期刊文献+
共找到13篇文章
< 1 >
每页显示 20 50 100
Mathematical Modeling of Moored Ship Motion in Arbitrary Harbor utilizing the Porous Breakwater
1
作者 Prachi Priya prashant kumar +1 位作者 Gulshan Rajni 《China Ocean Engineering》 SCIE EI CSCD 2023年第5期738-752,共15页
The motion of the moored ship in the harbor is a classical hydrodynamics problem that still faces many challenges in naval operations,such as cargo transfer and ship pairings between a big transport ship and some smal... The motion of the moored ship in the harbor is a classical hydrodynamics problem that still faces many challenges in naval operations,such as cargo transfer and ship pairings between a big transport ship and some small ships.A mathematical model is presented based on the Laplace equation utilizing the porous breakwater to investigate the moored ship motion in a partially absorbing/reflecting harbor.The motion of the moored ship is described with the hydrodynamic forces along the rotational motion(roll,pitch,and yaw)and translational motion(surge,sway,and heave).The efficiency of the numerical method is verified by comparing it with the analytical study of Yu and Chwang(1994)for the porous breakwater,and the moored ship motion is compared with the theoretical and experimental data obtained by Yoo(1998)and Takagi et al.(1993).Further,the current numerical scheme is implemented on the realistic Visakhapatnam Fishing port,India,in order to analyze the hydrodynamic forces on moored ship motion under resonance conditions.The model incorporates some essential strategies such as adding a porous breakwater and utilizing the wave absorber to reduce the port’s resonance.It has been observed that these tactics have a significant impact on the resonance inside the port for safe maritime navigation.Therefore,the current numerical model provides an efficient tool to reduce the resonance within the arbitrarily shaped ports for secure anchoring. 展开更多
关键词 boundary element method Laplace equation porous breakwater partially reflecting/absorbing harbor wall moored ship motion
下载PDF
The Characterization and Study of Physical Parameters of Ge Modified Se-Sn-Pb Chalcogenide System 被引量:1
2
作者 prashant kumar Vivek Modgil V. S. Rangra 《New Journal of Glass and Ceramics》 2013年第4期116-121,共6页
In the present paper, we have studied the effect of Ge addition on the physical properties of Se-Sn-Pb chalcogenide ma- terial. The necessary physical parameters which have important role in determining the structure ... In the present paper, we have studied the effect of Ge addition on the physical properties of Se-Sn-Pb chalcogenide ma- terial. The necessary physical parameters which have important role in determining the structure and strength of the material viz. constraints, coordination number etc. have been calculated. The increasing trend has been found in cohesive energy, heat of atomization and mean bond energy. The glass transition has been studied using the Tichy-Ticha and Lankhorst approaches, which also increases with the increasing Ge contents. The increase in these physical parameters is due to the increasing covalent character in the material. 展开更多
关键词 QUATERNARY CHALCOGENIDE Glasses Heat of ATOMISATION Mean Bond Energy Glass Transition Tempera-ture SEM
下载PDF
MCDA techniques used in optimization of weights and ratings of DRASTIC model for groundwater vulnerability assessment 被引量:1
3
作者 prashant kumar Reema Sharma Subhasis Bhaumik 《Data Science and Management》 2022年第1期28-41,共14页
DRASTIC is a very simple and common model used for the assessment of groundwater to contamination.This model is widely used across the world in various hydrogeological environments for groundwater vulnerability assess... DRASTIC is a very simple and common model used for the assessment of groundwater to contamination.This model is widely used across the world in various hydrogeological environments for groundwater vulnerability assessment.The Ohio Water Well Association(OWWA)developed DRASTIC model in 1987.Over the years,several modifications have been made in this model as per the need of the regional assessment of groundwater to contamination.This model has fixed weights for its parameters and fixed ratings for the sub-parameters under the main parameters.The weights and ratings of DRASTIC parameters were fixed on the basis of Delphi network technique,which is the best technique for the consensus-building of experts,but it lacks scientific explanations.Over the years,several optimization techniques have been used to optimize these weights and ratings.This work intends to present a critical analysis of decision optimization techniques used to get the optimum values of weights and ratings.The inherent pros and cons and the optimization challenges associated with these techniques have also been discussed.The finding of this study is that the application of MCDA optimization techniques used to optimize the weights and ratings of DRASTIC model to assess the vulnerability of groundwater depend on the availability of hydrogeological data,the pilot study area and the level of required accuracy for earmarking the vulnerable regions.It is recommended that one must choose the appropriate MCDA technique for the particular region because unnecessary complex structure for optimization process takes more time,efforts,resources,and implementation costs. 展开更多
关键词 DRASTIC Model Vulnerability index Analytic Hierarchy Process MCDA techniques Neural networks Fuzzy logic
下载PDF
Boundary Element Modeling of Multiconnected Ocean Basin in Visakhapatnam Port Under the Resonance Conditions
4
作者 prashant kumar Prachi PRIYA RAJNI 《China Ocean Engineering》 SCIE EI CSCD 2021年第5期662-675,共14页
A mathematical model has been developed to analyze the influence of extreme water waves over multiconnected regions in Visakhapatnam Port,India by considering an average water depth in each multiconnected regions.In a... A mathematical model has been developed to analyze the influence of extreme water waves over multiconnected regions in Visakhapatnam Port,India by considering an average water depth in each multiconnected regions.In addition,partial reflection of incident waves on coastal boundary is also considered.The domain of interest is divided mainly into two regions,i.e.,open sea region and harbor region namely as Region-I and Region-II,respectively.Further,Region-II is divided into multiple connected regions.The 2-D boundary element method(BEM)including the Chebyshev point discretization is utilized to solve the Helmholtz equation in each region separately to determine the wave amplification.The numerical convergence is performed to obtain the optimum numerical accuracy and the validation of the current numerical approach is also conducted by comparing the simulation results with existing studies.The four key spots based on the moored ship locations in Visakhapatnam Port are identified to perform the numerical simulation.The wave amplification at these locations is estimated for monochromatic incident waves,considering approximate water depth and different reflection coefficients on the wall of port under the resonance conditions.In addition,wave field analysis inside the Visakhapatnam Port is also conducted to understand resonance conditions.The current numerical model provides an efficient tool to analyze the amplification on any realistic ports or harbors. 展开更多
关键词 boundary element method amplification factor Helmholtz equation reflection coefficient Visakhapatnam Port
下载PDF
Neural Network Approach to Response of Buildings Due to Earthquake Excitation
5
作者 Sayantan Chakraborty prashant kumar Swapan kumar Chakraborty 《International Journal of Geosciences》 2012年第3期630-639,共10页
The present article investigates the physical phenomena associated with the wave passage effect into a building considering the ground floor as the soft floor with the conformity of the up-to-date scenario of the cons... The present article investigates the physical phenomena associated with the wave passage effect into a building considering the ground floor as the soft floor with the conformity of the up-to-date scenario of the construction of high rise buildings, due to shear excitation of the base. The aim of the study is to analyse the post-earthquake situation of the building in respect to its health. With this vision, the ensuing problem on two-dimensional building models, non-incorporating soil-structure interaction, is being tackled by both analytical and neural network approaches. Computational results from both ends (of the approaches) show that the wave energy does not always propagate from the ground into the building, but for lower frequency range it sails to the building without any disturbances. However, for higher frequency range, the computational results show that the building experiences large “torsional” deformations, as a result the building may collapse. Finally, both the approaches maintain a good agreement among themselves. The present investigation may lead to a long way in contributing to better and more rational, simplified design criteria. 展开更多
关键词 NEURAL Network ANISOTROPIC Building SOFT Ground FLOOR
下载PDF
A Case Study in the Use of Capsaicin in the Treatment of Neuropathic Chest Wall Pain and Post-thoracotomy Intercostal Neuralgia
6
作者 Charles Roberts Leonard Morgan +2 位作者 Kanisha Hall prashant kumar Stacy J.Smith 《Open Journal of Anesthesiology》 2012年第4期99-101,共3页
Off label use of Quetenza? (capsaicin 8%) patch in relieving post-thoracotomy neuropathic pain proved temporarily effective, but to a degree indicating limited usefulness in a clinical setting.A 57 year-old male with ... Off label use of Quetenza? (capsaicin 8%) patch in relieving post-thoracotomy neuropathic pain proved temporarily effective, but to a degree indicating limited usefulness in a clinical setting.A 57 year-old male with chronic post-thoracotomy pain was treated with 8% capsaicin topically. Pre-procedure pain was rated as 8 on a 10 point scale, the 30 minute post procedure pain was reported as 2 - 3 on a 10 point scale. Neuralgia was completely resolved for the initial 48 hours post-procedure, then returned gradually over the next 5 days. Because pain transmission pathways are the same in post herpetic and post traumatic neuralgias, the use of 8% capsaicin merits additional study. 展开更多
关键词 Post-thoracotomy Neuralgia CAPSAICIN Qutenza^(█)
下载PDF
Spatio-temporal assessment of soil salinization utilizing remote sensing derivatives,and prediction modeling:Implications for sustainable development
7
作者 prashant kumar Prasoon Tiwari +1 位作者 Arkoprovo Biswas prashant kumar Srivastava 《Geoscience Frontiers》 SCIE CAS CSCD 2024年第6期22-36,共15页
This study aims to investigate the combined use of multi-sensor datasets(Landsat 4–5&8 OLI satellite imagery,spatial resolution=30 m)coupled with field studies to evaluate spatio-temporal dynamics of soil saliniz... This study aims to investigate the combined use of multi-sensor datasets(Landsat 4–5&8 OLI satellite imagery,spatial resolution=30 m)coupled with field studies to evaluate spatio-temporal dynamics of soil salinization along the coastal belt in West Bengal,India.This study assesses soil salinization by mapping the salinity and electrical conductivity of saturation extract(ECe)and utilizing spectral signatures for estimating soil salinity.The SI change(%)was analyzed(2021–1995),categorizing increases in salinity levels into 5%,10%,and 50%changes possibly due to salt encrustation on the soil layers.The land use land cover(LULC)change map(2021–1995)demonstrates that the study area is continuously evolving in terms of urbanization.Moreover,in the study area,soil salinity ranges from 0.03 ppt to 3.87 ppt,and ECe varies from 0.35 dSm^(-1)to 52.85 dSm^(-1).Additionally,vulnerable saline soil locations were further identified.Classification of soil salinity based on ECe reveals that 26%of samples fall into the nonsaline category,while the rest belong to the saline category.The Spectral signatures of the soil samples(n=19)acquired from FieldSpec hand spectrometer show significant absorption features around 1400,1900,and 2250 nm and indicate salt minerals.The results of reflectance spectroscopy were crossvalidated using X-ray fluorescence and scanning electron microscopy.This study also employed partial least square regression(PLSR)approach to predict ECe(r^(2)=0.79,RMSE=3.29)and salinity parameters(r^(2)=0.75,RMSE=0.51),suggesting PLSR applicability in monitoring salt-affected soils globally.This study’s conclusion emphasizes that remote sensing data and multivariate analysis can be crucial tools for mapping spatial variations and predicting soil salinity.It has also been concluded that saline groundwater used for irrigation and aqua-cultural activities exacerbates soil salinization.The study will help policymakers/farmers identify the salt degradation problem more effectively and adopt immediate mitigation measures. 展开更多
关键词 Hyperspectral remote sensing Scanning electron microscopy X-ray fluorescence Partial least square regression Soil salinity Salinity index
下载PDF
Urban heat mitigation by green and blue infrastructure:Drivers,effectiveness,and future needs
8
作者 prashant kumar Sisay E.Debele +26 位作者 Soheila Khalili Christos H.Halios Jeetendra Sahani Nasrin Aghamohammadi Maria de Fatima Andrade Maria Athanassiadou Kamaldeep Bhui Nerea Calvillo Shi-Jie Cao Frederic Coulon Jill L.Edmondson David Fletcher Edmilson Dias de Freitas Hai Guo Matthew C.Hort Madhusudan Katti Thomas Rodding Kjeldsen Steffen Lehmann Giuliano Maselli Locosselli Shelagh K.Malham Lidia Morawska Rajan Parajuli Christopher D.F.Rogers Runming Yao Fang Wang Jannis Wenk Laurence Jones 《The Innovation》 EI 2024年第2期145-166,共22页
The combination of urbanization and global warming leads to urban overheating and compounds the frequency and intensity of extreme heat events due to climate change.Yet,the risk of urban overheating can be mitigated b... The combination of urbanization and global warming leads to urban overheating and compounds the frequency and intensity of extreme heat events due to climate change.Yet,the risk of urban overheating can be mitigated by urban green-blue-grey infrastructure(GBGI),such as parks,wetlands,and engineered greening,which have the potential to effectively reduce summer air temperatures.Despite many reviews,the evidence bases on quantified GBGI cooling benefits remains partial and the practical recommendations for implementation are unclear.This systematic literature review synthesizes the evidence base for heat mitigation and related co-benefits,identifies knowledge gaps,and proposes recommendations for their implementation to maximize their benefits.After screening 27,486 papers,202 were reviewed,based on 51 GBGI types categorized under 10 main divisions.Certain GBGI(green walls,parks,street trees)have been well researched for their urban cooling capabilities.However,several other GBGI have received negligible(zoological garden,golf course,estuary)or minimal(private garden,allotment)attention.The most efficient air cooling was observed in botanical gardens(5.0±3.5℃),wetlands(4.9±3.2℃),green walls(4.1±4.2℃),street trees(3.8±3.1℃),and vegetated balconies(3.8±2.7℃).Under changing climate conditions(2070–2100)with consideration of RCP8.5,there is a shift in climate subtypes,either within the same climate zone(e.g.,Dfa to Dfb and Cfb to Cfa)or across other climate zones(e.g.,Dfb[continental warm-summer humid]to BSk[dry,cold semi-arid]and Cwa[temperate]to Am[tropical]).These shifts may result in lower efficiency for the current GBGI in the future.Given the importance of multiple services,it is crucial to balance their functionality,cooling performance,and other related co-benefits when planning for the future GBGI.This global GBGI heat mitigation inventory can assist policymakers and urban planners in prioritizing effective interventions to reduce the risk of urban overheating,filling research gaps,and promoting community resilience. 展开更多
关键词 ESTUARY walls EXTREME
原文传递
Artificial intelligence for geoscience:Progress,challenges,and perspectives
9
作者 Tianjie Zhao Sheng Wang +48 位作者 Chaojun Ouyang Min Chen Chenying Liu Jin Zhang Long Yu Fei Wang Yong Xie Jun Li Fang Wang Sabine Grunwald Bryan MWong Fan Zhang Zhen Qian Yongjun Xu Chengqing Yu Wei Han Tao Sun Zezhi Shao Tangwen Qian Zhao Chen Jiangyuan Zeng Huai Zhang Husi Letu Bing Zhang Li Wang Lei Luo Chong Shi Hongjun Su Hongsheng Zhang Shuai Yin Ni Huang Wei Zhao Nan Li Chaolei Zheng Yang Zhou Changping Huang Defeng Feng Qingsong Xu Yan Wu Danfeng Hong Zhenyu Wang Yinyi Lin Tangtang Zhang prashant kumar Antonio Plaza Jocelyn Chanussot Jiabao Zhang Jiancheng Shi Lizhe Wang 《The Innovation》 EI 2024年第5期136-160,135,共26页
This paper explores the evolution of geoscientific inquiry,tracing the progression from traditional physics-based models to modern data-driven approaches facilitated by significant advancements in artificial intellige... This paper explores the evolution of geoscientific inquiry,tracing the progression from traditional physics-based models to modern data-driven approaches facilitated by significant advancements in artificial intelligence(AI)and data collection techniques.Traditional models,which are grounded in physical and numerical frameworks,provide robust explanations by explicitly reconstructing underlying physical processes.However,their limitations in comprehensively capturing Earth’s complexities and uncertainties pose challenges in optimization and real-world applicability.In contrast,contemporary data-driven models,particularly those utilizing machine learning(ML)and deep learning(DL),leverage extensive geoscience data to glean insights without requiring exhaustive theoretical knowledge.ML techniques have shown promise in addressing Earth science-related questions.Nevertheless,challenges such as data scarcity,computational demands,data privacy concerns,and the“black-box”nature of AI models hinder their seamless integration into geoscience.The integration of physics-based and data-driven methodologies into hybrid models presents an alternative paradigm.These models,which incorporate domain knowledge to guide AI methodologies,demonstrate enhanced efficiency and performance with reduced training data requirements.This review provides a comprehensive overview of geoscientific research paradigms,emphasizing untapped opportunities at the intersection of advanced AI techniques and geoscience.It examines major methodologies,showcases advances in large-scale models,and discusses the challenges and prospects that will shape the future landscape of AI in geoscience.The paper outlines a dynamic field ripe with possibilities,poised to unlock new understandings of Earth’s complexities and further advance geoscience exploration. 展开更多
关键词 EARTH utilizing LANDSCAPE
原文传递
Impact of ionizers on prevention of airborne infection in classroom
10
作者 Chen Ren Fariborz Haghighat +2 位作者 Zhuangbo Feng prashant kumar Shi-Jie Cao 《Building Simulation》 SCIE EI CSCD 2023年第5期749-764,共16页
Infectious diseases(e.g.,coronavirus disease 2019)dramatically impact human life,economy and social development.Exploring the low-cost and energy-saving approaches is essential in removing infectious virus particles f... Infectious diseases(e.g.,coronavirus disease 2019)dramatically impact human life,economy and social development.Exploring the low-cost and energy-saving approaches is essential in removing infectious virus particles from indoors,such as in classrooms.The application of air purification devices,such as negative ion generators(ionizers),gains popularity because of the favorable removal capacity for particles and the low operation cost.However,small and portable ionizers have potential disadvantages in the removal efficiency owing to the limited horizontal diffusion of negative ions.This study aims to investigate the layout strategy(number and location)of ionizers based on the energy-efficient natural ventilation in the classroom to improve removal efficiency(negative ions to particles)and decrease infection risk.Three infected students were considered in the classroom.The simulations of negative ion and particle concentrations were performed and validated by the experiment.Results showed that as the number of ionizers was 4 and 5,the removal performance was largely improved by combining ionizer with natural ventilation.Compared with the scenario without an ionizer,the scenario with 5 ionizers largely increased the average removal efficiency from around 20%to 85%and decreased the average infection risk by 23%.The setup with 5 ionizers placed upstream of the classroom was determined as the optimal layout strategy,particularly when the location and number of the infected students were unknown.This work can provide a guideline for applying ionizers to public buildings when natural ventilation is used. 展开更多
关键词 CLASSROOM infection risk IONIZER negative ions removal efficiency
原文传递
TSKARNA-norm Adaption Based NLMS with Optimized Fractional Order PID Controller Gains for Voltage Power Quality
11
作者 prashant kumar Sabha Raj Arya Khyati D.Mistry 《Chinese Journal of Electrical Engineering》 EI CSCD 2023年第3期84-98,共15页
The operation of a dynamic voltage restorer(DVR)is studied using a three-phase voltage source converter(VSC)-based topology to alleviate voltage anomalies from a polluted supply voltage.The control algorithm used incl... The operation of a dynamic voltage restorer(DVR)is studied using a three-phase voltage source converter(VSC)-based topology to alleviate voltage anomalies from a polluted supply voltage.The control algorithm used included two components.The first is an adaptive Takagi-Sugeno-Kang(TSK)-based adaptive reweighted L1 norm adaption-based normalized least mean square(TSK-ARNA-NLMS)unit,which is proposed for the extraction of fundamental active and reactive components from the non-ideal supply and is further employed to generate the load reference voltage and switching pulse for the VSC.The step size was evaluated using the proposed TSK-ARNA-NLMS controller,and the TSK unit was optimized by integration with the marine predator algorithm(MPA)for a faster convergence rate.The second,a fractional-order PID controller(FOPID),was employed for AC-and DC-link voltage regulation and was approximated using the Oustaloup technique.The FOPID()PI Dγμprovides more freedom for tuning the settling time,rise time,and overshoot.The FOPID coefficients(Ki,Kd,Kp,γ,andμ)were optimized by employing an advanced ant lion optimization(ALO)meta-heuristics technique to minimize the performance index,namely,the integral time absolute error(ITAE)and assess the accuracy of controllers.The DVR performance was validated under dynamic-and steady-state conditions. 展开更多
关键词 Takagi-Sugeno-Kang(TSK) ARNA-NLMS FOPID-ALO unbalances gain optimization approximation Oustaloup technique
原文传递
Technical challenges in tackling regulatory concerns for urban atmospheric nanoparticles 被引量:3
12
作者 prashant kumar Alan Robins +1 位作者 Sotiris Vardoulakis Paul Quincey 《Particuology》 SCIE EI CAS CSCD 2011年第6期566-571,共6页
Recent Euro 5 and Euro 6 vehicle emission standards are the first ever initiative to control particles on a number basis at the source. Related standards are also desirable for ambient nanoparticles (taken in this ar... Recent Euro 5 and Euro 6 vehicle emission standards are the first ever initiative to control particles on a number basis at the source. Related standards are also desirable for ambient nanoparticles (taken in this article to be those below 300 rim) to protect against possible adverse effects on public health and the environment. However, there are a number of technical challenges that need to be tackled before developing a regulatory framework for atmospheric nanoparticles. Some of the challenges derive from a lack of standardisation of the key measurement parameters, including sampling, necessary for robust evaluation of particle number concentrations, especially in the context of insufficient knowledge of the physicochemical characteristics of emerging sources (i.e. bio-fuel derived and manufactured nanoparti- cles). Ideally, ambient concentrations of primary particles could be linked to primary particle emissions by use of nanoparticle dispersion models, and secondary nanoparticles using photochemical modeling tools. The limitations in these areas are discussed. Although there is inadequate information on the exact biological mechanism through which these particles cause harm, it is argued that this should not in itself delay the introduction of regulation. This article reviews the missing links between the existing knowledge of nanoparticle number concentrations and the advances required to tackle the technical challenges implied in developing regulations. 展开更多
关键词 Airborne and manufactured nanoparticles Particle number concentrations Size distributions Street canyons Ultrafine particles Vehicle emissions
原文传递
Tsc2 mutation induces renal tubular cell nonautonomous disease
13
作者 prashant kumar Fahad Zadjali +6 位作者 Ying Yao Daniel Johnson Brian Siroky Aristotelis Astrinidis Peter Vogel Kenneth W.Gross John J.Bissler 《Genes & Diseases》 SCIE 2022年第1期187-200,共14页
TSC renal cystic disease is poorly understood and has no approved treatment.In a new principal cell-targeted murine model of Tsc cystic disease,the renal cystic epithelium is mostly composed of type A intercalated cel... TSC renal cystic disease is poorly understood and has no approved treatment.In a new principal cell-targeted murine model of Tsc cystic disease,the renal cystic epithelium is mostly composed of type A intercalated cells with an intact Tsc2 gene confirmed by sequencing,although these cells exhibit a Tsc-mutant disease phenotype.We used a newly derived targeted murine model in lineage tracing and extracellular vesicle(EV)characterization experiments and a cell culture model in EV characterization and cellular induction experiments to understand TSC cystogenesis.Using lineage tracing experiments,we found principal cells undergo clonal expansion but contribute very few cells to the cyst.We determined that cystic kidneys contain more interstitial EVs than noncystic kidneys,excrete fewer EVs in urine,and contain EVs in cyst fluid.Moreover,the loss of Tsc2 gene in EV-producing cells greatly changes the effect of EVs on renal tubular epithelium,such that the epithelium develops increased secretory and proliferative pathway activity.We demonstate that the mTORC1 pathway activity is independent form the EV production,and that the EV effects for a single cell line can vary significantly.TSC cystogenesis involves significant contribution from genetically intact cells conscripted to the mutant phenotype by mutant cell derived EVs. 展开更多
关键词 Cell nonautonomous trait Polycystic kidney disease Renalcystogenesis Tuberous sclerosis complex
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部