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Structural and optical properties of CZTS nanoparticles prepared by a colloidal process

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Rare Metals 2021年第9期40卷 2602-2609页

作者： R.Aruna-devi M.Latha S.Velumani JoséÁlvaro chávez-Carvayar Program on Nanoscience and Nanotechnology CINVESTAV-IPNSan Pedro Zacatenco07360 Mexico CityMexico CIICAp-UAEM Av.Universidad 1001.Col.Chamilpa62209 CuernavacaMorelosMexico Department of Electrical Engineering(SEES) CINVESTAV-IPNSan Pedro Zacatenco07360 Mexico CityMexico Instituto de Investigaciones en Materiales UNAM04510 Mexico CityMexico

This research presents the influence of copper(Cu) concentration on the properties of copper zinc tin sulfide(CZTS) nanoparticles(NPs) synthesized by a colloidal method, employing oleylamine as an organic solvent. From the structural analysis, a pure phase of CZTS was obtained at an optimized molar ratio of 1.8:1.1:1:4,and secondary phases were observed as the Cu concentration increased. The increment of the NPs size from 15 to50 nm was noticed as a function of Cu ***, the optical bandgap energy was tuned from1.35 to 1.68 eV with respect to Cu concentration. The sample synthesized at the molar ratio of 1.8:1.1:1:4 showed a pure phase CZTS with desired elemental composition and bandgap. Furthermore, CZTS thin films were prepared by a doctor-blade method using synthesized NPs followed by annealing under a sulfur/nitrogen atmosphere. The annealed CZTS film showed a significant improvement in the morphological, electrical and optoelectronic ***, the annealed CZTS film can be efficiently used as an absorber layer in low-cost thin film solar cells.

关键词： CZTS Copper concentration Nanoparticles Thin film Annealing

Video Recommendation System Using Machine-Learning Techniques

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Journal of Harbin Institute of Technology(New Series) 2024年第4期31卷 24-33页

作者： Meesala Sravani ch Vidyadhari S Anjali devi Department of Computer Science and Engineering GMR Institute of TechnologyRajam 532127Andhra PradeshIndia Department of Information Technology Gokaraju Rangaraju Institute of Engineering and TechnologyKukatpallyHydarabad 500090TelanganaIndia Department of Computer Science and Engineering Koneru Lakshmaiah Education FoundationVaddeswaramGuntur 522302Andhra PradeshIndia

In the realm of contemporary artificial intelligence,machine learning enables automation,allowing systems to naturally acquire and enhance their capabilities through *** this cycle,Video recommendation is finished by utilizing machine learning strategies.A suggestion framework is an interaction of data sifting framework,which is utilized to foresee the“rating”or“inclination”given by the different *** expectation depends on past evaluations,history,interest,IMDB rating,and so *** can be carried out by utilizing collective and substance-based separating approaches which utilize the data given by the different clients,examine them,and afterward suggest the video that suits the client at that specific *** required datasets for the video are taken from *** recommender framework is executed by utilizing Python Programming *** building this video recommender framework,two calculations are utilized,for example,K-implies Clustering and KNN grouping.K-implies is one of the unaided AI calculations and the fundamental goal is to bunch comparable sort of information focuses together and discover the *** that K-implies searches for a steady‘k'of bunches in a dataset.A group is an assortment of information focuses collected due to specific similitudes.K-Nearest Neighbor is an administered learning calculation utilized for characterization,with the given information;KNN can group new information by examination of the‘k'number of the closest information *** last qualities acquired are through bunching qualities and root mean squared mistake,by using this algorithm we can recommend videos more appropriately based on user previous records and ratings.

关键词： video recommendation system KNN algorithms collaborative filtering content⁃based filtering classification algorithms artificial intelligence

Kinetic Alfven Waves Excited by Cometary Newborn Ions with Large Perpendicular Energies

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Plasma Science and Technology 2011年第2期13卷 135-139页

作者： George SAMUEL devi E SAVITHRI Venugopal chANDU School of Pure and Applied Physics Mahatma Gandhi University

Stability of the kinetic Alfven wave in a plasma of hydrogen, oxygen and electrons is studied. Each species is modeled by drifting ring distributions in the direction parallel to the magnetic field, while in the perpendicular direction the distribution is simulated with a loss cone type distribution obtained through the subtraction of two Maxwellian distributions with different temperatures. It is found that for frequencies ω＊〈 ωch with ω＊ and ωch the Doppler shifted and hydrogen ion gyro-frequencies, respectively, the growth rate of the kinetic Alfven wave increases with the increase in propagation angles and density of oxygen ions. On the other hand, for frequencies ω＊〈 ωco with ωco the oxygen ion gyro-frequency the growth rate is independent of the oxygen ion density.

关键词： kinetic Alfven wave stability multi-ion cometary plasma

Hybrid Optimisation with Black Hole Algorithm for Improving Network Lifespan

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Intelligent Automation & Soft Computing 2023年第2期35卷 1873-1887页

作者： S.Siamala devi chandrakala Kuruba Yunyoung Nam Mohamed Abouhawwash Department of Computer Science and Engineering Sri Krishna College of TechnologyCoimbatore641042India Department of Computer Science and Engineering Vignan Nirula Institute of Technology and ScienceGuntur522009India Department of Computer Science and Engineering Soonchunhyang UniversityAsan31538Korea Department of Mathematics Faculty of ScienceMansoura UniversityMansoura35516Egypt Department of Computational Mathematics Scienceand Engineering(CMSE)Michigan State UniversityEast LansingMI48824USA

Wireless sensor networks(WSNs)are projected to have a wide range of applications in the *** fundamental problem with WSN is that it has aﬁnite *** a network is a common strategy for increasing the life-time of WSNs and,as a result,allowing for faster data *** cluster-ing algorithm’s goal is to select the best cluster head(ch).In the existing system,Hybrid grey wolf sunﬂower optimization algorithm(HGWSFO)and optimal clus-ter head selection method is *** does not provide better competence and out-put in the ***,the proposed Hybrid Grey Wolf Ant Colony Optimisation(HGWACO)algorithm is used for reducing the energy utilization and enhances the lifespan of the *** hole method is used for selecting the cluster heads(chs).The ant colony optimization(ACO)technique is used toﬁnd the route among origin ch and *** open cache of nodes,trans-mission power,and proximity are used to improve the ch *** grey wolf optimisation(GWO)technique is the most recent and well-known optimiser module which deals with grey wolves’hunting activity(GWs).These GWs have the ability to track down and encircle *** GWO method was inspired by this hunting *** proposed HGWACO improves the duration of the net-work,minimizes the power consumption,also it works with the large-scale *** HGWACO method achieves 25.64%of residual energy,25.64%of alive nodes,40.65%of dead nodes also it enhances the lifetime of the network.

关键词： Energy efﬁciency power consumption lifespan of the network black hole method ant colony optimisation routing and cluster heads(chs)

Relay-assisted wireless energy harvesting for multihop clustered IoT network

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Intelligent and Converged Networks 2023年第3期4卷 206-224页

作者： B.Pavani K.Venkata Subbareddy L.Nirmala devi the Department of Electronics and Communication Engineering University College of EngineeringOsmania UniversityHyderabad 500007India

In large-scale networks such as the Internet of Things(IoT),devices seek multihop communication for longdistance communications,which considerably impacts their power ***,this study proposes an energy harvesting-enabled,relay-based communication in multihop clustered IoT networks in a bid to conserve the battery power in multihop IoT ***,this study proposes an efficient,hierarchical clustering mechanism in which entire IoT devices are clustered into two types:the closest cluster(CC)and remote clusters(RCs).Additionally,Euclidean distance is employed for the CC and fuzzy c-means for the ***,for cluster head(ch)selection,this study models a fitness function based on two metrics,namely residual energy and distance(device-to-device distance and device-to-sink distance).After ch selection,the entire clustered network is partitioned into several layers,after which a relay selection mechanism is *** every ch of the upper layer,we assign a few lower-layer chs to function as *** relay selection mechanism is applied only for the devices in the RCs,while for devices in the CC,the ch functions as a ***,several simulation experiments are conducted to validate the proposed method’s *** results show the method’s superiority in terms of energy efficiency and optimal number of relays in comparison with the state-of-the-art methods.

关键词： Internet of Things(IoT) energy management clustering cluster head selection relay selection

Synthesis, characterization and Biological Activity Studies on Novel 4-chloro-2- [(1-Phenyl-1H-Tetrazol-5-Ylimino)-Methyl] Phenol and Its Metal Complexes

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Journal of Materials Science and chemical Engineering 2015年第10期3卷 45-59页

作者： Ranjithreddy Palreddy Jaheer Mohmed Nagula Narsimha Boinala Aparna Mariyam ch. Sarala devi Department of chemistry University College of Science Osmania University Hyderabad India

Novel 4-chloro-2-[(1-phenyl-1H-tetrazol-5-ylimino)-methyl] phenol (Cl-PTMP) and its transition metal complexes were synthesized and characterized by FT-IR, 1H-NMR, UV-Vis spectroscopy, Mass spectrometry, TGA and SEM. The pH-metric technique was applied to get an insight of the number of dissociable protons and protonation sites in candidate compound. The pH-Metric studies were also carried out in presence of metal ions to establish the formation of corresponding metal complexes in solution. Further, the metal ligand compositions of Cu (II) and Co (II) complexes were determined spectrophotometrically by employing Job’s continuous variation method. To know the molecular properties in title imine compound suitable for metal ion coordination, the computational studies were carried out by employing Hyperchem 7.5 tools. The energies of HOMO and LUMO frontier orbitals and their electron density contour maps were generated with geometry optimized molecule. Biological activity of Cl-PTMP and its metal complexes was investigated by disc diffusion method.

关键词： Synthesis Cu (II) and Co (II) Complexes pH-Metry Spectro-Analytical and Biological Studies

Thyroid dysfunction and developmental anomalies in first degree relatives of children with thyroid dysgenesis

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World Journal of Pediatrics 2016年第2期12卷 215-218页

作者： Lakshminarasimhan Sindhuja devi Dayal Kushaljit Singh Sodhi Naresh Sachdeva Anish Bhattacharya Pediatric Endocrinology Unit Department of PediatricsPostgraduate Institute of Medical Education and ResearchChandigarh Department of Radiodiagnosis Postgraduate Institute of Medical Education and ResearchChandigarh Department of Endocrinology Postgraduate Institute of Medical Education and ResearchChandigarh Department of Nuclear Medicine Postgraduate Institute of Medical Education and ResearchChandigarh

Background: Familial clustering in patients withpermanent congenital hypothyroidism (ch) caused bythyroid dysgenesis (TD) has been reported in developedcountries. There is no information on familial TD fromdeveloping ***: A total of 312 first degree relativesbelonging to 80 families of children with TD (group 1)and 40 families of age-matched normal children (group2) were screened by thyroid ultrasonography, serum totalthyroxine (T4) and thyroid stimulating hormone (TSH).Results: Thyroid scintigraphy revealed agenesis in78.7% of the patients, ectopic gland in 15%, and hypoplasiain 6.2%. The mean thyroid volumes were similar in parentsand siblings of both groups. Eight (10.6%) mothers in group1 were identified to have thyroid hypoplasia as comparedwith none in group 2 (P=0.03). Serum TSH was signifi cantlyhigher in group 1 than in group 2 (P=0.004). Sixteen (7.8%)subjects (6 mothers, 5 fathers, and 5 siblings) in group 1were found to have subclinical hypothyroidism as comparedto none in group 2 (Pchildren with TD as compared with acontrol population. These findings suggest that possiblythere is a genetic component of TD in Indian patients.

关键词： congenital hypothyroidism familial occurrence first degree relatives thyroid developmental anomalies thyroid dysgenesis

Climate change evidence in tree growth and stand productivity at the upper treeline ecotone in the Polar Ural Mountains

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Forest Ecosystems 2020年第1期7卷 76-91页

作者： Nadezhda M.devi Vladimir V.Kukarskih Аrina A.Galimova Valeriy S.Mazepa Andrey A.Grigoriev Institute of Plant and Animal Ecology Ural BranchRussian Academy of Sciences8 Marta202/3Ekaterinburg 620144Russia

Background:Recent warming is affecting species composition and species areal distribution of many ***,although most treeline studies have estimated the rates of forest expansion into tundra,still little is known about the long-term dynamic of stand productivity at the forest-tundra ***,we make use of tree-ring data from 350 larch(Larix sibirica Ledeb.)and spruce(Picea obovata Ledeb.)sampled along the singular altitudinal treeline ecotone at the Polar Urals to assess the dynamic of stand establishment and productivity,and link the results with meteorological observations to identify the main environmental ***:The analysis of stand instalment indicated that more than 90%of the living trees appeared after *** this period,the stand became denser and moved 50m upward,while in recent decades the trees of both species grew *** maximum afforestation occurred in the last decades of the twentieth century,and the large number of encountered saplings indicates that the forest is still *** upward shift coincided with a slight increase of May-August and nearly doubling of September-April precipitation while the increase in growth matched with an early growth season warming(June+0.27°C per decade since 1901).This increase in radial growth combined with the stand densification led to a 6-90 times increase of biomass since ***:Tree-ring based twentieth century reconstruction at the treeline ecotone shows an ongoing forest densification and expansion accompanied by an increased *** changes are driven by climate change mechanism,whereby the leading factors are the significant increase in May-June temperatures and precipitation during the dormant *** of phytomass accumulation mechanisms within treeline ecotone is valuable for improving our understanding of carbon dynamics and the overall climate balance in current treeline ecosystems and for predicting how these will be altered by global ch

关键词： Polar Urals Treeline Productivity Climate change Radial growth Recruitment Larch Spruce

Enabling Reaction Selectivity of Platinum Catalysts by Photoinduced Electronic Effects

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Precision chemistry 2023年第4期1卷 248-255页

作者： Kowsalya devi Rasamani Xinyan Dai Matthew Messner Cunming Liu Xiaoyi Zhang Yugang Sun Department of chemistry Temple UniversityPhiladelphiaPennsylvania 19122USA

Reaction selectivity is crucial to producing target molecules of importance with minimum *** work reports an efficient and green strategy to improve reaction selectivity in visible-light-mediated chemical transformations by employing Pt/SiOx photocatalysts,which is ascribed to light-induced surface electronic modification in the small Pt *** strategy has been successfully applied to synthesize commercially valuable but thermodynamically unfavorable arylhydroxylamines with high selectivity via partial hydrogenation of the respective *** modification of the small Pt nanocrystals with triethanolamine(TEA)molecules further optimizes the Pt electronic structure to favor the reaction *** light-induced surface electronic structure alterations and the TEA chemical modification act synergistically to prevent the readsorption of desorbed electron-rich *** prevents the complete hydrogenation of arylhydroxylamines to respective anilines,leading to high arylhydroxylamine selectivity of 81−91%.In addition,photoillumination of Pt nanocrystals always accelerates the reaction kinetics significantly regardless of their surface modification.

关键词： selective photocatalysis enhanced plasmonic absorption hot-electron-driven chemistry photoinduced adsorption/desorption dielectric scattering resonance selective hydrogenation