Parameter estimation of electric power transformers using Coyote Optimization Algorithm with experimental verification

In this work, the Coyote Optimization Algorithm (COA) is implemented for estimating the parameters of single and three-phase power transformers. The estimation process is employed on the basis of the manufacturer's operation reports. The COA is assessed with the aid of the deviation between the actual and the estimated parameters as the main objective function. Further, the COA is compared with well-known optimization algorithms i.e. particle swarm and Jaya optimization algorithms. Moreover, experimental verifications are carried out on 4 kVA, 380/380 V, three-phase transformer and 1 kVA, 230/230 V, single-phase transformer. The obtained results prove the effectiveness and capability of the proposed COA. According to the obtained results, COA has the ability and stability to identify the accurate optimal parameters in case of both single phase and three phase transformers; thus accurate performance of the transformers is achieved. The estimated parameters using COA lead to the highest closeness to the experimental measured parameters that realizes the best agreements between the estimated parameters and the actual parameters compared with other optimization algorithms

Hybrid photovoltaic-thermoelectric generator powered synchronous reluctance motor for pumping applications

The interest in photovoltaic (PV) pumping systems has increased, particularly in rural areas where there is no grid supply available. However, both the performance and the cost of the whole system are still an obstacle for a wide spread of this technology. In this article, a hybrid photovoltaic (PV)-thermoelectric generator (TEG) is investigated for pumping applications. The electric drivetrain comprises a synchronous reluctance motor and an inverter. A control strategy for the drivetrain is employed to execute two main tasks: 1) driving the motor properly to achieve a maximum torque per Ampere condition and 2) maximizing the output power of the PV system at different weather conditions. This means that the conventional DC-DC converter is not used in the proposed system. Moreover, batteries, which are characterized by short life expectancy and high replacement cost, are also not used. It is found that the motor output power and the pump flow rate are increased by about 9.5% and 12% respectively when the hybrid PV-TEG array is used compared to only using PV array. Accordingly, the performance, cost and complexity of the system are improved. Measurements on an experimental laboratory setup are constructed to validate the theoretical results of this work

Solar array fed synchronous reluctance motor driven water pump : an improved performance under partial shading conditions

An improved performance of a photovoltaic (PV) pumping system employing a synchronous reluctance motor (SynRM) under partial shading conditions is proposed. The system does not include the dc-dc converter that is predominantly being utilized for maximizing the output power of the PV array. In addition, storage batteries are also not contained. A conventional inverter connected directly to the PV array is used to drive the SynRM. Further, a control strategy is proposed to drive the inverter so that the maximum output power of the PV array is achieved while the SynRM is working at the maximum torque per Ampere condition. Consequently, this results in an improved system efficiency and cost. Moreover, two maximum power point tracking (MPPT) techniques are compared under uniform and partial shadow irradiation conditions. The first MPPT algorithm is based on the conventional perturbation and observation (P&O) method and the second one uses a differential evolution (DE) optimization technique. It is found that the DE optimization method leads to a higher PV output power than using the P&O method under the partial shadow condition. Hence, the pump flow rate is much higher. However, under a uniform irradiation level, the PV system provides the available maximum power using both MPPT techniques. The experimental measurements are obtained to validate the theoretical work

Metastatic rhabdomyosarcoma of the thyroid gland, a case report

The thyroid gland is a known but an unusual site for metastatic tumors from various primary sites. Despite the fact that it is one of the largest vascular organs in the body, clinical and surgical cases have given an incidence of 3 % of secondary malignances of the organ. Nevertheless, thyroid metastases are not an exceptional finding at autopsy, they are encountered in 2 % to 24 % of the patients with malignant neoplasm. Soft tissue sarcomas metastatic to the thyroid are extremely rare as the majority of thyroid metastasis are caused by tumors of the kidneys, lungs, mammary glands, ovaries , and colon or by melanomas. We report a case of 22-years-old woman with right leg rhabdomyosarcoma metastatic to the thyroid gland

The Balanced Scorecard: Measures That Drive Performance Evaluation in Auditing Firms

© The Author(s) 2020. The purpose of this article is to establish a framework with its related measures for the development of a balanced scorecard (BSC) for auditing firms. A BSC was developed providing the detailed measures for performance evaluation comprising five key elements: learning and growth, clients, internal business processes, financials, and audit-related perspectives of corporate ethics. A survey was undertaken along with descriptive statistics and confirmatory factor analysis in four auditing firms, to assess the external auditors’ opinions for the proposed BSC measures. The results suggest that the development and use of the proposed BSC measures will enhance audit firms’ performance. Audit firms would have a better understanding of the various drivers of performance and strategies thereby creating a competitive advantage. The results are valuable to not only audit firms but also auditing oversight boards who could direct the design of their monitoring process by understanding performance systems in different size audit firms

Seroprevalence and “Knowledge, Attitudes and Practices” (KAPs) survey of endemic ovine brucellosis in Egypt

Additional file 1. Questionnaire used to collect shepherds’ knowledge, attitudes and practices on ovine brucellosis

An Apparatus for Measuring Heat Transfer Rate and Thermal Conductivity of Tubes جهاز لقياس معدل الانتقال الحرارى والتوصيلية الحرارية للمواسير

الملخصان معدل انتقال الحرارة والتوصيلية الحرارية هما من أکثر الخصائصالمباشرة والعملية لتقييم أداء المواد لنقل الحرارة ولا توجد طريقة واحدة يمکناعتمادها لقياس الخواص الحرارية للمواد ولکن تقتصر کل طريقة قياس لتحديدالتوصيلية الحرارية على نطاق محدد من قيم التوصيلية الحرارية ودرجاتالحرارة وأنواع معينة من المواد ولا يتم تطبيق طرق قياس التوصيلية الحراريةعلى عينات عشوائية ولکن لکل طريقة يلزم وجود عينة قياسية لها بتصميموأبعاد محددة ومثال على ذلک يتم استخدام عينة دائرية بقطر نصف بوصةمغطاة بطبقة من الجرافيت لتکون معتمة تمامًا في طريقة القياس من نوعيةFlash Laser . ولکن في طريقة Guarded Hot Plate يتم استخدام لوح علىشکل متوازى مستطيلات ذو دقة تصنيع عالية و بأبعاد محددة.بالإضافة إلى القيود السابقة ، تتطلب بعض التجارب معادلات رياضيةخاصة بالإضافة إلى معرفة تامة بالخواص الفيزيائية للمواد وقاعدة معلوماتتتطلب فى بعض الطرق جهاز حاسوب وتناقش هذه الورقة تحديد معدل نقلالحرارة والتوصيلية الحرارية للمواسير فى صورتها التجارية باستخدام جهازبسيط جديد يستخدم معادلة فورييرللاشکال الاسطوانية فى الاتجاه القطرىلتعيين التوصيلية الحرارية للمواسيروتم فى هذه الدراسة قياس معدل التدفق الحرارى عبر عينات مواسير منالکربون استيل ثم تحديد التوصيلية الحرارية لهذه العينات وکانت القيم التى تمقياسها مقاربة لتلک الموجودة بالمراجع المعتمدة والموصفة لهذه المواد فعلىسبيل المثال تم تعيين التوصيلية الحرارية لعينة من الکربون استيل SA 53 Bبقطر داخلى 39.5 مم وقطر خارجى 44.5 مم وبطول 38.5 مم وکانت قيمةالتوصيلية الحرارية 15,2 وات /متر.کلفن بحيود - 5% عن القيمة المذکورةبالمرجع الأمريکى ) American Power Research Institute EPRI ( وهى16 وات /متر.کلفن. وتم أيضا قياس التغير فى معدل التدفق الحرارى لعيناتمواسير عليها رواسب وکان الفارق فى معدل التدفق الحرارى للعينات قبل وبعدالتنظيف واضحا باستخدام الجهاز حيث کانت الزيادة فى معدل التدفق الحرارىبعد التنظيف حوالى 0,8 وات مما يعنى أن الجهاز له حساسية وأدائية عاليةتسمح بالمقارنة بين عينات المواسير للحصول على أعلى المراجل کفاءةAbstract-The heat transfer rate and thermal conductivity are the most direct and realistic properties for evaluating the performance of materials to transfer heat. Each measuring method for determining the thermal conductivity is limited for specific range of thermal conductivities, temperatures and specific types of materials. Thermal conductivity measuring methods are applied to standard samples. Those samples are supplied in a specific design with defined dimensions i.e. are not similar to the forms used in the industry. For example, a circular specimen of half inch finished with a layer of graphite to be completely opaque is used in the Flash Laser Method. But in Guarded Hot Plate method a highly precision plate with definite dimensions is used.In addition to previous limits, some experiments require certain mathematical equations as well as advanced knowledge of physical properties of materials. This paper discusses the determination of heat transfer rate and thermal conductivity of industrial pipes in its commercial configuration using a new simple apparatus which uses the known Fourier equation for radial direction heat transfer in cylindrical pipe.In this study, the rate of heat transfer was measured for samples of carbon steel tubes and then the thermal conductivity of these samples was determined. The values measured weresimilar to those found in the approved and standard referencesFor these materials, for example, the thermal conductivity of a sample of carbon SA 53B was determined with an internal diameter of 39.5 mm and an outer diameter of 44.5 mm and a length of 38.5 mm. The thermal conductivity value was 15.2 W / m2. It was 5% - the value indicated by the American reference Power Research Institute EPRI (16 W / m(.in addition to that the difference between the heat transfer rate of three samples before and after cleaning were studied, the difference was about 0.8 Watt which means that the device has high sensitivity and performance

Numerical estimation and experimental verification of optimal parameter identification based on modern optimization of a three phase induction motor

The parameters of electric machines play a substantial role in the control system which, in turn, has a great impact on machine performance. In this paper, a proposed optimal estimation method for the electrical parameters of induction motors is presented. The proposed method uses the particle swarm optimization (PSO) technique. Further, it also considers the influence of temperature on the stator resistance. A complete experimental setup was constructed to validate the proposed method. The estimated electrical parameters of a 3.8-hp induction motor are compared with the measured values. A heat run test was performed to compare the effect of temperature on the stator resistance based on the proposed estimation method and the experimental measurements at the same conditions. It is shown that acceptable accuracy between the simulated results and the experimental measurements has been achieved

ECO FRIENDLY ARCHITECTURE– A PRELUDE IN THE SULTANATE OF OMAN

In developed countries, the issue of green architecture and sustainability practices has been a major concern to building professionals and the community for many years. On the contrary, in the developing countries, the same issues are beyond public awareness. The Sultanate of Oman is one of the countries whose national economy is mainly based on nonrenewable energy resource, oil. In addition, the recent plummet in the price. of fossil fuel ushered Oman to seek alternative energy resources, and to think of adopting new policies. Unprecedented in the Third world, the national competition for Eco House Design was announced. Five examples of Eco Houses were designed and constructed during the first phase. This research aims to shed light on this remarkable Omani experience among the developing countries. The methodology of the research is incumbent on a theoretical foundation of previous related references analysis and a cross comparative case study. Other tools were used like interviews and site visits. The research succeeded in outlining the design criteria of eco-friendly architecture and clarifying the starting point taken by the Oman to adopt the green and issues. In addition, two examples of the Eco-houses in arid zones were provided. In the future, further steps have to be taken to re-direct the Omani society to adopt the green attitude

Preparation of Some Eco-friendly Corrosion Inhibitors Having Antibacterial Activity from Sea Food Waste

Chitosan is one of the important biopolymers and it is extracted from exoskeletons of crustaceans in sea food waste. It is a suitable eco-friendly carbon steel corrosion inhibitor in acid media; the deacetylation degree of prepared chitosan is more than 85.16 %, and the molecular weight average is 109 kDa. Chitosan was modified to 2-N,N-diethylbenzene ammonium chloride N-oxoethyl chitosan (compound I), and 12-ammonium chloride N-oxododecan chitosan (compound II) as soluble water derivatives. The corrosion inhibition efficiency for carbon steel of compound (I) in 1 M HCl at varying temperature is higher than for chitosan and compound (II). However, the antibacterial activity of chitosan for Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, and Candida albicans is higher than for its derivatives, and the minimum inhibition concentration and minimum bacterial concentration of chitosan and its derivatives were carried out with the same strain