331 research outputs found

    Modelling interfacial coupling in thin film magnetic exchange springs at finite temperature

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    This is the final version of the article. Available from the American Institute of Physics via the DOI in this record.We report a numerical study that demonstrates the interface layer between a soft and hard magnetic phase, the exchange transition layer, is the dominant factor that influences the magnetization reversal process at room temperature and long measurement times. It is found that the exchange transition layer thickness affects the magnetization reversal and the coupling of a bi-layer system by lowering the switching field and changing the angle dependent magnetization reversal. We show that the change in angle dependence of reversal is due to an increased incoherency in the lateral spin behavior. Changing the value of exchange coupling in the exchange transition layer affects only the angle dependent behavior and does not lower the switching field. © 2013 AIP Publishing LLC.We would like to thank the EPSRC for financial support under Grant Nos. EP/G032440/1 and EP/G032300/1, the WWTF Project MA09-029 and the Royal Society UF080837

    Grain boundaries in granular materials-A fundamental limit for thermal stability

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    This is the final version of the article. Available from the American Institute of Physics via the DOI in this record.We show that thermal-stability and the associated switching field in well segregated, nanoscale granular materials is explained by grain boundary and interface effects. Grain boundaries pose a fundamental limit on scaling rooted in their chemical and morphological structure, while exchange interactions across interfaces cause the switching to deviate from the expected coherent Stoner-Wohlfarth behaviour. Measurements and simulations of CoCrPt-systems show a clear shift in applied field angle behaviour, arising from exchange-coupling between magnetic-phases, while the quantitative switching field can only be explained by a transition layer surrounding the grains. These results are potentially significant for Heat-Assisted-Magnetic Recording and Bit-Patterned-Media Recording. © 2013 AIP Publishing LLC.We would like to thank the EPSRC for financial support under Grants No. EP/G032440/1, EP/G032300/1, the WWTF Project MA09-029 and the Royal Society

    CLASSIFICATION AND ASSESSMENT OF THE LAND USE – LAND COVER CHANGES IN JODHPUR CITY USING REMOTE SENSING TECHNOLOGIES

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    Land Use – Land Cover (LULC) classification mapping is an important tool for management of natural resources of an area. The remote sensing technology in recent times has been used in monitoring the changing patterns of land use-land cover. The aim of the study is to monitor the LULC changes in Jodhpur city over the period 1990–2018. Satellite imagery of Landsat 8 OLI (June, 2018) & Landsat TM (Oct, 1990) were used for classification analysis. Supervised classification-maximum likelihood algorithm is used in ENVI software to detect land use land cover changes. Five LULC categories were used, namely- urban area, mining area, vegetation, water bodies and other area (Rock outcrops and barren land). The LULC classified maps of two different periods i.e. 2018 and 1990 were generated on 1 : 50,000 scale. The accuracy assessment method was used to measure the accuracy of classified maps. This study shall be of good assistance to the town planners of Jodhpur city for the purpose of the sustainable development as per the master plan 2031

    Mapping age- and sex-specific HIV prevalence in adults in sub-Saharan Africa, 2000–2018

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    Publisher Copyright: © 2022, The Author(s).Background: Human immunodeficiency virus and acquired immune deficiency syndrome (HIV/AIDS) is still among the leading causes of disease burden and mortality in sub-Saharan Africa (SSA), and the world is not on track to meet targets set for ending the epidemic by the Joint United Nations Programme on HIV/AIDS (UNAIDS) and the United Nations Sustainable Development Goals (SDGs). Precise HIV burden information is critical for effective geographic and epidemiological targeting of prevention and treatment interventions. Age- and sex-specific HIV prevalence estimates are widely available at the national level, and region-wide local estimates were recently published for adults overall. We add further dimensionality to previous analyses by estimating HIV prevalence at local scales, stratified into sex-specific 5-year age groups for adults ages 15–59 years across SSA. Methods: We analyzed data from 91 seroprevalence surveys and sentinel surveillance among antenatal care clinic (ANC) attendees using model-based geostatistical methods to produce estimates of HIV prevalence across 43 countries in SSA, from years 2000 to 2018, at a 5 × 5-km resolution and presented among second administrative level (typically districts or counties) units. Results: We found substantial variation in HIV prevalence across localities, ages, and sexes that have been masked in earlier analyses. Within-country variation in prevalence in 2018 was a median 3.5 times greater across ages and sexes, compared to for all adults combined. We note large within-district prevalence differences between age groups: for men, 50% of districts displayed at least a 14-fold difference between age groups with the highest and lowest prevalence, and at least a 9-fold difference for women. Prevalence trends also varied over time; between 2000 and 2018, 70% of all districts saw a reduction in prevalence greater than five percentage points in at least one sex and age group. Meanwhile, over 30% of all districts saw at least a five percentage point prevalence increase in one or more sex and age group. Conclusions: As the HIV epidemic persists and evolves in SSA, geographic and demographic shifts in prevention and treatment efforts are necessary. These estimates offer epidemiologically informative detail to better guide more targeted interventions, vital for combating HIV in SSA.Peer reviewe

    Engaging with sustainability issues in metropolitan Chennai : city report

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    Chennai is the largest metropolitan city in South India (8.7 million in 2011) and the provincial capital of the large state of Tamil Nadu (population 72 million in 2011). Before that, under British rule, the city was the capital of the Madras Presidency, and was known as Madras until 1996, when the name was officially changed to Chennai. Located on the east coast of India, on the Bay of Bengal, sea trade has been an important aspect of the regional economy since at least the colonial period. Still today, the city combines political functions with economic command functions for both manufacturing and services, reflecting the region's diversified economy. The Chennai metropolitan area has witnessed strong growth over the last 20 years in automobile manufacturing, software services, hardware manufacturing, healthcare and financial services (CDP 2009). However, it should be noted that only 30% of total employment in the city takes place in the formal sector i.e., is covered by contracts and labour laws, the remaining 70% falls in the informal sector. This underscores the importance of small and micro enterprises and self-employment for providing goods, services and livelihoods in the local economy

    Germplasm characterization, association and clustering for salinity and waterlogging tolerance in bread wheat (Triticum aestivum)

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    A study was conducted for characterizing germplasm, estimating interrelationship of traits and clustering of wheat genotypes in five environments covering salinity, waterlogging and neutral soils using, 100 elite but diverse genotypes with eight checks of bread wheat (Triticum aestivum L.). These genotypes were planted under five distinct environments during rabi 2009-10 under augmented design in four blocks wherein each check was repeated twice. The genetic variance, correlation coefficients and cluster analysis were carried out for assessment of lines through seven metric traits, namely, plant stand, plant height, days to heading, days to maturity, tillers/meter, 1000-grain weight and grain yield. Analysis of variance revealed wide variability for most of the traits under study. The phenotypic coefficient of variation (PCV) was high for tillers/meter and grain yield, while high heritability coupled with high genetic advance were found for tillers/meter, 1000-grain weight and grain yield under all five environments. At phenotypic level, positive and significant correlation coefficients revealed that under all the normal and stressed environments used here, grain yield is directly influenced by plant stand, tillers/meter and thousand grain weights. Significant and positive correlations were estimated between tillers/meter (r = 0.31 to 0.66), and 1000 grain weight (r = 0.24 to 0.61) with grain yield under all five environments. Under waterlogged conditions there were significant negative correlations of plant height to grain yield (r = –0.38 to –0.39) across two sites. These results, thereby suggests that yield improvement in bread wheat could be possible by emphasizing these traits through selection in these diverse environments. On the basis of D2 values of pooled data, 108 genotypes were grouped into four clusters. In all, only 26 lines were found common in cluster III under two waterlogging environments (Faizabad and Karnal), while only 15 lines were common in cluster I under non waterlogging (Faizabad, CSSRI and DWR) conditions. These results indicate different constraints exist in waterlogged and non-waterlogged condition at these sites. Genetic diversity available for these traits may be utilized for yield improvement in bread wheat under different soil conditions through planned hybridization and selection in target environments

    Parental psychological distress during pregnancy and the risk of childhood lower lung function and asthma: a population-based prospective cohort study

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    Background Although maternal psychological distress during pregnancy is associated with increased risks of respiratory morbidity in preschool children, it is unknown whether this association persists into later childhood. Objective To examine the association between parental psychological distress during pregnancy and lung function and asthma in children of school age. Methods This study of 4231 children was embedded in a population-based prospective cohort. Parental psychological distress was assessed by the Brief Symptom Inventory during and 3 years after pregnancy, and in mothers also at 2 and 6 months after pregnancy. At age 10 years, lung function was obtained by spirometry and asthma by questionnaire. Results The prevalence of asthma was 5.9%. Maternal overall psychological distress during pregnancy was associated with a lower forced vital capacity (FVC) (z-score difference −0.10 (95% CI −0.20 to –0.01) per 1-unit increase), maternal depressive symptoms during pregnancy with a lower forced expiratory volume in the first second (FEV1 ) and FVC (−0.13 (95% CI −0.24 to –0.01) and −0.13 (95% CI −0.24 to –0.02) when using clinical cut-offs) in their children. All maternal psychological distress measures during pregnancy were associated with an increased risk of asthma (range OR: 1.46 (95% CI 1.12 to 1.90) to 1.91 (95% CI 1.26 to 2.91)). Additional adjustment for paternal psychological distress during pregnancy and parental psychological distress after pregnancy did not materially change the associations. Paternal psychological distress during pregnancy was not associated with childhood respiratory morbidity. Conclusion Maternal, but not paternal, psychological distress during pregnancy is associated with an increased risk of asthma and partly lower lung function in children. This suggests intrauterine programming for the risk of later-life respirator

    Parental psychological distress during pregnancy and the risk of childhood lower lung function and asthma: a population-based prospective cohort study

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    Background Although maternal psychological distress during pregnancy is associated with increased risks of respiratory morbidity in preschool children, it is unknown whether this association persists into later childhood. Objective To examine the association between parental psychological distress during pregnancy and lung function and asthma in children of school age. Methods This study of 4231 children was embedded in a population-based prospective cohort. Parental psychological distress was assessed by the Brief Symptom Inventory during and 3 years after pregnancy, and in mothers also at 2 and 6 months after pregnancy. At age 10 years, lung function was obtained by spirometry and asthma by questionnaire. Results The prevalence of asthma was 5.9%. Maternal overall psychological distress during pregnancy was associated with a lower forced vital capacity (FVC) (z-score difference −0.10 (95% CI −0.20 to –0.01) per 1-unit increase), maternal depressive symptoms during pregnancy with a lower forced expiratory volume in the first second (FEV1 ) and FVC (−0.13 (95% CI −0.24 to –0.01) and −0.13 (95% CI −0.24 to –0.02) when using clinical cut-offs) in their children. All maternal psychological distress measures during pregnancy were associated with an increased risk of asthma (range OR: 1.46 (95% CI 1.12 to 1.90) to 1.91 (95% CI 1.26 to 2.91)). Additional adjustment for paternal psychological distress during pregnancy and parental psychological distress after pregnancy did not materially change the associations. Paternal psychological distress during pregnancy was not associated with childhood respiratory morbidity. Conclusion Maternal, but not paternal, psychological distress during pregnancy is associated with an increased risk of asthma and partly lower lung function in children. This suggests intrauterine programming for the risk of later-life respiratory disease

    Fog computing security: a review of current applications and security solutions

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    Fog computing is a new paradigm that extends the Cloud platform model by providing computing resources on the edges of a network. It can be described as a cloud-like platform having similar data, computation, storage and application services, but is fundamentally different in that it is decentralized. In addition, Fog systems are capable of processing large amounts of data locally, operate on-premise, are fully portable, and can be installed on heterogeneous hardware. These features make the Fog platform highly suitable for time and location-sensitive applications. For example, Internet of Things (IoT) devices are required to quickly process a large amount of data. This wide range of functionality driven applications intensifies many security issues regarding data, virtualization, segregation, network, malware and monitoring. This paper surveys existing literature on Fog computing applications to identify common security gaps. Similar technologies like Edge computing, Cloudlets and Micro-data centres have also been included to provide a holistic review process. The majority of Fog applications are motivated by the desire for functionality and end-user requirements, while the security aspects are often ignored or considered as an afterthought. This paper also determines the impact of those security issues and possible solutions, providing future security-relevant directions to those responsible for designing, developing, and maintaining Fog systems
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