• Journal of Korean Society of societal Security
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• v.3 no.1
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• pp.43-50
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• 2010

Sliding accidents on the road have a high percentage by road freezing, especially, they often have appeared at bridges and Tunnel of freezing areas. Thus, the stability of road operations is enhanced by preventing partial freezing phenomenon. According to the geothermal snow melting system analysis, a pattern of thermal conductivity is found out; pavement materials of concrete and asphalt where the system is buried. The heat transfer simulation is essential when the geothermal snow melting system is applied according to heating exchanger pipe placed in the lower pavements. The model tests are conducted on low temperature in freezer using the manufactured test model which is equal to pavement materials. Many variables are discovered from numerical analyses under the same conditions with model test.

• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.298-302
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• 1995

This study was performed to know the availability of low erucic acid rapeseed oil (LEAR oil) for vegetable oil in commercial mayonnaise preparation. Mixed oils (blended soybean oil with LEAR oil) were prepared and mayonnaises were prepared with these oils and then compared the quality characteristics of these samples. The oxidative stability of vegetable oil with Rancimat test showed that LEAR oil was higher stability than soybean oil, and became higher with increase of LEAR oil ratio. Quality characteristics of mayonnaises with these oils showed that mayonnaise with mixed oils was preferred to that with LEAR oil itself. Furthermore, the quality characteristics of mayonnaises with mixed oils of soybean oil $(20{\sim}60%)$ plus LEAR oil $(80{\sim}40%)$ were better than those of mayonnaise with soybean oil solely.

• Biomedical Science Letters
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• v.5 no.2
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• pp.167-179
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• 1999

There are considerable interests in bat biology for investigating hibernation mechanism, in special regard to a hypothesis that the entry into hibernation is closely related with epileptic fit (petit mal) accompanying falling of body temperature, which is characterized by 3 spikes and wave/sec formation in electroencephalograph (EEG). This study was designed in order to examine physiological parameters (body temperature, heart rate, electroencephalograph and brain mapping) during normal patterns of the entry into hibernation and the hibernation period, and to observe effects of epileptogenic agents such as THC, Metrazol, and ILS on the physiological parameters. Based on the experimental results the entry into some hibernation seems to be related with epileptic fit, and therefore it is deduced that north temperate bats and the hamsters might be induced into hibernation by epileptogenic factors (pentylenetetrazol, THC and ILS etc) accompanying falling of body temperature and unique EEG and brain mapping.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.5
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• pp.577-582
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• 2015

This paper is the fundamental study for the application of cold storage system to the transportation equipment by sea and land. This numerical study presents the solid-liquid phase change phenomenon of calcium chloride solution of 30wt %. The governing equations are 1-dimensional unsteady state heat transfer equations of $1^{st}$ order partial differential equations. This type of latent heat storage material is often usable in fishery vessel for controlling the temperature of container with constant condition. The governing equation was discretized with finite difference method and the program was composed with Mathcad program. The main parameters of this solution were the initial temperature of heat storage material, ambient temperature of cold air and the velocity of cold air. The data of boundary layer thickness becomes thin with the increasing of cold air flowing velocity and also the heat storage completion time become shorten.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.10
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• pp.883-890
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• 2005

In this study, 2 pure hydrocarbon refrigerants of R1270 (Propylene) and R290 (Propane) and 3 binary mixtures composed of R1270, R29O and R152a were tested in a refrigerating bench tester with a scroll compressor in an attempt to substitute R502 used in most of the low temperature applications. The test bench provided 3\sim3.5$ kW capacity and water and water/glycol mixture were employed as the secondary heat transfer fluids. All tests were conducted under the same external conditions resulting in the average saturation temperatures of -28 and $45^{\circ}C$ in the evaporator and condenser, respectively. Test results showed that all refrigerants tested had $9.6\sim18.7\%$ higher capacity and $17.1\sim27.3\%$ higher COP than R502. The compressor discharge temperature of R1270 was similar to that of R502 while those of all other refrigerants were $23.7\sim27.9\%$ lower than that of R502. For all alternative refrigerants, the amount of charge was reduced up to $60\%$ as compared to R502. Overall, these alternative refrigerants offer better system performance and reliability than R502 and can be used as long term substitutes for R502 due to their excellent environmental properties.

• Applied Biological Chemistry
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• v.13 no.3
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• pp.207-218
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• 1970

Studies were carried out to develope the most economical and practical methods of packaging and preservation of kimchi, so commercialization of kimchi manufacture could proceed rapidly. The results obtained may be summarized as following. (1) It is generally established that the acceptable range of lactic acid content of kimchi is between 0.4% and 0.75%. Based on sensory evaluation, kimchi having lactic acid content below 0.4% and above 0.75% was not edible, and the time of optimum taste corresponded to the vicinity of 0.5% of lactic acid content. For the refrigeration storage with or without preservatives, the packaging kimchi in plastic film must be done at the lactic acid content of 0.45%, for lactic acid fermentation will continue slowly after the packaging. However, for the heat sterilized kimchi the packaging should be done at the 0.5% of lactic acid content for the best because lactic acid fermentation is completely stopped after the packaging. (2) Polyethylene, polypropylene, and polycello were chosen as suitable packaging materials. Polyethylene is cheapest among them but kimchi packaged in this film was damaged frequently in handling process and gave off kimchi flavor. On the other hand polypropylene also gave off kimchi flavor, but its higher mechanical strength gave better protection to kimchi and it had superior display effect due to the transparancy. Therefore polypropylene made much better packaging material. Polycello proved to be the best packaging material from the standpoint of physical characteristics but its price is higher than that of other plastic films. To be effective, the thickness of plastic films for packaging kimchi must exceed 0.08mm. (3) Keeping property of kimchi appeared to be excellent by means of freezing. However, by the time the frozen kimchi was thawed out at room temperature, moisture loss due to drip was extensive, rendering the kimchi too stringy. (4) Preservation of kimchi at refrigerated temperatures proved to be the best method and under the refrigerated condition the kimchi remained fresh as long as 3 months. The best results were obtained when kimchi was held at $0^{\circ}C$. (5) In general, preservatives alone were not too elective in preserving kimchi. Among them potassium sorbate appeared to be most effective with the four fold extension of self-life at $20^{\circ}C$ and two fold extension at $30^{\circ}C$. (6) In heat sterilization the thickness of packaged kimchi product had a geat effect upon the rate of heat penetration. When the thickness ranged from 1.5 to 1.8cm, the kimchi in such package could be sterilized at $65^{\circ}C$ for 20 minutes. Kimchi so heat treated could be kept at room temperature as long as one month without apparent changes in quality. (7) Among combination methods, preservation at refrigerated and heat sterilization could be favorably combined. When kimchi was stored at $4^{\circ}C$ after being sterilized at $65^{\circ}C$ for 20 minutes, it was possible to preserve the kimchi for more than 4 months.

• Korean Journal of Weed Science
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• v.16 no.2
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• pp.114-121
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• 1996

This study was conducted to investigate seed germination, seedling growth, and responses to herbicides of Bidens tripartita L. When the field-collected seeds were stored under a dry-room temperature, dry-low temperature, wet-low temperature, or dry-high temperature condition, no seeds were germinated in a growth chamber with 14 hr photoperiod up to 35 days after the storage. Exceptionally, however, some seeds stored under a wet-room temperature condition were germinated after 25 days of the storage. This might be due to the fact that the seed coats were damaged by fungi which developed during the storage. Seeds stored under a wet-low temperature condition (stratification) began to be germinated after 3 months of the storage and the germination rate increased with a prolonged stratification. Almost all seeds were germinated after 9 months of the stratification. These results suggest that the dormancy of B. tripartita L. seeds relate to the seed coat and thus several attempts were made to induce seed germination through damaging or weakening the seed coat. Freezing($-20^{\circ}C$), drying($100^{\circ}C$), or swelling($40^{\circ}C$) of the seeds was not effective to induce the germination. Treatments of concentrated sulfuric acid, $KNO_3$, or gibberellin to the seeds had no effect on inducing the germination. However, ethrel had a stimulatory effect on the germination of the seeds with an optimum concentration of 250ppm. A seed cutting was also effective to induce the germination, but seedlings from the seeds had cutted cotyledons. Germination of the stratified seeds varied with the temperature condition to which they were subjected, but not with light. The germination rate was the highest at 35 - $40^{\circ}C$. Although the seeds were not able to germinate under a submerged condition, seedlings after 2-leaf-stage exhibited better growth under a submerged or a subirrigated condition than under an upland condition. Among the herbicides tested, pyrazosulfuton-ethyl, linuron, and bentazone were found to be effective for controlling B. tripartita L., having more herbicidal effect with an earlier application.

• Applied Biological Chemistry
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• v.38 no.2
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• pp.141-146
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• 1995

Changes of physicochemical properties of citron juice prepared by two different extraction methods, rotary-crushing and belt-pressing method, were investigated during the storage at $5^{\circ}C$ and $-20^{\circ}C$. Temperature drop of citron juice extracted by belt-pressing method was faster than that of citron juice prepared by rotary-crushing method and its freezing point was $0.8{\sim}0.9^{\circ}C$. During the storage, pH of stored citron juice with rotary-crushing method was increased up to 3.5 after 6 months storage while that of citron juice extracted by belt-pressing method was not changed significantly during the same storage time. Acidity of rotary-crushed citron juice was reduced a little more than that of belt-pressed citron juice during the storage. However, changes of soluble solid content were influenced largely by the storage temperature than by the extraction method. Contents of formol nitrogen and vitamin C were reduced remarkably in all of stored citron juice and $92{\sim}82%$ of farmol nitrogen and $72{\sim}43%$ of vitamin C were remained after 6 months of storage. Among the changes of color value, L values were reduced in the whole stored citron juice and a and b value had a different change pattern respectively according to the extraction and storage temperature. Changes in the content of both amino acid and fatty acid compositions was also observed after same storage period. Especially, in the case of change of fatty acid composition, content of linoleic acid and linolenic acid were reduced after 6 months storage, while those of palmitic acid, stearic acid and oleic acid were increased.

• Journal of fish pathology
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• v.23 no.1
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• pp.123-129
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• 2010

The infestation status of anisakid type larvae was investigated in migrating chum salmon (Oncorhynchus keta), with different condition (captured area, sex, body portion) during 2006~2008. The mean infection number of anisakid larvae per individual female and male fish captured from Namdae river was $98{\pm}27$, $103{\pm}27$, respectively. The mean infection number of anisakid larvae per individual female and male fish captured from the coastal area of Yangyang was $63{\pm}18$ and $108{\pm}17$, respectively. The anisakid larvae were mainly found in abdominal muscles (85%) but only a little in the visceral portion. Two types of anisakid larvae (A. simplex, Contracaecum type) were identified but other anisakid larvae were not detected. To investigate the effect of storing temperature on the viability of anisakid larvae, the section of abdominal muscle were stored at different temperature (room temperature, $4^{\circ}C$, $-20^{\circ}C$, $-80^{\circ}C$). As a result, it was necessary to store at $-20^{\circ}C$ for more than 6 hrs to kill the larvae. The present results revealed that chum salmon caught in Korea are heavily infected with anisakid larvae, mainly in the abdominal muscle, and A. simplex was dominantly found in this study.

• Korean Journal of Weed Science
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• v.7 no.3
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• pp.257-264
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• 1987

Effect of various physical and chemical treatments on dark germination of Oenothera lamarckiana seeds were primarily investigated to find out factors affecting germination. Germination of seeds which did not germinate in the constant temperature and darkness was induced by several physical treatments such as sonification, wetting and drying, freezing and thawing, and removal of seed coat. Pretreatment of chilling ($4^{\circ}C$), freezing ($-10^{\circ}C$) and incubation at high temperature ($80^{\circ}C$) induced dark germination of seeds which did not germinate in the constant temperature ranges of 15 to $40^{\circ}C$ under darkness. Alternating temperature also had a stimulatory effect on dark germination of Oenothera lamarckiana seeds. Sensing of seeds to alternating temperature appeared to be completed during the first two days after imbibition. The minimum difference of temperature required for dark germination was $5^{\circ}C$ in the range of $15-25^{\circ}C$. A thiourea (1.0%) treatment induced dark germination, but GA, IAA, BA and Ethrel failed to do so.