• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6759-6765
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• 2015

In this study, the effects of control strategies of night-purge control system on control characteristics and energy consumption for central cooling system in building are researched by simulation. The start time and set-point temperature for night-purge control with outdoor temperature changes and building cold storage performance are obtained. The system analysis modelling is done by using TRNSYS program package, and the control performances with suggested night-purge control method are compared with the existing control ones. As a result, the suggested night-purge control method shows maximum 16.8% and 28.6% energy saving in comparison with existing control method and conventional one without night-purge control, respectively.

• Journal of Biosystems Engineering
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• v.19 no.4
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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.

• Tunnel and Underground Space
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• v.26 no.1
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• pp.12-23
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• 2016

For a successful accomplishment of Carbon Capture Sequestration (CCS) projects, appropriate injection conditions should be designed and optimized for site specific geological conditions. In this study, we evaluated the effect of injection conditions such as injection temperature and injection rate on the geomechanical stability of CCS system in terms of TOUGH-FLAC simulator, which is one of the well-known T-H-M coupled analysis methods. The stability of the storage system was assessed by a shear slip potential of the pre-existing fractures both in a reservoir and caprock, expressed by mobilized friction angle and Mohr stress circle. We demonstrated that no tensile fracturing was induced even in the cold CO2 injection, where the injected CO2 temperature is much lower than that of the reservoir and tensile thermal stress is generated, but shear slip of the fractures in the reservoir may occur. We also conducted a scenario analysis by varying injected CO2 volume per unit time, and found out that it was when the injection rate was decreasing in a step-wise that showed the least potential of a shear slip.

• Korean journal of food and cookery science
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• v.15 no.6
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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.

• Korean journal of food and cookery science
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• v.32 no.6
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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.

• Fire Science and Engineering
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• v.30 no.4
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• pp.73-81
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• 2016

A self-regulating heating cable is an electrical heating element by flowing an electric current between parallel conductors filled with an extruded semi-conductive polymer. Self-regulating heating cables are used mainly for frost protection purposes because the construction is convenient and the price is low. On the other hand, structural problems with imperfections of the insulation can cause a fire despite their usefulness. This paper deduced a direct method to derive the cause by investigating the scene of a fire due to a self-regulating heating cable and analyzed the basic problem using fault tree analysis. In this paper, the actual fire scene was a cold storage warehouse, and fire investigation was conducted. After investigating the fire scene and fault tree analysis, the cause of the fire could be attributed to dielectric breakdown of the self-regulating heating cable. This paper could be utilized in the fire safety activities and similar fire investigations.

• Journal of Biosystems Engineering
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• v.31 no.3 s.116
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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.

• Korean Journal of Veterinary Service
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• v.36 no.4
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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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• v.35 no.1
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• pp.36-41
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• 1992

Several commercial cottonseed, corn and rapeseed oils were stored at $60^{\circ}C\;and\;70^{\circ}C$ with daily exposure of fluorescent light for 12 hours and evaluated their rancidity by headspace gas chromatographic analysis of pentanal and hexanal. The data of gas chromatographic analysis was compared with organoleptic flavor evaluation. For headspace gas chromatographic analysis, the volatile compounds were recovered by porous polymer trap and flushed into a fused silica capillary column at $250^{\circ}C$. Twenty-three GC peaks were identified on the basis of relative retention time of reference compounds and gas chromatography-mass spectrometry. The results showed that the contents of pentanal and hexanal were linearly increased during storage. A very simple linear relationship was found between organoleptic flavor scores and amounts of two volatile compounds with very high correlation coefficient. This results suggested the possible implication of pentanal and hexanal as an quality index for rancidity evaluation of cottonseed, corn and rapeseed oils.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.359-365
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• 2014

Oriental pear (Pyrus communis L. cv 'Niitaka') was stored at $0^{\circ}C$ for 5 months and major metabolites involved in blackening of the peel were analyzed by untargeted GC-MS and targeted HPLC methods. In this study, peels of sound and skin-blackened pears were analyzed and compared. Skin-blackened fruit was clearly characterized by a distinctive pattern in changes which included a decrease of malic acid, succinic acid, and ascorbic acid, while an increase of fumaric acid, threonine, and gluconic acid, which indicated both reduced metabolic activity and anti-oxidative capacity of the cells. Chlorogenic acid was a major phenolic compound and the peel of sound fruit showed high levels of free phenolic compounds compared than the peel of skin-blackened fruit which are believed to be related to oxidation of phenolics in skin-blackened tissue. The changes or profiling of major metabolites by targeted or untargeted analysis method could become a useful tool for understanding physiology, disorder mechanism, and identifying metabolic networks connecting primary and secondary metabolism in postharvest research.