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International Journal of minerals,metallurgy and materials 2015年第4期22卷 389-394页

作者： S.Deepak Kumar A.mandal m.chakraborty School of mechanical Sciences Indian Institute of Technology Bhubaneswar School of minerals Metallurgical and Materials Engineering Indian Institute of Technology Bhubaneswar

The key factor in semi-solid metal processing is the solid fraction at the forming temperature because it affects the microstructure and mechanical properties of the thixoformed components. Though an enormous amount of data exists on the solid fraction-temperature re- lationship in A356 alloy, information regarding the solid fraction evolution characteristics of A356-TiB2 composites is scarce. The present article establishes the temperature-solid fraction correlation in A356 alloy and A356-xTiB2 （x = 2.5wt% and 5wt%） composites using dif- ferential thermal analysis （DTA）. The DTA results indicate that the solidification characteristics of the composites exhibited a variation of 2℃ and 3℃ in liquidus temperatures and a variation of 3℃ and 5℃ in solidus temperatures with respect to the base alloy. moreover, the eutectic growth temperature and the solid fraction（fs） vs. temperature characteristics of the composites were found to be higher than those of the base alloy. The investigation revealed that in-situ formed TiB2 particles in the molten metal introduced more nucleation sites and reduced undercooling.

关键词： particle reinforced composites aluminum alloys titanium boride casting solid fraction differential thermal analysis

Influence of Discharge Voltage on Charged Particles in a multi-Dipole Device in the Presence of an Ion Collecting Surface

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Chinese Physics Letters 2013年第1期30卷 122-126页

作者： m.K.mishra A.Phukan m.chakraborty Department of Physics Baosi Banikanta Kakati CollegeNagaonBarpetaAssam-781311India Department of Physics Madhabdev CollegeNarayanpurLakhimpurAssam-784164India Centre of Plasma Physics-Institute for Plasma Research TepesiaSonapurAssam-782402India

The influence of discharge voltage on ion collecting surfaces in the form of a metal plate and a mesh grid is investigated in a multi-dipole *** the experiment,a solid metal plate and a mesh grid are placed alternately at one end of the multi-dipole *** is seen that except for high negative bias,the ion space charge layer in front of the grid gets depleted with the increase in discharge voltage whereas it gets thickened in front of the *** is also observed that the electron loss at the cusp(anode current)changes accordingly in both the *** increase in discharge voltage can enhance the Bohm speed of ions towards the ion collecting ***,the negative potential applied to the ion collecting surfaces lowers the bulk plasma potential,which in turn affects the anode current.

关键词： dipole anode thick

Integrating QoS management in TLmm:Three Level mobility model for Next Generation Wireless IP-Based Networks

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China Communications 2008年第3期5卷 125-139页

作者： m.chakraborty I.S.misra A.mukherjee Department of Information Technology Institute of Engineering & Management Department of Electronics and Telecommunication Engineering Jadavpur University IBm Global Services

In this paper we have designed an implemented an integrated framework of QoS for Three Level mobility model(TLmm),which has been recently proved to be the optimal mobility management solution for next generation wireless IP-based *** QoS solution uses a combination of IntServ and DiffServ models incorporated in TLmm *** paper also proposes an effi cient dynamic handover policy that takes care of false *** and analytical results have shown that this infrastructure guarantees eff icient QoS handling and scalability among end *** provide a comparative understanding of the QoS mechanism and signaling load of TLmm we have used TelemIP(without QoS support) and mIP as alternative mobility management protocols.

关键词： Qos NGN wireless IP network

Influence of in-flight particle state diagnostics on properties of plasma sprayed YSZ-CeO_(2) nanocomposite coatings

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International Journal of Smart and Nano materials 2014年第3期5卷 207-216页

作者： S.mantry B.B.Jha A.mandal D.K.mishra B.K.mishra m.chakraborty CSIR-Institute of minerals&materials Technology Bhubaneswar 751013OdishaIndia School of minerals Metallurgical and Materials EngineeringIndian Institute of Technology BhubaneswarBhubaneswar 751007OdishaIndia Department of Physics Institute of Technical Education and ResearchSiksha‘O’Anusandhan UniversityKhandagiri SquareBhubaneswar 751030OdishaIndia Department of Physics College of ScienceEngineering and TechnologyUniversity of South AfricaJohannesburgSouth Africa

This article describes the influence of controlling in-flight hot particle characteristics on properties of plasma sprayed nanostructured yttria stabilized zirconia(YSZ)*** article depicts dependence of adhesion strength of as-sprayed nanostructured YSZ coatings on particle temperature,velocity and size of the splat prior to impact on the metallic *** temperature measurement is based on two-color pyrometry and particle velocities are measured from the length of the particle traces during known exposure *** microstructure and adhesion strength of as-sprayed nano-YSZ coatings were *** emission scanning electron microscopy results revealed that morphology of coating exhibits bimodal microstructure consisting of nano-zones reinforced in the matrix of fully melted *** coating adhesion strength is noticed to be greatly affected by the melting state of *** adhesion strength of 42.39 mPa has been experimentally found out by selecting optimum levels of particle temperature and *** enhanced bond strength of nano-YSZ coating may be attributed to higher interfacial toughness due to cracks being interrupted by adherent nano-zones.

关键词： CeYSZ nano-zones spray diagnostics adhesion plasma spraying

Balancing machine learning and artificial intelligence in soil science with human perspective and experience

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Pedosphere 2024年第1期34卷 9-12页

作者： David C.WEINDORF Somsubhra chakraborty Department of Earth and Atmospheric Science Central Michigan Universityount Pleasant M148859USA Agricultural and Food Engineering Department Indian Institute of TechnologyKharagpur 721302India

machine learning and artificial intelligence continue to evolve at a rapid pace, with many potential applications related to soil science. Even so, human experience and perception play an invaluable role in characterizing soil properties, especially qualitative properties that may elude sensing/computer-based modeling approaches. The elegant solution to this conundrum relies on the synthesis of computer-aided predictive modeling with human insight and *** global population surpasses 8 billion, the importance of optimized agronomic production to feed a hungry world has never been more important.

关键词： soil elude qualitative

An Autopsy and Histopathology-based Study to Ascertain the Cause of Death of Brought Dead Cases

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Journal of Forensic Science and medicine 2024年第1期10卷 28-33页

作者： Chandan Bandyopadhyay Prabir Chandra Paul Prabhas Chandra chakraborty Department of Forensic and State medicine Medical CollegeKolkataWest BengalIndia Department of Pathology Jagannath Gupta Institute of Medical Science and HospitalKolkataWest BengalIndia Department of Forensic medicine and Toxicology NRS Medical College and HospitalKolkataand M.G.M Medical College and L S.K HospitalKishanganjBiharIndia

Background and Objectives:The cases of apparent natural deaths are encountered in the hospital casualties who are noted dead at the time of the first medical attention and as such are labeled as“Brought Dead.”These include the cases of sudden death,unexplained death,and unattended *** cause of such deaths is reported in the literature to emanate principally from the cardiovascular system,though there are some documented geographical,racial,and other *** the present study,we endeavored to detect the cause of such natural deaths in terms of the disease and the organ system involved,in the deceased individuals of the contemporary Bengali population,with cases due to obvious unnatural causes being *** and methods:An observational,cross-sectional study with 105(n=105,male:89,female:16)study subjects of age group of 20-80 years,selected by systemic random sampling,from the brought dead subjects coming to the mortuary of the NRS medical College and Hospital for medicolegal autopsy from April 2011 to march 2012,excluding cases having a history of the obvious unnatural *** system-wise gross examination was done,followed by tissue sampling for histopathological *** case-wise findings were tabulated and analyzed for descriptive statistics using SPSS ***:In the present study,89 cases were male(84.8%)and 16 cases were female(15.2%),which reflects a male:female ratio of 5.56:*** dead bodies are mostly recovered from the footpaths(47 cases,44%).Sixty-four(61%)cases are of known *** 54 cases out of 105(51.4%),morbid pathology is detected in the respiratory system(RS),lobar pneumonia,and cavitary pulmonary tuberculosis being the most frequent disease entity,in both ***-one years-sixty-five years is found to be the most commonly affected age group,in both *** and Conclusions:The present study shows that the most common organ system involved in brought dead cases is the RS,which is s

关键词： Autopsy brought dead cause of death histopathology

Heavy metal contamination and health risk assessment of road dust from landfills in Dhaka-Narayanganj, Bangladesh

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Emerging Contaminants 2024年第1期10卷 117-125页

作者： mrittika chakraborty md masudur Rahman Rahat Tasrina Rabia Choudhury Refayat Nigar Guorui Liu Ahsan Habib Department of Chemistry University of DhakaDhaka1000Bangladesh Analytical Chemistry Laboratory Chemistry DivisionAtomic Energy Centre Dhaka Bangladesh Atomic Energy CommissionDhaka1000Bangladesh State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental ScienecsChinese Academy of SciencesBeijing100085China

In the recent years,air pollution has become an alarming issue for human health in many rapidly growing megacities including Dhaka and ***,pollution status and health risk have been assessed by the road dusts collected from landfills in Dhaka and Narayanganj through determination of heavy metals including Pb,Cd,Cr,As,Cu,Ni,Zn and mn using atomic absorption *** collected dust samples have been grouped into three sizes,for example,150,75 andm,to assess the degree of heavy metal accumulation in the dust *** dust particles were accumulated with high concentrations of Pb and As at matuail landfills,whereas Cd,Cr,Zn,and mn concentrations were highest at Narayanganj *** finer particles,for example 75μm,accumulated substantial concentrations of heavy *** index and pollution load index(PLI)results revealed that all of the sites were deteriorated by Pb,Cd,Cu,Zn and *** results exhibited that the quality of the matuail landfill area was severely *** terms of non-carcinogenic health risk,the values of hazard quotient for ingestion were greater than those for inhalation and dermal *** adult groups,hazard index values for the matuail landfills and medical waste incineration sites were greater than 1,while for the children groups,the values for the same areas,including the Narayanganj landfills,were also larger than *** values were at least one order of magnitude higher for the children groups than for the adult *** the results,it would be reasonable to draw the conclusion that non-carcinogenic health risks for children may be more prevalent in the relevant areas.

关键词： Road dusts Heavy metals Landfills Bangladesh Degree of accumulation Health risk assessment

Influence of cerium ions on structure-dependent magnetic properties of Ba-Sr m-type hexaferrite nanocrystals

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Journal of Rare Earths 2024年第2期42卷 364-372,I0005页

作者： Ram A.Pawar Sunil m.Patange P.m.Dighe Sher Singh meena Abdullah GAl-Sehemi mehboobali Pannipara Santosh S.Jadhav Department of Physics ArtsCommerce and Science CollegeAhmednagar413711MaharashtraIndia Department of Physics Shri Krishna MahavidyalayaGunjotiDistOsmanabad413606MaharashtraIndia Padmashri Vikhe Patil College of Arts Science and CommercePravaranagarA/P.Loni(Kd)Tal.RahataDistAhmednagar413713MaharashtraIndia Solid State Physics Division Bhabha Atomic Research CentreMumbai400085MaharashtraIndia Department of Chemistry King Khalid UniversityAbha61413Saudi Arabia Department of Physics D.S.M's ArtsCommerce and Science CollegeJintur431509MaharashtraIndia

The present study is a systematic effort to investigate the structure-sensitive magnetic parameters of Ce^(3+) substituted Ba-Sr hexaferrite nanocrystals chemically formulated as Ba_(0.5)Sr_(0.5)Ce_(x)Fe_(12-x)O_(19) where x=0.0-0.2 with Δx=*** hexaferrite powders were prepared using the sol-gel self-ignition route and structurally characterized by means of powder X-ray diffraction and Fourier transform infrared *** creation of the m-type hexaferrite phase within the synthesized samples was revealed from the Rietveld refinement of the X-ray *** occurrence of a secondary phase of CeO_(2) was revealed within the hexaferrites for the substitution,x> *** refined X-ray diffraction data were utilized to compute the lattice parameters,X-ray density,and lattice parameter *** crystal structure plotted from the refined XRD data reveals the occupancy of the ions at different lattice *** XPS data of the hexaferrite were analyzed to confirm the oxidation states of the constituent *** nanocrystalline nature of the hexaferrites was revealed from the crystallite sizes calculated using Scherer's *** analysis of FTIR spectra confirms that only a fraction of Ce^(3+)accommodated in the lattice and the remaining Ce content reside in the form of the CeO_(2) *** morphology of the hexaferrites was analyzed from the FESEm profiles of the ferrite *** magnetic behavior study was performed by analyzing the Curie temperature,hysteresis loops,and hyperfine interactions by means of susceptibility,V.S.m,and mossbauer spectroscopy,*** hexaferrites with increasing coercivity,decreasing saturation magnetization,and decreasing Curie temperature are reported in the *** substituted Ce^(3+)ions inhibit the grain growth and create lattice imperfections giving rise to hexaferrites with tuned magnetic parameters suitable for different applications.

关键词： Ba-Sr hexaferrite Ce^(3+)substitution XPS Saturation magnetization Coercivity m?ssbauer spectroscopy

Frequency-dependent viscoelasticity effects on the wave attenuation performance of multi-layered periodic foundations

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Applied mathematics and mechanics(English Edition) 2024年第3期45卷 407-424页

作者： m.SAFI m.VAKILIFARD m.J.mAHmOODI Faculty of Civil Water&Environmental EngineeringShahid Beheshti UniversityTehran ***Iran Faculty of mechanical and Energy Engineering Shahid Beheshti UniversityTehran ***Iran

In this paper,layered periodic foundations(LPFs)are numerically examined for their responses to longitudinal and transverse modes in the time and frequency *** different unit-cells,i.e.,2-layer,4-layer,and 6-layer unit-cells,comprising concrete/rubber,concrete/rubber/steel/rubber,and concrete/rubber/steel/rubber/lead/rubber materials,respectively,are taken into ***,the viscoelasticity behavior of the rubber is modeled with two factors,i.e.,a frequency-independent(FI)loss factor and a linear frequency-dependent(FD)loss *** the extraction of the complex dispersion curves and the identification of the band gaps(BGs),the simulations of wave transmission in the time and frequency domains are performed using the COmSOL *** parametric studies evaluate the effects of the rubber viscoelasticity models on the dispersion curves and the wave transmission for the longitudinal and transverse *** results show that considering the rubber viscoelasticity enhances the wave attenuation ***,the transverse-mode damping is more sensitive to the viscoelasticity model than its longitudinal *** 6-layer unit-cell LPF exhibits the lowest BG,ranging from 4.8 Hz to 6.5 Hz.

关键词： layered metamaterial periodic foundation complex dispersion curve wave transmission diagram

Engineering of efficient visible light photocatalysts:Ti_(1-x+y)Cu_(x)La_(y)O_(2)(x=0.03;y=0,0.005,0.01) compositions

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Journal of Rare Earths 2024年第3期42卷 497-505,I0003页

作者： S.m.Yakout A.m.Youssef Inorganic Chemistry Department National Research Centre(NRC)El Buhouth StDokkiCairo12622Egypt

In dye-photocatalysis, widening the wavelengths absorption range of catalysts as well as aborting the recombination of the photoexcited charge carriers(electrons-holes pairs) are of paramount *** the current study, we report the photocatalytic characteristics of four compositions composed of TiO_(2),Ti_(0.97)Cu_(0.03)O_(2), Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders for two harmful dyes(Congo red and methylene blue). The X-ray diffraction technique verified the configuration of mixed anatase and rutile phases in pure TiO_(2)and Ti_(0.97)Cu_(0.03)O_(2)powders while Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders possess anatase phase only. The changes of the band gap structure and dimensions of the unit cell volume of TiO_(2)confirm the substitution of Ti^(4+)sites by Cu^(2+)and La^(3+)ions. Remarkable widening of wavelengths absorption with formation of long absorption tails were found in TiO_(2)(3.13 e V) through insertion of La^(3+)plus Cu^(2+)ions. Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)samples exhibit a visible light band gap of 2.3 and 2.7 e V, respectively. Based on SEm images, incorporation of Cu^(2+)and La^(3+)ions influences the surface morphology of TiO_(2). The resulting Ti_(0.97)Cu_(0.03)O_(2), Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders present enhanced photocatalytic activity towards Congo red dye degradation compared to pure one under natural solar spectrum. The best Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)catalyst exhibits superior photocatalytic activity of 96% for 10 ppm CR dye in 20 min as well as above average photocatalytic efficiency of 63% for 30 ppm CR dye in 120 min. As well, it showed acceptable photodegradation activity of 52% for 30 ppm mB solution in 140 min of sunlight irradiation. The heightened photodegradation efficiency of Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)catalyst can be clarified in terms of higher ch

关键词： Semiconductor TiO_(2) Rare earths Congo red methylene blue Solar spectrum Photodegradation