• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.4
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• pp.313-319
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• 2022

In this study, the stability of cream containing 1% of cannabidiol (CBD) with more than 99% extracted from domestic Cannabis sativa was evaluated. The pH, hardness, content, and chromaticity were measured at intervals of 2 weeks under storage conditions for each temperature for 12 weeks (4 ℃, 25 ℃, 37 ℃, and 45 ℃). The pH of the experimental group containing 1% of CBD tended to decrease more than that of the control group. As a result of measuring the change in the content of CBD in the cream under each temperature for 12 weeks using HPLC, the difference in the amount of decrement according to temperature was confirmed. It was confirmed that as a result of measuring the chromaticity using color difference meter, the yellowness of the cream containing CBD increased according to the increase by the storage period and temperature compared to the control group. From the above results, it was confirmed that the content decrease and color change according to the temperature of the pH 5 ~ 6 cream formulation containing CBD. When CBD is applied to medicine and cosmetic formulations in the future, it is considered that research and development should be conducted in consideration of the change in the quantity and physicochemical quality of CBD under the temperature.

• Journal of Wetlands Research
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• v.13 no.2
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• pp.265-273
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• 2011

Hyporheic zone, where groundwater-stream water mixing occurs, sensitively responds to heat of groundwater and stream water temperature. Variation of stream water temperature has short time period and time dependent, because stream water temperature is influenced by daily fluctuation and seasonal air temperature. On the other hand, groundwater temperature is insignificant. In this study, we conducted 1-dimensional heat transfer analysis. The results show that there are differences of temperature distribution between gaining stream and losing stream with flux in hyporheic zone. Especially, variations of hyporheic water temperature show a significant difference in adjacent streambed, Also, the results shows that distribution of temperature was more affected by groundwater direction than intensity of flux.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.4
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• pp.99-106
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• 2012

This study presents estimation method of temperature-dependent thermal conductivity by using solution of inverse heat conduction problem. Time and depth temperature distribution data from full-scale fire test were used for estimating temperature-dependent thermal conductivity on hybrid-fiber reinforced shield tunnel lining. At short heating time, estimated thermal conductivity sharply decreased within $100^{\circ}C$. On the other hand, it reflected thermal properties of concrete and effect of steel fiber at heating time of measured maximum heating temperature. Thus arbitrary time should be determined to estimate temperature-dependent thermal conductivity in time zone of measured maximum heating temperature. Estimated temperature-dependent thermal conductivity is similar to results of other study.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.272-273
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• 2011

본 논문에서는 하계와 동계 각 기간별 최대전력수요와 온도를 이용한 수요관리 프로그램 적용일와 적용시간을 추정하는 방법을 제안하였다. 사례연구에서는 국내 전력수요 데이터를 바탕으로 제안된 방법을 2011년~2012년에 적용하여 수요관리 적용일과 적용시간을 추정하였다.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.1
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• pp.20-25
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• 2020

Spatial simulation of crop growth often requires application of management conditions to each cell. In particular, it is of great importance to determine the temperature conditions during the nursery period for rice seedlings, which would affect heading date projections. The objective of this study was to determine the value of TMPSB, which is the parameter of ORYZA2000 model to represent temperature increase under a plastic tunnel during the rice seedling periods. Candidate values of TMPSB including 0℃, 2℃, 5℃, 7℃ and 9℃ were used to simulate rice growth and yield. Planting dates were set from mid-April to mid-June. The simulations were performed at four sites including Cheorwon, Suwon, Seosan, and Gwangju where climate conditions at rice fields common in Korea can be represented. It was found that the TMPSB values of 0℃ and 2℃ resulted in a large variation of heading date due to low temperature occurred in mid-April. When the TMPSB value was >7℃, the variation of heading date was relatively small. Still, the TMPSB value of 5℃ resulted in the least variation of heading date for all the planting dates. Our results suggested that the TMPSB value of 5℃ would help reasonable assessment of climate change impact on rice production when high resolution gridded weather data are used as inputs to ORYZA2000 model over South Korea.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.128-137
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• 1999

In this study, shiitake mushrooms were dried by hot air, vacuum and freeze drying methods and theire physical properties were compared. Since the pore size affects the amount of absorption, the characteristics of water sorption were investigated at various humidities and temperatures. Results showed that the freeze dried product had the greatest pore area and the highest absorption capacity. However, all the dried samples showed similar quality. The browning degrees were severely changed with increased relative humidities and temperatures. Among these drying methods, the freeze drying gave the greatest change in browning degree. The GAB monolayer moisture contents of the dried shiitake mushroom were $5.3{\sim}7.7%$. The prediction model was also provided using parameters such as relative humidity, temperature and pore area.

• Korean Journal of Environment and Ecology
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• v.26 no.2
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• pp.156-185
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• 2012

In order to investigate vertical plant distribution on Osaek valley of Mt. Seorak by temperature change, vascular plants of fourteen areas with 100-meter-high difference were surveyed from the Osaekgyo(345m alt.) to the Daecheongbong(1708m alt.). A total of 449 taxa belonging to 94 families, 279 genera, 397 species, 5 subspecies, 45 varieties, and 2 forma were vegetated on survey areas. Around 500 m high did species diversity of vascular plants decrease rapidly. The Detrended correspondence analysis(DCA) divided distribution of vascular plants into five groups; areas below 500m alt., 500~900m alt., 900~1400m alt., 1,400~1,600m alt., and areas above 1,600m alt.. These results showed that vegetation of vascular plants on investigated areas has high correlation with climate elements of temperature. Vascular plants should be crowded within their own optimal ranges of vegetation. Climate change would result in shift of these distribution ranges, and thus vegetation shift will be happened accordingly.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.502-508
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• 1999

Microbiological characteristics of low salt Mul-kimchi was examined. Mul-kimchi was prepared by mixing of radish (25%), green onion (2.4%), red pepper (1.9%), garlic (1.9%) and salt (0, 0.2, 0.5, 1.0, 1.5, 2.0, 2.5, 2.5, 3.0%) in water and fermented at 4, 15 and $25^{\circ}C$ for 10 days, respectively. During fermentation period, total cell, Leuconostoc sp., Lactobacillus sp., Streptococcus sp., Pediococcus sp., coliform bacteria, gram (-) bacteria and yeast cell number were counted on their selection media. The microbes in Mul-kimchi were isolated and identified. Total cell number increased as salt concentration decreased and fermentation temperature increased. Lactic acid bacteria showed the highest number in 1.0% salt concentration. Yeast cell number increased with increase of salt concentration. Lactobacillus sp. were identified Lactobacillus plantarum and L. pentosus in Mul-kimchi containing $0.2{\sim}1.0%$ salt while those of Mul-kimchi containing 3.0% salt were Lactobacillus plantarum and L. brevis. The other lactic acid bacteria were identified Leuconostoc citrum, Leu.mes.ssp.mesenteroides/dextranicum and streptococcus facium in Mul-kimchi containing $0{\sim}3.0%$ salt while Pediococcus sp. was not detected. Gram-negative Aeromonas hydrophila, Pseudomonas fluorescens, Pseu. aureofaciens and yeast Candida pelliculosa, Cryptococcus laurentii were identified in the Mul-kimchi.

• Land and Housing Review
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• v.4 no.4
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• pp.417-424
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• 2013

The purpose of this study was to investigate the characteristics of the indoor air quality by season. The surveyed houses were 48 new apartment complex in 2012 across the country. The houses were carried out the bakeout before the test. The measuring method was "Indoor air quality testing standards process" and the measured items were formaldehyde, benzene, toluene, ethylbenzene, xylene, styrene average emissions. All the items were more emitting during the summer. From June to September the average concentration of formaldehyde emission was higher than other seasons. The average emissions of benzene concentrations in all seasons were released in small quantities. Average emissions of toluene and ethylbenzene concentration from April to August showed slightly higher emissions. Xylene and styrene concentration showed the highest emissions at April, but without large deviations throughout the year.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.4
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• pp.116-124
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• 2015

The objective of this study is to evaluate the effects of the replacement levels of grinded fly-ash on the repaired mortar based on a polymer. The main parameters are the curing temperature and replacement levels of grinded fly-ash. The curing temperature and the replacement levels of grinded fly-ash are varied at $40^{\circ}C$, $20^{\circ}C$ and $5^{\circ}C$, and between 0% and 35% of the total binder by weight, respectively. The flow in fresh mortar and compressive strengths according to ages, the relationship of stress-strain, elastic modulus and modulus rupture in hardened mortar, as well as scanning the electron microscopy and the X-ray diffraction of mortar, were measured, respectively. The test results showed that the flow, elastic modulus and modulus rupture are great in mortar specimens with 20~30% of the replacement levels of grinded fly-ash. In addition, compressive strengths according to ages were affected by the replacement levels of grinded fly-ash and the curing temperature indicated that the strength development ratio of mortar with 20% of the replacement levels of grinded fly-ash was greater than others. In the prediction of the compressive strength specified by the ACI 209 code, the strength development at an early and late age can be generalized by the functions of the replacement levels of grinded fly-ash and the curing temperature. In the analysis of scanning the electron microscopy and the X-ray diffraction, the number and intensity of peaks increased and the form of CSH gels on the surface of the particle of grinded fly-ash was observed.