93 research outputs found

    Energy Efficient Photovoltaic Systems using Thermoelectric Cooling System

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    Dual thermoelectric-photovoltaic (TE-PV) systems are a type of solar energy technology that combines two different technologies to generate electricity by concentrating solar radiation. These systems use a solar concentrator to focus sunlight onto a photovoltaic cell and a thermoelectric generator. The aim of this paper is to develop a dual thermoelectric-photovoltaic system with a water-cooled heat sink to generate electricity from concentrated solar radiation through Fresnel lenses.In addition, the detailed design for the components that will be integrated into an experimental prototype of the dual system on a laboratory scale is carried out and its functionality is determined. Finally, its functionality is evaluated and achieved an estimated maximum power of 1.5 Watts

    Foetal arrhythmias: an enigma of the missed beats

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    Background: The synchronised depolarization and repolarisation of the atria and ventricles is achieved by specialised cardiac cells that generate an electrical impulse and propagate it along the conducting system in the myocardial tissue, leading to rhythmic activity of the atria and ventricles. Abnormalities of these rhythms lead to foetal arrhythmia.Methods: A retrospective observational study was conducted in a tertiary care hospital over period of one year to study the course and perinatal outcome of women with foetal arrhythmias.Results: The confinement in the study period was N=4302, of which 207(4.81%) women had foetal congenital malformations. Among them 21(0.48%) women had foetal cardiovascular abnormalities and 6(0.14%) women had foetal arrhythmias. There were two cases of maternal primary Sjogrens syndrome: one with foetal 2nddegree atrioventricular (AV) heart block with 2:1 AV conduction and another with foetal 3rd degree or complete heart block. Others were a case of Atrial premature contractions with compensatory pause, a case of Supraventricular tachycardia, one case of sinus tachycardia with non-immune hydrops and a case of foetal bradyarrhythmia with regular ectopic beats in a case of complex congenital heart disease. The course of these pregnancies, treatment options and perinatal outcome was studied.Conclusions: Foetal echocardiography and Doppler are effective tools for detection and monitoring of foetal arrhythmias. Early and correct diagnoses of arrhythmias help in management of foetal arrhythmias and multidisciplinary team-based approach gives optimum treatment results

    Cooperative Opportunistic Large Array Approach for Cognitive Radio Networks

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    Anaesthetic Management of a Patient with Gullain Barre Syndrome Posted for Emergency Caesarean Section: A Case Report

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    Gullain Barre Syndrome (GBS) is an acute inflammatory demyelinating polyradiculopathy of rare occurrence in pregnancy. We report a case of a 36 weeks pregnant patient posted for emergency Caesarean section for foetal distress. At 28weeks of pregnancy the patient was diagnosed with GBS for which she was intubated and was on mechanical ventilation for 19 days. Subsequently she was extubated and discharged after 36 days. During this period, she received treatment with intravenous immunoglobulins and plasmapheresis. The patient continued to have weakness of both lower limbs and bladder incontinence prior to surgery. General anaesthesia was administered to the patient keeping in view the autonomic system involvement in the disease and presence of foetal distress. The intraoperative course was smooth and patient was extubated uneventfully. Keywords: Gullain Barre Syndrome, Pregnancy, Autonomic dysfunction, General anaesthesia, Emergency caesarean sectio

    IPAC Image Processing and Data Archiving for the Palomar Transient Factory

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    The Palomar Transient Factory (PTF) is a multiepochal robotic survey of the northern sky that acquires data for the scientific study of transient and variable astrophysical phenomena. The camera and telescope provide for wide-field imaging in optical bands. In the five years of operation since first light on 2008 December 13, images taken with Mould-R and SDSS-g′ camera filters have been routinely acquired on a nightly basis (weather permitting), and two different Hα filters were installed in 2011 May (656 and 663 nm). The PTF image-processing and data-archival program at the Infrared Processing and Analysis Center (IPAC) is tailored to receive and reduce the data, and, from it, generate and preserve astrometrically and photometrically calibrated images, extracted source catalogs, and co-added reference images. Relational databases have been deployed to track these products in operations and the data archive. The fully automated system has benefited by lessons learned from past IPAC projects and comprises advantageous features that are potentially incorporable into other ground-based observatories. Both off-the-shelf and in-house software have been utilized for economy and rapid development. The PTF data archive is curated by the NASA/IPAC Infrared Science Archive (IRSA). A state-of-the-art custom Web interface has been deployed for downloading the raw images, processed images, and source catalogs from IRSA. Access to PTF data products is currently limited to an initial public data release (M81, M44, M42, SDSS Stripe 82, and the Kepler Survey Field). It is the intent of the PTF collaboration to release the full PTF data archive when sufficient funding becomes available

    Nevirapine Resistance and Breast-Milk HIV Transmission: Effects of Single and Extended-Dose Nevirapine Prophylaxis in Subtype C HIV-Infected Infants

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    Daily nevirapine (NVP) prophylaxis to HIV-exposed infants significantly reduces breast-milk HIV transmission. We assessed NVP-resistance in Indian infants enrolled in the "six-week extended-dose nevirapine" (SWEN) trial who received single-dose NVP (SD-NVP) or SWEN for prevention of breast-milk HIV transmission but who also acquired subtype C HIV infection during the first year of life.Standard population sequencing and cloning for viral subpopulations present at > or =5% frequency were used to determine HIV genotypes from 94% of the 79 infected Indian infants studied. Timing of infection was defined based on when an infant's blood sample first tested positive for HIV DNA. SWEN-exposed infants diagnosed with HIV by six weeks of age had a significantly higher prevalence of NVP-resistance than those who received SD-NVP, by both standard population sequencing (92% of 12 vs. 38% of 29; p = 0.002) and low frequency clonal analysis (92% of 12 vs. 59% of 29; p = 0.06). Likelihood of infection with NVP-resistant HIV through breast-milk among infants infected after age six weeks was substantial, but prevalence of NVP-resistance did not differ among SWEN or SD-NVP exposed infants by standard population sequencing (15% of 13 vs. 15% of 20; p = 1.00) and clonal analysis (31% of 13 vs. 40% of 20; p = 0.72). Types of NVP-resistance mutations and patterns of persistence at one year of age were similar between the two groups. NVP-resistance mutations did differ by timing of HIV infection; the Y181C variant was predominant among infants diagnosed in the first six weeks of life, compared to Y188C/H during late breast-milk transmission.Use of SWEN to prevent breast-milk HIV transmission carries a high likelihood of resistance if infection occurs in the first six weeks of life. Moreover, there was a continued risk of transmission of NVP-resistant HIV through breastfeeding during the first year of life, but did not differ between SD-NVP and SWEN groups. As with SD-NVP, the value of preventing HIV infection in a large number of infants should be considered alongside the high risk of resistance associated with extended NVP prophylaxis.ClinicalTrials.gov NCT00061321

    Association of Vegetable and Animal Flesh Intake with Inflammation in Pregnant Women from India

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    In pregnant women, studies are lacking on the relationship of vegetable and animal flesh (poultry, red meat and seafood) intake with inflammation, especially in low- and middle-income countries. We conducted a cohort study of pregnant women receiving antenatal care at BJ Medical College in Pune, India. The dietary intake of pregnant women was queried in the third trimester using a validated food frequency questionnaire. Twelve inflammatory markers were measured in plasma samples using immunoassays. Only 12% of the study population were vegetarians, although animal flesh intake levels were lower compared to Western populations. In multivariable models, higher intakes of total vegetables were associated with lower levels of the T-helper (Th) 17 cytokine interleukin (IL)-17a (p = 0.03) and the monocyte/macrophage activation marker soluble CD163 (sCD163) (p = 0.02). Additionally, higher intakes of poultry were negatively associated with intestinal fatty-acid binding protein (I-FABP) levels (p = 0.01), a marker of intestinal barrier dysfunction and Th2 cytokine IL-13 (p = 0.03), and higher seafood was associated with lower IL-13 (p = 0.005). Our data from pregnant women in India suggest that a higher quality diet emphasizing vegetables and with some animal flesh is associated with lower inflammation. Future studies should confirm these findings and test if modulating vegetables and animal flesh intake could impact specific aspects of immunity and perinatal health

    The Zwicky Transient Facility: Data Processing, Products, and Archive

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    The Zwicky Transient Facility (ZTF) is a new robotic time-domain survey currently in progress using the Palomar 48-inch Schmidt Telescope. ZTF uses a 47 square degree field with a 600 megapixel camera to scan the entire northern visible sky at rates of ~3760 square degrees/hour to median depths of g ~ 20.8 and r ~ 20.6 mag (AB, 5sigma in 30 sec). We describe the Science Data System that is housed at IPAC, Caltech. This comprises the data-processing pipelines, alert production system, data archive, and user interfaces for accessing and analyzing the products. The realtime pipeline employs a novel image-differencing algorithm, optimized for the detection of point source transient events. These events are vetted for reliability using a machine-learned classifier and combined with contextual information to generate data-rich alert packets. The packets become available for distribution typically within 13 minutes (95th percentile) of observation. Detected events are also linked to generate candidate moving-object tracks using a novel algorithm. Objects that move fast enough to streak in the individual exposures are also extracted and vetted. The reconstructed astrometric accuracy per science image with respect to Gaia is typically 45 to 85 milliarcsec. This is the RMS per axis on the sky for sources extracted with photometric S/N >= 10. The derived photometric precision (repeatability) at bright unsaturated fluxes varies between 8 and 25 millimag. Photometric calibration accuracy with respect to Pan-STARRS1 is generally better than 2%. The products support a broad range of scientific applications: fast and young supernovae, rare flux transients, variable stars, eclipsing binaries, variability from active galactic nuclei, counterparts to gravitational wave sources, a more complete census of Type Ia supernovae, and Solar System objects.Comment: 30 pages, 16 figures, Published in PASP Focus Issue on the Zwicky Transient Facility (doi: 10.1088/1538-3873/aae8ac
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