• Journal of Korean Society of Environmental Engineers
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• v.28 no.5
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• pp.535-542
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• 2006

In this study, removals of 1-naphthol by oxidative-coupling reaction using birnessite, one of natural Mn oxides present in soil, was investigated in various experimental conditions(reaction time, Mn oxide loadings, pH, etc). Removal efficiency of 1-naphthol by birnessite was high in all the experimental conditions, and UV-vis. and mass spectrometric analyses on the supernatant after reaction confirmed that the reaction products were oligomers formed by oxidative-coupling reaction. Pseudo-first order rate constants, f, for the oxidative transformation of 1-naphthol by birnessite was derived from the kinetic experiments under various amount of birnessite loadings, and using the observed pseudo-first order rate constants with respect to birnessite loadings, surface area-normalized specific rate constant, $k_{surf}$ was also determined to be $9.31{\times}10^{-4}(L/m^2{\cdot}min)$ for 1-naphthol. In addition, the oxidative transformation of 1-naphthol was found to be dependent on solution pH, and the pseudo-first order rate constants were increased from 0.129 at pH 10 to 0.187 at pH 4.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.927-932
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• 2009

Toxic and recalcitrant organic pollutants in wastewaters can be effectively treated when advanced oxidation and biodegradation are combined, ideally with intimate coupling, in which both processes occur simultaneously in the same system. One means to achieve intimate coupling is to coat nanoscale $TiO_2$ on the outside of macroporous biofilm carriers. This study investigated the kinetics of photocatalysis with $TiO_2$-coated porous carriers. The carriers were made of polyvinyl alcohol (PVA) and coated with $TiO_2$ using a low-temperature sol-gel process. The $TiO_2$-coated carriers catalyzed the oxidation of methylene blue (MB) effectively under irradiation of UV light. The overall reaction rate with adsorption and photolysis saturated at high MB concentration, and approached the adsorption rate, which was first order for all MB concent rations. This result indicates that adsorbed MB may have slowed photocatalysis by blocking active sites for photocatalysis. The overall kinetics could be described by a quasi-Langmuir model. The estimated maximum specific (per unit mass of $TiO_2$) transformation rate of MB by the $TiO_2$-coated carriers was four times larger than that obtained from slurry-$TiO_2$ reactors. This observation demonstrated that the $TiO_2$ present as a coating on the carriers maintained high efficiency for transforming recalcitrant organic matter via photocatalysis. These findings serve as a foundation for advancement of an intimate coupling of photocatalysis to biodegradation.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.8
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• pp.592-597
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• 2013

It is widely known that the sound insulation of soundproof panel is highly correlated to two factors, surface density of material and the frequency of noise. Accordingly, the character of traffic noise released in actual situation is important requisite for determining thickness to determine surface density and material of soundproof panel. This present study selected polymer panel with advantage of light weight and workability and evaluates according to frequency of traffic noise. Polypropylene (PP) and high-density polyethylene (HDPE) were selected as subjects based on economic valuation and efficiency. The sound transmission loss of selected polymer panels were compared with the currently used panels such as polycarbonate (PC) and polymethyl methacrylate (PMMA) depending on thickness and materials. As a result, PC showed the highest sound transmission loss followed by PMMA, HDPE, and PP in range of mass law. In terms of acoustic performance on thickness, the transmission loss increased with thickness of soundproof panel meanwhile coincidence dip was observed in lower frequency where had reduced transmission loss. Therefore, it is suggested that after determining target frequency, the kind of materials and thickness of soundproof panel need to be designed so that traffic noise can be more efficiently reduced.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.4
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• pp.92-100
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• 2015

The aim of this study is to evaluate the fracture characteristics of ductile fiber reinforced cement based composites with 1.5 volume ratio of polyvinyl alcohol and steel fiber by high velocity impact of steel projectile. We used gunpowder impact facility to evaluate the fracture characteristics of ductile fiber reinforced cement based composites by collision of steel projectile, and the impact velocity was from about 150 to 1,000m/s. The results of evaluation on the fracture characteristics of ductile fiber reinforced cement based composites were penetration grade, which is the kinetic energy more than three times of no-fiber reinforced specimen (Plain). In addition, ductile fiber reinforced cement based composites did not occurred critical damage other than the debris. In the case of mass loss, Plain specimen was proportional to kinetic energy of steel projectile, while ductile fiber reinforced cement based composites was not significantly affected by kinetic energy of steel projectile. In particular, this tendency had a close relationship with the fracture characteristics of back side of specimens, and the scabbing inhibiting efficiency of PVA specimen was higher than S specimen. In the results of verifying relationship between front and back side calculated by local damage, scabbing occurred at the region close to the back side in the ductile fiber reinforced cement based composites unlike Plain specimen. Thus, in this study, we examined principal fracture behaviors of ductile fiber reinforced cement based composites under collision of steel projectile, and verified that impact resistance performance was improved as compared to Plain specimen.

• Korean journal of communication and information
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• v.46
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• pp.387-419
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• 2009

The concept of strategic group is defined as an aggregate of corporations utilizing similar strategies with similar resources. It becomes a kinds of contact point in the middle of corporation and industry between the industrial organization theory and the strategic management theory. This study tried to apply the strategic group model, which has been a main theory in the management studies, to program providing industry in Korea. This study shed lights upon research problems such as number of strategic groups, differences of strategic variables among the groups, finally differential performances according to strategic groups. 40 commercial broadcasting companies were analyzed to find answers. 9 strategic groups were drawn as a result of cluster analysis. Major variables which contribute to making groups were operating efficiency(4.05), pricing(3.83), size(number of system operator, 3.56), reliance on license revenue(2.58), horizontal integration(number of sister networks, 2.16) in order. An analysis of variance between performance variables has shown statistical significance regarding total net revenue per subscriber, however, insignificances statistically in regards to ratio of operating profit to net sales, cash Abstracts 687 flow ratio. Some studies in the past insisted that history variable played an important role to classifying strategic groups. However, this study found that the history didn't exert significant influence on either the group classification itself or performance.

• Journal of Acupuncture Research
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• v.22 no.3
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• pp.77-92
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• 2005

Objective : The aim of the study was to investigate the effect of Acanthopanax senticocus(AS) herbal acupuncture on the metabolic syndrome in high-fat diet fed mice. Methods : ICR mice were fed with high-fat diet to induce the metabolic syndrome. During the inducement of the metabolic syndrome, the groups were treated with AS herbal acupuncture with different concentrations(125mg/kg, 250mg/kg and 500mg/kg) to the point of Sinsu(BL23) everyday for 5 weeks. Thereafter, body weight, feed efficiency ratio, blood pressure, blood glucose, insulin level, insulin resistance, oral glucose tolerance test(OGTT), lipid profile(TG, TC, HDL-C, LDL-C, NEFA), mass of liver, histology of white adipose tissue(WAT) and brown adipose tissue(BAT), and expression of GLUT-4 and UCP-1 mRNA were measured. Results : The risk factors of metabolic syndrome such as obesity, non-insulin dependent diabetes mellitus(NIDDM), insulin resistance, hypertension, dyslipidemia were aggravated by high-fat diet for 5-weeks. AS herbal acupuncture inhibited the development of weight gain, hyperglycemia, hyperinsulinemia, insulin resistance, hypertension, dylipidemia and expression of GLUT-4 in WAT and UCP-1 mRNA in BAT, and also improved oral glucose intolerance and distribution of adipose tissue.

• Journal of Korean Public Health Nursing
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• v.14 no.2
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• pp.431-445
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• 2000

In general the prevalence of old people is high and frequently have multiple diseases and symtoms requiring treatment. The nature of illness in the elderly has to be faced, and drugs do have an important part in the treatment of that illness. The purpose of this study were to describe health status and medication, and to provide some basic data for elderly's health education, especially for the right medication. Body mass index, self perceived health status, activities of daily living, disease and experience of past operation were surveyed to recognize the 249 elderly's actual health status. The degree of the elderly's understanding the way of medication, experience of side effects, experience of drug combination and incidence of drug adverse reaction along with drug combination were examined for medication. The aged $women(BMI; 10.7\pm13.3\%)$ overweighed the aged $men(BMI; 4.0\pm10.4\%)$. $69.0\%$ of them recognized their health good. Their activities of daily living were diminished following by the age group(p=0.0068) and relationship with self perceived health status were very significant(p=0.0005). They(192 elderly) suffered from multiple disease such as $osteoarthritis(49.5\%)$, $hypertension(32.0\%)$, gastric $disorder(16.1%)$, $diabetes(14.6\%)$, $osteomalacia(10.9\%)$, cardiovascular $disease(9.9\%)$, senile $cataract(5.7\%)$, skin $rash(5.2\%)$, liver $disease(4.2\%)$, kidney $disease(3.6\%)$, spinal cord $problem(3.6\%)$, respiratory $disease(2.1\%)$ $tuberculosis(1.0\%)\;etc(1.0\%).$ $28.3\%$ of them replied that they had an operation for appendictis senile cataract, peptic ulcer, spinal cord problem, pleurisy, hemorrhoid and the rest. Most of $them(87.4\%)$ knew the way very well how to use drugs, and $21.6\%$ of the replied 171 elderly experienced adverse drug reaction. Drug compliance rate were $high(83.6\%)$. In our study 56.9% of the 167 elderly took several medicine together. And $18.9\%$ of the 95 elderly who did drug combination had an experience of drug interaction. One person kept average 5.5 kinds of drugs at home among 243 elderly. They kept $digestives(79.4\%)$, $ointments(68.7\%)$, $vitamins(59.7\%)$, $analgesics(59.7\%)$, cold $medicines(45.3\%)$ antiarthritic $drugs(33.3\%)$, health $foods(27.7\%)$, antihypertensive $drugs(25.1\%)$, anti peptic ulcer $drugs(24.7\%)$, $laxatives(19.8\%)$, $antacids(16.5\%),\;antibiotics(l6.5\%)$, hypoglycemic $agents(10.3\%)$, cardiac $stimulants(7.0\%)$, $diuretics(4.5\%)$, antiarrhythmic $drugs(4.9\%)$, anti anginal $drugs(4.1\%)$, $hypnotics(3.3\%)$, $etc(38.3\%)$. With this result, we ascertain that polypharmacy in the elderly caused by multiple disease is common, which lead to drug interaction. So our task is to educate elderly how to use drugs in order to maximize their efficiency and to minimize their adverse effects.

• Journal of Environmental Science International
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• v.6 no.3
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• pp.267-276
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• 1997

It has been studded that combustion and the production of air pollution of anthracite - bituminous coal blend In a fluidized bed coal combustor, The objects of thIns study were to investigate mixing characteristics of the particles as well as the combustibility of the low grade domestic anthracite coal and Imported h19h calorific bltununous coal in the fluidized bed coal combustor. They were used as coal samples ; the domestic low grade anthracite coal with heating value of 2,010kca1/kg and the Imported high grade bituminous coal with beating value of 6,520kca1/kg. Also, the effects of air flow rate and anthracite fraction on the reaching time of steady state condition have been studied. The experimental results are presented as follows. The time of reaching to steady state was affected by the temperature variation. The steady state time was about 120 minute at 300sc1h which was the fastest. It has been found that $O^2$ and $CO^2$ concentration were reached steady state at about 100 minute. It has been found that $O^2$ concentration decreased and $CO^2$ concentration increased as the height of fluidlzed bed Increased. It was found that splash zone was mainly located from 25cm to 35cm above distributor. Also, as anthracite traction Increased, the mass of elutrlatlon particles Increased, and $CO^2$ concentration decreased. As gk flow rate Increased,$O^2$ concentration decreased and $CO^2$ concentration increased. Regardless of anthracite fraction and flow rate, the uncombustible weight percentage according to average diameter of elutriation particles were approldmately high In the case of One Particles. As anthracite traction and k now rate Increased, elutriation ratio Increased. As anthracite fraction was increased, exit combustible content over feeding combustible content was Increased. Regardless of anthracite fraction, size distribution of Ued material from discharge was almost constant. Over bed temperature 85$0^{\circ}C$ and excess air 20% , the difference of combution efficiencies were little. It is estimate that the combustion condition In anthracite-bituminous coal blend combustion is suitable at the velocity 0.3m/s, bed temperature 85$0^{\circ}C$, the excess air 20%.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.3
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• pp.265-273
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• 2000

Purpose : The aim of this study was to evaluate the bone mineral density of iliac and tibial bone which are frequently selected as autogenic bone graft donor sites, and to evaluate the efficiency of this method as a guideline for the selection of bone graft donor site. Materials and Methods : In this study 61 male and 70 female volunteers at Chungbuk National University Hospital were involved between Jan. 1998 to Sept. 1999. We measured bone mineral density of the iliac and the tibial bone using dual energy X-ray absorptiometry. We evaluated the data using the SAS system for Windows and bone mineral density of the lumbar was used for control. Results : Age showed the highest correlation in correlation matrix between physical and bone variables. Height and weight showed lower correlation of linear increment. In man, the change of bone density according to age demonstrated linear decrease irrespective of the lumbar, ilium, and tibia. In woman, the change of bone density according to age showed cubic form, which increased in the third and forth decade. So it had a peak bone mass on about 35 year-old, thereafter, the change of bone density slowly decreased until 50 year-old, but it rapidly decreased after 50 year-old and it slowly decreased again after 65 year-old. Both in all subjects and subject with osteoporosis, the change of bone mineral density according to age showed statistically significant decrease in lumbar and tibia, but ilium was irrespective. Conclusion : In patients of aged or with osteoporosis, ilium demonstrated less tendency of decrease in bone mineral density than tibia. So this preliminary study suggested that ilium seemed better donor site for autogenic bone graft than tibia.

• Journal of Korean Medicine for Obesity Research
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• v.15 no.1
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• pp.9-23
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• 2015

Objectives: This study was investigated the improvement effects of Pakistani Ephedra herba-containing Gangji-hwan-1, 2, 3 (Di-fatty; DF-1, 2, 3), Chinese Ephedra herba-containing Gangjihwan-4 (DF-4) and combination of DF-1 and Gamisoche-hwan (GSH) on obesity in a high fat diet-fed obese mouse model. Methods: Eight-week-old C57BL/6N mice were divided into seven groups: a normal lean group given a standard diet, an obese control group given a high fat diet, and DF-1, 2, 3, 4, and DF-1+GSH groups given a high fat diet with DF-1, 2, 3, 4 (40, 80, 160, 80 mg/kg), and DF-1+ GSH (80 mg/kg), respectively. After 8 weeks of treatment, body weight gain, feeding efficiency ratio (FER), blood lipid markers, liver histology, and fat weight and histology were examined. Results: Body weight gain was significantly decreased in DF and DF-1+GSH groups compared with control. The extent of decreases was eminent in DF-1+GSH group. FER and circulating concentration of leptin were decreased in DF and DF-1+GSH groups compared with control. Circulating concentrations of triglyceride, glucose and insulin were decreased in DF and DF-1+GSH groups compared with control. The size of adipocytes were decreased by DF and DF-1+GSH groups compared with control, whereas the adipocyte number per unit area was increased by them, suggesting that DF and DF-1+GSH groups decreased the number of large adipocytes. Conclusions: In conclusion, these results suggest that DF and DF-1+GSH groups decrease FER, plasma leptin concentration, blood anti-obesity biomarkers and fat mass, improves body weight gain. In addition, these effects were more effective in DF-1+GSH combination group than in DF-1, 2, 3, 4 groups.