• Journal of Korean Society on Water Environment
• /
• v.30 no.5
• /
• pp.559-567
• /
• 2014

Since the ocean dumping of organic wastes is prohibited under the London Convention, the need for land treatment of food waste leachate (FWL) has significantly been growing in recent years. This study was conducted to use thermal solubilization to turn FWL into a form that can easily be degraded during the anaerobic digestion process, thereby reducing the percentage of solids and increasing the production of methane. To derive the optimal operating conditions of thermal solubilization, a laboratory-scale reactor was built and operated. The optimal reaction temperature and time turned out to be $190^{\circ}C$ and 90 min, respectively. The BMP test showed a methane production of 465 mL $CH_4/g$ $COD_{Cr}$ and a biodegradation rate of 90.1%. The production of methane rose by about 15%, compared with no the application of thermal solubilization. To reduce the solid content of FWL and improve the methane production, therefore, it may be helpful to apply thermal solubilization to pre-treatment facilities for anaerobic digestion.

• Journal of Korean Society of Water and Wastewater
• /
• v.23 no.4
• /
• pp.491-497
• /
• 2009

The purpose of this study is to propose a method of controlling redtide microbes which grow abundantly and form harmful algal bloom in eutrophic waterbody with yellow loess and hydrogen peroxide. In the laboratory test, hydrogen peroxide was applied to single species of C. polykrikoides and multispecies of redtide microbes. The seawater was evaluated by the pre-test analysis including chlorophyll-a, luminance and transmittance. The test results showed that both single and mixed species of redtide microbes could be controlled with the dose of 30mg $H_2O_2/L$. Residual hydrogen peroxide was completely decomposed with the addition of powdered yellow loess at 2g/L~10g/L. However, the decomposition rate of residual hydrogen peroxide for sintered granular yellow loess was relatively low compared to the use of powdered one. With the addition of dissolved oxygen concentration was increased at a rate of 0.013 mg DO/mg $H_2O_2$, which is a little lower than the one predicted theoretically. No evidence for any detrimental effects on Artemia, a type of brine shrimps, was shown up to the concentration of 100mg $H_2O_2/L$.

• Journal of Surface Science and Engineering
• /
• v.50 no.1
• /
• pp.10-16
• /
• 2017

This article reports for the first time on the lateral growth of PEO (plasma electrolytic oxidation) films on Al1050 alloy by the application of anodic pulse current in an alkaline electrolyte. Generation of microarcs was observed at the edges initially and then moved towards the central region with PEO treatment time. Disc type PEO film islands with about $20{\mu}m$ diameter were formed first and they grew laterally by the formation of new disc type PEO films at the edge of pre-formed PEO islands. The PEO film islands were found to be interconnected completely and form a continuous PEO film when generation of small size microarcs are terminated at the central part of the specimen, resulting in very smooth surface with low surface roughness less than $1{\mu}m$ of $R_a$. Further PEO treatment after the complete interconnection of PEO films islands showed local thickening of PEO films by vertical growth. It is concluded that very smooth PEO film surface can be obtained by lateral growth mechanism rather than vertical growth of them.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.14 no.1 s.33
• /
• pp.55-67
• /
• 1990

This is a review on the longitudinal transformation of the Japanese trousers, which is prepared as a pre-study for the comparative analysis of the forms of Korean and Japanese folk trousers. The special traits of the Japanese trousers are found to be as follows: 1) The Japanese trousers seem to have their root in the Northern-Asian or Schithian culture. 2) While the ancient forms of Japanese trousers, esp., those of the 8C before include the same types as Korean folk trousers, the Medieval and Recent era trousers quite differ and transform themselves into the unique Japanese type. 3) All Japanese trousers can largely be classified into formal and functional trousers. Formal trousers play important role as one of the ceremonial wardrobe and are treated rather as an outermost-wear than as an inner-wear. 4) The formal trousers have skirt-like features with much fullness as are presented in many deep pleats, long crotch lines and long sashes connected to the belt; the femine trousers even omit crotch line. 5) The principal forms of Japanese trousers consist of I, $\wedge,\;\wedge$; the $\lambda$ form of Korean and Chinese type had never existed. 6) Varieties of the composite type of Japanese-Western style appear among the trousers of recent time.

• The Korean Journal of Health Service Management
• /
• v.8 no.2
• /
• pp.245-254
• /
• 2014

The objective of this study is to identify the relationship of dietary habits and health habits with dental caries subjective symptoms and to present data on nutritional education related to oral health. The subjects of this study are 334 teachers at pre-schools. The subjects of the study were selected using the convenience sampling method. Surveys were taken with the self-entry questionnaire method. It was found that dental caries subjective symptoms were higher among study subjects who ate appetizers frequently through the day, consumed more milk and other dairies and sugars, drank alcohol more, did less exercise, smoked, and had less sleep time. Systematic diet control and nutritional education must be strengthened to form proper dietary habits and health habits for preventing dental caries.

• Journal of the Korean Society of Food Culture
• /
• v.26 no.2
• /
• pp.170-177
• /
• 2011

We examined household's food expenditures in this study. The empirical work outlined here used quarterly data from 2003 Q1 to 2010 Q3. All variables are in log form and were obtained from the Korea National Statistical Office. The food items included cereals, dairy products, fruits, meat, vegetables, and alcoholic beverages. We applied the ordinary least squares method to a model consisting of household income and seasonal dummies. This is because household expenditures are ordinarily a function of income and have seasonal characteristics. The household's food consumption patterns also reflect the prevailing social and environmental circumstances. This study showed that the income coefficients of cereals, meat, dairy products, and alcoholic beverages tend to increase in the long-run, whereas those of vegetables and fruits decreased. The results also revealed that consumption of alcoholic beverages and meat was greatly affected by household income fluctuations, whereas those of vegetables and dairy products were not sensitive to income. The impulse response functions indicated that expenditures not only increased slowly before peaking one to eight quarters after the income shock but declined very slowly to pre-shock levels. The response of dairy products at the twelfth step was three times as large as that of the first step.

• Korean Journal of Ecology and Environment
• /
• v.43 no.1
• /
• pp.24-34
• /
• 2010

This study was carried out to analyze some influences on ecological health conditions, threaten by various stressors such as physical, chemical and biological parameters. We collected samples in 2008 from three zones of upstream, midstream and downstream, Gap Stream. We applied multi-metric fish assessment index (MFAI), based on biotic integrity model to the three zones along with habitat evaluations based on Qualitative Habitat Evaluation Index (QHEI). We also examined fish fauna and compositions, and analyzed relations with MFAI values, QHEI values, and various guild types. Chemical parameters such as oragnic matter (BOD, COD), nutrients (TP, $NH_3$-N), coli-form number (as MPN), and suspended solids (SS) were analyzed to identify the relationship among multiple stressor effects. Using the sentinel species of Zacco platypus, the population structures and condition factors were analyzed along with DNA damages related with genotoxicant effects by comet assay. This study using all these parameters showed that stream condition was degraded along the longitudinal gradient from upstream to downstream, and the downstream, especially, was impacted by nutrient enrichment and toxicant exposure from the point source, wastewater treatment plant. Overall results indicated that our approaches applying various parameters may be used as a cause-effect technique in the stream health assessments and also used as a pre-warning tool for diagnosis of ecological degradation.

• KIEAE Journal
• /
• v.14 no.3
• /
• pp.121-126
• /
• 2014

Many cities in Japan retain older city structures with buildings in traditional form and style. Visitors are fascinated by charms and tranquility of pre-modern life styles. Architectural features of olden days are well conserved or carefully restored on purpose. In the case of Kawagoe city near Tokyo, local residents are largely replete with visitors without being necessarily aware of slow commodification of historic spaces. Kawagoe is yet socio-culturally sustainable and financially fit. This paper intends to analyse conservation strategies, with focus on architectural heritage, taken for the historic city of Kawagoe. With the population of 300,000 in the suburb of Tokyo, it is one of the best known historic cities in Japan. Kawagoe grew as a merchant city since 1700s, and it once reached to a major port of silk trade en-route to Edo (Tokyo) from northen provinces. Tourism industry is discovered as a key element in the conservation strategies applied to revitalize historic city center, Ichibangai, an important cultural heritage site with special reference to kurazukuri. This paper argues that augmentation of conceptions in architectural heritage is not only advantageous for the conservation of historic urban environment but it also provides opportunities for sustainable urban renewal.

• Journal of Korean Academy of Nursing
• /
• v.49 no.6
• /
• pp.771-782
• /
• 2019

Purpose: To determine the effects of a child and parent program on developing social skills for preventing violent behaviors in children aged 60~72 months through a specially developed pre and posttest, control group, quasi-experimental study. Methods: A social skills development program based on Gardner's Multiple Intelligence Theory was used. The data were collected using the Social Skills Assessment Scale (SSAS), a Chart to Monitor Verbal and Behavioral Violence in Children, the Parental Attitude Scale and the Parent Interview Form. This quasi-experimental study that included a pretest, posttest, and control group had a sample comprising 67 children and parents, with 36 in the experimental group, and 31 in the control group. Results: Over a six-month period, while the social skill scores of the children in the experimental and control groups increased, their violent behaviors decreased (p<.050). Increase in social skill scores and decrease in violent behaviors were higher in the experimental than in the control group children (p<.050). The parents in the experimental group stated that they had started to empathize with their children, using "I" language, and applied rules more consistently after the program. Conclusion: This program was successful in preventing violent behaviors in children through the development of social skills. Hence, it can be effectively implemented through a teacher/nurse collaboration.

• Smart Structures and Systems
• /
• v.16 no.3
• /
• pp.555-577
• /
• 2015

In the work at hand, the development of a morphing flap, actuated through shape memory alloy load bearing elements, is described. Moving from aerodynamic specifications, prescribing the morphed shape enhancing the aerodynamic efficiency of the flap, a suitable actuation architecture was identified, able to affect the curvature. Each rib of the flap was split into three elastic elements, namely "cells", connected each others in serial way and providing the bending stiffness to the structure. The edges of each cell are linked to SMA elements, whose contraction induces rotation onto the cell itself with an increase of the local curvature of the flap airfoil. The cells are made of two metallic plates crossing each others to form a characteristic "X" configuration; a good flexibility and an acceptable stress concentration level was obtained non connecting the plates onto the crossing zone. After identifying the main design parameters of the structure (i.e. plates relative angle, thickness and depth, SMA length, cross section and connections to the cell) an optimization was performed, with the scope of enhancing the achievable rotation of the cell, its ability in absorbing the external aerodynamic loads and, at the same time, containing the stress level and the weight. The conceptual scheme of the architecture was then reinterpreted in view of a practical realization of the prototype. Implementation issues (SMA - cells connection and cells relative rotation to compensate the impressed inflection assuring the SMA pre-load) were considered. Through a detailed FE model the prototype morphing performance were investigated in presence of the most severe load conditions.