본 연구에서는 CH4/CO2 혼합가스에서 CO2 분리를 위해 세라믹 중공사 접촉막 모듈(HFMC)을 이용하여 실험을 수행하였다. 고 내구성의 HFMC를 제작하기 위해, 고강도의 중공사막을 제조하여 평가하였다. 제조한 중공사막을 이용하여 HFMC를 제작하였고, 실험은 CH4/CO2 혼합 기체(30% CO2, CH4 balance)와 monoethanolamine (MEA)를 사용하였다. HFMC 운전 중 기체와 흡수제의 압력이 CO2 제거 효율에 어떠한 영향을 주는지 평가하였다. CO2 제거 효율은 기체압력이 증가함에 따라 같이 상승하였으며, CO2 흡수 flux 또한 액체유량과 함께 증가하는 추세를 보였다. 또한 CO2 흡수율이 40% 이하일 때 는 흡수제가 아래쪽에서 들어가는 향류형태인 LTS-1이 흡수제가 위쪽에서 들어가는 향류형태인 LTS-2보다 CO2 제거 성능 이 높았으며, 흡수율이 40% 이상일 때는 LTS-2가 LTS-1보다 성능이 높았다.

The physicochemical properties of high-pressure homogenized (microfluidized) maize starch with different preheating temperatures (50, 60oC), levels of pressure (34.5, 69, 138 MPa), and numbers of pass (1, 2, 3 pass) were examined in this study. The enzyme susceptible starch (ESS) content, morphological property, X-ray diffraction, and Rapid Visco Analyzer (RVA) profile of starch were significantly altered via increasing the number of passes and preheating temperatures. The amount of ESS and the diffraction pattern of starch indicated that the granular crystalline structure of starch was severely damaged by increasing the number of passes and preheating temperatures. The morphology of starch granule was changed from angular to spherical shape with the damaged surface as the pressure increased. Moreover, damaged starch particles gathered to form a larger mass when treated at a higher temperature with the increasing number of passes, indicating that different types and extents of damage occurred. The RVA profile of starch showed a moderate peak viscosity with increased pasting stability against shear thinning similar to that of cross-linked starch as the number of passes and preheating temperatures increased. These results suggested that microfluidization combined with preheating might be used as a potential alternative method for the modification of starch such as cross-linked starch.

This study examined the combined effects of high hydrostatic pressure (HHP) and micro-perforated (MP) film packaging on the microbiological and physicochemical qualities of kimchi sauce stored under fluctuating temperature conditions. Before storage, treatment with 600 MPa HHP reduced the total lactic acid bacteria in the sauce samples to below the detection limit (1 log CFU/g). After 68-day storage, ten microbial strains isolated from the non-treated controls were identified as Pediococcus pentosaceus, whereas eight microbial strains isolated from the HHP-treated samples were identified as Bacillus spp., regardless of the packaging type. Additionally, the samples treated with HHP and packaged in a multilayer film bag (ML-HPP), as well as those in the MP-HHP group, exhibited higher pH values and reduced sugar content than the ML-control or MP-control after 68-day storage. No significant differences were observed between the control and treatment groups regarding their electrical conductivity, salinity, and CIE a* values at the end of storage. However, there was no O2 reduction or CO2 accumulation in the MP-HHP group after 68-day storage. These results indicate that the combination of HHP treatment and MP-film packaging can extend the kimchi sauce's shelf life without packaging expansion during long-term storage.

In this paper, graphene-coated Al powders prepared by in situ reduction method were directly used for cold spraying, obtaining a graphene-reinforced Al matrix composite coating with more compact structure and better performance. Cross-sectional analysis revealed that compared with the pure Al powders, the graphene-coated Al powders were more severely deformed, and the resulting coating was denser and its porosity was reduced by over 80%. The hardness of the graphene-coated Al coating was increased by 40%, and its brine immersion time was prolonged by nearly three times. However, the graphene increases the pitting sensitivity of the Al coating; so, the enhanced corrosion resistance of the graphene-coated Al coating is mainly attributed to the improvement of its structure densification.

SiC is a material with excellent strength, heat resistance, and corrosion resistance. It is generally used as a material for SiC invertors, semiconductor susceptors, edge rings, MOCVD susceptors, and mechanical bearings. Recently, SiC single crystals for LED are expected to be a new market application. In addition, SiC is also used as a heating element applied directly to electrical energy. Research in this study has focused on the manufacture of heating elements that can raise the temperature in a short time by irradiating SiC-I2 with microwaves with polarization difference, instead of applying electric energy directly to increase the convenience and efficiency. In this experiment, Polydimethylsilane (PDMS) with 1,2 wt% of iodine is synthesized under high temperature and pressure using an autoclave. The synthesized Polycarbosilane (PCS) is heat treated in an argon gas atmosphere after curing process. The experimental results obtain resonance peaks using FT-IR and UV-Visible, and the crystal structure is measured by XRD. Also, the heat-generating characteristics are determined in the frequency band of 2.45 GHz after heat treatment in an air atmosphere furnace.

최근 일본의 건축구조기준(AIJ 2015)에서는 CFD 해석을 통한 풍하중 산정을 허용한 바 있다. 이는 컴퓨터의 연산 능력 향상 및 CFD 해석 이론의 발전으로 인해 해석의 결과가 풍동실험의 결과와 유사한 수준에 도달하였음을 뜻한다. 본 연구에서는 먼저 CFD 해석의 이론적 배경을 살펴보고, 일본의 건축구조기준 및 유럽의 과학기술연구 프로그램인 COST에서 권장한 CFD 해석 절차를 토대 로 해석을 진행하였다. 해석 결과의 신뢰성을 검증하기 위해 Tokyo Polytechnic University에서 제공하는 풍동실험 데이터를 사용하였 고, 해석과 실험의 유사성을 평가하기 위하여 형상비가 3, 4, 5일 때의 풍방향하중을 비교하였다.

필로티는 현대건축에서 주차공간의 활용, 보행자의 통로 등 여러 가지 이점을 가지고 있기 때문에 아파트와 오피스텔과 같은 고층건축물에 많이 사용되고 있다. 이러한 고층건축물의 필로티 형태 특성상 강풍이 불 때 바람이 집중되기 때문에 필로티 천장과 벽 면에 위치하고 있는 외장재 및 주골조가 파손되기 쉽다. 그리고 이러한 외장재 및 주골조의 탈락으로 인해 2차 피해가 발생할 우려가 있다. 하지만 건축구조기준(KBC-2016)에서는 고층건축물에 대한 천장 및 벽면의 풍압계수만을 제시할 뿐 필로티에 대한 기준이 명시 되어 있지 않다. 본 논문은 고층건축물에서 사용되는 필로티의 종류로서 관통형, 개방형 필로티를 선정하였고, 필로티의 폭과 깊이를 변수로 하여 풍동실험을 진행하였다. 그리고 변수에 따른 풍압계수의 특성을 파악하였고 비교 및 분석하였고 본 논문의 실험결과를 통 하여 필로티 설계 시 활용할 수 있는 주골조 및 외장재 설계용 풍압계수를 제시하였다.

A gasketed plate heat exchanger(GPHE) requires a much smaller installation space than a shell & tube heat exchanger because of its compact and good thermal performances. However, GPHEs have a disadvantage of being relatively vulnerable to high temperature and pressure due to rubber gaskets. To overcome a GPHEs’ disadvantage, Welded Block type Plate Heat Exchangers(WBPHE) have been developed. The flow pattern and heat transfer principle of WBPHE are very similar to GPHEs, so they are very compact and can be applied to high temperature and pressure. In this study, the structure and characteristics of WBPHE are briefly introduced, and its thermal performances were conducted experimentally using hot and cold water in the Reynolds number’s range from 5,500 to 10,000. Test results were compared with the experimental correlations of other researchers, which shows that significant deviations were noticed in the heat transfer coefficient predictions with a deviation range from 31% to 85%. The previous friction factor correlations also predicted the current results with big errors from 25% to 45%. These deviations are expected to be due to different chevron angles between previous studies and the current study, and also the end-plate effect is expected to be one of the potential causes that led to these deviations.

In this research, a new medium-entropy alloy with an equiatomic composition of FeCuNi was designed using a phase diagram (CALPHAD) technique. The FeCuNi MEA was produced from pure iron, copper, and nickel powders through mechanical alloying. The alloy powders were consolidated via a high-pressure torsion process to obtain a rigid bulk specimen. Subsequently, annealing treatment at different conditions was conducted on the four turn HPT-processed specimen. The microstructural analysis indicates that an ultrafine-grained microstructure is achieved after post-HPT annealing, and microstructural evolutions at various stages of processing were consistent with the thermodynamic calculations. The results indicate that the post-HPT-annealed microstructure consists of a dual-phase structure with two FCC phases: one rich in Cu and the other rich in Fe and Ni. The kernel average misorientation value decreases with the increase in the annealing time and temperature, indicating the recovery of HPT-induced dislocations.

The purpose of this study was to optimize the rice protein extracted using a response surface methodology. The experiment was designed based on a CCD (Central Composite Design), and the independent variables were the high pressure (X1, 0-400 MPa) and processing time (X2, 0-10 minutes). The results of the extraction content (Y1), residue content (Y2), and recovery yield (Y3) were fitted to a response surface methodology model (R2= 0.92, 0.92, and 0.93, respectively). Increasing the pressure and processing time has a positive effect on the extraction content (Y1), residue content (Y2), and recovery yield (Y3). Therefore, these high-pressure conditions (independent variables) can significantly affect the improvement in rice protein extraction efficiency. Thus, the optimal conditions of X1 and X2 were 400 MPa and 10 min., respectively. Under these optimal conditions, the predicted values of Y1, Y2, and Y3 were 62.93, 57.53 mg/g, and 91.76%, respectively.

This study was carried out to produce stable evening primrose oil in water emulsion by using various emulsifier with HLB (8.6, 12, 16.7), concentration (0-45%) and emulsification methods such as high-speed emulsification (7,000 rpm, 2 min) and high-pressure homogenization (10,000 psi, 1 cycle). And then properties of evening primrose oil in water emulsion was evaluated with keeping at room temperature and 40oC during 28 days. Lower HLB 8.6 and high viscosity emulsifier added emulsions were not appropriate for high-pressure homogenization and were separated in a day. The optimum emulsification condition was HLB 12 and high-pressure homogenization (10,000 psi, 1 cycle) for evening primrose oil in water emulsion. These emulsions produced by optimum condition were not separated with the aqueous phase and the oil phase and they were nano-sized around 200 nm, higher zeta-potential (±mV), mono-polydispersed (<0.3), and less oxidized (<0.4) during 28 days.

Recently, automobile washing methods have been carried out using steam of high temperature and high pressure instead of water. Therefore, it is necessary to secure the structural stability of the steam tank. In this study, it is necessary to reduce the weight of the steam tank by reducing the thickness of the existing steam tank by about 25%. The safety of the product design was verified through simulation to ensure the robustness of the product by securing the structural stability and fatigue analysis at high temperature and pressure of the steam tank according to the weight reduction. For newly developed products compared to existing models.

In this study, temperature and pressure of guided wave radar products are transmitted at high temperature and high pressure. In the case of transmission of temperature pressure, high temperature and high pressure steam leak from the guide rod part to the atmosphere causes the failure. Therefore, in this study, structural analysis and thermal flow analysis of the product are performed to identify the problem of the product, so as to prevent leakage in the product development by grasping the cause of the leakage of the product. In this study, if the method of assembling the lower end of the piston rod and the gasket is changed from line contact to face contact,

Plant growth and morphology are affected by light environments. The morphogenesis and growth of the plants growing in plant factories are different from those grown under sunlight due to the effect of far-red light included in sunlight. The objective of this study was to compare the morphogenesis and growth of cucumber plants grown under artificial sunlight, high pressure sodium lamp (HPS), and HPS with additional far-red light (HPS+FR). The artificial solar (AS) with a spectrum similar to sunlight was manufactured using sulfur plasma lamp, incandescent lamp, and green-reducing optical film. HPS was used as a conventional electrical light source and far-red LEDs were added for HPS+FR. The optical properties of each light source was analyzed. The morphogenesis, growth, and photosynthetic rate were compared in each light source. The ratio of red to far-red lights and phytochrome photostationary state were similar in AS and HPS+FR. There were significant differences in morphology and growth between HPS and HPS+FR, but there were no significant differences between AS and HPS+FR. SPAD was highest in HPS, while photosynthetic rate was higher at AS and HPS. Although the photosynthetic rate in HPS+FR was lower than HPS, the growth was similar in AS. It was because canopy light interception was increased by longer petioles and larger leaf areas induced by FR. It is confirmed that the electrical light with additional far-red light induces similar photomorphogenesis and growth in sunlight spectrum. From the results, we expect that similar results will be obtained by adding far-red light to electrical light sources in plant factories.

The 3-way valve have been used as a valve for opening and closing the valve by the flow control in the pressure system of the cryogenic and high pressure environment. In this paper, numerical analysis and experimental study on fracture nipple of 3-way ultra high pressure valve applied to space launch vehicle was carried out. We have developed a 3-way valve numerical simulation modeler of cryogenic environment using commercial software ANSYS 18.2. As results of numerical analysis, optimum nipple condition was derived. In addition, a 3-way valve prototype was fabricated and the fracture test was performed and compared with the numerical analysis results.

본 연구에서는 발아와 고압처리에 따른 검정콩 조사포닌 추출물의 in-vitro 항암 활성을 확인하기 위하여 검정콩을 발아시킨 후 고압처리하고, 조사포닌 추출물을 제조한 후 인체 유래 유방암(MCF-7), 대장암(HCT-116), 전립선암(PC-3) 및 위암(AGS) 세포주에 대한 증식억제효과를 검토하였다. 대조구의 조사포닌 추출물은 400 μg/mL 농도에서 4종의 암세포주에 대하여 67.02~91.70% 범위의 생존율을 보여 항암 효과가 낮았지만, 발아 4일차 콩을 150 MPa의 압력에서 고압처리한 검정콩의 조사포닌 추출물은 23.94~57.37% 범위의 생존율을 보여 발아와 고압처리에 의해 암세포 성정억제효과가 증가하였다. 특히, 위암세포(AGS)의 경우 다른 세포주에 비해 저농도에서도 세포증식효과를 보여 가장 높은 암세포 증식억제 효과를 나타내었다. 이상의 결과로부터 항암 활성을 나타내는 Soyasaponin, B group의 soyasaponin 및 soyasapogenol의 함량은 발아와 고압처리에 의해 증가하였고, 고압처리 발아콩으로부터 항암 활성을 나타내는 사포닌 추출물의 개발이 가능할 것으로 생각된다. 또한, 추후 항암 활성 물질의 분리동정과 메커니즘 규명에 대한 연구가 수행되어야 할 것으로 판단된다.