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Journal of Advanced Dielectrics 2018年第3期8卷 64-78页

作者： Chetna Tyagi ambika devi Department of Applied Sciences The NorthCap University Gurugram 122017 HaryanaIndia

The important enhancement in the structural,dielectric and optical properties of pure polymer and CdSe incorporated polyvinyl pyrrolidone has been reported in this *** surface morphology of CdSe/PVP nanocomposite film is studied by using scanning electron microscopy(SEM).The chemical composition of different elements has been reported using energy dispersive X-ray(EDX)*** structure of polymer nanocomposite is determined with the help of X-ray diffraction(XRD)spectrum and is observed to be *** size,intercrystalline separation,interplanner spacing,lattice parameters,strain and dislocation factors are calculated using XRD *** transform infrared spectroscopy(FTIR)and Photoluminescence(PL)analysis have been studied in order to check the possible interaction between CdSe quantum dots and polyvinyl pyrrolidone(PVP)*** ac conductivity of CdSe/PVP nanocomposite is found to be higher as compared to pure *** highest value of conductivity observed at 60203 Hz and at 523 K is found to be 3:72105 Sm*** study of dielectric constant,dielectric losses,dissipation factor,electric modulus and impedance has been *** semi-circles in impedance measurement for both materials show the bulk electrical properties that result in single relaxation process in CdSe/PVP nanocomposite.

关键词： Nanocomposites activation energy FTIR refractive index

Enhanced Clustering Based OSN Privacy Preservation to Ensure k-Anonymity, t-Closeness, l-Diversity, and Balanced Privacy Utility

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Computers, Materials & Continua 2023年第4期75卷 2171-2190页

作者： Rupali Gangarde Amit Sharma ambika Pawar Department of CSE Lovely Professional UniversityPhagwara144411India Department of CSE Symbiosis Institute of Technology(SIT)Affiliated to Symbiosis International(Deemed University)Pune412115India School of Computer Applications Lovely Professional UniversityPhagwara144411India Learning&Development Persistent UniversityPersistent SystemsPune411057India

Online Social Networks (OSN) sites allow end-users to share agreat deal of information, which may also contain sensitive information,that may be subject to commercial or non-commercial privacy attacks. Asa result, guaranteeing various levels of privacy is critical while publishingdata by OSNs. The clustering-based solutions proved an effective mechanismto achieve the privacy notions in OSNs. But fixed clustering limits theperformance and scalability. Data utility degrades with increased privacy,so balancing the privacy utility trade-off is an open research issue. Theresearch has proposed a novel privacy preservation model using the enhancedclustering mechanism to overcome this issue. The proposed model includesphases like pre-processing, enhanced clustering, and ensuring privacy *** enhanced clustering algorithm is the second phase where authorsmodified the existing fixed k-means clustering using the threshold *** threshold value is determined based on the supplied OSN data of edges,nodes, and user attributes. Clusters are k-anonymized with multiple graphproperties by a novel one-pass algorithm. After achieving the k-anonymityof clusters, optimization was performed to achieve all privacy models, suchas k-anonymity, t-closeness, and l-diversity. The proposed privacy frameworkachieves privacy of all three network components, i.e., link, node, and userattributes, with improved utility. The authors compare the proposed techniqueto underlying methods using OSN Yelp and Facebook datasets. The proposedapproach outperformed the underlying state of art methods for Degree ofAnonymization, computational efficiency, and information loss.

关键词： Enhanced clustering online social network k-anonymity t-closeness l-diversity privacy preservation

Spatio-temporal variation of trace elements distributed over surface water of Upper Ganga River Basin in Western Himalayan Region

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Journal of Mountain Science 2023年第1期20卷 145-162页

作者： Deepika DIMRI ambika KUMAR DeepakKumar MISHRA Archana SHARMA Doon University Dehradun248012India Bhagalpur National College Bhagalpur812007India

The rivers draining from the Himalayan range distribute enormous amount of fresh water to the people living in downstream *** metals flowed with river water can lead to serious impact on ecological system and human ***,the documentation on trace elements of Himalayan rivers is inadequately *** current study deals with the spatial and temporal variability of the major and trace elements of Ganga river water in epirhithron,metarhithron and hyporhithron zone belonging to Himalayan *** samples from nineteen monitoring locations were collected in pre-monsoon(May-June),monsoon(AugustSeptember)and post-monsoon(December)seasons and subjected to be assessed for 20 elements(Ag,Al,Ba,Cd,Ca,Cr,Cu,Fe,Ga,K,Mn,Mg,Na,Ni,Pb,Sr,Th,U,Zn,and Zr)using ICP-OES(Inductively Coupled Plasma-Optical Emission Spectrometer).Different water pollution indexes such as HPI(Heavy Metal Pollution Index),MI(Metal Index)and PI(Pollution Index)were used to describe current water quality status at each monitoring station under particular classified ecological *** studied stations in hyporhithron zone had the value of Metal Index(MI>1),indicating threshold of ***,the highest values of HPI in hyporhithron zone correspond to poor water quality *** with poor water quality were also found to be contaminated as per the Pollution Index(PI),exhibiting high concentrations for element(Fe).However,the epirhithron and metarhithron zone in Himalayan segment showed excellent water quality mainly contributed from natural *** Analysis(CA)and Principal Component Analysis(PCA)were applied to identify the main influential sources for Ganga river water *** Kriging interpolation method was also applied to prepare spatial distribution map of computed indexes(HPI,MI,and PI).With the help of index of local Moran’s I(LMI),identified spatial clusters and spatial outliers revealed the elevated concentration of most elements in hyporhithr

关键词： Trace elements Spatial variation Temporal variation Surface water Ganga River Basin ICP-OES

Deep insights into the advancements and applications of perovskite based photovoltaic cells

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Journal of Energy Chemistry 2018年第3期27卷 753-763页

作者： Chandni devi Rajesh Mehra Electronics and Communication Department NITTTR

The organometal halide perovskite materials have a blend of surprising optoelectronic properties, for example high value of absorption coefficient and abrupt optical retention edge, lifetime, long charge carrier diffusion length and many more. Brought in conjunction with the capacity for manufacturing at low temperature, likewise from the solution, devices based on perovskite, particularly solar cells have been contemplated seriously with striking advancements in performance, in the course of recent years. The amalgamation of minimal effort, high efficiency and extra applications gives incredible potential to commercialization of these cells. The applications and performance of perovskite cells frequently relate with the structures of the device. Numerous creative structures of the devices were produced, targeting for vast scale manufacture, diminishing creation cost, upgrading the PCE and subsequently expanding the prospective for future applications. This paper outlines the various advanced structures of PSC, challenges confronted by these PSCs and their future perspectives. The commercial applications of PSC are additionally talked about in this paper.

关键词： Solar cells Flexibility ETM Perovskite HTM Structures

Experimental Performance Analysis of a Corrugation Type Solar Air Heater(CTSAH)

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Energy Engineering 2022年第4期119卷 1483-1499页

作者： Aravindh Madhavankutty ambika Aarjab Ghimire Sreekumar Appukuttan Ministry of New and Renewable Energy Government of IndiaNew Delhi110003India Department of Green Energy Technology Madanjeet School of Green Energy TechnologiesPondicherry UniversityPuducherry605014India

This paper explains the experimental performance evaluation of a Corrugated Type Solar Air Heater(CTSAH)for understanding its performance in a humid tropical climatic condition in Puducherry,*** helps in understanding its effectiveness in using it for drying application of products like seafood,*** were conducted at different mass flow rates and their effect on the heat gain,efficiency,friction factor heat transfer,etc.,was *** were carried out at different mass flow rates,i.e.,M1=0.06 kg/s,M2=0.14 kg/s,M3=0.17 kg/s,M4=0.25 kg/s,M5=0.3 kg/s,and were conducted from 11:00 h to 14:00 *** air inlet&air temperature is found to be at an average of 40°C whereas the incident solar radiation is at an average of 795 W/*** results show that the optimum performance of the CTSAH is in the mass flow rate range of 0.14–0.25(kg/s).Also,the calculated useful heat produced,convective heat transfer coefficients,effective efficiency,optical efficiency provides knowledge on the potential use of the air heater.

关键词： Solar air heater performance analysis efficiency solar thermal

NONCONSTANT PREY HARVESTING IN RATIO-DEPENDENT PREDATOR-PREY SYSTEM INCORPORATING A CONSTANT PREY REFUGE

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International Journal of Biomathematics 2012年第2期5卷 85-104页

作者： SAPNA devi DST Centre for Interdisciplinary Mathematical Sciences Banaras Hindu University Varanasi-221005 India

This paper deals with the problem of nonconstant harvesting of prey in a ratio-dependent predator-prey system incorporating a constant prey refuge. Here we use the reasonable catch-rate function instead of usual catch-per-unit-effort hypothesis. The existence, as well as the stability of possible equilibria, is carried out. Bionomic equilibrium of the system is determined and optimal harvest policy is studied with the help of Pontryagin＇s maximum principle. The key results developed in this paper are illustrated using numer- ical simulations. Our results indicate that dynamic behavior of the system very much depends on the prey refuge parameter and increasing amount of refuge could increase prey density and may lead to the extinction of predator population density.

关键词： Predator-prey prey refuge taxation ratio-dependent stability bionomic equilibrium harvesting optimal equilibrium.

Nonlinear time series analysis of the light curves from the black hole system GRS1915+105

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Research in Astronomy and Astrophysics 2011年第1期11卷 71-90页

作者： K.P.Harikrishnan Ranjeev Misra G.ambika Department of Physics The Cochin College Inter University Centre for Astronomy and Astrophysics Indian Institute of Science Education and Research

GRS 1915＋105 is a prominent black hole system exhibiting variability over a wide range of time scales and its observed light curves have been classified into 12 temporal states. Here we undertake a complete analysis of these light curves from all the states using various quantifiers from nonlinear time series analysis, such as the correlation dimension （D2）, the correlation entropy （K2）, singular value decomposition （SVD） and the multifractal spectrum （f（α） spectrum）. An important aspect of our analysis is that, for estimating these quantifiers, we use algorithmic schemes which we have recently proposed and successfully tested on synthetic as well as practical time series from various fields. Though the schemes are based on the conventional delay embedding technique, they are automated so that the above quantitative measures can be computed using conditions prescribed by the algorithm and without any intermediate subjective analysis. We show that nearly half of the 12 temporal states exhibit deviation from randomness and their complex temporal behavior could be approximated by a few （three or four） coupled ordinary nonlinear differential equations. These results could be important for a better understanding of the processes that generate the light curves and hence for modeling the temporal behavior of such complex systems. To our knowledge, this is the first complete analysis of an astrophysical object （let alone a black hole system） using various techniques from nonlinear dynamics.

关键词： accretion accretion disks -- X-rays: binaries

Plant diversity, population structure, and regeneration status in disturbed tropical forests in Assam, northeast India

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Journal of Forestry Research 2013年第4期24卷 715-720页

作者： Gitamani Dutta Ashalata devi Department of Environmental Science Tezpur University

We investigated the plant population structure and the phy- tosociological and regeneration status in two disturbed tropical forests in Assam Province, the Hojai Reserve Forest and Kumorakata Reserve Forest. A total of 166 species （80 trees, 20 shrubs and 66 herbs） of 136 genera and 63 families were recorded in both study sites. The disturbance index at the two sites, Kumorakata Reserve Forest and Hojai Reserve Forest, were recorded at 11.4% and 3.70% respectively. Reverse J-shaped population curve and exploitation of tree species in higher girth classes were recorded at both study sites. In the girth classes （10-30 cm, 30-60 cm, 60-90 cm and 90-120 cm in size） the percentage of cut stump density was higher than the percentage of individual living trees. The 18% （Kumorakata Reserve Forest） and 7% （Hojai Reserve Forest） spe- cies were recorded as not regenerating. Illegal felling and over-exploitation of forest resources may lead to species-specific changes in the population structure and can alter the future structure and composi- tion of the forests.

关键词： plant diversity regeneration disturbance population struc-ture Assam India

An application of blended amendments in monsoon rice field

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Ecological Processes 2017年第1期6卷 373-380页

作者： Madhumita Ghosh Ashalata devi Department of Environmental Science Tezpur UniversityP.O-784028 NapaamIndia

Introduction:Rice is the main food crop of the world,and the cultivation of rice crop during the monsoon season is hard due to the rain-induced *** from this,farmers in north-eastern regions of India often implement improper crop management leading to poor ***,the development of suitable management practices under improved varieties of rice become essential for increasing rice productivity,improving soil quality status and reducing methane ***:The aim of the study was to investigate the variation in soil properties,crop growth and methane emission under the application of an inorganic fertiliser as well as its mixtures with both inorganic and plant *** such an attempt,a field-based experiment was conducted with the rice variety Chandrama during 2015 in slightly acidic soil having sandy loam *** amendments,*** and NPK,blended separately with magnesium sulphate,fresh neem(Azadirechta indica)leaves,used tea(Camellia sinensis ***)leaves,and fresh karanj(Pongamia glabra)leaves were used for the study with four replications ***:Application of NPK separately with the leaves of neem,tea and karanj separately at the onset of monsoon season markedly affected the soil porosity and the water-holding capacity of the ***,in comparison with sole NPK fertilisation,a significance increase in soil organic matter accumulation(2.48±0.10%)was seen only for karanjblended NPK while magnesium sulphate-blended NPK showed the lowest methane emission(0.30±0.01 mg/m2/h).The rice plants grown on karanj-blended NPK soil showed the highest yield(0.560±0.01 kg/m2)among the five ***:It was found that only the karanj leaves blended NPK could significantly improve the soil organic matter and increase rice yield without intensifying methane emission,while magnesium sulphate blended with NPK could significantly reduce methane emission in the flooded rice paddy soil at 0.5 t/ha application level but

关键词： Inorganic fertiliser Leaves of plants Soil properties Rice yield Methane emission

An Optimized Transfer Learning Model Based Kidney Stone Classification

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Computer Systems Science & Engineering 2023年第2期44卷 1387-1395页

作者： S.devi Mahalakshmi Department of Computer Science and Engineering Mepco Schlenk Engineering CollegeSivakasi626005TamilnaduIndia

The kidney is an important organ of humans to purify the *** healthy function of the kidney is always essential to balance the salt,potassium and pH levels in the ***,the failure of kidneys happens easily to human beings due to their lifestyle,eating habits and diabetes *** pre-diction of kidney stones is compulsory for timely *** processing-based diagnosis approaches provide a greater success rate than other detection *** this work,proposed a kidney stone classiﬁcation method based on optimized Transfer Learning(TL).The Deep Convolutional Neural Network(DCNN)models of DenseNet169,MobileNetv2 and GoogleNet applied for clas-siﬁ*** combined classiﬁcation results are processed by ensemble learning to increase classiﬁcation *** hyperparameters of the DCNN model are adjusted by the metaheuristic algorithm of Gorilla Troops Optimizer(GTO).The proposed TL model outperforms in terms of all the parameters compared to other DCNN models.

关键词： DCNN GTO kidney stone transfer learning