• Journal of The Korean Astronomical Society
• /
• v.29 no.spc1
• /
• pp.45-48
• /
• 1996

Rings are common in disk galaxies. These rings are either indistinguishable from a pair of tightly wound spirals, or themselves are a part of the spiral structure. Furthermore, their occurrence is seen coincident with a bar in the center. In this paper, we interpret this spiral-ring structure as density waves resonantly excited by a rotating bar potential. The theory gives excellent agreement for the molecular spiral-rings in central parts. of nearby disk galaxies, observed by high resolution radio arrays. The same mechanism works for more distant spiral-rings in the outer parts of disk galaxies qualitatively, although the problem is complicated by the coupling of the stellar and gaseous disks.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.1302-1306
• /
• 2007

Malfunction or inappropriate management of ventilation system in public transportation may cause unpleasant atmosphere or health problems to the old or feeble passengers. In this work, adsorption/desorption system for gaseous carbon dioxide is developed and tested under the various indoor conditions. Finally an optimum design specification for the indoor $CO_2$ control will presented.

• Asian-Australasian Journal of Animal Sciences
• /
• v.12 no.2
• /
• pp.295-304
• /
• 1999

The planning and application of new developments in management of wastes. in hog farming is required to minimise the gaseous emissions from wastes and pollution of the aquatic environment. These strategies are enveloped in the "Farm Waste Management Plan" which identifies areas of the waste assets in form of plant nutrient and considers optimal manute collecting and storing procedures. The storage volumes for environmentally acceptable manure treatments and application methods are suggested. Good Waste Management Planning together with appropriate system design will ensure safe, reliable and effective waste handling.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2003.11a
• /
• pp.247-248
• /
• 2003

Tunable diode laser absorption spectroscopy (TDLAS) has been widely used in environmental monitoring of gaseous species in the past decade. TDLAS is a direct measurement technique for pollutants such as NOx without any interference from other species. Because of its superior spectral purity (～0.001 ­$cm^{-1}$), absorption linewidths with resolvable rotational structure can be studied in the mid infrared region where strong fundamental vibrational transitions of molecules appear. (omitted)

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2003.11a
• /
• pp.364-365
• /
• 2003

최근 대기기인 오염물질이 환경계에 미치는 영향에 대한 관심이 높아짐에 따라 호소수질에 직ㆍ간접적으로 영향을 주는 대기오염물질에 대한 관심이 커지고 있다. 특히 호소에 유입되는 영양염류 중 질소화합물에 대한 기여수준을 평가한 최근자료에 의하면 대규모 호소 중 89％에 상당하는 호소수내의 질소성분이 자연적으로 존재하는 양을 초과하고 있는 것으로 판단하고 있으며, 초과된 질소성분 중 최고 38％가 대기오염물질과 관련된 질소성분인 것으로 보고하고 있다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2000.11a
• /
• pp.413-414
• /
• 2000

Dibble과 Raupp에 의하여 TiO$_2$와 UV를 이용한 기상 TCE 분해 연구가 수행된 이후 대기오염정화를 위해 TiO$_2$/UV 시스템의 다양한 연구가 집중되어 오고 있는데 (Alberici, 1997), 휘발성유기화합물과 악취성분들의 제거가 주요 목적이 되고 있다. 아세트알데히드는 자극적인 과일 썩는 냄새가 나는 대표적 악취 물질임과 동시에 높은 증기압(740mmHg @2$0^{\circ}C$)으로 휘발성유기화합물로 규제되고 있으며, 요즘현대인들에게 "Sick Building Syndrome"이라는 사회적 문제를 일으키는 물질이다(T. Noguche. 1998). (중략)

• Journal of Korean Society for Atmospheric Environment
• /
• v.11 no.2
• /
• pp.118-129
• /
• 1995

일반폐기물의 효과적인 처리방법으로 소각처리가 중요시되고 있으나 폐기물의 소각과정에서 대기오염물질이 발생, 배출되게 되므로 이에 대한 적절한 대책이 필요하다. 배출되는 대기오염물질의 종류 및 양은 소각하는 폐기물의 성상이나 폐기물 소각로의 형태, 소각로의 운전 조건에 따라 달라질 수 있으나 주요 오염물질로는 최근 문제시되고 있는 Dioxin이나 광화학스모그를 유발시키는 질소산화물(이하 NOx), 염화수소 등을 들 수 있다. 이러한 오여물질에 대한 환경오염을 방지하기 위해서는 적절한 배출억제대책이 필요하다. 본고에서는 폐기물의 소각시 배출되는 대표적인 오염물질의 특성과 그 배출억제 방법에 대해 기술하고자 한다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2000.11a
• /
• pp.266-269
• /
• 2000

To understand the gaseous behaviour of volatile organic compounds in the unsaturated zone, their volatilization coefficient k$_{Lg}$ is evaluated. An experiment is conducted to examine the dependence of k$_{Lg}$ on the concentration of the dissolution, presence of unsaturated zone and depth of the unsaturated zone. The results show that the volatilization coefficient is not dependent on the concentration under the constant temperature and pressure. It is also find that k$_{Lg}$ depends on the presence of the unsaturated zone rather than its depth.depth.

• Analytical Science and Technology
• /
• v.8 no.4
• /
• pp.477-480
• /
• 1995

Isotopic-spectral method [I] was applicated for determination of carbon in silicate materials (pure silica, guartz glasses, geological probs etc.). Isotopic heterogeneous balancing of carbon in gaseous phase and solid samples was carried out at the temperature of $1500-1900^{\circ}K$. Spectroscopic measuring of isotope concentration in a balanced gas was made using the electron-vibrational band heads of CO molecules excited in HF discharge. Limits of detection of carbon concentrations appear to be $n^*10^{-6}$.

• Journal of Plant Biology
• /
• v.14 no.3
• /
• pp.43-46
• /
• 1971

Losses of nitrogenin the gaseous form were determined with closed systems in the filed under different vegetation types. Ammonia volatilization was greatest from the pine stand, and least from the sod stand, and was greatly reduced in all three sites in the rainy season due to the low temperature. There were only insignificant differences in the nitrogen dioxide volatilization from the soil of the three vegetation types. Losses of ammonia and nitrogen dioxide at various soil depth also showed little variation. Evidently the microbial activity responsible for the $NO_2$ loss was relatively unaffected by the changes in temperature and soil moisture content during the investigation.