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Diagenesis,facies and palaeocurrent analysis of Upper Rewa Sandstone around Sagar,Central India

Journal of Palaeogeography 2023年第4期12卷 546-563页

作者： Gaurav k.Singh ashish k.rai Arvind k.Singh Department of Applied Geology Dr.Harisingh Gour VishwavidyalayaSagar 470003Madhya PradeshIndia Geological Survey of India ShillongIndia

The stratigraphic surface represented by a major contact between the Archean Bundelkhand Granite and the extensive Proterozoic Vindhyan sediments is a regional basement cover *** crystalline—sedimentary interface reflects an intense weathering of continental crust during marine *** time-transgressive sand deposition events ***,Rewa and Bhander are mainly witnessed during the entire Vindhyan ***,the Upper Rewa Sandstone comprises one of these events in the Vindhyan *** progress has been made in interpreting these sandstones as a function of entirely marine process to a combination of tidal—fluvio—eolian *** the results have so far been attained on the basis of sedimentary facies,provenance,palaeocurrent analysis,and some of petrography.A distinct differentiation between marine and fluvial components of the Upper Rewa Sandstone still remains ***,we use diagenesis as a parameter for the first time along with facies and palaeocurrent analysis to acquire a clear comprehension of marine-and fluvial-dominated *** present study spans 27 square kilometer area covering 15 stratigraphic sections with a collection of 571directional data from the facies specific sedimentary structures,and 28 samples obtained for the thin section *** lower unit of the Upper Rewa Sandstone shows facies association typical of tidal environment,along with polymodal *** rocks are well sorted and dominantly lithified by authigenic *** development of a complex of syntaxial,passive pore fills,and grain replacive cements reflect normally pressured nature of the lower unit *** upper unit of the Upper Rewa Sandstone however,reveals a facies pattern resembling fluvial processes and unimodal palaeocurrent *** exhibit poor sorting,siliceous,and ferruginous matrix,and development of intense ***,pressure solution is a dominant mode of l

关键词： Palaeocurrent Diagenesis Facies Upper Rewa Sandstone Vindhyan Basin

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Recognition and quality mapping of traditional herbal drugs:way forward towards artificial intelligence

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Traditional Medicine Research 2025年第1期10卷 12-26页

作者： Sanyam Sharma Subh Naman ashish Baldi Faculty of Pharmacy Pacific Academy of Higher Education and Research UniversityUdaipur 313024India Pharma Innovation Lab Department of Pharmaceutical Sciences and TechnologyMaharaja Ranjit Singh Punjab Technical UniversityBathinda 151001India Faculty of Pharmaceutical Sciences The ICFAI UniversityBaddi 174103India.

The use of traditional herbal drugs derived from natural sources is on the rise due to their minimal side effects and numerous health ***,a major limitation is the lack of standardized knowledge for identifying and mapping the quality of these herbal *** article aims to provide practical insights into the application of artificial intelligence for quality-based commercialization of raw herbal *** focuses on feature extraction methods,image processing techniques,and the preparation of herbal images for compatibility with machine learning *** article discusses commonly used image processing tools such as normalization,slicing,cropping,and augmentation to prepare images for artificial intelligence-based *** also provides an overview of global herbal image databases and the models employed for herbal plant/drug *** will gain a comprehensive understanding of the potential application of various machine learning models,including artificial neural networks and convolutional neural *** article delves into suitable validation parameters like true positive rates,accuracy,precision,and more for the development of artificial intelligence-based identification and authentication techniques for herbal *** article offers valuable insights and a conclusive platform for the further exploration of artificial intelligence in the field of herbal drugs,paving the way for smarter identification and authentication methods.

关键词： artificial intelligence Ayurveda machine learning models herbal drugs image pre-processing medicinal plants

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The hemispheric asymmetry of solar activity during the last century and the solar dynamo

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Chinese Journal of Astronomy and Astrophysics 2009年第1期9卷 115-126页

作者： ashish Goel Arnab rai Choudhuri Department of Physics Indian Institute of Technology Department of Physics Indian Institute of Science

We believe the Babcock-Leighton process of poloidal field generation to be the main source of irregularity in the solar cycle. The random nature of this process may make the poloidal field in one hemisphere stronger than that in the other hemisphere at the end of a cycle. We expect this to induce an asymmetry in the next sunspot cycle. We look for evidence of this in the observational data and then model it theoretically with our dynamo code. Since actual polar field measurements exist only from the 1970s, we use the polar faculae number data recorded by Sheeley （1991, 2008） as a proxy of the polar field and estimate the hemispheric asymmetry of the polar field in different solar minima during the major part of the twentieth century. This asymmetry is found to have a reasonable correlation with the asymmetry of the next cycle. We then run our dynamo code by feeding information about this asymmetry at the successive minima and compare the results with observational data. We find that the theoretically computed asymmetries of different cycles compare favorably with the observational data, with the correlation coefficient being 0.73. Due to the coupling between the two hemispheres, any hemispheric asymmetry tends to get attenuated with time. The hemispheric asymmetry of a cycle either from observational data or from theoretical calculations statistically tends to be less than the asymmetry in the polar field （as inferred from the faculae data） in the preceding minimum. This reduction factor turns out to be 0.43 and 0.51 respectively in observational data and theoretical simulations.

关键词： Sun activity -- Sun magnetic fields -- sunspots

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Mucinous cystadenoma of the appendix with enterocutaneous fistula:a therapeutic dilemma

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Gastroenterology Report 2015年第1期3卷 86-89页

作者： Nawal k.Jha Dipendra k.Sinha Abhinav Anand Mrigendra k.rai Anjana Gandhi Jitin Yadav Sanjay k.Yadav General Surgery Rajendra Institute of Medical SciencesRanchiIndia

Mucinous cystadenoma of appendix is a rare clinical entity with very few reported cases in the *** on optimal surgical management has not been *** report the case of a 65-year-old female patient who presented with fistula over the right iliac *** tomography(CT)of the abdomen suggested abscess of the parietal *** exploration,a mass was found to be arising from the tip of the retroperitoneal appendix and the retroperitoneum was studded with mucoid *** was carried out and final histopathology revealed mucinous cystadenoma with no evidence of *** patient was discharged *** unusual presentation of this disease,as retroperitoneal psuedomyxoma without any intraperitoneal pathology,prompted us to report this case.

关键词： appendiceal tumours mucinous cystadenoma psuedomyxoma peritonei

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Chemical and physical studies of metallic alloy-based old Indian coins with LIBS coupled with multivariate analysis

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Plasma Science and Technology 2023年第9期25卷 91-103页

作者： Vikas GUPTA Abhishekh kumar rai Tejmani kUMAR Rajendhar JUNJURI G Manoj kUMAR A k.rai Laser Spectroscopy Research Laboratory Department of PhysicsUniversity of AllahabadPrayagraj 211002India Department of Earth and Planetary Sciences University of AllahabadPrayagraj 211002India Advanced Centre of Research in High Energy Materials University of HyderabadHyderabad 500046 India Leibniz Institute of Photonic Technology Jena D-07745Germany

The present work aims to demonstrate the capabilities of Laser-induced Breakdown Spectroscopy(LIBS)coupled with a multivariate technique for rapid quantification and classification of old Indian coins made of various *** old Indian coins in different years of circulation,(1922–1986)were selected for the *** concentrations were determined by Calibration free LIBS(CF-LIBS)*** concentration of cuprum(Cu)is negligible,and aluminum(Al)is maximum in the first five coins,and vice-versa in the remaining eight *** different multivariate methods,Principal Component Analysis(PCA)and Soft Independent Modelling of Class Analogy(SIMCA)have been used to classify and identify the *** classified all thirteen samples into four main alloy *** discernment of unknown samples to their probable class membership of alloy was performed using *** surface hardness(Brinell hardness number)is linearly correlated with the plasma temperature and LIBS intensity *** sample surface of the first and fifth coin belongs to Al-alloy,having the least surface hardness,and it became harder for Cu–Ni alloy,Ni-brass alloy,and bronze *** hardness of the surface is more for bronze sample *** is also observed that the plasma temperature increases monotonically with the Brinell hardness *** analysis provides valuable information on fabrication methodology and explains large diversification in the elementary composition of old coins.

关键词： LIBS metallic alloy stoichiometric ablation PCA SIMCA old indian coins surface hardness

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Dielectric behavior of CaCu_(3)Ti_(4)O_(12) electro-ceramic doped with La,Mn and Ni synthesized by modified citrate-gel route

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Journal of Advanced Ceramics 2013年第2期2卷 119-127页

作者： Laxman SINGH U.S.rai Alok kumar rai k.D.MANDAL Department of Chemistry Centre of Advanced StudyFaculty of ScienceBanaras Hindu UniversityVaranasi 221005U.P.India Department of Materials Science and Engineering Chonnam National University300 Yongbong-dongBukguGwangju 500-757Republic of Korea Department of Applied Chemistry Indian Institute of TechnologyBanaras Hindu UniversityVaranasi 221005U.P.India

The effect of La^(3+),Mn^(2+)and Ni^(2+)doped calcium copper titanate,CaCu_(3)Ti_(4)O_(12)(CCTO),at higher concentrations(CR1 and CR2 with 5 mol%and 10 mol%,respectively),has been examined by semi-wet route at relatively lower *** semi-wet route employs citrate-nitrate gel chemical method using TiO_(2) solid powders.X-ray diffraction(XRD)analysis confirms the formation of single phase in the doped samples sintered at 900℃for 8 *** electron micrographs(SEM)show that the average grain size for CR2 is larger than that of CR1 *** energy dispersive X-ray spectroscopy(EDX)is used to study the percentage compositions of different ions present in both *** constant(εr)and dielectric loss(tanδ)values of CR1 are comparatively higher than those of CR2 ceramic at all measured frequencies and *** nature of temperature-dependent relaxation behavior of the ceramics is also studied by impedance,modulus spectroscopic analysis and confirms Maxwell-Wagner relaxation.

关键词： oxide materials chemical synthesis dielectric properties grain boundaries X-ray diffraction(XRD)

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Prediction of semiconducting behavior in minority spin of Co_2CrZ(Z=Ga,Ge,As):LSDA

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Journal of Semiconductors 2012年第12期33卷 5-10页

作者： D.P.rai R.k.Thapa Department of Physics Mizoram University

Volume optimization was performed to obtain the theoretical lattice constants by using the generalized gradient approximation （GGA）. The electronic and magnetic properties of Heusler alloys CoaCrZ （Z -- Ga, Ge, As） were investigated by using local spin density approximation （LSDA）. Amongst the systems under investigation, CoECrGe and Co2CrGa give I00% spin polarization at the Fermi level （EF）. Co2CrGe and CoECrGa are the most stable half-metallic ferromagnets （HMFs）; their EF lie exactly at the gap of 0.24 eV and 0.38 eV, respectively, in the spin-down channel. Even though CoaCrAs gives a distinct and bigger gap as compared to CoECrGa and CoECrGe, its EF is not located at the middle of the gap in the spin-down channel. We have also found that the total magnetic moments increase as the Z goes from Ga to As. The calculated density of states and band structures show the HMF character for CoECrGe and Co2CrGa.

关键词： GGA half-metallicity DOS spin polarization and band structure

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Structural,electronic,magnetic and optical properties of neodymium chalcogenides using LSDA+U method

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Journal of Semiconductors 2012年第8期33卷 9-14页

作者： A Shankar D P rai Sandeep R k Thapa Condensed Matter Theory Group Department of PhysicsMizoram UniversityAizawlMizoram-796004India

We have studied the electronic, magnetic and optical properties of neodymium chalcogenides by performing LSDA＋ U and full potential linearized augmented plane wave （FP-LAPW） method. The electronic structure calculation shows that the electronic states in Nd-chalcogenides were mainly contributed by Nd-4f electrons near Fermi energy and 3p, 4p and 5p state electrons of X （S, Se and Te）, respectively. We have also studied the absorption of light via the imaginary parts of the dielectric function of Nd-chalcogenides.

关键词： DFT DOS magnetic moment U

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Microstructure transformations and improving wear resistance of austenitic stainless steel additively fabricated by arc-based DED process

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Defence Technology（防务技术） 2024年第8期38卷 194-204页

作者： ashish Yadav Manu Srivastava Prashant k.Jain Sandeep Rathee Hybrid Additive Manufacturing Laboratory Mechanical Engineering DepartmentPDPM Indian Institute of Information TechnologyDesign&ManufacturingJabalpur482005Madhya PradeshIndia FFF Laboratory Mechanical Engineering DepartmentPDPM Indian Institute of Information TechnologyDesign&ManufacturingJabalpur482005Madhya PradeshIndia Department of Mechanical Engineering National Institute of TechnologySrinagarIndia

In this study, austenitic stainless steel(ASS) was additively fabricated by an arc-based direct energy deposition(DED) technique. Macrostructure, microstructure, mechanical characteristics at different spatial orientations(0°, 90°, and 45°), and wear characteristics were evaluated at the deposited structure top, middle, and bottom regions. Results show that austenite(γ) and delta-ferrite(δ) phases make up most of the microstructure of additively fabricated SS316LSi steel. Within γ matrix, δ phase is dispersed both(within and along) grain boundaries, exhibiting a fine vermicular morphology. The bottom, middle,and top regions of WAAM deposited ASS exhibit similar values to those of wrought SS316L in the tensile and impact test findings. Notably, a drop in hardness values is observed as build height increases. During SEM examinations of fractured surfaces from tensile specimen, closed dimples were observed, indicating good ductility of as-built structure. Wear test findings show signs of mild oxidation and usual adhesive wear. By depositing a mechanically mixed composite layer, an increase in the oxidation percentage was discovered to facilitate healing of worn surfaces. The findings of this study will help in design, production and renovation of products/components that are prone to wear. WAAM-deposited ASS has remarkable strength and ability to withstand impacts;it can be used in the production of armour plates for defence applications, mainly military vehicles and aircraft.

关键词： Metal additive deposition Defence applications Arc-based DED Characterization Wear behaviour Fractography

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The meridional circulation of the Sun: Observations, theory and connections with the solar dynamo

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Science China(Physics,Mechanics & Astronomy) 2021年第3期64卷 46-72页

作者： Arnab rai Choudhuri Department of Physics Indian Institute of ScienceBangalore560012India

The meridional circulation of the Sun, which is observed to be poleward at the surface, should have a return flow at some depth. Since large-scale flows like the differential rotation and the meridional circulation are driven by turbulent stresses in the convection zone, these flows are expected to remain confined within this zone. Current observational(based on helioseismology)and theoretical(based on dynamo theory) evidences point towards an equatorward return flow of the meridional circulation at the bottom of the convection zone. Assuming the mean values of various quantities averaged over turbulence to be axisymmetric,we study the large-scale flows in solar-like stars on the basis of a 2D mean field theory. Turbulent stresses in a rotating star can transport angular momentum, setting up a differential rotation. The meridional circulation arises from a slight imbalance between two terms which try to drive it in opposite directions: a thermal wind term(arising out of the higher efficiency of convective heat transport in the polar regions) and a centrifugal term(arising out of the differential rotation). To make these terms comparable,the poles of the Sun should be slightly hotter than the equator. We discuss the important role played by the meridional circulation in the flux transport dynamo model. The poloidal field generated by the Babcock-Leighton process at the surface is advected poleward, whereas the toroidal field produced at the bottom of the convection zone is advected equatorward. The fluctuations in the meridional circulation(with coherence time of about 30-40 yr) help in explaining many aspects of the irregularities in the solar cycle. Finally, we discuss how the Lorentz force of the dynamo-generated magnetic field can cause periodic variations in the large-scale flows with the solar cycle.

关键词： astrophysical plasma solar physics Sun:solar magnetism Sun:helioseismology fluid flow:rotational

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