Comparison of High Frequency Detailed Generator Models for Partial Discharge Localization

Hassan Hosseini, S.M.,Hosseini Bafghi, S.M. The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.4

This paper presents partial discharge localization in stator winding of generators using multi-conductor transmission line (MTL) and RLC ladder network models. The high-voltage (HV) winding of a 6kV/250kW generator has been modeled by MATLAB software. The simulation results of the MTL and the RLC ladder network models have been evaluated with the measurements results in the frequency domain by applying of the Pearson’s correlation coefficients. Two PD generated calibrator signals in kHz and MHz frequency range were injected into different points of generator winding and the signals simulated/measured at the both ends of the winding. For partial discharge localization in stator winding of generators is necessary to calculate the frequency spectrum of the PD current signals and then estimate the poles of the system from the calculated frequency spectrum. Finally, the location of PD can be estimated. This theory applied for the above generator and the simulation/measured results show the good correlation for PD Location for RLC ladder network and MTL models in the frequency range of kHz (10kHz<f<1MHz) and MHz (1MHz<f<5MHz) respectively.

Lipid-Lowering Effects of Concurrent Training and Green Tea Consumption in Overweight Women

Zahra Hosseini,Hadi Ghaedi,Mozhgan Ahmadi,Seyed Ali Hosseini 대한비만학회 2020 The Korean journal of obesity Vol.29 No.4

Background: Exercise conducted simultaneously with the consumption of herbal supplements is one of the suggested methods for controlling obesity and its complications. The present study sought to investigate the lipid-lowering effects of concurrent training and green tea (GT) consumption in overweight women. Methods: In this quasi-experimental study, 40 overweight women were selected and stratified into four groups: control (C), GT, concurrent training+placebo (TP), and concurrent training+GT (three tablets containing 500 mg of GT per week; T+GT) groups. Both the TP and T+GT groups performed exercise three sessions per week for 8 weeks. Fasting blood samples were collected before and 48 hours after the last training session. Results: Low-density lipoprotein cholesterol levels in the T+GT (P=0.03) and TP (P=0.001) groups were significantly decreased relative to in the GT group and were significantly decreased in the T+GT group relative to in the TP group (P=0.001). Meanwhile, high-density lipoprotein cholesterol levels in the T+GT group were significantly increased as compared with in the GT (P=0.01), TP (P=0.03), and C (P=0.04) groups. Finally, total cholesterol levels in the T+GT group were decreased significantly as compared with in the TP, GT, and C groups (P=0.001) and triglyceride levels in the T+GT, TP, and GT groups were significantly increased as compared with in the C group (P=0.001). Conclusion: Exercise performed simultaneously with GT consumption in comparison with either alone has a greater effect on improving the lipid profile in overweight women.

Enhancing performance of polyacrylonitrile membranes for pervaporation dehydration of ethanol by tailoring morphology and process parameters

Seyed Mohammad Hosseini Nejad,Amir Hossein Mostafavi,Seyed Saeid Hosseini,Haoze Zeng,Lu Shao 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.10

Development of high performance membranes for ethanol (EtOH) dehydration constitutes one of the main applications of pervaporation technology. In the present study, the properties of membranes derived from PAN were examined for this purpose. Heat treatment and variation of operational parameters were explored as viable strategies for enhancing the process performance. The characteristics of the membranes including morphology, thickness and sorption behavior were investigated in detail to identify their roles. Application of heat treatment with regards to polymer Tg resulted in membranes with distinct morphological and sorption characteristics. Increase in operational temperature was found effective for optimizing the opposing trends of permeate flux and separation factor. The maximum PSI value for the pristine PAN membrane was 5,564.0 g·m−2h−1, which occurred for operation at 50 °C. Also, application of heat treatment led to drop in flux and increase in separation factor by which PSI reached 41.3 kg·m−2h−1, which was 7.5 times than that of pristine PAN membrane. This study demonstrates successful implementation of facile strategies for tuning the characteristics and performance of membranes derived from PAN for efficient dehydration of EtOH via pervaporation process.

Generalized coupled non-Fickian/non-Fourierian diffusion- thermoelasticity analysis subjected to shock loading using analytical method

Seyed Amin Hosseini,Mohammad Hossein Abolbashari,Seyed Mahmoud Hosseini 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.60 No.3

In this article, the generalized coupled non-Fickian diffusion-thermoelasticity analysis is carried out using an analytical method. The transient behaviors of field variables, including mass concentration, temperature and displacement are studied in a strip, which is subjected to shock loading. The governing equations are derived using generalized coupled non-Fickian diffusion-thermoelasticity theory, which is based on Lord-Shulman theory of coupled thermoelasticity. The governing equations are transferred to the frequency domain using Laplace transform technique and then the field variables are obtained in analytical forms using the presented method. The field variables are eventually determined in time domain by employing the Talbot technique. The dynamic behaviors of mass concentration, temperature and displacement are studied in details. It is concluded that the presented analytical method has a high capability for simulating the wave propagation with finite speed in mass concentration field as well as for tracking thermoelastic waves. Furthermore, the obtained results are more realistic than that of others.

Comparison of High Frequency Detailed Generator Models for Partial Discharge Localization

S. M. Hassan Hosseini,S. M. Hosseini Bafghi 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.4

This paper presents partial discharge localization in stator winding of generators using multi-conductor transmission line (MTL) and RLC ladder network models. The high-voltage (HV) winding of a 6kV/250kW generator has been modeled by MATLAB software. The simulation results of the MTL and the RLC ladder network models have been evaluated with the measurements results in the frequency domain by applying of the Pearson’s correlation coefficients. Two PD generated calibrator signals in kHz and MHz frequency range were injected into different points of generator winding and the signals simulated/measured at the both ends of the winding. For partial discharge localization in stator winding of generators is necessary to calculate the frequency spectrum of the PD current signals and then estimate the poles of the system from the calculated frequency spectrum. Finally, the location of PD can be estimated. This theory applied for the above generator and the simulation/measured results show the good correlation for PD Location for RLC ladder network and MTL models in the frequency range of kHz (10kHz<f<1MHz) and MHz (1MHz<f<5MHz) respectively.

Mechanical Properties of Concrete by Use of Astragalus Resin

Seyed, Jamal Aldin Hosseini(세예드 자말 알딘 호세이니),Hwang, Hyeon-Jong(황현종),Jila, Raeiji(질라래이지),Fatemeh, Sadat Hosseini(파테메 사다트 호세이니) 한국콘크리트학회 2021 한국콘크리트학회 학술대회 논문집 Vol.33 No.2

본 연구에서는 이란 북부지역에서 흔히 볼 수 있는 황기수지를 가소제로 사용하여 콘크리트의 기계적 특성을 조사하였다. 황기수지는 시멘트 함량의 1 %∼3 %의 투입량을 사용하였다. 콘크리트의 슬럼프, 단위 중량 및 경화 특성(7일 및 28일 압축 강도)과 같은 신선한 콘크리트의 기계적 특성을 실험적으로 연구하였다. 시험 결과 콘크리트의 작업성이 향상되었으며, 시멘트 함량의 2% 배합시 콘크리트는 레올로지, 작업성, 압축강도가 증가하였다. This study investigated the mechanical properties of concrete by use of Astragalus resin which is frequently found in the north of Iran, as a plasticizer. The Astragalus resin was used with a dosage of 1 % to 3% of cement content. The mechanical properties of fresh concrete, such as slump, unit weight, and hardened properties of concrete (7-day and 28-day compressive strength). The test results indicated that the Astragalus resin improved the workability of fresh concrete. The concrete containing resin by 2% of cement content exhibited higher rheology, workability, and compressive strength.

Household Overcrowding in Iran, a Low-middle-income Country: How Major of a Public Health Concern Is It?

Hosseini, Leila Jansar,Samadi, Ali Hussein,Woldemichael, Abraha,Gharebelagh, Masoumeh Najafi,Rezaei, Satar,Rad, Enayatollah Homaie The Korean Society for Preventive Medicine 2021 Journal of Preventive Medicine and Public Health Vol.54 No.1

Objectives: Household overcrowding (HC) can contribute to both physical and mental disorders among the members of overcrowded households. This study aimed to measure the status of HC and its main determinants across the provinces of Iran. Methods: Data from 39 864 households from the 2016 Iranian Household Income and Expenditures Survey were used in this study. The Equivalized Crowding Index (ECI) and HC index were applied to measure the overcrowding of households. Regression models were estimated to show the relationships between different variables and the ECI. Results: The overall, urban, and rural prevalence of HC was 8.2%, 6.3%, and 10.1%, respectively. The highest prevalence of HC was found in Sistan and Baluchestan Province (28.7%), while the lowest was found in Guilan Province (1.8%). The number of men in the household, rural residency, the average age of household members, yearly income, and the household wealth index were identified as the main determinants of the ECI and HC. Conclusions: The study demonstrated that the ECI and HC were higher in regions near the borders of Iran than in other regions. Therefore, health promotion and empowerment strategies are required to avoid the negative consequences of HC, and screening programs are needed to identify at-risk families.

Implementation of a micro-meso approach for progressive damage analysis of composite laminates

Hosseini-Toudeshky, H.,Farrokhabadi, A.,Mohammadi, B. Techno-Press 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.43 No.5

The mismatch of ply orientations in composite laminates can cause high interlaminar stress concentrations near the free edges. Evaluation of these interlaminar stresses and their role in the progressive damage analysis of laminates is desirable. Recently, the authors developed a new method to relate the physically based micromechanics approach with the meso-scale CDM considering matrix cracking and induced delamination. In this paper, the developed method is applied for the analysis of edge effects in various angle-ply laminates such as $[10/-10]_{2s}$, $[30/-30]_{2s}$ and $[45/-45]_{2s}$ and comparing the results with available traditional CDM and experimental results. It is shown that the obtained stress-strain behaviors of laminates are in good agreement with the available experimental results and even in better agreement than the traditional CDM results. Variations of the stresses and stiffness components through the laminate thickness and near the free edges are also computed and compared with the available CDM results.

Application of various types of recycled waste materials in concrete constructions

Hosseini, Seyed Azim Techno-Press 2020 Advances in concrete construction Vol.9 No.5

Studies have proved that the mechanical properties of concrete, suddenly is dropped off with employing waste materials as replacements. The effectiveness of fibre addition on the structural stability of concrete has been indicated in recent investigations. There are different waste aggregates and fibres as plastic, rubber tire, coconut, and other natural wastes, which have been evaluated throughout the last decades. The fibres incorporation has a substantial effect on the properties of concrete mix subjected to different loading scenarios. This paper has reviewed different types of wastes and the effect of typical fibres including Poly Ethylene Terephthalate (PET), rubber tire, and waste glass. Furthermore, waste plastic and waste rubber has been especially studied in this review. Although concretes containing PET fibre revealed a reduction in compressive strength at low fibre fractions, using PET is resulted to micro-cracking decrement and increasing flexibility and flexural strength. Finally, according to the reviews, the conventional waste fibres are well-suited to mitigated time-induced damages of concrete and waste fibres and aggregates could be a reliable replacement for concrete.

Numerical Simulation of Vortex Induced Vibration of A Flexible Cylinder

Hosseini, Mojtaba,Ashrafi, Hamid reza,Beiranvand, Peyman,Dehestani, Ahmad,Dehestani, Kiuomars Korean Society for Fluid machinery 2017 International journal of fluid machinery and syste Vol.10 No.4

Numerical simulations of vortex-induced vibration of a three-dimensional flexible Cylinder under uniform turbulent flow are calculated when Reynolds number is $1.35{\times}104$. In order to achieve the vortex-induced vibration, the three-dimensional unsteady, viscous, incompressible Navier-Stokes equation and LES turbulence model are solved with the finite volume approach, the Cylinder is discretized according to the finite element theory, and its dynamic equilibrium equations are solved by the Newmark method. The fluid-Cylinder interaction is realized by utilizing the diffusion-based smooth dynamic mesh method. Considering VIV system, the variety trends of lift coefficient, drag coefficient, displacement, vertex shedding frequency, phase difference angle of Cylinder are analyzed under different frequency ratios. The nonlinear phenomena of locked-in, phase-switch are captured successfully. Meanwhile, the limit cycle and bifurcation of lift coefficient and displacement are analyzed using trajectory, phase portrait and Poincare sections. The results reveal that: when drag coefficient reaches its minimum value, the transverse amplitude reaches its maximum and the "lock-in" begins simultaneously. In the range of "lock-in", amplitude decreases gradually with increasing of frequency ratio. When lift coefficient reaches its minimum value, the phase difference, between lift coefficient and lateral displacement, undergoes a suddenly change from the "out-of-phase" to the "in-phase" mode. There is no bifurcation of lift coefficient and lateral displacement occurred in three dimensional flexible Cylinder submitted to uniform turbulent flow.