• 건축역사연구
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• 제16권4호
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• pp.7-22
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• 2007

In San Francisco, two new museums were recently built in 1995 and 2005. The one is San Francisco Museum of Modern Art designed by Mario Botta and the other is De Young Museum designed by Jacques Herzog & Pierre de Meuron. The urban settings for the museums are compared with each other and theories of the architects are evolved on different branches in the modernist trends. The theories and settings are followed by the representation in the forms, facades, interior spaces and towers. SFMOMA is located on the SoMa area, which was recently developed into a cultural urban core with Moscone Center and Buena Yerba Garden. De Young Museum was rebuilt in the old museum site in the Golden Gate Park. The one is on the context of urban artefacts and the other on the context of natural artefacts. To Botta, the museum in today's city plays a role analogous to that of the cathedral of yesterday. It is a place of common encounter and confrontation. The volume of SFMOMA which is geometrical and symmetric with double pylons. The frontality on the street and public green open space and the axiality of SFMOMA runs through the Buena Yerba Garden over Buena Yerba Center for the Arts are reminded us of an urban core with a religious monument and a city square. The staircase with grandiose design in the atrium seems to work as an altar with lighting from skylight above enhancing the liturgical ambiance. De Young Museum is shaped in a rectangle with long narrow courtyards. Three bands of volumes are juxtaposed and the nature flows into the museum corridors and galleries. The tower is distorted so as to be aligned to the street grids of the surrounding area. The copper panel of De Young Museum and natural context evoke modern concept of "machine in the garden". The two museums from different pedigrees of Modern Architecture are now major landmarks of SF and urban expressions for the 21st century.

• Architectural research
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• 제18권2호
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• pp.59-64
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• 2016

Since the massive power outages that hit across the nation in September 2011, a growing imbalance between energy supply and demand has led to a severe backup power shortage. To overcome the energy crisis which is annually repeated, a policy change for deriving energy supply from renewable energy sources and a demand reduction strategy has become essential. Buildings account for 18% of total energy consumption and have great potential for energy efficiency improvements; it is an area considered to be a highly effective target for reducing energy demand by improving buildings' energy efficiency. In this regard, retrofitting buildings to promoting environmental conservation and energy reduction through the reuse of existing buildings can be very effective and essential for reducing maintenance costs and increasing economic output through energy savings. In this study, we compared the energy reduction efficiency of national power energy consumption by unit production volume based on thermal power generation, renewable energy power generation, and initial and operating costs for a building retrofit. The unit production was found to be 13,181GWh/trillion won for bituminous coal-fired power generation, and 5,395GWh/trillion won for LNG power generation, implying that LNG power generation seemed to be disadvantageous in terms of unit production compared to bituminous coal-fired power generation, which was attributable to a difference in unit production price. The unit production from green retrofitting increased to 38,121GWh/trillion won due to the reduced energy consumption and benefits of greenhouse gas reduction costs. Renewable energy producing no greenhouse gas emissions during power generation and showed the highest unit production of 75,638GWh/trillion won, about 5.74 times more effective than bituminous coal-fired power generation.

• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.131-135
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• 2005

Under sulfur deprived conditions, PS II and photosynthetic $O_2$ evolution by Chlamydomonas reinhardtii UTEX 90 are inactivated, resulting in shift from aerobic to anaerobic condition. This is followed by hydrogen production catalyzed by hydrogenase. We hypothesized that the photosynthetic capacity and the accumulation of endogenous substrates such as starch for hydrogen production might be different according to cell age. Accordingly, we investigated (a) the relationships between hydrogen production, induction time of sulfur deprivation, increase of chlorophyll after sulfur deprivation, and residual PS II activity, and (b) the effect of initial cell density upon sulfur deprivation. The maximum production volume of hydrogen was 151 ml $H_2$/l with 0.91 g/l of cell density in the late-exponential phase. We suggest that the effects of induction time and initial cell density at sulfur deprivation on hydrogen production, up to an optimal concentration, are due to an increase of chlorophyll under sulfur deprivation.

• 한국기계가공학회지
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• 제15권4호
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• pp.83-92
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• 2016

The Korean government has been making efforts to use renewable energy to reduce the consumption of fossil fuels for the heating system in greenhouses. The number of greenhouses that installed a geothermal heat pump system is 201 EA with the volume of 132.8 ha and 108,467kW from 2010-2014. The geothermal system, called a shallow geothermal system, with the temperature of $10-20^{\circ}C$ has accessories composed of a BHE and heat pump. Moreover, it is necessary to have a wide area to install the BHE and to drill to the depth of 200 m. On the other hand, even though the deep geothermal system needs a high drilling cost to obtain the temperature of $40-150^{\circ}C$, the system has the advantages of the small area required for the BHE and operation without a heat pump. In this study, the temperature of the return water and heat capacity were measured to obtain the geothermal energy efficiently on the condition of the water flow being changed in the BHE. The temperature according to the return water changes through the heat conduction based on the increase of ground temperature up to the underground depth has been calculated to conduct a simulation and is compared with the field experiment test results.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권2호
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• pp.146-153
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• 2006

A passive microfluidic delivery system using hydrophobic valving and pneumatic control was devised for microfluidic handling on a chip. The microfluidic metering, cutting, transport, and merging of two liquids on the chip were correctly performed. The error range of the accuracy of microfluid metering was below 4% on a 20 nL scale, which showed that microfluid was easily manipulated with the desired volume on a chip. For a study of the feasibility of biochemical reactions on the chip, a single enzymatic reaction, such as ${\beta}-galactosidase$ reaction, was performed. The detection limit of the substrate, i.e. fluorescein $di-{\beta}-galactopyranoside$ (FDG) of the ${\beta}-galactosidase$ (6.7 fM), was about 76 pM. Additionally, multiple biochemical reactions such as in vitro protein synthesis of enhanced green fluorescence protein (EGFP) were successfully demonstrated at the nanoliter scale, which suggests that our microfluidic chip can be applied not only to miniaturization of various biochemical reactions, but also to development of the microfluidic biochemical reaction system requiring a precise nano-scale control.

• Bulletin of the Korean Chemical Society
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• 제23권3호
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• pp.447-453
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• 2002

In this paper we have presented the results of thermodynamic, structural, and dynamic properties of model systems for liquid benzene, toluene and p-xylene in an isobaric-isothermal (NpT) ensemble at 283.15, 303.15, 323.15, and 343.15 K using molecular dynamics (MD) simulation. This work is initiated to compensate for our previous canonical (NVT) ensemble MD simulations [Bull. Kor. Chem. Soc. 2001, 23, 441] for the same systems in which the calculated pressures were too low. The calculated pressures in the NpT ensemble MD simulations are close to 1 atm and the volume of each system increases with increasing temperature. The first and second peaks in the center of mass g(r) diminish gradually and the minima increase as usual for the three liquids as the temperature increases. The three peaks of the site-site gC-C(r) at 283.15 K support the perpendicular structure of nearest neighbors in liquid benzene. Two self-diffusion coefficients of liquid benzene via the Einstein equation and via the Green-Kubo relation are in excellent agreement with the experimental measures. The self-diffusion coefficients of liquid toluene and p-xylene are in accord with the trend that the self-diffusion coefficient decreases with increasing number of methyl group. The friction constants calculated from the force auto-correlation (FAC) function with the assumption that the fast random force correlation ends at time which the FAC has the first negative value give a correct qualitative trends: decrease with increase of temperature and increase with the number of methyl group. The friction constants calculated from the FAC's are always less than those obtained from the friction-diffusion relation which reflects that the random FAC decays slower than the total FAC as described by Kubo [Rep. Prog. Phys. 1966, 29, 255].

• Asian-Australasian Journal of Animal Sciences
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• 제18권4호
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• pp.497-501
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• 2005

An experiment was conducted on crossbred male calves to study the effect of arsenic (As) on immunity status and certain hematological parameters. Ten crossbred male calves of 3-4 months of age were distributed into two equal groups. Group I was kept as control, whereas, group II was supplemented daily with 50 ppm As (as $As_sO_3$) up to 90 days, in the diet. Calves of both groups were fed as per ICAR standards and their requirements were fulfilled by feeding concentrate mixture and green oats. All calves were kept under similar managemental conditions. Blood samples were collected at fortnightly intervals to estimate various haematological parameters and superoxide dismutase (SOD) enzyme activity. Serum Ig and serum glutamic pyruvate transaminase (SGPT) were also measured. Cell-mediated immune responses of the calves were monitored at 0, 45 and 90 of experimental feeding, through lymphocyte proliferation. No change in blood total leukocyte counts (TLC), differential leukocyte counts (DLC), packed cell volume (PCV), haemoglobin (Hb) and SGPT was observed with As supplementation. A decrease in SOD activity was noticed in group II calves. Stimulation index (SI) for lymphocyte proliferation decreased from 1.14 to 0.79 in group II calves during 90 days experimental feeding, whereas, there was no change in SI values in group I indicating significant decrease in immune response of As supplemented calves. Blood As concentration increased in group II calves with the decrease in immune response. Short term supplementation of As to growing calves suggested suppressive effects on cell-mediated immunity. However, long term experiments are required to demonstrate clearly the efects of this toxic metal in calves.

• 대한환경공학회지
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• 제30권10호
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• pp.984-991
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• 2008

본 연구에서는 다공성 포화매질내에서 페놀의 제거를 위해 효소 중합반응의 적용성을 조사하였다. 페놀로 오염된 지하수의 모의실험으로 실험실 규모의 모래 충진 칼럼(ID: 4.1 cm, 충진높이: 12 cm)에 HRP와 과산화수소수를 주입하여 페놀 제거율 및 고분자 생성율에 대한 효소량(0$\sim$2 AU/mL), 이온강도(5$\sim$100 mM), pH(5$\sim$9)의 영향을 평가하였다. 페놀의 제거율은 효소량 2.0 AU/mL, 이온강도 20 mM, pH 7에서 각각 유입농도의 90% 이상을 유지하였다. 유입페놀은 다공성 매질에 축적되는 불용성 고분자와 유출되는 용해성 고분자들로 변환되었다. 최대 약 8%의 공극부피가 고분자화 반응으로부터 생산된 불용성 고분자에 의해 감소되었다.

• Journal of the Korean Wood Science and Technology
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• 제19권4호
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• pp.34-42
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• 1991

Protection of tropical forest affects on significant reduce of tropical hardwood supply, and softwood resources will be increasingly important for the timber security in Korea. U.S. softwood log was most favorite species for Korean softwood log importers in overall import conditions except price stablization and consistency of export policy. Reduced export volume from Pacific Northwest to Korean market has been immediately replenished by rediata pine from New Zealand and Chilean plantation. Siberian timber will hardly play major roles in Korean timber market unless budding structure. softwood plywood and softwood furniture uses are enhanced. Recent rapid rise of labor cost and reducing tariff rrate in Korea provided better opportunities for import lumber in building materials market. Dry dimension lumber was relatively profitable when processed from import U.S. soft-wood log while green lumber was favorable products processed from radiata pine log in Korean lumber market. This means U.S. softwood lumber would have better opportunity to market for '2${\times}$'4 studs when wood frame housing is introduced. On the other hand while radiata pine is competitive on temporary construction lumber such as supporter and concrete forming frame in Korea. Shortage of raw material for the new capacity of board plants in Korea will be it bottle neck. Major log export countries to Korea as U.S. New Zealand and Chile showed high trade intensity indices of composite hoard produces for Korean market. As Korea efforts to diversify import sources, and tariffs are reduced to 8% as scheduled by 1994. countries of scoring higher comparative advantages as Portugal. Brazil, Austria as well as New Zealand will have better opportunity to penetrate into promised Korean composites hoard market.

• 공업화학
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• 제20권2호
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• pp.117-125
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• 2009

차세대 청정 연료로 각광받고 있는 천연가스를 자동차 등의 이동원의 동력원으로 사용하기 위해 높은 에너지 밀도로 저장하는 것은 매우 중요하다. 특히 상온 및 과히 높지 않은 압력(35~40 기압)에서 흡착을 이용하여 천연가스를 저장(ANG)하는 것은 압축에 의한 CNG 및 냉각에 의한 LNG에 비해 경제적이고 안전하며 사용이 용이한 특성이 있다. 그러나 상업적으로 통용되기 위해 필요한 저장 용량을 얻을 수 있는 경제적인 흡착제가 현재 알려져 있지 않아 다양한 연구가 계속되고 있다. 최근에 많은 연구가 되고 있는 MOF (metal-organic frameworks)를 포함한 나노 세공체도 하나의 답이 될 수 있다. 본 총설에서는 ANG 밀도를 높이기 위해 필요한 흡착제의 물성과 상업적으로 적용하기 위해 요구되는 흡착제 물성에 대해 요약하였다. 높은 에너지 밀도를 위해서는 넓은 표면적, 큰 미세 세공 부피, 적당한 세공 크기 및 높은 밀도 등이 필요하고 낮은 흡탈착 에너지 및 빠른 흡탈착 속도가 요구된다. 또한 탈착시 상압에서 잔존하는 천연가스의 양이 적어 실제 활용할 수 있는 천연가스의 양(delivery)이 높아야 한다. 현재 매우 활발히 연구되고 있는 나노 세공체를 천연가스 저장물질로 적용하고자 하는 연구도 다양하게 이루어지고 있으며 이러한 물성을 만족하는 나노세공체가 개발되기를 기대한다.