• Journal of Bio-Environment Control
• /
• v.28 no.4
• /
• pp.420-428
• /
• 2019

This study is the heating energy saving test of the high-bed strawberry crown heating system. The system consists of electric hot water boiler, thermal storage tank, circulation pump, crown heating pipe(white low density polyethylene, diameter 16mm) and a temperature control panel. For crown heating, the hot water pipe was installed as close as possible to the crown part after planting the seedlings and the pipe position was fixed with a horticultural fixing pin. In the local heating type, hot water at $20{\sim}23^{\circ}C$ is stored in the themal tank by using an electric hot water boiler, and crown spot is partially heated at the setting temperature of $13{\sim}15^{\circ}C$ by turning on/off the circulation pump using a temperature sensor for controlling the hot water circulation pump which was installed at the very close to crown of strawberry. The treatment of test zone consisted of space heating $4^{\circ}C$ + crown heating(treatment 1), space heating $8^{\circ}C$(control), space heating $6^{\circ}C$ + crown heating(treatment 2). And strawberries were planted in the number of 980 for each treatment. The heating energy consumption was compared between November 8, 2017 and March 30, 2018. Accumulated power consumption is converted to integrated kerosene consumption. The converted kerosene consumption is 1,320L(100%) for space $8^{\circ}C$ heating, 928L(70.3%) for space $4^{\circ}C$ + crown heating, 1,161L($88^{\circ}C$) for space $6^{\circ}C$ + crown heating). It was analyzed that space $4^{\circ}C$ + pipe heating and space $6^{\circ}C$ + crown heating save heating energy of 29.7% and 12% respectively compared to $8^{\circ}C$ space heating(control).

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.8 no.1
• /
• pp.39-45
• /
• 2005

In the situation which Russia's ratification of the Kyoto protocol at February,2004, ANNEX I nations must reduce GHG(Green House Gas) discharge rate from 2008 by 2012 to the reduction level at 1990. We introduce the CO₂ ocean sequestration that is one of promising method for getting the stable CO₂ concentration in the atmosphere. There are four categories : ocean transportation technique, ocean initial dissolution technique, ocean deep current evaluation technique, and ocean biological evaluation technique. In this paper, we carried out the fundamental numerical study on the ocean initial dissolution technique, when the Liquidized CO₂ is emitted at the deep ocean, It is very important to the dissolution rate of movable CO₂ interface because it Is directly impact to the ocean organism. In order to investigate the relation of the interface movement and rate of the dissolution, we develope CR(Computational Fluid Dynamics) code that was constructed by the finite volume method based on the unstructured mesh, and a droplet's boundary surface can move and one direction dissolution from disperse phase into continuous phase adopted as its physics be. This study clarifies hydrodynamic relation between solubility and movement of the droplet through the verification of the Cm code.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.7 no.1
• /
• pp.60-68
• /
• 2012

In this study, the manufacturing process of micro capsulized PCM (phase changing material) for thermal storage performance of latent heat was investigated to save energy during the use of buildings: i.e. use of melamine-type resin as the micro-capsule material and paraffin wax as the inner material that are together used in concrete walls. For the manufacturing process of the micro-capsulized PCM, the amount of SDS addition as surfactant was the key variable and the resulting thermal storage performance depended on the SDS amount. With increasing amount of SDS, the micro capsulation became much easier while the capsule surface became harder. The micro capsules became uniform at an optimum SDS addition. The addition of SDS also affected the thermal capacity: with increasing SDS amount, the heat storage and release tendency at melting point was more clearly manifested. The current investigation is part of a study under progress to explore the use of PCM in concrete walls to save building maintenance cost and energy.

• 대한불안의학회:학술대회논문집
• /
• 2004.06a
• /
• pp.185-213
• /
• 2004

우리는 살아가면서 흔히 개인적으로 극심한 스트레스를 겪거나 불행히도 어떤 뜻밖의 재난이나 큰 사고를 경험할 수 있다. 이런 외상적 사건들을 겪고 대부분의 사람들은 잘 극복할 수 있으나 일부 사람들은 심각한 의상 후 스트레스 반응을 보여 그런 외상이 지나감에도 불구하고 괴로운 기억 속에서 그것을 회상시키는 활동과 상황을 피하며 늘 불안한 마음으로 몸은 현재에 살고 있지만 마음은 실상 과거에 매달려 있고 과거의 고통 속에서 헤어 나오지 못하고 있다. 외상 후 스트레스 장애는 다른 불안 장애, 우울증처럼 흔한 질환으로 사회생활에 큰 지장을 주며 삶의 질을 손상시킨다. 그렇지만 외상을 당한 당사자들이 이런 이야기를 하기 꺼려하고, 이런 사람들을 진료실에서 종종 만날 수 있는 임상가들도 외상의 심각성과 외상 후 스트레스 장애에 대한 인식이 부족하여, 우리 주위에 많은 사람이 외상 후 스트레스 장애로 고생하고 있지만 외상 후 스트레스 장애로 진단되는 경우가 실제보다 훨씬 적다. 따라서 외상 후 스트레스 장애에 대한 평가를 배움으로써 더 많은 환자들을 정확히 진단하며 다른 질환과의 감별을 쉽게 할 수 있고, 환자들의 고통과 어려움이 과연 무엇인지 잘 알 수 있으며, 치료 표적과 치료 전략을 정하고, 치료 계획을 세우는 데 도움을 얻을 수 있다. 평가 방법으로는 구조화된 면담, 평가 척도, 정신 생리적 측정법, 치료자의 임상적인 결정 등이 있다. 향후에는 외상 후 스트레스 장애의 증상 정도뿐만 아니라 일상생활, 사회적 관계, 직업적, 사회적 적응 및 기능에 미치는 영향도 같이 평가하는 도구들이 개발되고, 현재 개발된 많은 평가 척도들이 새로이 수정되고 표준화되어, 이런 평가 척도들을 통해 외상 후 스트레스 장애의 경과와 외상 후 스트레스 장애로 인한 정신 사회적 영향을 더 잘 알 수 있는 자료들이 많이 수집되길 바란다. 대칭이, 작은대칭이, 펄조개는 저질이 니질인 곳에서 주로 서식하고 있었고 귀이빨대칭이는 사니질과 사질에 주로 서식하고 있었다. 특히 삽교호 수계 채집된 귀이빨대칭이는 사니질과 사질의 저질에서 출현하였다.및 내장낭 조직들이 중요한 에너지 저장소이며, 영양 공급 기관임을 알 수 있었으며, 폐각근 조직과 내장낭 조직들의 영양물질 함량 변화는 생식소의 에너지 요구에 따라 변하고 있음을 알 수 있었다.. 따른 신장 기능에 대한 영향을 평가해 보아야 한다.하를 조사한 결과, 연간 진동해역으로 유입되는 오염부하량은 부유물질 기준으로 전체 37,316 ton/yr로 추정되었고, 이중 육지기원 부하량이 9,809 ton/yr (26.3%) 였고, 해역의 침강량 23,576 ton/yr (63.2%), 양식생물의 배설량이 3,932 ton/yr (10.5%) 로 대부분이 해역의 침강량에 의한 것으로 조사되었다. 육지오염부하량이 변동이 없다는 전제 조건 아래, 진동만의 피조개 채묘장을 미더덕 양식장으로 품종전환시킬 경우, 전체 부하량은 산술적으로 약 196%가 증가한 72,998 ton/yr 가 되고, 양식생물의 배설량은 10배 정도 증가하게 되어 진동만의 오염부하를 가중하게 된다. 진동만은 여름철 빈산소수괴 및 적조가 빈번하게 발생하고 있으므로 미더덕 양식장을 새로이 시설할 경우 오염부하가 가중될 것으로 판단되어, 앞으로 진동만의 양식장 수용능력을 파악하여 적정량의 양식물량이 시설되어야 할 것이다.25 psu에서 가장 높게 나타났다.인 단백뇨는 진행성 경과의 위험성을 동시에 암시해 주는 매우 유용한 지표이다. 본 연구 결과 학교 신체 검사상에서 발견된 단독 단백뇨의 주된 원인은 기립성 단백뇨로 81.8%를 차지하였다. 그러나 지속성 단백뇨의 경우 비록 9.1%의 빈도를 보였지만, 신장 조직검사를 시행한 결과 진행성 경과를 취할 수 있는

• Transactions of the Korean hydrogen and new energy society
• /
• v.9 no.4
• /
• pp.169-176
• /
• 1998

An experimental study on effect of vapor-cooled heat stations in a 5.5 liter cryogenic vessel has been performed. The cryogenic vessel is made of stainless steel of thickness of 1mm and insulated by the combined insulation of vacuum, MLI(multi-layer insulation) and vapor-cooled radiation shield. Vapor-cooled heat stations are also constructed based on the 1-dimensional thermal analysis to reduce the heat inleak through a filling tube. Thermal analysis indicates that the vapor-cooled heat stations can substantially enhance the performance of vessel for cryogenic fluids with high $C_p/h_{fg}$ where $C_p$ the specific heat and $h_{fg}$ the heat of vaporization, such as $LH_2$ and LHe. The experimental results for $LN_2$ shows that the total heat inleak into inner vessel consists of 14% radiation and 86% conduction through the filling tube. Therefore, it is expected that the conduction heat in leak of the vessel for high $C_p/h_{fg}$ cryogenic fluids can be significantly reduced. powders. The amount of copper coating was 20wt%. In order to examine corrosion behavior of the electrodes, the corrosion current and the current density, in 6M KOH aqueous solution after removal of oxygen in the solution, were measured by potentiodynamic and cyclic voltamo methods. The results showed that Co in the alloy increased corrosion resistance of the electrode whereas Ni decreased the stability of the electrode during the charge-discharge cycles. The electrode used Si sealant as a binder showed a lower corrosion current density than the electrode used PTFE and the electrode used Cu-coated alloy powders showed the best corrosion resistance.

• Journal of the Korean Institute of Gas
• /
• v.19 no.6
• /
• pp.85-91
• /
• 2015

As the interest in hydrogen energy is being increased, it is a widely issue to develop a lot of hydrogen technologies in the field of production, storage, transportation, application and others. In the aftermath, there is a hydrogen town in Ul San, which is expected to expand application fields of hydrogen energy, as a demonstration project. The hydrogen town in Ul San can consist of high and low pressure part by the gas pressure. The high pressure part is managed by 'the high pressure gas safety control act'. And, low pressure part is managed by 'the guideline for the safety management of demonstration project of hydrogen town'. In this paper, to improve efficiency of safety management, the direction of safety management is reviewed by an analysis of low pressure hydrogen facility and safety management items. And then, some improvement directions are suggested. In the end, it is expected that the results of this study could help to activate construction of hydrogen town and improve efficiency of safety management as well.

• Composites Research
• /
• v.32 no.1
• /
• pp.78-84
• /
• 2019

This study focused on the prediction of the long-term performance of carbon fiber/epoxy composites using Dynamic Mechanical Analysis (DMA) and Time-Temperature Superposition (TTS). Single-frequency test, multi-frequency test, and creep TTS test were performed. A sinusoidal load of $20{\mu}m$ amplitude was applied while increasing the temperature from $-30^{\circ}C$ to $240^{\circ}C$ at $2^{\circ}C/min$ for the single-frequency test and the multi-frequency test. The frequencies applied to the multi-frequency test were 0.316, 1, 3.16, 10 and 31.6 Hz. In the creep TTS test, a stress of 15 MPa was applied for 10 minutes at every $10^{\circ}C$ from $-30^{\circ}C$ to $230^{\circ}C$. The glass transition temperature was determined by single-frequency test. The activation energy and the storage modulus curve for each temperature were obtained from glass transition temperature for each frequency by the multi-frequency test. The master curve for the reference temperature was obtained by applying the shift factor using the Arrhenius equation. Also, TTS test was used to obtain the creep compliance curves for each temperature and the master curve for the reference temperature by applying the shift factors using the manual shift technique. The master curve obtained through this process can be applied to predict the long-term performance of carbon fiber/epoxy composites for a given environmental condition.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.9 no.4
• /
• pp.243-252
• /
• 2006

Influence of the increasing carbon dioxide concentration in seawater on various marine organisms is assessed in this article with regard to the impacts of anthropogenic $CO_2$ introduced into surface or deep oceans. Recent proposals to sequester $CO_2$ in deep oceans arouse the concerns of adverse effects of increased $CO_2$ concentration on deep-sea organisms. Atmospheric introduction of $CO_2$ into the ocean can also acidify the surface water, thereby the population of some sensitive organisms including coral reefs, cocolithophorids and sea urchins will be reduced considerably in near future (e.g. in 2100 unless the increasing trend of $CO_2$ emission is actively regulated). We exposed bioluminescent bacteria and benthic amphipods to varying concentrations of $CO_2$ and also pH for a short period. The ${\sim}l.5$ unit decrease of pH adversely affected test organisms. However, amphipods were not influenced by decreasing pH when HCl was used for the seawater acidification. In this article, we reviewed the biological adverse effects of $CO_2$ on various marine organisms studied so for. Theses results will be useful to predict the potential risks of the increase of $CO_2$ concentrations in seawater due to the increase of atmospheric $CO_2$ emission and/or sequestration of $CO_2$ in deep oceans.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.20 no.1
• /
• pp.26-36
• /
• 2017

Korea is preparing an offshore carbon capture, transport and storage (CCS) demonstration project which is recognized as one of important $CO_2$ reduction technologies to mitigate climate change. The offshore CCS project aims to transport, inject and store large amount of $CO_2$ into offshore geologic formation, and has a potential risk of leakage which might cause disastrous damage to human health, environment and property. Therefore, in order to ensure the safety of the offshore CCS project, a strict HSE (health, safety and environment) management plan and its implementation are required throughout the project life cycle. However, there are no HSE domestic laws or regulations applicable to CCS projects, and the related research is insufficient in Korea. For the derivation of the essential and urgent requirement in HSE management framework applicable to the offshore CCS project in Korea, we analysed the HSE management methodologies and foreign CCS HSE management guidelines and cases. First, this paper has analyzed ISO 31000, a generalized risk management principles. Second, we have investigated the HSE management practices of CCS projects in Norway and UK. Based on the analyses, we suggested the necessity of developing the HSE Philosophy and the HSE management process through the whole life cycle. Application of HSE management in early phase of an offshore CCS project will promote systematic and successful project implementation in a cost-effective and safe way.

• The Korean Journal of Nuclear Medicine
• /
• v.35 no.1
• /
• pp.33-42
• /
• 2001

Purpose: The purpose of this study was to evaluate the effect of scatter correction on the assessment of myocardial perfusion and left ventricular function by gated Tc-99m myocardial SPECT. Materials and Methods: Subjects were 11 normal volunteers, 20 patients with non-cardiac chest pain and 13 patients with coronary artery diseases. We classified above 3 groups into normal and diseased groups. Scatter correction was done using dual-energy-window scatter correction method (DEW-SC). We compared acquired counts, image contrast, corrected maximum relative counts, indices of left ventricular function, extent and severity of perfusion defects calculated by 'CEqual program' between scatter non-corrected and corrected images. Results: Scatter corrected studios was lower in counts by $18{\pm}3%$ than uncorrected studies, but image contrast were improved in all cases. Scatter correction using DEW-SC took 3 minutes to complete, and 512 kB memory to store. There were no significant differences among indices of left ventricular function between scatter non-corrected and corrected images. Although extents of perfusion defects were not significantly different, severity was severer in scatter corrected images. Conclusion: Scatter correction using DEW-SC is simple to do, and improves image contrast without changing other indices of myocardial perfusion and function.