641 research outputs found

    Analysis of Harvesting Energy from Mistuned Multiple Harvesters with and without Coupling

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    AbstractEnergy harvesting has received a lot of attention in the recent past. At present a single device does not harvested energy enough to power up an electronic sensors. In order to increase the power output multiple identical harvesters are used. When multiple harvesters are used, they bring in non-uniformity in their physical parameters due to variability during manufacturing or even during deployment. Therefore, ‘n’ numbers of harvesters do not necessary produce ‘n’ times the harvested power of a single device. The variability in parameters is less enough to be coined as mistuning. In this paper, an analysis of multiple energy harvesters is studied. The harvesters are assumed to show mistuning. The study is further extended to understand the effect of mechanical coupling between the harvesters. For simplification, pendulums are considered as the harvesters, with magnetic tip masses for the electromagnetic energy harvesting. Mistuning is achieved by varying the length of the pendulums. A generalized mathematical model for n coupled harvesters with mistuning is developed. Simulations are performed with the number of harvesters varying from 2 to 6 with ±1% non-repetitive mistuning in the lengths of the harvesters, and a comparison of the power harvested between mechanically coupled and uncoupled harvesters is presented

    Understanding the Global Problem of Drug Addiction is a Challenge for IDARS Scientists

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    IDARS is an acronym for the International Drug Abuse Research Society. Apart from our scientific and educational purposes, we communicate information to the general and scientific community about substance abuse and addiction science and treatment potential. Members of IDARS are research scientists and clinicians from around the world, with scheduled meetings across the globe. IDARS is developing a vibrant and exciting international mechanism not only for scientific interactions in the domain of addiction between countries but also ultimately as a resource for informing public policy across nations. Nonetheless, a lot more research needs to be done to better understand the neurobiological basis of drug addiction – A challenge for IDARS scientists

    Validation and reliability of the translated Malay version of the psychosocial impact of dental aesthetics questionnaire for adolescents

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    Background: This paper describes the cross-cultural adaptation of the Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) into Malay version (Malay PIDAQ), an oral health-related quality of life (OHRQoL) instrument specific for orthodontics for Malaysian adolescents between 12 and 17 years old. Methods: The PIDAQ was cross-culturally adapted into Malay version by forward-and backward-translation processes, followed by psychometric validations. After initial investigation of the conceptual suitability of the measure for the Malaysian population, the PIDAQ was translated into Malay, pilot tested and back translated into English. Psychometric properties were examined across two age groups (319 subjects aged 12-14 and 217 subjects aged 15-17 years old) for factor structure, internal consistency, reproducibility, discriminant and construct validity, criterion validity, and assessment of floor and ceiling effects. Results: Fit indices by confirmatory factor analysis showed good fit statistics (comparative fit index = 0.936, root-meansquare error of approximation = 0.064) and invariance across age groups. Internal consistency and reproducibility tests were satisfactory (Cronbach's alpha = 0.71-0.91; intra-class correlations = 0.72-0.89). Significant differences in Malay PIDAQ mean scores were observed between subjects with severe malocclusion and those with slight malocclusion based on a self-rated and an investigator-rated malocclusion index, for all subscales and all age groups (p < 0.05). Construct validity of the Malay PIDAQ subscales with those who rated themselves with excellent to poor dental appearance and those who felt they needed or did not need braces, showed significant associations for all age groups (p < 0.05). Criterion validity also showed significant association between the Malay PIDAQ scores with those with and without impact on daily activities attributed to malocclusion. There were no ceiling effects detected but floor effects were detected for the Aesthetic Concern subscale. Conclusion: The study has provided initial evidence for the validity and reliability of the Malay PIDAQ to assess the impact of malocclusion on the OHRQoL of 12-17 year old Malaysian adolescents

    Germination, physio-anatomical behavior, and productivity of wheat plants irrigated with magnetically treated seawater

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    Salinity is an abiotic stress that reduces the seed germination and productivity of wheat. The objective of this study was to assess the impact of irrigation with magnetically treated seawater on the germination, growth, certain physiological and anatomical parameters, and production attributes of wheat (Triticum aestivum L.) cv. Sakha 93 plants. Experiments were conducted in the Experimental Farm of the Faculty of Agriculture, Menoufia University, Egypt, during two consecutive winter seasons. Pot experiments involved ten treatments with non-magnetized and magnetized water with various degrees of salinity. Plant samples were taken 95 days after sowing. Irrigation with magnetically treated seawater was found to have beneficial effects on plant growth, water relations, biochemical characteristics, and yield components compared with untreated plants. The germination of wheat seeds increased 13% when treated with magnetic seawater. On the yield scale, the spike length was increased by 40% in season one, and 82% in season two when compared to the control, while the weight of 100 grains increased by 148% and 171%, in each season, respectively, when treated with magnetic water. The anatomical leaf and stem parameters of the plants were markedly improved by watering with magnetically treated seawater at 10 dS m−1 compared to the control. However, the leaf water deficit, transpiration rate, and abscisic acid content in the plant shoots decreased significantly (p < 0.05). The use of magnetically treated seawater of up to 7.5 dS m−1, instead of tap water, is recommended due to benefits to germination and seedling parameters, growth, yield, and physiological, chemical, and anatomical characteristics. In conclusion, magnetic treatment of seawater improved germination performance, growth, and yield of wheat under saline conditions

    Supporting international networks through platforms for standardised data collection-the European Registries for Rare Endocrine Conditions (EuRRECa) model

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    Rare endocrine pathology is manifested by either a deficiency or excess of one or more hormones. These conditions can be life-threatening and are almost universally associated with long-term morbidity. Understanding the aetiology of these conditions requires multicentre collaboration and expertise, most often across national boundaries, with the capacity for long-term follow-up. The EuRRECa (European Registries for Rare Endocrine Conditions) project (), funded by the EU Health Programme, aims to support the needs of the wider endocrine community by maximising the opportunity for collaboration between patients, health care professionals and researchers across Europe and beyond. At the heart of the EuRRECa collaboration is a Core Endocrine Registry that collects a core dataset for all rare endocrine conditions that are covered within Endo-ERN. The registry incorporates patient reported markers of clinical outcome and will signpost participants to high-quality, disease-specific registries. Furthermore, an electronic surveillance programme (e-REC) captures clinical activity and epidemiology for these rare conditions. EuRRECa receives guidance compliant with the highest ethical standards from Expert Working Groups that align with the Main Thematic Groups of Endo-ERN. Security, data quality and data governance are cornerstones of this platform. Clear policies that are acceptable to patients, researchers and industry for data governance coupled with widespread dissemination and knowledge exchange through closely affiliated stakeholders will ensure sustainability beyond the current lifetime of the project. This paper describes the infrastructure that has been developed, stakeholder involvement, the data fields that are captured within the registry and details on the process for using the platform.Diabetes mellitus: pathophysiological changes and therap

    Supporting international networks through platforms for standardised data collection—the European Registries for Rare Endocrine Conditions (EuRRECa) model

    Get PDF
    Rare endocrine pathology is manifested by either a deficiency or excess of one or more hormones. These conditions can be life-threatening and are almost universally associated with long-term morbidity. Understanding the aetiology of these conditions requires multicentre collaboration and expertise, most often across national boundaries, with the capacity for long-term follow-up. The EuRRECa (European Registries for Rare Endocrine Conditions) project (www.eurreca.net), funded by the EU Health Programme, aims to support the needs of the wider endocrine community by maximising the opportunity for collaboration between patients, health care professionals and researchers across Europe and beyond. At the heart of the EuRRECa collaboration is a Core Endocrine Registry that collects a core dataset for all rare endocrine conditions that are covered within Endo-ERN. The registry incorporates patient reported markers of clinical outcome and will signpost participants to high-quality, disease-specific registries. Furthermore, an electronic surveillance programme (e-REC) captures clinical activity and epidemiology for these rare conditions. EuRRECa receives guidance compliant with the highest ethical standards from Expert Working Groups that align with the Main Thematic Groups of Endo-ERN. Security, data quality and data governance are cornerstones of this platform. Clear policies that are acceptable to patients, researchers and industry for data governance coupled with widespread dissemination and knowledge exchange through closely affiliated stakeholders will ensure sustainability beyond the current lifetime of the project. This paper describes the infrastructure that has been developed, stakeholder involvement, the data fields that are captured within the registry and details on the process for using the platform

    On Some New Black String Solutions in Three Dimensions

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    We derive several new solutions in three-dimensional stringy gravity. The solutions are obtained with the help of string duality transformations. They represent stationary configurations with horizons, and are surrounded by (quasi) topologically massive Abelian gauge hair, in addition to the dilaton and the Kalb-Ramond axion. Our analysis suggests that there exists a more general family, where our solutions are special limits. Finally, we use the generating technique recently proposed by Garfinkle to construct a traveling wave on the extremal variant of one of our solutions.Comment: revtex, 38 pages including 3 figure
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