Dynamic Modeling and Simulation of a STATCOM/SMES Compensator in Power Systems

The advent of Flexible AC Transmission Systems (FACTS) is giving rise to a new family of electronic equipment emerging to controlling and optimizing the performance of power system, e.g. STATCOM. Static synchronous compensator (STATCOM) is one of the most widely used FACTS devices. This paper presents the integration of STATCOM coupled with superconducting magnetic energy storage (SMES) device in order to provide power oscillation damping in power systems. The additional of energy storage allows the combined compensator to exchange both reactive and active power with the ac network and also capability of the STATCOM is enhanced. This paper describes the structure and characteristics of STATCOM/SMES. In addition, using a proper control scheme, STATCOM/SMES is tested on an IEEE 3-bus system and more effective performance of the presented STATCOM/SMES compensator is evaluated with alone STATCOM through the dynamic simulation by using PSCAD/EMTDC software

Dynamic Modeling and Simulation of a STATCOM/SMES Compensator in Power Systems

The advent of Flexible AC Transmission Systems (FACTS) is giving rise to a new family of electronic equipment emerging to controlling and optimizing the performance of power system, e.g. STATCOM. Static synchronous compensator (STATCOM) is one of the most widely used FACTS devices. This paper presents the integration of STATCOM coupled with superconducting magnetic energy storage (SMES) device in order to provide power oscillation damping in power systems. The additional of energy storage allows the combined compensator to exchange both reactive and active power with the ac network and also capability of the STATCOM is enhanced. This paper describes the structure and characteristics of STATCOM/SMES. In addition, using a proper control scheme, STATCOM/SMES is tested on an IEEE 3-bus system and more effective performance of the presented STATCOM/SMES compensator is evaluated with alone STATCOM through the dynamic simulation by using PSCAD/EMTDC software

Effects of Experiment Location and Orbiter Attitude on the Residual Acceleration On-Board STS-73 (USML-2)

A knowledge of the quasi-steady acceleration environment on the NASA Space Shuttle Orbiter is of particular importance for materials processing experiments which are limited by slow diffusive processes. The quasi-steady (less than 1 HZ) acceleration environment on STS-73 (USML-2) was measured using the Orbital Acceleration Research Experiment (OARE) accelerometer. One of the facilities flown on USML-2 was the Crystal Growth Furnace (CGF), which was used by several Principal Investigators (PIS) to grow crystals. In this paper the OARE data mapped to the sample melt location within this furnace is presented. The ratio of the axial to radial components of the quasi-steady acceleration at the melt site is presented. Effects of Orbiter attitude on the acceleration data is discussed

School health assessment tools: A systematic review of measurement in primary schools

Background. This systematic review aimed to investigate the psychometric properties of the school health's assessment tools in primary schools through COSMIN Risk of Bias checklist. We examined the studies that have addressed the measurement properties of school-health instruments to give a clear overview of the quality of all available tools measuring school health in primary schools. This systematic review was registered in PROPERO with the Registration ID: CRD42020158158. Method. Databases of EBSCOhost, PubMed, ProQuest, Wily, PROSPERO, and OpenGrey were systematically searched without any time limitation to find all full-text English journal articles studied at least one of the COSMIN checklist measurement properties of a school-health assessment tool in primary schools. The instruments should be constructed based on a school health model. The eligible studies were assessed by COSMIN Risk of Bias checklist to report their quality of methodology for each measurement property and for the whole study by rating high, moderate or low quality. Results. At the final screening just seven studies remained for review. Four studies were tool development, three of them were rated as ''adequate'' and the other study as ''very good''; five studies examined the content validity, three of them were appraised as ''very good'', and the two remaining as ''inadequate''. All seven studies measured structural validity, three of them were evaluated as ''very good'', three other were scored as ''adequate'', and the last study as ''inadequate''. All the seven studies investigated the internal consistency, five of them were assessed as ''very good'', one was rated as ''doubtful'', and the last one as ''inadequate''. Just one study examined the cross-cultural validity and was rated as ''adequate''. Finally, all seven studies measured reliability, two of them were rated as ''very good'' and the rest five studies were appraised as ''doubtful''. All rating was based on COSMIN checklist criteria for quality of measurement properties assessment. Conclusion. The number of studies addressing school health assessment tools was very low and therefore not sufficient. Hence, there is a serious need to investigate. Copyright © 2020 Kazemitabar et al

Treatment of osteochondral lesions of the talus: a systematic review

The aim of this study was to summarize all eligible studies to compare the effectiveness of treatment strategies for osteochondral defects (OCD) of the talus. Electronic databases from January 1966 to December 2006 were systematically screened. The proportion of the patient population treated successfully was noted, and percentages were calculated. For each treatment strategy, study size weighted success rates were calculated. Fifty-two studies described the results of 65 treatment groups of treatment strategies for OCD of the talus. One randomized clinical trial was identified. Seven studies described the results of non-operative treatment, 4 of excision, 13 of excision and curettage, 18 of excision, curettage and bone marrow stimulation (BMS), 4 of an autogenous bone graft, 2 of transmalleolar drilling (TMD), 9 of osteochondral transplantation (OATS), 4 of autologous chondrocyte implantation (ACI), 3 of retrograde drilling and 1 of fixation. OATS, BMS and ACI scored success rates of 87, 85 and 76%, respectively. Retrograde drilling and fixation scored 88 and 89%, respectively. Together with the newer techniques OATS and ACI, BMS was identified as an effective treatment strategy for OCD of the talus. Because of the relatively high cost of ACI and the knee morbidity seen in OATS, we conclude that BMS is the treatment of choice for primary osteochondral talar lesions. However, due to great diversity in the articles and variability in treatment results, no definitive conclusions can be drawn. Further sufficiently powered, randomized clinical trials with uniform methodology and validated outcome measures should be initiated to compare the outcome of surgical strategies for OCD of the talus

Volume • 5 • Number • 2 • 2012 Page 73 SORPTION OF NANOFILLED VERSUS OTHER CONVENTIONAL COMPOSITES

Abstract Since composite water sorption can result in expansion of the restoration, which would be detrimental to the restoration, it is important to limit the amount of water absorbed. The aim of this study was to evaluate and compare water sorption values of various composite materials. Seven commercial light-activated composite materials: Tetric Evo Ceram (Ivoclar, Vivadent, Schaan/Liechtenstein, Austria), Premise (Kerr, Orange, CA USA), Herculite (Kerr), Z100 (3M-ESPE, St. Paul, MN, USA), Z250 (3M-ESPE), P60 (3M-ESPE) and SupremeXT (3M-ESPE). Ten disc specimens were prepared for each composite material using a stainless steel mold with 15 mm in inner diameter and 1 mm in thickness. The curing of each composite specimen was divided into 5 segments and each segment was photo-cures for 40 seconds. Water sorption of different materials was calculated by means of weighting the samples before and after water immersion (15 days) and desiccation. Data were analyzed by one-way ANOVA at 5% level of significance. Tetric Evo Ceram composite showed the lowest water sorption values followed by Herculite, P60, supreme XT, Z100, Z250 and Premise which exhibited the highest values. All the composites being tested in this study exhibited sorption values within the acceptable limits and composite composition significantly influenced its water sorption value

Comparing the effects of propofol and isoflurane on depth of anesthesia and blood loss during endoscopic sinus surgery

Background: Endoscopic sinus surgery (ESS) is one of the procedures which need a clear surgical field. The purpose of this study was to compare the effects of propofol and isoflurane on depth of anaesthesia and blood loss during ESS. Materials and Methods: In this clinical trial study, 52 (36 males and 16 females) ESS candidates referred to the Shafa hospital in Kerman. One group received propofol and another group isoflurane. Mean arterial blood pressure (MAP), depth of anaesthesia (DA) and total blood loss were recorded for patients in both groups. Results: DA was decreased in both groups, but no significant correlation was observed between the two groups in DA, MAP and blood loss. Moreover, no significant difference was observed between the two groups in total blood loss. Blood pressure was decreased in both groups during surgery. Conclusion: There is no significant difference between propofol and isoflurane in DA and decreasing blood loss during ESS. Therefore, we suggest the use of hypotensive anaesthetic agents during ESS

Strategic purchasing in the market of advanced medical equipment: an applied model for developing countries

Background: Purchasing health services related to advanced medical equipment is merely based on the decision of the providers in Iran as a developing country in West Asia. This passive process makes health insurance organizations reimburse the bills retrospectively. This study aimed at developing a model for the strategic purchasing of high-tech medical services in Iranian health insurance organizations. Methods: This was a mixed-method study consisting of a qualitative and a quantitative phase. In the qualitative phase, a scoping study was performed to identify the indicators and strategies of strategic purchasing of high-tech medical services in the world and then the primary model of strategic purchasing of high-tech medical services was developed for Iranian health insurance organizations by an expert panel. In the quantitative phase, the developed model was validated by the Delphi technique. Results: Narrative analysis of the articles yielded six main dimensions and 36 sub-dimensions of strategic purchasing of high-tech medical services each of which was relevant to one of the five main questions of strategic purchasing. The main dimensions were the position of strategic purchasing in the health system, organization and management, position of internal and external stakeholders, health technology assessment, pricing, and indicators of contracting. Conclusion: In the present model, six applied dimensions were achieved for implementing strategic purchasing in Iranian Health Insurance Organization. The relationship of �stewardship and position of health system� and �Position of health stakeholders� which are responsible for all resource allocation and purchasing mechanism in the health system are emphasized. Simultaneously, the model emphasized �structure and management of the provider organizations� that is important for determining the real needs of the community and managing the correct medical demand. © 2020 Fellowship of Postgraduate Medicin

Designing a pragmatic model for strategic purchasing of health services in health insurance companies: The feasible pivot of strategic purchasing in a developing country

Purpose: The purpose of this paper is to identify the most important factors for strategic purchasing of health services in the health sector by the Iran Health Insurance Company and to provide an applicable model for other similar organizations in developing countries. Design/methodology/approach: The present qualitative study was conducted in 2017 to identify the factors affecting the implementation of strategic purchasing of health services in the health sector by the Iran Health Insurance Company and to provide an indigenous and practical model through two phases: semi-structured interview followed by a Delphi process. Findings: According to the findings of this study, Ministry of Welfare, Labor and Social Security plays a central role in the strategic purchasing. In addition, this was also approved by the representatives of citizens in communities concerning professional associations, insurance agencies and representative of the Council of Ministers. Model development explored 9 themes and 54 sub-themes. Research limitations/implications: Based on the model, most attention has been paid to consumer role and inter-sector leadership of the company with other relevant organizations and systems including other insurance organizations and the welfare ministry. More importantly, the health insurance company should be able to communicate with providers and to choose the best providers, receiving price information through competition in the most appropriate mechanism. Guided by this model, it can strategically buy the best and the most effective services for its insured population. Social implications: It might help developing societies to promote their health systems based on targeting the health budgeting and financial constraints so that it is prioritized according to the strategic purchasing criteria and consequently, economic evaluation. Originality/value: The linchpins of the present study are as follow: first, the pragmatic model presented in the paper could help developing health systems to overcome the impediment in the implementation progress of strategic purchasing. Second, the model satisfies the need of enough knowledge to apply strategic purchasing in the health system. Third, the indigents have long been given special protection and consideration in the model that has continued to capture the attention of every policy-maker, in particular, developing countries, the portion of which is significant. Fourth, based on this model, attention has been paid to consumer role and inter-sector leadership of organization with other relevant organizations and systems. Fifth, this model could be correspondent for every insurance company in countries with similar developing conditions. © 2018, Emerald Publishing Limited