A High Gain AC-DC Rectifier Based on Current-Fed Cockcroft-Walton Voltage Multiplier for Motor Drive Applications

This paper proposes a novel high-gain AC-DC converter based on the Cockcroft-Walton (CW) voltage multiplier which can be utilized in motor drive systems with low input voltage. In this topology, use of the voltage multiplier and boost circuit results in the increment of converter gain which has a significant impact on the cost and efficiency of the system. Moreover, in this converter, the AC voltage is directly changed to DC voltage using the switching method in high frequency and, as well, the power factor is corrected. Besides, this high-frequency converter contributes to the reduction of output ripple. On the other hand, cost efficiency, the low voltage stress on capacitors and diodes, compactness, and the high voltage ratio, are achieved from the Cockcroft-Walton circuit. Furthermore, the hysteresis method is presented for converter switching to correct the power factor. The converter is simulated in MATLAB software to demonstrate the effectiveness of the suggested method. Lastly, a laboratory prototype of the suggested converter is built, several tests are done in order to verify the theoretical analysis, and comprehensive comparison with the state-of-the-art converter is done.© 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

Permata yang hilang: pembelajaran penulisan seni khat dan jawi / Ainun Jariah Yaacob...[et.al]

Tulisan khat/Jawi pernah menjadi skrip ilmu, komunikasi dan bahasa perantaraan (lingua franca) yang penting di kalangan masyarakat alam nusantara terutama di Tanah Melayu. Tetapi ia makin pupus dan kini sudah tidak mempunyai nilai komersial dek kerana kerakusan manusia mengejar linguistik kemodenan di tambah pula dengan lulusnya Akta Bahasa Kebangsaan 1964 yang mana merupakan penamat kepada tulisan Khat/Jawi. Bagi memakmurkan semula Seni Khat/Jawi, satu kajian berbentuk tugasan pelajar telah dirangka bagi membantu para pelajar mengenal huruf, melakarkan ciptaan, mengaplikasikan pendekatan inovatif dan rekabentuk baru dalam produk Seni Khat supaya produk kreatif khat dapat dikomersilkan untuk faedah global. Berbantukan satu sistem instruksi yang diberi nama Dars Sari‟ yang dibangunkan oleh sekumpulan tenaga pengajar khat, proses pengajaran dan pembelajaran khat menjadi mudah diingati, pantas dan efektif. Sistem yang dibina ini adalah mengikut kriteria slilibus khat serta diolah berdasarkan klasifikasi kumpulan dominan huruf bagi memudahkan proses pengajaran dan pembelajaran. Sistem instruksi ini merupakan salah satu kaedah pembelajaran yang dapat membantu para guru Seni Khat terutamanya guru Khat, J-Qof dan guru KAFA dalam mengajar subjek Seni Khat dengan efektif. Sistem ini diharap dapat memberikan impak dan tarikan baru dalam proses pengajaran dan pembelajaran Seni Khat

Spatial Analysis of Subjective Indicators of Resilience in Informal Settlements in District 4 of Zahedan City

AbstractThe aim of the current research is to analyze the spatial status of the subjective indicators of resilience in the informal settlements of Zahedan. The statistical population includes residents of three neighborhoods: Karimabad, Qasimabad, and Shirabad. The reason for choosing these neighborhoods is their high vulnerability to natural and human hazards. In order to realize the spatial dimension of the research, spatial sampling was used in such a way that the studied neighborhoods were divided into small zones using the sampling tool set and the create fishnet tool in GIS software, and a number of questionnaires were assigned to each zone depending on its population. The sample size was estimated to be 384 people, which was distributed according to the population of each neighborhood and each zone. Factor analysis tests and techniques, Pearson's correlation, one-way analysis of variance (ANOVA), and Sheffe's post hoc test were used to analyze the questionnaire data, and GIS was used to prepare the maps. The research results indicate that there is a significant difference in the researched neighborhoods in terms of resilience indicators. In addition, the spatial sense of belonging index has the greatest effect on the resilience of the studied area. The results of Pearson’s correlation show that in the two neighborhoods of Karimabad and Shirabad, the highest correlation was between the two variables of safety and health and the sense of belonging to the place. In the neighborhood of Qasimabad, the highest correlation was between the two variables of knowledge and individual skill and the improvement of the economic situation.Keywords: Urban Resilience, Spatial Sampling, Informal Settlement, Zahedan.IntroductionThe issue of informal settlements is a form of settlement in which the optimal living function is at a low level compared to other urban areas. Due to the fragility and high vulnerability of these settlements against natural threats and social harms, their resilience (as one of the four goals of regeneration) should be given serious attention. Most of these settlements are located in high-risk areas such as rivers and mountain slopes where there is a possibility of landslides. This study investigates the spatial status of the subjective indicators of resilience in the informal settlements of District 4 of Zahedan City. Materials and MethodsThe present research is applied in terms of its purpose. In terms of nature and method, it is among descriptive-analytical studies. In order to realize the spatial dimension of the research, spatial sampling was used in such a way that the studied neighborhoods were divided into small zones using the sampling tool set and the fishnet tool in GIS software, and a number of questionnaires belonged to each zone depending on its population. The statistical population of the present study, which is considered among the informal settlements of Zahedan City, includes the residents of three neighborhoods: Karimabad, Qasimabad, and Shirabad. The reason for choosing these neighborhoods is their high vulnerability to all kinds of natural and human hazards (the passage of the fundamental fault near Mahdowa and the passage of the main roads of the city through the middle). It is one of the natural and human hazards that threaten the area and its residents. The sample size was estimated to be 384 people, which was distributed according to the population of each neighborhood and each zone. The validity of the questionnaire was evaluated using the opinions of supervisors, consultants, and other experts in the urban area, and their corrective opinions were applied and finally confirmed. The reliability of the questionnaire results was also measured using Cronbach's alpha, the value of which was 0.814, which indicates the good reliability of the questionnaire. Also, factor analysis tests and techniques, Pearson’s correlation, one-way analysis of variance (ANOVA), and Sheffe's post hoc test were used to analyze the questionnaire data, and GIS was used to prepare the maps. Research FindingsThe results of the factor analysis show that the most important component affecting resilience in the studied area is the sense of place belonging. On the other hand, the results obtained from Pearson's correlation show that in the Karimabad neighborhood, the highest relationship exists between the two variables of security and environmental health and the sense of place belonging. Also, in the Qasimabad neighborhood, the relationship between the components of individual knowledge and skill and the improvement of the economic situation is the strongest. In the Shirabad neighborhood, like Karimabad, the relationship between the two variables of security and health and the sense of belonging to the place is the most intense. The result of the analysis of variance, which was done to compare the neighborhoods in terms of resilience indicators, shows that there is a significant difference between the neighborhoods under the study in terms of the three variables of access, place belonging, and security and environmental health. Thus, the neighborhood of Karimabad, compared to the two neighborhoods, has a more favorable relative situation. Discussion of Results and ConclusionThe results of the spatial analysis indicate that the Karimabad neighborhood has a better condition than the other two neighborhoods (Qasimabad and Shirabad). The reason for this can be found in the implementation of regeneration programs. For example, if we look at the descriptive statistics, this neighborhood has fewer residents who do not have ownership documents. Therefore, by granting ownership documents and recognizing these neighborhoods, and on the other hand, by carrying out regeneration measures in different dimensions, it is possible to improve the resilience of the target neighborhoods

Pathology of urban management in the ethnic city (Case study: Nourabad city, Lorestan province)

Objective: Promotion of villages to cities at the center of the settlement of nomads and villagers have shaped a particular type of city in contemporary Iran. These cities have become the destination for nomadic and rural migration from the surrounding areas and with features such as rapid population growth, the weakness of political culture and social-spatial segregation, they have been caught up in a cycle of inefficiencies in urban management. Accordingly, the main purpose of the present paper is the pathology of urban management in the ethnic city. Methods: Current paper is analytical–descriptive according to nature. Requirement data and information were gathered by documentary and field methods. The population of the study consisted of citizens of Nourabad city and urban planners and specialists including municipality staffs, mayors and counselors of Nourabad municipality. According to Cochran''''s formula and financial and time constraints of the research, the sample size of the study consisted of 200 citizens and 60 urban management experts in the city of Nourabad. Results: The results of T-test indicate that, in terms of local residents, two factors of ethnicity and religious affiliation are significantly the most important factors affecting the way citizens choose the council members. In addition, according to respondents, lobbying and ethnicity were the most important measures in selecting the mayors. Citizens'''' satisfaction with the performance of Islamic councils in Nourabad city was at a low level and more than 68% of respondents expressed their dissatisfaction with the performance of the councils. The analysis of the opinions of mayors, counselors and employees of the municipality indicates that members of the city council interfere in the municipal administration in various ways, such as installing and disposing of personnel, interfering in the choice of the contractor, directing development projects to particular parts of the city. Conclusion: In a feedback process, the council derived from the socio-spatial structure based on ethnicity has led to the choice of the mayor on the basis of individual and ethnic interests and thereby, through interference with the municipal administration, has provided the ground for the inefficiency of urban management

Long-term effect on foot and ankle donor site following vascularized fibular graft resection in children

This study was carried out to evaluate the long-term effect on the donor side of the foot and ankle following vascularized fibular graft resection in children. Eight patients underwent resection of the fibula for the purpose of a vascularized fibular graft by a surgical team who practiced leaving at least 6 cm residual distal fibula. The age of these children at the time of surgery was between 3 and 12 years. They were reviewed between 3 and 12 years after surgery. Two patients who underwent resection of the middle shaft of the fibula at 3 and 5 years of age developed abnormal growth of the distal tibia, leading to ankle valgus. They were treated with growth modulation of the distal tibial physis and supramalleolar osteotomy with tibiofibular synostosis. Another patient who underwent the entire proximal fibula resection at the age of 6 years had developed hindfoot valgus because of weakness of the tibialis posterior muscle. He required talonavicular fusion and flexor hallucis to tibialis posterior muscle transfer. Patients operated at the age of older than 8 years neither had ankle nor hindfoo

A Comparison of Early Side-Effects of Short-Course and Long-Course Radiotherapy in Rectal Cancer

Background: The variety of neoadjuvant treatments concerning rectal cancer has led to acute complications. The present study aimed to evaluate and compare the acute complications of short-course (SC) and long-course (LC) radiotherapy. Method: We studied 100 patients suffering from rectal cancer, who referred to Nemazee Hospital before their surgery, in this cross-sectional study. The patients were divided into two categories: SC (25 grays radiotherapy at 5 fractions in 5 days) and LC (chemoradiotherapy with a dose of 45-50.4 grays in 25- 28 fraction in 5-6 weeks with concurrent Capecitabine (825 mg / m2) twice daily and five days a week). Subsequently, we evaluated them for acute complications in the SC group 10-14 days after the end of the treatment and in the LC group at intervals of the treatment, the end of it and 2 weeks afterwards. Results: In the LC group compared to the SC group, the percentage of patients with grade 1 diarrhea, grade 2 colitis and grade 1 cystitis at the end of the treatment was statistically different (p 0.05). Conclusion: This study implied that there were no significant differences regarding severe acute complication between the two groups

Experimental investigation on the influence of temperature on the adsorption of henna extract on koalinite in reducing surfactant adsorption

The adsorption ability of henna extract as an environment-friendly and easily available sacrificial agent was investigated. Fourier transform infrared-attenuated total reflectance (FTIR-ATR) was used to characterized henna extract and kaolinite. The adsorption of henna extract on kaolinite was done using Ultraviolet-visible spectroscopy (UV-Vis). The influence of temperature on the henna extract adsorption on kaolinite was studied. The mechanisms of the adsorption process were interpreted. Also, henna extract performances in reducing the adsorption of surfactant were assessed. The outcome shows that henna extract adsorption on kaolinite was decreased with increasing temperature. The adsorption value decreased from 7.88 to 7.04 mg/g from the temperature of 25oC to 75oC due to the increased of the kinetic energies of the henna extract molecules. A reduction of 38% of surfactant adsorption was observed and showed a profound drop in the adsorption of surfactant in the presence of henna extract suggesting a possibility to be utilized as a sacrificial agent in reducing the adsorption of surfactant

Pharmacological potential of Sargassum sp. of west coast of Maharashtra Kunkeshwar, India

A promising plant group that is important in medicine is the seaweed. In this investigation, we have focused on the pharmacological prospects of brown algae (Sargassum sp). Nutraceuticals refer to products that may combine pharmacological and nutrition. We have collected the plant material close to Kunkeeshwar in Sindhudurg, Maharashtra’s western coast. We focused on the Physicochemical Attributes of Sargassum sp., and the study found that the ash value (41 ± 0.67), moisture content (1.33 ± 0.038), alcohol-soluble extractive value (1.5 ± 0.030), moisture content (1.33 ± 0.038), and total cash value (41 ± 0.67) are all stated in (%).The GCMS findings, which demonstrate that a total of 25 chemicals were discovered in the aqueous extract of Sargassum sp., also represent their nutritional profile. All of these substances have chromatograms that can be observed.1-Hexyl-2-nitrocyclohexane is the substance with the second-largest retention duration and relative areas, followed by n-hexadanoic acid. The presence of ocladecanoic acid was later determined. The explanation for how the activity is concentration-dependent is pharmacological activity, particularly antioxidant activity as shown by the DPPH assay.2μg/mL is -1545.4 ± 0.05. as a minimum. and at (32 g/mL is 7.67 ± 0.05) is the highest. The antifungal activity of Candida albicans (12.8 mm) and Aspergillus niger (14.4 mm) both exhibit zone inhibition when tested against two distinct pathogen however, the antibacterial activity of three different bacteria demonstrates that Staphylococcus aureus (12 mm), Bacillus subtilis (10 mm), Proteus mirabilis (12.8 mm), and Escherichia. coli are all zone inhibited (13mm). Brown algae offer the greatest potential for human health nutrition, while pharmacological analysis is helpful for therapeutic application, according to the overall analysis