58,002 research outputs found
Optimal allocation of FACTS devices in distribution networks using Imperialist Competitive Algorithm
Copyright © 2005-2015 Praise Worthy Prize. The publisher granted a permission to the author to archive this article in BURA.FACTS devices are used for controlling the voltage, stability, power flow and security of transmission lines. Imperialist Competitive is a recently developed optimization technique, used widely in power systems. This paper presents an approach to finding the optimal location and size of FACTS devices in a distribution network using the Imperialist Competitive technique. IEEE 30-bus system is used as a case study. The results show the advantages of the Imperialist Competitive technique over the conventional approaches. © 2013 Praise Worthy Prize S.r.l. - All rights reserved
Monitoring of power factor for induction machines using estimation techniques
Power factor is a significant element in power systems which is defined as the angle difference between voltages and currents that produces power fluctuation between sources and loads. Since, 40-50% of consumption of electrical power in industry is induction machines which are inductive loads, monitoring of the power factor is necessary in order to protect systems. To monitor the power factor on induction machines, it would require both voltage and current waveforms measurement in order to apply the displacement method which require equipments. In this paper, we present a mathematical method using Kriging to determine the operating power factor for an induction machine. Estimation of the operating power factor would be effectively implemented for under load detection and compensation for improving the power quality. Experimental results will be indicated to substantiate the feasibility of the proposed methods
Improved BPSO for optimal PMU placement
Optimal phasor measurement unit (PMU) placement involves the process of minimizing the number of PMU needed while ensuring entire power system network completely observable. This paper presents the improved binary particle swarm (IBPSO) method that converges faster and also manage to maximize the measurement redundancy compared to the existing BPSO method. This method is applied to IEEE-30 bus system for the case of considering zero-injection bus and its effectiveness is verified by the simulation results done by using MATLAB software
Short circuit study of fixed speed wind turbines with STATCOM in distribution networks
The increased penetration of wind farm in distribution networks has brought changes in the performance of the whole system. Such disadvantages when connecting one of these distributed generation sources is reduced voltage and power stability of the AC network. This phenomena can cause the connected electricity consumers to suffer from disturbances. This paper investigates the use of a static synchronous compensator (STATCOM) to improve the short circuit current contribution in the network which will include balanced and unbalanced faults. The wind farm is equipped with fixed-speed wind turbines driving squirrel-cage induction generators. The IEEE 30-bus distribution test system is used to see the performance of the system under distribution level. Simulation studies are carried out in the DIgSILENT software
Quality of Life Following Massive Weight Loss and Body Contouring Surgery: an Exploratory Study.
Reconstructive surgery is a major growth intervention for body improvement, enhancing appearance and psychological well-being following massive weight loss. The psychosocial benefits include greater capacity for social networking, lower scores of body uneasiness, body image satisfaction, improved mental well-being and physical function. However little collective evidence exists regarding the impact of body contouring on patients Quality of Life (QoL) and there is a lack of systematic review and randomised controlled trials (RCTs) with a scarcity of high level evidence. The purpose of this exploratory study was to explore the QoL perceptions, experiences and outcomes of patients who have undergone body contouring following significant weight loss and to explore the relevance and potential utility of the Obesity Psychosocial State Questionnaire (OPSQ) as a valuable QoL outcomes measuring tool for use in clinical research. Data were collected in a community setting in the south of England via digitally recorded semi-structured interviews with twenty participants (18 women and 2 men), who also self-completed the Obesity Psychosocial State Questionnaire (OBSQ). Medical notes were reviewed retrospectively to gather data about body mass index (BMI), co-morbidities, eating profiles/lifestyle, uptake of bariatric surgery and type/number of body contouring procedures undergone. A thematic approach was adopted to analyse the interviews and medical record data, supported by Nvivo7 qualitative software, and a statistical approach to analyse the questionnaire data, supported by Statistical Analysis Software. The results provide unique glimpses of the body contouring interventions for empowering and facilitating a ‘transformation’, a ‘new identity’, a ‘new start’ in life, improved physical function, greater body image satisfaction, a stronger sense of well-being and an improved quality of life. A few of the participants who reported that their weight gain was powered by childhood traumas (abuse, neglect, abandonment) continued to struggle for ‘normality’, with fragile eating control and addictive traits. Eating disordered trauma survivors mentioned post traumatic flashbacks and underlying conflicts that triggered powerlessness and emotional eating. The emotional flooding with psychological and body related memories did not appear to be fully processed or released, despite counselling and binge eating programmes. The participants also confirmed the value of the OBSQ, whilst highlighting its limited set of three questions on feelings of self-efficacy towards eating habits. The study findings show that body contouring optimises quality of life with significant improvement in physical function, body image, mental health and psychosocial function. Further research is warranted to extent the scope of the findings within a sample drawn from multiple treatment centres. This would valuably: • Explore gender, ethnic and cultural variables, important to optimising quality of life. • Clarify distinguishing features between short and long-term QoL outcomes. • Lead to the development of national policy and guidelines on reconstructive ‘body contouring’ surgery following massive weight loss, in line with the call from the British Association for Plastic, Reconstructive and Aesthetic Surgeons (BAPRAS) A future multi-centre collaborative study could employ the OBSQ, supplemented by an additional tool to explore factors that influence eating habits such as the three factor eating questionnaire (such as the TFEQ-R1 21 Scale). Such research could enhance understanding of quality of life and long-term weight management
Complementary and Alternative Medicine (CAM) Therapies in the Treatment of Meniere's Syndrome: Illness Narratives
Colonnade interior, glass wall, from above, depicting brise-soleil; The building today commonly referred to as the Old City Hall was the building that served as Ottawa's city hall from 1958 to 2000. Today it is officially known as 111 Sussex Drive and is owned by the Federal Government of Canada. The building is located on Green Island at the point where the Rideau River empties into the Ottawa. The International Style building was opened on August 2, 1958 by Princess Margaret as a member of the Canadian Royal Family. It is noted for the first building in Ottawa to be fully air conditioned. It was designed by John Bland of the firm of Rother, Bland and Trudeau and is considered one of the most important International Style buildings in Canada. Winning the Massey Medal for design in 1959, modifications were made by Moshe Safdie in 1992-1993. Today the building mainly houses foreign affairs employees. Source: Wikipedia; http://en.wikipedia.org/wiki/Main_Page (accessed 1/10/2008
Exploring the evidence base for acupuncture in the treatment of Meniere’s Syndrome — A systematic review
Meniere’s syndrome is a long-term, progressive disease that damages the balance and hearing
parts of the inner ear. To address the paucity of information on which evidence-based treatment
decisions should be made, a systematic review of acupuncture for Meniere’s syndrome was
undertaken. The method used was a systematic review of English and Chinese literature, from
six databases for randomized, non-randomized and observational studies. All studies were
critically appraised and a narrative approach to data synthesis was adopted. Twenty-seven
studies were included in this review (9 in English and 18 in Chinese languages): three randomized
controlled trials, three non-randomized controlled studies and four pre-test, post-test
designs. All but one of the studies was conducted in China. The studies covered body acupuncture,
ear acupuncture, scalp acupuncture, fluid acupuncture point injection and moxibustion.
The studies were of varying quality. The weight of evidence, across all study types, is of beneficial
effect from acupuncture, for those in an acute phase or those who have had Meniere’s
syndrome for a number of years. The review reinforces the importance of searching for studies
from English and Chinese literature. The transferability of the findings from China to a
Western context needs confirmation. Further research is also needed to clarify questions
around the appropriate frequency and number of treatment/courses of acupuncture. The
weight of evidence suggests a potential benefit of acupuncture for persons with Meniere’s
disease, including those in an acute phase and reinforces the importance of searching for
published studies in the Chinese language
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