• 한국식품조리과학회지
• /
• 제23권4호통권100호
• /
• pp.413-422
• /
• 2007

In this study, changes in the volatile compounds of Artemisia capillaris essential oil were investigated under six different storage conditions for 6 months. The essential oil was collected by steam distillation and analyzed by a gas chromatography-mass selective detector (GC-MSD). Seventy-five volatile compounds were identified from the fresh essential oil of Artemisia capillaris. During storage, the total levels of aldehydes, alcohols, and ketones slightly decreased and the level of hydrocarbons greatly decreased; the total level of esters also decreased in the essential oil. Notably, the levels of carvacrol, eugenol, myrcene, 1,8-cineole, caryophyllene, coumarin, ${\alpha}-thujone$, ${\beta}-thujone$, borneol, and ${\gamma}-terpinene$, known as antioxidants and antimicrobial agents, decreased during storage. Finally, aerobic storage conditions caused greater reductions in some compounds even at low temperatures.

• 한국식품영양과학회지
• /
• 제29권4호
• /
• pp.582-585
• /
• 2000

This study was performed to identify the flavor compnenets of Korean Cnidium officinale M.. The extraction of the flavor compounds of Cnidium officinale M. was accomplished by a simultaneous distillation and extraction method using a Likens and Nickerson's extraction apparatus. The concentrated extract was analyzed and identified by gas chromatography and GC-mass spectrometry. The change of the 림팩 contents in each samples was determined in terms of two different storage conditions. The flavor contents of sample at low temperature storage were higher than those at room temperature storage, and increased until storage period of 70 days. The major components of Cnidium officinale M. were terpene compounds including α-pinene, β -selinene, γ-selinene, and phthalides including butylidenephthalide, cnidilide, neocnidilide, senkyunolide A, ligustilide, which are believed to contribute to the characteristic flavor of the Cnidium officinale M.. Especially, great amount of cnidilide and ligustilide was shown in sample of low temperature storage.

• 한국수소및신에너지학회논문집
• /
• 제22권3호
• /
• pp.363-371
• /
• 2011

In this paper, a three-dimensional hydrogen desorption model is developed to precisely study the hydrogen desorption kinetics and resultant heat and mass transport phenomena in metal hydride hydrogen storage vessels. The metal hydride hydrogen desorption model, i.e. governed by the conservation of mass, momentum, and thermal energy is first experimentally validated against the temperature evolution data measured on a cylindrical $LaNi_5$ metal hydride vessel. The equilibrium pressure used for hydrogen desorption simulations is derived as a function of H/M atomic ratio and temperature based on the experimental data in the literature. The numerical simulation results agree well with experimental data and the 3D desorption model successfully captures key experimental trends during hydrogen desorption process. Both the simulation and experiment display an initial sharp decrease in the temperature mainly caused by relatively slow heat supply rate from the vessel external wall. On the other hand, the effect of heat supply becomes influential at the latter stages, leading to smooth increase in the vessel temperature in both simulation and experiment. This numerical study provides the fundamental understanding of detailed heat and mass transfer phenomena during hydrogen desorption process and further indicates that efficient design of storage vessel and heating system is critical to achieve fast hydrogen discharging performance.

• 터널과지하공간
• /
• 제21권4호
• /
• pp.287-296
• /
• 2011

본 연구에서는 압축공기에너지 지하저장을 위한 복공식 암반공동의 기밀성능을 평가할 목적으로 다상유체 열유동 해석을 수행하였다. 기밀성능은 저장공동으로부터 누출되는 공기질량으로 평가하였으며, 저장공동 내부에 콘크리트 라이닝 기밀시스템을 설치하고 저장공동은 비교적 천심도인 지하 100m 심도에 위치하는 것으로 가정하였다. 저장공동 내 질량수지분석 결과, 콘크리트 라이닝 및 주변 암반의 투과계수가 누기량 및 저장공동의 장기적 기밀성능에 미치는 영향이 큰 것으로 파악되었으며 콘크리트 라이닝의 투과계수가 $1.0{\times}10^{-18}\;m^2$이하 일 경우, 저장공동 운영압력이 5 MPa에서 8 MPa 사이일 때 누기량은 1%이하 인 것으로 계산되었다. 또한, 콘크리트 라이닝의 초기포화도에 따른 공기누출량 계산결과, 라이닝 수분포화도를 증가시킬수록 누기량은 감소하고 저장공동 기밀성능이 향상됨을 확인하였다.

• Structural Engineering and Mechanics
• /
• 제13권6호
• /
• pp.615-638
• /
• 2002

This paper presents a method of seismic analysis for a cylindrical liquid storage structure considering the effects of the interior fluid and exterior soil medium in the frequency domain. The horizontal and rocking motions of the structure are included in this study. The fluid motion is expressed in terms of analytical velocity potential functions, which can be obtained by solving the boundary value problem including the deformed configuration of the structure as well as the sloshing behavior of the fluid. The effect of the fluid is included in the equation of motion as the impulsive added mass and the frequency-dependent convective added mass along the nodes on the wetted boundary of the structure. The structure and the near-field soil medium are represented using the axisymmetric finite elements, while the far-field soil is modeled using dynamic infinite elements. The present method can be applied to the structure embedded in ground as well as on ground, since it models both the soil medium and the structure directly. For the purpose of verification, earthquake response analyses are performed on several cases of liquid tanks on a rigid ground and on a homogeneous elastic half-space. Comparison of the present results with those by other methods shows good agreement. Finally, an application example of a reinforced concrete tank on a horizontally layered soil with a rigid bedrock is presented to demonstrate the importance of the soil-structure interaction effects in the seismic analysis for large liquid storage tanks.

• 한국정보통신학회논문지
• /
• 제17권5호
• /
• pp.1129-1137
• /
• 2013

클라우드 서비스 공급자가 제공하는 클라우드 스토리지 시스템은 대량의 데이터 저장 및 클라우드 컴퓨팅 처리의 핵심구성요소이다. 구글, 유투브, 페이스북 등과 같은 대형 벤더에서도 클라우드 스토리지를 사용하여 태블릿, 스마트폰 등 이기종 장치에서 사진, 동영상, 문서등을 공유하며, 쉽고 빠르게 네트워크를 통해 데이터의 대량 전송과 접근이 가능하다. 이로 인해 전세계적으로 데이터 성장 발전과 함께 클라우드 스토리지가 비지니스모델로 새롭게 부각받고 있다. 클라우드 스토리지는 네트워크 스토리지의 새로운 서비스 개념이며 데이터 구성, 스토리지 가상화, 데이터 복제와 중복제거, 보안 등을 포함한 클라우드 컴퓨팅 핵심기술이다. 본 논문에서는 클라우드 스토리지에 대해 분석한다.

• 대한가정학회지
• /
• 제40권8호
• /
• pp.61-69
• /
• 2002

The research of the current situation of made-to-measure production by ready-made men's suit companies was done by interviewing and surveying the made-to-measure specialists. It was apparent that most frequently purchased items in Mass Customization were jackets of formal dress. The results of the research on the current situation of Mass Customization by ready-made clothes companies were as follows. The Mass Customization accounted for 3∼10%. The advantages of Mass Customization were more acceptable sizes, designs and details while the initial reasons for it were unusual physical figures and designs. The posture of a customer during measuring turned out to be critical enough to influence fitness after production. The companies in the research were found out to have materials for Mass Customization in storage and the sizes and other data of fixed circle of customers who would want Mass Customization saved in computer in most of the cases.

• 한국식품과학회지
• /
• 제25권1호
• /
• pp.52-56
• /
• 1993

$148-150^{\circ}C$의 팜유에서 약 1분간 튀겨낸 라면을 라면 $65^{\circ}C$에 저장할 때 생성되는 flavor 화합물들을 Gas Chromatography-Mass Spectrometry을 이용하여 분리, 동정하고 20, 40, $65^{\circ}C$에 저장중인 라면에서 생성되는 flavor 화합물들의 양적변화를 static headspace gas chromatography법에 의하여 측정하였다. 라면은 $65^{\circ}C$에 저장되는 동안 pentane, hexane, butanal, heptane, 1-pentanol, hexanal, octane의 화합물을 생성하였는데 이들은 주로 라면의 linoleic acid와 oleic acid로부터 생성되는 듯하다. 이들 화합물들은 저장온도가 20, 40, $65^{\circ}C$로 증가함에 따라 또한 저장기간이 경과함에 따라 그 양이 증가하는 경향을 보였으며 hexanal이 관능검사와 가장 높은 상관관계를 나타내었다(r=0.87).

• Bulletin of the Korean Chemical Society
• /
• 제35권3호
• /
• pp.811-814
• /
• 2014

Bio-oil instability, or aging, is a significant problem for the long-term storage of fast pyrolysis oils. We investigated bio-oil aging at the molecular level using Fourier-transform ion cyclotron resonance mass spectrometry. Petroleomic analysis suggests that bio-oil aging is resulted from the oligomerization of phenolic lignin products whereas 'sugaric' cellulose/hemicellulose products have negligible effect.

• Food Science and Biotechnology
• /
• 제15권5호
• /
• pp.688-693
• /
• 2006

Glucosinolates are hydrolyzed by the enzyme myrosinase and are mainly found in cruciferous vegetables such as Chinese cabbage (Brassica campestris L. ssp. pekinensis). lsothiocyanates (ITCs) are glucosinolate degradation products with reported anticarcinogenic properties. Korean Chinese cabbage in the form of 'kimchi' is a staple part of the Korean diet. In this study, we examined the effects of storage temperature and duration on glucosinolate, ITC, soluble sugar, and organic acid levels in kimchi. Changes in pH and the impact of various parts of the Korean Chinese cabbage being used during the preparation of the dish were also assessed. Extracted ITC levels, analyzed via gas chromatography (GC) and GC/mass spectrometry (GC/MS), were higher in the midrib parts than in the cabbage leaves after storage at both 4 and $20^{\circ}C$. During storage, organic acid levels increased while soluble sugars were depleted. The pH initially increased (after 1 day at $20^{\circ}C$, and 1 week at $4^{\circ}C$), but subsequently decreased over time at both temperatures. Glucosinolate and ITC levels increased in the beginning of storage but then generally fell during further storage. Our data suggest that acidity-related reduction in myrosinase activity during storage may decrease glucosinolate and ITC levels. The changes in these levels depended on the storage conditions and the Korean Chinese cabbage parts used for the kimchi preparation.