• 한국태양에너지학회:학술대회논문집
• /
• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
• /
• pp.256-263
• /
• 2011

Recently, curtain wall structure is constructed according to increasing high rise building. Glass is usually used in opening of curtain wall structure and window area ratio is finally increased. Excessive Daylighting and solar radiation by large window area ratio cause discomfort glare and add to cooling load in the case of office that is heavy on lighting and cooling. Therefore, this study suggests to use low transmittance window for solve those problems. Indoor lighting environment and building energy performance were analyzed by increasing transmittance from 10% to 90% and comparing fixed venetian blind. Consequently, the range of transmittance that is possible to daylighting and prevent discomfort glare. Secondary energy consumption is efficient in the case that transmittance is the range of from 20% to 50%, primary energy consumption is nice on from 20% to 40%. If those result put together, the range of window transmittance from 30% to 50% is proper in the office in lighting environment and energy consumption aspects.

• 한국전기전자재료학회논문지
• /
• 제11권10호
• /
• pp.758-762
• /
• 1998

Electrical conduction property of insulator surface is most important factor to assess the insulation performances of outdoor insulating materials. In this paper, contamination performance of the materials to be used for outdoor insulator such as porcelain, EPDM, silicone rubber was discussed by measuring properties of average leakage current and scintillation discharge pulses under salt fog conditions. The fog was applied by nozzle in chamber and fogging fluids were deionized distilled water, 0.5wt% NaCI solution and 2wt% NaCl solution. The average leakage current showed linearly with applied voltage at dry and clean surface condition. The magnitude of leakage current was almost same at different kinds of samples. In case of deionized distilled water fog, the characteristics of leakage current and applied voltage were much different to those in case of dry and clean condition with 2wt% salt fog. In case of slat fog pollution condition, the leakage current was increased above critical voltage. the scintillation discharges were also activated at the level. The leakage current and scintillation discharges were increased with increasing pollution degree. The resistance to pollution properties of silicone rubber appeared excellent among them.

• Advances in aircraft and spacecraft science
• /
• 제2권3호
• /
• pp.329-343
• /
• 2015

This study aimed to observe the effect of a novel concept (referred to as the flap extension) implemented on the leading edge of the flap of a three element high lift device. The high lift device, consisting of a flap, main element and slat is designed around an Airbus research profile for sufficient take off and landing performance of a large commercial aircraft. The concept is realised on the profile and numerically optimised to achieve an optimum geometry. Two different optimisation approaches based on Genetic Algorithm optimisations are used: a zero order approach which makes simplifying assumptions to achieve an optimised solution: as well as a direct approach which employs an optimisation in ANSYS DesignXplorer using RANS calculations. Both methods converge to different optimised solutions due to simplifying assumptions. The solution to the zero order optimisation showed a decreased stall angle and decreased maximum lift coefficient against angle of attack due to early stall onset at the flap. The DesignXplorer optimised solution matched that of the baseline solution very closely. The concept was seen to increase lift locally at the flap for both optimisation methods.

• Preventive Nutrition and Food Science
• /
• 제4권4호
• /
• pp.236-240
• /
• 1999

The characteristics of natural lactic acid fermentation of radish juice were investigated at different salt concentrations (0~2%) and temperatures (10~3$0^{\circ}C$). Major lactic acid bacteria isolated from the radish juice fermented at 2% slat concentration were Leuconostoc mesenteroides, Lactobacillus plantarum, and Lactobacillus brevis. The percentage of lactic acid bacteria against total microbe in the fermented radish juice was over 80% at 0~1% salt concentrations, suggesting the possibility of fermentation even at low salt concentration, but was still active even at 1$0^{\circ}C$. The time to reach pH 4.0 during fermentation of juice of 1% salt concentration was 281~301 hrs at 1$0^{\circ}C$ and 50-73 hrs at 3$0^{\circ}C$. The concentrations of sucrose and glucose in the fermented juice were low at high temperatures and were the lowest at a 1.0% salt concentration. However, the content of mannitol showed the opposite trend. Although sour taste, ripened taste, and acidic odor of the fermented juice showed no significant differences among various temperatures and salt concentrations, sensory values of ripened taste and sour acidic were high at high temperatures. The overall quality was the best at 1.0% salt concentration, irrespective of the temperature.

• 한국식품영양과학회지
• /
• 제23권4호
• /
• pp.625-633
• /
• 1994

In this study, processing of dried products of adcidian , Haocynthia roretzi, were investigated, which has been cultured in the south and east coast of Korea in recent years. Raw ascidians were shucked , gutted, soaked and then drained. Seven kinds of dried ascidian meats were prepared : boiled in 5% slat solution for 10 min and hot-air dried (A)-sun dried (B) or hot-air dried (C) after soaking for 1 min in 0.2% NaHSO3 solution , sun dried (D) or hot -air dried (G) after treating for 15 sec in 5% liquid smoke solution, and sun dried (E) or hot -air dried (F) after blanching for 30 sec in boiling 5% salt solution added with 0.2% NaHSO3. The moisture contents, water activity of the products showed little change and VBN gradually increased during storage at 25 $\pm$2$^{\circ}C$. The TBA and POV values of the liquid smoked dried ascidian (product D, G0 were considerably lower than those of others, In fatty acid composition 22 : 6 , 20 : 5 : 16: 0 and 18 : 1 acid were predominant. Conditions adopted in products D and G had a good antioxidative effect on highly unsatuated fatty acids during the storage. The contents of inosine and AMP of products were higher than those of other nucleotide and their related compounds. Judging from the results of chemical experiments and sensory evaluation, the sample A, D and G were most desirable and they could be preserved more than 120 days at room temperature(25$\pm$2$^{\circ}C$).

• 한국세라믹학회지
• /
• 제31권10호
• /
• pp.1218-1230
• /
• 1994

In manufacturing process of porous glass-ceramics by the filler method, the sintering behaviour of crystallizable glass powder mixed with various salts was studied and also the effects of precipitated crystal phases on the properties of porous glass-ceramics were investigated. Fine-grained crystallizable glass powder was homogeneously mixed with various slat having grain size 100~200 ${\mu}{\textrm}{m}$ and sintered for densification. After washing out the inorganic salt with distilled water, the porous sintered body was heat treated additionly for crystallization. The MgO-Al2O3-SiO2 base glass was used as crystallizable glass powder and the water soluble salts such as K2SO4 and MgSO4 were used as filler. When K2SO4 was used, leucite crystal phase was formed as a result of the ion exchange and porous glass-ceramics which exhibit high temperature resistance and high thermal expansion coefficient of 17$\times$10-6/$^{\circ}C$ could be obtained. On the contrary, when MgSO4 was used, only slight ion exchange is observed and $\mu$-cordierite and $\alpha$-cordierite crystal phases were formed and porous glass-ceramics which exhibit low thermal expansion coefficient schedule were determined with the results of DTA curves, thermal shrinkage curves and XRD patterns analysis. From DTA curves and thermal shrinkage curves, it was found that the sintering densification have been completed at the temperature range of exothermic peak for crystallization. The pore size distributions and pore diameters were measured by mercury porosimeter. The pore diameter of porous glass-ceramics was 10~15 ${\mu}{\textrm}{m}$ when 100~200${\mu}{\textrm}{m}$ grain size of K2SO4 was used and it was 25~30 ${\mu}{\textrm}{m}$ when the same grain size of MgSO4 was used. The porous glass-ceramics K2SO4 used shows bimodal pore size distribution and its porous skeleton structure was ascertained by SEM observation.

• Nuclear Medicine and Molecular Imaging
• /
• 제42권2호
• /
• pp.98-111
• /
• 2008

This review introduces advances in clinical and pre-clinical single photon emission computed tomography (SPECT) and positron emission tomography (PET) providing noninvasive functional images of biological processes. Development of new collimation techniques such as multi-pinhole and slit-slat collimators permits the improvement of system spatial resolution and sensitivity of SPECT. Application specific SPECT systems using smaller and compact solid-state detector have been customized for myocardial perfusion imaging with higher performance. Combined SPECT/CT providing improved diagnostic and functional capabilities has been introduced. Advances in PET and CT instrumentation have been incorporated in the PET/CT design that provide the metabolic information from PET superimposed on the anatomic information from CT. Improvements in the sensitivity of PET have achieved by the fully 3D acquisition with no septa and the extension of axial field-of-view. With the development of faster scintillation crystals and electronics, time-of-flight (TOF) PET is now commercially available allowing the increase in the signal-to-noise ratio by incorporation of TOF information into the PET reconstruction process. Hybrid PET/SPECT/CT systems has become commercially available for molecular imaging in small animal models. The pre-clinical systems have improved spatial resolution using depth-of-interaction measurement and new collimators. The recent works on solid state detector and dual modality nuclear medicine instrumentations incorporating MRI and optical imagers will also be discussed.

• 한국축산시설환경학회지
• /
• 제6권1호
• /
• pp.1-14
• /
• 2000

The structural and environmental characteristics of typical pig houses in different growth phases were surveyed and analyzed. Based on the data for thirty nine selected farms in four provinces, Jeonbuk-do, Jeonnam-do, Gyeongbuk-do, and Gyeongnam-do, in the southern provinces, Korea, the goal is to eventually establish standard pig houses of sow and litter, nursery pigs, and growing-finishing pigs. The survey included farm scale, production specialization, structural dimensions of the houses and their ventilation systems, cooling and heating systems, and floor and pit systems related to manure collection. The survey showed 90∼98% of growing-finishing pig houses adopted the sidewall curtain systems. The sidewall curtain systems, although popular, is not well insulated which leads to excessive heating costs in winter. Regarding flooring and manure collection system of the house, 23∼35% of growing-finishing houses installed scraper systems with concrete-slat floors in Gyeongsang provinces while 52∼78% did in Jeolla provinces. The cause of a large variance in flooring between tow regions could not be academically pinpointed, rather it could be attributed to the advice of neighbors who leads local pig production circle. A general trend toward enlargement and enclosure of pig houses for all growth phases was gaining popularity in most regions in recent years. A steady shift to multisite operation from continuous operation was also observed to prevent a disease transfer. The structural design of a standard pig house with its environmental control systems including ventilation and heating/cooling system was suggested for further validation study. In-depth analysis of the survey data is presented in the Results and Discussion section.

• 한국축산시설환경학회지
• /
• 제5권1호
• /
• pp.1-15
• /
• 1999

The structural and environmental characteristics of typical pig houses in different growth phases were surveyed and analyzed. Based on the data for thirty six selected farms in four provinces, Gyonggi-do, Gangwon-do, Choongnam, and Chonbook, in Central Korea, the goal is to eventually establish standard pig houses of sow and litter, nursery pigs, and growing-finishing pigs. The survey included farm scale, production specialization, structural dimensions of the houses and their ventilation systems, cooling and heating systems, and floor and pit systems related to manure collection. The survey showed 90∼99% of growing-finishing curtain installation rate was lower by 10∼20%. The sidewall curtain system, although popular, is not well insulated which leads to excessive heating costs in winter. Regarding flooring and manure collection system of the house, there was quite a lot variability among provinces, with 30∼80% of the houses installing scraper systems with concrete-slat floors in comparison with 30∼60% using a slurry system. Gangwon-do and Choongbook Chungwoo-goon are the predominant regions that installed a scraper system. A general trend toward enlargement and enclosure of pig houses for all growth phases was gaining popularity in most regions in recent years. A steady shift to three site production from a lumped system was also observed to prevent a disease transfer. The structural design of a standard pig house with its environmental control systems including ventilation and heating/cooling system was suggested for further validation study. In-depth analysis of the survey data is presented in the Results and Discussing section.

• 한국태양에너지학회 논문집
• /
• 제31권5호
• /
• pp.113-118
• /
• 2011

In order to prevent incoming solar radiation, it is necessary to study about blinds' blocking out effects of heat that are installed at the balcony at an apartment house. To figure out the heating effects from the windows, a study for indoor thermal environment according to the location of blinds is also needed. In order to find out the changes of indoor thermal environment, we'll compare models of a house building with or without Venetian blinds: one place has an extended living room removing a balcony and another one has a normal balcony. The result is as follows. Without blinds, the place with an extended living room has benefits for saving heat compare to the place with a normal balcony. It's because the warm air heated by the incoming solar radiation moves into the living room through convection current and radiation which causes an increase of the indoor temperature. At an extended living room, the temperature difference from outside and inside, when blinds were installed inside, was $1.9^{\circ}C$ while it was $0.6^{\circ}C$ when the blinds were installed at outside of the balcony. It is evaluated that setting up the blind outside prevents much heat. At the space with a normal balcony, installing blinds at living room windows can save much heat compare to installing blinds at windows at the balcony. The indoor temperature was low when blinds were installed. It can be said that blinds block heat from the incoming solar radiation. Moreover, when blinds are installed, there is a big change of indoor temperature due to the radiation from the blinds' slat and convective activities in between the blinds and windows. This also has to be considered.