• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
• /
• pp.315-318
• /
• 2009

Hydrogen is the ideal candidate as an alternative energy carrier, so many hydrogen storage methods are investigated. The hydrogen storage method using metal hydride is good candidate as energy sources for portable devices because hydrogen-storage as metal hydride shows large volumetric storage density. In this study, we investigated the variations of hydrogen charging/discharging performance of metal hydride tanks at different temperature conditions. We charged metal hydride tanks with hydrogen in low temperature because of the exothermic reactions of hydrogen absorption while we discharged in high temperature to provide sufficient heat because of the endothermic reactions of desorption. In addition, we investigated the difference of hydrogen charging/discharging performance between two tanks having different sizes.

• 농업과학연구
• /
• 제47권3호
• /
• pp.625-632
• /
• 2020

This test was conducted to determine the appropriate conditions of temperature, storage period, and soil moisture content when using cold storage of potted mother plants of as a means of sufficient dormant breaking and safe overwintering of the strawberry (Fragaria × ananassa Duch. cv. Sulhyang) mother plants. In the treatment by temperature for the dormant breaking of strawberry mother plants, the survival rate of natural overwintering was 91%, whereas the survival rate was 100% at 0, - 2, and - 5℃. As the storage temperature was decreased, the plant height of the mother plants became shorter which tended to decrease after planting. Survival of the mother plants was possible at - 5℃, but after planting, the growth and number of daughter plants decreased significantly. The number of daughter plants was highest at 22.8 per plant at - 2℃ storage. The strawberry mother plants could be stored for up to 8 months in cold storage. However, when the mother plants were stored for a long period, the number of daughter plants was small. When they were stored for 4 months, the growth of the mother plants was vigorous, and the number of runners and daughter plants was high. When the water content of the soil was less than 10 percent (%, w/w) in the cold storage of the pot, the survival rate was 85 percent, which was high due to the dryness. The survival rate was 100 percent at 30 and above, and the growth of the mother plants after planting and the number of daughter plants were high at 30 to 50.

• 한국유기농업학회지
• /
• 제10권3호
• /
• pp.57-66
• /
• 2002

온주밀감 마착색 과실을 대상으로 고온 예조를 통해 과피의 착색 증진과 저장성 향상을 위하여 시험한 결과, 고온 예조 처리한 과실은 과피색을 촉진시켰다. 저장중 자연감량은 착색도와 관계없이 20$^{\circ}$ 예조처리 구에서 적었으며 부패과 발생은 3월 중순까지는 20$^{\circ}$ 예조 처리구에서 적었으나, 저장후기인 3월 하순부터는 효과가 없었다. 저장중 가용성고형물과 산함량은 상온 예조보다는 고온 예조구에서 높은 경향을 보였으나 각 처리간에 유의성은 없었다.

• 한국연초학회지
• /
• 제20권2호
• /
• pp.160-165
• /
• 1998

The Joint curing barns for flue-cured tobacco is a favorite with the tobacco farmers in Korea. However, most of farmer utilizing the joint curing barns indicated many problems such as high temperature and noise in the working room and a dry of cured leaves in the storage room. A structure of Joint curing barns has been modified to meet the needs of tobacco farmers. Compared with the unimproved joint curing barns, the improved one showed that the noise of workshop decreased about 7.7～10.8db, the amount of $CO_2$ decreased 40～50ppm in a working room and 80～100ppm in a machine room. Ammonia gas decreased 0.29mg/㎥ and the temperature of a working room dropped about 2.1～3.5$^{\circ}C$. The amount of air flow in a working room increased 23.2% at a site being 2m away from the entrance and 30.8% at a center. The inner temperature of the improved storage room showed that maximum temperature dropped about 3$^{\circ}C$, minimum temperature was high about 2$^{\circ}C$. The highest relative humidity was low 6%, the lowest one increased high about 10% when compared with the unimproved joint curing barns.

• 전력전자학회논문지
• /
• 제5권6호
• /
• pp.610-619
• /
• 2000

본 논문에서는 현재 전력저장시스템으로써 가장 많이 사용하고 있는 배터리를 대체할 목적의 5MB (Superconductive Magnetic Bearing)를 이용한 off-line UPS에 관해 연구하였다 영구자석의 덩어리형 고온 초전도 체위에서의 부상득성을 이용하여 베어링 문제의 해결방안에 접근함으로써 고효율의 FES찰 구성하여 단상 off-line UPS에 적용하였으며 제어회로에는 80C 1 96KC 마이크로프로세서를 사용하였고 빠픈 응답윤 요구하는 부분 은 아날로그회로를 사용하여 구성하였다. 에너지 저장모드에서 컨버터 입력천류는 전원전압과 동상의 정현파로 제어하였으며 에너지 회생모드에서는 출력잔압윤 정현파로 제어하기위해 필터커패시터전류릎 직접 제어하였다. 시작 품제작을 통해 시스템의 안장된 동작특성을 확인함으로써 제안된 FES가 Off-line UPS 에서의 에너지 저장매체로써 우수함을 입증하였다.

• 한국축산식품학회지
• /
• 제40권5호
• /
• pp.734-745
• /
• 2020

Commercially sterilized ultra high temperature (UHT) milk was manufactured at different homogenization pressures (20, 25, and 30 MPa), and changes in fat particle size, mechanical stress-induced fat aggregation, plasmin activity, and lipid oxidation were monitored during ambient storage of the UHT milk for up to 16 wk. The particle sizes of milk fat globules were significantly decreased as homogenization pressure increased from 20 to 30 MPa (p<0.05). The presence of mechanical stress-induced fat aggregates in milk produced at 20 MPa was significantly higher than for UHT milk produced at either 25 or 30 MPa. This difference was maintained all throughout the storage. There were no significant differences in plasmin activity, trichloroacetic acid (12%, w/v) soluble peptides, and the extent of lipid oxidation. Based on these results, an increase of homogenization pressure from 20 (the typical homogenization pressure employed in the Korea dairy industry) to 25-30 MPa significantly decreased mechanical stress-induced fat aggregation without affecting susceptibility to lipid oxidation during storage.

• 생명과학회지
• /
• 제17권4호
• /
• pp.510-514
• /
• 2007

정조의 저장조건에 따른 이화학적 특성의 변화에 대한 상관성을 분석한 결과는 다음과 같다. 식미관련 특성들의 상관관계에서 상온저장은 식미치와 강하점도, 취반점도와 단백질 함량 간이 유의한 정의 상관관계를 보였고, 치반점도와 강하점도, 강하점도와 단백질 함량간은 유의한 부의 상관관계를 나타내었다. 저온저장에서는 식미치와 아밀로스 함량, 호화개시온도와 단백질함량간이 유의한 정의 상관을 보였고, 식미치와 백도, 식미치와 호화개시온도, 식미치와 단백질함량 간은 유의한 부의 상관관계를 나타내었다. 식미관련 특성들이 식미치에 미치는 경로계수는 상온저장에서 직접적인 정의 효과로는 아밀로스 함량이 가장 높았으며 직접적인 부의 효과로는 단백질 함량이 가장 높았으며 다음으로 Mg/K비로 나타났다. 간접적 정의 효과로는 강하점도와 단백질 함량이 가장 높았으며 단백질 함량과 강하점도, 단백질 함량과 Mg/K비의 순이었고 간접적 부의 효과로는 호화개시온도와 Mg/K비로 가장 높았으며 백도와 Mg/K비의 순이었다. 저온저장에서 직접적인 정의 효과로는 백도가 가장 높았으며 단백질함량의 순이었고, 직접적 부의 효과로는 호화개시온도가 가장 높았으며 아밀로스 함량의 순이었다. 간접적인 정의 효과로는 호화개시온도와 아밀로스 함량이 가장 높았으며 호화개시온도와 강하점도의 순이었고 간접적인 부의 효과는 백도와 호화개시온도로 나타났으며 호화개시온도와 단백질함량의 순이었다. 식미관련특성들의 식미치에 대한 중회귀분석은 상온저장에서 단백질 함량, Mg/K비, 아밀로스 함량, 호화개시온도의 5개 요인에서 0.823의 결정계수로 가장 높게 나타났고, 저온저장에서는 수분함량, 아밀로스함량, 호화개시온도, 치반점도의 5개 요인에서 0.712의 결정계수로 가장 높게 나타났다. 24.16 kcal/mol의 값을 나타내었다.로 감소되었다(35.2% vs. 77.4%; p<0.01). 실험 2에서 다양한 정자 농도에 의한 정자 침투율과 정상 수정률을 바탕으로 판단했을 때 $4.6{\times}10^6/ml$의 정자 농도가 다른 정자 농도에 비해 난구 세포부착 난자의 체외 수정에 적합한 것으로 나타났다. 체외 수정과정에서 난구 세포 부착된 상태로 수정된 난자는 나화 난자에 비해 유의적으로(p<0.05) 높은 분할률(48.8% vs. 58.9%), 배반포 형성률(11.0% vs. 22.8%)과 배반포 세포수$(22{\pm}2\;vs.\;29{\pm}2)$를 나타내었다. 본 연구의 결과로부터 돼지의 체외 수정과정에서 난구 세포의 존재는 정자 침투를 저해하지만 분할률, 배반포 형성률 및 배반포의 세포수를 증가시키는 것으로 사료된다.수의 유출입 지점에 온도센서를 부착하여 냉각수의 온도를 측정하고 냉각수의 공급량과 대기의 온도 등을 측정하여 대사열의 발생을 추정할 수 있었다. 동시에 이를 이용하여 유가배양시 기질을 공급하는 공정변수로 사용하였다 [8]. 생물학적인 폐수처리장치인 활성 슬러지법에서 미생물의 활성을 측정하는 방법은 아직 그다지 개발되어있지 않다. 본 연구에서는 슬러지의 주 구성원이 미생물인 점에 착안하여 침전시 슬러지층과 상등액의 온도차를 측정하여 대사열량의 발생량을 측정하고 슬러지의 활성을 측정할 수 있는 방법을 개발하였다.enin과 Rhaponticin의 작용(作用)에 의(依)한 것이며, 이는 한의학(韓醫學) 방제(方劑) 원리(原理)인 군신좌사(君臣佐使) 이론(理論)에서 군약(君藥)이 주증(主症)에 주(主)로 작용(作用)하는 약물(藥物)이라는 것을 밝혀주는 것이라고

• 한국수소및신에너지학회논문집
• /
• 제34권5호
• /
• pp.431-438
• /
• 2023

Recently, study on hydrogen is being conducted due to environmental pollution and fossil fuel depletion. High-pressure gas hydrogen commonly used is applied to vehicle and tube trailers. In particular, high-pressure hydrogen storage tank for vehicles must comply with the guidelines stipulated in SAE J2601. There is a charging temperature limitation condition for the safety of the storage tank material. In this study, numerical analysis method were verified based on previous studies and the nozzle angle was changed for thermal management to analyze the increase in forced convection effect and energy uniformity due to the promotion of circulation flow. The previously applied high-pressure hydrogen storage tank has a length/diameter ratio of about 2.4 and was analyzed by comparing the length/diameter ratio with 8. As a result, the circulation flow of hydrogen flowing into the high-pressure hydrogen storage tank is promoted at a nozzle angle of 30° than the straight nozzle and accordingly, the effect of suppressing temperature rise by energy uniformity and forced convection was confirmed.

• 한국수소및신에너지학회논문집
• /
• 제33권4호
• /
• pp.391-399
• /
• 2022

Hydrogen is one of the energy carriers and has high energy efficiency relative to mass. It is an eco-friendly fuel that makes only water (H₂O) as a by-product after use. In order to use hydrogen conveniently and safely, development of production, storage and transfer technologies is required and attempts are being made to apply hydrogen as an energy source in various fields through the development of the technology. For transporting and storing hydrogen include high-pressure hydrogen gas storage, a type of storage technologies consist of cryogenic hydrogen liquid storage, hydrogen storage alloy, chemical storage by adsorbents and high-pressure hydrogen storage containers have been developed in a total of four stages. The biggest issue in charging high-pressure hydrogen gas which is a combustible gas is safety and the backfire prevention device is that prevents external flames from entering the tank and prevents explosion and is essential to use hydrogen safely. This study conducted a numerical analysis to analyze the performance of suppressing flame propagation of 2, 3 inch flame arrestor. As a result, it is determined that, where the flame arrestor is attached, the temperature would be lowered below the temperature of spontaneous combustion of hydrogen to suppress flame propagation.

• 한국수소및신에너지학회논문집
• /
• 제32권3호
• /
• pp.163-171
• /
• 2021

Securing energy sources is a key element essential to economic and industrial development in modern society, and research on renewable energy and hydrogen energy is now actively carried out. This research was conducted through experiments and analytical methods on the hydrogen filling process in the hydrogen storage tank of the hydrogen charging station. When low-temperature, high-pressure hydrogen was injected into a high-pressure tanks where hydrogen is charged, the theoretical method was used to analyze the changes in temperature and pressure inside the high-pressure tanks, the amount of hydrogen charge, and the charging time. The analysis was conducted in the initial vacuum state, called the First Cycle, and when the residual pressure was present inside the tanks, called the Second Cycle. As a result of the analysis, the highest temperature inside the tanks in the First Cycle of the high-pressure tank increased to 442.11 K, the temperature measured through the experiment was 441.77 K, the Second Cycle increased to 397.12 K, and the temperature measured through the experiment was 398 K. The results obtained through experimentation and analysis differ within ±1%. The results of this study will be useful for future hydrogen energy research and hydrogen charging station.