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A model for virtual network embedding across multiple infrastructure providers using genetic algorithm

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Science China(Information Sciences) 2017年第4期60卷 101-112页

作者： Isha PATHAK deo Prakash VIDYARTHI School of Computer and Systems Sciences Jawaharlal Nehru University

Network virtualization is an important aspect in cloud computing, where network is assumed to be consisting of infinite amount of nodes and links. The substrate network(physical network), has limited capacity and so virtual network embedding on the substrate network becomes a problem. Virtual network embedding is a computationally hard problem, considering various constraints on nodes and links. The proposed work applies Genetic Algorithm for the virtual network embedding problem for mapping multiple virtual network requests on infrastructure providers managing multiple substrate networks. Performance evaluation, through simulations,indicates that the proposed model preforms better for the performance metrics such as infrastructure provider revenue, acceptance ratio and node and link utilization in comparison to few other contemporary mapping models.

关键词： network virtualization virtual network embedding substrate network NP-hard genetic algorithm

Comparison of two-and three-dimensional modeling of invert trap for sewer solid management

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Particuology 2008年第3期6卷 176-184页

作者： Tsewang Thinglas deo Raj Kaushal Civil Engineering Department IIT DelhiHauz KhasNew Delhi 110016India

In the present study, five different invert trap configurations （rectangular with and without lids on both sides; trapezoidal, trapezoidal with rectangular base and rectangular with trapezoidal base with lids on both sides） were simulated for both two-dimensional （2D） and three-dimensional （3D） flow conditions for three sediment types （sand, styrocell and plastic beads） at six flow rates （0.35, 0.70, 1.05, 1.35, 4.55 and 9.95 L/s） for each trap. Computational fluid dynamics （CFD）-based modeling using FLUENT software with Renormalization Group （RNG） k-e model along with discrete phase model （DPM） were used in the simulations. A hexagonal/tetrahedral and map-type non-uniform grid was chosen to discretize the entire computational domain and a control volume finite difference method was used to solve the governing equations. The flow rates selected in the present study cover the entire range of flow rate expected for dry weather and monsoon. The simulation is capable of differentiating between 2D and 3D modeling of particle trajectories, the effects of flow rate and trap geometry on flow patterns developed in the trap. The sediment retention ratio for 2D is higher than that for 3D modeling for all flow conditions, particle types and model geometry due to inclusion of lateral effects in 3D modeling. The invert trap having rectangular shape with trapezoidal base is found to be the most efficient configuration in both 2D and 3D modeling.

关键词： CFD modeling 2D 3D Invert trap Sediment trapping Urban drainage

Three-dimensional computational fluid dynamics （volume of fluid） modelling coupled with a stochastic discrete phase model for the performance analysis of an invert trap experimentally validated using field sewer solids

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Particuology 2017年第4期15卷 98-111页

作者： Mohammad Mohsin deo Raj Kaushal Civil Engineering Department Indian Institute of Technology Delhi New Delhi India

Invert traps are used to trap sewer solids flowing into a sewer drainage system, The performance of the invert trap in an open rectangular channel was experimentally and numerically analysed using field sewer solids collected from a sewer drain. Experiments showed that the free water surface rises over the central opening （slot） of the invert trap, which reduces the velocity near the slot and allows more sediment to be trapped in comparison with the case for the fixed-lid model （assuming closed conduit flow with a shear-free top wall） used by earlier investigators. This phenomenon cannot be modelled using a closed conduit model as no extra space is provided for the fluctuation of the water surface, whereas this space is provided in the volume of fluid （VOF） model in the form of air space in ANSYS Fluent 14.0 software. Additionally, the zero atmospheric pressure at the free water surface cannot be modelled in a fixed-lid model. In the present study, experimental trap efflciencies of the invert trap using field sewer solids were fairly validated using a three-dimensional computational fluid dynamics model （VOF model） coupled with a stochastic discrete phase model. The flow field （i.e., velocities） predicted by the VOF model were compared with experimental velocities obtained employing particle image velocimetry. The water surface profile above the invert trap predicted by the VOF model was found to be in good agreement with the experimentally measured profile. The present study thus showed that the VOF model can be used with the stochastic discrete phase model to well predict the performance of invert traps.

关键词： Computational fluid dynamics mode Invert trap Sedimentation Trap efficiency Retention ratio Volume of fluid model

Upconversion nanoparticles:Recent strategies and mechanism based applications

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Journal of Rare Earths 2022年第9期40卷 1343-1359,I0001页

作者： neha Dubey Sudeshna Chandra Department of Chemistry Sunandan Divatia School of ScienceSVKM's NMIMS(Deemed to-be)UniversityVile Parle(West)Mumbai400056India

Upconversion nanoparticles(UCNPs)doped with lanthanides can convert near-infrared excitation into UV and visible *** of their relatively high emission efficiency,UCNPs are appealing materials for use in a variety of *** are known for low auto-fluorescence,excellent chemical and thermal photo-stability,deep tissue penetration,exceptional biocompatibility,low toxicity,color purity,and ease of surface *** this review,we explain a few recent strategies to boost the efficiency and luminescence of upconversion nanoparticles and minimize quenching by fabricating them as core/shell,nanofibers,or heavily doped *** of UCNPs in drug delivery,Photodynamic therapy(PDT),biosensors,bioimaging,and optogenetics are also discussed along with their mechanism of *** motivation for this review is to understand the working mechanism of UCNPs and their applications in various fields.

关键词： Luminescence Upconversion nanoparticles Optical imaging Mechanism Applications Rare earths

Significance of including lid thickness and particle shape factor in numerical modeling for prediction of particle trap efficiency of invert trap

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Water Science and Engineering 2024年第2期17卷 166-176页

作者： Salman Beg deo Raj Kaushal Department of Civil Engineering Indian Institute of Technology DelhiNew Delhi 110016India

Sediment accumulation on the bed of open sewers and drains reduces hydraulic efficiency and can cause localized *** invert traps installed underneath the bed of open sewers and drains can eliminate sediment build-up by catching sediment *** three-dimensional(3D)computational studies have examined the particle trapping performance of invert traps of different shapes and depths under varied sediment and flow conditions,considering particles as *** two-dimensional and 3D numerical modeling,researchers assumed the lid geometry to be a thin line and a plane,*** this 3D numerical study,the particle trapping efficiency of a slotted irregular hexagonal invert trap fitted at the flume bottom was examined by incorporating the particle shape factor of non-spherical sewage solid particles and the thicknesses of upstream and downstream lids over the trap in the discrete phase model of the ANSYS Fluent 2020 R1 *** volume of fluid(VOF)and the realizable k-turbulence models were used to predict the velocity *** two-dimensional particle image velocimetry(PIV)was used to measure the velocity field inside the invert *** results showed that the thicknesses of upstream and downstream lids affected the velocity field and turbulent kinetic energy at all flow *** joint impact of the particle shape factor and lid thickness on the trap efficiency was *** both the lid thickness and particle shape factor were considered in the numerical modeling,trap efficiencies were underestimated,with relative errors of-8.66%to-0.65%in comparison to the experimental values of Mohsin and Kaushal(2017).They were also lower than the values predicted by Mohsin and Kaushal(2017),which showed an overall overestimation with errors of-2.3%to 17.4%.

关键词： Invert trap Lid thickness Particle image velocimetry Particle shape factor Turbulent kinetic energy Scanning electron microscope

3D CFD validation of invert trap efficiency for sewer solid management using VOF model

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Water Science and Engineering 2016年第2期9卷 106-114页

作者： Mohammad Mohsin deo Raj Kaushal Civil Engineering Department Indian Institute of Technology Delhi

Earlier investigators have numerically carried out performance analysis of the invert trap fitted in an open channel using the stochastic discrete phase model(DPM) by assuming the open channel flow to be closed conduit flow under pressure and assuming zero shear stress at the top *** is known as the fixed lid *** assuming the top wall to be a shear free wall,they have been able to show that the velocity distribution looks similar to that of an open channel flow with zero velocity at the bottom and maximum velocity at the top,representing the free water surface,but no information has been provided for the pressure at the free water *** of this assumption,the validation of the model in predicting the trap efficiency has performed significantly *** addition,the free water surface subject to zero gauge pressure cannot be modeled using the fixed lid model because there is no provision of extra space in the form of air space for the fluctuating part of the water surface *** ***,be modeled using the volume of fluid(VOF) model because the VOF model is the appropriate model for open channel or free surface ***,in the present study,three-dimensional(3D) computational fluid dynamics(CFD) modeling with the VOF model,which considers open channel flow with a free water surface,along with the stochastic *** used to model the trap efficiency of an invert trap fitted in an open rectangular *** governing mathematical flow equations of the VOF model were solved using the ANSYS Fluent 14.0 software,reproducing the experimental conditions *** results show that the 3D CFD predictions using the VOF model closely fit the experimental data for glass bead particles.

关键词： Computational fluid dynamics (CFD) Sediment deposition Trap efficiency Invert trap Volume of fluid (VOF) model

Insights into the interface of NiCo_(2)O_(4) spinel/LaCoO_(3) perovskite nano-composite for CO and soot oxidation

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Journal of Environmental Sciences 2024年第4期138卷 339-349页

作者： neha Harshita Singh Satya Vir Singh Department of Chemical Engineering Indian Institute of Technology(BHU)Varanasi221005India Department of Botany Institute of ScienceBanaras Hindu UniversityVaranasi221005India

In the quest for the development of thermally stable,highly active and low-cost catalysts for use in catalyzed diesel particulate filter,nano-composites are new areas of ***,we reported the easy synthesis of spinel NiCo_(2)O_(4)/perovskite LaCoO_(3) nano-composite,and its individual oxides NiCo_(2)O_(4)and LaCoO_(3) for *** detailed insights into the physio-chemical characteristics of formed NiCo_(2)O_(4)/LaCoO_(3) nano-composite were done based on various characterization analysis such as X-ray diffraction(XRD),Fourier transform infrared(FT-IR),N_(2) physiosorption,scanning electron microscopy-energy dispersive spectroscopy(SEM-EDX),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).The characterization analysis of NiCo_(2)O_(4)/LaCoO_(3) revealed the successful formation of a chemical interface possessing strong interfacial interaction,resulting in desirable physicochemical characteristics such as small crystallite size,abundant mesoporosity,high specific surface area and activation of surface lattice *** to the desirable characteristics,the activity results over NiCo_(2)O_(4)/LaCoO_(3) nano-composite showed the excellent CO oxidation performance and high soot oxidation activity,recyclability and thermal *** work mainly attempts to emphasize the effectiveness of the facile,inexpensive and conventionally used precipitation method for the successful formation of highly efficient nano-composites.

关键词： LaCoO_(3) NiCo_(2)O_(4) Spinel/perovskite CO oxidation Soot oxidation Chemical interface

Healthcare providers’perspectives on factors influencing their critical care decision-making during the COVID-19 pandemic:An international pilot survey

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World Journal of Critical Care Medicine 2025年第1期14卷 100-110页

作者： Sonali Vadi neha Sanwalka Pramod Thaker Department of Critical Care Medicine Kokilaben Dhirubhai Ambani Hospital and Medical Research InstituteMumbai 400053MahārāshtraIndia Department of Statistics HCJMRIJehangir HospitalPune 411001MahārāshtraIndia Medical Ethics Fellowship Harvard Medical SchoolBostonMA 02138United States

BACKGROUND Understanding a patient's clinical status and setting priorities for their care are two aspects of the constantly changing process of clinical *** analytical technique that can be helpful in uncertain situations is clinical *** must deal with contradictory information,lack of time to make decisions,and long-term factors when emergencies *** To examine the ethical issues healthcare professionals faced during the coronavirus disease 2019(COVID-19)pandemic and the factors affecting clinical *** This pilot study,which means it was a preliminary investigation to gather information and test the feasibility of a larger investigation was conducted over 6 months and we invited responses from clinicians worldwide who managed patients with *** survey focused on topics related to their professional roles and personal *** examined five core areas influencing critical care decision-making:Patients'personal factors,family-related factors,informed consent,communication and media,and hospital administrative policies on clinical *** collected data were analyzed using theχ2 test for categorical *** A total of 102 clinicians from 23 specialties and 17 countries responded to the *** was a significant factor in treatment planning(n=88)and ventilator access(n=78).Sex had no bearing on how decisions were *** doctors reported maintaining patient confidentiality regarding privacy and informed *** 50%of clinicians reported a moderate influence of clinical work,with many citing it as one of the most important factors affecting their health and *** from developing countries had a significantly higher score for considering a patient's financial status when creating a treatment plan than their counterparts from developed *** personal experiences,some respondents noted that treatment plans and preferences change

关键词： Survey Clinical decision-making COVID-19 pandemic

Intelligent Multilevel Node Authentication in Mobile Computing Using Clone Node

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Computers, Materials & Continua 2022年第3期70卷 5269-5284页

作者： neha Malhotra Manju Bala I.K.Gujral Punjab Technical University Kapurthala144603India Lovely Professional University Phagwara144411India Khalsa College of Engineering and Technology Amritsar143001India

Nodes in a mobile computing system are vulnerable to clone attacks due to their *** such attacks,an adversary accesses a few network nodes,generates replication,then inserts this replication into the network,potentially resulting in numerous internal network *** existing techniques use a central base station,which introduces several difficulties into the system due to the network’s reliance on a single point,while other ways generate more overhead while jeopardising network *** this research,an intelligent double hashing-based clone node identification scheme was used,which reduces communication and memory costs while performing the clone detection *** approach works in two stages:in the first,the network is deployed using an intelligent double hashing procedure to avoid any network collisions and then in the second,the clone node identification procedure searches for any clone node in the *** first phase verifies the node prior to network deployment,and then,whenever a node wants to interact,it executes the second level of ***-to-end delay,which is bound to increase owing to the injection of clone nodes,and packet loss,which is reduced by the double hashing technique,were used to evaluate the performance of the aforementioned approach.

关键词： Node authentication clone node mobile computing double hashing fault tolerance