• Journal of the Korean Institute of Gas
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• v.21 no.5
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• pp.83-88
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• 2017

The purpose of this paper is to study for a failure examples producing in electronic control air conditioner in vehicle. The first example, it looked for the repetitive fuse cutting phenomenon that the diode using for a surge voltage prevention of inner A/C relay damaged because of no absorbing the surge voltage by short of diode when the A/C is off. The second example, it knew the icing phenomenon of evaporator that the A/C ECU didn't control the A/C because of inner cutting of fin thermo sensor. The third example, it verified the operation trouble phenomenon because of the A/C switch and for sensor burned in flames by short phenom enon when the sheath of the cable has peeled off. Therefore, the driver have to manage the optimism system of a car by thoroughgoing inspection and improvement the failure phenomenon.

• Applied Biological Chemistry
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• v.45 no.4
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• pp.212-217
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• 2002

We purified polyphenols from persimmon leaf and tested their biological activity. The 60% acetone extract was lyophilized and applied to test enzyme inhibition of glucosyltransferase and tyrosinase. GTase was 82.4% inhibited at $1.8{\times}10^{-1}$ mg/ml and tyrosinase 21.7% inhibited at 0.8 mg/ml. The acetone extract was fractionated into F-1, 2, 3, 4, 5 by Sephadex Q-50 gel filtration and the fraction-1 and 2 showed higher enzyme inhibition activity than the other fractions. To the Proteinase K treatment and autoclaving of the two fractions had no effect on the enzyme activity, but these results suggested that active fraction was not protein but phenol ring completed compounds. By Sephadex LH-20, MCI-gel and Bondapak $C_{18}$ column chromatographies, compouds 1, 2, 3 and 4 from F-1 fraction, compounds 5 and 6 from F-2 fraction and compounds 7 , 8 from F-3 fraction were purified and re-crystallized. The purified compounds was assumed to be condensed tannins of frame flavan-3-ol frame on the basis of color reagent reaction and to be a mixture of monomer, dimer and trimer according to TLC analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.525-531
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• 2018

This paper proposes a bi-component dye, including the unripe fruit of Diospyros kaki THUNB and Ecklonia cava, to substitute for traditional persimmon dyeing because fabrics dyed with persimmon juice become stiffer and natural persimmon is insufficient for dyeing. This study examined the color difference and fabric stiffness depending on the ratio of Ecklonia cava for in a one-bath dye solution with Diospyros kaki THUNB and showed that 6% of Ecklonia cava in the bi-component dye was the optimum for decreasing the fabric stiffness. Based on these results, a bi-component dye constituting of 94% Diospyros kaki THUNB and 6% Ecklonia cava was prepared. The particle size was found to be smaller than both single dyes and it maintained a similar amount of Catechin to Diospyros kaki THUNB dye. Finally, cotton fabric dyed with a bi-component dye was much improved in terms of the fabric hand and the surface color was similar to that of the traditional persimmon-dyed fabric. These results could help to develop the natural persimmon dyeing industry.

• Geophysics and Geophysical Exploration
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• v.8 no.1
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• pp.67-72
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• 2005

To investigate the feasibility of a new concept of storing Liquefied Natural Gas (LNG) in a lined hard rock cavern, and to develop essential technologies for constructing underground LNG storage facilities, a small pilot plant storing liquid nitrogen (LN2) has been constructed at the Korea Institute of Geoscience and Mineral Resources (KIGAM). The LN2 stored in the cavern will subject the host rock around the cavern to very low temperatures, which is expected to cause the development of an ice ring and the change of ground condition around the storage cavern. To investigate and monitor changes in ground conditions at this pilot plant site, geophysical, hydrogeological, and rock mechanical investigations were carried out. In particular, geophysical methods including borehole radar and three-dimensional (3D) resistivity surveys were used to identify and monitor the development of an ice ring, and other possible changes in ground conditions resulting from the very low temperature of LN2 in the storage tank. We acquired 3D resistivity data before and after storing the LN2, and the results were compared. From the 3D images obtained during the three phases of the resistivity monitoring survey, we delineated zones of distinct resistivity changes that are closely related to the storage of LN2. In these results, we observed a decrease in resistivity at the eastern part of the storage cavern. Comparing the hydrogeological data and Joint patterns around the storage cavern, we interpret this change in resistivity to result from changes in the groundwater flow pattern. Freezing of the host rock by the very low temperature of LN2 causes a drastic change in the hydrogeological conditions and groundwater flow patterns in this pilot plant.

• Journal of Food Hygiene and Safety
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• v.29 no.3
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• pp.202-206
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• 2014

In this study, the bacteriological survey was examined on ice creams at manufacturing factories in Korea during the summer season of 2011. The nineteen selected among 166 samples by preliminary test were collected from 11 different manufacturing factories in four major manufacturers in May 2011. Samples from ice milk, ice creams, sherbets, and non milk fat ice creams were tested for the total aerobic bacteria, coliform bacteria, and five food borne pathogens, respectively. The results showed that the coliforms including E. coli O157:H7, Salmonella spp., Staphylococcus aureus, Clostridium perfringens, and Listeria monocytogenes were not detected on all the ice creams. The total aerobic bacteria of the packed samples examined ranged between $2.5{\times}10^3$ and $5.5{\times}10^5cfu/g$. One ice cream, two sherbets, and four ice milk samples exceeded the acceptable limits of total aerobic bacteria according to the Korean standards for ice cream ($1.0{\times}10^5cfu/g$) and others ($5.0{\times}10^4cfu/g$). The levels of these microorganisms from ice creams were higher in three original equipment manufacturers than seven self-manufacturers. Three of ten ice creams (30.0%), three of six ice milks (50.0%), and one of two sherbets (50%) exceeded the acceptable limits of total aerobic bacteria, respectively. The personnel hygiene procedures with chocolate and vanilla chip addition from the manufacturing process were the main sources of the microbial contamination of stick-bar type ice creams when being produced in a factory. Improvement of the hazard analysis critical control points (HACCP) system should be introduced into the ice cream factory to improve the microbial quality of the ice cream products in Korea.

• Journal of the Korean association of regional geographers
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• v.19 no.2
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• pp.234-245
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• 2013

In order to examine the amount and rate of soil erosion on Ridge Traversing Trail in Jirisan National Park, a cross-sectional area of hiking trail were monitored at 16 sites in Nogodan - Samdobong section from November 2011 to April 2012. Although all sites demonstrates an enlarged cross-section of trail, the amount of soil erosion varies from site to site: 54.9 to $908.8cm^2$. It suggests that the erosional rate ranges from $0.1cm^2/day$ to $1.72cm^2/day$. The erosional amount is also varied with a trail type: $109.3cm^2$ for a shallow gully-like trail to $573.2cm^2$ for a unilateral trail. However, the cross-sectional change is larger on a sidewall than a tread irrespective of a trail type. The erosional amounts of November to April are smaller than that of May to October. In particular, the erosional amount of November 2011 to April 2012 is smaller than the depositional amount, implying a reduced cross-section of trail. Pipkrake action puts loose soil particles on a sidewall on March and April, and then rainwash due to a heavy rainfall takes them away after May. It seems to be the most predominant erosional process in Ridge Traversing Trail. A sidewall facing north shows a larger amount of erosion than a sidewall facing south. It also implies a difference in the development of a pipkrake according to an aspect. The small amount of erosion and cross-sectional decrease, which is usually observed on April, results from the combined effect of frost heaving, pipkrake action, a small rainfall and a temporary suspension of trampling. It is necessary to establish the monitoring system of trail erosion in terms of the management of hiking trail in a mountain national park.

• Korean journal of applied entomology
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• v.61 no.3
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• pp.409-422
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• 2022

Two dominant thrips in hot pepper (Capsicum annuum) cultivating in greenhouses are Frankliniella occidentalis and F. intonsa in Korea. This study investigated their overwintering physiology. These two thrips were freeze-susceptible and suppressed the body freezing temperature by lowering supercooling point (SCP) down to -15~-27℃. However, these SCPs varied among species and developmental stages. SCPs of F. occidentalis were -25.7±0.5℃ for adults, -17.2±0.3℃ for pupae, and -15.0±0.4℃ for larvae. SCPs of F. intonsa were -24.0±1.0℃ for adults, -27.0±0.5℃ for pupae, -17.2±0.8℃ for larvae. Cold injuries of both species occurred at low temperature treatments above SCPs. Thrips mortality increased as the treatment temperature decreased and its exposure period increased. F. occidentalis exhibited higher cold tolerance than F. intonsa. In both species, adults were more cold-tolerant than larvae. Two thrips species exhibited a rapid cold hardening because a pre-exposure to 0℃ for 2 h significantly enhanced the cold tolerance to a lethal cold temperature treatment at -10℃ for 2 h. In addition, a sequential exposure of the thrips to decreasing temperatures made them to be acclimated to low temperatures. To investigate the overwintering sites of the two species, winter monitoring of the thrips was performed at the greenhouses. During winter season (November~February), adults of the two species were not captured in outside of the greenhouses. However, F. occidentalis adults were captured to the traps and observed in weeds within the greenhouses. F. occidentalis adults were also emerged from soil samples obtained from the greenhouses during the winter season. F. intonsa adults did not come out from the soil samples at November and December, but emerged from the soil samples obtained after January. To determine the adult emergence due to diapause development, two thrips species were reared under different photoperiods. Adult development occurred in all photoperiod treatments in F. occidentalis, but did not in F. intonsa especially under short periods. Tomato spotted wilt virus, which is transmitted by these two species, was detected in the weeds infested by the thrips during the winter season. These results suggest that F. occidentalis develops on weeds in the greenhouses while F. intonsa undergoes a diapause in the soil during winter.