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Depillaring of total thickness of a thick coal seam in single lift using cable bolts：A case study

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International Journal of Mining Science and Technology 2016年第2期26卷 223-233页

作者： kumar Rakesh Mishra Arvind kumar singh arun kumar singh Amit kumar Ram Sahendr singh Rajendr Central Institute of Mining and Fuel Research (under CSIR) Dhanbad 826015 India Indian School of Mines Dhanbad 826004 India

Explaining fundamentals of application of cable bolting for a thick seam depillaring,this paper summarizes the results of field studies conducted during adoption of this approach in more than fifteen panels of Madhusudanpur 7 pit and incline *** 7.0 m thick Kajora top coal seam of this mine is developed on pillars along the floor horizon to an average height of 3.0 m,leaving a coal band of around 4.0 m along the *** of procured core samples showed that roof strata are easily caveable with a caveability index value of around 2000 *** caveable overlying strata and shallow depth of cover alleviated most of the expected strata mechanics problems of the thick seam ***,extraction of total thickness at shallow cover caused differential-subsidence and cracks on the *** manifestations were immediately tackled to avoid creation of a breathing path for spontaneous heating in the extracted area.

关键词： Cable bolting Thick seam depillaring Extraction height Pillar stability Caveability index

Impact of Selenium on Microtubules Polymarisation of Spermatozoa of Endosulfan Exposed Swiss Albino Mice

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Journal of Life Sciences 2011年第2期5卷 132-135页

作者： Ranjit kumar Jitendra kumar singh Mohammad Ali arun kumar Mahavir Cancer Sansthan ＆ Research Centre Phulwarisharif Patna 801505 India

Pesticide plays a vital role in agricultural, industrial and residemial pest control. In recent years the ‘pesticide problem＇ has been the focus of public interest because these chemicals have a very important role in agriculture but these chemicals also act like endocrine disruptor. Experiments were carried out on 12 weeks old mice with 30 ± 2 gm. b.w. Endosulfan were administered at 3 mg/kg b.w daily by gavage method for five weeks followed by selenium treatment at 10 μg/kg.b.w./day for five weeks. 9 ＋ 2 arrangment were clearly observed in control group mice with well structured dynein and nexin arm while Endosulfan treated group show depolymerised microtubule and 9 ＋ 1 arrangment with degenerated mitochondria. While selenium treated group shows restoration of 9 ＋ 2 arrangement of microtubule. It is evident from study that endosulfan causes depolymerisation of microtubule while selenium administered group show normal polymerized microtubule and restores normal fertility in mice.

关键词： Spermatozoa selenium microtubules dynein arm nexin axoneme depolymerisation Swiss albino mice

Congenital anomalies of coronary artery misdiagnosed as coronary dilatations in Kawasaki disease:A clinical predicament

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World Journal of Clinical Pediatrics 2025年第1期14卷 93-100页

作者： Rakesh kumar Pilania Pallavi L Nadig Suprit Basu Reva Tyagi Abarna Thangaraj Ridhima Aggarwal Munish Arora arun Sharma Surjit singh Manphool singhal Pediatric Allergy Immunology Unit Department of PediatricsAdvanced Pediatrics CenterPost Graduate Institute of Medical Education and ResearchChandigarh 160012ChandīgarhIndia Department of Radiodiagnosis and Imaging Postgraduate Institute of Medical Education and ResearchChandigarh 160012ChandīgarhIndia

BACKGROUND 2D-echocardiography(2DE)has been the primary imaging modality in children with Kawasaki disease(KD)to assess coronary *** To report the presence and implications of incidental congenital coronary artery anomalies that had been misinterpreted as coronary artery abnormalities(CAAs)on *** Records of children diagnosed with KD,who underwent computed tomography coronary angiography(CTCA)at our center between 2013-2023 were *** identified 3 children with congenital coronary artery anomalies in this cohort on *** of CTCA and 2DE were compared in these 3 *** Of the 241 patients with KD who underwent CTCA,3(1.24%)had congenital coronary artery anomalies on CTCA detected *** all 3 patients,baseline 2DE had identified *** was then performed for detailed evaluation as per our unit ***(11-year-boy)amongst the 3 patients had complete KD,while the other two(3.3-year-boy;4-month-girl)had incomplete *** revealed separate origins of left anterior descending artery and left circumflex from left sinus[misinterpreted as dilated left main coronary artery(LCA)on 2DE],single coronary artery(interpreted as dilated LCA on 2DE)and dilated right coronary artery on 2DE in case of anomalous origin of LCA from the main pulmonary *** latter one was subsequently operated *** CTCA is essential for detailed assessment of coronary arteries in children with KD especially in cases where there is suspicion of congenital coronary artery *** solely on 2DE may not be sufficient in such cases,and findings from CTCA can significantly impact therapeutic decision-making.

关键词： Coronary artery abnormalities Congenital coronary artery anomalies Computed tomography coronary angiography Kawasaki disease 2-dimensional echocardiography

Design of a 2-DOF-PID controller using an improved sine-cosine algorithm for load frequency control of a three-area system with nonlinearities

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Protection and Control of Modern Power Systems 2022年第1期7卷 490-507页

作者： Neelesh kumar Gupta Manoj kumar Kar arun kumar singh Department of Electrical Engineering NIT JamshedpurJamshedpurJharkhand 831014India

This paper proposes an improved sine-cosine algorithm(ISCA)based 2-DOF-PID controller for load frequency control.A three-area test system is built for study,while some physical constraints(nonlinearities)are considered for the investigation of a realistic power *** proposed method is used as the parameter optimizer of the LFC control-ler in different *** 2-DOF-PID controllers are used because of their capability of fast disturbance rejection without significant increase of overshoot in set-point *** 2-DOF-PID controllers’efficacy is observed by examining the responses with the outcomes obtained with PID and FOPID *** simulation results with the suggested scheme are correlated with some of the existing algorithms,such as SCA,SSA,ALO,and PSO in three dif-ferent scenarios,i.e.,a disturbance in two areas,in three areas,and in the presence of physical *** addition,the study is extended to a four-area power *** analysis is performed using the Wilcoxon Sign Rank Test(WSRT)on 20 independent *** confirms the supremacy of the proposed method.

关键词： 2-DOF-PID FOPID Load frequency control WSRT Statistical analysis Improved sine-cosine algorithm

Channel estimation and channel tracking for correlated block-fading channels in massive MIMO systems

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Digital Communications and Networks 2018年第2期4卷 138-147页

作者： Suresh Dahiya arun kumar singh Department of Electrical Engineering Indian Institute of Technology Jodhpur Rajasthan 342011 India

This paper presents a channel estimation and tracking method for correlated block-fading channels in massive MIMO wireless cellular systems. In order to conserve resources, the proposed algorithm requires the uplink pilot signal only once, at the start of communication. By utilizing the temporal correlation between consecutive Resource Blocks （RBs） and the error correction capability of turbo codes, the channel matrix in subsequent RBs is estimated at the Base Station （BS） itself using the uplink data of current the RB and the estimated channel matrix of previous the RB. Compared to existing blind estimation methods, the proposed method places fewer limitations on the system settings such as the number of BS antennas, the number of users, and the number of coherent channel usage compared to existing blind estimation methods. Simulation results show that the proposed algorithm provides better performance for a moderate RB size, a high-order of QAM scheme, and a smaller ratio of the number of BS antennas and mobile terminals （N/K）. For a reasonably small N/K （order of 10）, the proposed scheme achieves a lower symbol error probability than the conventional pilot-based estimation approach.

关键词： Massive MIMO Channel estimation Resource block Turbo coding Mobile terminal

A comprehensive review of rectangular duct solar air heaters featuring artificial roughness

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Clean Energy 2024年第5期8卷 186-217页

作者： Ravi Shankar Rajeev kumar arun kumar Pandey Deep singh Thakur Department of Mechanical Engineering Rajkiya Engineering College BandaUttar Pradesh 210201India Department of Mechanical Engineering Institute of Engineering&TechnologyLucknowUttar Pradesh 226021India Department of Mechanical Engineering Bundelkhand Institute of Engineering&TechnologyJhansiUttar Pradesh 284128India

Solar air heaters(SAHs)are widely used solar thermal systems with applications in diverse ***,its effectiveness is re-strained by low convective heat transfer(HT)coefficients at the absorber plate,leading to inefficient HT,and the elevated temperature of the absorber plate causes significant heat losses,reducing thermal *** study addresses these challenges by introducing ribs or roughness on the absorber plate creating turbulence in the airflow,resulting in significant *** research inves-tigates various rib configurations,the influence of rib parameters,performance methods,and arrangements to evaluate their HT and friction *** these rib configurations,a comparative analysis is done on various factors such as the Nusselt number ratio,thermal enhancement factor,friction factor ratio,and thermal efficiency to optimize distinct roughness parameters and rib ar-rangement *** study also provides valuable recommendations from existing literature,offering insights into the effective design,prospects,and implementation of SAH systems.

关键词： solar air heater artificial roughness low heat transfer heating solar energy

Insect feeding deterrent and growth inhibitory activities of scopoletin isolated from Artemisia annua against Spilarctia obliqua （Lepidoptera： Noctuidae）

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Insect Science 2011年第2期18卷 189-194页

作者： arun kumar Tripathi Rajendra singh Bhakuni Shikha Upadhyay Rashmi Gaur Central Institute of Medicinal and Aromatic Plants Lucknow India

Artemisia annua （Asteraceae） is well known for its antimalarial activities due to presence of the compound artemisinin. We isolated a methoxy coumarin from the stem part of A. annua and confirmed its identity as scopoletin through mass spectral data. The structure was established from 1H-nuclear magnetic resonance （NMR）, 13C-NMR. The compound scopoletin was evaluated for its feeding deterrence and growth inhibitory potential against a noxious lepidopteran insect, Spilartctia obliqua Walker. Scopoletin gave FD50（feeding deterrence of 50%） value of 96.7 μg/g diet when mixed into artificial diet. S. obliqua larvae （12-day-old） exposed to the highest concentration （250μg/g diet） of scopoletin showed 77.1% feeding-deterrence. In a growth inhibitory assay, scopoletin provided 116.9% growth inhibition at the highest dose of 250μg/g diet with a GI50 （growth inhibition of 50%） value of 20.9μg/g diet. Statistical analysis showed a concentrationdependent dose response relationship toward both feeding deterrent and growth inhibitory activities. Artemisinin is found mainly in the leaves of A. annua and not in the stems, which are typically discarded as waste. Therefore identification of scopoletin in stems of A. annua may be important as a source of this material for pest control.

关键词： Artemisia annua feeding deterrent growth inhibitor scopoletin Spilartiaobliqua

Mechanical behaviors of deep pillar sandwiched between strong and weak layers

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第5期15卷 1111-1126页

作者： Sahendra Ram Petr Waclawik Jan Nemcik Radovan Kukutsch Ashok kumar arun kumar singh Libin Gong Department of Mining Engineering National Institute of TechnologyRourkelaOdishaIndia Institute of Geonics The Czech Academy of SciencesOstravaCzech Republic University of Wollongong WollongongAustralia CSIR-Central Institute of Mining and Fuel Research DhanbadJharkhandIndia Department of Mining Engineering Indian Institute of Technology(Indian School of Mines)DhanbadJharkhandIndia

A variety of coal room and pillar mining methods have been efficiently practiced at depths of up to 500 m with least strata mechanics ***,for the first time,this method was trialled at depths of 850 e900 m in CSM mine of Czech *** rhomboid-shaped coal pillars with acute corners of 70,surrounded with 5.2 m wide and 3.5e4.5 m high mine roadways,were *** were developed in a staggered manner with their size variation in the Panel II from 83 m×25 m to 24 m×20 m(corner to corner)and Panel V from 35 m×30 m to 26 m×16 *** seam inclined at 12was affected by the unusual slippery slickenside roof bands and sometimes in the floor levels with high vertical stress below strong and massive sandstone *** order to ensure safety,pillars in both the panels were continuously monitored using various geotechnical instruments measuring the induced stresses,side spalling and roof *** panels suffered high amounts of mining induced stress and pillar failure with side-spalling up to 5 m from all *** fracturing of coal pillar sides was controlled by fully encapsulated steel *** induced stress kept increasing with the progress of development of pillars and *** installed in the pillar failed to monitor actual induced stress due to fracturing of coal mass around it which created an apprehension of pillar failure up to its core due to high vertical mining induced *** risk was reduced by carrying out scientific studies including the three-dimensional numerical models calibrated with data from the instrumented *** attempt has been made to study the behavior of coal pillars and their yielding characteristics at deeper cover based on field and simulation results.

关键词： Pillar yielding mechanisms Great depth Numerical modeling Induced stress Pillar dilation Slippery slickenside layer

Age of the earliest transgressive event in the Krishna-Godavari Basin, India: evidence from dinoflagellate cysts and planktonic foraminifera biostratigraphy

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Journal of Palaeogeography 2020年第1期9卷 60-70页

作者： Ashish kumar Mishra Nallamuthu Malarkodi arun Deo singh Dinesh Babu Vandana Prasad Birbal Sahni Institute of Palaeosciences LucknowIndia Department of Geology Jnanabharathi CampusBangalore UniversityBengaluru 560056India Department of Geology Banaras Hindu UniversityVaranasi 221005India Oil India Limited KakinadaIndia.

A combined biostratigraphic study of dinoflagellate cysts and foraminifera was carried out on Early Cretaceous subsurface well cutting sediments from well A(DNG)(2800–2746 m depth)from the Krishna-Godavari Basin,*** last appearance datum of marker species of dinoflagellate cysts and planktonic foraminifera was considered for the construction of the biostratigraphic *** study shows dominance of Early Cretaceous marker dinoflagellate cysts Cassiculosphaeridia magna,Cribroperidinium perforans,Hystrichodinium voigtii,Kleithriasphaeridium eoinodes,and planktonic foraminifera Hedbergella aptiana,Hedbergella mitra,Hedbergella praelippa,Hedbergella tardita,Microhedbergella miniglobularis and Hedbergella mitra *** addition to this,the dinoflagellate cyst data were compared with the dinoflagellate biozones of Austral and Tethyan *** on earlier micropalaeontological records from the Krishna-Godavari Basin and the present study,a latest Barremian-early Aptian age has been determined for the earliest marine transgression in the Krishna-Godavari *** early marine incursion during late Barremian-earliest Aptian in the Krishna-Godavari Basin compared to Albian age in Cauvery Basin suggests the opening of east coast from north to south.

关键词： Biostratigraphy Krishna-Godavari Basin Palaeoenvironment