• Title/Summary/Keyword: Breaking capacity

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A Concept Analysis of the Caretaking Behavior for Children (양육행동 개념 분석)

  • Kim Soon-Goo
    • Child Health Nursing Research
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    • v.8 no.4
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    • pp.414-421
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    • 2002
  • The purpose of this study is to analyze the concept of caretaking behavior for children. This study adopts the methode of Walker and Avant in analysis. Based on the results of the study, the attributes, precedents, and consequences of caretaking behavior for children are follows ; 1. The affirmative attributes of caretaking behavior are affection binding, nutritional guidance, education, caring, protection moral training and acquisition of parents' role. The negative attributes of caretaking behavior are inconsistent moral training, incapability of affection binding and overprotection. 2. The precedent of caretaking behavior are postpartum contact with their babies, cognizance capacity of child-caretaking, economic support, level of preparation for child-caretaking and self-consciousness as parents. 3. The affirmative consequences of caretaking behavior are promotion of child growth and development, formation of maternal-infantile attachment, development of children sociality, satisfaction of parental role and reinforcement of relationship between the members of family. The negative consequences of caretaking behavior are burden and conflict to parental role, children's illness, role conflict and role stress among the members of the family and family breaking up.

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Fault Current Calculation and Coordination by IEC Standards (IEC 표준에 의한 고장전류 계산과 보호협조)

  • Son, Seok-Geum
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.12
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    • pp.6-12
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    • 2014
  • The safety and reliability of the power system short-circuit current, the short-circuit current depends on the failure to obtain the objective is to quickly eliminate the breaking capacity of the circuit-breaker selection of the cable, the insulation of electrical equipment and protective relay an important factor in determining the level correction and protective relay selection scheme to be meaningful. Standards used in the domestic circuit breaker is applied to the production of IEC standard, but the American National Standards (ANSI / IEEE) by NEMA specification of the fault current calculations and the application of the asymmetric coefficient Korea. Therefore, in this paper, the IEC 60909 standard IEC breaker fault current calculation method and the method for selection of system configurations reviewed and protection system for reviewing the configuration of various protective relays appropriate correction and the correction value is main protection, back-up protection the equipment so that the period of protection relay coordination to minimize accidents and accident protection to minimize interruptions proposed for cooperation.

Dynamic Analysis on the Closing Resistors of Gas Insulated Switchgear

  • Cho Hae-Yong;Lee Sung-Ho;Lim Sung-Sam
    • Journal of Mechanical Science and Technology
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    • v.20 no.10
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    • pp.1607-1613
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    • 2006
  • GIS (Gas Insulated Switchgear) is used in electric power system to insure non conductivity, breaking capacity and operating reliability. In the present study, dynamic analysis on the closing resistors of the GIS has bees carried out by the commercial dynamic analysis code COSMOS MOTION and 3-D modeling program SOLID WORKS. In order to find the minimum value of chatter vibration of closing resistors, the motion of moving and fixed resistor parts of closing resistors were simulated by varying the spring constant, the damping coefficient and the mass of moving and fixed resistor parts. The simulated results were compared with experimental results. The application of the results could reduce chatter vibration of closing resistors of the GIS. These data are also useful on the development of future model GIS with minimum chatter vibration for the determinations of the spring constant, the damping coefficient and mass of a moving part.

Development of a CFD Program for Cold Gas Flow Analysis in a High Voltage Circuit Breaker Using CFD-CAD Integration (CFD-CAD 통합해석을 이용한 초고압 차단기 내부의 냉가스 유동해석 프로그램 개발)

  • Lee, Jong-Cheol;An, Hui-Seop;O, Il-Seong;Choe, Jong-Ung
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.51 no.5
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    • pp.242-248
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    • 2002
  • It is important to develop new effective technologies to increase the interruption capacity and to reduce the size of a UB(Gas Circuit Breakers). Major design parameters such as nozzle geometries and interrupting chamber dimensions affect the cooling of the arc and the breaking performance. But it is not easy to test real GCB model in practice as in theory. Therefore, a simulation tool based on a computational fluid dynamics(CFD) algorithm has been developed to facilitate an optimization of the interrupter. Special attention has been paid to the supersonic flow phenomena between contacts and the observation of hat-gas flow for estimating the breaking performance. However, there are many difficult problems in calculating the flow characteristics in a GCB such as shock wave and complex geometries, which may be either static or in relative motion. Although a number of mesh generation techniques are now available, the generation of meshes around complicated, multi-component geometries like a GCB is still a tedious and difficult task for the computational fluid dynamics. This paper presents the CFD program using CFB-CAD integration technique based on Cartesian cut-cell method, which could reduce researcher's efforts to generate the mesh and achieve the accurate representation of the geometry designed by a CAD tools.

Evaluation of Acid-treated Fish Sarcoplasmic Proteins on Physicochemical and Rheological Characteristics of Pork Myofibrillar Protein Gel Mediated by Microbial Transglutaminase

  • Hemung, Bung-Orn;Chin, Koo Bok
    • Food Science of Animal Resources
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    • v.35 no.1
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    • pp.50-57
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    • 2015
  • Fish sarcoplasmic protein (SP) is currently dumped as waste from surimi industry and its recovery by practical method for being the non-meat ingredient in meat industry would be a strategy to utilize effectively the fish resource. This study was aimed to apply pH treatment for fish SP recovery and evaluated its effect on pork myofibrillar protein (MP) gel. The pH values of fish SP were changed to 3 and 12, and neutralized to pH 7 before lyophilizing the precipitated protein after centrifugation. Acid-treated fish SP (AFSP) showed about 4-fold higher recovery yield than that of alkaline-treated SP and water absorption capacity was also about 1.2-fold greater. Because of the high recovery yield and water absorption capacity, AFSP was selected to incorporate into MP with/without microbial transglutaminase (MTG). The effects of AFSP and MTG on the physicochemical and rheological characteristics of MP and MP gel were evaluated. MTG induced an increase shear stress of the MP mixture and increase the breaking force of MP gels. MP gel lightness was decreased by adding AFSP. MP gel with MTG showed higher cooking loss than that without MTG. A reduction of cooking loss was observed when the AFSP was added along with MTG, where the insoluble particles were found. Therefore, AFSP could be contributed as a water holding agent in meat protein gel.

A Study on Thermal Properties and Impurities Measurement of Semiconductive Shield by ICP-AES (ICP-AES에 의한 반도전재료의 불순물 측정 및 열적특성에 관한 연구)

  • Lee, Kyoung-Yong;Choi, Yong-Sung;Park, Dae-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07a
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    • pp.489-494
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    • 2004
  • In this paper, we investigated impurities content and thermal properties showing by changing the content of carbon black which is semiconductive materials for underground power transmission. Specimens were made of sheet form with the three of existing resins and the nine of specimens for measurement. Impurities content of specimens was measured by ICP-AES(Inductively Coupled Plasma Atomic Emission Spectrometer), and density of specimens were measured by density meter. And then heat capacity(${\Delta}H$) and melting temperature(Tm), specific heat(Cp) were measured by DSC(Differential Scanning Calorimetry). The dimension of measurement temperature was $0[^{\circ}C]\;to\;200[^{\circ}C]$, and rising temperature was $4[^{\circ}C/min]$. Impurities content was highly measured according to increasing the content of carbon black from this experimental result also density was increased according to these properties. Specially, impurities content values of the A1 and A2 of existing resins were measured more than 4000[ppm]. Heat capacity, melting temperature, and specific heat from the DSC results were simultaneously decreased according to increasing the content of carbon black. Because metallic impurities of carbon black having Fe, Co, Mn, A1 and Zn are rapidly passed kinetic energy increasing the number of times breaking during the unit time with the near particles according to increasing vibration of particles by the applied heat energy.

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Alkaline Pilot Processing for Recovery of Fish Muscle Protein and Properties of Recovered Protein (어육 단백질 회수를 위한 알칼리 Pilot 공정과 회수 단백질의 특성)

  • Jang, Young-Boo;Kim, Gun-Bae;Lee, Keun-Woo;Choi, Yeung-Joon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.8
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    • pp.1045-1050
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    • 2006
  • Optimum operation condition for pilot scale of alkaline processing for fish muscle was investigated by measuring protein solubility, yield, texture, and water-holding capacity. Recovered protein yield was 33.2% for whole fish and 61.8% for minced muscle. Optimum homogenized speed and time, using industrial scale homogenizer, were 3,000 rpm and 5 min, respectively. Limited centrifugal force of continuous cylinder type was 4,000 rpm for recovering soluble protein, and 2,000 rpm for recovering precipitated proteins. The pH control agents such as citric acid, sodium phosphate and calcium oxide decreased the breaking force and deformation of recovered protein gel. The breaking force and deformation of the recovered proteins were high compared to conventional surimi. The breaking force and deformation were decreased by addition of salt, starch and bovine plasma proteins. Whiteness of recovered protein gel was lower than that of conventional surimi. Alkaline processing greatly decreased nitrogen content and chemical oxygen demand in waste water. The results suggest that alkaline processing has a potential as industrial production for recovering the proteins from fish muscle.

Evaluation of the Inelastic Seismic Response of Curved Bridges by Capacity Spectrum Method using Equivalent Damping (등가감쇠비를 이용한 역량스펙트럼법에 의한 곡선교의 비탄성지진응답 평가)

  • Joe, Yang-Hee;Cho, Sung-Gook;Ma, Jeong-Suck
    • Journal of the Earthquake Engineering Society of Korea
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    • v.13 no.1
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    • pp.17-26
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    • 2009
  • The capacity spectrum method (CSM), which is known to be an approximate technique for assessing the seismic capacity of an existing structure, was originally proposed for simple building structures that could be modeled as single-degree-of-freedom (SDOF) systems. More recently, however, CSM has increasingly been adopted for assessing most bridge structures, as it has many practical advantages. Some studies on this topic are now being performed, and a few results of these have been presented as ground-breaking research. However, studies have until now been limited to symmetrical straight bridges only. This study evaluates the practical applicability of CSM to the evaluation of irregular curved bridges. For this purpose, the seismic capacities of 3-span prestressed concrete bridges with different subtended angles subjected to some recorded earthquakes are compared with a more refined approach based on nonlinear time history analysis. The results of the study show that when used for curved bridges, CSM induces higher inelastic displacement responses than the actual values, and that the gap between the two becomes larger as the subtended angle increases.

Analysis of the Recovery Behavior of SFCL According to Reclosing Operation (재폐로 동작에 따른 초전도 한류기의 회복성능 분석)

  • Ha, Kyoung-Hun;Cho, Yong-Sun;Kim, Deog-Goo;Choi, Hyo-Sang
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.5
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    • pp.1073-1077
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    • 2011
  • The breaking capacity of circuit breakers could be no more increased in the electric power system. This is because the fault current increases due to continuous increases in electric power demand and facilities. To solve the problem, it is necessary to come up with an alternative. The superconducting fault current limiter (SFCL) has received an attention among various alternatives. The SFCL effectively reduce a fault current in cooperation with a power circuit breaker. A various types of the SFCL are suggested and a study on them have been progressed. As a result of it, the SFCL can be applyed to the electric power system in the near future. But, a study on recovery behaviors of the SFCL is not enough for applying to the electric power system. If the superconducting elements do not completely recover to the superconducting state after fault operation, it might be a breakdown of the superconducting elements due to heavy power burden and it gives an bad influence on the working of other electric devices. Additionally, the distribution power system has reclosing operation such as open-0.3sec-closed/open-3min-closed/open procedure. So we need to study more about improvement of the recovery behaviors of the SFCL. In this paper, we analyzed the recovery behaviors of a flux-coupling type SFCL according to reclosing operation when a single line-to-ground fault occurred and we compared recovery behaviors of the SFCL with and without a neutral line between secondary reactors and superconducting elements. Also, the flux-coupling type SFCL has advantageous for increases of capacity by controlling the variation in turn ratios between two reactors. Consequently, when the number of turns of the secondary reactors increased, the power burden of the superconducting elements was bigger due to the increase of impedances of the secondary reactors. To distribute the power burden, two superconducting elements connected in series and the balanced quenching of the superconducting elements was induced by connecting a neutral line.

Effects of pH-treated Fish Sarcoplasmic Proteins on the Functional Properties of Chicken Myofibrillar Protein Gel Mediated by Microbial Transglutaminase

  • Hemung, Bung-Orn;Chin, Koo Bok
    • Food Science of Animal Resources
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    • v.34 no.3
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    • pp.307-315
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    • 2014
  • pH adjustment would be of advantage in improving the water holding capacity of muscle proteins. The objective of this study was to evaluate the addition of fish sarcoplasmic protein (SP) solution, which was adjusted to pH 3.0 or 12.0, neutralized to pH 7.0, and lyophilized to obtain the acid- and alkaline-treated SP samples, on the functional properties of the chicken myofibrillar protein induced by microbial transglutaminase (MTG). The solubility of alkaline-treated SP was higher than that of the acid counterpart; however, those values of the two pH-treated samples were lower than that of normal SP (p<0.05). All SP solutions were mixed with myofibrillar proteins (MP) extracted from chicken breast, and incubated with MTG. The shear stresses of MP with acid- and alkaline-treated SP were higher than that of normal SP. The thermal stability of MP mixture reduced upon adding SP, regardless of the pH treatment. The breaking force of MP gels with acid-treated SP increased more than those of alkaline-treated SP, while normal SP showed the highest value. The MP gel lightness increased, but cooking loss reduced, with the addition of SP. Smooth microstructure of the gel surface was observed. These results indicated that adjusting the pH of SP improved the water holding capacity of chicken myofibrillar proteins induced by MTG.