867 research outputs found

    A new coupling solution for G3-PLC employment in MV smart grids

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    This paper proposes a new coupling solution for transmitting narrowband multicarrier power line communication (PLC) signals over medium voltage (MV) power lines. The proposed system is based on an innovative PLC coupling principle, patented by the authors, which exploits the capacitive divider embedded in voltage detecting systems (VDS) already installed inside the MV switchboard. Thus, no dedicated couplers have to be installed and no switchboard modifications or energy interruptions are needed. This allows a significant cost reduction of MV PLC implementation. A first prototype of the proposed coupling system was presented in previous papers: it had a 15 kHz bandwidth useful to couple single carrier PSK modulated PLC signals with a center frequency from 50–200 kHz. In this paper, a new prototype is developed with a larger bandwidth, up to 164 kHz, thus allowing to couple multicarrier G3-PLC signals using orthogonal frequency division multiplexing (OFDM) digital modulation. This modulation ensures a more robust communication even in harsh power line channels. In the paper, the new coupling system design is described in detail. A new procedure is presented for tuning the coupling system parameters at first installation in a generic MV switchboard. Finally, laboratory and in-field experimental test results are reported and discussed. The coupling performances are evaluated measuring the throughput and success rate in the case of both 18 and 36 subcarriers, in one of the different tone masks standardized for the FCC-above CENELEC band (that is, from 154.6875–487.5 kHz). The experimental results show an efficient behavior of the proposed coupler allowing a two-way communication of G3-PLC OFDM signals on MV networks

    ANAEROBIC DIGESTION AS CENTRE OF DAIRY LIVESTOCK AND AGRICULTURE INTEGRATION: BASIS FOR MEDIUM-SCALE CDM PROJECTS DEVELOPMENT

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    Dairy producers should improve their activity with modern production techniques/technologies to meet the requirements of a stricter consumer market. In this sense, crop and livestock systems integration represents an interesting alternative for using the dairy farm available resources. This paper analyses the use of anaerobic digestion as basis for supplying energy, fertilizers and feed needs of a farming unit, by means of digestion products usage: biogas, which can be used in energy conversion systems to provide the required energy for processing/conservation equipment for milk and other farming products; and effluent, that can be used as a replacement for chemical fertilizers and for aquatic plants/fish feeding. Fossil fuels replacement by biogas can be classified as a Clean Development Mechanism (CDM) project, and economic resources obtained by carbon credits commercialisation may support the required production modernisation. The paper analyses the anaerobic digestion process, evaluating biogas in medium-scale dairy farms, as well as the quantification of carbon credits generated by introducing proper manure and culture remains management

    Iron and liver diseases.

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    A mild to moderate iron excess is found in patients with liver diseases apparently unrelated to genetic hemochromatosis. Iron appears to affect the natural history of hepatitis C virus-related chronic liver diseases, alcoholic liver disease and nonalcoholic steatohepatitis by leading to a more severe fibrosis and thus aiding the evolution to cirrhosis.Ahigher frequency of mutations of the HFE gene, the gene responsible for hereditary hemochromatosis, is found in patients with liver diseases and increased liver iron than in normal patients. Patients with excess iron are potentially at a higher risk of developing hepatocellular carcinoma. Iron depletion therapy could interfere with fibrosis development and possibly reduce the risk of liver cancer occurrence

    Cervical spondylotic myelopathy: what the neurologist should know

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    Cervical spondylotic myelopathy is a wellknown cause of disability among older people. A significant amount of these patients is asymptomatic. Once the symptoms start the worsening may follow a progressive manner. We should suspect of spondylotic myelopathy in any individual over 55 years presenting progressive changes in gait or losing fine motor control of the upper limbs. Despite its frequent prevalence, this condition is still neglected and many times confused with other supratentorial lesions regarding diagnostic. Here we address some of most important aspects of this disease, calling attention to pathophysiology, the natural history. presentation, differential diagnosis, clinical assessment and treatment.Natl Inst Traumatol & Orthoped, Rio de Janeiro, BrazilUniv Severino Sombra, Div Neurol, Grad Program Neurol Neurosci, Tavares Macedo St 95-902, BR-24220215 Vassouras, RJ, BrazilUniv Severino Sombra, Masters Program Urgencia & Emergencia Med, Vassouras, RJ, BrazilUniv Fed Estado Rio de Janeiro, Sch Med, Rio de Janeiro, RJ, BrazilNeurology Division, Universidade Federal de São Paulo - UNIFESP , São Paulo, SP. BrazilUniv Fed Fluminense, Div Neurosurg, Niteroi, RJ, BrazilNeurology Division, Universidade Federal de São Paulo - UNIFESP , São Paulo, SP. BrazilWeb of Scienc

    Resting state functional thalamic connectivity abnormalities in patients with post-stroke sleep apnoea: a pilot case-control study

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    OBJECTIVE: Sleep apnoea is common after stroke, and has adverse effects on the clinical outcome of affected cases. Its pathophysiological mechanisms are only partially known. Increases in brain connectivity after stroke might influence networks involved in arousal modulation and breathing control. The aim of this study was to investigate the resting state functional MRI thalamic hyper connectivity of stroke patients affected by sleep apnoea (SA) with respect to cases not affected, and to healthy controls (HC). PATIENTS AND METHODS: A series of stabilized strokes were submitted to 3T resting state functional MRI imaging and full polysomnography. The ventral-posterior-lateral thalamic nucleus was used as seed. RESULTS: At the between groups comparison analysis, in SA cases versus HC, the regions significantly hyper-connected with the seed were those encoding noxious threats (frontal eye field, somatosensory association, secondary visual cortices). Comparisons between SA cases versus those without SA, revealed in the former group significantly increased connectivity with regions modulating the response to stimuli independently to their potentiality of threat (prefrontal, primary and somatosensory association, superolateral and medial-inferior temporal, associative and secondary occipital ones). Further significantly functionally hyper connections were documented with regions involved also in the modulation of breathing during sleep (pons, midbrain, cerebellum, posterior cingulate cortices), and in the modulation of breathing response to chemical variations (anterior, posterior and para-hippocampal cingulate cortices). CONCLUSIONS: Our preliminary data support the presence of functional hyper connectivity in thalamic circuits modulating sensorial stimuli, in patients with post-stroke sleep apnoea, possibly influencing both their arousal ability and breathing modulation during sleep

    Improving the accuracy of RF alternate test using multi-VDD conditions: application to envelope-based test of LNAs

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    Trabajo presentado al "20 Asina Test Symposium" celebrado en Nueva Delhi (India) del 20 al 23 de Noviembre del 2011.-- Reprinted from (relevant publication info). This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of the products or services of CSIC Spanish National Research Council, Digital.CSIC. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.This work demonstrates that multi-VDD conditions may be used to improve the accuracy of machine learning mod- els, significantly decreasing the prediction error. The proposed technique has been successfully applied to a previous alternate test strategy for LNAs based on response envelope detection. A prototype has been developed to show its feasibility. The prototype consists of a low-power 2.4GHz LNA and a simple envelope detector, integrated in a 90nm CMOS technology. Post- layout simulation results are provided to verify the functionality of the approach. Copyright © 2011 IEEE.This work has been partially funded by a CSIC JAE-Doc contract (cofinanced by FSE), a Spanish MAE-AECID grant and projects: SR2 - Short Range Radio (Catrene European project 2A105SR2 and Avanza I+D Spanish project TSI-020400-2010-55, cofinanced with FEDER program), Auto-calibración y auto-test en circuitos analógicos, mixtos y de radio frecuencia (Andalusian Government project P09-TIC-5386, cofinanced with FEDER program), and Catrene project TOETS (CT 302).Peer reviewe

    Diagnostic and prognostic role of liquid biopsy in non-small cell lung cancer: evaluation of circulating biomarkers

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    Lung cancer is still one of the main causes of cancer-related death, together with prostate and colorectal cancers in males and breast and colorectal cancers in females. The prognosis for non-small cell lung cancer (NSCLC) is strictly dependent on feasibility of a complete surgical resection of the tumor at diagnosis. Since surgery is indicated only in early stages tumors, it is necessary to anticipate the timing of diagnosis in clinical practice. In the diagnostic and therapeutic pathway for NSCLC, sampling of neoplastic tissue is usually obtained using invasive methods that are not free from disadvantages and complications. A valid alternative to the standard biopsy is the liquid biopsy (LB), that is, the analysis of samples from peripheral blood, urine, and other biological fluids, with a simple and non-invasive collection. In particular, it is possible to detect in the blood different tumor derivatives, such as cell-free DNA (cfDNA) with its subtype circulating tumor DNA (ctDNA), cell-free RNA (cfRNA), and circulating tumor cells (CTCs). Plasma-based testing seems to have several advantages over tumor tissue biopsy; firstly, it reduces medical costs, risk of complications related to invasive procedures, and turnaround times; moreover, the analysis of genes alteration, such as EGFR, ALK, ROS1, and BRAF is faster and safer with this method, compared to tissue biopsy. Despite all these advantages, the evidences in literatures indicate that assays performed on liquid biopsies have a low sensitivity, making them unsuitable for screening in lung cancer at the current state. This is caused by lack of standardization in sampling and preparation of specimen and by the low concentration of biomarkers in the bloodstream. Instead, routinely use of LB should be preferred in revaluation of patients with advanced NSCLC resistant to chemotherapy, due to onset of new mutations

    Exploring Pompeii: discovering hospitality through research synergy

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    Hospitality research continues to broaden through an ever-increasing dialogue and alignment with a greater number of academic disciplines. This paper demonstrates how an enhanced understanding of hospitality can be achieved through synergy between archaeology, the classics and sociology. It focuses on classical Roman life, in particular Pompeii, to illustrate the potential for research synergy and collaboration, to advance the debate on hospitality research and to encourage divergence in research approaches. It demonstrates evidence of commercial hospitality activities through the excavation hotels, bars and taverns, restaurants and fast food sites. The paper also provides an example of the benefits to be gained from multidisciplinary analysis of hospitality and tourism

    A Line Impedance Calculator Based on a G3 PLC Modem Platform

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    Power line communication (PLC) is one of the most today used technologies for both automatic meter reading and many other smart grid applications. In this framework, a characterization of the electrical network in the PLC frequency range is needed in terms of impedance measurement and received signal level. This can allow choosing the most suitable and less noisy frequency ranges for PLC transmission. Usually, these characterization measurements are performed with dedicated instrumentation and in the absence of mains voltage. This article wants to propose an alternative solution, which allows these kinds of measurements to be performed using electronic boards currently used as on-field applications, such as smart meters. To this aim, an innovative measurement tool is proposed, which does not need a specific characterization signal to be injected because it uses the preamble of a generic PLC transmission. Moreover, the impedance calculation is performed using an FFT analysis, which does not require high computational capabilities. These features allowed the proposed tool to be implemented using a G3-PLC transceiver, embedded in many commercial smart meters, and low-cost additional hardware. This article shows how the proposed system correctly measures the PLC impedance on CENELEC A, B, and FCC frequency ranges
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