• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.2
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• pp.179-184
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• 2020

Elasticity and softness of the skin depend on the level of moisture present in the stratum corneum, which is known to be affected by various environmental changes, such as cold and hot winds and dry environments. However, not many studies have been conducted on changes in skin moisture and the degree of recovery due to individual skin differences. In the present study, we aimed to investigate the effect of warm air heating on skin hydration levels and develop moisturizing formulas to improve lowered skin hydration levels. In order to deliver warm air heating condition, heating dryer (40 ℃, 6 m/s, 30 cm apart from forearm) was applied into inner forearm of healthy subjects (male: 10, female: 39, age: 25 - 63) Among 49 subjects, 26 subjects showed significantly lowered skin hydration levels until 30 min after warm air heating exposure (lowered group). In addition, moisturizing cream with high water holding capacity was applied to forearm of 10 subjects in lowered group for 3 weeks and skin hydration levels after warm air heating were significantly improved at the levels of before application of warm air heating. From this study, we found out that there is a skin type that skin hydration levels are significantly decreased under warm air heating condition (dehydrated skin) and this dehydrated skin can be improved by moisturizing formulas with high water holding capacity.

• Journal of The Korean Society of Agricultural Engineers
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• v.51 no.5
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• pp.79-86
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• 2009

This research performed to analyze surplus solar energy, which is generated from a greenhouse during daytime, and to make the basic materials for designing thermal energy storage system for surplus solar energy. For this goal, it analyzed the surplus solar energy coming from two types of greenhouse. The results of this research are as per the below: In the case of 1-2W-type greenhouse, this research gave the same temperature and ventilation condition regardless of regions, but it was judged that the quantity of surplus solar energy could be greatly changed, depending on the energy consumed for the photosynthesis and evapotranspiration of crops in the greenhouse, on the heating temperature during daytime and night, on the existence/non-existence of a curtain and its warming effect, and on the ventilation temperature suitable for the overcoming of high temperature troubles or for the optimum cultivation temperature. In the case of a single-span greenhouse, there was a big difference in energy incoming and outgoing by month, but throughout seasons, 85.0 % of the total energy put into the greenhouse was solar energy and the energy input by heating was just 15.0 % of the total. 26.4 % of the total energy input for the greenhouse was used for photosynthesis and evapotranspiration of crops, and 44.2 % of the remaining 73.6 % went out in the form of radiant heat through the surface of the greenhouse. That is, 25.2 % of the total energy loss was just the surplus solar energy. 67.6 % of the total heating energy was concentrically used for 3 months from December to February next year, but the surplus solar energy during the same period was just 19.4 % of the total annual quantity so it was found that the given condition was more restrictive in directly converting the surplus heat into greenhouse heating. Under the disadvantageous circumstance of 3 months from December to February next year, it was possible to supplement 28 % (December) $\sim$ 85 % (February) of heating energy with surplus solar energy.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.5
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• pp.653-659
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• 2008

In this study, the optimum pre-heating condition was investigated to improve water extraction yield of Phelinus linteus tea. Pre-heating was carried out using drying oven or hot plate at different temperatures and times, and extraction yield was estimated by measuring optical density at 370 nm and soluble solid content. The highest optical density and soluble solid content of Phelinus linteus tea were observed when pre-heated at $70{\sim}80^{\circ}C$ for 30 minutes in drying oven. Pre-heating in drying oven resulted in also faster color changes of Phelinus linteus tea at lower temperature. According to the organoleptic evaluation, pre-heated Phelinus linteus tea in drying oven at $70{\sim}80^{\circ}C$ for 30 minutes was preferred compared to the non-treated. In conclusion, pre-heating in drying oven at $70{\sim}80^{\circ}C$ for 30 minutes was found to be the most efficient conditions to increase extraction yield of Phelinus linteus tea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.3
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• pp.268-274
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• 1984

The purpose of this study was to investigate the physico-chemical effects of a potato starch and a purified potato starch under the condition of the microwave heating. They were exposed to the microwave energy in a 950 W, 2,450 MHz oven for 30 through 120 seconds. As the microwave heating time was increased, the contents of moisture and the crude fat of the samples were remarkably decreased irrespective of the starch composition, but on the other hand the contents of crude ash was slightly decreased and the crude protein was almost unchanged. The rings of crystallinity come to gradually changed in the X-ray diffraction pattern, and then the only 1 ring, of which interplanner spacing is wide, is changed strikingly. As the microwave heating time is increased, the starch granules which observed by a scanning electron microscope were broken partially with a special form, and the granules of purified potato starch were broken faster than those of potato starch. With the same condition that the microwave heating time was increased, while the gelatinization temperature comes to fall, the swelling power and the solubility were increased. Besides these, while the gelatinization temperature of the purified potato starch was lower than that of the potato starch, both the swelling power and the solubility of the purified potato starch is higher than those of the potato starch.

• Journal of the Korean Institute of Gas
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• v.20 no.6
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• pp.43-49
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• 2016

In this paper, purpose of study is emissions characteristics according to effects of heating value variations of CNG fuel in a dual-fuel engine fueled by diesel and natural gas. For heating value variation of CNG fuel, nitrogen gas was mixed with pure CNG fuel. So the higher heating value was changed from $10,400kcal/Nm^3$ to $9,400kcal/Nm^3$. Under one condition of CNG substitution rate was fixed at 80%, diesel fuel was injected at a fixed injection timing of 16 CAD BTDC and fuel pressure was also fixed at 110 MPa. The condition of tested engine was 1800 rpm and 500Nm. Emissions were sampled in exhaust pipe was located at downstream turbocharger. As a result, emissions characteristics were checked in heating value variations of CNG fuel with mixed nitrogen gas THC, $CH_4$ and CO emissions decreased and NOx and $CO_2$ increased.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.3
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• pp.85-92
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• 2015

SiC crystals are well known for their true potential as high power devices and their crystal growth activity is actively carried out in domestic as well as in abroad. Until now the process to grow this crystal has been done by sublimation technique using radio frequency induction heating method. However in order to get better quality of SiC crystals, the stability of temperature is needed because SiC crystal tends to transform to other polytypes. So, the possibility of SiC crytals growth was evaluated by different heating method. This study aimed to observe whether the resistant heating method would show stable growth and better quality of SiC single crystal than that of RF induction heating. As a result, polycrystalline SiC crystals were grown by the growth rate of 0.02~0.5 mm/hr under the condition of $2100{\sim}2300^{\circ}C$ at the bottom side of the crucible and 10~760 torr. The polycrystalline SiC crystals with 0.25 and 0.5 mm in thickness were grown successfully without seed and characterized by optical stereo microscopic observation.

• Progress in Superconductivity
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• v.8 no.2
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• pp.186-192
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• 2007

High $J_c\;YBa_2Cu_3O_{7-x}$ superconducting films have been fabricated $LaAlO_3(100)$ substrate by MOD method using dichloroacetic acid(DCA) as chelating solvent for preparing precursor solution. Heating rate was varied in order to optimize the calcination heat treatment condition in DCA-MOD method. Coated films were calcined at lower temperature up to $500^{\circ}C$ in flowing humid oxygen atmosphere. The heating rate was calcined from $13.3^{\circ}C/min\;to\;0.28^{\circ}C/min$. Conversion heat treatment was performed $800^{\circ}C$ for 2 h in flowing Ar gas containing 1000 ppm oxygen with a humidity of 9.45%. Surface and cross sectional SEM microstructures showed that particle sizes were increased with heating rate at a calcination step. The amount of pores was increased with heating rate in the calcined films. Dense microstructure and sharp texture were developed in an YBCO films after conversion heat treatment. A high critical current density (Jc) of $1.26MA/cm^2$ (@77 K and self-field) was obtained for the YBCO film which was prepared with a heating rate of $0.28^{\circ}C/min$.

• Journal of Korean Medicine Rehabilitation
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• v.21 no.4
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• pp.67-76
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• 2011

Objectives: The aim of this review was to investigate studies on fire needle and to propose for the better method of studies in the future. Methods: Studies related to fire needle were searched with electric database for this study, and 10 domestic and overseas databases were included. Results: 19 clinical studies were analyzed in terms of condition, time of heating, number and frequency of treatment, number of heating, safety procedure or device aid reports of adverse events. Also 3 review studies were summarized. The number of studies was increasing and the kind of diseases to treat with fire noodle were various. Especially musculoskeletal diseases like ligament lesion and lumbago were noticeable. Heating-after-insertion method was recently proposed but the use of term was confusing. The report of adverse events or safety procedure was rare. Also there was an effort to develop more convenient and safer device. Conclusions: High quality clinical trial en fire needle is needed especially to compare 2 methods, heating-after-insertion and heating-before-insertion. And studies need to report safety procedures and adverse events to evaluate the safety of fire needle therapy.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.3
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• pp.247-253
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• 2011

Purpose: The changes in properties of plastic lens due to heating was investigated. Methods: Plastic lenses of -2.00 diopter were heated at 60-100$^{\circ}C$, and then changes of refractive power, surface condition and transmittance were examined. Results: It was shown that the changes of lens surface due to heating happened at 70$^{\circ}C$ for 1h, 75$^{\circ}C$ for 10 min and 100$^{\circ}C$ 10 sec, respectively. More serious crack was occurred in high index lens and at higher heating temperature, respectively, and transmittance decreased depending on the extent of the damage on the surface of lens. Conclusions: Heating at temperatures above 70$^{\circ}C$ drives cracks on the surface of lens. Optician should recommend an appropriate lens considering the wearer's working conditions and guide for paying attention when they use eyeglasses.

• Food Science of Animal Resources
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• v.28 no.4
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• pp.415-421
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• 2008

This study evaluated the effects of thermal processing combined with high pressure on the properties of cooked pork. Pressurization followed by heating (PFH), heating followed by pressurization (HFP) and heating under pressurization (HUP) treatments were compared to a heated only control. Cooked meat without simultaneous pressurization showed little or no decrease in water binding properties relative to the control, regardless of the sequence of pressurization and heating. However, HUP treated pork had significantly higher water binding properties than the control (p<0.05). The pH values of all treatments were not significantly different with the exception of HUP at 300 MPa. The HUP treated pork showed the best tenderizing effects among all the treatments tested and the effect was more significant at increased pressure levels (p<0.05). In addition, increasing pressure levels significantly increased the L-values of pork (p<0.05). PFH and HFP treated pork had significantly lower a-values (p<0.05), while no significant differences were observed in HUP. HUP treated pork had the lowest b-values at 100 MPa. however, the differences were not significant at increasing pressure levels. These results indicate that heating under pressure is the best cooking condition for improving the quality characteristics of pork without adversely affecting its appearance.