• 도시과학
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• 제8권2호
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• pp.29-34
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• 2019

Benzene pollution is becoming increasingly serious, and the treatment technology of benzene has attracted much attention. In this paper, a self-made photocatalytic reactor was used to explore the removal rate of benzene under the ultraviolet light with the wavelength of 253.7nm. The results showed that the degradation rate of benzene decreased from 64.29% to 16.26% when the concentration increased from 43mg/㎥ to 256mg/㎥ under the condition of 28W UV light intensity and 50s residence time. Under the condition of 28W UV light intensity and 103mg/㎥ concentration, the residence time increased from 16.5s to 50s, and the benzene removal rate increased from 13.23% to 42.72%.Under the condition of benzene concentration 103mg/㎥ and residence time of 50s, the removal rate of benzene increased from 29.34% to 52.58% in the process of UV light intensity rising from 28W to 48W.It is concluded that decreasing the concentration and increasing the residence time of gas were beneficial to the removal of benzene and increasing the light intensity can improve the removal rate of benzene.

• 패션비즈니스
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• 제9권6호
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• pp.29-38
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• 2005

Natural dyes have attracted the worldwide attention because of its environmental advantage over synthetic dyes. However, most of natural dyes are expensive for mass production, strongly season and source dependent, and hard to store. In this study, coffee waste were used as natural dye to create beautiful colors. Coffee waste is inexpensive and easy to store, and provides a comparatively regular quality regardless of seasonand source. The effects of mordant agent concentration and mordanting temperature on dyeing efficiency of silk fabrics were investigated. Coffee extract dyed silk showed brilliant colors, and the colors were different with the kind of mordants. Cu, Sn, and Al mordanted silks showed golden yellow with subtle change of hue and value, while Fe mordanted silk showed a brownish green color. The increase in mordant concentration did not always increase the dyeability, and 0.5% o.w.f. mordant concentration was enough to get a satifactory result. Mordanting temperature also had little effect on the dyeability in case of Al, Cu, and Sn mordanted fabrics. Only Fe mordanted fabrics showed a better dyeability in the increase in mordating temperature. Coffee extract dyeing is an effective way using waste as resource and can create brilliant colors with minimal amount of mordant and under mild mordanting condition.

• Journal of Yeungnam Medical Science
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• 제36권1호
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• pp.50-53
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• 2019

Awareness during general anesthesia occurs in approximately 0.1-0.2% of cases; nevertheless, particular attention is required because it can lead to critical complications including insomnia, depression, anxiety, and post-traumatic stress disorder. To prevent these complications, bispectral index (BIS) and end-tidal anesthetic gas (ETAG) concentration monitoring are commonly used to examine patient consciousness during surgery. In the present case, an 80-year-old man was scheduled for total gastrectomy. Anesthesia was maintained using desflurane 4.0-5.0% vol, oxygen, and nitrous oxide. The authors simultaneously monitored BIS, which was maintained between 37 and 43, and ETAG, which was maintained between 0.9 and 1.2 minimum alveolar concentration (MAC). After the operation, however, the authors were surprised to learn that the patient complained of awareness during anesthesia. Although BIS and ETAG concentration monitoring are useful in preventing awareness during anesthesia, they cannot be completely trusted. Even though BIS was maintained at approximately 40 and ETAG at 0.7-1.3 MAC, awareness during anesthesia occurred.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.208.2-208.2
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• 2016

Many researchers have paid attention to the studies on the interaction between non-thermal plasma and aqueous solutions for biomedical applications. The gas composition in the plasma is very important. Oxygen and nitrogen are the main gases of interest in biological applications. Especially, we focus on the oxygen concentration. In this experiment, we studied the role of oxygen concentration in plasma induced chemical reactions in solution. At first, the amount of ions are measured according to changing the oxygen concentration. And we checked the relationship between these ions and pH value. Secondly, when the oxygen concentration is changed, it identified the type and amount of radical generated by the plasma. In order to confirm the effect of these chemical property change to biological material, hemoglobin and RBCs are chosen. RBCs are one of the common basic biological cells. Thirdly, when plasma treated according to oxygen concentration in nitrogen feeding gas, oxidation of hemoglobin and RBC is checked. Finally, membrane oxidation of RBC is measured to examine the relation between hemoglobin oxidation and membrane damage through relative hemolysis and Young's modulus. Our results suggest that reactive species generated by the plasma differsdepending on the oxygen concentration changes. The pH values are decreased when oxygen concentration increased. OH decrease and NO increase are also observed. These reactive species makes change of chemical properties of solution. We also able to confirm that the difference in these reactive species to affect the oxidation of the Hb and RBCs. The Hb and RBCs are more oxidized with the high oxygen concentration conditions. But membrane is damaged more by plasma treatment with only nitrogen gas. It is shown that red blood cells membrane damage and oxidation of hemoglobin are not directly related.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제25권1호
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• pp.28-36
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• 2014

Objectives : The goal of this study was to examine the association between zinc and lead level and symptoms of attention-deficit hyperactivity disorder (ADHD) among Korean children. Methods : A total of 89 clinic-referred children participated in the study (ADHD group=45, control group=44). The participants were 5-15 years old, and were mainly from urban areas of Seoul, Korea. ADHD was diagnosed using the Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version. We excluded children with a comorbid psychiatric disorder, medical illness requiring medication, or a prior history of taking ADHD medication. In order to evaluate the severity of ADHD symptoms, parents' Korean ADHD Rating Scale (K-ARS) was used. The ADHD diagnostic system (ADS) was used for evaluation of the severity of inattention and impulsivity. All participants completed the intelligence test and hair mineral analysis. Multiple regression analysis was used to examine the effect of hair zinc and lead levels on the K-ARS and ADS. We measured the predictive ability of the zinc and lead levels using logistic regression analysis. Results : The lead level explained the score for omission errors, commission errors, and response time SD in visual ADS in the ADHD group (adjusted $R^2$=.243, p<.01, adjusted $R^2$=.362, p<.01, and adjusted $R^2$=.275, p<.01), the score for omission errors of auditory ADS in ADHD group (adjusted $R^2$=.407, p<.01) and the entire group (adjusted $R^2$=.292, p<.01). Zinc was significantly explanatory for the K-ARS scores for the entire group (adjusted $R^2$=.248, p<.001) and the ADHD group (adjusted $R^2$=.247, p<.05). Conclusion : These findings suggest a possible role of zinc and lead in ADHD. Lead concentration in hair samples affected the ADS scores, and this was more prominent in children with ADHD. Children with ADHD had a lower zinc concentration in their hair, and the zinc concentration in hair showed negative correlation with the K-ARS score.

• Environmental Analysis Health and Toxicology
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• 제9권3_4호
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• pp.91-101
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• 1994

In order to evaluate the ecotoxicological harzardousness of synthetic surfactants on Han river, Jung-ryang and Jin-Wi stream, we used the Ecotoxicological Risk Quotient (ERQ). The chemical harzardousness is evaluated by the balance of the toxicity and concentration in the environment.. Then, ERQ is defined as follows; ERQ = - log ( Concentration in the environment / Effective concentration in the test ) ERQ of chemical is a logtrighmic value of ratio of a chemical concentration and the toxicity in the laboratory. In case of small ERQ, tie chemical harzardousness is high. If ERQ equals O, the same biological effect as in the laboratory test will be observed in the enviromment by the chemicals. ERQ values of the chemicals were calculated using the maximum concentration in water environment which were cited from the annual report by our ministry of environment, and EC$_{50}$ of Daphnia magna (water flea; acute immobilization test) LC$_{50}$ of Oryzias latipes (fish; acue toxicity test) and EC$_{50}$ of chlorella vulgaris (alga; growth inhibition test), which were taken from the annual report of "Chemical in environment" by Japan EA. Liner alkylbenzene sulfonate (determined to MBAS) showed the high average values with more than 2.0 to three species in Han river and Jin-wi stream, and these results mean to be favorable to environmental safety. The areas of Jung-ryang stream were polluted, as the average values of ERQ were less than 2.0 with equal to three species, and attention should be paid. Therefore, they must be inspected again because their concentration in the environment may have changed during that period. The chemical harzardousness can be numerated with ERQ, and it can be a help to find the chemicals that should be kept under observation and to see whether the chemical pollution is improved or worsened. The determination of the chemical concentration in the environment and toxicity are essential for the effective use of ERQ.se of ERQ.

• The Korean Journal of Ceramics
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• 제5권1호
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• pp.35-39
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• 1999

For many years, alkali activated blast furnace slag cement containing no ordinary portland cement has received much attention in the view of energy saving and its many excellent properties. We examined the structural change of slag glass which was activated by alkali metal compounds using IR spectroscopy. The properties of hydrated products and unhydrated slag grains was characterized by XRD and micro-conduction calorimeter. Ion concentration change in the liquid during the hydration of blast furnace slag was also studied to investigated the hydration mechanism.

• 한국식품저장유통학회지
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• 제4권2호
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• pp.215-225
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• 1997

The review was conducted to organize the desirable salting process from the literatures. In this study the principle of salting and effects of physicochemical changes in salting and salting factors such as cultivars of baechu(Chinese cabbage), concentration of salt, salting temperature, pH condition for salting and quality of kimchi were studied. The method of salting standard, treatment techniques in salting, and selection and mixture ratio of sub-ingredients were also reviewed. In future studies greater attention should be paid to salting and fermentation of kimchi.

• Journal of Magnetics
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• 제2권2호
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• pp.58-66
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• 1997

Recently, artificially modulated magnetic multilayer materials, for examples giant magnetoresistant magnetic head materials and magneto-optic recording materials in the wavelength of a blue laser beam, attract great attention in the electronics industry due to their unique properties derived from the modulated multilayer structure. Since the multilayer structure as well as amorphous structure, is non-equilibrium state in terms of free energy, an assessment of the thermal staibility in the multilayer structure is crucially importnat both for basic research and applications. In this review paper, effective microscopic interdiffusion process in the two dimensional multilayer structure will be described in terms of steep concentration gradient effect, strain effect and magnetic transition effect.

• 미생물학회지
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• 제26권2호
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• pp.93-100
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• 1988

In order to understand the regulation of glutamate dehydrogenase(GDH) synthesis in Brevibacterium flavum, we have isolated a mutant lacking NADP-linked GDH activity by ethlmethane sulfonate treatment. The $gdh^-$ mutant was grown on the minimal plate with 1mM ammonium chloride and not that with 300mM ammonium chloride. The cell-free extracts from $gdh^-$ mutant and prototroph were also examined with glutamine synthetase(GS) and glutamate synthase (GOGAT) production by niteogen sources. The growth of $gdh^-$ mutant in presence of 20mM ammonium chloride means that GOGAT synthesis is sufficient to allow growth in this condition. GS production of $gdh^-$ mutant as well as parental strain was induced by 1mM urea and ammonium tartrate, but it was repressed by higher concentration of ammonia, and also induced by 20mM to 50mM glutamate as a substrate. It was special attention that GOGAT synthesis from $gdh^-$ strain was more repressed by higher concentration of ammonia than prototroph as described in E. coli system.