rationale:Acute pain is a medical emergency that requires prompt abdominal evaluation and ***,a mosquito-borne arboviral infection,can lead to complications such as acute abdominal *** concerns:A 72-year-old hypertensive female presented with high-grade intermittent fever with chills and rigors for four *** was diagnosed with dengue fever(NS1Ag-reactive)the day before admission.A contrast-enhanced computed tomography of the abdomen showed a hematoma along the rectus sheath which was managed conservatively as per surgical ***:Dengue hemorrhagic fever with rectus sheath ***:Blood transfusion and fluid ***:Ten days after discharge,the patient reproted no pain in the right iliac fossa and the size of the hematoma was significantly ***:Although it is rarely seen as a cause of acute abdomen,complaints of adnominal pain should never be ignored in critical or convalescent phase of dengue *** investigations should be promptly conducted as hematoma is often difficult to be diagnosed *** in diagnosis of rectus sheath hematoma can be fatal.

关键词： Dengue fever Rectus sheath hematoma Surgical emergency Acute appendicitis

Dynamicity of Land Use/Land Cover(LULC):An analysis from peri-urban and rural neighbourhoods of Durgapur Municipal Corporation(DMC)in India

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Regional Sustainability 2023年第2期4卷 150-172页

作者： Subrata haldar Somnath MANDAL Subhasis BHATTACHARYA Suman PAUL Department of Geography Sidho-Kanho-Birsha UniversityPuruliaWest Bengal723104India Department of Economics Sidho-Kanho-Birsha UniversityPuruliaWest Bengal723104India

The availability of better economic possibilities and well-connected transportation networks has attracted people to migrate to peri-urban and rural neighbourhoods,changing the landscape of regions outside the city and fostering the growth of physical *** multi-temporal satellite images,the dynamics of Land Use/Land Cover(LULC)changes,the impact of urban growth on LULC changes,and regional environmental implications were investigated in the peri-urban and rural neighbourhoods of Durgapur Municipal Corporation in *** study used different case studies to highlight the study area’s heterogeneity,as the phenomenon of change is not *** TM and OLI-TIRS satellite images in 1991,2001,2011,and 2021 were used to analyse the changes in LULC *** used the relative deviation(RD),annual change intensity(ACI),uniform intensity(UI)to show the dynamicity of LULC types(agriculture land;built-up land;fallow land;vegetated land;mining area;and water bodies)during *** study also applied the Decision-Making Trial and Evaluation Laboratory(DEMATEL)to measure environmental sensitivity zones and find out the causes of LULC *** to LULC statistics,agriculture land,built-up land,and mining area increased by 51.7,95.46,and 24.79 km^(2),respectively,from 1991 to *** results also suggested that built-up land and mining area had the greatest land surface temperature(LST),whereas water bodies and vegetated land showed the lowest ***,this study looked at the relationships among LST,spectral indices(Normalized Differenced Built-up Index(NDBI),Normalized Difference Vegetation Index(NDVI),and Normalized Difference Water Index(NDWI)),and environmental *** results showed that all of the spectral indices have the strongest association with LST,indicating that built-up land had a far stronger influence on the *** spectral indices indicated that the decreasing trends of vegetated land and water bodies were 4.26

关键词： Land Use/Land Cover(LULC) Peri-urban and rural neighbourhoods Normalized Differenced Built-up Index(NDBI) Normalized Difference Vegetation Index(NDVI) Normalized Difference Water Index(NDWI) Land surface temperature(LST) Environmental sensitivity

Selective inhibition of resistant bacterial pathogens using a β-lactamase-activatable antimicrobial peptide with significantly reduced cytotoxicity

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Chinese Chemical Letters 2023年第5期34卷 241-245页

作者： Weipan Xu Zheng Ma Geetika Dhanda Jayanta haldar Hexin Xie State Key Laboratory of Bioreactor Engineering Shanghai Key Laboratory of New Drug DesignFrontiers Science Center for Materiobiology and Dynamic ChemistryShanghai Frontier Science Research Base of Optogenetic Techniques for Cell MetabolismSchool of PharmacyEast China University of Science and TechnologyShanghai 200237China Antimicrobial Research Laboratory New Chemistry UnitJawaharlal Nehru Centre for Advanced Scientific Research(JNCASR)JakkurBengaluru 560064India School of Advanced Materials Jawaharlal Nehru Centre for Advanced Scientific Research(JNCASR)JakkurBengaluru 560064India

The expression ofβ-lactamase,particularly metallo-β-lactamase(MBL)in bacteria has caused significant resistance to clinically importantβ-lactam antibiotics,including life-saving *** peptides(AMPs)have emerged as promising therapeutic agents to combat antibiotic ***,the cytotoxic AMPs has been one of the major concerns for their applications in clinical ***,we report a novel cephalosporin-caged AMP,which shows significantly reduced cytotoxicity,hemolytic activity,and antibacterial activity but turns highly active against bacteria upon specific hydrolysis by the antimicrobial resistance-causativeβ-*** investigations demonstrate thisβ-lactamaseactivatable AMP selectively inactivates resistant bacterial pathogens over susceptible *** strategy should be applicable to other AMPs as a potential solution for the treatment of infectious diseases caused byβ-lactamase-expressing pathogenic bacteria.

关键词： Antibiotic resistance β-Lactamase Antimicrobial peptide Cytotoxicity

Properties of Particle Trajectory Around a Weakly Magnetized Black Hole

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Communications in Theoretical Physics 2018年第11期69卷 593-601页

作者： Amritendu haldar Ritabrata Biswas Department of Physics Sripat Singh College Department of Mathematics University of Burdwan Golapbag Academic Complex

In this paper, we consider charged accelerating AdS black holes with nonlinear electromagnetic source. The metric chosen by us is of a regular black hole, which shows regular nature at poles and a conical effect, which corresponds to a cosmic string. In such a space time construction of the Lagrangian for a charged particle is done. Cyclic coordinates as well as the corresponding symmetry generators, i.e., the Killing vectors are found. Conservation laws corresponding to the symmetries are counted. Euler-Lagrange equations are found. The orbit is mainly taken to be a circular one and effective potential is found. The minimum velocity obtained by a particle to escape from innermost stable circular orbit is found. The value of this escape velocity is plotted with respect to the radius of the event horizon of the central black hole for different parametric values. The nature of the escape velocity is studied when the central object is working with gravitational force and charge simultaneously. Effective potential and effective force are also plotted. The range of radius of event horizon for which the effective force turns to be positive is found out. A pathway of future studies of accretion disc around such black holes is made.

关键词： Euler-Lagrange equation cyclic co-ordinate escape velocity center of mass energy and effective force

Spatio-temporal behaviours of tropical cyclones over the bay of Bengal Basin in last five decades

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Tropical Cyclone Research and Review 2022年第1期11卷 1-15页

作者： Manas Mondal Anupam Biswas Subrata haldar Somnath Mandal Subhasis Bhattacharya Suman Paul Dept.of Geography Sidho Kanho Birsha UniversityPuruliaW.B India Dept.of Economics Sidho Kanho Birsha UniversityPuruliaW.B India

Present research is an endeavour to scrutinise the spatio-temporal climatic characteristics of tropical cyclones(TCs)bustle in the Bay of Bengal basin,found in RSMC-IMD data all through 1971–2020.A large number of TCs,i.e.121 with a decadal average of 35.2 TCs has been examined for the last 50 years where depression(D)and deep depression(DD)have not been taken into account as these are less violent in *** the study periods,inter-annual and inter-decadal variation in cyclogenesis,landfall,length,speed,track shape and sinuosity,energy metrics and damage profile have been *** study is clearly showing TCs took the northward track during the pre-monsoon season and made their landfall across the coasts of Bangladesh and Myanmar,while post-monsoon TCs made their landfall directly on the coasts of Orissa and West *** the post-monsoon phase,VF,ACE and PDI are significantly higher than in the monsoon season in the case of TCs and higher in the pre-monsoon season than in the monsoon season in the case of TCs comparing the energy metrics in different *** activity is comparatively pronounced during La Niña and El Niño regimes respectively and the genesis position in the BoB is moves to the east(west)of 87°*** the cold regime,the number of extreme TC above the VSCS category,increased *** is believed that the research findings will help stakeholders of the nation to take accurate strides to combat such violent events with persistent intensification.

关键词： Tropical cyclones RSMC-IMD Cyclogenesis Energy metrics La Niña and El Niño

Factorial Correlators and Oscillatory Multiplicity Moments at the CERN SPS Energy for Ring-Like and Jet-Like Events

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Chinese Physics Letters 2011年第1期28卷 62-65页

作者： Prabir Kumar haldar Sanjib Kumar Manna Dinhata College Department of Physics Dinhata Coochbehar West Bengal India

We present an analysis of ring-like and jet-like events in terms of factorial correlations and oscillatory multiplicity moments of 32S Ag/Br interactions at 200 A OeV. The investigation reveals that the correlated moments increase with decrease in bin-bin separation D, following the power law, which suggests the presence of an intermittent nature of self-similar dynamical fluctuations pattern for ring-like and jet-like events. The analysis further shows that the strength of the non-statistical fluctuations is larger for jet-like events than those of ring-like events and total events. However, ring-like and jet-like events are not to be consistent with the total events of the c~ model of intermittency. To go beyond the lower order correlation, the oscillatory multiplicity moments are used to study the higher order correlation. The ratios Hq （cumulant over factorial moments, Kq/Fq） are determined for ring-like, jet-like and the total events. The presence of few-particle short range correlation is established. It is extremely interesting to observe that the oscillations of ring-like events are different from the jet-like events and the total events. However, in almost all the cases, the simulated interactions fail to replicate the experimental results.

关键词： Nuclear physics

Influence of dynamic soil-pile raft-structure interaction:an experimental approach

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Earthquake Engineering and Engineering Vibration 2015年第4期14卷 625-645页

作者： Rajib Saha Sumanta haldar Sekhar Chandra Dutta Civil Engineering Department National Institute of Technology Agartala School of Infrastructure Indian Institute of Technolgy Bhubaneswar Department of Civil Engineering Indian School of Mines

Traditionally seismic design of structures supported on piled raft foundation is performed by considering fixed base conditions, while the pile head is also considered to be fixed for the design of the pile foundation. Major drawback of this assumption is that it cannot capture soil-foundation-structure interaction due to flexibility of soil or the inertial interaction involving heavy foundation masses. Previous studies on this subject addressed mainly the intricacy in modelling of dynamic soil structure interaction (DSSI) but not the implication of such interaction on the distribution of forces at various elements of the pile foundation and supported structure. A recent numerical study by the authors showed significant change in response at different elements of the piled raft supported structure when DSSI effects are considered. The present study is a limited attempt in this direction, and it examines such observations through shake table tests. The effect of DSSI is examined by comparing dynamic responses from fixed base scaled down model structures and the overall systems. This study indicates the possibility of significant underestimation in design forces for both the column and pile if designed under fixed base assumption. Such underestimation in the design forces may have serious implication in the design of a foundation or structural element.

关键词： soil-foundation-structure interaction piled raft foundation base shear pile head shear model test

Effects of thermal radiation on MHD viscous fluid flow and heat transfer over nonlinear shrinking porous sheet

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Applied Mathematics and Mechanics(English Edition) 2011年第6期32卷 677-688页

作者： G.C.SHIT R.haldar Department of Mathematics Jadavpur University

This paper investigates the effects of thermal radiation on the magnetohy- drodynamic （MHD） flow and heat transfer over a nonlinear shrinking porous sheet. The surface velocity of the shrinking sheet and the transverse magnetic field are assumed to vary as a power function of the distance from the origin. The temperature dependent viscosity and the thermal conductivity are also assumed to vary as an inverse function and a linear function of the temperature, respectively. A generalized similarity transfor- mation is used to reduce the governing partial differential equations to their nonlinear coupled ordinary differential equations, and is solved numerically by using a finite difference scheme. The numerical results concern with the velocity and temperature profiles as well as the local skin-friction coefficient and the rate of the heat transfer at the porous sheet for different values of several physical parameters of interest.

关键词： thermal radiation shrinking sheet variable viscosity variable thermalconductivity