• Journal of the Optical Society of Korea
• /
• 제17권6호
• /
• pp.548-558
• /
• 2013

In this work, laser induced breakdown spectroscopy (LIBS) is used to investigate soil samples collected from different desert areas of Riyadh city in Saudi Arabia. Both qualitative analysis and plasma parameters are studied via the observed LIBS spectra. These experiments have been done using a Spectrolaser-7000 system with 50 mJ fundamental wavelength of Nd:YAG laser and detection delay time of 1 microsecond. Many spectral lines are highly resolved for many elements like Al, Fe, Mg, Si, Mn, Na, Ca and K. The electron temperatures Te and electron densities Ne, for the constituent of generated LIBS plasma, are determined for all the collected samples. It is found that both Te and Ne vary from one desert area to other. This variation is due to the change of the elemental concentration in different desert areas that affects the sample's matrices. Time dependent measurements have also been performed on the soil samples. While the signal-to-base ratio (SBR) reached its optimal value at 1 microsecond, the plasma parameters Ne and Te reach values of $4{\times}10^{17}cm^{-3}$ and 9235 K, respectively, at 2.5 microsecond. The later indicate that the plasma cooling processes are slow in comparison to the previously observed results for metallic samples. The observed results show also that in the future it is possible to enhance the exploitation of LIBS in the remote on-line environmental monitoring application, by following up only the values of Ne and Te for one element of the soil desert sample using an optical fiber probe.

• 대한설비공학회:학술대회논문집
• /
• 대한설비공학회 2008년도 하계학술발표대회 논문집
• /
• pp.869-872
• /
• 2008

On this study, the Control of Temperature is specified on the view of indoor comfort and building energy consumption. It is estimated by Dynamic heat load simulation which has the factors of insulation method and the soil thickness of the green roof system. The fact that the model which has no insulation has the greatest effect of dropping high temperature and the cooling load decrease is confirmed.

• 설비공학논문집
• /
• 제21권6호
• /
• pp.355-366
• /
• 2009

In the present study, fuel cell driven ground source heat pump system is applied to a large community building and performance of the heat pump system is computationally analyzed. Conduction heat transfer between brine pipe and ground is analyzed by TEACH code to predict the performance of heat pump system. Predicted COP of the heat pump system and the energy cost were compared with variation of the location of the objective building the water saturation rate of soil and the driven powers of heat pump system. Significant reduction of energy cost can be accomplished by employing the fuel cell driven heat pump system in comparison with the late-night electricity driven system. It is due to the low electricity production cost of fuel cell system and the application of recovered waste heat generated during electricity production process to the heating of large community building.

• KIEAE Journal
• /
• 제12권4호
• /
• pp.41-46
• /
• 2012

In Korea, Apartment houses recently occupy over 80% of all buildings. Ground source system has to be designed to consider feature of apartment house. Most apartment houses use PHC pile to get a bearing power of the soil. Therefore, the purpose of this study is to evaluate performance of ground source heat pump system utilizing energy pile under apartment. Object of experiment is low-energy experiment apartment in Song-do and Energy Pile are applied to 80%, 100% energy reduction model for heat-source. First, performance evaluation of Energy Pile geothermal system was done during summer season. As a result, The COP(coefficient of performance) about geothermal heatpump was approximately 5-6 while cooling. In winter season, Long experiment was performed because it was very important to evaluate ground condition for long time. During heating experiment, Indoor room set temperature was $20^{\circ}C$ and kept constant by heating. Coefficient of performance for heat pump and overall system was calculated. It was 3.5-4.5 for COP and 2.5-3.7 for system COP.

• KIEAE Journal
• /
• 제4권2호
• /
• pp.65-72
• /
• 2004

Ecological architecture enables people to recycle and reuse architectural resources within the category of ecosystem and also to minimize the effect on environment in a whole process, including architectural planning, usage and exhaustion to use sustainable energies. Rammed earth wall construction method utilized in EcoCenter located in Crystalwaters ecological village in Austrailia is a good example, which maximizes its advantages and also covers its limits to use soil and wood as structural resources. In a case of wood, they used non-treated timber to minimize environmental load and utilized used materials in openings. In the roofs, aluminum coated steel which is plated with zinc collects rain effectively even though it is not regenerable. Nontoxic finishes and insulation in floor and ceiling with used papers are able to minimize its environmental load. Solar energy system applied in EcoCenter enables them to market extra energy with electricity companies as well as support needs of its own buildings to utilize photovoltaic panel system with PV panels. Passive solar system is planned effectively in heating and cooling to apply regenerative walls in a use of rammed earth wall construction and natural ventilation systems through openings.

• 한국지반공학회논문집
• /
• 제33권3호
• /
• pp.37-47
• /
• 2017

극한지에 구조물을 안정적으로 건설하기 위해서는 동결토의 지반공학적 특성을 평가하는 것이 중요하다. 본 연구에서는 남극 제2과학기지(장보고 기지)가 건설된 남극 테라노바만 인근지역의 현장시료를 이용하여 동결토와 비동결토의 동적특성(전단탄성계수, 감쇠비)을 Stokoe 식 공진주 실험기를 이용하여 평가하였다. 시편을 동결시키기 위해 시편의 온도제어가 가능하도록 공진주 실험시스템을 개선하였으며, 다양한 밀도로 조성된 시편에 대해 동결상태와 비동결상태에서 공진주 실험을 수행하였다. 동결토 실험에서는 $-7^{\circ}C$에서 얼린 시료를 이용해 전단변형률에 따른 전단탄성계수와 감쇠비를 획득하였고, 이를 비동결토의 특성과 비교하였다. 또한, 동결토의 온도변화에 따른 최대전단탄성계수와 감쇠비 변화를 실험적으로 평가하여 동결-융해 작용에 의한 지반의 역학적 특성 변화를 확인하였다. 본 연구를 통해 동결토와 비동결토의 동적특성 차이를 확인하였으며, 온도상승이 동결토에 미치는 영향을 확인했다는 점에서 공학적 의의가 있다.

• 설비공학논문집
• /
• 제25권8호
• /
• pp.427-431
• /
• 2013

Ground heat pump systems utilize the annually stable underground temperature to supply heat for space heating and cooling. The underground temperature affects not only the underground ecosystem, but also the performance of these systems. However, in spite of the widespread use of these systems, there have been few researches on the effect of the systems on underground temperature. In this research, case studies with numerical simulation have been conducted, in order to estimate the effect of ground heat pump systems on underground temperature. The simulation was coupled with the ground water-ground heat transfer model and the ground surface heat transfer model. In the result, it was found that the underground change depends on the heat transfer from the ground surface, the heat exchange rate, and the heat conductivity of soil.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2003년도 추계학술대회 논문집
• /
• pp.333-335
• /
• 2003

Deep Ocean Water is formed within restricted area including polar sea (high latitude) by cooling of surface seawater and globally circulated in the state of insolation with surface seawater. Although not as obvious as estuaries mixing, Brine groundwater is mixture of recirculated seawater and groundwater. Seawater having high osmotic pressure infiltrate into unconfined aquifer where is connected to the sea. The ions dissolved in seawater are present in constant proportions to each other and to the total salt content of seawater. However deviation in ion proportions have been observed in some brine groundwater. Some causes of these exception to the Rule of constant proportions are due to many chemical reactions between periphery soil and groundwater. While Deep Ocean Water (DOW) have a large quantity of functional trace metals and biological affinity relative to brine groundwater, DOW have relatively small amount of harmful bacteria and artificial pollutants.

• 농업과학연구
• /
• 제26권2호
• /
• pp.70-76
• /
• 1999

Rice farming is not only the most important income resources of Korean farmers but also the roots of Korean traditional culture. Paddy fields have acted as an food supply base but also have contributed to the public multi-functions such as flood control, water conservation, controlling soil erosion, providing recreational and resting spaces, water purification, air cleaning, oxygen supply and air cooling and so on. The public multi-functions of paddy except rice production have not been evaluated before UR negotiation and starting WTO system. Under the drastic changes of rice economic settings as price decrease of rice and downward decrease of farm income, Korean and Japanese farmers might have lost their intention to grow rice in paddy fields without the direct payment system to compensate rice income decrease. To adapt the direct payment system, the total public value of multi-function of paddy should be identified in terms of money. According to the research results, the total value of multi-functional value of paddy in Korea were estimated 21,596thousand won which is higher than rice production value by 2.1 times. On the other hand the total value of Japanese paddy were amounted to 21,390 Yen which is more than that of Korea by 10times outstandingly. Likewise Japanese have evaluated the paddy field very important enterprise from the view point of food security and multi -functions of paddy to their socio-economic life and environmental sustainability in Japan.

• 자원환경지질
• /
• 제38권6호
• /
• pp.717-729
• /
• 2005

일반적으로 대규모 건물의 피크 냉방 부하는 난방부하보다 크다. 북위도의 한냉한 지역에 소재한 대규모건물의 냉난방 설비는 건물 내부에서 생성되는 발열량과 태양으로부터 획득되는 열량에 따라 좌우된다. 최대 냉방부하에 적합하도록 냉난방설비와 지중루프를 설치하는데 소요되는 비용은 일반적으로 초기투자비가 적게 드는 전통적인 HVAC시스템에 비해 다소 고가이다. 빙축열조(Thermal ice storage, TES)시스템은 과거 수년동안 일반 HVAC에서 냉동기의 용량을 축소시키거나 최대 전력부하 시간대를 바꾸기 위해 사용되어온 기술이다. 일반적으로 건물 난방을 위해서는 보일러와 같은 전통적인 난방설비를 이용하고 그 다음날의 건물냉방을 위해서는 전력료가 저렴한 야간에 빙축을 시키는 빙축열기법을 이용한다. 얼음에서 추출한 잠열 에너지의 장점을 이용하기 위해 설계된 분배시스템(distribution system)과 열원과 열배출원(열침, sink)대신에 지중열 교환기(지중루프)를 이용하면 많은 장점이 있다. 공간 난방과 급탕을 공급하기위한 분리형 설비를 별도로 사용하지 않아도 된다. 공간난방용으로 소요되는 설비용량을 축소시킬 수 있으며-소요 지중열 교환기의 규격과 비용을 절감시킴은 물론 지열 HVAC시스템의 효율을 배가 시킬 수 있으며 온실가스 배출량을 대폭 감축시킬 수 있다. 또한 TES를 적용하면 대규모 건물의 냉난방부하와 열펌프의 용량을 $40\~60\%$ 정도 감축시킬 수 있으며 설비대수와 기계실 공간을 줄일 수 있다. 뿐만아니라 피크 냉난방부하를 토대로 설계한 지원 열펌프 시스템(Ground source heat pump system)의 지중루프를 $1/4\~1/3$가지 줄일 수 있어 도심지역에서 지중루프를 설치할 때 장애요인인 지중루프 설치공간문제와 지중암석의 열적특성문제를 동시에 해결할 수 있다.문이며, 따라서 $^{137}Cs$의 분포는 광물분포 보다는 TOC의 함량에 더 큰 영향을 받고 있음을 보여준다.과 위기 고조 단계, 그리고 갈등 해소 단계등 모든 시기에서 두 신문의 주요 행위자 구성에 있어서 차이가 나타났다. 다시 말해, 조선일보는 기본적으로 총파업을 둘러싼 문제의 구성과 발전, 해소 과정에서 정당이나 대통령, 야당 지도자 등과 같은 정치관련 행위자를 강조하고 있었다. 반면에, 한겨레는 대체로 로든 사건진행 단계에서 노동 관련 단체들과 시민단체의 역동적인 연대와 활동에 초점을 맞추고 있는 것으로 나타났다.술 후 24시간에 599.4$\pm$145.6, 678.8 $\pm$256.4였다(t-test, p < 0.05). 동종 수혈은 RAP군에서 34명 중 7명에서(20.6$\%$), 대조군에서는 46명중 16명에서(34.8$\%$) 시행되어, RAP군에서 유의하게 빈도가 낮았다(Chi-square test, p < 0.05). 결론: 역행성 자가 충전법은 심폐바이패스의 충전에 의한 혈액희석을 최소화함으로서, 개심술 후 출혈과 동종수혈을 또한 줄이는 데 효과적인 방법이 될 수 있다고 생각된다.타내지 않았다.성 교사, 가정 전공 교사가 그렇지 않은 교사보다 해석적, 해방적 행동목표를 더 중요하게 인식하고 있었다. 특히 가정교육 철학을 배운 경험이 있는 교사가 그렇지 않은 교사보다 해방적 행동체계 목표를 중요시하는 것으로 나타났다. 이 연구 결과는, 실천 비판적인 가정 교과의 본질을 구현하기 위해서는 주생활 영역의 교육과정에 기술적, 해석적, 해방적 행동에 대한 목표들을 고루 포함하여야 하며 특히 교사들이 중요하게 인식하는 해방적 행동에 대한 목표를 강조하여 적용할 필요가 있음을 시사하고 있다.교하여 유의한 차이가 관찰되지 않았다. 또한