• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.3
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• pp.119-125
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• 2013

IInsulation material is generally used for preventing heat loss from heat transport fluids, and water absorption severely reduces the insulation property. The purpose of this study is to evaluate the amount of water absorption supplied by the pouring method and spraying method, to investigate the effects of water absorption on the thermal conductivity of an insulation material, and modeling the relation between water absorption and thermal conductivity. E-glass, a kind of glass fiber, and HYPERLITE, mainly composed of pearlite, are selected, to compare hygroscopic and insulation properties. E-glass is found to have much higher water absorptivity, compared to HYPERLITE. The thermal conductivity of the water-absorbed E-glass is increased by more than 150%, compared to that of no absorption, while variation of the thermal conductivity of HYPERLITE with water absorption is insignificant. A three-stage model of water absorption for thermal conductivity is developed, and the modeling results are found to be in good agreement with the experimental data.

• Journal of Sericultural and Entomological Science
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• v.44 no.1
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• pp.37-41
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• 2002

The attaching treatment of sericin onto polyester fiber was attempted to improve its sanitary properties. Generally, sericin, a gummy material covering the outer layer of silk filament, is subjected to be removed during degumming process of silk textile process. For this study, sericin particle dissolved within the degumming waste water could be collected by sedimentation of polyaluminium chloride. It was revealed that sericin particle were attached onto the surface of polyester fiber evenly by treatment of glutaraldehyde, a crosslinking agent. A frictional static charge of the treated polyester fabric could be improved, while its hygroscopic property was little changed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.2
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• pp.328-332
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• 1994

The purpose of present paper is to compare and analyze the quality of imported Chinese products with the Korean local products in terms of proximate composition, character of external appearance , ingredient composition of dried bracken , dried radish cubers, meju , dried pollack, dried mussel , and dried brown seaweed(Undaria puinnatidifida) which were imported between Oct., and Dec. 1992 and distributed in the market. Moisture recovery of dried products resulted in changed shape and incomplete moisture recovery due to an excessive drying in consideration of hygroscopic property in the course of distribution. The amounts of water soluble brown pigment were two times greater in Korean dried pollack and bracken than those of Chinese products. The content of volatile basic nitrogen (VBN) were twice in Chinese dried pollack, and this may be due to foregin odor from a long transport time and distribution process. The contents of aflatoxin in Korean products were not detectable and these of Chinese products were 5 $\mu\textrm{g}$(%) in dried pollack, bracken and radish cuber. the remaining agricultural chemicals were not detectable in all products. Because of poor technique and facilities, the external appearance of Chinese products especially dried mussels and dried pollack were not uniformed in size and color. Discoloration and foregin substance such as hair, dust were checked , Korean products were mostly packed in small size in PP or bag, and Chinese products were packed in bulk size and distributed as a bulk.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.2
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• pp.70-74
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• 2017

Two milling methods, dry vibration milling and wet ball milling, were used to prepare $Na_{2/3}(Ni_{1/3}Mn_{2/3})O_2$ powders as a cathode material for sodium ion batteries. The morphology and electrochemical property of the two powders with different milling processes were compared to each other. The particle size is less than $1{\mu}m$ in the dry vibration milled powder, while lots of larger particles than $1{\mu}m$ were found in the wet ball milled one. The single phase of $Na_{2/3}(Ni_{1/3}Mn_{2/3})O_2$ was obtained in the temperature range of $875{\sim}900^{\circ}C$. The discharge capacity and discharge voltage of the powder prepared by the dry process were higher than those of one prepared by the wet process.

• Fashion & Textile Research Journal
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• v.17 no.2
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• pp.247-257
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• 2015

This study conducted a questionnaire survey on the real condition of clothing with focus on related to general motorcycle wear and motorcycle jacket targeting a quick service carrier affiliated with a quick service business in Seoul. In addition, this study is aimed at providing basic data on developing the motorcycle jacket, whose motional flexibility, safety and functionality are excellent, exclusively for a quick service carrier by grasping inconveniences and problems and deducting improvements on the basis of the questionnaire survey. This study, on the basis of the questionnaire survey results, grasped the general part related to quick service and motorcycle wear, such as their general matters, whether they were having on the motorcycle wear in the middle of doing business, whether it's necessary to wear the motorcycle wear, where they had a driving accident, and kinds of external injuries, etc. From the gathered results of analysis of the collected questionnaires, the item which got the lowest satisfaction was the inconvenience from the chafed front neck when driving. Besides, the results showed carriers' complaints like the elbow part felt tight, discomfort in the horizontal movement of the shoulders or back, and wind admission in between zippers. In addition, the respondents showed complaints in the item about hygroscopic property and air permeability at the armpits and back part, and 5 items about material flexibility, wind shielding property, living water repellency, weighty sensation, and night visibility were found to be low in respondents' satisfaction.

• Journal of the Korean Wood Science and Technology
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• v.45 no.5
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• pp.519-524
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• 2017

Physical, mechanical and deteriorating properties of Phellodendron amure were investigated. Air dried density located indoor was 0.41 but $0.43g/cm^3$ outdoor. In oven dry shrinkage, T/R ratio for located indoor was 1.40 but 1.32 outdoor. Hygroscopic property at $40^{\circ}C$ with 90% relative humidity was 16.30% for indoor and 15.80% for outdoor. Compressive strength for outdoor conditioned sample was 43.81 MPa but 40.33 MPa for indoor conditioned. Also bending strenght for outdoor conditioned was 84.63 MPa but 68.80 MPa for indoor conditioned. Impact strength was 3.43 and $4.00J/cm^2$ indoor and outdoor, respectively. Hardness at cross-section was 47.92 and 49.20 MPa indoor and outdoor, respectively. With one-year conditioning at indoor or outdoor, there was no significantly different in strength properties, which came from strong resistance for deterioration. Also Phellodendron amure wood showed dimensionally stable raw material based on low T/R ratio.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.4
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• pp.470-482
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• 2008

Seasonal variations of chemical composition and optical properties of aerosols at Seoul and Gosan were investigated using the ground-based aerosol measurements and an optical model calculation. The mass fraction of elemental carbon was $8{\sim}17%$, but its contribution on light absorption was high up to $29{\sim}48%$ in Seoul. In Gosan, the contribution of water soluble aerosols on aerosol extinction was $83{\sim}94%$ due to the high mass fraction of these particles in the range of $56{\sim}88%$. Model calculation showed that the water holding capacity of aerosols was larger in Gosan than in Seoul because of higher relative humidity and temperature along with abundant water soluble aerosols. Difference between measured and calculated aerosol optical depths was the highest in summer. This was because aerosol optical depth calculated from ground-based measurements could not consider aerosol loadings at high altitude in spite of high column-integrated aerosol loadings observed by Sun photometer. Although hygroscopic growth was expected to be dominant in summer, the mass concentration of water soluble aerosols was too low to permit this growth.

• Fashion & Textile Research Journal
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• v.10 no.6
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• pp.1006-1013
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• 2008

This study is basic material for development of a smart girdle. Through the intentionally sampling of 313 consumers from teenagers to the forties who have experienced wearing girdles, lifestyles on consumer's age, attitude to health, favor of warm functional girdle, and possibility to acceptance were surveyed and analyzed by questionnaire. The result of the study are summarized as followed. 1. Analysis about lifestyle with warmth and attitude to health showed that subjects in their thirties and forties have higher than teenagers and the twenties in frequency of distribution. This means people are tend to have more attention to warmth and health as they grow older. 2. In result about analysis of characteristic of wearing girdle, subjects were prefer girdle made of cotton which have superior permeability and hygroscopic property. The reason that wearing girdle is to complement of weak points of body somatotype in the thirties and forties and feel the stability during menstrual period in the twenties and teenagers. The time zone of putting on girdle is mainly winter while one is out wearing one-piece or skirt. 3. When surveyed about the preference to functional warmth girdle and possibility to acceptance, the results were that the subjects in their thirties were first, forty something was second, followed by subjects in their twenties, teenagers. It was shown that over 60% subjects were highly distributed. With regard to necessity of functional warmth girdle, every age groups were shown over 3.6 at average. This result was inferred that subjects had positive possibility to acceptance about functional warmth smart girdle.

• Archives of Pharmacal Research
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• v.26 no.12
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• pp.1002-1008
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• 2003

Ferulic acid (3-methoxy, 4-hydroxy cinnamic acid) is a flavoid component possessing antioxidant property. The compound is currently under development as a new drug candidate for the treatment of the dementia. The objective of this preformulation study was to determine the physicochemical properties of ferulic acid. The n-octanol to water partition coefficients of ferulic acid were 0.375 and 0.489 at the pHs of 3 and 10, respectively. Accelerated stability study for ferulic acid indicated that the t 90 value for the drug was estimated to be 459 days at $25^{\circ}C$. Ferulic acid was also found to be unstable under the relative humidity of more than 76%, probably because of the hygroscopic nature of the drug. In order to study compatibility of ferulic acid with typical excipients, potential change in differential scanning calorimetry spectrum was studied in 1: 1 binary mixtures of ferulic acid and typical pharmaceutical excipients (e.g., Aerosil, Avicel, CMC, Eudragit, lactose, PEG, PVP, starch and talc). Avicel, CMC, PVP and starch were found to be incompatible with ferulic acid, indicating the addition of these excipients may complicate the manufacturing of the formulation for the drug. Particle size distribution of ferulic acid powder was in the size range of 10-190 $\mu$m with the mean particle size of 61 $\mu$m. The flowability of ferulic acid was apparently inadequate, indicating the granulation may be necessary for the processing of the drug to solid dosage forms. Two polymorphic forms were obtained by recrystallization from various solvents used in formulation. New polymorphic form of ferulic acid, Form II, was obtained by recrystallization from 1,4-dioxane. The equilibrium solubility for Form I was approximately twice of that for Form II. The dissolution rate of Form II was higher than that of Form I in the early phase (<6 min). Therefore, these physicochemical information has to be taken in the consideration for the formulation of ferulic acid.

• Korean Chemical Engineering Research
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• v.56 no.4
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• pp.555-560
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• 2018

The high temperature stability of a chloride mixture, $NaCl-KCl-ZnCl_2$ (NaKZn-Chloride), is investigated to evaluate its potential as a thermal storage material. A thermal storage media should maintain a stable thermal properties within the temperature range of heat storage. Results from an a priori experiment showed that the NaKZn-chloride is stable only up the much lower temperature, while its stability limit is reported to be $850^{\circ}C$ in the literature. This study aims to investigate if the thermal property is changed by the moisture absorbed in the heat storage material. The effect of moisture content on the thermal properties was measured. The results show that the melting point remains the same regardless of the amount of moisture absorbed. Meanwhile, the high temperature stability is lower for the moisture treated samples. The results of this work infer that the loss of a hygroscopic thermal storage media can be reduced by avoiding its contacts to moisture in designing high temperature thermal storage systems.