• Title/Summary/Keyword: specific heat

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Sensitivity Test of the Parameterization Methods of Cloud Droplet Activation Process in Model Simulation of Cloud Formation (구름방울 활성화 과정 모수화 방법에 따른 구름 형성의 민감도 실험)

  • Kim, Ah-Hyun;Yum, Seong Soo;Chang, Dong Yeong
    • Atmosphere
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    • v.28 no.2
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    • pp.211-222
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    • 2018
  • Cloud droplet activation process is well described by $K{\ddot{o}}hler$ theory and several parameterizations based on $K{\ddot{o}}hler$ theory are used in a wide range of models to represent this process. Here, we test the two different method of calculating the solute effect in the $K{\ddot{o}}hler$ equation, i.e., osmotic coefficient method (OSM) and ${\kappa}-K{\ddot{o}}hler$ method (KK). To do that, each method is implemented in the cloud droplet activation parameterization module of WRF-CHEM (Weather Research and Forecasting model coupled with Chemistry) model. It is assumed that aerosols are composed of five major components (i.e., sulfate, organic matter, black carbon, mineral dust, and sea salt). Both methods calculate similar representative hygroscopicity parameter values of 0.2~0.3 over the land, and 0.6~0.7 over the ocean, which are close to estimated values in previous studies. Simulated precipitation, and meteorological variables (i.e., specific heat and temperature) show good agreement with reanalysis. Spatial patterns of precipitation and liquid water path from model results and satellite data show similarity in general, but on regional scale spatial patterns and intensity show some discrepancy. However, meteorological variables, precipitation, and liquid water path do not show significant differences between OSM and KK simulations. So we suggest that the relatively simple KK method can be a good alternative to the OSM method that requires various information of density, molecular weight and dissociation number of each individual species in calculating the solute effect.

Octimization of Conditions of Filtration and Concentration of Methanol Extract for Recovery of Paclitaxel from Plant Cell Culture (식물세포배양으로부터 Paclitaxel 회수를 위한 메탄올 추출액의 여과 및 농축 조건 최적화)

  • Kim, Jin-Hyun
    • KSBB Journal
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    • v.22 no.4
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    • pp.197-200
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    • 2007
  • This study examined the conditions of filtration and concentration of methanol extract from biomass. Filtration efficiency was improved by adding diatomaceous earth as a filter aid. The optimal amount of diatomaceous earth was 6% (w/w) to reduce the filtration time. The filtration time was reduced by 4.2% in first extraction, 30.0% in second extraction, 22.8% in third extraction, and 19.0% in fourth extraction, respectively. The optimal temperature of water bath was below 50$^{\circ}C$ for preventing paclitaxel degradation during concentration of methanol extract using a rotary evaporator. The temperature of concentrated solution in rotary evaporator was relatively low compared to bath temperature because of latent heat of evaporation. The stopping point of concentration in rotary evaporator for the following step was at a specific gravity of 0.96 of the concentrated solution in terms of the purity and yield of paclitaxel. This information is very useful for mass extraction of biomass for the recovery of paclitaxel from plant cell culture.

A Comparative Analysys of Window Energy Performance According to the Difference Between Actual size and Standard size (창호의 성능인증 규격 기준과 면적 변화에 따른 에너지성능 비교분석)

  • Kim, Seong-Beom;Lee, Su-Yeul;Kim, Dong-Yoon;Choi, Won-Ki
    • Journal of the Korean Solar Energy Society
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    • v.40 no.1
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    • pp.49-60
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    • 2020
  • This study reviewed selected specific windows and reviewed the window performance certification criteria including KS F 2278 and KS L 9107 and analyzed the change in performance based on the change of area. This study also compared the heating and cooling loads of an apartment house applied with window performance reviewed in consideration of insulation and SHGC performance and actual size based on KS F 2278. The analyzed window was a double window composed of aluminum and PVC and the building was the apartment house model of 141 ㎡. The analysis results were as follows. First, as the window glass's thermal performance is superior to frame, the performance degraded in reduced area. In case of selected window, the 1 m × 1m window's thermal performance and SHGC decreased by 35% and 37% respectively compared to 2 m × 2 m window. Secondly, in the comparison of performance for increasing area with 2 m × 2 m and 3 m × 3 m windows, the 3 m × 3 m window's thermal performance and SHCG increased about 14%. Third, in the comparison of heating and cooling loads of the analyzed model considering the apartment house model applied with window performance derived from KS F 2278 and actual figures, the model's total heating and cooling loads increased by 33% with cooling decreasing by 36% and heating increasing by 77%. Above analysis results show that evaluation of window performance based on criteria such as KS F 2278 and KS L 9107 may lead to distortion of performances different from actual products. Thus, it is necessary to suggest new evaluation criteria.

Customers' Purchase Patterns and Expectation-Confirmation toward Home Meal Replacement Products (고객의 가정식사대용식 구매 현황 및 기대일치정도 분석)

  • Koo, Minsun;Kang, Hye-Seung;Ham, Sunny
    • Journal of the Korean Dietetic Association
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    • v.24 no.3
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    • pp.246-260
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    • 2018
  • This study examined the customers' perception on Home Meal Replacement (HMR) products. Specifically, there were three research objectives: 1. to identify the customers' HMR purchase patterns and preference of HMR product development; 2. to identify the attributes of the HMR products that the customers perceive; and 3. to examine the customers' level of expectation-confirmation toward HMR product attributes according to the demographic characteristics. This study employed a self-administered survey that was distributed online from November 21~24, 2017. The sample of the study was the customers who had purchased HMR products in the six months prior to taking the survey. A total of 553 respondents completed the survey, which was used for data analysis. The results revealed the customers' HMR purchase patterns. The major HMR product type of purchase was ready to heat (52.6%), while the main reason for purchasing HMR products was convenience (83.2%). For the differences in the level of expectation-confirmation toward HMR products in accordance with the demographic characteristics of customers, the results indicated that there was a difference in the expectation-confirmation level according to age, whereas the respondents aged 29 and under showed a significantly higher level of time-saving for the preparation and ease of cooking (P<0.05) than the other age groups. In addition, there was a significant difference in the expectation-confirmation level for saving meal preparation time (P<0.05) and convenience (P<0.01) among the customer's occupation. These findings can provide the basis for a strategy for developing HMR products reflecting the rapidly changing customers' needs. HMR products should be developed according to the specific target market, as the study indicated that the respective customer segmentation resulted in a difference in their expectation toward HMR products.

Detection of Mycobacterium avium ssp paratuberculosis in Korean Cattle by the Polymerase Chain Reaction (한우 혈액에서 PCR을 이용한 Mycobacterium avium ssp paratuberculosis의 검출)

  • Kim, Kwang-Hyun;Kwak, Kil-Han;Song, Hee-Jong;Cho, Jeong-Gon
    • Journal of Veterinary Clinics
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    • v.27 no.1
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    • pp.23-28
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    • 2010
  • Mycobacterium avium ssp paratuberculosis, intracellular bacteria that can cause chronic granulomatous enteritis in cattle, continues to pose significant economic losses and health problem with high prevalence. The purpose of this study is the polymerase chain reaction (PCR)-base strategy for early detection of M. avium ssp paratuberculosis in whole blood. Blood samples were collected from korean cattles in Jeonbuk, Korea. The 16 out of 88 serum samples were detected M. partuberculosis by ELISA. Then samples of infected 8 Korean cattles were amplified by PCR. The PCR amplified targets are 16s rDNA and heat shock protein 65kDa (hsp 65). The 16s rDNA provided a highly sensitive and specific tool for the direct detection of mycobacteria. In addition M. avium was confirmed characteristically by the hsp65. Finally there were sure to M. avium ssp paratuberculosis by IS900 PCR. The restriction fragment length polymorphism was identified by PCR amplifications and subsequence restriction enzyme digestions with Pst I of a hsp65. These results indicate that confirm M. avium with 16s rDNA, hsp65 and a restriction fragment length polymorphism in the hsp65 gene can be seem the other pattern. Therefore, these results can be used for clinical direct detections of M. avium ssp paratuberculosis in whole blood of Korean cattle and also to be used epidemiological researches.

A Study on 'Dokyeok(毒疫)' of Byeokyeoksinbang(辟疫神方) (『피역신방(辟疫神方)』의 독역(毒疫)에 대한 고찰)

  • Kim, Sang-Hyun;Jang, Woo-Chang;Baik, You-Sang;Lyu, Jeong-Ah;Jeong, Chang-Hyun
    • Journal of Korean Medical classics
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    • v.28 no.2
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    • pp.33-45
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    • 2015
  • Objectives : Through the study on Byeokyeoksinbang(辟疫神方), it would be expected to analyze Dokyeok(毒疫)'s characteristic and to comprehend how the changes in viewpoints of epidemic febrile disease were made. Methods : It has been done to analyze the original text of Byeokyeoksinbang(辟疫神方), and to compare the theory of Onbyeongjobyeon(溫病條辨) associated with the signature symptom of Dokyeok(毒疫). Results : Heo Jun(許浚) experienced a specific epidemic disease called 'Dokyeok(毒疫)', on which he made observations and analyzed its features and wrote Byeokyeoksinbang(辟疫神方). In Byeokyeoksinbang(辟疫神方), 'Dokyeok(毒疫)' is characterized by rash[疹], its pathogenesis is warm temperature, thus its treatment principle is removing interior and exterior heat. The book's pragmatic perspective is highly appreciated, as HeoJun improved and solidified existing medical knowledge up to date. In addition, Byeokyeoksinbang(辟疫神方) is significant in that it differentiated between macula[癍疹] and rash[疹], much earlier than the febrile disease school of the Qing dynasty. Conclusions : Between Byeokyeoksinbang(辟疫神方) and Onbyeongjobyeon(溫病條辨), there are differences in treatments and patterns of rash[疹]. Based on this, it will be able to compare each disease that is written in two books. And a study on comparing the development between epidemic febrile disease[瘟疫學] of the Joseon dynasty and febrile disease[溫病學] of the Qing dynasty will be carried out with a follow-up study.

CURRENT RESEARCH ON ACCELERATOR-BASED BORON NEUTRON CAPTURE THERAPY IN KOREA

  • Kim, Jong-Kyung;Kim, Kyung-O
    • Nuclear Engineering and Technology
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    • v.41 no.4
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    • pp.531-544
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    • 2009
  • This paper is intended to provide key issues and current research outcomes on accelerator-based Boron Neutron Capture Therapy (BNCT). Accelerator-based neutron sources are efficient to provide epithermal neutron beams for BNCT; hence, much research, worldwide, has focused on the development of components crucial for its realization: neutron-producing targets and cooling equipment, beam-shaping assemblies, and treatment planning systems. Proton beams of 2.5 MeV incident on lithium target results in high yield of neutrons at relatively low energies. Cooling equipment based on submerged jet impingement and micro-channels provide for viable heat removal options. Insofar as beam-shaping assemblies are concerned, moderators containing fluorine or magnesium have the best performance in terms of neutron accumulation in the epithermal energy range during the slowing-down from the high energies. NCT_Plan and SERA systems, which are popular dose distribution analysis tools for BNCT, contain all the required features (i.e., image reconstruction, dose calculations, etc.). However, detailed studies of these systems remain to be done for accurate dose evaluation. Advanced research centered on accelerator-based BNCT is active in Korea as evidenced by the latest research at Hanyang University. There, a new target system and a beam-shaping assembly have been constructed. The performance of these components has been evaluated through comparisons of experimental measurements with simulations. In addition, a new patient-specific treatment planning system, BTPS, has been developed to calculate the deposited dose and radiation flux in human tissue. It is based on MCNPX, and it facilitates BNCT efficient planning based via a user-friendly Graphical User Interface (GUI).

IRRADIATION PERFORMANCE OF U-Mo MONOLITHIC FUEL

  • Meyer, M.K.;Gan, J.;Jue, J.F.;Keiser, D.D.;Perez, E.;Robinson, A.;Wachs, D.M.;Woolstenhulme, N.;Hofman, G.L.;Kim, Y.S.
    • Nuclear Engineering and Technology
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    • v.46 no.2
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    • pp.169-182
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    • 2014
  • High-performance research reactors require fuel that operates at high specific power to high fission density, but at relatively low temperatures. Research reactor fuels are designed for efficient heat rejection, and are composed of assemblies of thin-plates clad in aluminum alloy. The development of low-enriched fuels to replace high-enriched fuels for these reactors requires a substantially increased uranium density in the fuel to offset the decrease in enrichment. Very few fuel phases have been identified that have the required combination of very-high uranium density and stable fuel behavior at high burnup. U-Mo alloys represent the best known tradeoff in these properties. Testing of aluminum matrix U-Mo aluminum matrix dispersion fuel revealed a pattern of breakaway swelling behavior at intermediate burnup, related to the formation of a molybdenum stabilized high aluminum intermetallic phase that forms during irradiation. In the case of monolithic fuel, this issue was addressed by eliminating, as much as possible, the interfacial area between U-Mo and aluminum. Based on scoping irradiation test data, a fuel plate system composed of solid U-10Mo fuel meat, a zirconium diffusion barrier, and Al6061 cladding was selected for development. Developmental testing of this fuel system indicates that it meets core criteria for fuel qualification, including stable and predictable swelling behavior, mechanical integrity to high burnup, and geometric stability. In addition, the fuel exhibits robust behavior during power-cooling mismatch events under irradiation at high power.

Preparation and Thermal Characteristics of Hexadecane/xGnP Shape-stabilized Phase Change Material for Thermal Storage Building Materials (축열건축자재 적용을 위한 Hexadecane/xGnP SSPCM 제조 및 열적특성)

  • Kim, Sug-Hwan;Jeong, Su-Gwang;Lim, Jae-Han;Kim, Su-Min
    • Journal of the Korean Solar Energy Society
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    • v.33 no.1
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    • pp.73-78
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    • 2013
  • Hexadecane and exfoliated graphite nanoplate (xGnP)composite was prepared as a shape-stabilized phase change material (SSPCM) in a vacuum to develope thermal energy storage. The Hexadecane as an organic phase change material (PCM) is very stable against phase separation of PCM and has a melting point at $18^{\circ}C$ that is under the thermally comfortable temperature range in buildings. The xGnP is a porous carbon nanotube material with high thermal conductivity. Scanning electron microscope (SEM) and Fourier transformation infrared spectrophotometer (FT-IR)were used to confirm the chemical and physical stability of Hexadecane/xGnP SSPCM. In addition, thermal properties were determined by Deferential scanning calorimeter(DSC) and Thermogravimetric analysis (TGA). The specific heat of Hexadecane/xGnPSSPCM was $10.0J/g{\cdot}K$ at $21.8^{\circ}C$. The melting temperature range of melting and freezing were found to be $16-25^{\circ}C$ and $17-12^{\circ}C$. At this time, the laten heats of melting and freezing were 96.4J/g and 94.8J/g. The Hexadecane was impregnated into xGnP as much about 48.8% of Hexadecane/xGnP SSPCM's mass fraction.

The Efficiency of RNA Interference in Bursaphelenchus xylophilus

  • Park, Jung-Eun;Lee, Kyong Yun;Lee, Se-Jin;Oh, Wan-Suk;Jeong, Pan-Young;Woo, Taeha;Kim, Chang-Bae;Paik, Young-Ki;Koo, Hyeon-Sook
    • Molecules and Cells
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    • v.26 no.1
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    • pp.81-86
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    • 2008
  • RNA interference (RNAi) was performed on several essential genes in the pinewood nematode Bursaphelenchus xylophilus, which causes pine wilt disease. Double-stranded RNA (dsRNA) was delivered to larvae or adult worms by soaking, electroporation, or microinjection. Soaking and electroporation of L2-L3 stage worms in solutions containing dsRNA for essential genes induced over 25% lethality after 5 days, and gene-specific phenotypes were observed. This lethality agreed with significant reductions of the targeted transcripts, as assayed by reverse-transcription coupled with real time PCR. Microinjection was the most efficient route as measured by the hatching rate of F1 embryos, which was reduced by 46%. When adult worms were soaked in dsRNA, lethality was induced in the F1 larvae, revealing the persistence of knockdown phenotypes. The penetrance of the RNAi phenotypes for essential genes was relatively low but consistent, indicating that RNAi should be useful for studying the in vivo functions of B. xylophilus gene products.