1,203 research outputs found

    Non-Destructive Evaluation—A Pivotal Technology for Qualification of Composite Aircraft Structures

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    Tremendous advances in composite materials and a deeper understanding of their behavior have been responsible for the increased use of composites in the development of advanced, new generation civil and military aircraft. Composites play an important role in any aircraft development programme and are strong contenders to their metal counterparts due to their significant contributions towards improving strength, stiffness, fatigue properties & weight reduction. As materials, structural design & processing have evolved, strong emphasis is placed on effective & reliable damage detection, durability and damage tolerance. As a consequence, Non-destructive Evaluation (NDE) has also undergone significant advances towards meeting the growing demands of quality assurance. Advanced Composites Division (ACD) of National Aerospace Laboratories (NAL), has been involved in the development of composite structures for both civil and military aircraft for over a decade and a half. Innovative composite processing methods like co-curing/co-bonding have been successfully employed to realize airworthy structures. The role of NDE in the development of these structures has been critical and not limited to damage detection alone. On several occasions, NDE has provided valuable inputs towards improving design and process parameters. In-spite of the complexity of the structures, stringent quality requirements and tight delivery schedules, NDE has been successful in certifying these composite structures for airworthiness. This paper discusses the implementation of key NDE techniques like ultrasonics, radiography, acoustic emission and thermography for reliable flaw detection, characterization and quality assurance of composite aircraft structures

    Small Carnivores of Biligiri Rangaswamy Temple Tiger Reserve, Karnataka, India

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    During the present study in Biligiri Rangaswamy Temple Tiger Reserve (BRT), nine species of small carnivores viz., Jungle Cat Felis chaus, Rusty-spotted Cat Prionalilurus rubiginosus, Leopard Cat Prionailurus bengalensis, Small Indian Civet Viverricula indica, Asian Palm Civet Paradoxurus hermaphroditus, Striped-necked Mongoose Herpestes vitticollis, Ruddy Mongoose Herpestes smithii, Common Mongoose Herpestes edwardsii and Smooth-coated Otter Lutrogale perspicillata, were recorded using camera-trapping technique, transect walks, and night surveys. Vegetation type strongly influences the presence and abundance of each species. The most sightings of small carnivores occurred in dry deciduous forests. Among all the species, the Asian Palm Civet was the most abundant and was followed by the small Indian Civet. Compared to many other forests or regions in India, the sight records of the Rusty-spotted Cat were relatively higher in BRT. Although we were unable to use statistical methods to search for higher levels of interdependencies between forest types and small carnivore abundance, our study sheds light on patterns of small carnivore distribution in this unique habitat which bridges the Western Ghats and the Eastern Ghats

    Decline of suitable habitats and conservation of the endangered lion-tailed macaque: land-cover change at a proposed protected area in Sirsi– Honnavara, Western Ghats, India

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    Habitat fragmentation, loss of habitat and other anthropogenic activities have caused a population decline in many species, caused restriction in their distribution or even led to their local extinction. We attempted to understand the impact of such pressures on the newly identified and possibly the largest population of the endangered lion-tailed macaque, Macaca silenus in the Reserve Forests of Sirsi and Honnavara, Karnataka, using a temporal series of satellite images. Classified images showed a major increase in open area with a rapid decline in vegetation cover of about 11.5% in the wet evergreen forests over the last decade, amounting to a loss at the rate of 1.9% per year. We thus consider habitat protection and restoration of evergreen forest as the top priority along with the enforcement of conservation steps, including legal action against encroachment, extraction of timber and further fragmentation, to protect this critically important habitat of the lion-tailed macaque

    Removal of various contaminants from water by renewable lignocellulose-derived biosorbents: a comprehensive and critical review

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    © 2019, © 2019 Taylor & Francis Group, LLC. Contaminants in water bodies cause potential health risks for humans and great environmental threats. Therefore, the development and exploration of low-cost, promising adsorbents to remove contaminants from water resources as a sustainable option is one focus of the scientific community. Here, we conducted a critical review regarding the application of pristine and modified/treated biosorbents derived from leaves for the removal of various contaminants. These include potentially toxic cationic and oxyanionic metal ions, radioactive metal ions, rare earth elements, organic cationic and anionic dyes, phosphate, ammonium, and fluoride from water media. Similar to lignocellulose-based biosorbents, leaf-based biosorbents exhibit a low specific surface area and total pore volume but have abundant surface functional groups, high concentrations of light metals, and a high net surface charge density. The maximum adsorption capacity of biosorbents strongly depends on the operation conditions, experiment types, and adsorbate nature. The absorption mechanism of contaminants onto biosorbents is complex; therefore, typical experiments used to identify the primary mechanism of the adsorption of contaminants onto biosorbents were thoroughly discussed. It was concluded that byproduct leaves are renewable, biodegradable, and promising biosorbents which have the potential to be used as a low-cost green alternative to commercial activated carbon for effective removal of various contaminants from the water environment in the real-scale plants

    Traditional birth attendants lack basic information on HIV and safe delivery practices in rural Mysore, India

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    <p>Abstract</p> <p>Background</p> <p>There is little research on HIV awareness and practices of traditional birth attendants (TBA) in India. This study investigated knowledge and attitudes among rural TBA in Karnataka as part of a project examining how traditional birth attendants could be integrated into prevention-of-mother-to-child transmission of HIV (PMTCT) programs in India.</p> <p>Methods</p> <p>A cross-sectional survey was conducted between March 2008 and January 2009 among TBA in 144 villages in Mysore <it>Taluk</it>, Karnataka. Following informed consent, TBA underwent an interviewer-administered questionnaire in the local language of <it>Kannada </it>on practices and knowledge around birthing and HIV/PMTCT.</p> <p>Results</p> <p>Of the 417 TBA surveyed, the median age was 52 years and 96% were Hindus. A majority (324, 77.7%) had no formal schooling, 88 (21.1%) had up to 7 years and 5 (1%) had more than 7 yrs of education. Only 51 of the 417 TBA (12%) reported hearing about HIV/AIDS. Of those who had heard about HIV/AIDS, only 36 (72%) correctly reported that the virus could be spread from mother to child; 37 (74%) identified unprotected sex as a mode of transmission; and 26 (51%) correctly said healthy looking people could spread HIV. Just 22 (44%) knew that infected mothers could lower the risk of transmitting the virus to their infants. An overwhelming majority of TBA (401, 96.2%) did not provide antenatal care to their clients. Over half (254, 61%) said they would refer the woman to a hospital if she bled before delivery, and only 53 (13%) felt referral was necessary if excessive bleeding occurred after birth.</p> <p>Conclusions</p> <p>Traditional birth attendants will continue to play an important role in maternal child health in India for the foreseeable future. This study demonstrates that a majority of TBA lack basic information about HIV/AIDS and safe delivery practices. Given the ongoing shortage of skilled birth attendance in rural areas, more studies are needed to examine whether TBA should be trained and integrated into PMTCT and maternal child health programs in India.</p

    Validation of Differentially Expressed Immune Biomarkers in Latent and Active Tuberculosis by Real-Time PCR

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    Tuberculosis (TB) remains a major global threat and diagnosis of active TB ((ATB) both extra-pulmonary (EPTB), pulmonary (PTB)) and latent TB (LTBI) infection remains challenging, particularly in high-burden countries which still rely heavily on conventional methods. Although molecular diagnostic methods are available, e.g., Cepheid GeneXpert, they are not universally available in all high TB burden countries. There is intense focus on immune biomarkers for use in TB diagnosis, which could provide alternative low-cost, rapid diagnostic solutions. In our previous gene expression studies, we identified peripheral blood leukocyte (PBL) mRNA biomarkers in a non-human primate TB aerosol-challenge model. Here, we describe a study to further validate select mRNA biomarkers from this prior study in new cohorts of patients and controls, as a prerequisite for further development. Whole blood mRNA was purified from ATB patients recruited in the UK and India, LTBI and two groups of controls from the UK (i) a low TB incidence region (CNTRLA) and (ii) individuals variably-domiciled in the UK and Asia ((CNTRLB), the latter TB high incidence regions). Seventy-two mRNA biomarker gene targets were analyzed by qPCR using the Roche Lightcycler 480 qPCR platform and data analyzed using GeneSpring™ 14.9 bioinformatics software. Differential expression of fifty-three biomarkers was confirmed between MTB infected, LTBI groups and controls, seventeen of which were significant using analysis of variance (ANOVA): CALCOCO2, CD52, GBP1, GBP2, GBP5, HLA-B, IFIT3, IFITM3, IRF1, LOC400759 (GBP1P1), NCF1C, PF4V1, SAMD9L, S100A11, TAF10, TAPBP, and TRIM25. These were analyzed using receiver operating characteristic (ROC) curve analysis. Single biomarkers and biomarker combinations were further assessed using simple arithmetic algorithms. Minimal combination biomarker panels were delineated for primary diagnosis of ATB (both PTB and EPTB), LTBI and identifying LTBI individuals at high risk of progression which showed good performance characteristics. These were assessed for suitability for progression against the standards for new TB diagnostic tests delineated in the published World Health Organization (WHO) technology product profiles (TPPs)

    An investigation into the roles of chlorides and sulphate salts on the performance of low salinity injection in sandstone reservoirs : experimental approach

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    Numerous studies have been carried out to ascertain the mechanisms of low salinity and smart water flooding technique for improved oil recovery. Focus were often on brine composition and, specifically the cationic content in sandstone reservoirs. Given the importance of the salt composition and concentration, tweaking the active ions which are responsible for the fluids-rock equilibrium will bring into effect numerous mechanisms of displacement which have been extensively debated. This experimental study, however, was carried out to evaluate the extent of the roles of chloride and sulphate-based brines in improved oil recovery. To carry this out, 70,000 ppm sulphates and chloride-based brines were prepared to simulate formation water and 5,000ppm brines of the same species as low salinity displacement fluids. Core flooding process was used to simulate the displacement of oil by using four (4) native sandstones core samples, obtained from Burgan oil field in Kuwait, at operating conditions of 1500 psig and 50oC. The core samples were injected with 70,000 ppm chloride and sulphates and subsequently flooded with the 5,000 ppm counterparts in a forced imbibition process. Separate evaluations of chloride and sulphate-based brines were carried out to investigate the displacement efficiencies of each brine species. The results showed that the in both high and low salinity displacement tests, the SO4 brine presented better recovery of up to 89% of the initial oil saturation (Soi). Several mechanisms of displacement were observed to be responsible for improved recovery during SO4 brine displacement. IFT measurement experiments also confirmed that there was reduction in IFT at test conditions between SO4 brine and oil and visual inspection of the effluent showed a degree emulsification of oil and brines. Changes in pH were observed in the low salinity flooding and negligible changes were noticed in the high salinity floods. These results provide an insight into the roles of chloride and sulphate ions in the design of smart “designer” water and low salinity injection scenarios
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