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Quaternary tectonic history of seismically active intraplate Kachchh Rift Basin,western India:A review

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geodesy and geodynamics 2022年第3期13卷 192-204页

作者： girish Ch.Kothyari Raj Sunil Kandregula Rakesh Dumka gaurav Chauhan Ajay kumar Taloor Institute of Seismological Research GandhinagarGujaratIndia CSIR-national geophysical Research Institute HyderabadTelanganaIndia Department of Earth and Environmental Science KSKV Kachchh UniversityBhujIndia Department of Remote Sensing and gIS University of JammuJammuIndia

Since the recorded historical period,the Kachchh Rift Basin(KRB)has encountered numerous moderate to large magnitude *** to the series of seismicity research so far,there are several important points of debate regarding the tectonic history and evolution of the KRB,especially during the Quaternary ***,the main objective of the present research is to inspect and perceive the association amongst the strain build-up,earthquake provenance,landform evolution and progression as archived by the Quaternary deposits of the *** previous studies demonstrated the evolutions of various landforms,such as the uplifted fluvial terraces,formation of the gorges,uplifted alluvial fan sequences,which can be ideally used to reconstruct the neotectonic history along active faults of *** this,the analysis of the accessible and supportive data,including geochronology provided by earlier studies along with some new dataset for a superior knowledge on the Quaternary tectonic forces prevailing in the KRB,have been carried ***,we also emphasized the differences and directions for future potential research *** observations of variability in uplift rates across the various active faults in the KRB suggest a complex geological history during the Quaternary *** results show that the vertical uplift rate along the significant active faults range from 0.8 to 2.8 mm/yr,demonstrating the variable tectonic stress regime prevailing in the *** uplift rates constricted from geomorphic and chronological aspects suggest that the tectonic movements within the Kachchh intraplate region is regulated by the fault segments and the present tectonic stress field is in accordance with the encompassing tectonic stress field associated with the northward movement of the Indian plate corresponding to the Eurasian plate.

关键词： Quaternary tectonics Uplift rates Active faults Kachchh Rift Basin

Editorial note for the geodesy and geodynamics journal special issue:Remote Sensing and gIS applications in crustal deformation and neotectonics

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geodesy and geodynamics 2022年第3期13卷 189-191页

作者： Ajay kumar Taloor girish Chandra Kothyari Shangmin Zhao Rajwant Mayank Joshi Department of Remote Sensing and gIS University of JammuJammu 180006India Active Fault Research group Institute of Seismological ResearchGandhinagar 382009India Department of Surveying and Mapping Taiyuan University of Technology No.79Yingze West RoadTaiyuan 030024China Science and Engineering Research Board Government of IndiaNew Delhi 110016India gB Pant Institute of Himalayan Environment Sikkim Regional Centre Pangthang 737101India

Crustal deformation and neotectonics are well-understood phenomena that happen almost on every part of the Earth and have some diastrophic effects on the Earth’s *** understand these effects,Remote Sensing(RS)and(gIS)have sharpened the human ability to learn about the scientiflc reasons for the Earth’s dynamic activities,including active tectonics and surface landform changes in spatially and temporally.

关键词： tectonics Earth crustal

Evolution of fracture permeability due to co-colloidal bacterial transport in a coupled fracture-skin-matrix system

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geoscience Frontiers 2012年第4期3卷 503-514页

作者： n.natarajan g.Suresh kumar EWRE Division Department of Civil EngineeringIndian Institute of TechnologyMadrasChennai 600036India Department of Ocean Engineering Indian Institute of TechnologyMadrasChennai 600036India

A numerical model is developed for investigating the evolution of fracture permeability in a coupled fracture-matrix system in the presence of fracture-skin with simultaneous colloidal and bacte- rial transport, by taking into account the effects of thermal stress and silica precipitation/dissolution, which is computed using linear reaction kinetics. The non-linear coupled equations are numerically modeled using the fully implicit finite difference method and a constant continuous source is adopted while modeling thermal, contaminant, colloidal and bacterial transport. Due to co-colloid bacterial trans- port under non-isothermal conditions, in a coupled fracture-skin-matrix system, the fracture apertures vary spatially, with a corresponding pressure variation for a constant discharge. A series of numerical experiments were conducted for analyzing the spatial variation of fracture aperture in response to the combined effects of thermal stress, silica precipitation/dissolution, and simultaneous colloidal and bacte- rial transport in the presence of the fracture-skin. The simulation results suggest that temperature and contaminant concentration of the mobile fluid within the fracture increases with reduction in initial frac- ture aperture. The pattern of variation followed by the fracture aperture is nearly the same in the presence and absence of bacterial transport but the magnitude of the fracture aperture is low under the influence of bacterial transport. The variation in the fracture aperture resulting from precipitation-dissolution and thermoelastic stress is significant when the fracture aperture is very low and reduces with increment in fracture aperture. The variation in fracture aperture and pressure remains the same for both undersaturated and supersaturated fluid entering the fracture due to the influence of bacterial transport at the inlet of the fracture.

关键词： Bacterial transport Colloidal transport Fracture permeability Fracture skin Precipitation-dissolution

Investigations on Low Speed Axial Compressor with Forward and Backward Sweep

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Journal of Thermal Science 2007年第2期16卷 121-133页

作者： M.govardhan O.g.Krishna kumar n.Sitaram Thermal Turbomachines Laboratory Department of Mechanical EngineeringIndian Institute of Technology MadrasChennai 600036India

In the recent past, experimental studies have shown some advantages of blade lean and sweep in axial compressors. As most of the experimental results are combined with other features, it is difficult to determine the effect of individual parameters on the performance of the compressor. The present numerical studies are aimed at understanding the performance and three-dimensional flow pattern at the exit of swept and unswept rotors. Three rotors, namely; unswept, 200 forward swept and 200 backward swept rotors are analysed with a specific intention of understanding the pattern of the blade boundary layer flow. The analysis was done using a fully three-dimensional viscous CFD code CFX-5. Results indicated reduction in pressure rise with sweep. Backward sweep is detrimental as far as the performance near endwalls is considered. On the other hand total pressure loss in the wake in mid span region is less with backward sweep, which favours its application here. However, backward sweep adversely affects the stall margin. The ability of the forward sweep to deflect the streamlines towards hub gets diminished at low flow rates. Forward sweep changes the streamline pattern in such a way that the suction surface streamlines are deflected towards the hub and the pressure surface streamlines are deflected towards the easing. An opposite behaviour is observed in backward swept rotors.

关键词： Sweep pressure rise streamline shift stall margin blade loading

Magnetic fabric and geomorphic characteristic of neotectonic activity along strike direction of north Almora Thrust,Kumaun Lesser Himalaya,India

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geodesy and geodynamics 2022年第3期13卷 261-274页

作者： Ritu Chauhan girish Ch Kothyari Surendra S.Bhakuni Pitamber Dutt Pant Ajay kumar Taloor CAS in geology Kumaun UniversityNainitalIndia Institute of Seismological Research RaisanGandhinagar382009India Wadia Institute of Himalayan geology DehradunIndia Department of Remote Sensing and gIS University of JammuJammuIndia

Structurally,the north Almora Thrust(nAT),is placed in the northern proximity of the Almora nappe(An)in the Kumaun Lesser *** nAT is characterized by the presence of a zone of mylonitic rocks of basal Saryu Formation(1800±100 Ma)in the hanging wall and the metasedimentaries of Inner Lesser Himalayan rocks as the footwall *** nAT has been dextrally offset by two estabilished maj or faults *** River Fault(SRF)in Saryu Valley and Dwarahat-Chaukhutia Fault(DCF)in Ramganga *** present study,we identified four new faults,based on field study,geomorphic landform and magnetic fabric *** faults are n-S trending Pancheshwar Fault,nE-SW Rameshwer Fault,nnE-SSW trending Kosi Fault,and nnE-SSW trending gagas Fault(gF).Our results show that the zone is bound by cross cutting relation with nAT and these fault zones are comparatively more active than other ***,we suggest that the steep and nW-SE orientation of magnetic foliation within the nAT zone is a result of nE-SW oriented progressive regional *** magnetic foliations represent the unseen internal foliations in the rocks developed due to preferred alignment of magnetic minerals and can be found through the Anisotropy of magnetic susceptibility(AMS)*** in the alignment of the field and magnetic foliations are developed due to superimposed brittle deformation along the faults over the pre-existing field *** foliations represent the impact of last stage deformation and significant to find brittle deformation and finite strain in the rocks of the study *** lowering of anisotropy(Pj)away from the fault zone represents distribution of strain across the nAT *** fabric confirms the presence of faults developed across the nAT zone and also explains the deformation pattern along these *** geomorphic anomalies and steepness changes across the nAT zone are correlated with active deformation along the nAT and associated transverse

关键词： north Almora Thrust(nAT) geomorphology Anisotropy of magnetic susceptibility neotectonics Kumaun Lesser Himalaya

Hydro-hypsometric analysis of tropical river basins,Southwest Coast of India using geospatial technology

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Journal of Mountain Science 2016年第5期13卷 939-946页

作者： gopinath girish Ambili gopalan KAMALAMMA n P JESIYA Kuriachan LEMOOn Centre for Water Resources Development and Management Kerala 673571India

The key aspect in planning and management of water resources is to analyze the runoff potential and erosion status of the river *** the detailed investigation of hydrological response freely available Cartosat-1(IRS-P5) data was used for the preparation of digital elevation model(DEM).The runoff potential and type of erosive process of 22 river basins originating in the global biodiversity hotspot of Western ghats,was inferred through hypsometric *** parameters like Hypsometric integral(HI),maximum concavity(Eh),coordinates of slope inflection point(I) given by a* and h* and normalized height of hypsometric curve(h) were extracted from the hypsometric curves and used for understanding the hydrological *** the hypsometric curves,the landform evolution processes were *** of diffusive and fluvial processes in slope degradation of the river basins was *** with lesser area(nd to have a positive correlation between hypsometric integral and basin area,whereas for large basins no such correlation *** on the study,river basins can be prioritized for the appropriate conservation measures.

关键词： Hypsometry Runoff potential Erosion status Cartosat-1 data River Basins

Magnetohydrodynamic flow and heat transfer of a hybrid nanofluid over a rotating disk by considering Arrhenius energy

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Communications in Theoretical Physics 2021年第4期73卷 9-20页

作者： M gnaneswara Reddy naveen kumar R B C Prasannakumara n g Rudraswamy K ganesh kumar Department of Mathematics Acharya Nagarjuna University CampusOngole-523001India Department of Studies and Research in Mathematics Davangere UniversityShivagangothriDavangere-577007KarnatakaIndia Department of Mathematics P.C.Jabin Science CollageHubballi-580031India

This research work explores the effect of hybrid nanoparticles on the flow over a rotating disk by using an activation energy ***,we considered molybdenum disulfide and ferro sulfate as nanoparticles suspended in base fluid *** magnetic field is pragmatic normal to the hybrid nanofluid flow *** derived nonlinear ordinary differential equations are non-dimensionalized and worked out numerically with the help of Maple software by the RKF-45 *** scientific results for a non-dimensionalized equation are presented for both nanoparticle and hybrid nanoparticle *** of various predominant restrictions on flow and thermal fields are *** estimation for friction factor,local nusselt number and Sherwood number are also *** reveal that the reduction of the heat transfer rate is greater in hybrid nanoparticles when compared to nanoparticles for increasing values of Eckert number and the thermal field enhances for the enhanced values of volume fraction.

关键词： porous medium MHD hybrid nanoparticles activation energy

Review: Progress and Trends in Ultrasonic Vibration Assisted Friction Stir Welding

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Journal of Harbin Institute of Technology(new Series) 2018年第3期25卷 16-42页

作者： najib Ahmad Muhammad Chuansong Wu girish kumar Padhy Institute of Materials Joining Shandong University

This paper aims to reviewthe state-of-the-art of ultrasonic vibration assisted friction stir welding(UVAFSW) process. Particular attention has been paid on the modes of ultrasonic exertion,experimental results and effects of ultrasonic vibrations on process effectiveness and joint quality. The trends of various aspects with and without ultrasonic vibrations in FSW process are studied and presented. The influence of ultrasonic vibrations on welding loads, temperature history, weld morphology, material flow, weld microstructure and mechanical properties are revisited. Ultrasonic assisted FSW offers numerous advantages over the conventional FSW process. The superimposing of high-frequency vibrations improves various phenomena of the process and the physical,metallurgical,mechanical and tribological properties of the welded joint. The ultrasonic assisted FSW process has a potential to benefit the industry sector. A checklist listing the materials and process parameters used in the documented studies has been presented for quick reference.

关键词： friction stir welding ultrasonic vibration assisted FSW acoustic softening welding load thermal history material flow microstructure mechanical properties

Transition Metal Free Chemoselective Reduction ofα,β-Unsaturated Ketones to Saturated Ketones Using Tosyl Hydrazide as a Hydrogen Donor

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Chinese Journal of Chemistry 2015年第2期33卷 181-184页

作者： Yarabally R girish Kanchipura R Raghavendra Dasappa nagaraja Kothanahally S Sharath kumar Sheena Shashikanth Deparment of Studies in Chemistry ManasagangothriUniversity of MysoreMysore 570006India Department of Pg Studies in Chemistry Government Science CollegeChitradurga 577501India

An efficient,inexpensive and simple method for the reduction of variousα,β-unsaturated ketones to corre-sponding saturated ketones using tosyl hydrazide as a hydrogen donor in DMF using calcium oxide powder has been reported.A variety of enones underwent reduction without forming undesirable side *** chemose-lectivity,broad functional group tolerance and good yields are the noteworthy features of this protocol.

关键词： α,β-unsaturated carbonyl compounds tosyl hydrazide transition metal free saturated ketones