84 research outputs found

    Effect of Graphene Interface on Potassiation in a Graphene- Selenium Heterostructure Cathode for Potassium-ion Batteries

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    Selenium (Se) cathodes are an exciting emerging high energy density storage system for Potassium ion batteries(KIB), where potassiation reactions are less understood. Here, we present an atomic-level investigation of KxSe cathode enclosed in hexagonal lattices of carbon(C) characteristic of multilayered graphene matrix and multiwalled carbon nanotubes (MW-CNTs). Microstructural changes directed by graphene substrate in KxSe cathode are contrasted with graphene-free cathode. Graphene's binding affinity for long-chain polyselenides (Se-Se-Se = -2.82 eV and Se-Se = -2.646 eV) and ability to induce reactivity between Se and K are investigated. Furthermore, intercalation voltage for graphene enclosed KxSe cathode reaction intermediates are calculated with K2Se as the final discharged product. Our results indicate a single-step reaction near a voltage of 1.55 V between K and Se cathode. Our findings suggest that operating at higher voltages (~2V) could result in the formation of reaction intermediates where intercalation/deintercalation of K could be a challenge, and therefore cause irreversible capacity losses in the battery. Primary issues are the high binding energy of long-chain polyselenides with graphene that discourage K storage and Se-Se bond dissociation at low K concentrations. A comparison with graphene-free cathode highlights the substantial changes a van der Waals (vdW) graphene interface can bring in atomic-structure and electrochemistry of the KxSe cathode.Comment: 7 Figures and 1 Tabl

    Variation in interface strength of Silicon with surface engineered Ti3C2 MXenes

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    Current advancements in battery technologies require electrodes to combine high-performance active material such as Silicon (Si) with two-dimensional materials such as transition metal carbides (MXenes) for prolonged cycle stability and enhanced electrochemical performance. More so, it is the interface between these materials, which is the nexus for their applicatory success. Herein, the interface strength variations between amorphous Si and Ti3C2Tx MXene are determined as the MXene surface functional groups (Tx) are changed using first-principle calculations. Si is interfaced with three Ti3C2 MXene substrates having surface -OH, -OH and -O mixed, and -F functional groups. Density functional theory (DFT) results reveal that completely hydroxylated Ti3C2 has the highest interface strength of 0.563 J/m2 with amorphous Si. This interface strength value drops as the proportion of surface -O and -F groups increases. Additional analysis of electron redistribution and charge separation across the interface is provided for a complete understanding of underlying physiochemical factors affecting the surface chemistry and resultant interface strength values. The presented comprehensive analysis of the interface aims to aid in developing sophisticated MXene based electrodes by their targeted surface engineering.Comment: 21 pages with 4 figures and. 3 tabl

    Prioritized Service Scheme with QoS Provisioning in a Cloud Computing System

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    A priority scheme is proposed in which the prioritized customers get guaranteed Quality of Service (QoS) by the cloud computing system in terms of lesser response time. The concept of selection probability is introduced according to which the cloud metascheduler chooses the next query for execution. The prioritized customers are categorized into different priority queues which are modeled as M/M/1/K/K queues and an analytical model is developed for the calculation of selection probabilities. Two algorithms are proposed for explaining the processing at the users’ end and at the cloud computing server’s end. The results obtained are validated using the numerical simulations

    Role of Analytics in Talent Management: A study in Pharmaceutical Sector

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    Effective people management is essential for ongoing success in thehighly competitive pharmaceutical industry. This research explores howanalytics shapes personnel management strategies and providesinformation on how workforce dynamics may be optimized through datadriven techniques. The study, which focuses on the pharmaceuticalsector, investigates how analytics may revolutionize important aspects ofpersonnel management such as hiring, training, and succession planning.Based on an extensive analysis of previous research, industry casestudies, and expert interviews, the paper presents a sophisticatedinterpretation of how analytics integration fits into people managementstrategies. The three main pillars of the research are the application ofanalytics in succession planning, performance analytics for ongoingdevelopment, and predictive analytics in talent acquisition. The researchdemonstrates the use of predictive analytics in talent acquisition,highlighting the ways in which pharmaceutical companies manipulatedata to locate and entice highly qualified applicants. The study looks athow analytics support succession planning, which is important in a fieldthat is advancing quickly. It clarifies how businesses use data to find,develop, and prepare future leaders. The findings deepen ourunderstanding of the useful implications of analytics in personnelmanagement and provide insightful advice for companies managing laborcomplexity. This research bridges theory and practice and empowersbusinesses to make educated decisions about using analytics forsuccessful people management in the dynamic pharmaceutical industr

    Infection status of Clinostomum complanatum (Rudolphi, 1819) metacercaria from Channa punctatus of Meerut District

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    Metacercaria Clinostomum complanatum is a digenetic trematode, which is mainly found in fresh water fishes. Present communication deals with the infection status of C. complanatum in C. punctatus of Meerut district, which is supported by the data spreading over one year. About 250 specimens of C. punctatus from different ponds of Meerut were studied through regular periodical collection in the year Jan 2010 to Dec 2010. Overall prevalence 35.6%, mean intensity 3.06 and abundance 1.09 were reported. The infection was maximum in winter and minimum in rainy season. Prevalence, intensity and abundance of the infestation were also found to be related to different length group and sex of the hosts, the medium sized fishes were more infected and the larger size fishes were less infected while the smaller size fishes showed moderate infection. Susceptibility of infection was not significantly different between male and female fish

    Adaptive batching scheme for multicast near video-on-demand (nvod) system

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    Video-on-Demand is becoming most sought after multimedia applications. It is difficult to attain a true video-on-demand (TVOD) system, so near video-on-demand (NVOD) is catching the attention of people. In NVOD, requests are multicast in different streams. Important issue in this system is the choice of batching time. Traditionally the batching time is fixed depending on the number of requests. In this paper we have suggested an adaptive batching scheme (ABS) where batching time is adjusted according to the current arrival rate, which follows the hyper-exponential distribution pattern. A comparison is made between the fixed and adaptive batching schemes. Numerical illustrations are provided to show that adaptive batching policy is better than fixed batching policy for optimizing bandwidth requirements

    Turbostratic Orientations, Water Confinement and Ductile-Brittle Fracture in Bi-layer Graphene

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    Bi-layer graphene (BLG) can be a cheaper and more stable alternative to graphene in several applications. With its mechanical strength being almost equivalent to graphene, BLG also brings advanced electronic and optical properties to the table. Furthermore, entrapment of water in graphene-based nano-channels and devices has been a recent point of interest for several applications ranging from energy to bio-physics. Therefore, it is crucial to study the over-all mechanical strength of such structures in order to prevent system failures in future applications. In the present work, Molecular Dynamics simulations have been used to study crack propagation in BLG with different orientations between the layers. There is a major thrust in analyzing how the angular orientation between the layers affect the horizontal and vertical crack propagation in individual layers of graphene. The study has been extended to BLG with confined water in interfaces. Over-all strength of graphene sheets when in contact with water content has been determined, and prominent regional conditions for crack initiation are pointed out. It was seen that in the presence of water content, graphene deviated from its characteristic brittle failure and exhibited the ductile fracture mechanism. Origin of cracks in graphenes was located at the region where the density of water dropped near the graphene surface, suggesting that the presence of hydroxyl groups decelerate the crack formation and propagation in straining graphenes.Comment: 24 pages, 10 Figure
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