• 한국산학기술학회논문지
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• 제16권10호
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• pp.6759-6765
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• 2015

본 연구에서는 자연외기를 활용하여 건물의 중앙냉방시스템에 대한 에너지를 절약하기 위한 제어방법으로서 외기온도 조건을 고려한 나이트 퍼지제어의 적용방안에 대해 시뮬레이션 연구가 수행되었다. 외기온도의 변화특성 및 건물의 축냉성능 등이 고려되었으며, 나이트 퍼지제어를 위한 운전시작시간과 제어설정온도의 선정방안이 연구되었다. 본 연구를 위하여 TRNSYS 프로그램을 활용하여 시스템 해석 모델링을 수행하였으며, 기존 제어방식 대비 제안된 제어방법의 에너지 절약성능을 비교 분석하였다. 연구결과로 외기온도 변화에 따라 나이트 퍼지제어를 위한 운전조건을 선정한 제안된 제어방법이 기존의 나이트 퍼지제어 제어방식과 비교하였을 때는 최대 16.8%, 나이트 퍼지제어를 적용하지 않은 경우에 비해서는 최대 28.6%의 에너지 절감이 가능함을 알 수 있었다.

• Journal of Biosystems Engineering
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• 제19권4호
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• pp.358-368
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• 1994

Major factors in reducing the stacking strength of corrugated fiberboard boxes in cold storage or transport conditions are high relative humidity, causing elevated moisture absorption by the boxes. The bottom boxes in a stack will deform to the critical deflection causing agricultural products damage there, and eventually additional deflection will cause box collapse and finally toppling of the stack. The study was conducted to determine the water absorption characteristics and the compressive strength of the corrugated fiberboard boxes being widely used in packaging agricultural products in Korea. The sample boxes for the study were selected from the regular slotted containers (RSC) types, and one was the box used in apple packaging (Box A), another one was the box used in pear packaging (Box B). The corrugated shipping containers were made from a large portion of recycled fibers in Korea, and comparing with Box B, Box A was fabricated from fiberboard which contained more percentage of old corrugated containers (OCC) imported from foreign countries than domestic waste paper. The results obtained from the study were summarized as follows ; 1. Equilibrium moisture content (EMC) of the sample boxes was established after about 20 hours, and the EMC by absorption was lower than that by desorption. The EMC increased with the increasing of relative humidity and with the decreasing of temperature, and the rate of increasing was much higher above the relative humidity of 50%. 2. The maximum compressive strength of Box A was about 100 kgf greater than that of Box B on the same enviromental conditions. The strength of the sample boxes decreased rapidly with the increasing of relative humidity. The effect of relative humidity on the strength was a little higher than that of temperature. 3. As the applied load was progressively increased and a level was reached, the vertical side panels ($L{\times}D$) deflected laterally inwards or outwards. The panels deflected laterally inwards at higher relative humidity. 4. The maximum compressive deflection ratio and the critical deflection ratio of the sample boxes were increased linearly with the increasing of relative hunidity, but trends for its ratios showed inconsistant response to temperature.

• 터널과지하공간
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• 제26권1호
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• pp.12-23
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• 2016

향후 국내에서 수행될 이산화탄소 지중저장 프로젝트의 성공적인 수행을 위해서는 현장 지질조건에 최적화된 주입 조건을 설계하는 것이 중요하다. 따라서 본 연구에서는 주입량 및 주입온도 등의 주입조건이 격리저장시스템의 역학적 안정성에 미치는 영향을 열-수리-역학 연계해석기법의 하나인 TOUGH-FLAC 해석기법을 이용하여 평가하였다. 저장시스템의 역학적 안정성은 기존 균열의 전단미끄러짐 발생가능성을 활동마찰각 및 응력원을 이용하여 분석하였다. 이산화탄소의 주입온도가 저류층의 초기온도보다 낮은 저온주입의 조건에도 열응력으로 인한 인장균열은 발생하지 않는 것으로 파악되었으나, 저류층에서 전단미끄러짐이 발생하는 결과를 보였다. 단위시간당 이산화탄소 주입량을 변화시킨 시나리오 해석에서는 단계별로 주입량을 감소시키는 주입시나리오에서 기존 균열들의 전단미끄러짐 발생 가능성이 가장 낮은 것으로 평가되었다.

• 한국식품조리과학회지
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• 제15권6호
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• pp.579-585
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• 1999

This study was conducted to evaluate the recognition of HACCP(Hazard Analysis Critical Control Point) concept by the industry foodservice managers in Pusan and the Kyung Nam areas and to suggest a guideline for an effective HACCP education program. A survey was conducted from 133 foodservice managers by using a questionnaire. The results were as follows; 68.0% industry foodservice managers were educated about HACCP concept, 33.8% didn't understand the concept, and only 13.4% understood the concept fully. On the application of HACCP program to the foodservice operation, 15.0% of managers always applied HACCP program, 35.4% often, and 49.6% did not. The reasons for not applying HACCP were the ignorance HACCP implementation method(36.7%), poor facilities of foodservice operations(34.7%), shortage of time(l4.3%), and difficult of HACCP principles(6.1%). The mean score of HACCP knowledge for all manager was 64.1, in which the educated manager showed significantly higher score than noneducated CP(0.01). The ratio of correct answers concerning HACCP was 80.5% for the pre-preparation stage, 60.3% for the receiving and storage stage, 57.0% for the hot and cold holding stage, 54.5% for the facilities sanitation stage, and 46.0% for the preparation stage. The mean score of HACCP knowledge was positively correlated with understanding of HACCP program as well as the application. Also, the implementation of HACCP program was positively correlated with the understanding of HACCP.

• 한국식품조리과학회지
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• 제32권6호
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• pp.724-733
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• 2016

Purpose: This study was to evaluate the microbiological quality of salads in lunchbox's based on the holding time and temperature at convenience and franchise stores. Methods: Cabbage salad and crab meat salad were targeted for microbiological quality assessment. They were tested for aerobic plate counts, coliforms, Escherichia coli, Staphylococcus aureus and Enterobacteriaceae and assessment were performed by Korean Food Standards Codex. Results: In cabbage salad at convenience franchise store's at $5^{\circ}C$, the aerobic plate counts did not exceed the Korean Food Standards Codex. For cabbage salad stored at $25^{\circ}C$, the aerobic plate counts was 5.08 log CFU/g we hours after purchase, which exceeded the Korean Food Standards Codex. In case of cabbage salad in franchise store, the E. coli and S. aureus count exceeded Korean Food Standards Codex 3 hours after purchase. Microbiological analysis did not exceed the Korean Food Standards Codex at $5^{\circ}C$ in crab meat salad in convenience store. At $25^{\circ}C$, the aerobic plate count was detected at 4.45 log CFU/g after 32 hours, coliforms, E. coli, and S. aureus did not detect, but Enterobacteriaceae was found to be 2.34 log CFU/g after 9 hours in franchise store's crab salad. Coliforms was detected at 1.18 log CFU/g after 3 hours, and S. aureus was detected at 2.04 log CFU/g after 6 hours at $25^{\circ}C$ in the franchise store. The lunchbox' salad under cold storage ($5^{\circ}C$) generally meet the Korean Food Standards Codex. Conclusion: The results indicate an urgent need to implement proper management guidelines for the production of lunchbox foods to ensure microbiological safety, and to improve the shelf life from production to consumption.

• 한국화재소방학회논문지
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• 제30권4호
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• pp.73-81
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• 2016

정온전선은 평형 도체 사이에 반도전성 폴리머를 연속 압출 방식으로 충전시킨 후 양 도체 사이에 전기를 흐르게 함으로써 고분자에 의한 전열을 이용한 전기 발열체이다. 정온전선은 가격이 저렴하고 시공이 편리하기 때문에 겨울철 수배관의 동파방지용 열선으로 주로 사용되고 있다. 하지만 이러한 유용함에도 불구하고 구조적인 문제로 인하여 두 평형 도체의 절연이 파괴되는 경우에는 화재로 이어질 수도 있는 위험성이 존재하고 있다. 본 논문은 정온전선에 의한 화재현장을 조사하여 원인을 도출하는 방식으로 직접적인 원인을 추론하고자 하였으며, 결함수 분석을 통해 근본적인 문제를 파악해 보고자 하였다. 실제 냉동창고 화재현장을 조사하여 정온전선에 의한 화재원인을 추론한 결과 전선 말단 절연처리 결함에 의한 절연파괴인 것으로 판단되었다. 향후 이 결과는 안전활동 및 유사 화재원인조사 시에도 활용될 수 있을 것이다

• Journal of Biosystems Engineering
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• 제31권3호
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• pp.168-174
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• 2006

The purpose of this study is to develop the cold chain system by developing optimal phase change materials (PCM). There are some benefits from developing this system such as keeping freshness of agriculture products, saving energy, etc. The major results are as follows. To decide a latent heat material, the characteristics of water, sodium, polyacrylate, ethanol and N-tetradecane are analysed. Also, an insulating material is made by mixing water, nucleating agent and latent heat material, using cementing method. In addition, the sensitivity analysis for developed latent heat material($K_l,\;K_2,\;K_3$) is conducted. For $K_l,\;K_2,\;K_3$ which cans keep latent heat temperature, ranging from $0\;to\;5^{\circ}C,\;5\;to\;10^{\circ}C,\;10\;to\;15^{\circ}C$. it can keeps latent heat temperature at radiant heat (5, 12, $17^{\circ}C$) and transportation latent heat container both melting temperature and amount of latent heat of Kl are $-1.6{\pm}1.0^{\circ}C$, 326.51 J/g, respectively and freezing temperature and latent heat are $-7.98{\pm}1.5^{\circ}C$ and 174.18 J/g. and $K_2$ are $7.41{\pm}1.5^{\circ}C$, 89.80 J/g, respectively and freezing temperature and latent heat are $-2.14{\pm}1.5^{\circ}C$ and 83.90 J/g. and $K_3$ are $9.54{\pm}1.0^{\circ}C$, 145.42 J/g, respectively and freezing temperature and latent heat are $0.21{\pm}1.0^{\circ}C$ and 152.48 J/g.

• 한국동물위생학회지
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• 제36권4호
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• pp.291-296
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• 2013

The purpose of this study was to determine food safety practices and procedures based on Hazard Analysis Critical Control Point (HACCP) system and to suggest more effective method of HACCP implementation in meat packaging industry in Korea. We used the non-compliance rate of each evaluation item to compare the weak points of prerequisite requirements and HACCP. The prerequisite items related to facility, equipment, and tools showed inadequate level of requirements or unsanitary conditions for proper HACCP operation. A lack of understanding of sanitation standard operation procedures was identified as a fundamental barrier to HACCP implementation. High rate of non-compliance in HACCP items compared to prerequisite requirements signify that small businesses have potential difficulties of applying HACCP due to lack of technical expertise, financial resources for prerequisite requirements, and available personnel to prepare and operate HACCP plan. Also we suggest to revise and minimize current critical control points (CCPs). Time-temperature control of cold-storage rooms for carcasses and final products could be performed by control points of prerequisite requirements. As the occurrence frequency getting lower, metal detector should be replaced by intensified training of sanitary handling and safety procedure. This will be more effective and preventive measures against physical contaminants including metal particles. In conclusion, control point of prerequisite requirement may replace CCP in the plant with simple processing line and no heating process such as meat packaging industry.

• Applied Biological Chemistry
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• 제35권1호
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• pp.36-41
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• 1992

면실유, 옥배유 및 채종유의 산패도를 신속하고 재현성 있게 측정하고자 $60^{\circ}C$ 및 $70^{\circ}C$로 저장한 식용유의 pentanal과 hexanal을 headspace 가스크로마토그라피 방법으로 분석하였고, 그 결과를 관능검사 결과와 상관분석을 실시하였다. Headspace 가스크로마토그라피 방법에서 휘발성 산화생성물의 포집 및 용출은 cold trap-thermal desorption 방법으로 실시하였으며, GC 주입부에 들어가는 splitless mode glass liner insert에 Tenax GC를 충전하여 사용하였다. 23종의 휘발성 산화생성물이 gas chromatography 및 gas chromatography-mass spectrometry에 의하여 검출되었으며, 저장 기간에 따른 pentanal과 hexanal 함량 변화와 관능검사에 의한 산패취 측정 결과의 상관분석을 실시한 결과, pentana(PE), hexanal(HE) 및 log{PE) log(HE) $log(PE){\times}log(HE)$의 세 가지를 변수로 한 회귀식의 상관계수의 값이 각각 0.831, 0.866 및 0.896으로 다같이 높을 값을 보였다. 따라서 headspace 가스크로마토그라피를 이용하여 면실유, 옥배유 및 채종유의 휘발성 산화생성물 중 pentanal과 hexanal을 분석하면 각각의 식용유의 산패도를 객관적으로 평가할 수 있음을 알 수 있었다.

• 원예과학기술지
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• 제32권3호
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• pp.359-365
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• 2014

본 연구는 신고 배 저온 저장 중 발생하는 과피 흑변에 관여하는 주요 대사체를 untargeted GC-MS 그리고 targeted HPLC로 알아보고자 하였다. GC-MS 분석 결과 아미노산, 유기산, 당 관련 총 40개의 대사체를 정성할 수 있었고 건전과는 과피흑변과에 비해서 전반적으로 높은 대사체 함량을 보였다. 특히 serine, malic acid, succinic acid가 건전과에서 높게 나타난 반면 과피 흑변과에서는 threonine, fumaric acid, gluconic acid 함량이 높았다. 개개의 phenolic compounds 분석 결과 건전과에서 높은 phenolic compounds 함량을 보였다. 또한 항산화 능력과 깊은 관련이 있는 ascorbic acid가 과피 흑변과에서 낮게 나타났다. 이상의 결과로 보아 세포 내 비정상적인 호흡 및 에너지 대사과정, 항산화 능력 결여가 신고 배 과피 흑변에 관여하는 주요 대사 과정임을 확인할 수 있었다.