• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2020.06a
• /
• pp.140-141
• /
• 2020

Concrete has a lower thermal conductivity or thermal diffusion coefficient compared to other building materials, so it is widely used as fireproof compartment material or refractory material for structures. However, in the event of thermal damage such as fire, cement curing agents and aggregates act differently, resulting in heat generation or deterioration of tissue due to dehydration, resulting in deterioration of physical properties and fire resistance. Therefore, in this study, the processing structure of cement paste is measured through nitrogen absorption method. The test specimen is a cement paste of 40% W/C and is set at 1000 ℃ under heating temperature conditions. As the temperature rose, the micro-pore mass below was reduced based on about 0.01 감소m, but the air gap above that was increased.Thus, in the range of pores measured in nitrogen adsorption, the air mass tended to decrease under high temperature conditions.

• Journal of the Korean Chemical Society
• /
• v.14 no.1
• /
• pp.97-107
• /
• 1970

The grand canonical ensemble partition function for the adsorbed phase of gases on solid surfaces is derived according to the transient state theory of significant liquid structure. The derived adsorption isotherms from the partition function for argon, nitrogen and benzene adsorbed on various adsorbents are in good agreement with the observed values. The surface pressure, the molar entropy, the molar internal energy and the molar heat of adsorption are calculated for benzene adsorbed on graphite. The molar entropy is minimum at near the pressure where a close packed monolayer is formed. The method of parameter determination is illustrated.

• Journal of Wetlands Research
• /
• v.13 no.3
• /
• pp.465-470
• /
• 2011

Liquid fertilizer and composted cattle manure were applied to an agricultural land. This study was conducted to find the pathway of the nutrients transport. Nitrogen concentration was decreased by the repeatable precipitation in surface runoff, but the nitrate concentration in ground water was gradually increased by biological metabolism, especially with pig liquid fertilizer. Phosphorus was mostly adsorbed into the soil, and its reduction was affected by the soil drain by surface runoff in the summer. Averaged adsorption capacity of the phosphorus via Jar-test was determined as 21.5 mg P/kg of soil.

• Proceedings of the Korean Society of Environment and Ecology Conference
• /
• 2009.10a
• /
• pp.276-279
• /
• 2009

• 한국전기화학회:학술대회논문집
• /
• 2004.04a
• /
• pp.75-75
• /
• 2004

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 1998.04a
• /
• pp.168-170
• /
• 1998

• Journal of the Korean Chemical Society
• /
• v.38 no.1
• /
• pp.26-33
• /
• 1994

Adsorption isotherms of nitrogen and argon on various adsorbents measured up to present by authors are used to make the V-t plots using various numerical and the analytical standard adsorption isotherms to estimate the appropriateness of these standard isotherms. It is confirmed that the analytical FHH equation is appropriate for wide range of adsorbents as a standard isotherm.

• Proceedings of the Korean Institute of Industrial Safety Conference
• /
• 2003.10a
• /
• pp.160-163
• /
• 2003

산업시설의 급속한 팽창과 더불어 날로 증가하는 환경오염 문제는 대기 배출오염원과 그 종류가 다양해지고 있어 점차 인체에 유해한 대기 오염이 중요한 사회적 문제가 되고 있다. 오염물질 중 암모니아를 포함한 유해 가스는 화학공정에서 뿐만 아니라 양돈양계장, 비료공장, 사료제조공장, 분뇨처리장 등으로 그 발생원이 다양하며 질소를 함유한 유기물이 생물학적으로 분해될 때 생성된다.(중략)

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2000.04a
• /
• pp.337-339
• /
• 2000

저준위 환경 방사능 측정에서 가장 문제가 되는 것은 주변의 백그라운드에 의한 영향이다. 백그라운드로는 우주선, 지각 방사선, 그리고 대기중의 방사선 둥이 있다. 이러한 백그라운드를 감소시킬 수 있다면 저준위 방사능 측정의 감도향상은 물론 정확성을 향상시킬 수 있다. 이러한 백그라운드 중에서 대기중의 방사선은 주로 지각으로부터의 라돈 방출에 의하여 기인하게 된다(Eisenbud, 1987 : Thomas, 1972). 방출된 라돈 및 딸핵종들은 대기 중의 먼지에 흡착되어 부유하게 되는데, 부유 먼지에 흡착된 백그라운드의 주요 원인이 된다. (중략)

• Applied Chemistry for Engineering
• /
• v.9 no.6
• /
• pp.798-802
• /
• 1998

Carbon granules were prepared by granulating a mixture of coconut shell powder and coal tar solution, and then by carbonizing at different temperatures. To control micropores of the carbonized granules, the deposition time of benzene vapor under nitrogen atmosphere was varied. For each prepared sample, SEM morphology and true density were investigated. The adsorption rates on the granules were measured with respect to oxygen and nitrogen by means of the Cahn D-200 system. Diffusivity, selectivity and amount of equilibrium adsorption for the gases were obtained from the measurement of adsorption rate. Based on the analysis of the adsorption characteristics, the optimum temperature and the deposition time for preparation of the molecular sieve carbon granules were found to be $800^{\circ}C$ and 10 minutes, respectively. At these optimal conditions, the selectivity coefficient, 26.4, 0f oxygen and nitrogen was obtained.