• 천문학회보
• /
• 제46권2호
• /
• pp.64.1-64.1
• /
• 2021

Accretion flows around black holes and neutron stars emit high energy radiation with varying spectral and timing properties. Observed timing variations, both short and long-term, point to the existence of a mechanism, dictated by the flow dynamics, and not by the stellar surface or magnetic fields, that is common in both. Spectral energy distributions of multiple sources indicate that the Comptonization process, the dominant mechanism for changing states in X-ray, takes place inside the flow that has similar physical properties in both the objects. In a series of observational and numerical studies, we enquire about the following: 1. Is there a steady state configuration for accreting matter around black holes that can explain spectral and timing properties? 2. Could a similar formalism explain spectral and timing properties of accretion around neutron stars? 3. Could there be a generalized flow configuration for accreting matter around such compact objects? Furthermore, we show that a unified spectral model can be constructed based on the generalized flow configuration, common to black holes and neutron stars.

• 대한건축학회논문집:계획계
• /
• 제34권1호
• /
• pp.33-40
• /
• 2018

The society for conservation of local historical properties in Korea originated in Japan. It was transplanted by Joseon Governor-General to represent their positions in the field of the conservations of the cultural properties. Also the society for conservation of local historic properties represented the positions of the provincial government office because the representatives of that societies were the chief of local government offices. At that time, the fundamental concept of the historical property conservations was not settled, so they accomplished the conservation activities as the necessary way for themselves.They often made a proposal about repairs for conservation of historical building and suggested a application for the national budget. And they contributed to carry out the repair works of the historical properties in the early Japanese colonial period. But they was usually used to invigorate the tourism and to publicize the regional characteristics through the historical properties. Although the societies were privately-managed as a matter of form, they were governmentally-managed as a matter of fact. It was the limits of the societies for conservation of local historical properties at that time.

• 한국자기학회지
• /
• 제5권5호
• /
• pp.716-719
• /
• 1995

Pd/(Pt/Co/Pt) modulated multilayer films have been deposited on various substrates with Pd/Pt buffer layers. Films grown at different temperatures have very distinct magnetic properties and surface microstructures. Atomic force(AFM) and scanning tunneling (STM) microscopies studies of these films reveal that films deposited at room temperature have small grain structures with an average grain size of about $140\;{\AA}$. However, much larger grains of about $1200\;{\AA}$ in size are observed in the films grown on buffer layers which were deposited at $500^{\circ}C$. These large grains are found to actually consist of smaller grains of about $170{\AA}$ in diameter. SQUID magnetic and Kerr hysteresis loop measurements indicate that multilayer films with large grains exhibit high magnetic coercivities of around 5 kOe. A subgrain growth model is proposed to understand the observed grain structures in the multilayers.

• 한국실내디자인학회논문집
• /
• 제23권1호
• /
• pp.3-13
• /
• 2014

After The Industrial Revolution in 18th century, constructions were done with universal material (concrete) in everywhere instead of using materials that are produced in each country because of development of industry material and transportation. This change caused the buildings to become trite with no local characteristics. Hereupon, the study intends to understand the essence of matter and restore various construction methods of each matter with the topic of 'Immateriality'. Immateriality is the revealed concept based on Materiality. Consequently the process and characteristics of immateriality shown on the works of Kuma Kengo and Herzog & de Meuron, three kinds of features can be found of immateriality expression mode. They are as in the following. First, there is a mode of transforming the shape and properties in physical or psychological way by observer. Second, there is a mode of conflating the shape and properties in physical or psychological way by observer. Third, there is a mode of mixing the shape and properties in physical or psychological way by observer.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제17권6호
• /
• pp.59-68
• /
• 2012

This study provided sorption properties of chlorofluorocarbons (CFCs), and elucidated potential application of CFC sorption data in hydrogeochemistry. Prior sorption studies were reviewed for hydrophobic organic compounds similar to the CFCs, because there were only few CFC sorption studies. The CFCs are regarded as relatively conservative chemicals in groundwater environments based on their moderate hydrophobicity. However, thermally altered carbonaceous matter (TACM) can significantly increase sorption capacity and nonlinearity for hydrophobic organic compounds such as CFCs, compared to general soil organic matter. CFC sorption behavior are close to the sorption for reviewed organic chemicals. Therefore, the CFC sorption data can be used for determining hydrogeochemical properties and predicting transport of organic contaminants in TACM-containing aquifer environments.

• Environmental Engineering Research
• /
• 제18권3호
• /
• pp.151-156
• /
• 2013

Several soil properties were studied from three young created mitigation wetlands (<10 years old), which were hydrologically comparable in the Piedmont region of Virginia. The properties included soil organic matter (SOM), soil organic carbon (SOC), pH, gravimetric soil moisture, and bulk density ($D_b$). No significant differences were found in the soil properties between the wetlands, except SOM and SOC. SOM and SOC indicated a slight increase with wetland age; the increase was more evident with SOC. Only about a half of SOC variability found in the wetlands was explained by SOM ($R^2$ = 0.499, p < 0.05). The majority of the ratios of SOM to SOC for these silt-loam soils ranged from 2.0 to 3.5, which was higher than the 1.724 Van Bemmelen factor, commonly applied for the conversion of SOM into SOC in estimating the carbon storage or accumulation capacity of wetlands. The results may caution the use of the conversion factor, which may lead to an overestimation of carbon sequestration potentials of newly created wetlands. SOC, but not SOM, was also correlated to $D_b$, which indicates soil compaction typical of most created wetlands that might limit vegetation growth and biomass production, eventually affecting carbon accumulation in the created wetlands.

• 한국식품영양과학회지
• /
• 제25권5호
• /
• pp.810-816
• /
• 1996

침지온도 $20^{\circ}C$에서 침지 후 30분에서 35분 사이에 대부분의 품종이 평형에 도달했으며, 평형수분 함량은 0.3247~0.3577(g $H_2O/g$ dry matter)로 나타났다. 초기 수분흡수 속도에서는 품종간에 차이를 나타내었으며, 특히 낙동벼의 경우 0.123g $H_2O$/$min^{1/2}$로 가장 높은 값을 나타냈다. 취반 후 밥의 수분 함량은 가수율에 따라 증가하였으며, 가수율이 1.3에서 1.6(v/w)으로 증가함에 따라서 밥의 수분 함량은 품종에 따라 약 6.0~7.0%증가하였다 가수율에 따른 취반 후 밥의 경도는 가수율이 증가할수록 감소하는 경향이었으며 끈기와 끈기대 경도의 비는 대체적으로 증가하였다.

• 한국토양환경학회지
• /
• 제3권2호
• /
• pp.31-39
• /
• 1998

오염지역과 비오염지역으로부터 채집한 토양에서 토양의 습도, 유기물의 함량, 토양산도 등 물리적인 특징과 토양미생물의 분포와 같은 생물학적인 특징이 조사되었다. 지역에 따른 유기물의 함량과 토양산도는 큰 차이를 나타내었으나, 식물군락에 의한 토양수분과 유기물 함량의 차이점은 발견할 수 없었다. 토양의 산도는 미생물의 분포수와 상관관계를 나타내었다. 이러한 것은 식물이 자라는 토양에 변이를 주는 것으로 산성비와 관련이 있는 것으로 추정된다.

• Elastomers and Composites
• /
• 제56권4호
• /
• pp.243-249
• /
• 2021

The demand for truck bus radial (TBR) tires with enhanced fuel efficiency and wear resistance have grown in recent years. In addition, as the issue of particulate matter and air pollution increases, efforts are being made to reduce the generation of particulate matter. In this study, we investigated the effect of varying the content of butadiene rubber (BR) on the properties of the rubber compounds and the amount of particulate matter in the TBR tire tread compound. Furthermore, we utilized carbon black in the NR/BR blend compounds owing to its excellent compatibility, and we used silica in the ENR-25/BR blend compounds because it can interact chemically with epoxide groups. The NR/BR blend compounds and the ENR-25/BR blend compounds were evaluated by varying their BR content between 20 phr and 30 phr. The results showed that the ENR-25/BR blend compounds had superior wear resistance than the NR/BR blend compounds. This was caused by the interaction between silica and ENR. In addition, it was confirmed that the increased wear resistance as the BR content increased. Furthermore, compared to the NR/BR blend compounds, ENR-25/BR blend compounds exhibited a lower tan 𝛿 value at 60℃ because silica was used as filler. This indicates a higher fuel efficiency. The measurement results for wear particulate matter showed that as increasing the BR content resulted in generation of less wear particulate matter. This was caused by the increased wear resistance. Moreover, the ENR-25/BR blend compounds with excellent filler-rubber interaction exhibited lower quantities of generated wear particulate matters as compared to the NR/BR blend compounds.

• 한국수처리학회지
• /
• 제26권6호
• /
• pp.43-51
• /
• 2018

In order to systematically and scientifically manage the organic and heavy metals against sediment at Daecheon Port, this study conducted particle composition, organic materials and heavy metals irradiation studies of sediments. Analysis of the grain size composition of sediments in the target study area showed the distribution characteristics of the mix of sand, silt and clay. That is, Station C (Stn. C) showed superior by fine-grained sediment, Station A and B (Stn. A and B) showed superior by coarse-grained sediment. The organic matter(COD, TOC, and IL) of Stn. C was appeared to be heavily polluted more than Stn. A and B. These data for the spatial properties in sediment showed that organic matter was related positively to the sediment silt-clay content. Also, in the case of heavy metals contamination in surface sediments, Stn. C was higher than Stn. A and B. Particularly, at the Stn. C, high organic matter concentration and C/N ratio value( >10) indicated that the sediment was composed highly of land-derived organic matter. From these results, it considered that the correlation analysis among to silt-clay, organic matter and heavy metal was found to have a good interrelationship.