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Geochemical signatures of potassium metasomatism in anthracite from the Himalayan fold‑thrust belts of Sikkim,India

International Journal of Coal Science & Technology 2022年第2期9卷 48-69页

作者： Santanu Ghosh Anwita Ojha atul kumar Varma Coal Geology and Organic Petrology Laboratory Department of Applied GeologyIndian Institute of Technology(Indian School of Mines)DhanbadJharkhand 826004India Department of Earth Sciences Indian Institute of Technology BombayPowaiMumbaiMaharashtra 400076India

The present study focuses on the inorganic geochemical features of the bituminous coal samples from the Raniganj and the Jharia Basins,as well as the anthracite samples from the Himalayan fold-thrust belts of Sikkim,*** SiO_(2)content(48.05 wt%to 65.09 wt%and 35.92 wt%to 50.11 wt%in the bituminous and anthracite samples,respectively)and the ratio of Al_(2)O_(3)/TiO_(2)(6.97 to 17.03 in the bituminous coal samples and 10.34 to 20.07 in the anthracite samples)reveal the intermediate igneous source rock composition of the *** ratio of the K_(2)O/Al_(2)O_(3)in the ash yield of the bituminous coal samples(0.03 to 0.09)may suggest the presence of kaolinite mixed with montmorillonite,while its range in the ash yield of the anthracite samples(0.16 to 0.27)may imply the presence of illite mixed with *** chemical index of alteration values may suggest the moderate to strong chemical weathering of the source rock under sub-humid to humid climatic *** plot of the bituminous coal samples in the A–CN–K diagram depicts the traditional weathering trend of parent rocks,but the anthracite samples plot near the illite feld and are a bit ofset from the weathering *** may imply the plausible infuences of the potassium-metasomatism at post coalifcation stages,which is further supported by high K_(2)O/Na_(2)O ratio(29.88–80.13).The Fourier transform infrared spectra further reveal the hydroxyl stretching intensity of illite in the anthracite samples substantiating the efect of the epigenetic *** decrease in total kaolinite intensity/compound intensity of quartz and feldspar may provide additional evidence towards this epigenetic event.

关键词： Himalayan fold-thrust belts Anthracite Potassium metasomatism Kaolinite to quartz-feldspar intensity ratio Montmorillonite stretching and bending intensities Illite-stretching frequency

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Journal of Ocean Engineering and Science 2023年第2期8卷 111-123页

作者： Raj kumar Ravi Shankar Verma atul kumar Tiwari Department of Mathematics Faculty of Engineering&TechnologyVeer Bahadur Singh Purvanchal UniversityJaunpur222003India Department of Mathematics Motihari College of EngineeringMotihari845401BiharIndia

This work is devoted to get a new family of analytical solutions of the(2+1)-coupled dispersive long wave equations propagating in an infinitely long channel with constant depth,and can be observed in an open sea or in wide *** solutions are obtained by using the invariance property of the similarity transformations method via one-parameter Lie group *** repeated use of the similarity transformations method can transform the system of PDEs into system of *** adequate restrictions,the reduced system of ODEs is *** simulation is performed to describe the solutions in a physically meaningful *** profiles of the solutions are simulated by taking an appropriate choice of functions and constants involved *** each animation,a frame for dominated behavior is *** exhibit elastic multisolitons,single soliton,doubly solitons,stationary,kink and parabolic *** results are significant since these have confirmed some of the established results of *** et al.(2020)and *** et al.(2020).Some of their solutions can be deduced from the results derived in this *** results in the existing literature are different from those in this work.

关键词： Dispersive long wave equations Solitons Invariants Lie-group Similarity solutions

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Cameron ulcers:An atypical source for a massive upper gastrointestinal bleed

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World Journal of Gastroenterology 2012年第35期18卷 4959-4961页

作者： Samir Kapadia Sophia Jagroop atul kumar Department of Medicine Stony Book Univer sity School of MedicineStony BrookNY 11794United States Gastroenterology and Hepatol ogy Northport VA Medical CenterNorthportNY 11768United States

Cameron lesions represent linear gastric erosions and ulcers on the crests of mucosal folds in the distal neck of a hiatal hernia(HH).Such lesions may be found in upto 50% of endoscopies performed for another *** typically asymptomatic,these may rarely present as acute,severe upper gastrointestinal bleed(GIB).The aim is to report a case of a non-anemic 87-year-old female with history of HH and atrial fibrillation who presented with hematemesis and melena resulting in hypovolemic *** esophagogastroduodenoscopy was required to identify multiple Cameron ulcers as the *** in a patient with HH should involve meticulous visualization of hernia neck and surrounding *** ulcers should be considered in all patients with severe,acute GIB and especially in those with known HH with or without chronic anemia.

关键词： Cameron lesion Upper gastrointestinalbleeding Shock Hiatal hernia

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Hydro-uvarovite from Mantle Peridotites of Naga Hills Ophiolite: A Mineral Tracer for Neo-Tethyan Mantle Wedge Metasomatism

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Acta Geologica Sinica(English Edition) 2024年第4期98卷 867-877页

作者： Anisha VERENCAR Abhishek SAHA Nilanjana SORCAR Sohini GANGULY Pankaj kumar atul kumar SINGH CSIR-National Institute of Oceanography Dona PaulaGoa 403004India School of Earth Ocean and Atmospheric SciencesGoa UniversityTaleigao PlateauGoa 403206India National Centre for Earth Science Studies ThiruvananthapuramKeralaIndia Inter University Accelerator Centre(IUAC) New Delhi 110067India North-Eastern Hill University ShillongMeghalaya 793022India

Hydrous Cr-bearing uvarovite garnets are rare in natural occurrences and belong to the ugrandite series and exist in binary solid solutions with grossular and andradite garnets. Here, we report the occurrence of hydrous uvarovite garnet having Cr_(2)O_(3) upto 19.66 wt% and CaO of 32.12–35.14 wt% in the serpentinized mantle peridotites of Naga Hills Ophiolite(NHO), India. They occur in association with low-Cr diopsides. They are enriched in LILE(Ba, Sr), LREEs, with fractionating LREE-MREE [avg.(La/Sm)_(N) = 2.16] with flat MREE/HREE patterns [avg.(Sm/Yb)_(N) = 0.95]. Raman spectra indicate the presence of hydroxyl(OH^(–)) peaks from 3500 to 3700 cm^(-1). Relative abundances in fluid mobile elements and their close association with clinopyroxenes are suggestive of the formation of uvarovite garnets through low temperature metasomatic alteration of low-Cr diopsides by hydrothermal slab fluids. The high LREE concentration and absence of Eu anomaly in the garnet further attest to alkaline nature of the transporting slab dehydrated fluid rather the involvement of low-p H solution. The chemical characteristics of the hydroxyl bearing uvarovite hosted by the mantle peridotite of NHO deviate from the classical features of uvarovite garnet, and their origin is attributed to the fluid-induced metasomatism of the sub arc mantle wedge in a suprasubduction zone regime.

关键词： uvarovite hydroxyl metasomatic alteration low-Cr diopsides serpentinization mantle peridotite

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Review on the phosphate-based conversion coatings of magnesium and its alloys

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International Journal of Minerals,Metallurgy and Materials 2022年第7期29卷 1435-1452页

作者： Debasis Saran atul kumar Sivaiah Bathula David Klaumünzer Kisor K Sahu School of Minerals Metallurgical and Materials EngineeringIndian Institute of Technology BhubaneswarBhubaneswar 752050India Group Innovation(COI Battery-Metals) Volkswagen AGWolfsburg 38440Germany Virtual and Augmented Reality Centre of Excellence(VARCOE) Indian Institute of Technology BhubaneswarBhubaneswar 752050India

Magnesium(Mg)and its alloys are lightweight as well as biocompatible and possess a high strength-to-weight ratio,making them suitable for many industries,including aerospace,automobile,and *** major challenge is their high susceptibility to corrosion,thereby limiting their *** considerably lower reduction potential of Mg compared to other metals makes it vulnerable to galvanic *** oxide layer on Mg offers little corrosion resistance because of its high porosity,inhomogeneity,and *** conversion coatings(CCs)belong to a distinct class because of underlying chemical reactions,which are fundamentally different from other types of ***,a CC acts as an intermediate sandwich layer between the base metal and an aesthetic *** chromate CCs offer superior performance compared to phosphate CCs,yet still they release carcinogenic hexavalent chromium ions(Cr^(6+));therefore,their use is prohibited in most European nations under the Registration,Evaluation,Authorization and Restriction of Chemicals legislation ***-based CCs are a cost-effective and environment-friendly ***,this review primarily focuses on different types of phosphate-based CCs,such as zinc,calcium,Mg,vanadium,manganese,and *** discusses their mechanisms,current status,pretreatment practices,and the influence of various parameters-such as pH,temperature,immersion time,and bath composition-on the coating *** challenges associated with phosphate CCs and future research directions are also elaborated.

关键词： phosphate conversion coatings magnesium alloys corrosion zinc phosphate conversion coatings calcium phosphate conversion coatings magnesium phosphate conversion coatings

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Spectral narratives of microstructural restyling and their controls on hydrocarbon generation potential from coal

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International Journal of Coal Science & Technology 2023年第3期10卷 167-189页

作者： Tushar Adsul Santanu Ghosh Anwita Ojha Sudip Bhattacharyya atul kumar Varma Coal Geology and Organic Petrology Laboratory Department of Applied GeologyIndian Institute of Technology(Indian School of Mines)DhanbadJharkhand 826004India Department of Geology Mizoram UniversityAizawlMizoram 796004India Specialized Coal Petrography Laboratory Natural Energy ResourcesMission II-BGeological Survey of IndiaDK-6Sector-IlSalt Lake CityKolkataWest Bengal 700091India

The low to medium-rank Tertiary coals from Meghalaya,India,are explored for the first time for their comprehensive micro-structural characterization using the FTIR and Raman ***,results from these coals are compared with the Permian medium and high-rank coals to understand the microstructural restyling during coalification and its controls on hydrocarbon *** coal samples are grouped based on the mean random vitrinite reflectance values to record the transformations in spectral attributes with increasing coal *** aliphatic carbon and the apparent aromaticity respond sharply to the first coalification jump(R:0.50%)during low to medium-rank transition and anchizonal metamorphism of the high-rank ***,the Raman band intensity ratio changes during the first coalification jump but remains invari-able in the medium-rank coals and turns subtle again during the onset of pregraphitization in high-rank coals,revealing a polynomial trend with the coal *** Rock-Eval hydrogen index and genetic potential also decline sharply at the first coalification ***,an attempt to comprehend the coal microstructural controls on the hydrocarbon poten-tial reveals that the Tertiary coals comprise highly reactive aliphatic functionalities in the type I-S kerogen,along with the low paleotemperature(74.59-112.28℃)may signify their potential to generate early-mature ***,the presence of type II-II admixed kerogen,a lesser abundance of reactive moieties,and overall moderate paleotemperature(91.93-142.52℃)of the Permian medium-rank coals may imply their mixed hydrocarbon ***,anchizonal metamorphism,polycondensed aromatic microstructure,and high values of paleotemperature(~334.25 to~366.79℃)of the high-rank coals indicate a negligible potential of producing any hydrocarbons.

关键词： Early mature oil generation Meghalaya high-sulfur coal Type II-S kerogen Microstructural ordering Coalification jump Hydrocarbon generation potential

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Extraction of tectonic imprints using geospatial techniques:Evidence from Mandakini River basin,Uttarakhand,India

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Journal of Mountain Science 2024年第11期21卷 3720-3738页

作者： atul kumar PATIDAR Girish Ch.KOTHYARI Manmohan KAUSHIK Sushil KHANDURI Department of Petroleum Engineering and Earth Sciences UPESDehradun 248007India KainGeotech Consultancy Dehradun 248007India

The existing literature discussed only the aerial aspect and provided a brief description of tectonic-geomorphic correlation with field *** present study we applied power law equations to estimate basin asymmetry factor(AF),Transverse topographic asymmetric factor(T),Hypsometric Integral(HI),longitudinal profile,stream length gradient index(SL),steepness index(Ksn),Chi(χ),and knick point(Kp)analysis to examine the response of tectono-climatic fluctuations in the Mandakini River basin,central Uttarakhand *** decouple the causative tectono-climatic factors,we employed geospatial and Stream Power Incision Modeling(SPIM)*** is a globally accepted tool to predict an equilibrium state between fluvial erosion rates and the escalating function of stream *** is actively applied in modeling the transformation of river systems especially in rugged topographic *** present study covers SPIM-based morphometric assessment of the tectonically sensitive Mandakini River basin between Ramgarh Thrust(RT)and Vaikrita Thrust(VT)in the central region of Uttarakhand *** the upper reaches of the basin,U-shaped glaciated valleys dominate the landscape,while a rolling topography and deeply incised narrow valleys are depicted towards the ***,to understand the response of active tectonic over geomorphology,the drainage basin has been divided into two separate zones from the confluence point near the Rampur *** modeling outcomes indicate that the Mandakini drainage basin is in a disequilibrium state where channels are actively incising to ***,AF of 32 and 70 indicate leftward tilting in the upper reaches and rightward tilting in the lower reaches of the basin,*** HI value of 0.38 indicates a stage of maturity,characterized by a concave shape *** on the analysis it may be concluded that the fragile lithology and tectono-climatic fluctuations are dominantly controlling the topography and valle

关键词： Stream Power Incision Model(SPIM) Transverse Topographic Asymmetry Factor(T) Knick points Hypsometric curve Mandakini River Garhwal Himalaya

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First contact investigations and compliance to treatment in patients with uveitis

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International Journal of Ophthalmology(English edition) 2023年第11期16卷 1820-1826页

作者： Anuja Patil Sanjeev Gupta Pradeep Venkatesh Mousumi Banerjee Vinod kumar Rohan Chawla Shorya Vardhan Azad atul kumar Dr.Rajendra Prasad Centre for Ophthalmic Sciences All India Institute of Medical SciencesNew Delhi 110029India

AIM:To ascertain the pattern of investigations at first contact in uveitic patients and evaluate compliance to ***:An observational study comprised of 201 uveitic patients presenting for the first time to our centre from January 2019 to June *** information regarding systemic investigations undertaken by specialists at the time of first contact and the cost of these investigations were reviewed on the first visit to our *** with the treatment was determined and reasons behind non-compliance were evaluated on the first follow-up in patients who had no improvement in clinical signs and ***:The mean age of the study group was 35.35±14.1y and gender composition was 59.7%males and 40.3%*** uveitis was observed in 45.3%of patients,intermediate uveitis in 31.8%of patients,posterior uveitis in 14.9%of patients and panuveitis in 8.0%of *** with a systemic disease was evident in 17.9%of *** compared with standard guidelines and uveitis patterns,systemic investigations were identified to be relevant only in 38.3%of ***-compliance to treatment was documented in 22.4%of *** reasons for non-compliance were inadequate counselling by the treating physician about treatment in 26.7%of patients and a busy schedule at work/school in 22.2%of ***:Significant number of investigations performed at first contact is found to be contrary to standard guidelines and are not contributory to the *** a quarter of patients in this study are found to be non-compliant with the *** is more challenging to achieve in school-going children and working *** availability of comprehensive,periodically updated,evidence-based guidelines on the role of investigations and the use of trained counsellors may help to channelize proper evaluation and improve compliance to treatment,respectively,in patients with uveitis.

关键词： uveitis compliance investigations first contact

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Organo-Petrographic and Pore Facets of Permian Shale Beds of Jharia Basin with Implications to Shale Gas Reservoir

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Journal of Earth Science 2017年第5期28卷 897-916页

作者： Vinod Atmaram Mendhe Subhashree Mishra Ranjit G.Khangar Alka Damodhar Kamble Durgesh kumar atul kumar Varma H.Singh Sujeet kumar Mollika Bannerjee CSIR-Central Institute of Mining and Fuel Research GSI-Geological Survey of India Central Region IIT (ISM)-Department of Chemical Engineering Indian Institute of Technology (ISM) IIT (ISM)-Department of Applied Geology Indian Institute of Technology (ISM)

The shale deposits of Damodar Valley have received great attention since preliminary studies indicate their potential for shale gas. However, fundamental information allied to shale gas re- servoir characteristics are still rare in India, as exploration is in the primary stage. In this study, Ba- rakar shale beds of eastern part of Jharia Basin are evaluated for gas reservoir characteristics. It is evident that Barakar shales are carbonaceous, silty, contains sub-angular flecks of quartz and mica, irregular hair-line fractures and showing lithological variations along the bedding planes, signifying terrestrial-fluviatile deposits under reducing environment. The values of TOC varies from 1.21 wt.% to 17.32 wt.%, indicating good source rock potentiality. The vitrinite, liptinite, inertinite and mineral matter ranging from 0.28 vol.% to 12.98 vol.%, 0.17 vol.% to 3.23 vol.%, 0.23 vol.% to 9.05 vol.%, and 74.74 vol.% to 99.10 vol.%, respectively. The ternary facies plot of maceral composition substan- tiated that Barakar shales are vitrinite rich and placed in the thermal-dry gas prone region. The low values of the surface area determined following different methods point towards low methane storage capacity, this is because of diagenesis and alterations of potash feldspar responsible for pore blocking effect. The pore size distribution signifying the micro to mesoporous nature, while Type II sorption curve with the H2 type of hysteresis pattern, specifies the heterogeneity in pore structure mainly combined-slit and bottle neck pores.

关键词： shale gas petrographic composition surface area pore disposition pore volume.

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Synthesis, Crystal Structure and Antibacterial Activity of 1-((2-Chloroquinolin-3-yl)-methyl)-pyridin-2(1H)-one

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Chinese Journal of Structural Chemistry 2010年第11期29卷 1612-1617页

作者： S. Mohana Roopan Venkatesha R. Hathwar F. Nawaz Khan atul kumar Kushwaha Organic & Medicinal Chemistry Research Laboratory Organic Chemistry Division School of Advanced Sciences VIT University Solid State and Structural Chemistry Unit Indian Institute of Science

On the basis of the interesting structures and biological activities exhibited by several heterocyclic systems possessing the pyridone nucleus such as mappcine and camptothecin, we have planed to design the synthesis, crystal studies and antibacterial activity of the new 1-（（2- chloroquinolin-3yl）-methyl）-pyridine-2（1H）-one building block. An X-ray analysis has provided valuable insight into the effect of steric factors on the three-dimensional shape of this compound which serves as a useful advanced intermediate in the synthesis of these biologically active molecules. A multistep synthesis of camptothecin （5） has been designed by retrosynthetic analysis as part of an ongoing program on lead anticancer drug.

关键词： crystal structure 1-((2-chloroquinolin-3yl)-pyridine-2(1H)-one

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