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The detection of a neutron star merger by the Advanced Laser Interferometer Gravitational-Wave Observatory and Advanced Virgo gravitational wave detectors, and the subsequent detection of an electromagnetic counterpart have opened a new era of transient astronomy. With upgrades to the Advanced Laser Interferometer Gravitational-Wave Observatory and Advanced Virgo detectors and new detectors coming online in Japan and India, neutron star mergers will be detected at a higher rate in the future, starting with the O3 observing run which will begin in early 2019. The detection of electromagnetic emission from these mergers provides vital information about merger parameters and allows independent measurement of the Hubble constant. The Australian Square Kilometre Array Pathfinder is expected to become fully operational in early 2019, and its 30 deg2 field of view will enable us to rapidly survey large areas of sky. In this work we explore prospects for detecting both prompt and long-term radio emission from neutron star mergers with Australian Square Kilometre Array Pathfinder and determine an observing strategy that optimises the use of telescope time. We investigate different strategies to tile the sky with telescope pointings in order to detect radio counterparts with limited observing time, using 475 simulated gravitational wave events. Our results show a significant improvement in observing efficiency when compared with a naïve strategy of covering the entire localisation above some confidence threshold, even when achieving the same total probability covered.
Artificial Neural Network based Nonlinear Autoregressive Model is designed to reconstruct and predict Forbush Decrease (FD) Data obtained from Izmiran, Russia. Result indicates that the model seems adequate for short term prediction of the FD data.
A new species, Gentiana arunii D.Maity, S.K.Dey, J.Ghosh & Midday, from alpine pasture in Sikkim Himalaya is described and illustrated, and placed in Gentiana section Chondrophyllae Bunge. The new species is compared morphologically with two related taxa, Gentiana glabriuscula T.N.Ho and Gentiana pluviarum W.W.Sm. subsp. subtilis (Harry Sm.) T.N.Ho.
The north eastern region (NER) of India receives a high amount of rainfall (2450 mm) both in terms of intensity and frequency. Most of the precipitation goes waste because of improper conservation measures and inadequate rainwater harvesting. Growing a second crop during winter (rabi) season on hill slopes and uplands without moisture conservation measure is almost impossible. A simple and very low-cost technique of in situ soil moisture conservation in maize (Zea mays L.)–toria (Brassica campestris L.) system has been developed using residue of preceding rainy season maize crop and mulching with locally available weed biomass Ambrosia artemisiifolia. Six residue mulching combinations tested were viz. control, Maize stalk cover (MSC), MSC + Ambrosia sp. 5 t/ha, MSC + Ambrosia sp. 10 t/ha, MSC + farmyard manure (FYM) 10 t/ha and MSC + Ambrosia sp. 5 t/ha + poultry manure 5 t/ha under zero tillage (ZT) and conventional tillage (CT) systems. Results showed that in situ residue retention of preceding maize crop along with green biomass of Ambrosia sp., applied before sowing of toria, maintained optimum soil moisture for good growth and higher yield of toria. The soil moisture content was consistently higher under residue mulched plots than that under control. All the residue mulching measures recorded higher crop yield for maize and toria than those observed under residue removal (control). The productivity of toria was enhanced by about 99%, only due to retention of MSC as mulch. Mulching with MSC + Ambrosia sp. 5 t/ha + poultry manure 5 t/ha recorded the highest seed yield of toria (four-year average: 641 kg/ha), which was 228% and 64% higher than no mulching (control) and MSC alone. MSC + FYM 10 t/ha (568.3 t/ha) and MSC + Ambrosia sp. 10 t/ha (517.4 t/ha) were found equally effective and produced significantly higher toria yield than that of control. MSC + Ambrosia mulch 10 t/ha gave the highest net returns and B:C ratio of the maize–toria system. The overall B:C ratios were better under ZT than CT. Thus, the study indicated that the integrated management of crop residues and weed biomass (Ambrosia sp.) under ZT created favourable soil moisture to support double cropping with high yield in hill eco-system of northeastern Indian Himalayas.
This study developed a fast and high throughput dot-blot technique to evaluate the presence of Entamoeba in stool samples (n = 643) followed by a PCR-based method to validate and differentiate the two species E. histolytica and E. dispar. The prevalence rate of the parasite has been detected in a cross-sectional study carried out in the population of the Eastern and Northern parts of India. Of the various demographic features, prevalence was highest in the monsoon season (P = 0·017), in the <15 years age group (P = 0·015). In HIV-positive individuals, the prevalence rate was significantly high (P = 0·008) in patients with a CD4 cell count <200 as well as in patients without antiretroviral therapy (ART) (P = 0·011). Our analysis further confirmed that risk factors such as toilet facilities, living conditions, hygienic practices, drinking water source, occupation and level of education are important predictors as they were found to contribute significantly in the prevalence of the parasite.
Faecal specimens of diarrhoea cases (n=2495, collected between November 2007 and October 2009) from Infectious Diseases and Beliaghata General (ID&BG) Hospital, Kolkata, India, were screened by RT–PCR using specific primers targeting region C of the capsid gene of noroviruses (NoVs) to determine the seasonal distribution and clinical characteristics of NoVs associated with diarrhoea. NoV infection was detected in 78 cases, mostly in children aged <2 years. In 22/78 positive cases, the virus was detected as the sole agent; others were as mixed infections with other enteric pathogens. Sequencing of NVGII strains showed clustering with GII.4 NoVs followed by GII.13 and GII.6 NoVs. Clinical characteristics of the diarrhoeic children and adults in Kolkata indicated that NoV infections were detected throughout the year and were associated with a mild degree of dehydration.
Over a 2-year period, 25 families comprising of 181 individuals of all ages were longitudinally observed for the excretion of Campylobacter species. Faecal samples were taken from all persons with diarrhoea. Specimens were also taken from apparently healthy individuals and from domestic animals living within the confines of the study families at monthly intervals.
The overall diarrhoea attack rate was 19 episodes per 100 person-years with peak incidence in the 1- to 4-year-old age group (76/100 person-years). Eight (11·5%) of the total episodes were campylobacter-associated and the overall rate of campylobacter positive diarrhoeal episodes were 2·2 per 100 person-years. Of the 1002 stool samples from healthy individuals 32 (3·2/100 samples) were positive for campylobacter. The organism was most frequently isolated from children under 1 year of age both during diarrhoeal episodes (11·5 per 100 person-years) and non-diarrhoeal (11·1 per 100 samples). Multiple infections in a family were rare. In 19·4% of the occasions one or more animals were campylobacter positive. However, only in 7·7% of these occasions was a human infection recorded within 1 month after the animal was found to be positive.
The study showed that the epidemiology of campylobacteriosis in this community was distinct compared to that observed in developed countries.
We have carried out a multi-wavelength study of the star forming region NGC 1893 to make a comprehensive exploration of the effects of massive stars on low mass star formation. Using deep optical U BV RI broad band, Hα narrow band photometry and slit-less spectroscopy along with archival data from the surveys such as 2MASS, MSX, IRAS and NVSS, we have studied the region to understand the star formation scenario in the region.
Dilute Magnetic Semiconductors (DMS) are a rare group of promising materials that utilize both the electronic charge - a characteristic of semiconductor materials - and the electronic spin - a characteristic of magnetic materials. Oxide based DMS show promise of ferromagnetism (FM) at room temperature. It has been found that doping metal oxides such as ZnO, TiO2, and In2O3 with magnetic ions such as Fe, Co, Mn, and Cr produces DMS, which exhibit FM above room temperature. In2O3, a transparent opto-electronic material, is an interesting prospect for spintronics due to a unique combination of magnetic, electrical, and optical properties. High quality thin films of rare earth magnetic gadolinium (Gd) doped oxide-based DMS materials have been grown by pulsed laser deposition (PLD) technique on various substrates such as single crystal of sapphire (001) and quartz under suitable growth conditions of substrate temperature and oxygen pressure in the PLD chamber. The effect of rare earth magnetic doping on the structural and electro - magnetic properties of these films has been studied using Raman Spectroscopy, X-Ray Diffraction, Scanning Electron Microscopy, and Magneto - Transport. An X- ray diffraction study reveals that these films are single phase and highly oriented. Characteristic Raman peaks typical of indium oxide are observed at 496 and 627 cm−1. We have observed high magnetoresistance (∼18 %) at a relatively small field of 1.3 Tesla for the films with 10 % gadolinium. A detailed study of temperature and magnetic field dependent resistivity, magnetoresistance, and Hall Effect will be presented.
Soil organic carbon storage encompasses both soil productivity and environmental capabilities. The influence of fertilizer (nitrogen and phosphorus) levels (0 NP, 0·5 NP, 1·0 NP (recommended standard) or 1·5 NP) on total system productivity, sustainable yield index and soil organic carbon storage in Vertisols (Typic Haplustert) under groundnut and fallow-based cropping systems were examined in a field experiment over 6 years. The aim was to identify a system that provided an acceptable balance between total system productivity and soil organic carbon restoration. The experiment comprised two rainy season crops (groundnut or fallow) and five post-rainy season crops (wheat, mustard, chickpea, sunflower or summer groundnut), each post-rainy season crop with four levels of NP fertilizer. The total system productivity was 130% higher in the groundnut-based than in the fallow-based system and was in the order: groundnut–groundnut>groundnut–chickpea>groundnut–wheat>groundnut–mustard>groundnut–sunflower. The sustainable yield index was highest in the groundnut–groundnut system. The gross C input was relatively higher in the groundnut-based system but the C loss rate was greater. The amount of residue needed per ha per year to compensate for loss of soil organic carbon was estimated to be 4·3 t in the fallow-based and 7·6 t in the groundnut–based cropping system. Though the total system productivity was greater in groundnut–groundnut and groundnut–chickpea systems, soil organic carbon declined. The groundnut–wheat system contributed more C, particularly root biomass C, than other systems, improved the restoration of soil organic carbon and maintained total system productivity. It was concluded that current fertilizer recommendations are adequate for maintaining yields in groundnut-based systems but the addition of crop residues at regular intervals along with fertilizer is necessary to maintain restoration of soil organic carbon.
The purpose of this paper is to report the experimental results of boron doping on 60-80 micron size diamond particles using Field Enhanced Diffusion with Optical activation (FEDOA) [1-5]. Diamond is a wide band gap material with unique combinations of optical, thermal, mechanical and electronic properties that can be useful for a number of applications including optoelectronic applications and micro sensor technology. The incorporation of boron into diamond has been proven to change its electrical properties and convert the diamond from insulator to a p-type semiconductor . A promising technique for incorporation of impurities into diamond is FEDOA. FEDOA drives impurities into single crystalline diamond material and we have used this method in this study [5-7]. FEDOA uses a combination of thermal diffusion with bias plus thermal ionization and optical ionization I simultaneously. A modified version of FEDOA was implemented for the diffusion of boron in natural diamond type II/a powder of size 60-80 microns (Figure 1). The diamond powder was obtained from Microdiamant and has 99.9% purity. The boron powder used in the experiment was amorphous, 325 mesh 90 %(Assay), Mg (5%) nominal obtained from AESAR. A ratio of 3:1 Boron-Diamond mixture was used for the doping process. A heating element and a diamond-boron powder mixture holder were designed and incorporated in the FEDOA system. Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS) were used to study the diamond-doped morphology and identify impurities. Boron and hydrogen concentration results in the doped samples were studied using Prompt Gamma Neutron Activation Analysis (PGNAA) at the University of Missouri Research Reactor (MURR). Raman analysis of the treated samples was done as part of this work. The experimental results and analysis show that the samples were doped with boron. It was also found that samples with high boron concentration exhibited a high electrical conductivity. This work presents additional evidence that boron can be diffused into natural diamond powders. It also demonstrates that the FEDOA diffusion process is not only a powerful technique for the diffusion of impurities into wide band-gap materials in the form of single crystal plates, polycrystalline plate but also in a powder form with the modified FEDOA process.
By incorporating optical fiber based devices into woven and non-woven fabrics, one can distribute these devices across large areas. In this work, novel fiber optic devices with nanofunctionality are developed by incorporating metallic and semiconducting films and nanoparticles inside the optical fibers. This is accomplished by first depositing the material of interest on the tip of the optical fiber, then overcoating the fiber with a protective layer of silicon dioxide before fusing this structure to an optical fiber. This results in a continuous fiber that can be woven, or placed into nonwoven textiles. In this study the incorporation of gold nanoparticles and vanadium oxide compounds into the core of optical fibers and an in-line Fabry-Perot sensor using these techniques are described.
Genomic variability within the sequences of VP1/2A junction among polioviruses from across the globe has revealed the existence of several endemic genotypes and their epidemiological inter-relationships; but such data on Indian isolates are scanty. The present work was intended to ascertain the persistence and transmission pattern of different genotypes of wild type 1 polioviruses circulating in India. Forty-eight wild type 1 poliovirus isolates obtained from different parts of India during 1996–8 were subjected to RT–PCR and nucleotide sequencing using M13 tailed primers. A 293 base pair region was amplified and sequenced for genetic variation study. Considering the 15% divergence of the sequences from Sabin 1, the isolates from six different states of India confirmed a single dominant genotype 4. Phylogenetic analysis revealed the circulation and active inter-state transmission of many genetically distinct strains of wild poliovirus type 1 belonging to genotype 4. This warrants the need for insisting on more efficient surveillance mechanisms so as to assess the impact of an extensive pulse polio immunization programme in India.
Electrotextiles have attracted increasing attention in recent years. The combinations of textile structures that are lightweight, flexible, conformable, and strong, with electronics have aroused keen interest from many disciplines. With technological innovations appearing in both textile and electronics, integration of these has started giving benefits. Innovations like the sensate liner, soft switches and smart composites have found many applications in sports, healthcare, military, aerospace engineering, civil engineering and many other fields. The purpose of this paper is to provide an overview of various electrotextile products available and explain their functionality. Additionally, the paper provides a review of future electrotextile products, which are in the developmental phase, and the challenges that need to be addressed by researchers and industry.
This paper describes the development of woven electrical circuits, which are formed by interlacing conducting and non-conducting threads into a woven fabric. Conductive threads in these electrical networks are arranged and woven such that they follow desired electrical circuit designs. Electronic devices can be attached to these electrical networks, which can serve as flexible circuit boards. In these woven circuits, an efficient transfer of current from one conductive yarn to an orthogonal one is achieved by the formation of an effective electrical interconnect at the point of intersection of these yarns. Formation of woven conductive networks also involves disconnect formation or cutting of conductive yarns at certain specified points. Different methods and processes were identified and applied in order to form interconnects and disconnects at specified points of these fabrics. Efficacy of these interconnects was evaluated by DC resistance and AC Signal measurements. The results of these evaluations are reported. The conductive threads woven into these fabric-based circuits were also evaluated for signal integrity issues.
Weaving, knitting or placing electronic circuits within a textile matrix offer exciting possibilities for large-scale conformal circuits where the circuit dimensions can be measured on the scale of yards instead of inches. However, compared with conventional printed circuit board circuits, the textile manufacturing process and the electrical/mechanical properties of the fibers used in making the textile place unusual constraints on the electrical performance of textile circuits. In the case of distributed sensors connected via an electronic fabric, signal attenuation and the ability to form reliable interconnections are major challenges. To explore these challenges we have woven and knitted a variety of electrical transmission lines and optical fibers in fabrics to analyze their performance. The formation of interconnects and disconnects between conductors woven in textiles is also discussed, and a passive acoustic array is described as a possible electronic textile application.
Electronic textiles offer possibilities for producing large-area sensors circuits on conformal substrates. To demonstrate this concept, a 5×4 element acoustic array was produced on a 3m × 1m fabric substrate. In the course of fabricating the acoustic array a variety of production issues were identified that impacted the performance of the prototype when experimental tests were carried out with this prototype acoustic array. Fabric-based acoustic array design and production, along with design issues related to scaling an acoustic array to handle larger numbers of microphones on large-area fabrics, are the focus of this paper.
Large scale (~0.6 sq deg) mapping of the giant Galactic star
forming complex W 51 has been carried out simultaneously in two
trans-IRAS far infrared (FIR) bands centered at ~200 and 130
μm using the TIFR 100 cm balloon borne FIR telescope.
The choice of the bands is motivated by the aim of studying the emission
from the cold dust (T< 30 K) component.
These maps with ~1' spatial resolution,
show extended emission with
structures. Nearly identical beams in the two bands have enabled us to
reliably determine the distribution of dust temperature T(130/200), and optical
depth τ200, in the central region of the W 51 complex.
A total of 25 discrete sources have been extracted from the 200 μm
map, of which 8 have been associated with IRAS PSC sources and 16
with sources in HIRES processed IRAS maps at 100, 60, 25 & 12 μm
The values of the emissivity power law index β in FIR,
show wide variation among these sources.
Cavitation caused by superplastic straining of a fine-grained Al-Mg-Mn-Cu alloy under uniaxial tension has been systematically evaluated. Tensile tests were conducted in the strain-rate range of 10−4s−1 to 10−2s−1 and in the temperature range of 450°C to 550°C. Measurements of the number and size of cavities were made by image analysis through optical microscopy on tested specimens. With increasing imposed strain, the cavity population density increases. Cavity growth has been found to be primarily due to the plastic deformation of the matrix. These results are characterized by the total volume fraction of cavities which is found to increase exponentially with strain. However, the dependencies of cavity volume fraction on strain-rate and temperature are not straightforward and the notion of just a few large cavities controlling the total cavity volume is not always true. Attempts to explain these complex dependencies have been carried out based on the concepts of debonding between the matrix and non-deformable particles, the continuous nucleation of new cavities, and plasticity-based cavity growth for large cavities.