• 한국수소및신에너지학회논문집
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• 제35권3호
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• pp.290-299
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• 2024

In this study, a theoretical study was conducted on the pre-cooling temperature of hydrogen gas and the heat exchanger area in a small-scale liquefied hydrogen system. The small-scale liquefaction system was built and liquid hydrogen production experiments were performed. In this process, the temperature of precooled hydrogen gas was measure to be about 120 K, and then the possibility of a cause was analyzed through pressure analysis of hydrogen gas and container, and analysis of the amount of liquid hydrogen produced. It was found that some reasonable results were obtained from the theoretical approaches. Based on this theoretical approach, we aim to improve the production of liquid hydrogen by optimizing the heat exchange area according to flow rate.

• Preventive Nutrition and Food Science
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• 제20권4호
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• pp.292-297
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• 2015

The objective of this study was to compare the effects of adding lactic acid and pectinase, and chaptalization for the quality of apple wine and the production of hazardous compounds (methanol and acetaldehyde). The pH of all of the samples was below 4; therefore, mash seemed to be fermented without any issue. Total acidity was the highest in sample A due to lactic acid addition. Pre-treated groups (samples B, C, and D) showed higher total acidities than that of the control (P<0.05). Pre-treatments might influence the production of organic acids in apple wines. The control and pectinase added sample (sample B) had the lowest alcohol contents. Adding lactic acid produced more alcohol, and chaptalized samples produced more alcohol due to the addition of sugar. Adding pectinase with and without chaptalization was not effective for producing more alcohol. The control sample had significantly higher acetaldehyde content (2.39 mg/L) than the other samples (1.00~2.07 mg/L); therefore, pre-treatments for apple wine fermentation produced a lower amount of acetaldehyde. Among the pre-treated samples, samples C and D showed the lowest acetaldehyde content of 1.00 mg/L and 1.16 mg/L, respectively. On the other hand, a significantly higher amount of methanol was generated for sample A (1.03 mg/L) and sample D (1.22 mg/L) than that of the control (0.82 mg/L) (P<0.05). Adding lactic acid or chaptalization was effective in reducing methanol and acetaldehyde in apple wines.

• 한국기계가공학회지
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• 제7권3호
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• pp.61-66
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• 2008

For the production of urethane prepolymer, the effect of process parameters such as diisocyanate MDI and polyol TDI was tested. In this paper, design of experiments has been adopted for studying the effect of the process parameters on the improvement of NCO and viscosity of pre-polymer. As a result of comparison of different parameters, the effect of polyol was stronger than that of isocyanate in comparison of reactivity according to the amounts of isocyanate and polyol. Especially, NCO and viscosity of pre-polymer affected a product safety.

• Asian-Australasian Journal of Animal Sciences
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• 제1권2호
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• pp.65-71
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• 1988

This study reports light and electron microscope examination of rumen fungal colonization of alkali-treated roughage feeds incubated in decron bags in the rumen of cannulated sheep for varying time intervals. Six roughages, pre-treated with ammonium hydroxide or sodium hydroxide at 4% (w/w) level were examined together with untreated control samples. Alkali pre-treatment was associated with an earlier and more pronounced fungal colonization than all control roughages. Sodium hydroxide pre-treatment was significantly more effective than ammonium hydroxide in improving the susceptibility of roughages to rumen fungal colonization and studies by SEM showed that the pre-treatment permitted greater penetration of feeds by fungi. Sodium hydroxide pre-treatment also significantly increased dry matter disappearance from feed held in Dacron bags in the rumen with all feeds except Lucerne stem. It is not known to what extent fungal activity contributed to increased breakdown of the feeds.

• 생명과학회지
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• 제28권6호
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• pp.738-744
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• 2018

제주조릿대는 한라산 일대에서 자생하는 제주특산식물이다. 예로부터 조릿대 잎은 다양한 약리효과를 가지고 있어 전통의약에서 사용되어 왔을 뿐만 아니라 최근에는 식품 및 화장품 소재로서 활용되고 있다. 우리 연구팀은 제주조릿대 잎의 효율적인 산업적 활용을 촉진하기 위하여 열수 추출한 후 남는 잔사로부터 식물화합물을 다량으로 함유한 잔사 추출물(PRE)을 제조하는 방법을 보고한 바 있다. 본 연구는 PRE 및 분획물이 항산화 혹은 항염소재로서 활용 가능성을 평가하기 위하여 수행하였다. PRE 에틸아세테이트 분획물(EPRE)은 DPPH, ABTS, superoxide 자유기 소거활성이 우수하였고, LPS로 자극한 RAW 264.7 세포에서 활성 산소종(ROS)과 nitric oxide (NO) 생성을 효과적으로 억제하였다. EPRE는 nuclear factor E2-related factor 2 (Nrf 2)의 핵내 이동을 증가시킴으로써 heme oxygenase-1 (HO-1)의 발현을 유도하였다. HO-1 저해제인 zinc protoporphyrin (ZPP)은 EPRE에 의한 NO 생성 저해 능을 감소시키기 때문에 HO-1이 NO 생성 억제에 관여함을 알 수 있었다. 본 연구결과는 PRE와 EPRE가 항산화 및 항염 소재로서의 활용 가능성을 제시해 준다.

• Animal Bioscience
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• 제35권3호
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• pp.494-502
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• 2022

Objective: The objective of this study was to evaluate functional properties of reduced-salt pork meat products made of pre-rigor pork loin treated by different freezing temperatures (-30℃ and -70℃) during storage. Methods: Pre-rigor cured pork loin with 1.0% added salt was compared to post-rigor muscle added with 1.5% salt for pH, color (L^*, a^*, b^*), cooking loss (CL), expressible moisture, warner-Bratzler shear value, thiobarbituric acid reactive substances (TBARS), and volatile basic nitrogen (VBN). Results: Pre-rigor cured pork loins had higher pH and temperature than post-rigor ones as raw meat (p<0.05). pH values were higher for pre-rigor pork loins than those of post-rigor pork loins (p<0.05). Color values did not different among treatments (p>0.05). No color differences were observed during storage period after cooking (p>0.05). The CL (%) of pre-rigor cured pork loins was the lowest when frozen at -70℃. The TBARS and VBN increased from 8 weeks of storage (p<0.05), but no further changed thereafter (p>0.05). Pre-rigor cured pork loins added with 1.0% salt showed similar characteristics to post-rigor pork loins added with 1.5% salt. Conclusion: Cured pork loins could be produced using pre-rigor muscle added with 1/3 of the original salt level (1.5%) and could be stored for up to 4 wks of frozen storage, regardless of a frozen temperature of -30℃ or -70℃ without detrimental effects.

• Nuclear Engineering and Technology
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• 제32권4호
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• pp.361-371
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• 2000

The 123Te(p,n)123I, 124Te(p,n)124I and 124Te(p,2n)123I reactions, among the many reaction channels opened, are the major reactions under consideration from a diagnostic purpose because reaction residuals as the gamma emitters are used for most radiophamaceutical applications involving radioiodine. Based on the available experimental data, the absorption cross sections and elastic scattering angular distributions of the proton-induced nuclear reaction on Te isotopes below 60 MeV are calculated using the optical model code APMNK. The transmission coefficients of neutron, proton, deuteron, trition and alpha particles are calculated by CUNF code and are fed into the GNASH code. By adjusting level density parameters and the pair correction values of some reaction channels, as well as the composite nucleus state density constants of the pre-equilibrium model, the production cross sections and energy-angle correlated spectra of the secondary light particles, as well as production cross sections and energy distributions of heavy recoils and gamma rays are calculated by the statistical plus pre-equilibrium model code GNASH. The calculated results are analysed and compared with the experimental data taken from the EXFOR. The optimized global optical model parameters give overall agreement with the experimental data over both the entire energy range and all tellurium isotopes.

• 디지털콘텐츠학회 논문지
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• 제19권5호
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• pp.971-979
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• 2018

현재 가상현실 영상콘텐츠는 관련 하드웨어와 소프트웨어의 빠른 성장으로 사용자 수가 빠르게 늘고 있다. 이에 가상현실 애니메이션 또한 영상콘텐츠 분야 중 빠르게 가상현실 기술과 융합하여 새로운 형태로 제작되고 있다. 현재 가상현실 애니메이션 관련 연구는 영화의 기술적인 제작 방법과 연출법 등에 집중되어 왔으며 효율적인 VR 애니메이션 제작을 위한 파이프라인을 정리한 연구는 아직 없었다. 이에 본 연구에서는 가상현실 애니메이션 중에서도 프리렌더 방식의 VR 애니메이션의 효율적인 제작을 위하여 기존 3D 애니메이션의 제작 파이프라인과의 비교를 통하여 프리렌더 VR 애니메이션 파이프라인의 특성을 도출하였다. 이를 통하여 효율적인 프리렌더 VR 애니메이션의 제작을 위해서 VR 애니메이션의 제작 과정에 적합한 프로덕션과 포스트 프로덕션 과정의 유기적인 통합과 Render Pass를 활용한 렌더링 시간의 단축을 제시하여 효과적인 Pipeline을 제시하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제24권4호
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• pp.540-572
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• 2011

The present review focuses on the effects of energy intake on performance, changes in body tissue during lactation, and metabolic parameters in dairy cows. Especially, pre-partum nutrition and its influence on lactation are emphasized. In recent decades the increase in genetic potential of dairy cows has increased milk yield. This fact sharpens the problem of a negative energy balance in early lactation because the amount of energy required for maintenance and milk production exceeds the amount of energy cows can consume. Around parturition, reduced feed intake reinforces the situation. Continuing negative energy balance causes decreasing milk yield, fertility problems, and incidence of metabolic diseases. Hence, the cow has to rely on body reserves that were stored in late lactation and the dry period. It is evident that the nutritional status pre-partum acts as the key factor for milk yield and fertility parameters in the following lactation. Cows overfed during the foregoing gestation and which have gained large quantities of body fat have lower dry matter intake along with the need to mobilize larger quantities of body reserves in lactation. The milk yield in the following lactation is lower than in cows fed according to their requirements. Cows restrictively fed in late gestation have a higher feed intake in lactation and a lower mobilization of body reserves. The effect of energy intake post-partum plays only a minor role for performance parameters in lactation. Lipid mobilized from body reserves makes a substantial contribution to the energetic cost of milk production in early lactation and adipose tissue undergoes specific metabolic alterations. Adipose tissue is degraded to free fatty acids, which are used in liver for energy purposes. High lipid mobilisation promotes the development of a fatty liver and therefore a reduced gluconeogenesis.

• International journal of advanced smart convergence
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• 제7권4호
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• pp.138-146
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• 2018

Generally, the animation and image production process consists of three stages: Pre-Production, Main-Production, and Post-Production. Real-time video production is also made based on this configuration. On the premise of the increase of productivity by reducing the production time effectively in the main production stage that takes the most time, this study aims to summarize the process of producing videos, focusing on the concrete main production stage. To do this, we propose a method for creating a real-time image from the point of view of the general user using Unity 3D, one of the game engines. Also, this study utilizes the Cinemachine feature provided by Unity 3D, which is suitable for the implementation of the proposed module structure.