• Title/Summary/Keyword: $NO_2$ reduction

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Efficiency of the Hybrid-type Air Purifier on Reducing Physical and Biological Aerosol (복합식 공기청정기의 물리적 및 생물학적 입자상 물질의 제거 효과)

  • Kim, Ki-Youn;Kim, Chi-Nyon;Kim, Yoon-Shin;Roh, Young-Man;Lee, Cheol-Min
    • Journal of Environmental Health Sciences
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    • v.32 no.5 s.92
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    • pp.478-484
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    • 2006
  • There was no significant difference in the CADR (Clean Air Delivery Rate) between physical aerosols, NaCl and smoke, and biological aerosols, airborne MS2 virus and P. fluorescens, which implicate that the hybrid-type of air purifier, applying the unipolar ion emission and the radiant catalytic ionization, imposed identical reduction effect on both physical aerosol and bioaerosol. Ventilation decreases the efficiency of air cleaning by unipolar ionization because high ventilation diminishes the particle concentration reduction effect. The particle removal efficiency decreases with increase in the chamber volume because of the augmented ion diffusion and higher ion wall loss rate. Particle size affects the efficiency of air ionization. The efficiency is high for particles with very small diameter because reduction of charge increases with particle size. If there is no increasing supply of ions, the efficiency of air cleaning by unipolar ionization increases with respect to initial concentration of particles because of the large space charge effect at high particle concentration and amplified electric field.

The Effects of Combined Obesity Management Program on Blood Lipids and Dietary Habit in Obese Women (통합비만관리 프로그램이 여성의 혈중 지질대사 및 식습관 양상에 미치는 영향)

  • Kim, Young-Hee
    • Korean Parent-Child Health Journal
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    • v.10 no.1
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    • pp.65-76
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    • 2007
  • Purpose: This study was to determine the effects of a combined obesity management program in obese women. The study also attempted to measure the effects of the program on blood lipid, body mass index, dietary calory and dietary habit. Method: This research employed a one group pretest-posttest design. A total of 251 obese women(BMI: over 25) were selected for this research. The subjects in a combined obesity management program (combined exercise therapy and dietary therapy) for 8weeks. Results: After performing the program for 8 weeks, the result were follows. 1) There were significant reduction in total cholesterol(t=4.10, p= .00), triglyceride(t=5.09, p= .00) but no significant reduction BMI. 2) There were reduction in dietary calory, but no significantly. 3) There were significant increase in dietary habit. Conclusion: From these findings, it was confirmed that a combined obesity management program for obese women can decrease TC, TG, BMI and increase dietary habit. Therefore, this program can be utilized for various population groups including women, and further researches are required on program for men, elderly.

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An Empirical Study on the Influencing Factors of Chinese Consumers' Impulse Buying Behavior During Online Shopping Festivals after COVID 19 - focused on the Meditating Role of Perceived Value (COVID-19 이후 온라인쇼핑 축제기간 중국 소비자의 충동구매행태 영향요인에 관한 실증연구-인식된 가치의 매개 역할을 중심으로)

  • Xu Kai;Woohyoung Kim;Yongseok Cho
    • Korea Trade Review
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    • v.46 no.6
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    • pp.163-190
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    • 2021
  • The paper studies the impulse buying behavior of Chinese consumers during the online shopping festivals of the specific situations and their influencing factors with empirical analysis. We carried out an empirical analysis on 302 Chinese consumers with shopping experience in the online shopping festival. The study result shows that (1) marketing stimulation, preferential promotion and features of consumers have a significant positive influence on the impulse buying behavior; while the freight reduction has no significant influence on impulse buying behavior; (2) the perceived value has a significant positive influence on the Chinese consumers to have impulse buying behavior; (3) perceived value works as an in the relationship between the marketing stimulation, preferential promotion and features of consumers and the impulse buying behavior, but it has no meditating role between the freight reduction and the impulse buying behavior.

Development and Analysing the Practical Use of Bleeding Reduction Agent for Concrete (콘크리트용 블리딩저감제의 개발 및 실용성 검토)

  • Han, Cheon-Goo;Hwang, Yin-Seong;Shin, Dong-In
    • Journal of the Korea Concrete Institute
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    • v.15 no.2
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    • pp.217-224
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    • 2003
  • It is necessary to reduce bleeding, which is a kind of segregation of fresh concrete, for improvement of quality of concrete structure. But, besides using high qualify material and adjusting mixture ratio, there is no easy solution to reduce bleeding by now. For that reason, this study is intended to develop bleeding reduction agent and to investigate its application. The test results are following. At first, recommended mixture ratio of bleeding reduction agent is proven to be MC viscosity agent : defoaming agent : superplasticyzer of 1 : 0.004 : 0.2. It goes to prove that bleeding reduction agent does not have bad effect on the quality of concrete such as fluidity, air content and the strength of hardened concrete etc, and can reduce bleeding effectively. Therefore it is thought that bleeding reduction agent can be applied to construction field effectively.

The Reduction Properties of Nitrate in Water with Palladium and Indium on Aluminum Pillared Montmorillonite Catalyst (팔라디움과 인디움을 담지한 Al 층간가교 몬모릴로나이트 촉매의 수중 질산성질소 환원 특성)

  • Jeong, Sangjo
    • Journal of Korean Society on Water Environment
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    • v.34 no.6
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    • pp.621-631
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    • 2018
  • In this study, catalyst was made through incipient wetness method using palladium (Pd) as noble metal, indium (In) as secondary metal, and montmorillonite (MK10) and Al pillared montmorillonite (Al-MK10) as supporters. The nitrate reduction rate of the catalysts was measured by batch experiments where H2 gas was used as reducing agent and formic acid as pH controller. Transmission electron microscopy (TEM) equipped with energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) were all used to determine the elemental distribution of Pd, In, Al, and Si on catalysts. It was observed that Al pillaring increased the Al/Si elemental composition ratio and point of zero charge of MK10, but decreased its BET specific surface area and pore volume. The nitrate reduction rate of Al-MK10 Pd/In was 2.0 ~ 2.5 times higher than that of MK10 Pd/In using artificial groundwater (GW) in ambient temperature and pressure. Nitrate reduction rates in GW were 1.2 ~ 1.7 times lower than those in distilled deionized water (DDW). Nitrate reduction rates in acidic conditions were higher than those in neutral condition in both GW and DDW. The amount of produced NH3-N over degraded NO3- at acid conditions was lower than that of neutral condition. Even though the leaching of Pd after reaction was measured in DDW it was not detected when both Al-MK10 Pd/In and MK10 Pd/In were used in GW. The modification of montmorillonite as a supporter significantly increased the reductive catalytic activities of nitrates. However, the ratio of producing ammonia by-products to degraded nitrates in ambient temperature and pressure was similar.

Relationship between rotational disc displacement of the temporomandibular joint and the dentoskeletal morphology

  • Park, So-Hyun;Han, Won-Jeong;Chung, Dong-Hwa;An, Jung-Sub;Ahn, Sug-Joon
    • The korean journal of orthodontics
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    • v.51 no.2
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    • pp.105-114
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    • 2021
  • Objective: The purpose of this study was to evaluate the relationship between rotational disk displacement (DD) of the temporomandibular joint (TMJ) and the dentoskeletal morphology. Methods: Women aged > 17 years were included in this study. Each subject had a primary complaint of malocclusion and underwent routine cephalometric examinations. They were divided into five groups according to the findings on sagittal and coronal magnetic resonance images of their TMJs: bilateral normal disk position, bilateral anterior DD with reduction (ADDR), bilateral rotational DD with reduction (RDDR), bilateral anterior DD without reduction (ADDNR), and bilateral rotational DD without reduction (RDDNR). Twenty-three cephalometric variables were analyzed, and the Kruskal-Wallis test was used to evaluate differences in the dentoskeletal morphology among the five groups. Results: Patients with TMJ DD exhibited a hyperdivergent pattern with a retrognathic mandible, unlike those with a normal disk position. These specific skeletal characteristics were more severe in patients exhibiting DD without reduction than in those with reduction, regardless of the presence of rotational DD. Rotational DD significantly influenced horizontal and vertical skeletal patterns only in the stage of DD with reduction, and the mandible exhibited a more backward position and rotation in patients with RDDR than in those with ADDR. However, there were no significant dentoskeletal differences between ADDNR and RDDNR. Conclusions: The results of this study suggest that rotational DD of TMJ plays an important role in the dentoskeletal morphology, particularly in patients showing DD with reduction.

Evidence-based use of cold for plantar fasciitis

  • Laymon, Michael S.;Petrofsky, Jerrold S.;Alshammari, Faris;Fisher, Stacy
    • Physical Therapy Rehabilitation Science
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    • v.2 no.2
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    • pp.75-80
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    • 2013
  • Objective: The purpose of this study was to examine the effect of cold applied the night before or in the morning on pain and symptoms of plantar fasciitis. Design: Experimental study. Methods: Thirty subjects with plantar fasciitis were recruited for this study. Subjects with plantar fasciitis either had no intervention, cold applied (20 minutes) at night before bed, or 20 minutes in the morning upon wakening. Plantar fascia tenderness and pain were evaluated. There were ten subjects in each group. Measures included visual analog scale, plantar facial thickness via high resolution ultrasound, algometer measure, and range of motion of the ankle and foot. There were 3 groups of 10 subjects, control (no intervention), cold the night before bed, and cold in the morning before rising. Results: The greatest relief of symptoms was cold used at bedtime the night before the measurements. Cold used in the morning was not as effective as cold used in the evening before bed. Cold use reduced the thickness of the plantar fascia and irritation. There was a 13% reduction in plantar fascia thickness with cold the night before (p<0.05), a 44% reduction in pain and an 86 % increase in the force that could be applied to the bottom of the foot without pain (p<0.05). Conclusions: Cold applied for 20 minutes prior bedtime is effective for reduced symptomology caused by plantar fascia inflammation.

Anthelminthic Effect of Oxantel Pamoate against Trichocephalus trichiurus Infection (Oxantel pamoate의 편충(鞭虫)에 대한 구충효과(驅虫效果))

  • Lim, J.K.
    • The Korean Journal of Pharmacology
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    • v.10 no.2
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    • pp.25-29
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    • 1974
  • The present clinical trial was performed to evaluate the anthelminthic effect and tolerance of Oxantel pamoate, a new antiwhipworm agent, in the treatment of T. trichiurus infection. Oxantel pamoate oral suspension was administered as a sing1e dose of 10 mg per kg. body weight to a total of 46 T. trichiurus infected cases selected out of 64 positives, by examining 89 fecal specimens collected from the soldiers and in-patients of xx Armed Forces General Hospital. For the evaluation, the negative conversion rate (cure rate) and the egg reduction rate were assessed 22 days after the treatment. The result obtained were as follows: 1. The prevalence rate of T. trichiurus infection in this study was 71.9%, while the mean E.P.G. of 46 treated cases was 126. 2. The egg negative conversion rate was 91.3%, and 98.4% of egg reduction rate was obtained. 3. From the observation of 107 worms expelled during 3 consecutive days after the treatment, it was known that sex ratio of male and female was about 1 : 2 and that average worm burden per capita was 2.3. 4. In all treated cases, the medication was readily accepted and well tolerated. On the hemograms, urinalysis and liver function tests, no significant differences were noted before and after the drug administration. There was also no detectable objective and subjective side effect.

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Removal of S $O_{2}$ and NO by Dry Sorbent(II) - Efficiency of Cu-Ce and Cu-7Al - (건식법에 의한 이산화황과 산화질소의 제거(II) - Cu-Ce 및 Cu-7Al의 효율 -)

  • 신창섭
    • Journal of Korean Society for Atmospheric Environment
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    • v.9 no.4
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    • pp.288-294
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    • 1993
  • Flue gas control systems for small-scale combustors must be designed to provide highly effective removal of three criteria pollutants (S $O_{2}$, N $O_{x}$ and particulate matter), and must be safe, reliable and small. These requirements make dry, regenerative clean-up process particularly attractive and this paper describes a new concept for integrated pollutant control : a filter comprised of layered, gas permeable membranes that act as an S $O_{2}$ sorbant, a N $O_{x}$ reduction catalyst and a particulate filter. A mixed metal oxide sorbent, Cu-Ce was used as a sorbent/catalyst and the activity was compared with Cu-7Al. The S $O_{2}$ removal eficiency of Cu-Ce was increased with temperature increase up to 500$^{\circ}$C and the catalytic activity for NO was higher than that of Cu-7Al. By the sulfation of Cu-Ce, the reduction activity was increased at the temperature higher than 350$^{\circ}$C. The regeneration of Cu-Ce was very fast and some amount of elemental sulfar was found.

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A Study on a Combined DeNOx Process of Plasma Oxidation and $NH_3$ SCR for Diesel Engine (플라즈마 산화와 암모니아 SCR 복합탈질공정의 엔진적용 연구)

  • Song, Young-Hoon;Lee, Jae-Ok;Cha, Min-Suk;Kim, Seock-Joon;Ryu, Jeong-In
    • Journal of the Korean Society of Combustion
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    • v.12 no.4
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    • pp.39-46
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    • 2007
  • The technique of $NH_3$ SCR (selective catalytic reduction) assisted by plasma oxidation has been applied to a 2,000 cc diesel engine. The present combined $deNO_x$ process consists of two steps. The first step is that about 50% of emitted NO from the engine is oxidized to $NO_2$ in a plasma oxidation process. The second step is that NO and $NO_2$ are simultaneously reduced to $N_2$ in the $NH_3$ SCR process. The engine test results showed that the $deNO_x$ rates of the present combined process are higher than those of conventional SCR process by 20%. Such a high performance of the combined process is noticeable especially, when the exhaust temperature are relatively low, i.e., $170-220^{\circ}C$. To provide a feasibility of the present technique the effects of operating conditions, such as an electrical input energy, an exhaust gas temperature, an initial NO concentration, and the amount of hydrocarbon addition, were discussed.

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