Modified Transmission Line Protection Scheme in the Presence of SCC

Naeini, Ehsan Mostaghimi,Vaseghi, Behrouz,Mahdavian, Mehdi The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.2

Distance relay identifies the type and location of fault by measuring the transmission line impedance. However any other factors that cause miss calculating the measured impedance, makes the relay detect the fault in incorrect location or do not detect the fault at all. One of the important factors which directly changes the measured impedance by the relay is series capacitive compensation (SCC). Another factor that changes the calculated impedance by distance relay is fault resistance. This paper provides a method based on the combination of distance and differential protection. At first, faulty transmission line is detected according to the current data of buses. After that the fault location is calculated using the proposed algorithm on the transmission line. This algorithm is based on active power calculation of the buses. Fault resistance is calculated from the active powers and its effect will be deducted from calculated impedance by the algorithm. This method measures the voltage across SCC by phasor measurement units (PMUs) and transmits them to the relay location via communication channels. The transmitted signals are utilized to modify the voltage signal which is measured by the relay. Different operating modes of SCC and as well as different faults such as phase-to-phase and phase-to-ground faults are examined by simulations.

Unconfined Compressive Strength of Clayey Soils Stabilized with Waterborne Polymer

Seyed Abolhassan Naeini,Bahman Naderinia,Ehsan Izadi 대한토목학회 2012 KSCE Journal of Civil Engineering Vol.16 No.6

Improvement and stabilization of soils are widely used as an alternative to substitute the lacking of suitable material on site. Soils may be stabilized to increase strength and durability or to prevent erosion and dust generation. The use of nontraditional chemical stabilizers in soil improvement is growing daily. A new stabilizing agent was developed to improve the mechanical performance and applicability of clayey soils. In this study a laboratory experiment is conducted to evaluate the effects of plasticity index and waterborne polymer on the Unconfined Compression Strength (UCS) of clayey soils. The laboratory tests include sieve analysis,hydrometer, Atterberg limits, modified compaction and unconfined compression tests. Three clayey soils with different plasticity indexes were mixed with various amounts of polymer (2, 3, 4 and 5%) and compacted at the optimum water content and maximum dry density. The unstabilized and stabilized samples were subjected to unconfined compression tests to determine their strength at different curing times. The results of the tests indicated that the waterborne polymer significantly improved the strength behavior of unsaturated clayey soils. Also, an increase in plasticity index causes a reduction in unconfined compression strength.

Modified Transmission Line Protection Scheme in the Presence of SCC

Ehsan Mostaghimi Naeini,Behrouz Vaseghi,Mehdi Mahdavian 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.2

Distance relay identifies the type and location of fault by measuring the transmission line impedance. However any other factors that cause miss calculating the measured impedance, makes the relay detect the fault in incorrect location or do not detect the fault at all. One of the important factors which directly changes the measured impedance by the relay is series capacitive compensation (SCC). Another factor that changes the calculated impedance by distance relay is fault resistance. This paper provides a method based on the combination of distance and differential protection. At first, faulty transmission line is detected according to the current data of buses. After that the fault location is calculated using the proposed algorithm on the transmission line. This algorithm is based on active power calculation of the buses. Fault resistance is calculated from the active powers and its effect will be deducted from calculated impedance by the algorithm. This method measures the voltage across SCC by phasor measurement units (PMUs) and transmits them to the relay location via communication channels. The transmitted signals are utilized to modify the voltage signal which is measured by the relay. Different operating modes of SCC and as well as different faults such as phase-to-phase and phase-to-ground faults are examined by simulations.

Eco-friendly inorganic-organic bionanocomposite (Copper oxide - Carboxyl methyl cellulose - Guar gum): Preparation and effective removal of dye from aqueous solution

Ali Hosseinian Naeini,Mohammadreza Kalaee,Omid Moradi,Ramin Khajavi,Majid Abdouss 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.8

Biopolymers, such as Carboxyl methylcellulose (CMC) and Guar gum (GG), have attracted much attention. Herein, binary organic composite (Carboxyl methyl cellulose - Guar gum) and ternary inorganic-organic ecofriendlybionanocomposite (Copper oxide - Carboxyl methyl cellulose - Guar gum) with different wt% of CuO (1%,3%, and 5% denoted as CMC/GG/CuO-1, CMC/GG/CuO-3, and CMC/GG/CuO-5) were prepared. The CMC, GG,CuO, CMC/GG, CMC/GG/CuO-1, CMC/GG/CuO-3, and CMC/GG/CuO-5 were characterized by XRD, FTIR, SEM,and EDX and used to remove malachite green (MG) dye from water. The effect of operational parameters on theadsorption process was investigated in detail. The maximum dye capacity was 18.5mg/g. The isotherm data showedthe Freundlich isotherm, which indicated the non-uniformity of adsorption on the adsorbent surface. Pollutant removalfollowed the pseudo-second-order kinetics. Also, the thermodynamic study presented that adsorption was spontaneousand endothermic.

Mechanical Response of Buried High-density Polyethylene Pipelines under Normal Fault Motions

Seyed Abolhasan Naeini,Elham Mahmoudi,Mohammad Mahdi Shojaedin,Mohsen Misaghian 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.6

Permanent ground deformation is one of the most damaging hazards for continuous buried lifelines. In this paper, numerical models using a Finite Element Method (FEM) were developed to analyze the buried High-Density Polyethylene (HDPE) pipelines subjected to the normal fault motions. The numerical predictions, were compared with those from ASCE Guidelines and with the experimental results obtained from geotechnical centrifuge tests. Moreover, the paper focuses on the effects of the design parameters such as, pipe diameter and thickness, pipeline burial depth, friction angle and density of the soil surrounding the pipe on the maximum bending strain as well as bending strain distribution along the pipeline. The results show that numerical models using a finite element method could produce reasonable predictions. However, the maximum predicted bending strains from the ASCE Guidelines are larger than those from experiments. The pipe deformation mechanisms are also significantly influenced by variation in burial depth, pipe surface characteristics, and backfill type.

An experimental study on the effect of a novel nature-inspired 3D-serrated leading edge on the aerodynamic performance of a double delta wing in the transitional flow regime

Hamed Khodabakhshian Naeini,Mahdi Nili-Ahmadabadi,김경천 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.12

This study examines the effect of nature-inspired leading edge 3D serration on the aerodynamic performance of a 65/35-degree double delta wing. Force measurement experiments were conducted on a smooth-surface model and a model equipped with various combinations of serrated pieces in the leading edge area. Four symmetric different positions were examined in a low-speed wind tunnel. The transitional flow regime was applied with Reynolds numbers of 2×10 5 and angles of attack (AOA) of 0 to 36 degrees. Compared to the clean model, there is a notable enhancement in the maximum lift coefficient, especially for the pieces located at the apex and kink angle locations. However, when changing the combination of serrated leading edge (SLE) elements, a decline in C L can be seen at some AOAs, and adding more SLE pieces is not always useful. A drag reduction is also achieved by installing these elements, which provided a higher lift-to-drag ratio for all AOAs. Finally, the serrated leading edge postponed the stall angle of the double delta wing.

The Relationship between Serum Vitamin C and Uric Acid Levels, Antioxidant Status and Coronary Artery Disease: a Case-Control Study

( Aida Torkzaban ),( Amirmansour Alavi Naeini ),( Akbar Hassanzadeh ),( Mehrdad Namdari ) 한국임상영양학회 2020 Clinical Nutrition Research Vol.9 No.4

Coronary artery disease (CAD) is among the main causes of death in adults. Increase of oxidative stress and defects in antioxidant defense play a major role in endothelium performance and are affecting factors in the progress of atherosclerosis. The aim of this study was to measure serum levels of uric acid (UA) and vitamin C as well as the antioxidant status in patients with CAD, and compared them with those in healthy individuals. The present case-control study was performed on 44 cases and 44 controls. Demographic data and anthropometric indices were measured. The Food Frequency Questionnaire (FFQ) and International Physical Activity Questionnaire (IPAQ) were completed. After 12 hours of fasting,10 mL blood was sampled from the participants. Serum levels of UA, vitamin C, Total Antioxidant Capacity (TAC) and Malondialdehyde (MDA) were also measured. The data were finally analyzed by SPSS v22. A significant difference was observed between the groups in terms of UA and vitamin C. However, mean levels of MDA and TAC were not significantly different between groups. The differences between groups in terms of vitamin A, vitamin E, beta-carotene, zinc and selenium intakes were not significant either. A significant difference was detected between the groups in terms of vitamin C intake. Our results suggest that increase in UA and decrease in vitamin C in serum levels can be considered as risk factors for CAD patients. Due to a lack of any significant correlation between TAC and CAD risk in this study, further study with bigger sample size is needed.

Feasibility study on optimized process conditions in warm tube hydroforming

S. M. H. Seyedkashi,H. Moslemi Naeini,문영훈 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.7

Feasibility study has been performed to estimate the optimized process conditions in warm tube hydroforming based on the simulatedannealing optimization method. Precise prediction and control of process parameters play an important role in forming at warm conditions. Optimal pressure and feed loading paths are obtained for aluminium AA6061 tubes through the simulated annealing algorithm in conjunctionwith finite element simulations. Numerous axisymmetric geometries are investigated and the effects of expansion ratio, corner fillet tothickness ratio, and initial diameter to thickness ratio are studied. For the feasibility estimation, warm hydroforming experiments have beenconducted on aluminum AA6061 under optimal designed conditions. The results show that the optimization procedure used in this researchis a reliable and feasible tool in determination of optimal process conditions for the sound warm hydroforming process.

Preplant Optimum Nutrition of Olive (Olea europea) Trees with Fertilizer Channel Method (a New and Fantastic Method)

Ahmad Bolandnazar,Esmaeil Fallahi,Mohammad reza Naeini 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

Forming limit diagram of aluminum AA6063 tubes at high temperatures by bulge tests

Seyed Jalal Hashemi,Hassan Moslemi Naeini,Gholamhossein Liaghat,Rooholla Azizi Tafti,Farzad Rahmani 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.11

A free bulge test and ductile fracture criteria were used to obtain the forming limit diagrams (FLD) of aluminum alloy AA6063 tubesat high temperatures. Ductile fracture criteria were calibrated using the results of uniaxial tension tests at various elevated temperaturesand different strain rates through adjusting the Zener-Holloman parameter. High temperature free bulge test of tubes was simulated infinite element software Abaqus, and tube bursting was predicted using ductile fracture criteria under different loading paths. FLDs whichwere obtained from finite element simulation were compared to experimental results to select the most accurate criterion for prediction offorming limit diagram. According to the results, all studied ductile fracture criteria predict similarly when forming condition is close tothe uniaxial tension, while Ayada criterion predicts the FLD at 473 K and 573 K very well.