Simultaneous optimal placement and sizing of DSTATCOM and parallel capacitors in distribution networks using multi-objective PSO

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. The increase in electricity demands has increased the dimension and loading of today radial distribution feeders, which in turn would result in more losses and voltage drops. Such issues together with the demand for higher power quality has raised a need for modern power system management techniques such as using power electronic devices. Among, DSTATCOM is introduced as an effective solution for reactive power control in power distribution level. To make a better use of DSTATCOM in improving the network power quality, it should be sized and placed in accordance with parallel capacitors. A multi-objective optimization method is proposed in this paper to find the optimal location and size of DSTATCOM and parallel capacitors simultaneously. The cost of power losses, voltage profile and voltage stability are selected as objectives to be improved. The obtained results on the IEEE 33-node test system indicate that the proposed method satisfies the defined objectives and considerably improves the network operational characteristics

Multi-Objective Optimal Placement of Recloser and Sectionalizer in Electricity Distribution Feeders

© 2019 IEEE. Electricity distribution feeders, due to their geographical dispersion, are subjected to faults caused by adverse weather, vegetation growth, etc., resulting in long outages for customers. Overhead switching devices (i.e. reclosers, sectionalizers, disconnectors and etc.) are known as the most practical solutions to limit the outage area, and consequently increase the distribution system reliability. This paper presents a Multi-Objective Particle Swarm Optimization (MOPSO) algorithm for Optimal Placement of Recloser and Sectionalizer to minimize customers' outage cost and increase system reliability with an optimal investment. The algorithm determines the number and optimal locations of reclosers and sectionalizers to fulfill the objectives. The obtained results on the standard 85-node distribution feeder validate the effectiveness of the proposed method

Prevalence of nasal carriage of methicillin-resistant Staphylococcus aureus and its antibiotic susceptibility pattern in healthcare workers at Namazi Hospital, Shiraz, Iran

SummaryObjectiveThe aim of this study was to determine the prevalence of nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) among healthcare workers (HCWs) at Namazi Hospital, Shiraz, Iran.MethodsThis cross-sectional study was conducted from July to November 2006. Nasal swabs were taken from 600 randomly selected HCWs. The isolates were identified as S. aureus based on morphology, Gram stain, catalase test, coagulase test, and mannitol salt agar fermentation. To analyze sensitivity patterns of MRSA strains more precisely, minimum inhibitory concentrations (MICs) of antibiotics were determined by the E-test method. All methicillin-resistant isolates were examined for the existence of the mecA gene by total DNA extraction and PCR.ResultsThe prevalence of nasal carriage of methicillin-sensitive S. aureus (MSSA) was 25.7% and of MRSA was 5.3%, with the highest nasal carriage of MRSA in surgical wards and the emergency department. There was no significant difference between the sexes (p=0.247), age (p=0.817), and years of healthcare service (p=0.15) with regard to the nasal carriage of MRSA and MSSA. In the univariate analysis, a statistically significant difference was only found for occupation (p=0.032) between the carriage of MSSA and MRSA. In the multivariate analysis, the occupation ‘nurse’ was independently associated with MRSA carriage (p=0.012, odds ratio 3.6, 95% confidence interval 1.3–9.7). The highest resistance rate for both gentamicin and clindamycin (69%) was noted among the MRSA strains. None of the MRSA strains were resistant to mupirocin, linezolid, fusidic acid, or vancomycin. The existence of the mecA gene in all 32 methicillin-resistant isolates was observed by PCR.ConclusionsThis study revealed the prevalence of nasal carriage of S. aureus strains among HCWs to be lower than that found in other studies from Iran. The antibiotic susceptibility patterns also differed, perhaps as a result of the excessive use of antibiotics at our hospital. Only the occupation of nurse was an independent risk factor for MRSA carriage

Experimental investigation of shock-buffet criteria on a pitching airfoil

An experimental investigation of the shock-buffet phenomenon subject to unsteady pitching supercritical airfoil around its quarter chord has been conducted in a transonic wind tunnel. The model was equipped with pressure taps connected to the fast response pressure-transducers. Measurements were conducted at different free-stream Mach number from 0.61 to 0.76. The principle goal of this investigation was to experimentally discuss the shock-buffet criterion over a SC(2)-0410 supercritical pitching related to the hysteresis loops of total drag and trailing edge pressure, the behaviour of the shock wave foot location, the pressure distribution over the upper surface, and by implementing the wavelet analysis of the normal force. To ensure capturing the buffet phenomenon by utilizing these criteria, a pressure port has been drilled exactly at the trailing edge of the airfoil where its output was used to detect the buffet phenomenon for different conditions. Visual representation of the flow using the shadow graph flow visualization technique for different test cases is further used to illustrate the unsteady shock wave motion. A comparative analysis of experimental measurements shows that the conducted criteria confirm each other when the buffet phenomenon occurs at the position of the oscillating cycle

Thermal modelling of gas generation and retention in the Jurassic organic-rich intervals in the Darquain field, Abadan Plain, SW Iran

The petroleum system with Jurassic source rocks is an important part of the hydrocarbons discovered in the Middle East. Limited studies have been done on the Jurassic intervals in the 26,500 km2 Abadan Plain in south-west Iran, mainly due to the deep burial and a limited number of wells that reach the basal Jurassic successions. The goal of this study was to evaluate the Jurassic organic-rich intervals and shale gas play in the Darquain field using organic geochemistry, organic petrography, biomarker analysis, and basin modelling methods. This study showed that organic-rich zones present in the Jurassic intervals of Darquain field could be sources of conventional and unconventional gas reserves. The organic matter content of samples from the organic-rich zones corresponds to medium-to-high-sulphur kerogen Type II-S marine origin. The biomarker characteristics of organic-rich zones indicate carbonate source rocks that contain marine organic matter. The biomarker results also suggest a marine environment with reducing conditions for the source rocks. The constructed thermal model for four pseudo-wells indicates that, in the kitchen area of the Jurassic gas reserve, methane has been generated in the Sargelu and Neyriz source rocks from Early Cretaceous to recent times and the transformation ratio of organic matter is more than 97%. These organic-rich zones with high initial total organic carbon (TOC) are in the gas maturity stage [1.5–2.2% vitrinite reflectance in oil (Ro)] and could be good unconventional gas reserves and gas source rocks. The model also indicates that there is a huge quantity of retained gas within the Jurassic organic-rich intervals

Streamlining Digital Modeling and Building Information Modelling (BIM) Uses for the Oil and Gas Projects

The oil and gas industry is a technology-driven industry. Over the last two decades, it has heavily made use of digital modeling and associated technologies (DMAT) to enhance its commercial capability. Meanwhile, the Building Information Modelling (BIM) has grown at an exponential rate in the built environment sector. It is not only a digital representation of physical and functional characteristics of a facility, but it has also made an impact on the management processes of building project lifecycle. It is apparent that there are many similarities between BIM and DMAT usability in the aspect of physical modeling and functionality. The aim of this study is to streamline the usage of both DMAT and BIM whilst discovering valuable practices for performance improvement in the oil and gas projects. To achieve this, 28 BIM guidelines, 83 DMAT academic publications and 101 DMAT vendor case studies were selected for review. The findings uncover (a) 38 BIM uses; (b) 32 DMAT uses and; (c) 36 both DMAT and BIM uses. The synergy between DMAT and BIM uses would render insightful references into managing efficient oil and gas’s projects. It also helps project stakeholders to recognise future investment or potential development areas of BIM and DMAT uses in their projects

Risk Factors of Nasal Carriage of Methicillin-Resistant Staphylococcus Aureus and its Antibiotic Susceptibility Pattern in Namazi Hospital Healthcare Workers in Shiraz, Iran

Abstract: Background & Aims: Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen worldwide. The aim of this study was to determine the risk factors of nasal carriage of MRSA and its antibiotic susceptibility pattern among healthcare workers at Namazi Hospital (Shiraz-Iran) Methods: In a cross-sectional study from July to November 2006, nasal swabs were taken from 600 stratified randomly selected health care workers. The isolates were identified as S. aureus based on morphology, gram stains, catalase test, coauglase test and DNase Agar. To differentiate Methicillinsusceptible S. aureus (MSSA) and Methicillin Resistant S. aureus (MRSA), agar screen plate was used. All methicillin-resistant isolates were examined for mecA genes existence by PCR performance. The sensitivity patterns of S.aureus isolates were determined by disc diffusion and E-test method. Results: Nasal screening identified 186 (31%) S. aureus carriers of whom, 154 ones (82.8%) were MSSA and 32 ones (17.2%) were MRSA._There was no significant association between related risk factors and gender, age, years of healthcare service and level of education. In the univariate analysis, a statistically significant difference was found only based on occupation (P=0.032) between carriers of MSSA and MRSA. In multivariate analysis(logistic regression), having nursing occupation (p=0.012, OR=3.6, 95%CI=1.3-9.7) was independently associated with MRSA carriage. All of the MRSA strains were sensitive to mupirocin. Conclusion: This study revealed that having nursing occupation is independently associated with MRSA carriage since all S.aureus isolates were susceptible to mupirocin, topical mupirocin could be used successfully to eradicate nasal staphylococcal colonization and carriers. Keywords: Staphylococcus aureus, Methicillin, Risk factors, Carrier, Microbial sensitivity, Health care provider

Screening for Congenital Hypothyroidism in East Azerbaijan province, IRAN

Abstract: Background & Aims: Congenital hypothyroidism (CH) is one of the most common preventable causes of mental retardation throughout the world. The aim of this study was to investigate the prevalence of CH among newborns of East Azerbaijan province in 2009-2010. Methods: This descriptive analytic study was performed by using census cross- sectional method on 62459 neonates in East Azerbaijan province from 21st March 2009 to 20th March 2010. Blood samples were taken within the 3rd -5th days of life by lancet sticking of neonatal heel and transferred to filter papers for measuring TSH level. In the case of TSH ≥ 5mu/l, additional confirmation tests were done and confirmed cases based on serum confirmation test (TSH>10 mu/l or T4<6.5mg/dl) underwent treatment according to the national guidelines. Data were analyzed by SPSS software. Results: The recall rate was 2.5%. Total number of patients was 94, including 55 males (58.5%) and 39 females (41.5%). Prevalence in males, females and overall was respectively 1:588, 1:769 and 1:666, with no significant difference. Seasonal prevalence was respectively 1:833, 1:943, 1:492 and 1:588 that shows no significant difference among four seasons. The highest prevalence was in Tabriz (27.7%) and the lowest in Azarshahr (0%) and Kaleibar (0%). Mean maternal age of affected neonates was 26.22 ± 6.2 years. Mean neonate's weight was 3500 ± 652 grams. In 76% of neonates time of sampling was in the 3rd -5th days of life and in 89% of them test result was announced before 13th day. Mean treatment onset based on neonate's age was 2.7±1 day. In 97.5% of screened neonates TSH level was less than 5 mu/l. Conclusion: The prevalence of CH in East Azerbaijan province is significantly higher than national and worldwide levels that requires continuation and reinforcement of neonatal screening programs. On the other hand, comprehensive and complementary studies for recognizing relevant factors are among priorities of health system research in this province. Keywords: Congenital hypothyroidism, prevalence, Mass screening, Newborn, East Azarbaijan » XM

Pattern of Age Distribution of Different Cancers in East Azerbaijan province, IRAN

Abstract: Background & Aims: Cancer is a major public health problem in many countries of the world and the third leading cause of death in developing countries. The most frequently diagnosed cancers in females and males are breast and lung cancers respectively. The aim of this study was to investigate the pattern of age distribution and the frequency of different cancers in East Azerbaijan province during the year 2009. Methods: This descriptive analytic study was performed by community based method on 5455 new cancer cases obtained from cancer registries in East Azerbaijan province in 2009. Characteristics of all registered cancers (including age, sex, and etc) were collected in a form. Then data were summarized and coded using the International Classification of Disease (ICD). Data were analyzed by SPSS software. The 95% confidence interval of the study Variables were calculated using Excel software. Results: Among 5455 cases, 3189 ones (58.5%) were males and 2256 ones (41.4%) were females. Mean age of cancer incidence was 57.3 ± 18.5 years. About 47.8% of malignancies occurred in ages over 60 years and 52.2% below 60 years. Among men, 57.8% of all cancers occurred in the age group of 60-70 years but in women 53.5% of them occurred in the age group of 50-60 years. Mean age at diagnosis was significantly higher (P<0.001) among males (60 years, 95%CI: 59.7-60.9) than females (53 years, 95% CI: 52.2-53.8). The 10 most common cancers among males and females were stomach (15.5%) and breast (20.9%) cancers respectively. Conclusion: More than half of all registerd cancers in the province were in the age group of above 60 years. Stomach and breast cancers are the most common malignancies of this region and occur most frequently during the 7th and 5th decades of life respectively. Comprehensive and complementary studies for recognizing relevant factors are among the priorities of health system research in this province. Keywords: Neoplasms, Epidemiology, Age distribution, East Azerbija

Responsiveness of the Persian health assessment questionnaire measures in differentiating among disease activity levels in rheumatoid arthritis patients

Objectives: Evidence suggests that inflammation has a harmful effect on muscle strength as well as on functional disability. The purpose of the present study was to examine the association of objectively measured disease activity levels and functional disability among Iranian patients with Rheumatoid Arthritis (RA), and to analyse whether a Persian version of the health assessment questionnaire-disability index (PHAQ-DI) can distinguish between RA patients at different stages of the disease progression. Materials & methods: 198 RA patients were requested to complete the PHAQ-DI. The disease activity score for each patient was evaluated using the disease activity score (DAS-28). The association analysis between the PHAQ-DI scores and the four levels of disease activity was measured using a Spearman correlation coefficient. A Kruskal-Wallis analysis was utilized to determine differences in PHAQ-DI scores among the levels of disease activity. The Receiver operating characteristic (ROC) curve was also utilized to determine the PHAQ-DI total score cut-off for predicting the level of disease activity. Results: Spearman's correlation coefficients between the PHAQ-DI and the disease activity level ranged between 0.59 and 0.75. There were significant differences in the PHAQ-DI total score among known groups with various disease activity levels (P = 0.001); However, HAQ-DI total score could not differentiate the remission phase from low disease activity levels in patients with RA (p = 0.37). The PHAQ-DI total score cut-off for distinguishing remission-low disease activity from moderate-high disease activity was 1.19, with a specificity of 0.91 and a sensitivity of 0.615. Conclusion: The present findings provide evidence for the degree to which the PHAQ-DI measures identify and distinguish disease activity levels in patients with rheumatoid arthritis. The PHAQ-DI questionnaire, as a patient-administered, non-invasive, fast, inexpensive and available tool, can be used in the rheumatologist's office as a substitute for determining disease activity in patients with active RA. © 2020 Elsevier Lt