• Journal of the Korean Chemical Society
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• v.29 no.1
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• pp.52-60
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• 1985

Oxides of nitrogen (NO$_x$) in exhaust gases was determined by absorbing the gas in alkaline peroxide solution containing 0.03${\%}$ H2O2 and 0.1N NaOH. About 100 ppm of NO$_x$ was rapidly oxidized to NO$_2$ or N$_2$O$_5$ by H$_2$O$_2$ and required a contact time of 2 minutes with the absorbing solution for complete absorption. With vigorous shaking including air or oxygen gas, high concentration of NO$_x$ (>200 ppm) can be absorbed within 30 minutes. The remaining H$_2$O$_2$ affect the absorbance of color solution strongly. However, the excess H$_2$O$_2$ was completely decomposed by zinc powder 0.5g and the sample solution should be adjusted to the pH range 6.1∼6.6 before the reduction so that conversion of nitrate to nitrite ion is possible. The absorbed NO$_x$ is determined colorimetrically by the diazotization-coupling method with sulfonilamide and NEDA as the coupling agent. The sensitivity of the new method was 4.48 ${\times}$ 10$^4$ as molar absorptivity which was high sensitive compared with that obtained for the usual zinc reduction NEDA method with O$_3$. This method was far more rapid, brief and accurate than previously published O$_3$-NEDA method in Korean industrial standard.

• Journal of Environmental Health Sciences
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• v.33 no.1 s.94
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• pp.36-42
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• 2007

Diesel PM can be controlled using Diesel Particulate Filter, which can effectively reduce the level of soot emissions to ambient background levels. In the Heavy Duty Diesel area, the Continuously Regeneration trap has been widely applied in the retrofit market. As the Special act for the improvement of air quality in the capital area, the retrofit program for DPF to used diesel vehicle has progressed favorably and there are currently over 1,000 of these DPF in use in retrofit applications in korea. These DPF comprise a specially formulated Diesel Oxidation Catalyst upstream of a DPF. The $NO_2$ generated by the DOC is used to combust the carbon collected in the DPF at low temperature. To certificate DPF device that is suitable to domestic circumstances, it is necessary to evaluate exactly the DPF devices according to the regulation of DPF certificate test procedure for retrofit(ministry of environment(MOE) announcement NO. 2005-16). To do so the understand of that regulation like the standard of PM reduction rate is needed. In this study the test procedure including test cycle and BPT test condition was examined and also the test result for specific DPF was analyzed. In every test like field test, PM reduction efficiency test and seoul-10 mode test, no defect could be showed.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.40.1-40.5
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• 2020

Background: Hyaluronic acid (HA) is well known to exert an anti-inflammatory effect during oral wound healing and is commonly applied after tooth extraction. However, no double-blind randomized controlled study comparing two hyaluronate mouthwash products has been conducted so far. The aim of this study was to comparatively analyze the efficacy of Mucobarrier^® and Aloclair^® in terms of clinical symptoms. Results: A total of 112 patients were randomly assigned to assess the degree of discomfort, pain reduction, redness, burning sensation, and swelling between two groups on the day of surgery and 7 days later in a double blind test, with a total 56 Aloclair patients and 56 Mucobarrier patients. There was no statistically significant difference in the overall discomfort, degree of pain reduction, redness, burning sensation, and swelling between the Mucobarrier and Aloclair groups. Conclusion: The local application of hyaluronic acid mouth wash after wisdom tooth extraction is beneficial in reducing overall discomfort and pain reduction, and the clinical utility of Mucobarrier^® is no different from Aloclair^®. Trial registration: Institutional Review Board of Yonsei University College of Dentistry, 2-2018-0036. Registered 10 September 2018-prospectively registered, https://eirb.yuhs.ac/

• Korean Journal of Acupuncture
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• v.20 no.2
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• pp.93-100
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• 2003

Effects of Wisoo and Baekwhe acupuncture on serum glucose and lipid composition were investigated in high fat diet induced diabetic rat. Plasma glucose, free fatty acids and $\Beta-lipoprotein$ concentration showed a high reduction in wisoo acupuncture group compared to those of control group, however the values of baekwhe acupuncture group showed no significantly different those of control group. Plasma triglyceride and LDL-cholesterol concentration showed a tendency to decrease in the wisoo acupuncture groups, however the values of baekwhe showed no significantly different those of control group. Total cholesterol concentration showed a high reduction in wisoo acupuncture groups and HDL-cholesterol concentration showed a high values in wisoo acupuncture group, however these values no significantly different in all treatment groups.

• PNF and Movement
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• v.8 no.1
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• pp.21-29
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• 2010

Purpose : The purpose of this research is to examine the effects of circuit weight training and aerobic exercise on the bodily formation and abdominal fat area of obese female college students. Methods : The female college students whose BMI is over $25kg/m^2$ were divided into the circuit weight training group and the aerobic exercise group and circuit weight training and aerobic exercise were conducted on the respective group five times a week. Resultlts : 1. The tendency of statistically significant reduction in weight, body fat percentage, and BMI was shown in both the circuit weight training group and the aerobic exercise group but there were no significant differences between these groups. 2. The tendency of statistically significant reduction in total abdominal fat area, and subcutaneous fat area was shown in both the circuit weight training group and the aerobic exercise group but there were no significant differences between these groups. 3. Visceral fat area was reduced more in the aerobic exercise group than in the circuit weight training group Conclusion : It was confirmed that exercise alone in the state of no dietary treatment being given could cause obese people bodily formation.

• Archives of Craniofacial Surgery
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• v.10 no.2
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• pp.76-80
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• 2009

Purpose: Zygoma is a major portion of the midfacial skeleton, forms the malar prominence and the three adjacent bony articulations. Zygoma fracture is a very common in facial trauma. Open reduction and rigid fixation of displaced zygoma fractures are necessary to avoid immediate and delayed facial asymmetry and depression. However, it is possible to happen the complications related to the plates and screws. So, we planned to treat the 24 patients of Group II, III, IV zygoma fractures with precise reduction and non-fixation method via intraoral approach. Methods: From August, 2006, to August, 2009, we treated 24 cases of zygoma fracture with reduction and non-fixation methods. Before the surgery, we choose the patients who could be treated with this method among the Group II, III, IV patients. Results: No patients in this study had postoperative complications such as displacement of bony fragments, facial depression and asymmetry, malocclusion, hypoesthesia. Satisfactory aesthetic and functional results can be obtained. Conclusion: In the treatment of the zygoma fracture, it is possible to treat with precise reduction and non-fixation method. The greatest advantage is to decrease the operative time, no need to wide dissection, no complications related to the plates and screws. For the using of this method, it is necessary to choose the adequate patients through the preoperative planning.

• 한국연소학회:학술대회논문집
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• 2000.12a
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• pp.33-46
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• 2000

In the present study, a systematic chemical kinetic calculations were made to investigate the augmentation of NO-$NO_2$ conversion due to the addition of various hydrocarbons (methane, ethylene, ethane, propene, propane) in the nonthermal plasma treatment. It is included in the present conclusion that the reaction between hydrocarbon and oxygen radicals induced by electron collision, is believed to be a primarily process for triggering the overall NO oxidation and the eventual NOx reduction. Upon the completion of the initiating step, various radicals (OH, $NO_2$ etc.) successively produced by hydrocarbon decomposition form the primary path of NO-$NO_2$ conversion. When the initiating step is not activated, hydrocarbon consumption rate appeared to be very low, thereby the targeted level of NO conversion can only be achieved by the addition of more input energy. Present study showed ethylene and propene to have higher affinity with 0 radical under all conditions, thereby both of these hydrocarbons show very fast and efficient NO-$NO_2$ oxidation. It was also shown that propene is superior to ethylene in the aspect of NOx removal.

• Journal of Industrial Technology
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• v.19
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• pp.331-341
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• 1999

We analyzed theoretically the removal efficiency and the particle growth inside the pulse corona discharge reactor to remove $NO_x$ and investigated the effects of process variables such as the NO and $NH_3$ input concentrations. Most of NO is converted into $NO_2$ and $HNO_3$ and the $HNO_3$ reacts with $NH_3$ to form the $NH_4NO_3$ particles. About 6.4% of NO is converted into $HNO_2$ which form the $NH_4NO_2$ particles by reaction with $NH_3$. Some of $NO_2$ follows the reaction pathway to form $NO_3$ and $N_2O_5$. The amount of particles formed inside the reactor is basically determined by the input $NH_3$ concentration. The ratio of NO to $NH_3$ affects the reactor length for particle formation significantly. The higher the input concentrations of NO and $NH_3$ are, the faster the particles grow.

• Journal of Microbiology and Biotechnology
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• v.20 no.3
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• pp.615-621
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• 2010

The viability of low-temperature sulfate reduction with hydrogen as electron donor was studied with a bench-scale gas-lift bioreactor (GLB) operated at $9^{\circ}C$. Prior to the GLB experiment, the temperature range of sulfate reduction of the inoculum was assayed. The results of the temperature gradient assay indicated that the inoculum was a psychrotolerant mesophilic enrichment culture that had an optimal temperature for sulfate reduction of $31^{\circ}C$, and minimum and maximum temperatures of $7^{\circ}C$ and $41^{\circ}C$, respectively. In the GLB experiment at $9^{\circ}C$, a sulfate reduction rate of 500-600 mg $l^{-1}d^{-1}$, corresponding to a specific activity of 173 mg ${SO_4}^{2-}g\;VSS^{-1}d^{-1}$, was obtained. The electron flow from the consumed $H_2$-gas to sulfate reduction varied between 27% and 52%, whereas the electron flow to acetate production decreased steadily from 15% to 5%. No methane was produced. Acetate was produced from $CO_2$ and $H_2$ by homoacetogenic bacteria. Acetate supported the growth of some heterotrophic sulfate-reducing bacteria. The sulfate reduction rate in the GLB was limited by the slow biomass growth rate at $9^{\circ}C$ and low biomass retention in the reactor. Nevertheless, this study demonstrated the potential sulfate reduction rate of psychrotolerant sulfate-reducing mesophiles at suboptimal temperature.

• Journal of Wellbeing Management and Applied Psychology
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• v.6 no.2
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• pp.39-46
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• 2023

Purpose: The small-scale environmental impact assessment system in Korea was introduced and implemented in August 2000, but it has a problem that it cannot guarantee implementation due to the large proportion of qualitative reduction measures for each evaluation item. Therefore, when preparing a small-scale environmental impact assessment, research was conducted on how to improve the existing simple listing-type reduction measures and qualitative evaluation standards to quantitative reduction measures and evaluation standards reflecting regional characteristics. Research design, data and methodology: The small-scale environmental impact assessment system in Korea was introduced and implemented in August 2000, but it has a problem that it cannot guarantee implementation due to the large proportion of qualitative reduction measures for each evaluation item. Therefore, when preparing a small-scale environmental impact assessment, research was conducted on how to improve the existing simple listing-type reduction measures and qualitative evaluation standards to quantitative reduction measures and evaluation standards reflecting regional characteristics. Results: As a result of the analysis of qualitative and quantitative factors, the arithmetic sum of the qualitative factors of the total six projects is 160, accounting for 80% of the total number of reduction measures, and the quantitative factors are 40, accounting for 20%. Among them, the number of qualitative reduction measures reached 97.4% for animal and plant items, and more than 90% for air quality, noise and vibration, and eco-friendly resource circulation items. Conclusions: Therefore, it is necessary to avoid establishing qualitative reduction measures and set quantitative measures as the basis, but to specify the specifications, size, and installation location related to the reduction measures, and to calculate the numerical reduction efficiency.