• Journal of the Korean Ceramic Society
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• v.28 no.6
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• pp.488-494
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• 1991

In this study, the effects of catalyst and DCCA content were investigated in order to determine the optimum conditions of monolithic silica gel formation through sol-gel process. Formamide, oxalic acid, glycerol and dimethylformamide are used as DCCA. To observe the phenomena in drying and heat-treating of gels, we examined structural exchange of gels using FT-IR, TG-DTA and XRD. Monolithic gels were obtained by adding formamide and dimethylformamide as DCCA. According to the heat treatment schedule, silica glass is prepared by heat-treatment up to 1050$^{\circ}C$.

• Bulletin of the Korean Chemical Society
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• v.23 no.11
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• pp.1519-1523
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• 2002

A procedure for preparing semiconductor/metal nanowire arrays is described, based on a template method which entails electrochemical deposition into nanometer-wide parallel pores of anodic aluminum oxide films on aluminum. Aligned CdS/Co heterostructured nanowires have been prepared by ac electrodeposition in the anodic aluminum oxide templates. By varying the preparation conditions, a variety of CdS/Co nanowire arrays were fabricated, whose dimensional properties could be adjusted.

• Journal of Magnetics
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• v.6 no.1
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• pp.13-18
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• 2001

Permalloy soft magnets have been produced by the powder injection molding process. Rheological characteristics of mixtures, debinding conditions, and the magnetic properties of permalloy after sintering have been investigated. A permalloy soft magnet with a permeability of 14200 could be obtained by preparing a mixture with a powder loading of 65.4 vol % and a PP/PEG binder systems solvent extraction, thermal debinding, and subsequent sintering at 1350$\^{C}$ in hydrogen. The permalloy soft magnet sintered in hydrogen had 95% of theoretical density and a magnetic induction of 13.2 kG in an applied magnetic field of 50 Oe.

• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.162-165
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• 1998

Characteristics of microcapsule wall depend on chemical and physical condition in procedure such as type and concentration of constituent and microencapsulation methods, thus, if the other process conditions are same, they depend on mainly types of wall-forming materials. Isocyanates used in this study are very important constituent as hard segments preparing urethane or urea by reaction with alcohol or amine. (omitted)

• Bulletin of the Korean Chemical Society
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• v.20 no.8
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• pp.875-878
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• 1999

A new concept ？？soft solution processing？？ has been introduced to fabricate advanced solid state materials in an economical, environmentally friendly, and energy and material efficient way. The prepared films show the desired and prospective properties despite of low temperature synthesis and no post-synthesis annealing. Successful examples demonstrate that soft solution processing is capable of preparing advanced materials with planned properties through the easy control of reaction conditions in a suitable aqueous solution in a single synthetic step without huge energy consumption and without any sophisticated equipment.

• Proceedings of the Korean Magnestics Society Conference
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• 2000.09a
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• pp.217-227
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• 2000

The permalloy soft magnet was produced by powder injection molding process. Rheological characteristics of mixtures, debinding conditions and the magnetic properties of permalloy after sintering ware investigated. The permalloy soft magnet with a permeability of 14200 could be obtained by preparing a mixture with a powder loading of 65.4 vol.% and PP/PEG binder system, solvent extraction, thermal debinding and subsequent sintering at 1350 $^{\circ}C$ in hydrogen. The permalloy soft magnet sintered in hydrogen showed a 95 % of theoretical density and a magnetic induction of 13.2 kG at the applied magnetic field of 50 Oe

• Korean Journal of Food Science and Technology
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• v.22 no.6
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• pp.707-710
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• 1990

To extend the shelf-life of kimchi, effective temperature in preparing room and salts concentration of product were monitored. The temperature in preparing room was excellent at $15^{\circ}C$ than $25^{\circ}C$ and effective salt concentration was 3.0% for storage. Under the these conditions, preservation temperature was desirable at $-1{\pm}1^{\circ}C$ and can be stored over 120 days. When the storaging temperature was $-5^{\circ}C$, it showed to freeze the tissue and juice of kimchi. The advisable packing time for storage was just after mixing.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.4
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• pp.44-52
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• 2001

This study performed factor analysis for 21 independent variables related to the effect of illumination and suggested the effect by multiple regression analysis on the relationship between the effect of illumination and the satisfaction of use of a dependent variable to find the effect of illumination in urban parks at night and the effect of illumination on the satisfaction of use. The results of this study are as follows; 1) Of the 21 independent variables used to study the effect of illumination in urban parks at night, the impact on safety and possibility of crime was highly. The effects of illumination by factor analysis were abstracted as effects of removing anxiety, securing safety, increasing use. 2) As a result of multiple regression analysis, independent variables influencing satisfaction of use in urban park were proved as effects of removing anxiety, securing safety, increasing identity, preparing atmosphere and increasing use. Also, the effect of securing safety was the most important factor; it showed a level of importance 2 times higher than the effect of removing anxiety, and 7.7 times higher than the effect of preparing atmosphere in relative contribution of the effect of illumination to satisfaction of use. 3) Of the effects of illumination influencing satisfaction of use in urban parks, the effect of securing safety and the effect of increasing visibility were more significant than the effects of removing anxiety, preparing atmosphere and increasing use. This fact means that personal safety an the identity of persons or facilities in the space of use should be considered with priority in planning or designing illumination. Also, it implies hat, for night use in urban parks, lightness of the space is required for general safety of use at parks, and proper illuminance on the activity in the space of use should be required. The subject parks of this study are 8 urban neighborhood parks. The model on the effect of illumination and the satisfaction of use depends on characteristics and conditions of location of he park and user class, so the subject parks and persons should be varied, and the difference by sex or ages should be suggested.

• KEPCO Journal on Electric Power and Energy
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• v.7 no.1
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• pp.101-105
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• 2021

Encouragement of DER from Korean government with several policies boosts DER installation in power system. When the penetration of DER in the grid is getting high, loss of generation with break-away of DER by abnormal grid conditions should be considered, because loss of high generation causes abnormal low frequency and additional operations of protection system. Therefore, KEPCO where is Korean power utility is preparing improvement in regulations for DERs connected to the grid to support abnormal grid conditions such as low and high frequencies or voltages. This is called 'Ride Through' because the requirement is for DER to maintain grid connection during required periods when abnormal grid conditions occur. However, it is not easy to have a test for ride through capability in reality because emulation of abnormal grid conditions is not possible in real power system in operation. Also, it is not easy to have a study on grid effect when ride through capability fails with the same reason. PHILs (Power Hardware In the Loop System) makes it possible to analyze power system and hardware performance at once. Therefore, this paper introduces PHILs test methods and presents verification of ride through capability especially for low voltage grid conditions.

• Journal of the Korean Society of Food Culture
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• v.12 no.3
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• pp.265-274
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• 1997

This study was conducted in ordor to find the most suitable conditions for producing the Doenjang with optimal odor compound contents. Three sample groups with the different preparing methods -Doenjang that has not gone through the soy sauce separation process (Doenjang A), Doenjang that has gone through the soy sauce separation process; Meju-20% salt water ratio of 1 : 4 (Doenjang B), and that with the ratio of 1.3 : 4 (Doenjang C)- were tested during different ripening periods. Odor compound contents were analyzed through Solvent Extraction Method and Simultaneous Steam Distillation Extraction (SDE). The number of odor compounds was greatest in Doenjang A and during the mid to late stage in each groups. In the sensory evaluation of Doenjang odors, Doenjang A received the highest scores in the categories of overall preferences, while Doenjang C got the lowest scores. Individual odor didn't vary significantly during ripening periods, but the overall odor and taste preference was highest in the samples ripened for 75 to 120 days. Stepwise multiple regression analysis of major odor compounds of Doenjang revealed that benzeneacetaldehyde is the major explanatory variable for offensive odor. Benzeneethanol, 3-methylthio-propanal and 4-methyl-phenol are the explanatory variables for salty odor, nutty odor and rancid odor, respectively. Odor compounds that contribute to the overall odor preference varied from the compounds that affect the taste preference.