• Title/Summary/Keyword: 중량물 절단

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A Study on Segmentation Process of the K1 Reactor Vessel and Internals (K1 원자로 및 내부구조물 절단해체 공정에 대한 연구)

  • Hwang, Young Hwan;Hwang, Seokju;Hong, Sunghoon;Park, Kwang Soo;Kim, Nam-Kyun;Jung, Deok Woon;Kim, Cheon-Woo
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.17 no.4
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    • pp.437-445
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    • 2019
  • After the permanent shutdown of K1 in 2017, decommissioning processes have attracted great attention. According to the current decommissioning roadmap, the dismantling of the activated components of K1 may start in 2026, following the removal of its spent fuel. Since the reactor vessel (RV) and reactor vessel internal (RVI) of K1 contain massive components and are relatively highly activated, their decommissioning process should be conducted carefully in terms of radiological and industrial safety. For achieving maximum efficiency of nuclear waste management processes for K1, we present activation analysis of the segmentation process and waste classification of the RV and RVI components of K1. For RVI, the active fuel regions and some parts of the upper and lower active regions are classified as intermediate-level waste (ILW), while other components are classified as low-level waste (LLW). Due to the RVI's complex structure and high activation, we suggest various underwater segmentation techniques which are expected to reduce radiation exposure and generate approximately nine ILW and nineteen very low level waste (VLLW)/LLW packages. For RV, the active fuel region and other components are classified as LLW, VLLW, and clearance waste (CW). In this case, we suggest in-situ remote segmentation in air, which is expected to generate approximately forty-two VLLW/LLW packages.

Shape Optimization of Truss Structures with Multiobjective Function by α -Cut Approach (α -절단법에 의한 다목적함수를 갖는 트러스 구조물의 형상최적화)

  • Yang, Chang Yong;Lee, Gyu Won
    • Journal of Korean Society of Steel Construction
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    • v.9 no.3 s.32
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    • pp.457-465
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    • 1997
  • The Shape optimization makes it possible to reduce the weight of structure and cost then member sizing optimization. A vast amount of imprecise information is existed in constraints of the optimum design. It is very difficult and sometimes confusing to describe and to deal with the several criteria which contain fuzzy degrees of relatives importance. This paper proposed weighting strategies in the multiobjective shape optimization of fuzzy structural system by ${\alpha}$-cut approach. The algorithm in this research is numerically tested for 2-bar truss structure. The result show that. the user can choose the one optimum solution in practices as obtaining the optimum solutions according to the ${\alpha}$-cut approach, weight of volume and displacement.

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An Experimental Verification on the Development of an Innovative Diamond Wire Saw Cutting Technology (새로운 다이아몬드 와이어 쏘 절단 기술 개발에 관한 실험적 검증)

  • Park, Jong Hyup;Chu, Baeksuk
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.6
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    • pp.83-90
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    • 2018
  • This paper introduces a innovative diamond wire saw cutting technology and its experimental verification that can be utilized for cutting heavy structures. While conventional diamond wire saw cutting technologies such as water cooled cutting method and dry cutting method cause severe environmental problems due to generating massive concrete sludge or dust scattering, the proposed method can eliminate those problems considerably. Through extensive experiments using heavy structure test bed and real bridge pier structure, comprehensive analysis and comparative evaluation about various cutting methods were performed. As a result, the innovative diamond wire saw cutting method could achieve a similar cutting and cooling performance to the water cooled cutting method without generating concrete sludge and it showed an improved cutting and cooling performance to the dry cutting method without dust scattering. Consequently it is confirmed that the suggested cutting technology can be a promising environment-friendly alternative in the field of heavy structure dismantling.

Characteristics of Salted Radish Cubes at Different Season (계절별 절임 무의 특성)

  • Kim, Mee-Ree;Jhee, Ok-Hwa;Park, Han-Young;Chun, Byung-Moon
    • Korean Journal of Food Science and Technology
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    • v.34 no.1
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    • pp.1-7
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    • 2002
  • Characteristics (salt concentration, weight loss, soluble solid content, moisture content, and textural properties) of radish cube $(2{\times}2{\times}2\;cm)$ were evaluated during salting. Three different summer radish cultivars harvested in high land were immersed into 15% brine solution (radish : brine solution = 1 : 2) at $15^{\circ}C$ for 4 h. The time required to reach the optimum salt concentration (3%) was different among cultivars; 3 h for 'Bakbong', 4 h for 'Kwandong' and '92343'. Similar weight loss (about 24-26%) of salted radish cubes was found among cultivars. While the highest value of weight loss of salted radish cubes was observed with '92343', the lowest, 'Bakbong'. Hardness decreased during salting; the highest value of hardness was observer with 'Kwandong', the lowest, 'Bankbong'. The sample of '92343' has the lowest moisture content but has the highest soluble solid content and hardness, while 'Bakbong' has the highest moisture content, but has the lowest soluble solid content and '92343'. In separate experiments, seasonal variations in characteristics of salted radish cubes at optimum salt concentration (3%) were observed: for 'Bakbong', salt concentration, weight loss, soluble solid content, and hardness, and for 'Bakwang', salt concentration, weight loss, and hardness were higher in autumn cultivars than in spring or summer one, while moisture contents of both cultivars were higher in spring or summer cultivars than in autumn one.

Quality Characteristics of Minimally Processed Sweet-pumpkin during Storage (최소가공 단호박 (Cucurbita maxima Duchesne) 제품의 저장 중 품질 특성)

  • 이진숙;박연주;황태영;김인호;김수일;문광덕
    • Food Science and Preservation
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    • v.10 no.1
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    • pp.6-10
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    • 2003
  • The objective of this study was to investigate the effect of browning inhibitor and vacuum packaging on minimally processed sweet pumpkin. The browning inhibitor were lo/e of ascorbic acid, citric acid, NaCl, MgCl$_2$and their combination. For the minimal processing, sweet pumpkin was sliced and strip-cut followed by dipping in the solution of browning inhibitor. Effective browning inhibitors fer slice sweet pumpkin were ascorbic acid, NaCl and MgC1$_2$, and those fer thin strip were combination and ascorbic acid. The hardness of minimally processed sweet-pumpkin repeated increasing and decreasing and decreased in the final of storage. However the change pattern of hardness was different according to cutting method. Magnesium chloride treatment was generally high grade on sensory characteristics. Sweet pumpkin treated with citric acid was distinguished on carbon dioxide generation and oxygen exhaustion.

Performance Verification of Separation Nut Type Non-explosive Separation Device for Cube Satellite Application (큐브위성 적용을 위한 분리너트형 비폭발식 구속분리장치 인증모델의 성능검증)

  • Oh, Hyun-Ung;Lee, Myeong-Jae
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.10
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    • pp.827-832
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    • 2013
  • Heating wire cutting type separation mechanism has been widely used for cube satellite applications due to its design constraints such as small size of $10cm{\times}10cm{\times}10cm$ and light weight of less than 1kg. In addition, usage of pyro technic device is not allowed for cube satellite application. The conventional methods have some disadvantages of relatively small mechanical constraint force and the system complexity for the multi-deployable systems. In this paper, a separation nut type non-explosive separation mechanism has been proposed and investigated. The effectiveness of the design has been verified through the qualification tests of the mechanism.

Characteristics of Kakdugi Radish Cube by Autumn Cultivars during Salting (가을무 품종별 깍두기 무 절임 특성)

  • 김미리;박한용;전병문
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.1
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    • pp.25-31
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    • 2001
  • Characteristics (salt concentration, weight loss, soluble solid content, moisture content, pH, textural properties) of kakdugi radish cube (kakdugi radish, $2{\times}2{\times}2\;cm$) were evaluated during salting. Five different radish cultivars harvested in autumn were immersed into 10, 15 or 20% brine solution (radish : brine solution = 1 : 2) at $15^{\circ}C$ for 5hrs. The time required to reach the optimum salt concentration (3.0%) was different among cultivars; in the 10% brine solution, 5hr for 'Taeback', 4hr for 'Bakja', 3hr for 'Kwandong' and 'Bakbong', 2hr for 'Bagkwang'. Generally, it was observed that it took shorter salting time at higher concentration of brine solution. While the highest value of weight loss of kakdugi radish cubes was observed with 'Bagkwang', the lowest, 'Taeback'. There was a decrease of pH of kakdugi radish during salting; while 'Bakja' showes little change in pH, 'Bagkwang' shows large decrease of pH. Hardness and fracturability decreased during salting; the highest value of hardness was observed with 'Taeback', the lowest, 'Bagkwang' has the highest moisture content, the lowest soluble solid content and hardness. There was a similarity of characteristics of kakdugi radish cube between two cultivars, 'Taeback' and 'Bakja', as well as 'Bagkwang', and those of 'Kwandong' and 'Bakbong' were between two types of cultivars.

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Characteristics of Kakdugi Radish Cube by Spring Cultivars during Salting (봄무 품종별 깍두기 무의 절임 특성)

  • 김미리;오상희
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.5
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    • pp.819-825
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    • 2001
  • Characteristics (salt concentration, weight loss, soluble solid content, moisture content, pH, textural properties) of kakdugi radish cube (2$\times$2$\times$2 cm) were evaluated during salting. Four different radish cultivars harvested in spring were immersed into 5, 10 or 15% brine (radish : brine - 1 : 2) at 15$^{\circ}C$ for 5 hr. The time required to reach the optimum salt concentration (3.0%) was different among cultivars; in 10% brine solution, 5 hr for ‘Bakbong’and ‘9621’, and 4 hr ‘Bagkwang’ and ‘Housebommu’, in 15% brine, 3 hr for ‘Bakbong’and ‘9621’, and 2 hr for ‘Bagkwang’and ‘Housebommu’. While the highest value of weight loss of kakdugi radish cube was observed with ‘Bagkwang’, the lowest, ‘Bakbong’. There was a decrease of pH of kakdugi radish during salting ; while ‘Bakbong’ showed little change in pH, ‘Bakbong’and ‘Housebommu’ showed large decrease of pH. Hardness and fracturability decreased during salting; the highest value of hardness was observed with ‘Bagkwang’, the lowest, ‘Bagkwang’. ‘Bakbong’ has the lowest moisture content, but the highest soluble solid content, while ‘Bagkwang’and ‘Housebommu’ have the highest moisture content, but the lowest soluble solid content. There was a similarity of characteristics of kakdugi radish cube between two cultivars, ‘Bagkwang’and ‘Housebommu’.

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An Experimental Study on the Engineering Properties of Lightweight Aggregate Concrete (경량골재 콘크리트의 공학적 성질에 관한 실험적 연구)

  • ;R. N. Swanmy
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.39 no.1
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    • pp.75-82
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    • 1997
  • 건설기술과 산업의 발전에 따라 구조물은 대형화되어 가고, 건설공사의 급격한 팽창으로 골재 수용량이 급증함에 따라 천연골재자원은 점차 부족현상을 면치 못할 처지에 있다. 또한, 무리한 천연골재의 채취는 자연환경을 훼손시킬 뿐만 아니라 자연보호 측면에서도 심각한 공해문제로 대두되고 있어 공급량 부족현상은 날로 심화되고 있다. 이에 세계 몇몇 나라에세는 산업부산물을 이용한 골재 생산으로 공해예방과 폐기물 활용방법을 연구하고 있다. 산업부산물중 플라이 애쉬 생산량은 전 세계적으로 매년 약 2억여톤에 달하고 있으나 이중 일부만 활용되고 있는 실정이다. 이와같은 부산물을 활용하기 위한 일환으로 산업부산물인 PFA(Pulverized Fuel Ash)로 만든 인공경량골재의 년생산량이 영국은 600,000$m^3$, 미국은 300,000$m^3$이며, 매년 증가주세에 있다. 고성능 경량골재 콘크리트는 단위중량의 증가없이 내구성과 강도를 향상시켜 실용화 측면에서 경제적인 효과가 있으며, 플라이 애쉬로 만든 경량골재는 시멘트와의 친화력이나 접착면에서 우수한 것으로 알려져 있다. 본 시험에 사용한 골재는 플라이 애쉬로 만든 인공경량 조골재와 강모래이고, 결합제로서 프틀랜드 시멘트를 사용하였다. 부수적인 결합재로서는 플라이 애쉬, 슬래그, 실리카 흄을 사용하였으며, 고성능 경량골재 콘크리트를 개발코자 재령 28일과 180일의 압축강도가 각각 50MPa와 60MPa가 되도록 배합설계를 하였다. 본 연구에서는 플라이 애쉬, 슬래그, 시리카 흄과 같은 산업부산물을 혼입했을때 경량골재 콘크리트의 압축강도, 휨강도, 동탄성계수, 공극체적, 공극률, 단위중량, 공극 크기별 분포등의 변화를 실험적으로 구명하여 재반 구조용 콘크리트에 활용하기 위한 기초자료를 마련코저 한다.있어 특정한 발육단계의 난포 사망기전을 연구하기 어렵다. 또한 난포는 생체 내에서 다양한 호르몬을 동시에 분비하기 때문에 특정한 난소국부호르몬이 사망기전에 미치는 영향을 조사하기 힘든 점이 있다. 최근 들어 난포체외배양이 다양하게 개발되면서, 이러한 어려운 점을 극복할 수 있게 되었다. 본 논문은 각 발육단계의 난포를 절단해 체외배양하면서, apoptosis DNA 절단 현상을 이용하여 각종 난소국부 호르몬들이 난포발육단계별로 사망기전에 미치는 영향을 요약해 보였다. 난포는 발육하면서 점차 복잡한 호르몬 경로를 생존을 위해 필요로 한다. Prevulatory난포생존에 필요한 난소국부호르몬들은 early antral 단계의 난포에서는 그 미치는 영향이 감소되다가 preantral단계의 난포에서는 영향을 전혀 미치지 못했다. 단지 예외는 cGMP처리로써, 세포내 cGMP수준을 일정하게 유지시켜주는 것이 난포발육단계에 무관하게 생존에 중요한 인자로, 장래 연구는 난포 세포내의 cGMP수준을 조절하는 기작을 규명하는데 있을 것이다.인정되지 않았다. 7. 농지보전 처리구인 배수구와 초생수로구는 비처리구에 비해 낮은 침두 유출량과 낮은 토양유실량을 나타내었다.구보다 14% 절감되는 것으로 나타났다.작용하는 것으로 사료된다.된다.정량 분석한 결과이다. 시편의 조성은 33.6 at% U, 66.4 at% O의 결과를 얻었다. 산화물 핵연료의 표면 관찰 및 정량 분석 시험시 시편 표면을 전도성 물질로 증착시키지 않고, Silver Paint 에 시편을 접착하는 방법으로도 만족한 시험 결과를 얻을 수 있었다.째, 회복기 중에 일어나는 입자들의 유입은 자기폭풍의 지속시간을 연장시키는 경향을 보이며 큰 자기폭풍일수록 현저했다. 주상에서 관측된 이러한 특성은 서브스톰 확장기 활동이 자기폭풍의 발달과 밀접한 관계가

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Comparative analysis of status of safety accidents and importance-performance analysis (IPA) about precautions of safety accidents by employment type of industry foodservices in Jeonbuk area (전북지역 산업체급식소 조리종사자의 고용형태에 따른 안전사고 실태 및 안전사고 예방관리에 대한 중요도와 수행도 분석)

  • So, Hee;Rho, Jeong Ok
    • Journal of Nutrition and Health
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    • v.50 no.4
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    • pp.402-414
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    • 2017
  • Purpose: The purpose of the study was to evaluate the status of safety accidents and importance-performance analysis (IPA) between regular and non-regular employees in industry foodservices. Methods: The participants were regular employees (n = 119) and non-regular employees (n = 163) in industry foodservices in the Jeonbuk area. Demographic characteristics, status of safety accidents, safety education, and importance and performance status were assessed using a self-administered questionnaire. Results: Approximately 66.4% of regular employees and 53.4% of non-regular employees experienced safety accidents (p < 0.05). Types of safety accidents of regular and non-regular employees were mostly burns, and causes were mostly from their own negligence. Approximately 98.3% of regular employees and 95.1% of non-regular employees experienced safety education. Approximately 88.9% of regular employees and 96.8% of non-regular employees received safety education from dietitians. Approximately 41.9% of regular employees and 50.0% of non-regular employees had difficulty applying the contents of safety education due to lack of time during work. As a result of IPA, regular and non-regular employees were aware of the importance of the following and performed them well: 'Clean the floor of the work place', 'Arrange in the work area', 'Wear safety shoes', 'Check for heater cord', and 'Safety cooking when using oil'. On the other hand, they were not aware of the importance of the following and performed them insufficiently: 'Check for the MSDS', 'Aware of chemical signs', 'Wear protection gloves etc.', 'Do stretching exercise', and 'Using ancillary tools'. Conclusion: Therefore, it is necessary to improve the consciousness of dietitians for effective application of safety education contents, development of contents, especially MSDS, and related things.