High-pressure sodium (HPS) lamps have been widely used as a useful supplemental light source to emit sufficient photosynthetically active radiation and provide a radiant heat, which contribute the heat requirement in greenhouses. The objective of this study to analyze the thermal characteristics of HPS lamp and thermal behavior in supplemented greenhouse, and evaluate the performance of a horizontal leaf temperature of sweet pepper plants using computational fluid dynamics (CFD) simulation. We simulated horizontal leaf temperature on upper canopy according to three growth stage scenarios, which represented 1.0, 1.6, and 2.2 plant height, respectively. We also measured vertical leaf and air temperature accompanied by heat generation of HPS lamps. There was large leaf to air temperature differential due to non-uniformity in temperature. In our numerical calculation, thermal energy of HPS lamps contributed of 50.1% the total heat requirement on Dec. 2022. The CFD model was validated by comparing measured and simulated data at the same operating condition. Mean absolute error and root mean square error were below 0.5, which means the CFD simulation values were highly accurate. Our result about vertical leaf and air temperature can be used in decision making for efficient thermal energy management and crop growth.

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.

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.

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.

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,

Synthesized monocrystalline nanodiamond (nD) particles are heat-treated at various temperatures to produce highly structured diamond crystals. The heat-treated nDs show different weight loss ratios during thermogravimetric analysis. The crystallinities of the heat-treated nDs are analyzed using Raman spectroscopy. The average particle sizes of the heat-treated nDs are measured by a dynamic light scattering (DLS) system and direct imaging observation methods. Moreover, individual dispersion behaviors of the heat-treated nD particles are investigated based on ultrasonic dispersion methods. The average particle sizes of the dispersed nDs according to the two different measurement methods show very similar size distributions. Thus, it is possible to produce highly crystallized nD powder particles by a heattreatment process, and the nD particles are relatively easy to disperse individually without any dispersant. The heattreated nDs can lead to potential applications such as in nanocomposites, quantum dots, and biomedical materials.

In this study, two Fe-30Mn-0.2C-(1.5Al) high-manganese steels with different surface conditions were hydrogencharged under high temperature and pressure; then, tensile testing was performed at room temperature in air. The yield strength of the 30Mn-0.2C specimen increased with decreasing surface roughness(achieved via polishing), but that of the 30Mn-0.2C- 1.5Al specimen was hardly affected by the surface conditions. On the other hand, the tendency of hydrogen embrittlement of the two high-manganese steels was not sensitive to hydrogen charging or surface conditions from the standpoints of elongation and fracture behavior. Based on the EBSD analysis results, the small decrease in elongation of the charged specimens for the Fe-30Mn-0.2C-(1.5Al) high-manganese steels was attributed to the enhanced dislocation pile-up around grain boundaries, caused by hydrogen

본 연구에서는 최대한 인삼의 외형을 원형삼 형태의 홍삼 과 유사하게 유지하면서도 기능성은 증진시킬 수 있는 신속 한 고온고압 처리 공정을 확립하기 위하여 다양한 고온고압 처리공정 조건에 따른 이화학적 성분 특성 및 항산화 활성 변화를 살펴보았다. 산성다당체 및 홍삼 특유의 진세노사이 드 Rh1, Rg2, Rg3의 함량은 140℃, 3 kg/cm2의 고온고압 처리 조건에서 가장 높은 반면, 총 페놀 화합물 및 말톨 함량은 156℃, 5 kg/cm2의 고온고압 처리조건에서 가장 높았다. 그러 나 홍삼의 증자 처리 시 156℃, 5 kg/cm2의 처리조건에서는 시 료가 터지거나 외형의 변형이 심하기 때문에 140℃, 3 kg/cm2를 최적 온도 및 압력으로 설정하였다. 한편, 증자 시간이 증 가함에 따라 총 페놀 화합물, 말톨 및 흑삼특이 진세노사이드 함량은 지속적으로 증가하는 경향을 나타내었으나, 20분간 처리한 군의 외형이 기존의 홍삼과 가장 유사한 외관을 나타 냈으므로, 140℃, 3 kg/cm2에서 20분 동안 증자 처리하는 것 을 본 실험의 최적 조건으로 설정하였다. 최종적으로 이러한 최적조건을 통해 제조된 홍삼의 항산화 효능을 분석한 결과, 시중에서 판매되는 백삼, 홍삼 및 흑삼과 비교하여 높은 항산 화 성분 및 항산화 활성을 나타냈다. 따라서 본 연구를 통해 확립된 고온고압 처리를 통한 신규홍삼 제조기술은 그 형태 가 기존의 홍삼 제품과 유사하면서도 공정이 신속하고, 품질 은 흑삼과 비슷한 고기능성 신규 인삼제품 개발 시 응용 가능 한 공정으로 사료된다.

본 연구에서는 고온에서 유기용매를 정제할 수 있는 고온, 고압에서 안정한 상업화 규모의 고효율 중공사 투과증발 막, 막모듈 개발, 상업 규모의 막분리 장치시스템 개발을 수행하였는데 구성 요소기술은 1) 고온 고압 하에서 사용할 수 있는 브레이드 강화 중공사 막제조, 2) 중공사 막모듈 제조, 3) 막 탈수, 정제장치 시스템 설계 및 제작기술등을 개발하였다. 개발 중 공사 투과증발막은 독일의 슐츠막 보다 막 안정성과 막 성능이 우수하였으며, 막면적 4.6 m 2의 고효율 상업적 규모의 중공사 막모듈을 개발하였고, 200 L/hr 이상의 처리용량의 Pilot 규모의 투과증발 막장치 시스템을 개발하였다. 기존 평막 혹은 중공사 막에서 모듈에서 볼 수 있었던 모듈내부에 공급액의 dead volume형성, 공급액의 채널링 현상들을 제거하기 위해서 본 개발 중 공사막과 막모듈의 특징은 고온, 고압의 유기용매를 중공사막 내부로 공급되어 흐르도록 설계되어 있어 막분리 효율이 우수하 며 특히 기존의 막제품의 대비 막모듈 가격이 저렴하고, 막성능 및 치수안정성이 우수하다. 또한 공급액의 열손실 적어 에너지 효율이 우수할 뿐 아니라 막모듈 내에 중공사막 사이의 간격이 일정하여 가해주는 진공이 균일하게 각 중공사막의 투과부 표 면에 전달될 수 있기 때문에 투과된 투과물을 막 표면으로부터 효과적으로 제거할 수 있으므로 투과속도 또한 우수하다.

This study was conducted to develop HTHP ginseng (high temperature and high pressure ginseng) with improved antioxidative activity and phenolic acid composition by high temperature and high pressure process. The HTHP ginseng extract was analyzed for the total phenol content, DPPH radical scavenging activity and phenolic acid composition. The total phenol content was increased in HTHP ginseng (14.76 ㎎/g) compared to raw ginseng (3.59 ㎎/g) and red ginseng (3.93 ㎎/g). DPPH radical scavenging activities of HTHP ginseng, raw ginseng and red ginseng extracts were 4.8～78.4%, 1～47.4% and 1.8～56.5% at 1～100 ㎎/㎖ concentration. Also ABTS radical scavenging activities of HTHP ginseng, raw ginseng and red ginseng extracts were 8.9～99.8%, 3.4～96% and 1.2～96.5% at 1～100 ㎎/㎖ concentration. In HPLC analysis, amounts of measured phenolic acid of HTHP ginseng greatly increased than raw ginseng and red ginseng, but salicylic acid was not detected in HTHP ginseng. In addition, DPPH radical scavenging activity of phenolic acid from HTHP ginseng was increased. Consequently, we believe high temperature and high pressure process is better method than existing method to increase the bioactivity of ginseng.

Reactive oxygen species (ROS) are produced by oxidative stresses which cause various chronic diseases such as diabetes and obesity. Ginseng (Panax ginseng C.A. Mayer) has been reported to contain various biological activities such as anti-cancer, anti-diabetic, neuroprotective, radioprotective, anti-amnestic and anti-aging effects. In this study, we investigated the effects of Panax ginseng, treated with high temperatures and high pressures, on oxidative stress in C2C12 myoblasts and 3T3-L1 adipocytes. Oxidative stress was induced in the C2C12 cells through the introduction of H₂O₂ (1 mM), and cells were then treated with various ginseng preparations: dried white ginseng (DG), steamed ginseng (SG) and high temperature and high pressure treated ginseng (HG). In addition, 3T3-L1 preadipocytes were treated with various ginsengs for up to 8 days following standard induction of differentiation. Our results show that HG treatment significantly protected oxidative stress in both cell lines and enhanced gene expression of antioxidant enzymes. Therefore, in this study, we investigated the protective effects of ginseng on the oxidative stress of adipocytes and muscle cells.

Fuel test loop is an irradiation test facility which can conduct the irradiation tests of nuclear fuels and materials at HANARO. The FTL simulates the operating conditions of commercial nuclear power plants such as their pressure, temperature, flow and water chemistry to conduct the irradiation and thermo-hydraulic tests. The passivation of the fuel test loop was performed for the main cooling system in the commissioning stage with satisfaction of the operation criterion such as temperature and water chemistry conditions. The experimental results show that the passivation was completed successfully.

High Pressure High Temperature (HPHT) treatment can significantly change the color of diamonds. We studied the variation of the optical properties according to the nitrogen arrangement in natural brown diamonds of various types (type IaAB, type IaB, type IaA > B, type IaA< B, IaA = B) after HPHT treatment. The diamonds with different arrangements of nitrogen were annealed at temperatures in the range 1700-1800˚C under a stabilizing pressure of 5 GPa. HPHT treated samples were analyzed using UV-Vis-NIR, FT-IR, and PL spectroscopy. The absorption and luminescence spectra were measured to compare the variations of nitrogen arrangement in the natural brown diamonds before and after HPHT treatment. After HPHT treatment, the brown coloration in all types of diamonds was reduced and a decrease in the peaks related to the A-aggregate of nitrogen was more predominant than the B-aggregate. Furthermore, the peaks related to N3 (415.4 nm), H4 (496.4 nm), and platelet decreased and the peaks related to H3 (503.2 nm) and G-band increased after HPHT treatment. In conclusion, spectroscopic analysis of natural brown diamonds after HPHT treatment showed that a yellow color was produced by absorption in the H3 centers and a green color was generated by interaction between absorptions of the H3 and H2 centers.

The In-Pile Section(IPS) is located inside the reactor pool. It is divided into 3-parts; the in-pool pipes, the IVA(IPS Vessel Assembly) and the support structures. The test fuel is loaded inside a double wall, inner pressure vessel and outer pressure vessel, to keep the functionality of the reactor coolant pressure boundary. The IVA is manufactured by local company and the functional test and verification were done through pressure drop, vibration, hydraulic and leakage tests. A IVA has been manufactured by local technique and have finally tested under high temperature and high pressure. The IVA and piping did not experience leakage, as we have checked the piping, flanges, assembly parts. We have obtained good data during the three cycle test which includes a pressure test, pressure and temperature cycling, and constant temperature.

As of 2013, approximately 253 domestic incineration facilities including incineration facilities for municipal waste and industrial wastes were collected. The distribution of domestic incineration heat through these incineration facilities is estimated to reach about 1,756 thousands toe by 2013. In this study, a high temperature and pressure boiler was applied to evaluate the improvement effect of power generation efficiency of waste incineration facilities. It is possible to increase the power generation efficiency of the steam turbine by increasing the heat loss of the turbine through the high temperature and pressure depending on the steam pressure and the temperature. The boiler main steam amount is reduced by about 10% due to the high temperature and pressure, but the increase rate of the heat fall rate is larger than the decrease rate of the steam flow rate, so that the power generation efficiency is improved. In case of steam temperature, the steam temperature is increased by 50 ℃ at 500 ℃ and 20 kg/㎠ at the pressure of 20 kg/㎠×300 ℃, and it is increased by 10 kg/㎠ to 60 kg/㎠, electricity production changes were investigated. Electricity production increased with increasing temperature and pressure. The electricity production increased by 51.03 % at 40 kg/㎠×400 ℃ and by 89.07 % at 60 kg/㎠×500 ℃, compared to the standard condition of 20 kg/㎠×300 ℃ for comparison. The boiler main steam amount is reduced by about 10 % due to the high temperature and pressure, but the increase rate of the heat fall rate is larger than the decrease rate of the steam flow rate, so that the power generation efficiency is improved. In case of steam temperature, the steam temperature is increased by 50 ℃ at 500 ℃ and 20 kg/㎠ at the pressure of 20 kg/㎠×300 ℃, and it is increased by 10 kg/㎠ to 60 kg/㎠. Electricity production changes were investigated. Electricity production increased with increasing temperature and pressure. The electricity production increased by 51.03 % at 40 kg/㎠×400 ℃ and by 89.07 % at 60 kg/㎠×500 ℃, compared to the standard condition of 20 kg/㎠×300 ℃ for comparison.

Water temperature in the eastern part of the Yellow Sea (EYS) during winter (JFM) and summer (JJA) from 1964 to 2009 and Siberian High Pressure Index (SHI) and Arctic Oscillation index (AOI) during winter (JFM) from 1950 to 2011 were used to analyze long-term variation in oceanic and atmospheric conditions and relationship between winter and summer bottom water temperature. Winter water temperature at 0, 30 and 50 m had fluctuated highly till the late of 1980s, but after this it was relatively stable. The long-term trends in winter water temperature at both depths were separated with cold regime and warm regime on the basis of the late 1980s. Winter water temperature at 0m and 50m during warm regime increased about 0.9°C and 1.1°C respectively compared to that during cold regime. Fluctuation pattern in winter water temperature matched well with SHI and AOI The SHI had negative correlation with water temperature at 0 m (r=-0.51) and 50 m (r=-0.58). On the other hand, the AO had positive correlation with Winter water temperature at 0 m (r=0.34) and 50 m (r=0.45). Cyclic fluctuation pattern of winter water temperature had a relation with SHI and AO, in particular two to six-year periodicity were dominant from the early of the 1970s to the early of the 1980s. Before the late of 1980s, change pattern in winter water temperature at 0 and 50 m was similar with that in the bottom water temperature during summer, but after this, relationship between two variables was low.

Hepatoprotective and antioxidant activities of Acer mono and A. okamotoanum were compared after beingextracted by low temperature and high pressure (LTHP) at 20 MPa and 60℃ for 15 minutes. Extraction yield of both A.mono and A. okamotoanum was increased about 40~43% by this extraction process. On scavenging activities, the bark of A.okamotoanum from this extraction process showed the highest activity as about 97%. This value was higher than that fromconventional water extraction and A. mono extracts. Both of A. mono and A. okamotoanum showed high ability on nitritescavenging, but decreasing tendency according to increasing of pH. On SOD-like test, A. okamotoanum had the highestactivity as 46.28% at 1.0㎎/㎖ concentration. A. okamotoanum extracted by LTHP also showed the highest activity as197.38% in adding 1.0㎎/㎖ concentration. Generally, the extracts from low temperature and high pressure extraction pro-cess are higher hepatoprotective and antioxidant activities than that from conventional water extraction. It can concludethat the bark of A. okamotoanum has better biological activities than other parts of A. mo

고온-고압 상태에서 티탄철석 (FeTiO3)의 상변이에 대한 연구가 있었으나, 그 결과는 서로 일치하지 않고 있다. 특히, 티탄철석상과 페롭스카이트상의 상변이 경계는 담금방법에 의해 결정된 것으로 신뢰도에 의문이 제기되고 있다. 이러한 문제를 해결하기 위해, 고온-고압 현장상태에서 라지 볼륨 기기와 방사광을 이용하여 19 GPa와 700℃의 범위에서 X선 회절실험을 시행하였다. 이러한 실험결과, 페롭스카이트상은 상온에서 16 CPa 이상의 압력에서 안정하며, 15 CPa 근처에서 LiNbO3상으로 변이한다. 또한 이 두 고온-고압상은 500℃에서는 순간적인 상변이를 하고 있다. LiNbO3상은 각각 13 CPa 및 300'E와 10.8 GPa 및 400'E에서 티탄철석상으로 상변이 한다. 따라서 본 실험결과는 LiNbO3상은 고온-고압하에서 안정 영역을 확보하고 있으며, 페롭스카이트-티탄철석상경계는 이전에 발표된 결과와는 매우 다르다는 것을 지시해주고 있다.