A Power Quality Improvement for Microgrid Inverter Operated in Grid Connected and Grid Disconnected Modes

The renewable energy based distributed generators (DGs) will plays a dominant role in electricity production. A micro grid consists of clusters of load and distributed generators that operate as a single controllable system. The interconnection of the DG to the utility/grid through power electronic converters has raised concern about safe operation and protection of the equipments. The main objective of this paper is too focused on the power quality improvement in micro grid. In the distributed power system, the increased infiltration of nonlinear loads and power electronic interfaced distribution generation systems creates power quality issues such as voltage unbalance, frequency regulation and harmonic elimination

Visible and infrared photocurrent enhancement in a graphene-silicon Schottky photodetector through surface-states and electric field engineering

The design of efficient graphene-silicon (GSi) Schottky junction photodetectors requires detailed understanding of the spatial origin of the photoresponse. Scanning-photocurrent-microscopy (SPM) studies have been carried out in the visible wavelengths regions only, in which the response due to silicon is dominant. Here we present comparative SPM studies in the visible ($\lambda$ = 633nm) and infrared ($\lambda$ = 1550nm) wavelength regions for a number of GSi Schottky junction photodetector architectures, revealing the photoresponse mechanisms for silicon and graphene dominated responses, respectively, and demonstrating the influence of electrostatics on the device performance. Local electric field enhancement at the graphene edges leads to a more than ten-fold increased photoresponse compared to the bulk of the graphene-silicon junction. Intentional design and patterning of such graphene edges is demonstrated as an efficient strategy to increase the overall photoresponse of the devices. Complementary simulations and modeling illuminate observed effects and highlight the importance of considering graphene's shape and pattern and device geometry in the device design

Maternal and perinatal outcome of Evan’s syndrome: a 5 years study in a tertiary care centre

Background: Evans syndrome is a rare autoimmune disorder characterized by simultaneous or sequential presence of a positive antiglobulin test, autoimmune haemolytic anemia (AIHA), and immune thrombocytopenia (ITP). It is characterised by frequent exacerbations and remissions within a chronic course. It was first described by Robert Evans in 1951.  Incidence of AIHA is 1 per 75 - 80,000 and ITP is 5.5 /100000 per general adult population.  Incidence of Evans syndrome is 1.8% to 10% of patients with ITP. Objective was to study the maternal and perinatal outcome of women with Evans syndrome (E).Methods: About 4 antenatal mothers were identified with Evans syndrome at St. Johns medical college and hospital, Bengaluru during the study period of 5 years from July 2013-July 2017. They were followed up during their antenatal, intra natal and postnatal period and outcomes were studied. All patients included in the study fulfilled the criteria for Evans syndrome.Results: There were 4 cases of Evans syndrome, with a total number of deliveries of 11859, during this 5 year study. Incidence was 0.09 per 1000 births. All patients presented with bleeding manifestations ranging from mucosal haemorrhage to subarachnoid haemorrhage (SAH) at the time of diagnosis. All patients were on treatment with either 1st or 2nd line of management with corticosteroids/ azathioprine. None had bleeding during pregnancy after the initiation of treatment. Patients had antenatal complications like preeclampsia 25%, IUGR 25%, oligohydraminos 50%, IUD 25%. 2 patients received platelet transfusions intrapartum. None had intrapartum or postpartum haemorrhage. There were no maternal and neonatal mortality.Conclusions: Evans syndrome in pregnancy is a rare condition and requires multi disciplinary approach involving specialists from obstetrics, neonatology, and hematology. Close maternal and fetal surveillance and management during pregnancy is essential to increase the possibility of a favourable pregnancy outcome in these women

Neutrino hierarchy from CP-blind observables with high density magnetized detectors

High density magnetized detectors are well suited to exploit the outstanding purity and intensities of novel neutrino sources like Neutrino Factories and Beta Beams. They can also provide independent measurements of leptonic mixing parameters through the observation of atmospheric muon-neutrinos. In this paper, we discuss the combination of these observables from a multi-kton iron detector and a high energy Beta Beam; in particular, we demonstrate that even with moderate detector granularities the neutrino mass hierarchy can be determined for $\theta_{13}$ values greater than 4$^\circ$.Comment: 16 pages, 7 figures. Added a new section discussing systematic errors (sec 5.2); sec.5.1 and 4 have been extended. Version to appear in EPJ

First CNGS events detected by LVD

The CERN Neutrino to Gran Sasso (CNGS) project aims to produce a high energy, wide band $\nu_{\mu}$ beam at CERN and send it toward the INFN Gran Sasso National Laboratory (LNGS), 732 km away. Its main goal is the observation of the $\nu_{\tau}$ appearance, through neutrino flavour oscillation. The beam started its operation in August 2006 for about 12 days: a total amount of $7.6~10^{17}$ protons were delivered to the target. The LVD detector, installed in hall A of the LNGS and mainly dedicated to the study of supernova neutrinos, was fully operating during the whole CNGS running time. A total number of 569 events were detected in coincidence with the beam spill time. This is in good agreement with the expected number of events from Montecarlo simulations.Comment: Accepted for publication by the European Physical Journal C ; 7 pages, 11 figure

On-line recognition of supernova neutrino bursts in the LVD detector

In this paper we show the capabilities of the Large Volume Detector (INFN Gran Sasso National Laboratory) to identify a neutrino burst associated to a supernova explosion, in the absence of an "external trigger", e.g., an optical observation. We describe how the detector trigger and event selection have been optimized for this purpose, and we detail the algorithm used for the on-line burst recognition. The on-line sensitivity of the detector is defined and discussed in terms of supernova distance and electron anti-neutrino intensity at the source.Comment: Accepted for pubblication on Astroparticle Physics. 13 pages, 10 figure

Dark Matter Results from 100 Live Days of XENON100 Data

We present results from the direct search for dark matter with the XENON100 detector, installed underground at the Laboratori Nazionali del Gran Sasso of INFN, Italy. XENON100 is a two-phase time projection chamber with a 62 kg liquid xenon target. Interaction vertex reconstruction in three dimensions with millimeter precision allows to select only the innermost 48 kg as ultra-low background fiducial target. In 100.9 live days of data, acquired between January and June 2010, no evidence for dark matter is found. Three candidate events were observed in a pre-defined signal region with an expected background of 1.8 +/- 0.6 events. This leads to the most stringent limit on dark matter interactions today, excluding spin-independent elastic WIMP-nucleon scattering cross-sections above 7.0x10^-45 cm^2 for a WIMP mass of 50 GeV/c^2 at 90% confidence level.Comment: 5 pages, 5 figures; matches accepted versio

Implications on Inelastic Dark Matter from 100 Live Days of XENON100 Data

The XENON100 experiment has recently completed a dark matter run with 100.9 live-days of data, taken from January to June 2010. Events in a 48kg fiducial volume in the energy range between 8.4 and 44.6 keVnr have been analyzed. A total of three events have been found in the predefined signal region, compatible with the background prediction of (1.8 \pm 0.6) events. Based on this analysis we present limits on the WIMP-nucleon cross section for inelastic dark matter. With the present data we are able to rule out the explanation for the observed DAMA/LIBRA modulation as being due to inelastic dark matter scattering off iodine at a 90% confidence level.Comment: 3 pages, 3 figure