Smart PV Inverter Control for Distribution Systems

PV solar systems employ inverters to transform dc power from solar panels into ac power for injecting into the power grids. Inverters that perform multiple functions in addition to real power production are known as “smart inverters”. This thesis presents a novel control of PV inverter as a dynamic reactive power compensator – STATCOM. This “smart PV inverter” control enables a PV solar inverter to operate in three modes – i) Full PV, ii) Partial STATCOM, and iii) Full STATCOM, depending upon system needs. The novel control is developed and demonstrated for the objectives of a) symmetrical voltage regulation, b) temporary overvoltage reduction, c) power factor correction, and d) reactive power control. In Full PV mode, the inverter performs only real power production based on solar radiation. In Partial STATCOM mode, the controller uses the remaining capacity of the inverter for voltage control, power factor correction and reactive power control. The Full STATCOM mode is invoked in emergency scenarios, such as faults, or severe voltage fluctuations. In this mode, the real power production is shut down temporarily and the entire inverter capacity is utilized for voltage regulation or TOV curtailment for providing critical support to the power system. This thesis presents a comprehensive design of the proposed smart inverter controller with all its associated system components. The performance of the smart inverter is simulated using the electromagnetic transients software PSCAD/EMTDC. It is further validated through Real Time Digital Simulation and Control Hardware in the Loop (CHIL) simulation. Finally the successful performance of the smart inverter controller is demonstrated on a 10 kW inverter in the laboratory on a simulated feeder of Bluewater Power, Sarnia, where this smart inverter is proposed to be installed. The smart PV inverter control is further shown to enhance the connectivity of PV solar farms in a realistic 44 kV Hydro One distribution feeder. It is demonstrated that if such a novel control is implemented on a 10 MW solar farm, the need for the actually installed STATCOM for voltage regulation and TOV control can be either minimized or altogether eliminated, bringing a significant savings for the utility PV solar systems employ inverters to transform dc power from solar panels into ac power for injecting into the power grids. Inverters that perform multiple functions in addition to real power production are known as “smart inverters”. This thesis presents a novel control of PV inverter as a dynamic reactive power compensator – STATCOM. This “smart PV inverter” control enables a PV solar inverter to operate in three modes – i) Full PV, ii) Partial STATCOM, and iii) Full STATCOM, depending upon system needs. The novel control is developed and demonstrated for the objectives of a) symmetrical voltage regulation, b) temporary overvoltage reduction, c) power factor correction, and d) reactive power control. In Full PV mode, the inverter performs only real power production based on solar radiation. In Partial STATCOM mode, the controller uses the remaining capacity of the inverter for voltage control, power factor correction and reactive power control. The Full STATCOM mode is invoked in emergency scenarios, such as faults, or severe voltage fluctuations. In this mode, the real power production is shut down temporarily and the entire inverter capacity is utilized for voltage regulation or TOV curtailment for providing critical support to the power system. This thesis presents a comprehensive design of the proposed smart inverter controller with all its associated system components. The performance of the smart inverter is simulated using the electromagnetic transients software PSCAD/EMTDC. It is further validated through Real Time Digital Simulation and Control Hardware in the Loop (CHIL) simulation. Finally the successful performance of the smart inverter controller is demonstrated on a 10 kW inverter in the laboratory on a simulated feeder of Bluewater Power, Sarnia, where this smart inverter is proposed to be installed. The smart PV inverter control is further shown to enhance the connectivity of PV solar farms in a realistic 44 kV Hydro One distribution feeder. It is demonstrated that if such a novel control is implemented on a 10 MW solar farm, the need for the actually installed STATCOM for voltage regulation and TOV control can be either minimized or altogether eliminated, bringing a significant savings for the utilit

Prevalence of Zoonotic Intestinal Helminths of Canids in Moghan Plain, Northwestern Iran

Background: The present study was aimed to elucidate the status of intestinal hel­minth infec­tions in canids of Moghan Plain, northwestern Iran.Methods: Eighty-five intestine samples from dead or shot wild canids, 59 fecal samples from sheepdogs and 5 from red foxes were collected from 2006 to 2008 and examined in Parasitology department of Pasteur Institute of Iran.Results: Generally, adult worms, larvae, and eggs of 13 species of various parasitic hel­minths were recovered. Necropsy examinations showed that 96.47% animals harbored at least one helminth species. The prevalence of different species in necropsy were Mesoces­toides sp. 84.7%, Rictolaria spp. 55.3%, Macranthorhynchus hirudinaceus 45.9%, Toxocara canis 43.5%, Toxas­caris spp. 35.3%, Joyeuxiella sp. 34.1%; hook­worms; 22.4%, Taenia spp. 11.8%, Alaria spp. 2.4% and Dipylidium caninum 1.2%. Be­sides, eggs belonging to 10 species of parasitic helminths were identified in 46 fecal sam­ples and generally, 30.9% of samples harbored eggs of at least one helminth species.Conclusion: The high prevalence of various helminth infections among canids in Mog­han plain and contamination of environment by helminths eggs may increase the risk of infection for native peo­ple

A Qualitative Study to Identify Skills and Competency Required for Hospital Managers

Introduction: Hospital managers aim to improve the efficiency and effectiveness of their institutions through leadership and guidance of medical personnel. Fulfilling these objectives requires a holistic approach to both the management of people and institutional prioritization. The aim of this study was to identify the skills and competencies that hospital managers must demonstrate in order to achieve their objectives. Methods: In 2015, a regional, multi-center qualitative study was undertaken in Shiraz, Iran. Interviews and focus group discussions were conducted with university hospital managers, senior managers, faculty members, and post-graduate students, and the results were analyzed using the content analysis method by MAXQDA software. Results: Eight key skill themes (communication, experience, appreciation of institution logistics/infrastructure, management skills, motivation, systematic problem solving, ethics, and financial/legal awareness) were identified among the hospital managers. The common challenges that face hospital institutions include problems with hierarchical and organizational structure, excessive rules and regulations, lack of resources, poor post-graduate education, and overall management. Recurring themes with respect to how these could be addressed included changing the culture and belief structure of the hospital, restructuring the organizational hierarchy, and empowering the people. Conclusion: In our cohort, practical skills, such as communication and experience, were considered more important than theoretical skills for the effective management and administration of hospitals. Therefore, we suggest that practical, skill-based training should be emphasized for students of these disciplines so they will be better suited to deal with real world challenges. Further organizational improvements also can be attained by the active and constructive involvement of senior university managers

Human unrestricted somatic stem cells ameliorate sepsis-related acute lung injury in mice

Background Aims: Sepsis and related disorders, especially acute lung injury (ALI), are the most challenging life-threatening diseases in the hospital intensive care unit. Complex pathophysiology, unbalanced immune condition, and high rate of mortality complicate the treatment of sepsis. Recently, cell therapy has been introduced as a promising option to recover the sepsis symptoms. The aim of this study was to investigate the therapeutic potential of human unrestricted somatic stem cells (USSCs) isolated from human umbilical cord blood in the mouse model of ALI. USSCs significantly enhanced the survival rate of mice suffering from ALI and suppressed concentrations of proinflammatory mediators TNF-α, and interleukin (IL)-6, and the level of anti-inflammatory cytokine IL-10. ALI mice injected by USSCs showed notable reduction in lung and liver injury, pulmonary edema, and hepatic enzymes, compared with the control group. These results determined the in vivo immunomodulatory effect of USSCs for recovery of immune balance and reduction of tissue injury in the mouse model of ALI. Therefore, USSCs can be a suitable therapeutic approach to manage sepsis disease through the anti-inflammatory potentia

Iranian joint registry (iranian national hip and knee arthroplasty registry)

Periodic evaluation and monitoring the health and economic outcome of joint replacement surgery is a common and popular process under the territory of joint registries in many countries. In this article we introduce the methodology used for the foundation of the National Iranian Joint Registry (IJR) with a joint collaboration of the Social Security Organization (SSO) and academic research departments considering the requirements of the Iran's Ministry of Health and Education. ©BY THE ARCHIVES OF BONE AND JOINT SURGERY

Iranian joint registry (iranian national hip and knee arthroplasty registry)

Periodic evaluation and monitoring the health and economic outcome of joint replacement surgery is a common and popular process under the territory of joint registries in many countries. In this article we introduce the methodology used for the foundation of the National Iranian Joint Registry (IJR) with a joint collaboration of the Social Security Organization (SSO) and academic research departments considering the requirements of the Iran's Ministry of Health and Education. ©BY THE ARCHIVES OF BONE AND JOINT SURGERY

The effect of oil paint vapor inhalation on FSH, LH, DHEAS, and testosterone serum levels in male rats

Background: Studies have shown that exposure to oil paints and chemicals can lead to physiological disorders. The aim of this study was to examine the effects of inhalation of oil paint vapors on the serum levels of male steroid hormones. Materials and Methods: In this experimental study, 15 adult male Wistar rats, weighing 200 to 225 g, were randomly allocated into three groups (n=5 for each group) including a control group (no treatment) and two experimental groups (which received paint vapor for 1 h and 8 hs per day). After 10 weeks, blood samples were taken from rats' hearts. Serum levels of hormones were measured using the radio immunoassay method. Data were analyzed using ANOVA and a least significant difference follow-up test. Results: Serum levels of DHEAS, LH, and FSH were increased significantly in the groups with 1 h and 8 h exposure to paint vapor compared to the control group (