580 research outputs found

    RFID Tags / Planar Inductors as Chemical Sensor Platforms in Liquid Sensing Applications

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    In this work, RFID tags are investigated as a liquid-phase chemical sensing platform. A dual-layer of selective coating film with polyaniline (PANi) on top of poly(epichlorohydrin) (PECH) is used for the detection of trace amounts of organic compounds (toluene and ethylbenzene) in aqueous solutions. Various experiments were performed to evaluate the coated RFID tag sensors. Shifts in the impedance and resonant frequency due to analyte sorption are measured. Details of the responses of the dual-layer film to different pH baseline solutions are shown. The results show that this dual-layer film can be used to detect toluene and ethylbenzene with high sensitivity. The conductive nature of PANi when protonated with an acidic solution allowed for increased sensitivity. To describe the observed changes that occur during detection, an equivalent circuit model of the RFID tag chemical sensor was developed. The derived equations could be used to describe the observed response due to chemical sorption. The addition of PANi provided added sensitivity as the traces of the planar inductor began to effectively short out with increasing conductivity of the polymer. This is due to the different level of protonation of PANi that occurs. Lower pH solutions result in an increase in the conductivity of PANi to a level that drastically changes the characteristics of the coil (number of turns and width of the traces), thus shifting the operating resonant frequency. The large shift in frequency is related to a decrease in both the inductance and the capacitance of the coil. However, this shift would cause the tag to no longer operate with the reader. The results with the aqueous baseline solution of pH = 1 provides the largest sensitivity; however, the results with the aqueous baseline solution of pH = 3.5 also provides highly sensitive responses. Partial selectivity of the coated sensor was also found to be a function of the solution pH, thus the protonation of the PANi. For the present study, a limit of detection with a baseline solution of pH = 3.5 was found to be 6.24 ppb and 8.3 ppb for toluene and ethylbenzene, respectively

    The Holevo-Schumacher-Westmoreland Channel Capacity for a Class of Qudit Unital Channels

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    The Holevo-Schumacher-Westmoreland (HSW) classical (entanglement-unassisted) channel capacity for a class of qudit unital channels is shown to be C = log2(d) - Smin, where d is the dimension of the qudit, and Smin is the minimum possible von Neumann entropy at the channel output. The HSW channel capacity for tensor products of this class of unital qudit channels is shown to obey the same formula.Comment: 21 Pages. No Figure

    Optimal dense coding with mixed state entanglement

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    I investigate dense coding with a general mixed state on the Hilbert space CdCdC^{d}\otimes C^{d} shared between a sender and receiver. The following result is proved. When the sender prepares the signal states by mutually orthogonal unitary transformations with equal {\it a priori} probabilities, the capacity of dense coding is maximized. It is also proved that the optimal capacity of dense coding χ\chi ^{*} satisfies ER(ρ)χER(ρ)+log2dE_{R}(\rho)\leq \chi ^{*}\leq E_{R}(\rho )+\log_{2}d, where ER(ρ)E_{R}(\rho) is the relative entropy of entanglement of the shared entangled state.Comment: Revised. To appear in J. Phys. A: Math. Gen. (Special Issue: Quantum Information and Computation). LaTeX2e (iopart.cls), 8 pages, no figure

    Operator monotones, the reduction criterion and the relative entropy

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    We introduce the theory of operator monotone functions and employ it to derive a new inequality relating the quantum relative entropy and the quantum conditional entropy. We present applications of this new inequality and in particular we prove a new lower bound on the relative entropy of entanglement and other properties of entanglement measures.Comment: Final version accepted for publication, added references in reference [1] and [13

    Strengthened Lindblad inequality: applications in non equilibrium thermodynamics and quantum information theory

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    A strengthened Lindblad inequality has been proved. We have applied this result for proving a generalized HH-theorem in non equilibrium thermodynamics. Information processing also can be considered as some thermodynamic process. From this point of view we have proved a strengthened data processing inequality in quantum information theory.Comment: 7 pages, revte

    Shape Analysis of Traffic Flow Curves using a Hybrid Computational Analysis

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    This paper highlights and validates the use of shape analysis using Mathematical Morphology tools as a means to develop meaningful clustering of historical data. Furthermore, through clustering more appropriate grouping can be accomplished that can result in the better parameterization or estimation of models. This results in more effective prediction model development. Hence, in an effort to highlight this within the research herein, a Back-Propagation Neural Network is used to validate the classification achieved through the employment of MM tools. Specifically, the Granulometric Size Distribution (GSD) is used to achieve clustering of daily traffic flow patterns based solely on their shape. To ascertain the significance of shape in traffic analysis, a comparative classification analysis of original data and GSD transformed data is carried out. The results demonstrate the significance of functional shape in traffic analysis. In addition, the results validate the need for clustering prior to prediction. It is determined that a span of two through four years of traffic data is found sufficient for training to produce satisfactory BPNN performance

    Predicting Transcription Factor Specificity with All-Atom Models

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    The binding of a transcription factor (TF) to a DNA operator site can initiate or repress the expression of a gene. Computational prediction of sites recognized by a TF has traditionally relied upon knowledge of several cognate sites, rather than an ab initio approach. Here, we examine the possibility of using structure-based energy calculations that require no knowledge of bound sites but rather start with the structure of a protein-DNA complex. We study the PurR E. coli TF, and explore to which extent atomistic models of protein-DNA complexes can be used to distinguish between cognate and non-cognate DNA sites. Particular emphasis is placed on systematic evaluation of this approach by comparing its performance with bioinformatic methods, by testing it against random decoys and sites of homologous TFs. We also examine a set of experimental mutations in both DNA and the protein. Using our explicit estimates of energy, we show that the specificity for PurR is dominated by direct protein-DNA interactions, and weakly influenced by bending of DNA.Comment: 26 pages, 3 figure

    A quantum measure of coherence and incompatibility

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    The well-known two-slit interference is understood as a special relation between observable (localization at the slits) and state (being on both slits). Relation between an observable and a quantum state is investigated in the general case. It is assumed that the amount of ceherence equals that of incompatibility between observable and state. On ground of this, an argument is peresented that leads to a natural quantum measure of coherence, called "coherence or incompatibility information". Its properties are studied in detail making use of 'the mixing property of relative entropy' derived in this article. A precise relation between the measure of coherence of an observable and that of its coarsening is obtained and discussed from the intutitive point of view. Convexity of the measure is proved, and thus the fact that it is an information entity is established. A few more detailed properties of coherence information are derived with a view to investigate final-state entanglement in general repeatable measurement, and, more importantly, general bipartite entanglement in follow ups of this study.Comment: 19 GS pages; supercedes quant-ph/030921

    Quantum dynamics as a physical resource

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    How useful is a quantum dynamical operation for quantum information processing? Motivated by this question we investigate several strength measures quantifying the resources intrinsic to a quantum operation. We develop a general theory of such strength measures, based on axiomatic considerations independent of state-based resources. The power of this theory is demonstrated with applications to quantum communication complexity, quantum computational complexity, and entanglement generation by unitary operations.Comment: 19 pages, shortened by 3 pages, mainly cosmetic change
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