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Palaeodepositional environment,implications of Glossopteris flora,and organic matter characteristics from the Lower Permian,Karo Open Cast Mine,East Bokaro Coalfield,Damodar Basin,India

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Journal of Palaeogeography 2024年第3期13卷 528-546页

作者： Sankar Suresh kumar Pillai Rose Ann Sebastian Runcie Paul Mathews Srikanta Murthy Anju Saxena Mrutyunjaya Sahoo suraj kumar Sahu Gulshan kumar Dhingra Birbal Sahni Institute of Palaeosciences 53 University RoadLucknow-226007UPIndia Academy of Scientific and Innovative Research(AcSIR) Ghaziabad-201002India Department of Geology School of Earth Science SystemsCentral University of KeralaKasaragod-671316KeralaIndia Department of Geology Ravenshaw UniversityCuttack-753003OdishaIndia Department of Botany Sri Dev Suman Uttarakhand UniversityUttarakhand-249145India

The present study deals with the Early Permian floral diversity,palaeoenvironment,palaeoclimate and depositional setting using a multiproxy approach that includes morphotaxonomy,palynology,and organic geochemistry of Karo OCM(Open Cast Mine),East Bokaro Coalfield,Damodar Gondwana Basin,*** Permian sediments of Peninsular India are widely regarded as fluvial,along with some marine *** macroplant fossil assemblage exhibits the presence of Glossopteridales,comprising Glossopteris,Gangamopteris,and Vertebraria,as well as Coniferales,which includes *** palynological assemblage encompasses the dominance of the striate bisaccate pollen Faunipollenites *** the subdominance of the non-striate bisaccate pollen Scheuringipollenites *** glossopterid *** megafloral and palynofloral assemblage confirms the biostratigraphical age to be Late Barakar palynoflora of Kungurian *** studied morphological characteristics,including small to large Glossopteris leaves exhibiting a lanceolate shape,acute apices,and acute cuneate or tapering bases,as well as entire margins with narrower lamina and narrow meshes,suggest the existence of a dense forest with the prevalence of a warm and humid climate during their *** organic geochemical characterization based on functional group and biomarker analyses reveals the diagenetic effects on organic *** symmetric(~2865-2855 cm^(-1))and asymmetric stretching(~2930-2910 cm^(-1))peaks are identifiable in coal samples,whereas they are absent in carbonaceous *** A-factor vs.C-factor plot suggests that the kerogen type is type Ⅲ,which can generate mainly gaseous *** vitrinite reflectance studies(R_(r) av.1.1%)show increased maturity of the samples,which is supported by the n-alkane distribution pattern and the absence of hopane *** Indian floral assemblages in contemporary of southern Gondwana continents reveal a stronger inclination/affinity with th

关键词： Glossopteris Palynomorph FTIR GCMS Gondwana Permian Palaeoclimate

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Free-electron crystals for enhanced X-ray radiation

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Light(Science & Applications) 2024年第7期13卷 1299-1309页

作者： Lee Wei Wesley Wong Xihang Shi Aviv Karnieli Jeremy Lim suraj kumar Sergio Carbajo Ido Kaminer Liang Jie Wong School of Electrical and Electronic Engineering Nanyang Technological University50 Nanyang AvenueSingapore 639798Singapore. Solid State Institute and Faculty of Electrical and Computer Engineering Technion–Israel Institute of TechnologyHaifa 3200003Israel. School of Electrical Engineering Fleischman Faculty of EngineeringTel Aviv UniversityTel Aviv 69978Israel Department of Applied Physics Stanford UniversityStanfordCA 94305USA. Science Mathematics and TechnologySingapore University of Technology and Design8 Somapah RoadSingapore 487372Singapore. Electrical and Computer Engineering Department UCLA420 WestwoodLos AngelesCA 90095USA. Physics and Astronomy Department UCLA475 Portola PlazaLos AngelesCA 90095USA. SLAC National Accelerator Laboratory Stanford University2575 Sand Hill RoadMenlo ParkCA 94025USA

Bremsstrahlung—the spontaneous emission of broadband radiation from free electrons that are deflected by atomic nuclei—contributes to the majority of X-rays emitted from X-ray tubes and used in applications ranging from medical imaging to semiconductor chip ***,we show that the bremsstrahlung intensity can be enhanced significantly—by more than three orders of magnitude—through shaping the electron wavefunction to periodically overlap with atoms in crystalline ***,we show how to shape the bremsstrahlung X-ray emission pattern into arbitrary angular emission profiles for purposes such as unidirectionality and ***,we find that these enhancements and shaped emission profiles cannot be attributed solely to the spatial overlap between the electron probability distribution and the atomic centers,as predicted by the paraxial and nonrecoil theory for free electron light *** work highlights an unprecedented regime of free electron light emission where electron waveshaping provides multi-dimensional control over practical radiation processes like *** results pave the way towards greater versatility in table-top X-ray sources and improved fundamental understanding of quantum electron-light interactions.

关键词： overlap attributed arbitrary

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Comment on: Observation of peripheral refraction in myopic anisometropia in young adults

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International Journal of Ophthalmology(English edition) 2024年第7期17卷 1385-1386页

作者： suraj kumar Chaurasiya Mahendra Singh Pradeep Agarwal Yu-Qin Du Yue-Hua Zhou Ming-Wei Ding Ming-Xu Zhang Yu-Juan Guo Shan-Shan Ge Department of Optometry and Vision Science CL Gupta Eye InstituteRam Ganga Vihar Phase II(Extn.)MoradabadUttar Pradesh 244001India Department of Paediatric and Neuro Ophthalmology CL Gupta Eye InstituteRam Ganga Vihar Phase II(Extn.)MoradabadUttar Pradesh 244001India Eye School of Chengdu University of TCM Ineye Hospital of Chengdu University of TCMChengdu 610036Sichuan ProvinceChina Beijing Ming Vision and Ophthalmology Beijing 100010China

Dear Editor,We read with great interest the recently published article titled“Observation of peripheral refraction in myopic anisometropia in young adults”by Du et al[1].The study conducted at the InEye Hospital of Chengdu University of TCM provides valuable insights into the relationship between anisometropia and peripheral refraction in myopic young *** commend the authors for their thorough investigation and adherence to ethical *** the study contributes significantly to our understanding of myopic anisometropia,we would like to draw attention to some limitations that merit consideration for a comprehensive interpretation of the findings.

关键词： Observation young insight

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Generation scenarios of anodic structures and experimental realization of turbulence in unmagnetized plasma

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Plasma Science and Technology 2020年第8期22卷 90-98页

作者： Prince ALEX suraj kumar SINHA Departimento di Fisica G.Occhialini Universita degli studi di MilanoBicoccaI-20126Italy Department of Physics Pondicherry UniversityKalapetPuducherry 605014India

In the present work,we report development of a DC glow discharge plasma(GDP)set-up to study controlled evolution of anodic structures having distinctive geometry,size and layers,generated in front of a positively biased electrode,submerged in unmagnetized *** such an anodic structure,we have also investigated the condition under which the turbulence is *** of these structures,generated in front of a positively biased electrode,depends on multiple parameters such as the ratio of anode to cathode size,electrode separation,gas pressure,biasing configuration such as anode bias,cathode bias and grounding *** attempted to classify different anodic structures observed experimentally,as anode glow,fireball,anode spot,double layer and multiple double layers(MDLs)based on its physical *** these structures the present investigation is focused on *** number of layers,observed in MDLs varied from as high as six to as low as zero,by controlling the operating discharge parameters,*** were carried out using Langmuir *** analysis of floating potential fluctuations corresponds to a multiple anodic structure showed emergence of turbulence,at its critical stage,satisfying condition for self-organized criticality(SOC).This was identified with three slopes observed in the power spectrum,resembling the sand-pile ***,the GDP is completely different from that of the magnetically confined plasma,the nature of turbulence observed with SOC,is very similar to that observed in the scrape of layer of fusion ***,the present investigation could provide new approach to study turbulence of similar nature,under an experimental condition that is free from the complexities of complicated field geometries used in confinement devices.

关键词： glow discharge plasma anode structure multiple anodic double layer turbulence unmagnetized plasma fireball

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Feedback model of secondary electron emission in DC gas discharge plasmas

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Plasma Science and Technology 2018年第2期20卷 128-133页

作者： Saravanan ARUMUGAM Prince ALEX suraj kumar SINHA Department of Physics Pondicherrry University

Feedback is said to exist in any amplifier when the fraction of output power in fed back as an ***,in gaseous discharge ions that incident on the cathode act as a natural feedback element to stabilize and self sustain the *** present investigation is intended to emphasize the feedback nature of ions that emits secondary electrons（SEs）from the cathode surface in DC gas *** average number of SEs emitted per incident ion and non ionic species（energetic neutrals,metastables and photons）which results from ion is defined as effective secondary electronemission coefficient（ESEEC,Eg）.In this study,we derive an analytic expression that corroborates the relation betweenEg and power influx by ion to the cathode based on the feedback theory of an *** addition,experimentally,we confirmed the typical positive feedback nature of SEEfrom the cathode in argon DC glow *** experiment is done for three different cathode material of same dimension（tungsten（W）,copper（Cu）and brass）under identical discharge conditions（pressure：0.45 mbar,cathode bias：-600 V,discharge gab：15 cm and operating gas：argon）.Further,we found that theEg value of these cathode material controls the amount of feedback power given by *** difference in feedback leads different final output i.e the power carried by ion at cathode（Pi C￠∣）.The experimentally obtained value of Pi C￠∣is 4.28 W,6.87 W and9.26 W respectively for W,Cu and *** addition,the present investigation reveals that the amount of feedback power in a DC gas discharges not only affect the fraction of power fed back to the cathode but also the entire characteristics of the discharge.

关键词： feedback secondary electron emission DC gas discharges power influx by ion at cathode cathode temperature

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Prediction-Adaptation-Resilience(PAR)approach-A new pathway towards future resilience and sustainable development of urban landscape

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Geography and Sustainability 2021年第2期2卷 127-133页

作者： suraj kumar Mallick Department of Geography Vidyasagar UniversityMidnaporeWest Bengal-721102India

Urban land-use planning,especially in the peripheral region,has become an issue in contemporary urban ***,urban resilience is very indispensable for future urban land use planning and ***,consistent urban proliferation can be coped through Prediction-Adaptation-Resilience(PAR),to accom-plish future urban land use and sustainable development of any growing up urban areas ***,different dynamic simulation models,*** automata-Markov model,artificial neural network,are used to project and predict any urban areas’spatial ***,the adaptation strategies are taken to assess the urban land use transformation in the past and present *** strategies help to strengthen urban land use planning using an integrated supply and demand ***,this study checks the resilience of how much it will be threatened or saved for future sustainable urban developmental goals and urban ***,it is important to establish a conceptual framework to achieve Sustainable Development Goals(SDGs)based on principles of the PAR *** the on-going adaptation of sustainability,resilience,and rapid urban transformation in the developing cities requires clear and explicit definitions that are embedded with the recent and particular ***,government and policy makers should draw their attention to make proper urban landscape planning and adaptation strategies for the future urban expansion in a holistic way by maintaining appropriate urban resilience.

关键词： Land use transformation Prediction-Adaptation-Resilience(PAR) Sustainable Development Goals urban growth urban resilience

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Development of a drill energy utilization index for aiding selection of drill machines in surface mines

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International Journal of Mining Science and Technology 2017年第3期27卷 393-399页

作者： kumar suraj Rahul Talreja Murthy V.M.S.R. Department of Mining Engineering Indian School of Mines Dhanbad India

Drill machines used in surface mines, particularly in coal, is characterized by a very poor utilization （around 40%） and low availability （around 60%）. The main purpose of this study is to develop a drill selec- tion methodology and simultaneously a performance evaluation technique based on drill cuttings produced and drilling rate achieved. In all 28 blast drilled through were investigated. The drilling was accomplished by 5 different drill machines of Ingersoll-Rand and Revathi working in coal mines of Sonepur Bazari （SECL） and Block-II （BCCL）. The drills are Rotary and Rotary Percussive type using tri- cone rock roller bits. Drill cuttings were collected and sieve analysis was done in the laboratory. Using Rosin Ramler Diagram, coarseness index （CI）, mean chip size （d）, specific-st trace area （SSA） and charac- teristic particle size distribution curves for all the holes drilled were plotted. The predictor equation for drill penetration rate established through multiple regressions was found to have a very good correlation with an index of determination of 0.85. A comparative analysis of particle size distribution curves was used to evaluate the drill efficiency. The suggested approach utilises the area under the curve, after the point of trend reversal and brittleness ratio of the respective bench to arrive at drill energy utilization index （DEUI）, for mapping of drill machine to bench, The developed DEU1 can aid in selecting or mapping a right machine to right bench for achieving higher penetration rate and utilizations.

关键词： Drill cutting parameter Coarseness index Mean chip size Specific surface area Particle size distribution curves Drill energy ptilization index

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Assessment of surface and subsurface waterlogging, water level fluctuations, and lithological variations for evaluating groundwater resources in Ganga Plains

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International Journal of Digital Earth 2013年第3期6卷 276-296页

作者： Arvind Chandra Pandey suraj kumar Singh M.S.Nathawat Dipankar Saha Department of Remote Sensing Birla Institute of TechnologyMesraRanchiIndia Central Ground Water Board Ministry of Water ResourcesPatnaIndia

In the present study,the multi-temporal satellite images of IRS P6 LISS III were used to map waterlogging dynamics over different *** area of 594.36 km2(6.75%)and 4.17 km^(2)(0.04%)was affected by surface waterlogging during pre and postmonsoon season,*** average annual groundwater level fluctuations were calculated using 18 years(1990-2007)pre and postmonsoon groundwater level data to identify the areas which are under groundwater induced waterlogging *** soil map clearly indicates that salinity and sodicity exhibit the highest severity and occur in areas with shallow groundwater *** hydrogeomorphical units mapped using IRS P6 LISS III satellite images are flood plain,alluvial plain,paleochannels,and oxbow *** study revealed that 44.65%areas have very good to excellent groundwater *** litholog data clearly indicate an alternating sequence of clay and sand in which deep aquifers made up of coarse sand would be best suited for adequate water supply and good groundwater *** integrated study utilizing digital spatial data pertaining to waterlogging,soil salinity,water level fluctuation,and lithological variation proved that planning of any surface and subsurface water resources development activity should be taken up after assessments of said parameters.

关键词： waterlogging salinity Ganga plain digital earth groundwater resources digital data

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Assessing the impacts of current and future changes of the planforms of river Brahmaputra on its land use-land cover

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Geoscience Frontiers 2023年第4期14卷 100-122页

作者： Jatan Debnath Dhrubajyoti Sahariah Durlov Lahon Nityaranjan Nath Kesar Chand Gowhar Meraj Pankaj kumar suraj kumar Singh Shruti Kanga Majid Farooq Department of Geography Gauhati UniversityJalukbariAssamIndia GB Pant National Institute of Himalayan Environment(NIHE) Himachal Regional Centre(Himachal Pradesh)KulluIndia Department of Ecology Environment and Remote SensingGovernment of Jammu and KashmirKashmir 190018India Institute for Global Environmental Strategies Hayama 240-0115Japan Centre for Sustainable Development Suresh Gyan Vihar UniversityJaipur 302017India Centre for Climate Change and Water Research(C3WR) Suresh Gyan Vihar UniversityJaipur 302017India Department of Geography School of Environment and Earth SciencesCentral University of PunjabVPO-GhuddaBathinda 151401India

River bankline migration is a frequent phenomenon in the river of the floodplain ***,channel dynamics-related changes in land use and land cover(LULC)are becoming a risk to the life and property of people living in the vicinity of rivers.A comprehensive evaluation of the causes and consequences of such changes is essential for better policy and decision-making for disaster risk reduction and *** present study assesses the changes in the Brahmaputra River planform using the GIS-based Digital Shoreline Analysis System(DSAS)and relates it with the changing LULC of the floodplain evaluated using the CA-Markov *** this study,the future channel of the Brahmaputra River and its flood plain’s future LULC were forecasted to pinpoint the erosion-vulnerable ***-eight years(1973–2021)of remotely sensed data were applied to estimate the rate of bankline *** was observed that the river’s erosion-accretion rate was higher in early times than in more recent *** left and right banks’average shifting rates between 1973 and 1988 were -55.44 m/y and -56.79 m/y,respectively,while they were-17.25 m/y and -48.49 m/y from 2011 to *** left bank of the river Brahmaputra had more erosion than the right,which indicates that the river is shifting in the leftward direction(Southward).In this river course,zone A(Lower course)and zone B(Middle course)were more adversely affected than zone C(Upper course).According to the predicted result,the left bank is more susceptible to bank erosion than the right bank(where the average rate of erosion and deposition was -72.23 m/y and 79.50 m/y,respectively).The left bank’s average rate of erosion was -111.22 m/*** research assesses the LULC study in conjunction with river channel dynamics in vulnerable areas where nearby infrastructure and settlements were at risk due to channel *** degree of accu-racy was verified using the actual bankline and predicted bankline,as well as the actual LULC map

关键词： Channel shifting Erosion-Accretion Bankline Prediction DSAS CA-Markov Brahmaputra River

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Changes in post-keratoplasty astigmatism after suture removal:refraction vs tomography vs aberrometry

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International Journal of Ophthalmology(English edition) 2021年第11期14卷 1707-1713页

作者： suraj kumar Chaurasiya Jagadesh C.Reddy Pravin K.Vaddavalli Christopher J.Rapuano Brien Holden School of Optometry and Vision Sciences L V Prasad Eye Institute(LVPEI)Hyderabad 500034India Cataract and Refractive Surgery Services The Cornea InstituteL V Prasad Eye Institute(LVPEI)Hyderabad 500034India Comea Service Wills Eye HospitalPhiladelphiaPennsylvania 19107USA

AIM:To analyse the changes in magnitude and orientation of astigmatism after suture removal(SR)in keratoplasty eyes as measured by refraction,tomography,and ***:Twenty-six eyes of 25 patients after optical keratoplasty requiring SR to reduce the astigmatism during the follow-up period were prospectively *** with poor quality topography scans or if there were no sutures in the steepest semi meridian were *** distance visual acuity(CDVA),manifest refraction,corneal tomography and aberrometr y were per formed on all patients before and after ***:The mean age of the patients was 40.8±14.4 *** keratoplasty was performed in 23 eyes(89%)and deep anterior lamellar keratoplasty was done in 3 eyes(11%).There was a statistically significant reduction in the magnitude of refractive,tomographic and aberrometry astigmatism after SR(P<0.001)at 2 h after suture *** mean net reduction of the astigmatism was greater as measured by corneal tomography compared to refractive astigmatism(P<0.05).There was no statistically significant change in refractive astigmatism between 2 h and 2 mo after SR(P=0.55).Vector calculations demonstrated a greater amount of undercorrection in the tomography group and the rotational error was more towards counterclockwise *** monocular log MAR CDVA improved from 0.57 D to 0.49 D after SR(P=0.002).CONCLUSION:The net reduction in the magnitude of astigmatism after SR is greater in the tomography and aberrometry *** one episode of SR,there is no difference in the aberration profile.

关键词： keratoplasty astigmatism suture removal

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