• Title/Summary/Keyword: destruction grade

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Comparative Exergy Analysis of Kalina and Organic Rankine Cycles for Conversion of Low-Grade Heat Source (저등급 열원의 변환을 위한 칼리나 사이클과 유기 랭킨 사이클의 엑서지 성능의 비교 해석)

  • KIM, KYOUNG HOON;JUNG, YOUNG GUAN;KO, HYUNG JONG
    • Transactions of the Korean hydrogen and new energy society
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    • v.31 no.1
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    • pp.105-111
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    • 2020
  • The organic Rankine cycle (ORC) and the Kalina cycle system (KCS) are being considered as the most feasible and promising ways to recover the low-grade finite heat sources. This paper presents a comparative exergetical performance analysis for ORC and Kalina cycle using ammonia-water mixture as the working fluid for the recovery of low-grade heat. Effects of the system parameters such as working fluid selection, turbine inlet pressure, and mass fraction of ammonia on the exergetical performance are parametrically investigated. KCS gives lower lower exergy destruction ratio at evaporator and higher second-law efficiency than ORC. The maximum exergy efficiency of ORC is higher than KCS.

Significance of Intracranial Pressure Monitoring in Early Surgery for Poor-Grade Aneurysm Patients (중증 뇌동맥류 환자의 조기 수술에 있어서 뇌압 측정의 중요성)

  • Kim, Sang Su;Kim, Jong Moon;Kang, Sung Don
    • Journal of Korean Neurosurgical Society
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    • v.30 no.4
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    • pp.425-429
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    • 2001
  • Objective : Patients with poor grade aneurysm usually present with increased intracranial pressure(ICP), even those without an intracranial clot. Based on this fact, the present study investigated a significance of intracranial pressure monitoring in those patients. Patients and Methods : A total of 60 patients with Hunt and Hess Grade IV(50 patients) or V(10 patients) were treated for aneurysmal subarachnoid hemorrhage(SAH) during a 3-year-period, and intraparenchymal ICP was measured in the majority, immediately after arrival to the emergency room. Early surgery including intraoperative ventriculostomy was undertaken within 3 days after SAH. An ultraearly surgery was performed without preceding angiogram or ICP monitoring in patients with large sylvian hematomas, highly suggestive of middle cerebral artery aneurysm. Outcomes were assessed by the Glasgow Outcome Scale(GOS) at 6 months. Results : In overall, favorable outcome(GOS scores 1-2) was seen in 27(54.0%) of admission Grade IV and 1(10.0%) of admission Grade V patients. Of the 38 surgical patients with preoperative ICP monitorings, 25 patients (80.6%) exhibiting ICP values of less than 40mmHg showed favorable outcome, however, no patients with ICP values above 40mmHg recovered(Fisher's exact test, p=0.0001). Conclusion : It is concluded that a preoperative ICP above 40mmHg before ventriculostomy indicate significant vital brain destruction as intractable intracranial hypertension, and Grade IV patients at admission with an ICP below 40mmHg can be of benefit from early surgical intervention while Grade V patients still remains unfavorable.

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Performance Characteristics Analysis of Evaporator in Ammonia-Water Rankine Cycle Based on Exergy and Entransy (암모니아-물 랭킨사이클의 증발기에서의 엑서지 및 엔트랜시 성능 특성 해석)

  • KIM, KYOUNG HOON;JUNG, YOUNG GUAN
    • Transactions of the Korean hydrogen and new energy society
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    • v.30 no.6
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    • pp.621-628
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    • 2019
  • The use of the ammonia-water zeotropic mixture as a working fluid in the power generating system has been considered as a proven technology for efficient recovery of low-grade heat sources. This paper presents a thermodynamic performance analysis for ammonia-water evaporator using low-grade heat source, based on the exergy and entransy which has been recently introduced as a physical quantity to describe the heat transfer ability of an object. In the analysis, effects of the ammonia mass fraction and source temperature of the binary mixture are investigated on the system performance such as heat transfer, effectiveness, exergy destruction, entransy dissipation, and entransy dissipation based thermal resistance. The results show that the ammonia mass concentration and the source temperature have significant effects on the thermodynamic system performance of the ammonia-water evaporator.

Evaluation of Impact Resistance of Steel Fiber and Organic Fiber Reinforced Concrete and Mortar

  • Kim, Gyu-Yong;Hwang, Heon-Kyu;Nam, Jeong-Soo;Kim, Hong-Seop;Park, Jong-Ho;Kim, Jeong-Jin
    • Journal of the Korea Institute of Building Construction
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    • v.12 no.4
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    • pp.377-385
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    • 2012
  • In this study, the Impact resistance of steel fiber and organic fiber reinforced concrete and mortar was evaluated and the improvement in toughness resulting from an increase in compressive strength and mixing fiber for impact resistance on performance was examined. The types of fiber were steel fiber, PP and PVA, and these were mixed in at 0.1, 0.5 and 1.0 vol.%, respectively. Impact resistance is evaluated with an apparatus for testing impact resistance performance by high-speed projectile crash by gas-pressure. For the experimental conditions, Specimen size was $100{\times}100{\times}20$, 30mm ($width{\times}height{\times}thickness$). Projectile diameter was 7 and 10 mm and impact speed is 350m/s. After impact test, destruction grade, penetration depth, spalling thickness and crater area were evaluated. Through this evaluation, it was found that as compressive strength is increased, penetration is suppressed. In addition, as the mixing ratio of fiber is increased, the spalling thickness and crater area are suppressed. Organic fibers have lower density than the steel fiber, and population number per unit area is bigger. As a result, the improvement of impact resistance is more significant thanks to dispersion and degraded attachment performance.

Rapidly Destructive Arthrosis of Knee Following Treatment of Crizotinib in a Patient with Non-Small-Cell Lung Cancer (비소세포폐암 환자에서 크리조티닙 치료 후 발생한 급속 파괴형 슬관절증)

  • Hwang, Jin Tae;Choi, Jae-Hyeong;Park, Chul-Hyun;Yoon, Kyung Jae;Lee, Yong-Taek;Do, Jong Geol
    • Clinical Pain
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    • v.19 no.2
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    • pp.120-123
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    • 2020
  • Rapidly destructive arthrosis is a rare syndrome characterized by narrowing of the joint space and rapid joint destruction within 6~12 months. A 62-year-old woman with anaplastic lymphoma kinase rearranged non-small-cell lung cancer presented with both knee pain and varus deformity. She was treated with crizotinib 500 mg/day for more than 2 years, with partial tumor response. Initial plain radiography showed Kellgren and Lawrence (K-L) grade 1. After 10 months, varus deformity was worsened and plain radiography aggravated to K-L grade 4 despite conservative treatment including activity modification. Diffuse synovitis with massive joint effusion and destruction of anterior cruciate ligament, medial meniscus, medial collateral ligament, and lateral collateral ligament were shown in magnetic resonance imaging. The patient was diagnosed with rapidly destructive arthrosis of knee and underwent a both total knee arthroplasty.

Criteria and Evaluation of Local Tidal Flats for Designating Conservation Sites in the Southwestern Coast of Korea (보호지역 지정을 위한 갯벌의 평가기준 개발과 전남 지역갯벌의 평가)

  • Chang, Jin-Ho
    • Journal of Environmental Science International
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    • v.17 no.12
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    • pp.1391-1402
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    • 2008
  • Designating conservation sites is needed for the preservation and management of tidal flats, and also objective criteria, by which preservation values of tidal flats can be evaluated, are required to designate conservation sites. A set of new evaluation criteria or tidal flats was suggested in this study. The criteria, based on six items including scarcity, diversity, naturalness, uniqueness, destruction possibility and preservation will, ave the advantages with which easy and economic assessments are possible by using basic data from the preceding studies. The evaluation results for the three different tidal lats (Muan, Jeungdo-1 and Jeungdo-2) in the southwestern coast of Korea reveal that all he tidal flats evaluated are classified into grade 2. The tidal flat which got the highest valuation score was Jeungdo-1 tidal flat (86.7), and the next was Muan (85.0) and Jeungdo-2 (82.5). The Jeungdo-2 tidal flat was superior in uniqueness and destruction possibility, and the Muan tidal flat was superior in diversity and naturalness.

Setting the Korean Mandarine Quality Standards based on Consumer Preference Survey (감귤의 소비자 선호도 조사를 통한 객관적 품질등급 기준 설정)

  • Ko, Seong-Bo;Hyun, Chang-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.8
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    • pp.3430-3438
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    • 2011
  • The purpose of this study is to set the Korean mandarine quality standards based on consumer preference survey. Until now the Korean mandarine's quality standards has been based on the fruit size. The Korean mandarine's quality in agricultural cooperative, citrus agricultural cooperative federation, and some agricultural corporation has been selected in accordance with its own brand of quality grade using a non-destruction sorting machine. But, setting the Korean mandarine's quality standards has been based on the convenient and routine method rather than the scientific and objective method, consumer's preference. According to the grade contents, the highest grade brand was required more than sugar $12^{\circ}Bx$ and less than acid 1.0% and the following grade brand was required more than sugar $11^{\circ}Bx$ and less than acid 1.0% uniformally. Thus, in this study, based on the consumers' preference of Korean mandarine, 4-level grades of sugar and 4-level grades of acidity were divided into the total 16-level grades. Based on them, 5-level grades were set.

Estimating the Economic Value of First-Grade Area in Ecological Nature Status (생태자연도 1등급지의 경제적 가치 추정)

  • Shin, Young Chul;Min, Dongki
    • Environmental and Resource Economics Review
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    • v.14 no.1
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    • pp.25-50
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    • 2005
  • This study estimates the willingness-to-pay (WTP) for avoiding the destruction of a first-grade ecological area by means of contingent valuation method. Specifically, we employ the dichotomous choice technique along with the follow-up questionnaires. Our analysis implies the yearly WTP per household for avoiding the destruction of the ecological area of 100,000 pyongs is 8,898 won with the 95% confidence interval of 6,611~11,976 won. We estimate the asset value of that area to be 1,707 billion won with the 95% confidence interval of 1,269 to 2,298 billion won. We also decompose the total value of the area into the value of direct (22%) and indirect (38.8%) use, the option value (19.9%) and the conservation value (21.3%). Although using these data for SEEA (the system of integrated environmental economic accounting) is bound by certain restrictions, one could employ our empirical findings as advisory information for decision making in the process of prior environmental review or for assessing the environmental impact.

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Changes in the area around Jangchungdan altar due to the Development of Residential Districts in Seoul from the 1920s to the 1930s (1920~30년대 장충단 인근 주택지 개발로 인한 지역 성격의 변화)

  • Lee, Kyung-Ah
    • Journal of architectural history
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    • v.27 no.4
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    • pp.17-30
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    • 2018
  • The purpose of this study was to determine changes in neighborhoods due to the development of residential districts around Jangchungdan(?忠壇) altar in Seoul from the 1920s to the 1930s. In the Joseon Dynasty, this area was a protected and sacred area to honor the spirit. The reputation of the area, however, turned into the place to play and take a rest and neighborhoods around Jangchungdan altar were developed as high-grade residential districts with the impression of suburbs during the Japanese colonial period. Residential districts were formed with the destruction of the Hanyang City Wall and the privatization of nation-owned forest, which were physical and symbolic boundaries of Seoul in the Joseon Dynasty.

Evaluation of Impact Resistance Performance of High Strength Concrete by Projectile Size and Compressive Strength (압축강도 및 비상체의 크기에 따른 고강도 콘크리트의 내충격 성능평가)

  • Kim, Hong-Sub;Kim, Gyu-Yong;Miyauchi, Hiroyukui;Nam, Jeong-Soo;Jeon, Young-Seok;Koo, Kyoung-Mo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.05a
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    • pp.7-10
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    • 2011
  • In this study, evaluation system of impact resistance performance is proposed. Compressive strength of concrete is 40, 60 and 80MPa. It evaluate impact resistance performance to use projectile 6, 7 and 8mm size. As a result, safety performance is more higher when the compressive strength is increased in. Compared with Hughes's formula, evaluation system of impact resistance performance is appropriated.

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