2,581 research outputs found

    The Hopf algebra structure of the Z3_3-graded quantum supergroup GLq,j(1∣1)_{q,j}(1|1)

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    In this work, we give some features of the Z3_3-graded quantum supergroup

    Infrared luminescence of annealed germanosilicate layers

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    Cataloged from PDF version of article.In the light of growing importance of semiconductor nanocrystals for photonics, we report on the growth and characterization of annealed germanosilicate layers used for Ge nanocrystal formation. The films are grown using plasma enhanced chemical vapor deposition (PECVD) and post-annealed in nitrogen at temperatures between 600 and 1200 degrees C for as long as 2 h. Transmission electron microscopy (TEM), Raman scattering and photoluminescence spectroscopy (PL) has been used to characterize the samples both structurally and optically. Formation of Ge precipitates in the germanosilicate layers have been observed using Raman spectroscopy for a variety of PECVD growth parameters, annealing temperatures and times. Ge-Ge mode at similar to 300 cm(-1) is clearly observed at temperatures as low as 700 degrees C for annealing durations for 45 min. Raman results indicate that upon annealing for extended periods of time at temperatures above 900 degrees C; nanocrystals of few tens of nanometers in diameter inside the oxide matrix and precipitation and interdiffusion of Ge, forming SiGe alloy at the silicon and oxide interface take place. Low temperature PL spectroscopy has been used to observe luminescence from these samples in the vicinity of 1550 nm, an important wavelength for telecommunications. Observed luminescence quenches at 140 K. The photoluminescence data displays three peaks closely interrelated at approximately 1490,, 1530 and 1610 nm. PL spectra persist even after removing the oxide layer indicating that the origin of the infrared luminescent centers are not related to the Ge nanocrystals in the oxide layer. (C) 2013 Elsevier B.V. All rights reserved

    Characterization of an embedded RF-MEMS switch

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    An RF-MEMS capacitive switch for mm-wave integrated circuits, embedded in the BEOL of 0.25ÎŒm BiCMOS process, has been characterized. First, a mechanical model based on Finite-Element-Method (FEM) was developed by taking the residual stress of the thin film membrane into account. The pull-in voltage and the capacitance values obtained with the mechanical model agree very well with the measured values. Moreover, S-parameters were extracted using Electromagnetic (EM) solver. The data observed in this way also agree well with the experimental ones measured up to 110GHz. The developed RF model was applied to a transmit/receive (T/R) antenna switch design. The results proved the feasibility of using the FEM model in circuit simulations for the development of RF-MEMS switch embedded, single-chip multi-band RF ICs

    Valproic Acid-Induced Hyperammonemia with Encephalopathy (VIHE): A Case Report

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    Valproic acid (VPA) is a wide spectrum antiepileptic medication indicated for seizure prophylaxis across the spectrum of epilepsy. Since coming into clinical use, VPA has also been recommended for the management of a variety of other pathologies, including, most notably, mood stabilization in the manic patient. VPA’s common adverse effects include gastrointestinal, influenza-like symptoms, headache, and difficulties with sleep; nonetheless, in rare instances, VPA has been noted to cause the severe and potentially lethal condition of hyperammonemia with encephalopathy (VIHE). VIHE is the result of a dose-independent increase in ammonia levels. Often the patient is asymptomatic; if symptoms reach clinical threshold, lethargy is most common, though seizures, focal neurologic deficits and even coma are possible. VIHE can occur in patients despite normal hepatic function, normal loading doses, chronic stable doses and normal free serum drug levels. Once the diagnosis is confirmed, the first approach for symptomatic patients is to discontinue VPA, start alternative mood stabilizer as indicated, and supplement hyperammonemia treatment with lactulose, carnitine or carglumic acid. Below is a case report of VIHE that developed in an adolescent girl with a history of Bipolar I Disorder who was hospitalized in our facility for stabilization of mania.  As demonstrated below, early diagnosis of VIHE is pivotal in reducing morbidity and ultimately can be life-saving

    The Future of Government: Lessons Learned from around the World

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    The report provides a summary of the discussions that have taken place within the framework of Forum activities on how the strategies, structures and practices of governments must change in the coming years, and how new networks and technologies can be leveraged to transform government capacity. It includes a series of policy briefs, which distils some of the most current and vital information for government modernization available, and concludes with case studies from around the world

    Lab and Field Evaluation of Fault Detection and Diagnostics for Advanced Roof Top Unit

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    In this paper, the results of lab and field evaluation of several RTU FDD technologies will be presented and discussed. The focus the study was on RTUs that provide cooling of small and medium commercial buildings. This work was conducted by UTRC in close collaboration Purdue University within Consortium for Building Energy Innovation (CBEI). The goal of the lab activity was to engineer and assess low-cost, embeddable fault detection and diagnostics (FDD) for a new RTU product that exceeds DOE\u27s High Performance RTU performance specification. Primary focus of evaluation was on overall unit performance degradation (COP and capacity) resulted from single and multiple operational faults. High confidence and low false alarm rate of COP degradation were demonstrated. The cost effectiveness of FDD will be discussed. Due to high interest and close engagement of Original Equipment Manufacturer (OEM) and National Account Customer field evaluation of FDD became possible. Several commercial sited with state-of-the-art RTUs were instrumented for continues monitoring of RTU performance and assessment of frequency of typical operational faults. Also some operational faults are intentionally injected in order evaluate FDD effectiveness. Several levels of FDD applicable in the field will be discussed

    Automated Nanofiber Diameter Measurement in SEM Images Using a Robust Image Analysis Method

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    Due to the high surface area, porosity, and rigidity, applications of nanofibers and nanosurfaces have developed in recent years. Nanofibers and nanosurfaces are typically produced by electrospinning method. In the production process, determination of average fiber diameter is crucial for quality assessment. Average fiber diameter is determined by manually measuring the diameters of randomly selected fibers on scanning electron microscopy (SEM) images. However, as the number of the images increases, manual fiber diameter determination becomes a tedious and time consuming task as well as being sensitive to human errors. Therefore, an automated fiber diameter measurement system is desired. In the literature, this task is achieved by using image analysis algorithms. Typically, these methods first isolate each fiber in the image and measure the diameter of each isolated fiber. Fiber isolation is an error-prone process. In this study, automated calculation of nanofiber diameter is achieved without fiber isolation using image processing and analysis algorithms. Performance of the proposed method was tested on real data. The effectiveness of the proposed method is shown by comparing automatically and manually measured nanofiber diameter values

    Human MST But Not MT Responds to Tactile Stimulation

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    Previous reports of tactile responses in human visual area MT/V5 have used complex stimuli, such as a brush stroking the arm. These complex moving stimuli are likely to induce imagery of visual motion, which is known to be a powerful activator of MT. The area described as “MT” in previous reports consists of at least two distinct cortical areas, MT and MST. Using functional magnetic resonance imaging, we separately localized human MT and MST and measured their response to vibrotactile stimuli unlikely to induce imagery of visual motion. Strong vibrotactile responses were observed in MST but not in MT. Vibrotactile responses in MST were approximately one-half as large as the response to visual motion and were distinct from those in another visual area previously reported to respond to tactile stimulation, the lateral occipital complex. To examine somatotopic organization, we separately stimulated the left and right hand and foot. No spatial segregation between hand and foot responses was observed in MST. The average response profile of MST was similar to that of somatosensory cortex, with a strong preference for the contralateral hand. These results offer evidence for the existence of somatosensory responses in MST, but not MT, independent of imagery of visual motion

    Reinforcing and neurochemical effects of cannabinoid CB1 receptor agonists, but not cocaine, are altered by an adenosine A2A receptor antagonist

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    Several recent studies suggest functional and molecular interactions between striatal adenosine A2A and cannabinoid CB1 receptors. Here, we demonstrate that A2A receptors selectively modulate reinforcing effects of cannabinoids. We studied effects of A2A receptor blockade on the reinforcing effects of delta‐9‐tetrahydrocannabinol (THC) and the endogenous CB1 receptor ligand anandamide under a fixed‐ratio schedule of intravenous drug injection in squirrel monkeys. A low dose of the selective adenosine A2A receptor antagonist MSX‐3 (1 mg/kg) caused downward shifts of THC and anandamide dose‐response curves. In contrast, a higher dose of MSX‐3 (3 mg/kg) shifted THC and anandamide dose‐response curves to the left. MSX‐3 did not modify cocaine or food pellet self‐administration. Also, MSX‐3 neither promoted reinstatement of extinguished drug‐seeking behavior nor altered reinstatement of drug‐seeking behavior by non‐contingent priming injections of THC. Finally, using in vivo microdialysis in freely‐moving rats, a behaviorally active dose of MSX‐3 significantly counteracted THC‐induced, but not cocaine‐induced, increases in extracellular dopamine levels in the nucleus accumbens shell. The significant and selective results obtained with the lower dose of MSX‐3 suggest that adenosine A2A antagonists acting preferentially at presynaptic A2A receptors might selectively reduce reinforcing effects of cannabinoids that lead to their abuse. However, the appearance of potentiating rather than suppressing effects on cannabinoid reinforcement at the higher dose of MSX‐3 would likely preclude the use of such a compound as a medication for cannabis abuse. Adenosine A2A antagonists with more selectivity for presynaptic versus postsynaptic receptors could be potential medications for treatment of cannabis abuse
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