• Journal of the Korean Society for Precision Engineering
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• v.19 no.10
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• pp.221-226
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• 2002

As environmental restriction has continuously become more strict, machining technology has emphasized on development of environment-friendly technologies. In cutting technology, it has been well recognized that cutting fluids might have undesirable effects on workers health and working environment and, hence, recently there have been numerous attempts to minimize harmful effects of cutting fluids on environments. To minimize the use of cutting fluids in machining, conventional cutting fluids have been replaced with the technologies of pressurized cold air and minimum quantity lubrication (MQL). Compared with milling, turning is continuous cutting process, where tools are continuously heated up and lack of lubricity could lead to tool wear and deteriorated surface roughness. In this work, it has been investigated how tool wear and surface roughness could be affected by cutting conditions, supply and cooling methods. The experimental results show that MQL technology is able to minimize conventional cutting fluids.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.3
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• pp.134-141
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• 2017

The purpose of this study was to analyze physiological changes via a cold air reaction experiment to generate basic data that are useful for the development of an automobile active air conditioning system to prevent drowsiness. The $CO_2$ concentration causing drowsiness in vehicle operation was kept below a certain level. Air was blown to the driver's face by using an indoor air cooling apparatus. Sleepiness and the arousal state of the driver in cold wind were measured by physiological signals. It was evident in the EEG that alpha waves decreased and beta waves increased, caused by cold air stimulation. The ${\alpha}/{\beta}$ ratio was reduced by about 52.9% and an alert state confirmed. In the electrocardiogram analysis, the efficiency of cold air stimulation was confirmed by the mean heart rate interval change. The R-R interval had a delay time of about one minute compared to the EEG response. The findings confirmed an arousal effect from sleepiness due to cold air stimulation.

• Food Science and Preservation
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• v.13 no.3
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• pp.337-343
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• 2006

This study was conducted to develop naengmyon added with persimmon leaf powder. To find out the proper mixing ratio, physicochemical properties were investigated. There was a little difference in water binding capacity between control and naengmyon added with persimmon leaf powder. Amylogram showed that initial pasting temperature and peak point value were increased as increment of adding amount of persimmon leaf powder. After cooking, the weight of a naengmyon was increased but cooking loss and turbidity were decreased with increment of persimmon leaf powder. At a glance of color difference values, there was a distinctive boundary near at 6%. But similar at over 6% as increasing adding amount of persimon leaf powder texture characteristics such as hardness, adhesiveness, cohesiveness, springness and gumminess were declined. From overall experimental result, the proper mixing ratio of persimmon leaf powder for naengmyon was 4%.

• Journal of Life Science
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• v.12 no.5
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• pp.535-543
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• 2002

To investigate the possibility of processing semi-dried jellyfish and to examine its keeping quality, the factors such as moisture content, pH, volatile basic nitrogen (VBN), viable cell counts, color value and texture were analyzed. For processing of the semi-dried product, optimum conditions of drying temperature and drying time were $25^{\circ}C$ and 90min, respectively, under 60 $\pm$ 5% of relative humidity and 2 m/sec of air blast speed. The shelf-life of the products, vacuum-packing method in nylon/polyethylene/linear low density polyethylene (0.015/0.045/0.040 mm) laminated film bag was at least 6 weeks during storage at 4$^{\circ}C$, while that of air packaged one was at least 4 weeks. In case of 2$0^{\circ}C$ storage the shelf-life of the products was at least 3 weeks in both air and vacuum packaged ones.

• Journal of Life Science
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• v.9 no.1
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• pp.44-49
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• 1999

A study was conducted to investigate the possibility of processing seasoned and semi-dried right-eyed flounder (Pseudopleuronects herzensteini) and to examine its quality during storage at $\pm$$3^{\circ}C$ by analyzing the factors such as moisture content, pH, volatile basic nitrogen (VBN), viable cell count and peroxide value (POV). For processing of the seasoned and semi-dried product, optimum conditions of drying temperature and drying time were $20^{\circ}C$ and 4 hrs, respectively, under 50$\pm$5$\%$ of relative humidity and 2 m/sec of air blast speed. The shelf-lives of the products by vacuum-packaging method in nylon/polyethylene/linear low density polyethylene (0.015/0.045/0.040 mm) laminated film bag were 35 and 16 days during storage at $-3^{\circ}C$ and $3^{\circ}C$, respectively.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.925-931
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• 1997

An attempt was made in this study to investigate the possibility of processing seasoned and semi-dried horse mackerel (Tracharus japonnicus) and to examine its keeping quality, by analyzing the factors such as water content, pH, volatile basic nitrogen, viable cell count, peroxide value, color value and sensory evaluation. For processing of the seasoned and semi-dried product, optimum conditions of drying temperature and drying time were $20^{\circ}C$ and 4 hr, respectively, under $50{\pm}5%$ of relative humidity and 2 m/sec of air blast speed. The shelf-life of the products, vacuum-packaging method in nylon/polyethylene/linear low density polyethylene $(0.015/0.045/0.04\;{\mu}m)$ film bag, was 42 days during storage at $-3{\pm}0.5^{\circ}C$, while that of unpackaged one was only 28 days.

• Journal of Power System Engineering
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• v.21 no.4
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• pp.62-69
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• 2017

Because the moist foods like anchovy were appeared lower quality by hot air that occurred the lipid oxidation, the drying system by using the cold air has been used widely. This study has been carried out on the performance improvement according to arrangement angle of baffle and location of air duct in the cold air dryer. The main parameters in this study are the arrangement angles which are without, $0^{\circ}$, $10^{\circ}$, $20^{\circ}$, $30^{\circ}$ and $40^{\circ}$, and the locations of air duct are without, front, center and back. For this study we have conducted the numerical analysis method using fluent in order to obtain the optimal condition of the drying performance. As the arrangement angle of baffle is increased, the relative humidity is proportionally decreased, the value at $40^{\circ}$ is 42.2% that indicate the reduction of about 4% than without it. After the air duct was installed, the decreased relative humidity is showed within 1%, therefore, the effect of air duct for improving the dry capacity is more large than the arrangement angle of baffle. Finally, we have obtained the optimal conditions that the arrangement angle is $40^{\circ}$ with the air duct for a cold air dryer.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.3
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• pp.179-183
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• 2000

This study was conducted to examine the changes of contents of ATP related compounds during drying of large anchovy and storage of dried large anchovy (DLA) according to storage temperature and package method. The total content of ATP related compounds of raw large anchovy was $36.0{\mu}mole/g$ and the major ATP related compounds were consisted of IMP and hypoxanthine. The IMP content of DLA was the highest in $20^{\circ}C$ cold-air drying, and the breakdown of IMP was progressed rapidly in $60^{\circ}C$ air drying, followed by $40^{\circ}C$ air drying, sun drying, and $20^{\circ}C$ cold-air drying. During storage of DLA, ATP was not detected while ADP and AMP was detected in a very small amount, and the changes of ATP related compounds were coincided with the changes of contents of IMP, inosine and hypoxanthine. The changes of ATP related compounds with different package method did not show distinct differences, while with different storage temperature showed clear difference. The content of IMP was over $8.88{\mu}mole/g$ on 60 days at $-20^{\circ}C$, while were over $0.83 {\mu}mole/g$ and$ 0.202 {\mu}mole/g$ on 16 days at$ 5^{\circ}C$ and$ 25^{\circ}C$, respectively. These results suggest that the breakdown of IMP depends on storage temperature and frozen storage affects good quality of DLA during storage.

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.468-474
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• 1993

A dehydrating sheet comprises polymeric water absorber. which are packed in a semipermeable cellophane film bag allowing selective permeation of water. This sheet dehydration is quite different from conventional drying method such as sun drying, hot-air blast drying and cold air blast drying in a sense that samples are dried without heat treatment. As a part of the studies to develope a new processing method for effective utilization of dark muscle fishes, the preparation of a good quality salted and semi-dried mackerel by the dehydrating sheet was attempted. The dehydration time for preparation of a salted and semi-dried mackerels containing approximately equal moisture content were revealed $180{\sim}510min$ in conventional drying method and $90{\sim}160min$ in this sheet dehydration, respectively. The moisture and histamine contents of those salted and semi-dried mackerels were $59.4{\sim}62.4%$ and $2.5{\sim}3.6 mg/100g$, respectively. The changes in peroxide value, fatty acid composition, brown pigment formation, myofibrillar protein solubility and Ca-ATPase activity during processing of the salted and semi-dried mackerel prepared by the sheet dehydration were more lower than those of products prepared by conventional drying methods. Therefore, these result showed that the quality of a salted and semi-dried mackerel prepared by the sheet dehydration was imperial to that of those products by conventional drying method.

• Korean Journal of Environment and Ecology
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• v.27 no.3
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• pp.357-368
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• 2013

This study was carried out to classify and describe the vegetation of algific talus in Korea by methods of the ZM school of Phytosociology. A part of slope or a hollow at the foot of talus in which cool air exhausts from underground through gaps of accumulated rock debris is called algific talus. From the sixty three stands obtained, the following two community and their four subcommunity were recognized: A. Quercus variabilis - Cystopteris fragilis com. B. Quercus mongolica - Betula schmidtii com. B-1. Quercus serrata - Urtica angustifolia subcom. B-2. Sorbus commixta - Spiraea chamaedryfolia subcom. B-3. Zabelia biflora - Astilboides tabularis subcom. B-4. Typical subcom. A. Quercus variabilis - Cystopteris fragilis com.. As a result of DCCA ordination, Quercus variabilis - Cystopteris fragilis com. has Quercus variabilis, Ligustrum var. obtusifolium, Zelkova serrata, Viburnum carlesii etc. as differential species, which showed the higher correlation with area of high Warmth index (WI) and precipitation than Quercus mongolica - Betula schmidtii com. has Quercus mongolica, Sorbaria var. sorbifolia, Magnolia sieboldii, Acer pseudosieboldianum, Rosa acicularis etc. as differential species. Sorbus commixta - Spiraea chamaedryfolia subcom. has Spiraea chamaedryfolia, Sorbus commixta, Rosa koreana, Vaccinium var. hirtum, Acer tegmentosum, Dryopteris expansa, Abies holophylla etc. as differential species. and Typical subcom in Quercus mongolica - Betula schmidtii com. were distributed in higher altitude and precipitation area than others. Zabelia biflora - Astilboides tabularis subcom. has Spiraea chinensis, Zabelia biflora, Astilboides tabularis, Gymnocarpium jessoense, Saussurea mongolica, Larix kaempferi etc. as differential species, which was distributed in area with high amounts of sunlight exposure by human activities.