373 research outputs found

    Wavelet Based Simulation and Analysis of Single and Multiple Power Quality Disturbances

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    Improving power quality disturbance (PQD) detection and automatic classification has been a major concern ever since the emergence of sensitive non-linear devices. The role of distributed generation in a power system is the main source of PQDs. Short-term and long-term duration single and multiple complex PQDs are difficult to monitor and need higher accuracy and time. This paper presents the analysis of different and distinctive combinations of PQDs. Variety of single and multiple PQD samples are generated using Matlab environment conferring to IEEE STD 1159-2009. Such disturbance samples are accurately detected and analyzed from waveform patterns using multi resolution analysis based discrete wavelet transform. The generation of samples and detection lies in fact that it can allow the feature extraction process for the training/testing sample features for machine learning based automatic recognition of disturbance types

    Suspended silicon mid-infrared waveguide devices with subwavelength grating metamaterial cladding

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    We present several fundamental photonic building blocks based on suspended silicon waveguides supported by a lateral cladding comprising subwavelength grating metamaterial. We discuss the design, fabrication, and characterization of waveguide bends, multimode interference devices and Mach-Zehnder interferometers for the 3715 - 3800 nm wavelength range, demonstrated for the first time in this platform. The waveguide propagation loss of 0.82 dB/cm is reported, some of the lowest loss yet achieved in silicon waveguides for this wavelength range. These results establish a direct path to ultimately extending the operational wavelength range of silicon wire waveguides to the entire transparency window of silicon

    Mid-infrared Suspended Waveguide Platform and Building Blocks

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    In this work we present our recent progress in the development of a platform for the mid-infrared wavelength range, based on suspended silicon waveguide with subwavelength metamaterial cladding. The platform has some intrinsic advantages, which make it a very promising candidate for sensing applications in the fingerprint region. Specifically, it can cover the full transparency window of silicon (up to a wavelength of 8 μm), only requires one lithographic etch-step and can be designed for strong light-matter interaction. Design rules, practical aspects of the fabrication process and experimental results of a complete set of elemental building blocks operating at two very different wavelengths, 3.8 μm and 7.67 μm, will be discussed. Propagation losses as low as 0.82 dB/cm at λo=3.8 μm and 3.1 dB/cm at λo=7.67 μm are attained, for the interconnecting waveguides.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Low-loss slot waveguides with silicon (111) surfaces realized using anisotropic wet etching

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    We demonstrate low-loss slot waveguides on silicon-on-insulator (SOI) platform. Waveguides oriented along the (11-2) direction on the Si (110) plane were first fabricated by a standard e-beam lithography and dry etching process. A TMAH based anisotropic wet etching technique was then used to remove any residual side wall roughness. Using this fabrication technique propagation loss as low as 3.7dB/cm was realized in silicon slot waveguide for wavelengths near 1550nm. We also realized low propagation loss of 1dB/cm for silicon strip waveguides

    Hepatocellular carcinoma in Pakistan: where do we stand?

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    Context: From the 1970s till the mid 1990s, hepatitis B was the most common etiological factor for hepatocellular carcinoma (HCC) in Pakistan. Afterwards, a shift in HCC etiology was observed with a steady rise in hepatitis C virus (HCV) related HCC cases. HCV-3a, which is the most prevalent genotype, is also most frequent in HCV related HCC. There was an increase in the proportion of non-B non-C (NBNC) HCC cases as well, which might be attributed to an increase in non-alcoholic fatty liver disease. Evidence Acquisition: The age-standardized rate for HCC is 7.64/100 000 in males and 2.8/100 000 in females. Male to female ratio is 3.6:1. Usual age of presentation is in the fifth and sixth decade. Most patients present with advanced disease, as they are not in a regular surveillance program. This is more so for patients with NBNC chronic liver disease. As many sonologists in Pakistan are practicing without sufficient training to pick up early lesions, alpha-fetoprotein is still recommended to compliment ultrasound in the surveillance of HCC. Results: Majority of HCC patients present with nonresectable disease. Interventions such as transarterial chemoembolization, radiofrequency ablation, resection and chemotherapy including sorafenib are available in selected centers. Pakistan appears to be in an area of intermediate endemicity for HCC. There is a need for population based epidemiological studies to estimate the exact disease burden. Conclusions: Measures to prevent the spread of hepatitis C and B can slow down the epidemic rise in the incidence of HCC in the coming decades. There is a need to implement a proper surveillance program to identify HCC cases at an early stage

    Infections in children aged 6 months to 5 years treated with dupilumab in a placebo-controlled clinical trial of moderate-to-severe atopic dermatitis

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    Background: Patients with atopic dermatitis (AD), particularly infants and young children, are at greater risk of developing skin infections. In this study, we assessed infection rates in AD patients aged 6 months to 5 years treated with dupilumab. Methods: In LIBERTY AD PRESCHOOL, a double-blind, placebo-controlled, phase III clinical trial, children aged 6 months to 5 years with moderate-to-severe AD were randomized 1:1 to subcutaneous dupilumab or placebo, with concomitant low-potency topical corticosteroids, every 4 weeks for 16 weeks. Exposure-adjusted infection rates were used to compare treatment groups. Results: The analysis included 162 patients, of whom 83 received dupilumab and 79 received placebo. Total infection rates were not significantly different between the dupilumab and placebo groups (rate ratio [RR] 0.75, 95% CI 0.48–1.19; p = 0.223). Non-herpetic adjudicated skin infections and bacterial infections were significantly less frequent with dupilumab versus placebo (non-herpetic skin infections: RR 0.46, 95% CI 0.21–0.99; p = 0.047; bacterial infections: RR 0.09, 95% CI 0.01–0.67; p = 0.019), and the number of patients using systemic anti-infective medication was significantly lower in the dupilumab group (RR 0.52, 95% CI 0.30–0.89; p = 0.019). There were no significant differences in the number of herpetic infections between the dupilumab and placebo groups (RR 1.17, 95% CI 0.31–4.35; p = 0.817). The number of patients with two or more infection events was significantly higher in the placebo group (RR 0.29, 95% CI 0.12–0.68; p = 0.004), and no severe or serious infections (including eczema herpeticum) were observed among patients receiving dupilumab. Conclusions: These data suggest that dupilumab treatment in infants and children younger than 6 years with AD does not increase overall risk of infections and is associated with a reduced risk of bacterial and non-herpetic skin infections compared with placebo, resulting in a reduced need for anti-infective medication. Trial Registration: The trial was registered with ClinicalTrials.gov with ID number NCT03346434 on November 17, 2017. Infographic: [Figure not available: see fulltext.

    Field discharge calibration of head regulators, Mirpurkhas Sub-division, Jamrao Canal, Nara Circle, Sindh Province, Pakistan

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    Irrigation canals / Distributary canals / Flow control / Gates / Discharges / Calibrations / Measurement / Measuring instruments / Velocity / Pakistan / Sindh Province / Nara Circle / Jamrao Canal / Mirpurkhas

    Physical characteristics and operational performance of Mirpurkhas Sub-Division, Jamrao Canal Division, Nara Circle, Sindh Province, Pakistan

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    Irrigation programs / Irrigation canals / Canal regulation techniques / Flow control / Operations / Performance evaluation / History / Distributary canals / Calibrations / Gates / Discharges / Measurement / Hydraulics / Water allocation / Water lifting / Water distribution / Equity / Pakistan / Sindh Province / Nara Circle / Jamrao Canal / Mirpurkhas Distributary / Doso Dharoro Distributary / Kahu Visro Minor / Kahu Minor / Sanro Distributary / Bareji Distributary / Lakhakhi Distributary / Bhittaro Minor / Sangro Distributary / Daulatpur Minor / Bellaro Minor
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