• Journal of the Society of Disaster Information
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• v.19 no.2
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• pp.262-269
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• 2023

Purpose: In this study,fire-resistance test were executed to evaluate the effectiveness of the fireproof panel attached to the PSC slab in tunnel. Method: For the fire resistance test, the RWS curve was applied and the furnace of the KICT was used. Result: As a result of the experiment, the maximum temperature measured on the concrete surface of the PSC slab with the fireproof panel was 321.8℃, which was lower than the damage limit temperature of 380℃ for concrete. Also, at the t=25mm, the maximum temperature was 35.2℃, which was lower than the damage temperature of steel, 250℃. The use of precast fire resistance panel(t=30mm) improves fire resistance of PSC structures. Conclusion: As a result of the test, a reinforcement method for attached a fireproof panel in case of fire in a tunnel or an underground roadway is provided to protect a structure from fire. In the future, it is necessary to perform the static performance test of the slab to which the fireproof panel is attached, and to confirm the adhesion performance of the fireproof panel by performing the pull-off test and the fatigue test.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.84-84
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• 2022

The limit of crop cultivation is moving northward due to the temperature rise by climate change. There is a problem with crop growth if early sowing is performed at a time when the temperature is low. It is difficult to secure crop productivity and cultivation stability due to the low temperature and short cultivation period. Therefore, this study was conducted to analyze the change in growth characteristics and yield of corn for grain when early sowing is performed in central region of South Korea. This experiment was conducted at experimental field of Suwon in 2021. Three varieties of corn for grain such as Kwangpyeongok, Sinhwangok, and Hwangdaok were sown at intervals of 5 days from 20 March to 15 April. The planting density at this time was sown with a row interval of 70 cm and a plant interval of 25 cm. Nitrogen, phosphoric acid, and potassium fertilizers were applied at 17.4 kg, 3.0 kg, and 6.9 kg per 10a, respectively. Phosphoric acid and potassium fertilizers were all applied before sowing and nitrogen fertilizer was applied 50% before sowing and 50% in the fifth leaf period. The corn growth characteristics and yield components were investigated. The seedling establishment rate by sowing date was in the range of 68.5~88.5%, and it showed a difference depending on the variety. The range of days from sowing to tassel and silk emergence by sowing date was 79.9~98.4 and 81.0~98.9 days, respectively. As the sowing date was delayed, the days from sowing to tassel and silk emergence decreased. The growth characteristics and yield of corn by sowing date are as follows. Plant height was the highest at 241.3 cm at the sowing on 25 March, and Stalk diameter was the thickest at 25.6 mm at the sowing on 31 March. The fresh weight per plant was the highest at 728 g at the sowing on 25 March, and the dry weight per plant was the highest at 185 g at the sowing on 31 March. Corn growth characteristics did not show a certain trend depending on the sowing date, and corn growth was more vigorous at the sowing on March 25 and 31 than the others. In the case of ear weight, it was the heaviest with 344 g at the sowing on 25 March, and filled ear length ratio showed a tendency to decrease as the sowing time was delayed. The weight of 100 grains and grain yield per 10a of maize were the highest at 36.0g and 878.7kg/10a, respectively at the sowing on 25 March. Although the growth and yield of corn for grain were good during early sowing in the central region of South Korea, it is necessary to investigate the limit temperature for early sowing of corn by examining the annual variation according to weather conditions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.4018-4024
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• 2012

The purpose of this study was to application in the HACCP(Hazard Analysis Critical control) system of fried kimchi soup. The establishment of Critical limit during sterilization processing was measured by sterilization temperature, sterilization time, sensory test, storage test and pH change in storage for 30 days (May 1~30, 2012). Before sterilization, general bacteria, coliform and thermophile bacteria were detected to be $6.00{\times}10^5\;CFU/m{\ell}$, $7.50{\times}10^2\;CFU/m{\ell}$ and $2.75{\times}10^2\;CFU/m{\ell}$, respectively. In contrast, all microbial was not detected after sterilization($90{\pm}5^{\circ}C$, $22{\pm}5$ mins). The sensory test was decided as the most delicious kimchi according to $90{\pm}5^{\circ}C$, $22{\pm}5min$. In conclusion, the sterilization process of fried kimchi soup would be a great alternative to prevention, decreasing and removing of harmful microorganism, such as general bacteria, coliform and thermoduric bacteria etc. Therefore, the critical limit of sterilization temperature and time for quality control and biosafety was established at $90{\pm}5^{\circ}C$, $22{\pm}5$ mins. And it suggested that HACCP plan was necessary for monitoring method, monitoring cycle, problem solving method, education, training and record management during sterilization processing.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.5
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• pp.262-268
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• 2015

This study established an analytical method to simultaneously determine six organophosphorous pesticides [methyldemetone-S, diazinon, fenitrothion, parathion, phentoate, and O-ethyl O-(4-nitrophenyl) phenylphosphonothioate (EPN)] and carbaryl in water using a gas chromatography/mass spectrometry (GC/MS) system coupled with on-line micro extraction by packed sorbent (MEPS) and programmed temperature vaporizer (PTV) injector. Polystyrene divinylbenzene (PDVB) was used as a sorbent of MEPS. The effects of elution solvents, pH, elution volume and draw-eject cycles of samples on sample pretreatment process were investigated. Also, quality assurance and quality control (QA/QC) and the recovery of the pesticides in environmental samples were evaluated. The elution was performed using $30{\mu}L$ of a mixed solvent (acetone : dichloromethane = 80 : 20 (v/v)). Sample pretreatment processes were optimized with seven cycles of draw-eject of sample (1 mL) spiking an internal standard and sulfuric acid. At lower pH, the analytical sensitivity of diazinon decreased, but that of carbaryl increased. The method detection limit and the limit of quantification for this method were 0.02~0.18 and $0.08{\sim}0.59{\mu}g/L$, respectively. The method precision and accuracy were 1.5~11.5% and 83.3~129.8%, respectively, at concentrations of $0.5{\sim}5.0{\mu}g/L$. The recovery rates for all the pesticides except carbaryl in various environmental samples ranged 75.7~129.3%. The recovery rate of carbaryl in effluent sample was over 200% whereas carbaryl in drinking water, groundwater, and river water were in the acceptable range.

• Korean Chemical Engineering Research
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• v.55 no.2
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• pp.190-194
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• 2017

The combustion properties for the prevention of the fire and explosion in the work place are flash point, explosion limit, autoignition temperature (AIT) etc.. The using of the corrective combustion properties of the MSDS (Material Safety Data Sheet) of the handling substance for the chemical process safety is very important. For the safe handling of benzyl alcohol which is widely used in the chemical industry, the flash point and the AIT were measured. And, the lower explosion limit (LEL) of benzyl alcohol was calculated by using the lower flash point which obtained in the experiment. The flash points of benzyl alcohol by using the Setaflash and Pensky-Martens closed-cup testers measured $90^{\circ}C$ and $93^{\circ}C$, respectively. The flash points of benzyl alcohol by using the Tag and Cleveland open cup testers are measured $97^{\circ}C$ and $100^{\circ}C$. The experimental AIT of benzyl alcohol by ASTM 659E tester was measured as $408^{\circ}C$. The LEL of benzyl alcohol measured by Setaflash closed-cup apparatus was calculated as 1.17 vol% at $90^{\circ}C$. In this study, it was to possible predict the LEL by using the lower flash point of benzyl alcohol which measured by Setaflash closed-cup tester.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.4
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• pp.285-293
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• 2023

This study was conducted to determine the sowing limit period and predict growth in the northern region based on accumulative temperature for each growth stage of soybean cultivated in the southern regions of the Korean Peninsula. First, the results of a demonstration test in the central region (Yeoncheon) of the Korean Peninsula were very similar to the predicted and actual values on the date by growth stage obtained through cultivation. This method was then applied to seven agricultural climatic zones in the northern Korean Peninsula. The results predicted that regardless of ecotype, soybean could be grown and harvested in the southern and northern parts of Mt. Suyang, south of the East Sea, and in the central and northern inland areas. However, it was predicted that no ecotype could be grown and harvested normally in the northern alpine region. Furthermore, north of the East Sea, the prediction indicated that early and mid-maturing cultivars could be grown and harvested normally, but middle-late maturing cultivars appeared to lack the number of growth days. The sowing limit period also varied depending on the ecotype, although it was reached earlier as higher latitudes were approached; the period ranged from May 16 to June 26 in the northern and southern parts of Mt. Suyang, north and south of the East Sea, and central and northern inland areas. Furthermore, all ecotypes of the northern alpine region, as well as mid-late maturing cultivars in the north of the East Sea, were predicted to be unable to grow normally owing to the lack of number of days required for soybean growth and development.

• Korean Journal of Acupuncture
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• v.38 no.4
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• pp.282-289
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• 2021

Objectives : The purpose of this study is to construct a model of the possible thermal runaway of electronic moxibustion and to implement an appropriate risk management method. Methods : To reproduce the system error situation of the electronic moxibustion circuit equipped with microcontroller unit, temperature sensor and heater, a code was set to disable the signal input to temperature sensor and maintain "high" heating signal to heater. The temperature change of electronic moxibustion was compared between 3 types of heater module; module 1 consisting of a combination of heater+0 ohm+0 ohm resistance, module 2 consisting of a combination of heater+Polymeric Positive Temperature Coefficient (PPTC)+0 ohm resistance, and module 3 consisting of a combination of heater+PPTC+10 ohm resistance. The temperature change was measured using a polydimethylsiloxane (PDMS) silicone phantom. After maintaining surface temperature of the phantom at 31~32℃ for 20 seconds, electronic moxibustion was applied. After operating electronic moxibustion, the temperature change was measured for 660 seconds on the surface and 900 seconds at 2 mm depth. Results : Regardless of the module type, the time-dependent change in temperature showed a rapid rise followed by a gentle curve, and a sharp drop in temperature after reaching the maximum temperature about 10 minutes after the switching the moxibustion on. Temperature measured at the depth of 2 mm below the surface increased slower and to a lesser extent. Module 1 reached highest peak temperature with largest change of temperature at both depths followed by module 2, and 3. Conclusions : Through the combination of PPTC+resistance with the heater of electronic moxibustion, it is possible to limit the rise in temperature even with the software error. Thus, this setting can be used as an independent safety measure for the electronic moxibustion control unit.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.1
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• pp.199-204
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• 2020

In case of the silicon solar panel being used in Korea, the production specification is designed to give maximum output at the limit of -0.5 to 0.05℃, so the output of 0.45~0.55% decreases when the temperature rises by 1℃. As a result, the photovoltaic power generation is reduced according to the surface temperature rise of the photovoltaic module due to the characteristics of the solar cell. The decrease in output reduces the efficiency of photovoltaic power generation, and if the efficiency decreases, the result is that the profit of electricity sales according to the amount of photovoltaic power generation decreases. Therefore, this paper proposes a method of spraying cooling air to the lower (or surrounding) of the photovoltaic module when it is identified above the set temperature by the temperature detection sensor. In addition, the amount of power generated is increased by utilizing the lost solar energy, and by applying cooling function through cooling air, the power generation can be further increased.

• Journal of Sensor Science and Technology
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• v.26 no.3
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• pp.149-154
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• 2017

Detection of rain is one of the essential weather factors that are monitored by automatic weather stations in Korea. In this work, we studied the operation standards required for impedance-based rain detectors in terms of surface temperature and sensitivity, in an effort to establish a qualification procedure for rain detectors. The surface temperature of rain detectors was measured at varying air temperatures from $-30^{\circ}C$ to $20^{\circ}C$, considering the hypothetical presence and absence of rain/snow. In addition, the sensitivity of rain detectors was studied generating artificial raindrops of regular size. The sensitivity was evaluated in terms of the critical number of droplets that triggers the activation of the rain detector. We found that the sensitivity is affected by stationary, horizontal, and vertical droplet deposition methods. The critical number of droplets for the stationary deposition is higher than that for both horizontal and vertical depositions, which provides the maximum limit of droplets required to activate the detector. Based on our experiments considering surface temperature measurements and sensitivity tests, we suggest a revised version of surface temperature and sensitivity requirements for the qualification of impedance-based rain detectors.

• Journal of Environmental Science International
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• v.9 no.3
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• pp.215-221
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• 2000

The relationship between the distribution of sea surface temperature(SST) and dinoflagellate(Cochlodinium polykrikoides) bloom areas were studied. The SST data were derived from the infrared channels of AVHRR(Advanced Very High Resolution Radiometer) sensor on NOAA(National Oceanic and Atmospheric Administration) 12 and 14 satellites during 1995-1998. The initial water temperature at C. polykrikoides bloom was about 21${\circ}C$ at the coastal areas of the South Sea and along the shore of the East Sea of Korea during the summer season of 1995. The northern limit of red tides was coincident with that of 21${\circ}C$ isothermal line in the East Sea. The red tides that initially bloomed at the coast of Pohang on September 21, 1995 moved to the coast of Uljin on September 26, 1995. The skipped appearance of the red tides in the areas between Pohang and Uljin was due to the East Korean Warm Current, which was moving offshore from Pohang to approach to Uljin. The cold water which was formed by tidal front in the western coast of the South Sea and by upwelling water from deep layer in the southeastern coast of the Korean peninsula played a role in blocking the spreading of red tides during summer season in 1997 and 1998. In conclusion, the distribution of red tides appeared to be dependent on the initial water temperature at red tides bloom. The SST at the red tides varied from 21${\circ}C$ to 25${\circ}C$; 21${\circ}C$, 23${\circ}C$, 24 and 24-25${\circ}C$ in 1995, 1996, 1997 and 1998, respectively.