106 research outputs found

    A Review of Control Techniques Future Trends in Wind Energy Turbine Systems with Doubly Fed Induction Generators (DFIG)

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    تعتبر طاقة الرياح حاليا واحدة من أكثر مصادر الطاقة الخضراء النظيفة الملاءمة على نطاق واسع في العالم. تم تطوير العديد من مبادئ توربينات الرياح بستخدام  المولدات المختلفة لتحويل طاقة الرياح المتاحة إلى طاقة كهربائية. يعد نظام المولد الحثي ذي التغذية المزدوجة DFIG لتوربينات الرياح ذات السرعة المتغيرة نسبيا (VSWT) هو الأكثر ملاءمة لطاقة توربينات الرياح بسبب فوائده العديدة مقارنة بتوربينات الرياح ذات السرعة الثابتة نسبيا (FSWT). تقدم هذه الورقة مراجعة و مقارنة عن طاقة توربينات الرياح المختلفة وملخصًا قيمًا للعمل الأخير المتعلقة بأنظمة طاقة الرياح المختلفة (WECS) لنمذجة DFIG وأقصى نقطة طاقة MPP وأحدث نظام تحكم للتشغيل. ومن ناحية أخرى تم في الدراسة الحالية تقديم مقارنات ومناقشات بين توربينات الرياح المختلفة لتكون مفيدة للدراسات البحثية.Wind energy is currently widely regarded as one of the most favorable green clean sources of energy. Several wind turbine principles with various generator architectures have been evolved to exchange the available wind energy into electric power. The DFIG partial Variable-Speed Wind Turbine (VSWT) system is most proper for wind turbine energy because of its numerous benefits over Fixed-Speed Wind Turbines (FSWT). This paper introduces a comparative review of the different wind turbine conversion energy and a valuable summary of the recent work in the literature on different Wind Energy Conversion Systems (WECS) of a DFIG modeling, Maximum Power Point (MPP), and the latest control system for operation. On the other side, comparisons and discussions between different wind turbines have been presented in the current study to be beneficial for research studies

    Predicting the outcomes of traumatic brain injury using accurate and dynamic predictive model

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    Predictive models have been used widely to predict the diseases outcomes in health sector. These predictive models are emerged with new information and communication technologies. Traumatic brain injury has recognizes as a serious and crucial health problem all over the world. In order to predict brain injuries outcomes, the predictive models are still suffered with predictive performance. In this paper, we propose a new predictive model and traumatic brain injury predictive model to improve the predictive performance to classifying the disease predictions into different categories. These proposed predictive models support to develop the traumatic brain injury predictive model. A primary dataset is constructed which is based on approved set of features by the neurologist. The results of proposed model is indicated that model has achieved the best average ranking in terms of accuracy, sensitivity and specificity

    Rumex dentatus L. phenolics ameliorate hyperglycemia by modulating hepatic key enzymes of carbohydrate metabolism, oxidative stress and PPARγ in diabetic rats

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    Rumex dentatus L. is a flowering plant with promising therapeutic effects. This study investigated the antioxidant efficacy of phenolic compounds isolated from R. dentatus L. in vitro and by conducting density function theory (DFT) studies to explore the mechanisms of action. The antioxidant, anti-inflammatory and antidiabetic effects of polyphenols-rich R. dentatus extract (RDE) were investigated in type 2 diabetic rats. Phytochemical investigation of the aerial parts of R. dentatus resulted in the isolation of one new and seven known compounds isolated for the first time from this species. All isolated phenolics showed in vitro radical scavenging activity. The antioxidant activity of the compounds could be oriented by the hydrogen atom transfer and sequential proton loss electron transfer mechanisms in gas and water phases, respectively. In diabetic rats, RDE attenuated hyperglycemia, insulin resistance and liver injury and improved carbohydrate metabolism. RDE suppressed oxidative stress and inflammation and upregulated PPARγ. In silico molecular docking analysis revealed the binding affinity of the isolated compounds toward PPARγ. In conclusion, the computational calculations were correlated with the in vitro antioxidant activity of R. dentatus derived phenolics. R. dentatus attenuated hyperglycemia, liver injury, inflammation and oxidative stress, improved carbohydrate metabolism and upregulated PPARγ in diabetic ratsThis work has DGI Project no. CTQ2015-63997-C2, a generous allocation of computing time at the Centro de Computación Científica of the UAM is also acknowledge

    The headache under-response to treatment (HURT) questionnaire, an outcome measure to guide follow-up in primary care: development, psychometric evaluation and assessment of utility

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    Background: Headache disorders are both common and burdensome but, given the many people affected, provision of health care to all is challenging. Structured headache services based in primary care are the most efficient, equitable and cost-effective solution but place responsibility for managing most patients on health-care providers with limited training in headache care. The development of practical management aids for primary care is therefore a purpose of the Global Campaign against Headache. This manuscript presents an outcome measure, the Headache Under-Response to Treatment (HURT) questionnaire, describing its purpose, development, psychometric evaluation and assessment for clinical utility. The objective was a simple-to-use instrument that would both assess outcome and provide guidance to improving outcome, having utility across the range of headache disorders, across clinical settings and across countries and cultures. Methods: After literature review, an expert consensus group drawn from all six world regions formulated HURT through item development and item reduction using item-response theory. Using the American Migraine Prevalence and Prevention Study’s general-population respondent panel, two mailed surveys assessed the psychometric properties of HURT, comparing it with other instruments as external validators. Reliability was assessed in patients in two culturally-contrasting clinical settings: headache specialist centres in Europe (n = 159) and primary-care centres in Saudi Arabia (n = 40). Clinical utility was assessed in similar settings (Europe n = 201; Saudi Arabia n = 342). Results: The final instrument, an 8-item self-administered questionnaire, addressed headache frequency, disability, medication use and effect, patients’ perceptions of headache “control” and their understanding of their diagnoses. Psychometric evaluation revealed a two-factor model (headache frequency, disability and medication use; and medication efficacy and headache control), with scale properties apparently stable across disorders and correlating well and in the expected directions with external validators. The literature review found few instruments linking assessment to clinical advice or suggested actions: HURT appeared to fill this gap. In European specialist care, it showed utility as an outcome measure across headache disorders. In Saudi Arabian primary care, HURT (translated into Arabic) was reliable and responsive to clinical change. Conclusions: With demonstrated validity and clinical utility across disorders, cultures and settings, HURT is available for clinical and research purposes

    Diagnosis, prevalence estimation and burden measurement in population surveys of headache: presenting the HARDSHIP questionnaire

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    The global burden of headache is very large, but knowledge of it is far from complete and needs still to be gathered. Published population-based studies have used variable methodology, which has influenced findings and made comparisons difficult. The Global Campaign against Headache is undertaking initiatives to improve and standardize methods in use for cross-sectional studies. One requirement is for a survey instrument with proven cross-cultural validity. This report describes the development of such an instrument. Two of the authors developed the initial version, which was used with adaptations in population-based studies in China, Ethiopia, India, Nepal, Pakistan, Russia, Saudi Arabia, Zambia and 10 countries in the European Union. The resultant evolution of this instrument was reviewed by an expert consensus group drawn from all world regions. The final output was the Headache-Attributed Restriction, Disability, Social Handicap and Impaired Participation (HARDSHIP) questionnaire, designed for application by trained lay interviewers. HARDSHIP is a modular instrument incorporating demographic enquiry, diagnostic questions based on ICHD-3 beta criteria, and enquiries into each of the following as components of headache-attributed burden: symptom burden; health-care utilization; disability and productive time losses; impact on education, career and earnings; perception of control; interictal burden; overall individual burden; effects on relationships and family dynamics; effects on others, including household partner and children; quality of life; wellbeing; obesity as a comorbidity. HARDSHIP already has demonstrated validity and acceptability in multiple languages and cultures. Modules may be included or not, and others (eg, on additional comorbidities) added, according to the purpose of the study and resources (especially time) available

    Awareness, attitudes, and practices related to the swine influenza pandemic among the Saudi public

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    <p>Abstract</p> <p>Background</p> <p>During an infectious disease outbreak, it is critical to learn as much as possible about the concerns, knowledge, attitudes, and behavior of the public. Such information can be crucial to the improvement of communication efforts by public health officials and clinicians. The aim of this study was to identify awareness, attitudes, and practices related to influenza A (H1N1) among the Saudi public.</p> <p>Methods</p> <p>A cross-sectional study of 1,548 adult subjects recruited from various shopping malls in Riyadh and Jeddah was conducted. All of the subjects were interviewed using a questionnaire that tested their knowledge, attitudes, and use of precautionary measures in relation to the H1N1 influenza pandemic.</p> <p>Results</p> <p>More than half (54.3%, 840/1548) of the participants showed high concern, 43.7%(677/1548) showed a low level of knowledge, and 60.8%(941/1548) had taken minimal or no precautionary measures. After adjusting for other variables, education level was the only significant predictor of the level of concern (p < 0.001), while greater precautionary measures were taken by participants who were male (p < 0.001), older (p = 0.047), better educated (p = 0.04), and more knowledgeable (p < 0.001). More than one-third (38.3%) of participants were not convinced that the MOH reports about the disease were true, and only 16.1% of the participants reported receiving information from health providers.</p> <p>Conclusions</p> <p>High concern did not translate into a higher compliance with precautionary recommendations, possibly due to the low level of knowledge about the disease among the public. Frequent communication between physicians and the public is recommended to help dispel myths about the disease and to spread better information about the role that the public can play in limiting the spread of the disease.</p

    Mapping the terrain: A conceptual schema for a mental health medication support service in community pharmacy

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    Objective: Mental health–related problems pose a serious issue for primary care, and community pharmacy could make a significant contribution, but there is a dearth of information. Methods: This article reports synthesis of the literature on mental health interventions across a range of pharmacy models, and pharmacy services in contexts beyond mental health. To best inform the design of a community pharmacy medication support intervention for mental health consumers, the literature was reported as a conceptual schema and subsequent recommendations for development, implementation and evaluation of the service. A broad conceptualisation was taken in this review. In addition to mental health and community pharmacy literature, policy/initiatives, organisational culture and change management principles, and evaluative processes were reviewed. Key words were selected and literature reviews undertaken using EMBASE, PubMed, CINAHL and Web of Science. Results: Recommendations were made around: medication support intervention design, consumer recruitment, implementation in community pharmacy and evaluation. Surprisingly, there is a scarce literature relating to mental health interventions in community pharmacy. Even so, findings from other pharmacy models and broader medicines management for chronic illness can inform development of a medication support service for mental health consumers. Key learnings include the need to expand medicines management beyond adherence with respect to both intervention design and evaluation. Conclusion: The conceptual framework is grounded in the need for programmes to be embedded within pharmacies that are part of the health system as a whole

    Structured headache services as the solution to the ill-health burden of headache: 1. Rationale and description

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    In countries where headache services exist at all, their focus is usually on specialist (tertiary) care. This is clinically and economically inappropriate: most headache disorders can effectively and more efficiently (and at lower cost) be treated in educationally supported primary care. At the same time, compartmentalizing divisions between primary, secondary and tertiary care in many health-care systems create multiple inefficiencies, confronting patients attempting to navigate these levels (the “patient journey”) with perplexing obstacles. High demand for headache care, estimated here in a needs-assessment exercise, is the biggest of the challenges to reform. It is also the principal reason why reform is necessary. The structured headache services model presented here by experts from all world regions on behalf of the Global Campaign against Headache is the suggested health-care solution to headache. It develops and refines previous proposals, responding to the challenge of high demand by basing headache services in primary care, with two supporting arguments. First, only primary care can deliver headache services equitably to the large numbers of people needing it. Second, with educational supports, they can do so effectively to most of these people. The model calls for vertical integration between care levels (primary, secondary and tertiary), and protection of the more advanced levels for the minority of patients who need them. At the same time, it is amenable to horizontal integration with other care services. It is adaptable according to the broader national or regional health services in which headache services should be embedded. It is, according to evidence and argument presented, an efficient and cost-effective model, but these are claims to be tested in formal economic analyses
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