2,088 research outputs found

    Preparation of Amidoxime Polyacrylonitrile Chelating Nanofibers and Their Application for Adsorption of Metal Ions.

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    Polyacrylonitrile (PAN) nanofibers were prepared by electrospinning and they were modified with hydroxylamine to synthesize amidoxime polyacrylonitrile (AOPAN) chelating nanofibers, which were applied to adsorb copper and iron ions. The conversion of the nitrile group in PAN was calculated by the gravimetric method. The structure and surface morphology of the AOPAN nanofiber were characterized by a Fourier transform infrared spectrometer (FT-IR) and a scanning electron microscope (SEM), respectively. The adsorption abilities of Cu2+ and Fe3+ ions onto the AOPAN nanofiber mats were evaluated. FT-IR spectra showed nitrile groups in the PAN were partly converted into amidoxime groups. SEM examination demonstrated that there were no serious cracks or sign of degradation on the surface of the PAN nanofibers after chemical modification. The adsorption capacities of both copper and iron ions onto the AOPAN nanofiber mats were higher than those into the raw PAN nanofiber mats. The adsorption data of Cu2+ and Fe3+ ions fitted particularly well with the Langmuir isotherm. The maximal adsorption capacities of Cu2+ and Fe3+ ions were 215.18 and 221.37 mg/g, respectively

    Quantum Impurity in Luttinger Liquid: Universal Conductance with Entanglement Renormalization

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    We study numerically the universal conductance of Luttinger liquids wire with a single impurity via the Muti-scale Entanglement Renormalization Ansatz (MERA). The scale invariant MERA provides an efficient way to extract scaling operators and scaling dimensions for both the bulk and the boundary conformal field theories. By utilizing the key relationship between the conductance tensor and ground-state correlation function, the universal conductance can be evaluated within the framework of the boundary MERA. We construct the boundary MERA to compute the correlation functions and scaling dimensions for the Kane-Fisher fixed points by modeling the single impurity as a junction (weak link) of two interacting wires. We show that the universal behavior of the junction can be easily identified within the MERA and argue that the boundary MERA framework has tremendous potential to classify the fixed points in general multi-wire junctions.Comment: 14 pages, 18 figure

    The Implementation of an Intelligent Logistics Tracking System Utilizing RFID

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    Due to globalization and the advancement of technology, the differences are lessened among businesses in terms of IT capabilities and product quality. Operation cost has become a critical key factor of success that determines company’s profit level, as well as its competence in the market. Under the environment of electronic-commerce, logistics in the supply chain ensures a stable supply of stocks to satisfy customer’s demands. An efficient supply chain requires a sound inventory system and operates in coordination with well designed shipping processes. Present shipping process uses barcode in tracking the flow of materials; however, scanning barcode one at a time is tedious and inefficient. Recently, RFID has been regarded as an important technology that influences the growth of global industries in the near future. RFID is able to effectively reduce the overall cost of logistics. However, application of RFID on supply chain management is still at its infant stage. Therefore, this research attempts to develop a prototype of a Smart Logistics Tracking System (SLTS) utilizing RFID. The proposed system aims to replace barcode with RFID, eradicate the time-consuming scanning procedure and ensures an efficient flow of materials. SLTS provides a cargo tracking platform that reports real-time location of the cargo and its flow

    DIFFERENCES IN SEGMENTAL MOMENTUM TRANSFERS BETWEEN TWO STROKE POSTURES FOR TENNIS TWO-HANDED BACKHAND STROKE

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    Tennis stroke force depends on momentum transfer from racket to ball during ball-racket impact. Previous researchers study backhand stroke mechanics, focusing on comparison of one-handed and two-handed backhand stroke biomechanics (Reid & Elliott, 2002). This study investigated linear (LM) and angular momentum (AM) transfer from the trunk and upper extremities to the racket in open (OS) and square stances (SS) for different skill levels of players in the two-handed backhand stroke

    The Influence of Customer’s Sharing Behavior in Social Commerce

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    All transaction behaviors between enterprises and customers directly take place on social media. Using social media for people to interact with their friends and family become a routine in the daily life. This study aims to figure out the critical factors and relations of brand community and social commerce. Meanwhile, this study is to investigate the influence on consumers’ engagement by considering the building of a brand community for social commerce. This study reviews many key literatures of social commerce and brand community. This study employs a survey base strategy to figure out the proposed research questions

    Characterizing First Arrival Position Channels: Noise Distribution and Capacity Analysis

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    This paper addresses two fundamental problems in diffusive molecular communication: characterizing the first arrival position (FAP) density and bounding the information transmission capacity of FAP channels. Previous studies on FAP channel models, mostly captured by the density function of noise, have been limited to specific spatial dimensions, drift directions, and receiver geometries. In response, we propose a unified solution for identifying the FAP density in molecular communication systems with fully-absorbing receivers. Leveraging stochastic analysis tools, we derive a concise expression with universal applicability, covering any spatial dimension, drift direction, and receiver shape. We demonstrate that several existing FAP density formulas are special cases of this innovative expression. Concurrently, we establish explicit upper and lower bounds on the capacity of three-dimensional, vertically-drifted FAP channels, drawing inspiration from vector Gaussian interference channels. In the course of deriving these bounds, we unravel an explicit analytical expression for the characteristic function of vertically-drifted FAP noise distributions, providing a more compact characterization compared to the density function. Notably, this expression sheds light on a previously undiscovered weak stability property intrinsic to vertically-drifted FAP noise distributions.Comment: 30 pages; 3 figures, 1 table; this paper is submitted to IEEE Transactions on Communication

    KINETIC ANALYSIS OF THE UPPER EXTREMITY BETWEEN DIFFERENT STANCES IN TENNIS TWO-HANDED BACKHAND

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    INTRODUCTION: Now the tennis players could explore more racket capabilities through the change of racket materials and design. The open stance comes out in modern tennis relative to the traditional square stance. This study was conducted to analyze the upper extremity joint forces and moments between the different stances in advanced and intermediate athletes, who separated from ITN rating system, during two-handed stroke
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