Protection and Control of Active Distribution Networks and Microgrids

This thesis is mainly focused on (i) modeling and control of Electronically Coupled Distributed Energy Resources (EC-DERs) under severe network imbalances and transient incidents, and (ii) protection of active distribution networks and microgrids against different types of faults. In the first part, an enhanced control strategy is proposed to improve the performance of EC-DERs under faults and transient disturbances, in a multi-unit microgrid setting. With the use of proposed control strategy, the host microgrid can ride through network faults, irrespective of whether they take place within the microgrid jurisdiction or impact the upstream grid, and quickly reclaim its pre-fault operating conditions to improve post-fault recovery. Further, the proposed control scheme enables the host microgrid to retain its power quality for the duration of the faults, in both modes of operation, which is a desirable property for detection of certain classes of faults, as well as for sensitive loads. In the second part of the thesis, appropriate strategies are proposed for protection of low- and medium-voltage microgrids in the islanded mode as well as the grid-connected mode of operation. The proposed protection strategies aim to detect and isolate the faults that impact the microgrid, in a selective manner. The proposed strategies can be implemented through programmable microprocessor-based relays which are commercially available; hence, the structure of new relays that enable the proposed protection strategies are also discussed in the thesis. In addition, the thesis investigates the operation of an existing distribution network as a microgrid. Thus, practical control and protection strategies that enable off-grid operation of the distribution network (considering the system constraints) are discussed. The effectiveness of the proposed control and protection strategies are demonstrated through time-domain simulation studies conducted in the PSCAD/EMTDC software environment

Evaluation of demographic features of acute drug poisoning with Benzodiazepines; a cross – sectional study

Background: Poisoning is one of the important social problems in developing countries, and acute poisoning due to suicide by drug overdose or toxins is one of the most common cases of poisoning that requires emergency care. This study was aimed to determine the demographics of benzodiazepines poisoned patients in one of the referral centers for poisoning in Iran.Materials and Methods: This cross-sectional study was conducted on patients who referred to the poisoning emergency ward of Loghman Hakim Hospital from April 2015 to March 2016. Among 10624 patients who referred to the hospital at the study period, 2543 of them were poisoned by benzodiazepines. A total of 263 patients were selected randomly and were assessed for age, gender and the type of the benzodiazepine. The data were analyzed by version 15 of SPSS software.Results: Among 263 patients, 127 were males (48.2%) and 136 were females (51.7%). The mean age of patients was 31 years old with a range of 13 – 80 years old. In addition, most patients were in the age of between 18 to 35 years (n = 152). In this study, 91 patients (34.6%) were single-drug poisoned with benzodiazepines and 172 cases (65.4%) were poisoned by multi-drug regimens including benzodiazepines. Between different types of benzodiazepines, the most common type was Alprazolam and the least common benzodiazepine was Oxazepam. Almost 96% of patients (n = 252) were treated successfully and 8 patients (3%) got discharged with self-consent. Furthermore, the mortality rate was approximately 1% (n = 3).Conclusion: Benzodiazepines poisoning is common in younger patients; thus, close attentions are needed for the prescription of these drugs in young patients. Considering easy access to benzodiazepines in the community, periodic visits to psychiatrists may be useful for the reduction of benzodiazepine poisoning

Survey of spiders (Arachnida: Araneae) in southwestern Iran, with new records

Twenty-nine locations in Kohgiluyeh & Boyer-Ahmad Province in southwestern Iran were sampled for spiders (Araneae) in 2016–17 using different sampling methods (hand collection, pitfall traps, and aspirators). A total of 196 identifiable specimens were collected which represented 49 species belonging to 38 genera and 15 families. Six species, namely Cheiracanthium elegans Thorell, 1875 (Cheiracanthiidae), Cryptodrassus helvolus (O. Pickard-Cambridge, 1872) (Gnaphosidae), Enoplognatha macrochelis Levy & Amitai, 1981 (Theridiidae), Xysticus xerodermus Strand, 1913 (Thomisidae), Zelotes babunaensis (Drensky, 1929) and Z. potanini Schenkel, 1963 (both Gnaphosidae) had not been previously reported from Iran. Also, an additional number of 35 species represent new records for the province.</p

Relationship between β-Thalassemia minor and Helicobacter pylori infection

Background: Until now, no study has been reported investigating the association between β-thalassemia minor and Helicobacter pylori (H. pylori) infection. This study was designed to compare H. pylori infection rate between β-thalassemia minor patients and healthy controls. Methods: A number of 100 β-thalassemia minor patients (50 males, 50 females) and 100 gender-matched healthy controls were prospectively recruited in this study in a period of 3 months. The study population consisted of the people who referred to a health center in Babol, North of Iran, for premarital counseling. H. pylori status was assessed by measuring the anti-H. pylori IgG antibodies using enzyme-linked immunosorbent assay. Demographic information and informed consent were collected from all participants. Results: The overall H. pylori infection rate was 43%. The infection was significantly more prevalent in thalassemia patients (53%) than in the controls (33%) in both univariate (OR=2.29, 95% CI: 1.3-4.06) and multivariable analyses (OR=2.05, 95% CI: 1.12-3.76). Age was the only significant factor which was positively correlated with the infection in β-thalassemia minor cases (OR=1.11, 95% CI: 1.02-1.2). Gender, blood groups, residency, and education level were not related to the infection. Conclusions: According to the results, it can be concluded that β-thalassemia minor patients are possibly more susceptible to H. pylori infection than healthy people. Further studies are needed to discover more about the exact mechanisms of increased susceptibility to H. pylori infection in β-thalassemia minor patients

The Relationship between Clinical Findings of Shoulder Joint with Bone Damage of Shoulder Joint in Patients with Isolated Shoulder Blunt Trauma

BACKGROUND: Due to the prevalence of shoulder injuries among athletes and other people and the prevalence of radiography for these injuries, there are still no valid criteria for indication of doing shoulder radiography. AIM: This study aimed to examine the relationship between some signs and clinical examinations of the shoulder with shoulder bone injuries and the need for radiography. METHODS: This is a cross-sectional study. All patients aged 18-70 years who referred to the emergency ward of Imam Reza and Hasheminejad Hospital in the year 2014 due to blunt trauma and had criteria for entering the study and lacking exclusion criteria were included in the study process. Data on clinical symptoms, radiographic results, and final diagnosis were extracted from the patients' records through a questionnaire and analysed statistically. RESULTS: There was a significant relationship between the clinical signs of patients Existence of ecchymosis in the shoulder fractures with glenoid and humerus fractures (p = 0.029, p = 0.004 respectively). There was also a significant relationship between clavicle fracture and limitation in shoulder rotation and abduction (p = 0.000 and p = 0.001 respectively). Other clinical symptoms did not show any significant relationship with radiographs indicative of the problem requiring specific treatment. CONCLUSION: Although it is possible to define critters based on clinical symptoms that reduce the need for unnecessary radiographs that the does not reliably help inpatient treatment, but finding these critters to indicate the performance of the graphs in shoulder injuries requires further studies with the higher population and more clinical variables

Preparation and characterization of calcium hydroxyphosphate (hydroxyapatite) from tilapia fish bones and scales via calcination method

Calcium hydroxyphosphate (hydroxyapatite) is a calcium phosphate that is widely used in biomedical application. Hydroxyapatite is an excellent component for bone substitutes for their chemical and structural similarity to natural bone component. In this research, hydroxyapatite was synthesized from tilapia fish bones and scales using calcination method with 3 different temperatures namely 1000 °C, 900 °C and 800 °C. The obtained hydroxyapatite powder was characterized using several techniques such as Fourier-Transform infrared spectroscopy Attenuated total reflection (FTIR-ATR), scanning electron microscope (SEM), proximate analysis and X-ray diffraction (XRD). The results indicated that temperature 1000 °C has the highest weight loss with 21.825 g compared to the temperature 800 °C and 900 °C. From FTIR-ATR analysis, the presence of characteristic peaks for hydroxyl group, phosphate groups and water molecule indicated that the powder were hydroxyapatite. SEM results showed that increasing temperature had led to more dense structure. The hydroxyapatite powder were further analysed for their proximate analysis. The results proved that the highest contents of ash, fat, moisture and crude protein were observed at 1000 °C as compared to 900 °C and 800 °C. Based on this study, it revealed that produced pure hydroxyapatite from natural resources could be a potential candidate for food industry as protein enhancer

Epidemiology of injuries from fire, heat and hot substances : global, regional and national morbidity and mortality estimates from the Global Burden of Disease 2017 study

Background Past research has shown how fires, heat and hot substances are important causes of health loss globally. Detailed estimates of the morbidity and mortality from these injuries could help drive preventative measures and improved access to care. Methods We used the Global Burden of Disease 2017 framework to produce three main results. First, we produced results on incidence, prevalence, years lived with disability, deaths, years of life lost and disability-adjusted life years from 1990 to 2017 for 195 countries and territories. Second, we analysed these results to measure mortality-to-incidence ratios by location. Third, we reported the measures above in terms of the cause of fire, heat and hot substances and the types of bodily injuries that result. Results Globally, there were 8 991 468 (7 481 218 to 10 740 897) new fire, heat and hot substance injuries in 2017 with 120 632 (101 630 to 129 383) deaths. At the global level, the age-standardised mortality caused by fire, heat and hot substances significantly declined from 1990 to 2017, but regionally there was variability in age-standardised incidence with some regions experiencing an increase (eg, Southern Latin America) and others experiencing a significant decrease (eg, High-income North America). Conclusions The incidence and mortality of injuries that result from fire, heat and hot substances affect every region of the world but are most concentrated in middle and lower income areas. More resources should be invested in measuring these injuries as well as in improving infrastructure, advancing safety measures and ensuring access to care.Peer reviewe

Mapping local patterns of childhood overweight and wasting in low- and middle-income countries between 2000 and 2017

A double burden of malnutrition occurs when individuals, household members or communities experience both undernutrition and overweight. Here, we show geospatial estimates of overweight and wasting prevalence among children under 5 years of age in 105 low- and middle-income countries (LMICs) from 2000 to 2017 and aggregate these to policy-relevant administrative units. Wasting decreased overall across LMICs between 2000 and 2017, from 8.4% (62.3 (55.1–70.8) million) to 6.4% (58.3 (47.6–70.7) million), but is predicted to remain above the World Health Organization’s Global Nutrition Target of <5% in over half of LMICs by 2025. Prevalence of overweight increased from 5.2% (30 (22.8–38.5) million) in 2000 to 6.0% (55.5 (44.8–67.9) million) children aged under 5 years in 2017. Areas most affected by double burden of malnutrition were located in Indonesia, Thailand, southeastern China, Botswana, Cameroon and central Nigeria. Our estimates provide a new perspective to researchers, policy makers and public health agencies in their efforts to address this global childhood syndemic

Hearing loss prevalence and years lived with disability, 1990–2019: findings from the Global Burden of Disease Study 2019

Background Hearing loss affects access to spoken language, which can affect cognition and development, and can negatively affect social wellbeing. We present updated estimates from the Global Burden of Disease (GBD) study on the prevalence of hearing loss in 2019, as well as the condition's associated disability. Methods We did systematic reviews of population-representative surveys on hearing loss prevalence from 1990 to 2019. We fitted nested meta-regression models for severity-specific prevalence, accounting for hearing aid coverage, cause, and the presence of tinnitus. We also forecasted the prevalence of hearing loss until 2050. Findings An estimated 1·57 billion (95% uncertainty interval 1·51–1·64) people globally had hearing loss in 2019, accounting for one in five people (20·3% [19·5–21·1]). Of these, 403·3 million (357·3–449·5) people had hearing loss that was moderate or higher in severity after adjusting for hearing aid use, and 430·4 million (381·7–479·6) without adjustment. The largest number of people with moderate-to-complete hearing loss resided in the Western Pacific region (127·1 million people [112·3–142·6]). Of all people with a hearing impairment, 62·1% (60·2–63·9) were older than 50 years. The Healthcare Access and Quality (HAQ) Index explained 65·8% of the variation in national age-standardised rates of years lived with disability, because countries with a low HAQ Index had higher rates of years lived with disability. By 2050, a projected 2·45 billion (2·35–2·56) people will have hearing loss, a 56·1% (47·3–65·2) increase from 2019, despite stable age-standardised prevalence. Interpretation As populations age, the number of people with hearing loss will increase. Interventions such as childhood screening, hearing aids, effective management of otitis media and meningitis, and cochlear implants have the potential to ameliorate this burden. Because the burden of moderate-to-complete hearing loss is concentrated in countries with low health-care quality and access, stronger health-care provision mechanisms are needed to reduce the burden of unaddressed hearing loss in these settings

Adolescent transport and unintentional injuries: a systematic analysis using the Global Burden of Disease Study 2019

Background: Globally, transport and unintentional injuries persist as leading preventable causes of mortality and morbidity for adolescents. We sought to report comprehensive trends in injury-related mortality and morbidity for adolescents aged 10–24 years during the past three decades. Methods: Using the Global Burden of Disease, Injuries, and Risk Factors 2019 Study, we analysed mortality and disability-adjusted life-years (DALYs) attributed to transport and unintentional injuries for adolescents in 204 countries. Burden is reported in absolute numbers and age-standardised rates per 100 000 population by sex, age group (10–14, 15–19, and 20–24 years), and sociodemographic index (SDI) with 95% uncertainty intervals (UIs). We report percentage changes in deaths and DALYs between 1990 and 2019. Findings: In 2019, 369 061 deaths (of which 214 337 [58%] were transport related) and 31·1 million DALYs (of which 16·2 million [52%] were transport related) among adolescents aged 10–24 years were caused by transport and unintentional injuries combined. If compared with other causes, transport and unintentional injuries combined accounted for 25% of deaths and 14% of DALYs in 2019, and showed little improvement from 1990 when such injuries accounted for 26% of adolescent deaths and 17% of adolescent DALYs. Throughout adolescence, transport and unintentional injury fatality rates increased by age group. The unintentional injury burden was higher among males than females for all injury types, except for injuries related to fire, heat, and hot substances, or to adverse effects of medical treatment. From 1990 to 2019, global mortality rates declined by 34·4% (from 17·5 to 11·5 per 100 000) for transport injuries, and by 47·7% (from 15·9 to 8·3 per 100 000) for unintentional injuries. However, in low-SDI nations the absolute number of deaths increased (by 80·5% to 42 774 for transport injuries and by 39·4% to 31 961 for unintentional injuries). In the high-SDI quintile in 2010–19, the rate per 100 000 of transport injury DALYs was reduced by 16·7%, from 838 in 2010 to 699 in 2019. This was a substantially slower pace of reduction compared with the 48·5% reduction between 1990 and 2010, from 1626 per 100 000 in 1990 to 838 per 100 000 in 2010. Between 2010 and 2019, the rate of unintentional injury DALYs per 100 000 also remained largely unchanged in high-SDI countries (555 in 2010 vs 554 in 2019; 0·2% reduction). The number and rate of adolescent deaths and DALYs owing to environmental heat and cold exposure increased for the high-SDI quintile during 2010–19. Interpretation: As other causes of mortality are addressed, inadequate progress in reducing transport and unintentional injury mortality as a proportion of adolescent deaths becomes apparent. The relative shift in the burden of injury from high-SDI countries to low and low–middle-SDI countries necessitates focused action, including global donor, government, and industry investment in injury prevention. The persisting burden of DALYs related to transport and unintentional injuries indicates a need to prioritise innovative measures for the primary prevention of adolescent injury. Funding: Bill &amp; Melinda Gates Foundation