Future Renewable Energy Communities Based Flexible Power Systems

This paper presents a new holistic approach that combines solutions for the future power systems. It describes clearly how solar energy is definitely the best outlet for a clean and sustainable planet, either due to their use in both vertical (V) or horizontal (H) forms such as: hydroelectric V&H, wind V&H, thermo-oceanic V&H, water movement sea V&H (tides and waves), solar thermoelectric, PV, and surface geothermal energy. New points of view and simple formulas are suggested to calculate the best characteristic intensity, storage means and frequency for specific places and how to manage the most well-known renewable sources of energy. Future renewables-based power system requires a huge amount of flexibility from different type and size of controllable energy resources. These flexible energy resources can be used in an aggregated manner to provide different ancillary services for the distribution and transmission network. In addition, flexible energy resources and renewable generation can be utilized in different kinds of energy communities and smart cities to benefit all stakeholders and society at the same time with future-proof market structures, new business models and management schemes enabling increased utilization of flexible energy resources. Many of the flexible energy resources and renewable-based generation units are also inverter-interfaced and therefore the authors present future power converter systems for energy sources as well as the latest age of multilevel converters.© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).fi=vertaisarvioitu|en=peerReviewed

Diagnosis Performance of Cerebral Venous Thrombosis with Magnetic Resonance Imaging and Magnetic Resonance Venography in Zahedan (Southeast of Iran): A Series of 57 Patients

BACKGROUND: Cerebral venous sinus thrombosis (CVST) is a scarce disease with poor prognosis and its diagnosis often challenges physicians due to nonspecific symptoms and widespread clinical manifestations. AIM: To investigate the findings of magnetic resonance imaging (MRI) and magnetic resonance venography (MRV) of patients with CVST diagnosis in Ali Ebne Abitaleb Hospital in Zahedan during 2013–2016 and to evaluate imaging pitfalls involving in late diagnosis, complications, and even death. METHODS: This retrospective descriptive study was done on 57 patients with confirmed CVST during 2013–2016 in Ali Ebne Abitaleb Hospital in Southeast of Iran (Zahedan). The MRI and MRV findings and related diagnostic pitfalls were evaluated. Twenty-one patients are pediatrics and 33 patients are adults. RESULTS: Of 57 patients, evidences of cerebral edema were found in 33 patients, among whom 2 patients showed parenchymal edema (cerebral edema) without infarction, and 31 patients exhibited parenchymal edema with infarction. The frequency of involvement in descending order was as followed; transverse sinus (96.49%), sigmoid sinus (49.12%), superior sagittal sinus (29.82%), jugular vein (19.29%), internal cerebral veins (7.01%), straight sinus (5.2%), and cortical veins (5.2%). Diagnostic pitfalls were also found in 8 patients. Seven patients exhibited acute and subacute thrombosis mimicked normal sinus flow void in T2-weighted images. No filling defect was seen on gadolinium-enhanced T1-weighted image in the other patient due to the sub-acute phase of thrombosis. CONCLUSION: The delayed diagnosis of CVST originating from nonspecific clinical features and diagnostic imaging pitfalls can result in poor outcomes in patients. To prevent the diagnostic pitfalls, the clinician should give a brief history and clinical data and radiologist(s) should interpret the findings in addition to the use of advanced MR sequences

Prophylaxis of Childhood Migraine: Topiramate Versus Propranolol

How to Cite this Article: Tonekaboni SH, Ghazavi A, Fayyazi A, Khajeh A, Taghdiri MM, Abdollah Gorji F, Azargashb E. Prophylaxis of Childhood Migraine: Topiramate Versus Propranolol. Iran J Child Neurol. 2013 Winter; 7 (1):9-14. ObjectiveHeadache is a common disabling neurological disorder and migraine comprises more than half the causes of recurrent headaches in children. Despite extended prevalence of this type of headache there is lack of evidence about best drug treatment for migraine. So we aimed to compare the therapeutic effects of these drugs on childhood migraine.Materials & MethodsIn the current study, a randomized clinical trial consisting of 78 patients according to 2004 International Headache Association criteria were randomly assigned to two groups that matched by age and sex. One of these two groups was treated with Topiramate, while the other was given Propranolol. After one and four months, the efficiency of these treatments was measured in terms of frequency, severity and duration of migraine attacks.ResultsResults obtained from the data collected showed that of these 78 studied patients, 38 patients received Topiramate treatment (group A) and the rest (40 patients; group B) was treated with Propranolol. The average age of group A was 8.5± 2.9 years and that of group B was 8.3 ± 2.8 years. No significant difference was observed between these two groups in terms of reduction in frequency, severity and duration of migraine attacks.ConclusionResults showed that both treatments had the same efficiency in healing migraine headaches and there was no significant difference between their treating results. However, further studies are needed to examine medical effects of these two medicines. ReferencesAbu-Arefeh  I,  Russell  G.  Prevalence  of  headache  and migraine in schoolchildren. BMJ 1994 Sep 24; 309 (6957): 765-9.Lipton RB, Silberstein SD, Stewart WF. An update on the epidemiology of migraine. Headache 1994 Jun; 34 (6):319-28.Stewart WF, Linet MS, Celentano DD, Van Natta M, Ziegler D. Age- and sex-specific incidence rates of migraine with and without aura. Am J Epidemiol 1991 Nov; 134 (10): 1111-20.Marcos J. Cruz, Ignacio Valencia, Agustı´n Legido, et al, Efficacy and Tolerability of Topiramate in Pediatric Migraine. Pediatr Neurol 2009; 41: 167-170.Ashrafi  MR,  Shabanian  R,  Zamani  GR,  Mahfelati  F. Sodium valproat versus Propranolol in pediatric migraine prophylaxis. Eur J Pediatr Neurol 2005; 9 (5): 333-8.Hershey AD, Winner PK. Pediatric migraine: recognition and treatment. J Am Osteopath Assoc 2005 Apr; 105:4 ( Supple 2):2S–8S.Lewis DW, Scott D, Rendin V. Treatment of pediatric headache. Expert Opin Pharmacother 2002 Oct;3(10):1433-42.Stewart WF, Lipton RB, Kolodner K, Liberman J, Sawyer J. Reliability of the migraine disability assessment scores in a population-based sample of headache sufferers. Cephalalgia 1999 Mar; 19 (2): 107-14.Hershey AD,  Powers  SW,  Vockell ALB,  LeCates  SL, Kabbouche MA, Maynard MK. PedMIDAS: development of a questionnaire to assess disability of migraines in children. Neurology 2001 Dec; 57(11): 2034-9.Hershey AD, Powers SW, Vockell ALB, LeCates SL, Segers A, Kabbouche MA. Development of a patient- based grading scale for PedMIDAS. Cephalalgia 2004 Oct; 24 (10): 844-9.Ferraro D, Di Trapani G. Topiramate in the prevention of pediatric migraine: literature review. J Headache Pain 2008 Jun; 9 (3): 147-50.J W. Lance and P J. Goadsby. Mechanism and Management of Headache. Butterworth-Heinemann; 7th edition, 2004.Lipton RB, Silberstein SD. Stewart WF. An update on the epidemiology of migraine. Headache 1994 Jun; 34(6):319-28.

Diagnostic Accuracy of Ultrasonography in Diagnosis of Metatarsal Bone Fracture; a Cross Sectional Study

Introduction: Metatarsus is one of the most common sites in the sole of foot bones fractures. The aim of this study was to determine the diagnostic accuracy of ultrasound in diagnosis of metatarsal bone fractures following foot trauma. Methods: This cross-sectional study was carried out on patients with blunt foot trauma admitted to emergency department of a hospital in Mashhad, Iran from January to September 2016. All patients were evaluated with bedside ultrasound for the presence of first to fifth metatarsal fractures and screening performance characteristics of ultrasonography in detection of metatarsal fractures were calculated considering foot radiography as the reference test. Results: The study was conducted on 102 patients with a mean age of 35.14±14.32 years (56.8% male). The most common signs of trauma in physical examination were pain and tenderness (100%), swelling (96.1%), ecchymosis (14.7%) and deformity (1.9%). Sensitivity, specificity, and positive and negative likelihood ratio of ultrasonography in detection of metatarsal bone fracture were 96.7% (95% CI: 0.83-0.99), 84.5% (95% CI: 0.73-0.92), 73.1% (95% CI: 0.57-0.85), and 98.3% (95% CI: 0.91-0.99), respectively. The overall accuracy of ultrasonography was 0.906 (95% CI: 0.844 – 0.969) based on area under the receiver operating characteristic (ROC) curve. Conclusion: Considering the excellent diagnostic accuracy, ultrasonography can be used as an alternative means in diagnosis of metatarsal bone fractures

Controllability on infinite-dimensional manifolds

Following the unified approach of A. Kriegl and P.W. Michor (1997) for a treatment of global analysis on a class of locally convex spaces known as convenient, we give a generalization of Rashevsky-Chow's theorem for control systems in regular connected manifolds modelled on convenient (infinite-dimensional) locally convex spaces which are not necessarily normable.Comment: 19 pages, 1 figur

Factors affecting medical major selection and the extent of changes in students’ motivation during their study in Ahvaz Jundishapur University of Medical Sciences

Introduction: Assessment and identification of factors and motivations affecting medical major selection could be effective in training committed physicians and improving society’s general health. The aim of this study was to assess the factors and motivations which affect medical students’ major selection. Methods: In this descriptive cross-sectional study, opinions of 351 medical students of Ahvaz Jundishapur University of Medical Sciences who were selected by means of census method in 2014-15 were analyzed. Data were collected by a 22-item questionnaire whose validity was verified by experts. Its reliability was confirmed by Cronbach’s alpha at 0.84. Descriptive statistical tests, independent t-test and ANOVA were used to analyze the data. Results: 185 students (57.5%) were female and 191 (61%) were natives of Khuzestan Province and their average age was 22.33±3.7 (18-32 years old). According to the mean scores, individual motivations and serving the society (3.07±0.69), employment, high income and social status (3.01±0.68) and interest in the medical field (2.87±0.98) were the most important factors affecting medical major selection. The role of family and friends in female students’ major selection was significantly more important than male students (p=0.03, F=1.255). Comparison of the views of students divided by their year of entrance to the university showed that the mean score of students’ views in most of the aspects decreases significantly (p=0.001, F=34.97). Conclusion: Medical students believe that serving the society, high income and social status are important factors in medical major selection. With higher educational stage, students’ motivation and interest in studying medical fields would decrease. Decreased motivation of medical students during their study should be taken as a warning for the authorities of health care sector

فراینداکسیدانیو کاتالیتیکی آهن دو ظرفیتی/ پرسولفات/ کلینوپتی لولایت به عنوان یک روش مقرون به صرفه جهت تصفیه پساب واحد ایزوسیانات و متاتولوئن دی آمین پتروشیمی

Background: Petrochemical wastewater from isocyanate units contains aromatic and hazardous compounds such as Diaminotoluenes, Mononitrotoluene, Dinitro-toluene, Nitro-phenol, Nitro-cresol. Persulfate and ferrous sulfate can produce sulfate radicals with strong standard oxidation potential. Clinoptilolite, a natural adsorbent; plus sulfate radicals can result in catalytic oxidation of these chemicals. The objective of this study is to evaluate the catalytic oxidation efficiency Fe2+/Persulfate/ Clinoptilolite and cost effectiveness of this process for treatment of petrochemical wastewater containing aromatics.Materials and methods: The effect of study variables including persulfate and ferrous sulfate concentrations, zeolite dosages, pH and oxidation time were investigated. The type and amount of aromatic compounds as well as COD and TSS removal efficiencies were determined. All procedures in study were conducted ethicallyResults: The COD and TSS removal efficiencies using catalytic oxidative treatment processes by Fe,Persulfate, Clinoptilolite were 96% and 95%, respectively. The corresponding COD and TSS removal efficiencies using Fe and Persulfate, without zeolite were 85% and 80%, respectively.Conclusion: The catalytic processes utilizing Fe2+/Persulfate/ Clinoptilolite demonstrates an excellent COD and TSS removal efficiency. Due to its natural nature, low cost compared to chemical oxidants, as well as improvements in the efficiency of advanced oxidation processes, Zeolite can be considered as an efficient and cost-effective alternative to upgrade the catalytic oxidative treatment. زمینه و اهداف: پساب واحد ایزوسیانات پتروشیمی، حاوی ترکیبات آروماتیک خطرناک و متنوع میباشد. پرسولفات و آهن دو ظرفیتی، میتوانند رادیکالهای سولفات با پتانسیل اکسیداسیون بالا تولید نمایند. کلینوپتیلولایت یک جاذب طبیعی میباشد که همراه با رادیکالهای سولفات میتوانند باعث فرایند تصفیه اکسیداتیو کاتالیکی شوند. هدف از این مطالعه ارزیابی کارایی و هزینه فرایند اکسیداتیو کاتالیتیکی آهن دو ظرفیتی، پرسولفات، کلینوپتیلولایت برای تصفیه پساب پتروشیمی حاوی ترکیبات آروماتیک میباشد. مواد و روشها: تاثیر متغیرهای مختلف شامل غلظت پرسولفات، سولفات آهن و زئولیت،pH و زمان اکسیداسیون مورد بررسی قرار گرفت و در نهایت مقدار حذف COD و TSS در نمونه های تصفیه شده مشخص گردید. در کلیه مراحل انجام پژوهش، موازین اخلاقی، مراعات گردید. یافته ها: مقدار حذف COD و TSS توسط فرایند تصفیه کاتالیتیکی اکسیداتیو با استفاده از سولفات آهن، پرسولفات و کلینوپتیلولایت به ترتیب 96 و 95 درصد بود. در حالیکه مقدار حذف COD و TSS توسط فرایند سولفات آهن، پرسولفات و بدون استفاده از کلینوپتیلولایت حدود 85 و 80 درصد بود. نتیجه گیری: در فرایند تصفیه اکسیداسیون کاتالیتیکی که در آن به طور همزمان از آهن دو ظرفیتی/ پرسولفات و کلینوپتیلولایت استفاده میگردید، بیشترین مقدار حذف COD و TSS نشان داده شد. با توجه به طبیعی بودن زئولیت و هزینه کم آن نسبت به مصرف مواد شیمیایی و همچنین بهبود قابل توجه راندمان فرایند اکسیداسیون پیشرفته، استفاده از آن از نظر فنی و اقتصادی توجیه پذیر میباشد

Optimization of ReaxFF Reactive Force Field Parameters for Cu/Si/O Systems via Neural Network Inversion with Application to Copper Oxide Interaction with Silicon

The presence of transition metal oxide impurities introduced during crystal formation or during the fabrication process may lead to a significant yield loss in microelectronics and device manufacturing. To enable a large-scale molecular dynamics study of the effects of copper oxide impurities inside silicon on the structural evolution and mechanical properties of Cu/Si/O systems, one needs to understand the diffusional characteristics of copper and oxygen compounds next to the silicon lattice. In this work, we introduce an accelerated deep learning-based reactive force field parametrization platform. In this platform, we train a deep neural network to learn the production of ReaxFF outputs, given a set of force field parameters. Subsequently, the trained neural network is used, as an alternative to ReaxFF, by means of the neural network inversion algorithm to seek the inputs to the neural network (force field parameters) that produce the experimental and quantum mechanics reference property values of the system. We compared the performance of the neural network inversion optimization algorithm with that of the previously used brute force search method by looking at the total optimization time and the total reduction of the discrepancies between the results of molecular dynamic simulation and the reference property values within the force field training set. The neural network inversion algorithm significantly reduces the average optimization time, which directly translates into less computational resources required for the optimization process. Moreover, we compared the quality of the force fields optimized by both algorithms in describing the chemical properties of the Cu/O systems, including the heat of formation and the relative phase stability. We demonstrated that the results of the force field, optimized using the proposed neural network inversion algorithm, align more closely with the reference chemical properties of Cu/O systems within the force field training set than those optimized by the brute force algorithm. We used this platform to develop a Cu/Si/O ReaxFF reactive force field by training on density functional theory (DFT) data, including heat of formation values for various Cu/Si/O materials. The developed force field was further used to perform molecular dynamics simulations on models with up to 3542 atoms to study atomistic interactions between copper oxide compounds and silicon by looking at the diffusional behavior of copper and oxygen atoms adjacent to the Si substrate. We found that the temperature substantially impacts the Cu oxide diffusion coefficient. Our simulation results enable us to comprehensively understand the effects of oxygen atoms on the diffusion of copper impurities into the silicon lattice. We showed that a Cu oxide cluster shows diffusion faster than that of a pure Cu cluster adjacent to a Si supercell. By studying the interaction between Cu oxide and Si nanolayers at different temperatures, we observed that at higher temperatures, oxygen atoms migrate from the initial CuOx material to diffuse into the Si phase. In addition, we showed that the absolute decay rate of the average Cu–Cu bond length is directly dependent on the simulation temperature