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Frontiers of Structural and Civil Engineering 2023年第11期17卷 1643-1661页

作者： Lalit KUMAR Dhrutiman dey Biranchi PANDA Nelson MUTHU Department of Mechanical Engineering Indian Institute of Technology GuwahatiAssam 781039India

Three-dimensional concrete printing(3DCP)can proliferate the industrialization of the construction sector,which is notoriously conservative and indolent toward ***,the mechanical behavior of 3DCP should be characterized and modeled considering the interfaces when its performance is thoroughly compared to that of the existing concrete construction *** study presents an experimental and numerical investigation of uniaxial compression and three-point bending(TPB)tests on extruded 3DCP beams in different loading *** orientation of translational and depositional interfaces with respect to the direction of loading influenced the *** the elastic and post-damage behavior of the 3DCP specimens were compared with those of the conventionally cast specimen under quasi-static loading *** the higher compressive strength of the casted specimen,the flexural strength of the 3DCP specimens was *** study employed the finite element and cohesive zone models of the appropriate calibrated traction-separation law to model fracture in the notched TPB ***,the real-time acoustic emission test revealed the nature of failure phenomenon of three-dimensional-printed specimens under flexion,and accordingly,the cohesive law was *** predicted load-displacement responses are in good agreement with the experimental ***,the effects of cohesive thickness and notch shape on the performance under bending were explored through parametric studies.

关键词： three-dimensional printing anisotropy flexure compression cohesive zone model finite element model

Influence of bank vegetation and gravel bed on velocity and Reynolds stress distributions

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International Journal of Sediment Research 2009年第2期24卷 236-246页

作者： Hossein AFZALIMEHR Subhasish dey Department of Water Engineering Isfahan University of Technology Department of Civil Engineering Indian Institute of Technology

This paper presents the results of a laboratory flume experimental study on the interaction of bank vegetation and gravel bed on the flow velocity(primarily on the location of the maximum velocity,Umax) and the Reynolds stress distributions. The results reveal that the dip of the maximum velocity below the water surface is up to 35% of flow depth and the difference between Umax and the velocity at the water surface is considerable in the presence of vegetation on the walls. The zone of the log-law varies from y/h=2 up to 15 percent of flow depth and it does not depend on distance from the wall. Deviation of the velocity profile in the outer layer over a gravel bed with vegetation cover on the walls is much larger than the case of flow over a gravel bed without vegetation cover on the walls. The presence of vegetation on the walls changes uniform flow to non-uniform flow. This fact can be explained by considering the nonlinear Reynolds stress distribution and location of maximum velocity in each profile at different distances across the flume. The Reynolds stress distributions at the distance 0.02 m from the wall have negative values and away from the wall,they change the sign taking positive values with specific convex form with apex in higher location. Average of von Karman constant κ for this study is equal to 0.16. Based on κ=0.16,the methods of Clauser and the Reynolds stress are compatible for determination of shear velocity.

关键词： Bank vegetation Uniform flow Reynolds stress Gravel bed Von Karman constant

Enrichment of carbon recovery of high ash coal fines using air fluidized vibratory deck separator

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International Journal of Coal Science & Technology 2017年第3期4卷 262-273页

作者： Laxmikanta Sahu Shobhana dey Department of Fuel and Mineral Engineering Indian Instituteof Technology (Indian School of Mines) DhanbadJharkhand 826004 India Mineral Processing Division CSIR-National MetallurgicalLaboratory Jamshedpur Jharkhand 831007 India

Coal is primarily beneficiated by wet gravity methods. The wet processing of coal is an efficient practice. However, it introduces the moisture in the range of 6%-15%, depending upon the size of coal which is as detrimental as ash content to the heating value of coal. Dry beneficiation of coal fines was carried out using an air fluidized vibrating table in which the coal particles get separated from the heavier mineral particles as a result of horizontal and vertical stratification. Two level factorial design matrix was used to optimize and assess the interactive effects of the operational parameters of a pneumatic table viz. deck eccentric, side tilt and air flow rate on the clean coal yield and its ash content. Double stage processing was found to be more effective for reducing the ash content of the clean coal. Initial stage of processing at a higher ash level generates a reject of high ash with low combustibles. Cleaning of the rougher concentrate at 34%-35% ash level shows significant improvement in the organic efficiency （88.6%） and useful heat value of clean coal （15690 kJ/kg）. The performance of air fluidized vibrating deck was measured by Ep value which is 0.18.

关键词： Air flow rate · Deck eccentric · Segregation of particles ·Separation efficiency

Interfacial instability of sand patterns induced by turbulent shear flow

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International Journal of Sediment Research 2021年第4期36卷 449-456页

作者： Sk Zeeshan Ali Subhasish dey Department of Civil Engineering Indian Institute of Technology Hyderabad Department of Civil Engineering Indian Institute of Technology Kharagpur Department of Hydraulic Engineering State Key Laboratory of Hydro-Science and Engineering Tsinghua University

When a turbulent shear flow above a plane sand surface entrains sand grains, it generates a variety of sand patterns. Fluvial sand forms two major interfacial patterns: meso-scale dunes and antidunes, and large-scale bars. Measurements have evidenced that under erosive conditions, meso-scale patterns either change to or coexist with large-scale patterns. However, it remains elusive what exactly drives the switching of interfacial patterns and how the switching occurs. Here, we showdcombing a flow model with a grain transport model, allowing for both the surface and suspended sand fluxes dthat the switching of patterns emerges from the shear-driven complex feedback between grain transport and topographic perturbations. The switching predominantly depends on the magnitudes of the Rouse number and the grain size to undisturbed flow depth ratio. The model offers quantitative predictions of the maximum amplification of sand patterns and unveils a new attraction erepulsion phenomenon.

关键词： Instability Sand patterns Turbulent flow Sediment transport

Synthesis of Mg(OH)_(2) micro/nano flowers at room temperature

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Journal of Advanced Ceramics 2013年第2期2卷 173-179页

作者： Pradip Sekhar DAS Arjun dey Ashok Kumar MANDAL Nitai dey Anoop K.MUKHOPADHYAY CSIR-Central Glass and Ceramic Research Institute Kolkata 700032India Thermal Systems Group ISRO Satellite CentreVimanapura PostBangalore 560017India

The inexpensive and green method of synthesis for self-assembled micro/nano structures is an important area of emerging *** structures can be chemically tuned with predesigned functional ***,they hold very good promise for future applications,e.g.,biomedicine,electronic device,solar energy,gas *** we report for the first time an inexpensive and green method for chemical deposition of magnesium hydroxide(Mg(OH)_(2))micro/nano flowers in thin films on commercial soda lime silica glass substrates at room *** identical conditions,chemically synthesized Mg(OH)_(2) powders are also prepared in absence of the soda lime silica glass *** condition that favors the growth of micro/nano flowers in thin films is identified from X-ray diffraction(XRD),scanning electron microscopy(SEM),field emission scanning electron microscopy(FE-SEM),transmission electron microscopy(TEM),and energy dispersive X-ray spectroscopy(EDX)***,the possible growth mechanism of micro/nano flowers in thin films is discussed.

关键词： magnesium hydroxide(Mg(OH)2) flower-like microstructure chemical deposition film

Algorithmic approaches for optimizing electronic control unit time using multi-rate sampling

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Control Theory and Technology 2018年第3期16卷 173-190页

作者： Rajorshee RAHA Pallab DASGUPTA Soumyajit dey Department of Computer Science and Engineering Indian Institute of Technology Kharagpur India

With the emerging migration of automotive and other distributed control platforms from federated to integrated architectures, the need for optimal utilization of ECU （electronic control unit） bandwidth will become a key requirement in the implementation of embedded control features. This paper advocates the partitioning of the operating space of the plant and the use of minimal sampling rates in each partition without compromising the overall quality of control. At the heart of the proposed methodology are our algorithms that enable the choice of the partitions and the sampling rate for each partition. We demonstrate the efficacy of our methods on two case studies, namely an anti-lock braking system and a lane departure warning system. We also study the use of a supervisory controller that controls the switching among sampling rates for a combination of the two features.

关键词： Sampling period adaptive control stability automotive software embedded control system

Morphological and Microstructural Evidences of Paleo-Seisminc Occurrences in an Earthquake Prone Zone of Tripura, India

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Journal of Earth Science 2014年第2期25卷 289-298页

作者： Sudip dey Sushmita Paul Prasamita Sarkar Department of Geography and Disaster Management Tripura University

Morphology and structure of a faulted zone not only express the present status but also preserve the evidences of early seismo-tectonic occurrences. The present paper aims to assess the morphological as well as subsurface evidences of early seismo-tectonic occurrences in an earth- quake prone zone of Baromura Hill, Tripura. Tectonically this is a part of Tripura-Mizoram fold belt and fall within Zone V of BIS seismic map. In the present research the tectonic lineaments of Baromura Hill was identified by using satellite data. For that purpose, Landsat TM shortwave in- frared, midwave infrared and near infrared was selected for preparing suitable band combination. A classified thermal infrared was used for final operation. From the remote sensing operation five clear tectonic lineaments were found. During the field work rock samples were collected for labora- tory testing. Thin sections of the rocks show that complex stress pattern was developed during the geological past which caused strong seismo-tectonic occurrences. From the study it can be assessed that though the nature of the paleo-seismic occurrences were almost same but the level of impact varied through spatial and temporal scales due different physical properties and arrangements. It is also clear from the study that the geological evolution of this place is more complex as it seems to be. Tectonic and geomorphic processes worked together through the Tertiary and Quaternary periods and played equally important role for landform evolution.

关键词： morphology tectonic lineament microstructure grain scale deformation Baromura Hill geomorphic process.

Chromium-induced membrane damage: protective role of ascorbic acid

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Journal of Environmental Sciences 2001年第3期13卷 272-275页

作者： Sankar Kumar dey Prasunpriya Nayak Somenath Roy Department of Human Physiology with Community Health Vidyasagar UniversityMidnapore 721102West BengalIndia

Importance of chromium as environmental toxicant is largely due to impact on the body to produce cellular toxicity. The impact of chromium and their supplementation with ascorbic acid was studied on plasma membrane of liver and kidney in male Wistar rats (80-100g body weight). It has been observed that the intoxication with chromium (i.p.) at the dose of 0.8 mg/100g body weight per day for a period of 28 days causes significant increase in the level of cholesterol and decrease in the level of phospholipid of both liver and kidney. The alkaline phosphatase, total ATPase and Na\++\|K\++\|ATPase activities were significantly decreased in both liver and kidney after chromium treatment, except total ATPase activity of kidney. It is suggested that chromium exposure at the present dose and duration induce for the alterations of structure and function of both liver and kidney plasma membrane. Ascorbic acid (i.p. at the dose of 0.5 mg/100g body weight per day for period of 28 days) supplementation can reduce these structural changes in the plasma membrane of liver and kidney. But the functional changes can not be completely replenished by the ascorbic acid supplementation in response to chromium exposure. So it is also suggested that ascorbic acid (nutritional antioxidant) is useful free radical scavenger to restrain the chromium induced membrane damage.

关键词： chromium liver kidney membrane ascorbic acid

Analysis of Progressively Type-Ⅱ Inverted Generalized Gamma Censored Data and Its Engineering Application

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Computer Modeling in Engineering & Sciences 2024年第10期141卷 459-489页

作者： Refah Alotaibi Sanku dey Ahmed Elshahhat Department of Mathematical Sciences College of SciencePrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh11671Saudi Arabia Department of Statistics St.Anthony’s CollegeShillong793001India Faculty of Technology and Development Zagazig UniversityZagazig44519Egypt

A novel inverted generalized gamma(IGG)distribution,proposed for data modelling with an upside-down bathtub hazard rate,is *** many real-world practical situations,when a researcher wants to conduct a comparative study of the life testing of items based on cost and duration of testing,censoring strategies are frequently *** this point of view,in the presence of censored data compiled from the most well-known progressively Type-Ⅱ censoring technique,this study examines different parameters of the IGG *** a classical point of view,the likelihood and product of spacing estimation methods are *** Fisher information and the deltamethod are used to obtain the approximate confidence intervals for any unknown parametric function of the *** the Bayesian paradigm,the same traditional inferential approaches are used to estimate all unknown ***-Chain with Monte-Carlo steps are considered to approximate all Bayes’*** numerical comparisons are presented to examine the performance of the proposed methodologies using various criteria of ***,using several optimality criteria,the optimumprogressive censoring design is *** highlight how the proposed estimators can be used in practice and to verify the flexibility of the proposed model,we analyze the failure times of twenty mechanical components of a diesel engine.

关键词： Inverted generalized gamma censoring spacing function likelihood Bayesian optimal plan

Oxygen Functionalization-Induced Charging Effect on Boron Active Sites for High-Yield Electrocatalytic NH_(3) Production

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Nano-Micro Letters 2022年第12期14卷 464-480页

作者： Ashmita Biswas Samadhan Kapse Ranjit Thapa Ramendra Sundar dey Institute of Nano Science and Technology(INST) Sector-81MohaliPunjab 140306India Department of Physics SRM University-APAmaravatiAndhra Pradesh 522240India

Ammonia has been recognized as the future renewable energy fuel because of its wide-ranging applications in H_(2) storage and transportation *** order to avoid the environmentally hazardous Haber-Bosch process,recently,the third-generation ambient ammonia synthesis has drawn phenom-enal attention and thus tremendous efforts are devoted to developing efficient electrocatalysts that would circumvent the bottlenecks of the electrochemical nitrogen reduction reaction(NRR)like competitive hydrogen evolution reac-tion,poor selectivity of N_(2) on catalyst ***,we report the synthesis of an oxygen-functionalized boron carbonitride matrix via a two-step pyrolysis *** conductive BNCO(1000)architecture,the compatibility of B-2p_(z) orbital with the N-2p_(z) orbital and the charging effect over B due to the C and O edge-atoms in a pentagon altogether facilitate N_(2) adsorption on the B edge-active *** optimum electrolyte acidity with 0.1 M HCl and the lowered anion crowding effect aid the protonation steps of NRR via an associative alternating pathway,which gives a sufficiently high yield of ammonia(211.5μg h^(−1) mg_(cat)^(−1))on the optimized BNCO(1000)catalyst with a Faradaic efficiency of 34.7%at−0.1 V vs *** work thus offers a cost-effective electrode material and provides a contemporary idea about reinforcing the charging effect over the secured active sites for NRR by selectively choosing the electrolyte anions and functionalizing the active edges of the BNCO(1000)catalyst.

关键词： C-doped boron nitride O-functionalization Density-functional theory(DFT) Charging effect Nitrogen reduction reaction Ambient ammonia synthesis