3,397 research outputs found

    Same-Sign Dilepton Excesses and Vector-like Quarks

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    Multiple analyses from ATLAS and CMS collaborations, including searches for ttH production, supersymmetric particles and vector-like quarks, observed excesses in the same-sign dilepton channel containing b-jets and missing transverse energy in the LHC Run 1 data. In the context of little Higgs theories with T parity, we explain these excesses using vector-like T-odd quarks decaying into a top quark, a W boson and the lightest T-odd particle (LTP). For heavy vector-like quarks, decay topologies containing the LTP have not been searched for at the LHC. The bounds on the masses of the T-odd quarks can be estimated in a simplified model approach by adapting the search limits for top/bottom squarks in supersymmetry. Assuming a realistic decay branching fraction, a benchmark with a 750 GeV T-odd b-prime quark is proposed. We also comment on the possibility to fit excesses in different analyses in a common framework.Comment: 1+17 pages and 11 figure

    Solid-state NMR Study on Solid Amine Sorbents

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    Solid-state NMR spectroscopy is a useful structural tool, with a high sensitivity to the local atomic-scale environment providing a powerful probe of structure, disorder, and dynamics of solids. In this dissertation, solid-state NMR was used to characterize chemisorbed products of solid amine sorbents exposed to CO2. Solid amine sorbents are promising candidates to capture CO2 for the purposes of mitigation of this greenhouse gas in high-concentration sources, such as flue gases emitted from power plants or industrial sites. Understanding the adsorption process of these solid materials is critical to help design better materials to have a higher CO2 uptake. A series of solid-state NMR methods were employed to study these materials.15N CPMAS of primary amines (APS) before and after 13CO2 was employed, and the result is informative. With the time-evolution of signals before and after CO2 exposure, the decreased intensity of the reactant resonance and increased intensity of the products’ resonances, we were able to assign amine, ammonium, and carbamate in 15N spectra. Complementary 13C{15N} REDOR and 15N{13C} REDOR of a primary amine (APS) were used to obtain the 13C-15N dipolar interaction of the chemisorbed product species corresponding the distances of both directly-bonded C-N of carbamate and the distant interaction between of carbamate to its ammonium counter ion that is ion-paired to it. Under humid (or damp) conditions, hydrated bicarbonate was found in three types of amine: primary, secondary, and tertiary. NMR measurements show the hydrated bicarbonate undergoes dynamic motion at room temperature induced by surrounding water. Different water environments lead to chemically-inequivalent bicarbonates, which results in two 13C signals when bicarbonate is cooled down (100 K). Exposure to D2O, replacing water, allowed for interactions between the two bicarbonate species and the surrounding environments to be elucidated, via low-temperature 13C-1H HETCOR. Additionally, dynamic nuclear polarization (DNP) NMR was successfully performed on primary amines (APS). 2D DNP HETCOR was used to determine the interactions between carbamate pendant molecules and the surrounding environment. 13C-1H HETCOR, 15N-1H HETCOR, and 29Si-1H HETCOR (all using enhancements provided by DNP) were performed, and the results show coupling between carbamate and the hydroxyl groups on the SBA15 (silica) surface

    Enabling System-Level Modeling of Variation-Induced Faults in Networks-on-Chip

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    Process Variation (PV) is increasingly threatening the reliability of Networks-on-Chips. Thus, various resilient router designs have been recently proposed and evaluated. However, these evaluations assume random fault distributions, which result in 52%--81% inaccuracy. We propose an accurate circuit-level fault-modeling tool, which can be plugged into any system-level NoC simulator, quantify the system-level impact of PV-induced faults at runtime, pinpoint fault-prone router components that should be protected, and accurately evaluate alternative resilient multi-core designs.GigaScale Systems Research CenterFocus Center Research Program. Focus Center for Circuit & System Solutions. Semiconductor Research Corporation. Interconnect Focus Cente

    Rapid identification of Mycobacterium tuberculosis infection by a new array format-based surface plasmon resonance method

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    Tubercle bacillus [TB] is one of the most important chronic infectious diseases that cause millions of deaths annually. While conventional smear microscopy and culture methods are widely used for diagnosis of TB, the former is insensitive, and the latter takes up to 6 to 8 weeks to provide a result, limiting the value of these methods in aiding diagnosis and intermediate decisions on treatment. Therefore, a rapid detection method is essential for the diagnosis, prognosis assessment, and recurrence monitoring. A new surface plasmon resonance [SPR] biosensor based on an array format, which allowed immobilizing nine TB antigens onto the sensor chip, was constructed. Simultaneous determination of multiple TB antibodies in serum had been accomplished with this array-based SPR system. The results were compared with enzyme-linked immunosorbent assay, a conventional immunological method. Array-based SPR showed more advantages in providing label-free and real-time detection. Additionally, the high sensitivity and specificity for the detection of TB infection showed its potential for future development of biosensor arrays for TB diagnosis

    COMPARISON OF KINESIO TAPING AND SPORTS TAPING IN FUNCTIONAL ACTIVITIES FOR COLLEGIATE BASKETBALL PLAYERS: A PILOT STUDY

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    The purpose of this study was to identify the effects of kinesio taping and sports taping for collegiate basketball players in functional activities. Seventeen collegiate basketball players were recruited in particapitate this study and divided into three groups(Kinesio taping group, sports taping group and control group) in random. The ankle range of motion, plantarflexor muscle strength and endurance, vertical jump, and dynamic balance were measured before and after taping applied. The results was showed significantly increasing in ankle plantar-flexion range for Kinesio taping group(p=.03). There were no remarkable difference in the other measurements. In conclusion, the Kinesio Taping would not restriction the ankle plantar-flexion range. In future, we may recruited more subjects to identify the effect of Kinesio taping in functional activities for collegiate bsketball players

    Phase and Amplitude Responses of Narrow-Band Optical Filter Measured by Microwave Network Analyzer

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    The phase and amplitude responses of a narrow-band optical filter are measured simultaneously using a microwave network analyzer. The measurement is based on an interferometric arrangement to split light into two paths and then combine them. In one of the two paths, a Mach-Zehnder modulator generates two tones without carrier and the narrow-band optical filter just passes through one of the tones. The temperature and environmental variations are removed by separated phase and amplitude averaging. The amplitude and phase responses of the optical filter are measured to the resolution and accuracy of the network analyzer

    The Effects of Green Energy Production on Farmland: A Case Study in Yunlin County, Taiwan

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    Taiwan enacted the Act of Renewable Energy in the year 2009 which promotes energy safety, green economy, and a sustainable environment, and with that the government envisages a contribution of photovoltaic energy of up to 20% by the year 2025. In this study we look into the motivation and background of this energy policy, plans for implementation and associated challenges, and its actual consequences for farmland use and farmers. In addition, we take a look into the implementation of mixed-use farmland in which agricultural activity and photovoltaic installations are planned to coexist in order to increase land value and productivity. We furthermore report on some of our findings related to a field survey conducted in Taiwan’s corn chamber of Yunlin County which has been facing a number of socioeconomic challenges

    Assessing the Effects of Acupuncture by Comparing Needling the Hegu Acupoint and Needling Nearby Nonacupoints by Spectral Analysis of Microcirculatory Laser Doppler Signals

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    We aimed to assess the effects of acupuncture by analyzing the frequency content of skin blood-flow signals simultaneously recorded at the Hegu acupoint and two nearby nonacupoints following acupuncture stimulation (AS). Laser Doppler flowmetry (LDF) signals were measured in male healthy volunteers in two groups of experiments: needling the Hegu acupoint (n = 13) and needling a nearby nonacupoint (control experiment; n = 10). Each experiment involved recording a 20 min baseline-data sequence and two sets of effects data recorded 0–20 and 50–70 min after stopping AS. Wavelet transform with Morlet mother wavelet was applied to the measured LDF signals. Needling the Hegu acupoint significantly increased the blood flow, significantly decreased the relative energy contribution at 0.02–0.06 Hz and significantly increased the relative energy contribution at 0.4–1.6 Hz at Hegu, but induced no significant changes at the nonacupoints. Also, needling a nearby nonacupoint had no effect in any band at any site. This is the first time that spectral analysis has been used to investigate the microcirculatory blood-flow responses induced by AS, and has revealed possible differences in sympathetic nerve activities between needling the Hegu acupoint and its nearby nonacupoint. One possible weakness of the present design is that different De-Qi feelings following AS could lead to nonblind experimental setup, which may bias the comparison between needling Hegu and its nearby nonacupoint. Our results suggest that the described noninvasive method can be used to evaluate sympathetic control of peripheral vascular activity, which might be useful for studying the therapeutic effects of AS

    Transformer-based Image Compression with Variable Image Quality Objectives

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    This paper presents a Transformer-based image compression system that allows for a variable image quality objective according to the user's preference. Optimizing a learned codec for different quality objectives leads to reconstructed images with varying visual characteristics. Our method provides the user with the flexibility to choose a trade-off between two image quality objectives using a single, shared model. Motivated by the success of prompt-tuning techniques, we introduce prompt tokens to condition our Transformer-based autoencoder. These prompt tokens are generated adaptively based on the user's preference and input image through learning a prompt generation network. Extensive experiments on commonly used quality metrics demonstrate the effectiveness of our method in adapting the encoding and/or decoding processes to a variable quality objective. While offering the additional flexibility, our proposed method performs comparably to the single-objective methods in terms of rate-distortion performance
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