• Title/Summary/Keyword: Nitrous oxide concentration

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Modeling Study on Dispersion and Scavenging of Traffic Pollutants at the Location Near a Busy Road

  • Ma, Chang-Jin
    • Asian Journal of Atmospheric Environment
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    • v.9 no.4
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    • pp.272-279
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    • 2015
  • The information about the dispersion and scavenging of traffic-related pollutants at the locations near busy expressways is very helpful to highway planners for developing better plans to reduce exposures to air pollution for people living as well as children attending schools and child care centers near roadways. The objective of the current study was to give information in the dispersion and scavenging of vehicle-derived pollutants at the region near a busy urban expressway by a combination of two different model calculations. The modified Gaussian dispersion model and the Lagrange type below-cloud scavenging model were applied to evaluate $NO_x$ dispersion and DEP (Diesel exhaust particles) wet removal, respectively. The highest $NO_x$ was marked 53.17 ppb within 20-30 meters from the target urban expressway during the heaviest traffic hours (08:00AM-09:00AM) and it was 2.8 times higher than that of really measured at a nearby ambient measuring station. The calculated DEP concentration in size-resolved raindrops showed a continuous decreasing with increasing raindrop size. Especially, a noticeable decrease was found between 0.2 mm and 1.0 mm raindrop diameter.

A Survey of the Outpatient General Anesthesia and Dental Treatment in Chungnam Dental Clinic for the Disabled (충남장애인구강진료센터에서 시행된 외래전신마취와 치과치료에 대한 조사연구)

  • You, Yon-Sook;Kim, Jong-Su;Kim, Seung-Oh
    • Journal of The Korean Dental Society of Anesthesiology
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    • v.11 no.2
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    • pp.133-140
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    • 2011
  • Background: Dental treatment under outpatient general anesthesia is an option for disabled person, children and dentally disabled person who have the difficulty of cooperating voluntary with dental care. The aim of this study was to access the patients who had dental management under general anesthesia at Chungnam dental clinic for the disabled. Methods: This survey is consisted of 114 severely disabled and dentally disabled person who undergone dental treatment under general anesthesia from January to June 2011. Data were collected by individual dental and anesthesia records. Results: Of the 114 patients studies, the 45 patients was the dentally disabled and the 69 patients was the severely disabled. Rate of dental treatment among male patients was higher than among female patients. The dentally disabled was an similar age distribution. In the severly disabled, above 13-year-old was higher than below 12-year-old. The most popular induction method of general anesthesia was sevoflurane inhalation after induced sedative effect of nitrous oxide inhalation. The severly disabled who had definitely negative behavior was applied inhalation of high concentration sevoflurane. Conclusions: Chungnam Dental clinic for the disabled provide dental management for the disabled and the dentally disabled.

Assessing the Role of Citric Acid in Denitrification of Nitrate in Slow-releasing Carbon Source Tablet (완효성 탄소원 정제 내 citric acid의 생물학적 탈질소화 영향)

  • Han, Kyungjin;Yeum, Yuhoon;Kim, Young;Kwon, Sooyoul
    • Journal of Soil and Groundwater Environment
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    • v.27 no.3
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    • pp.41-49
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    • 2022
  • This study utilized citric acid as a floating agent in biological denitrification process and assessed its role under different carbon supplying conditions. Several microcosm tests including citric acid active (CAA), precipitating tablet release active (PTRA) and floating tablet release active (FTRA) were conducted to evaluate nitrate denitrification efficacy. In CAA reactors, nitrate removal was accompanied by the formation of denitrification by-products such as nitrite and nitrous oxide, with the extent of nitrate removal being proportional to citric acid concentration. These results suggest that citric acid induced heterotrophic biological denitrification. PTRA reactor that incorporated CAA and the same electron donor showed a similar denitrification efficiency to CAA reactor. FTRA reactor, which contained the same amount of fumarate as PTRA, enhanced denitrification by 7% as compared to the PTRA reactor. The overall results of this work indicate that surplus citric acid can be efficiently utilized in heterotrophic denitrification.

Properties of the oxynitride films prepared by reoxidation of thermal oxide in $N_2O$ ($N_2O$ 가스에서 열산화막의 재산화에 의해 형성된 oxynitride막의 특성)

  • Bae, Sung-Sig;Lee, Cheol-In;Choi, Hyun-Sik;Seo, Yong-Jin;Kim, Tae-Hyung;Kim, Chang-Il;Chang, Eui-Goo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1993.05a
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    • pp.39-43
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    • 1993
  • Electricial characteristics of gate dielectrics prepared by reoxidation of thermal $SiO_2$ in nitrous oxide gas have been investigated. 10 and 19nm-thick oxides were reoxidized at temperatures of $900-1000^{\circ}C$ for 10-60 min in $N_2O$ ambient. As reoxidation proceeds, it is shown that nitrogen concentration at $Si/SiO_2$ interface increases gradually through the AES analysis. Nitrogen pile-up at $Si/SiO_2$ interface acts as a oxidant diffusion barrier that reduces the oxidation rate significantly. And it not only strengthen oxynitride structure at the interface but improve the gate dielectric qualities. Reliabilities of oxynitride films are conformed by the breakdown distributions and constant current stress technique. Therefore, the oxynitride films made by this process show a good promise for future ULSI applications.

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Greenhouse gases emission from aerobic methanotrophic denitrification (AeOM-D) in sequencing batch reactor

  • Lee, Kwanhyoung;Choi, Oh Kyung;Lee, Jae Woo
    • Membrane and Water Treatment
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    • v.8 no.2
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    • pp.171-184
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    • 2017
  • This study presents the effect of hydraulic retention time (HRT) on the characteristics of emission of three major greenhouse gases (GHGs) including $CH_4$, $CO_2$ and $N_2O$ during operation of a sequencing batch reactor for aerobic oxidation of methane with denitrification (AeOM-D SBR). Dissolved $N_2O$ concentration increased, leveled-off and slightly decreased as the HRT increased from 0.25 to 1d. Concentration of the dissolved $N_2O$ was higher at the shorter HRT, which was highly associated with the lowered C/N ratio. A longer HRT resulted in a higher C/N ratio with a sufficient carbon source produced by methanotrophs via methane oxidation, which provided a favorable condition for reducing $N_2O$ formation. With a less formation of the dissolved $N_2O$, $N_2O$ emission rate was lower at a longer HRT condition due to the lower C/N ratio. Opposite to the $N_2O$ emission, emission rates of $CH_4$ and $CO_2$ were higher at a longer HRT. Longer HRT resulted in the greater total GHGs emission as $CO_2$ equivalent which was doubled when the HRT increased from 0.5d to 1.0 d. Contribution of $CH_4$ onto the total GHGs emission was most dominant accounting for 98 - 99% compared to that of $N_2O$ (< 2%).

Emission Characteristics of Greenhouse Gases (CH4, N2O) in Mechanically Ventilated Swine Farm during Winter Season (겨울철 강제환기식 돈사 내 온실가스 (CH4, N2O) 배출 특성 연구)

  • Park, Junyong;Jung, Minwoong;Jo, Gwanggon;Jang, Yu-Na
    • Journal of The Korean Society of Agricultural Engineers
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    • v.63 no.4
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    • pp.33-41
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    • 2021
  • The emission characteristics and emission factors were determined by measuring the concentration of methane (CH4) and nitrous oxide (N2O), the amount of ventilation, etc. in the two fattening rooms which have the same environment in winter. As a result of monitoring, the average concentration of CH4 and N2O was 20.7-26.7 ppm and 1.4-1.6 ppm. The average temperature inside the room was measured at 20.0-21.4℃, and the average ventilation was 1345.4-1567.3 m3/h. The daily emission of CH4 for the first 30 days showed a constant emission of 3.6-8.2 g/d/m2/pig, but thereafter, the emission increased rapidly. The daily emission of N2O was 0.7-1.3 g/d/m2/pig, showing stable emission during the test period, and relatively insignificant emission compared to the emission of CH4. After repeated test, it was confirmed that there was no significant difference between the two rooms. As a result, the CH4 6. 21 g/d/m2/pig and N2O 1.02 g/d/m2/pig average emission for each room was derived.

The Effect of Lidocaine Dose and Pretreated Diazepam on Cardiovascular System and Plasma Concentration of Lidocaine in Dogs Ansthetized with Halothane-Nitrous Oxide (Diazepam 전투여와 Lidocaine 투여용량이 혈중농도 및 심혈역학적 변화에 미치는 영향)

  • Lee, Kyeong-Sook;Kim, Sae-Yeon;Park, Dae-Pal;Kim, Jin-Mo;Chung, Chung-Gil
    • Journal of Yeungnam Medical Science
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    • v.10 no.2
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    • pp.451-474
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    • 1993
  • Lidocaline if frequently administered as a component of an anesthetic : for local or regional nerve blocks, to mitigate the autonomic response to laryngoscopy and tracheal intubation, to suppress the cough reflex, and for antiarrythmic therapy. Diazepam dectease the potential central nervous system (CNS) toxicity of local anesthetic agents but may modify the sitmulant action of lidocaine in addition to their own cardiovascular depressant. The potential cardiovascular toxicity of local anesthetics may be enhanced by the concomitant administration of diazepam. This study was designed to investigate the effects of lidocaine dose and pretreated diazepam to cardiovascular system and plasma concentration of lidocaine. Lidocaine in 100 mcg/kg/min, 200 mcg/kg/min, and 300 mcg/kg/min was given by sequential infusion to dogs anesthetized with halothane-nitrous oxide (Group I). And in group II, after diazepam pretreatment, lidocaine was infused by same way when lidocaine was administered in 100 mcg/kg/min, the low plasma levels ($3.97{\pm}0.22-4.48{\pm}0.36$ mcg/ml) caused a little reduction in cardiovascular hemodynamics. As administered in 200 mcg/kg/min, 300 mcg/kg/min, the higher plasma levels ($7.50{\pm}0.66-11.83{\pm}0.59$ mcg/ml) reduced mean arterial pressure (MAP), cardiac index (CI), stroke index (SI), left ventricular stroke work index (LVSWI), and right ventricular stroke work index (PVSWI) and increased pulmonary artery wedge pressure (PAWP), central venous pressure (CVP), systemic vascular resistance index (SVRI), but was associated with little changes of heart rate (HR), mean pulmonary artery pressure (MPAP), and pulmonary vascular resistance index (PVRI). When lidocaine with pretreated diazepam was administered in 100 mcg/kg/min, the low plasma level, the lower level than when only lidocaine administered, reduced MAP, but was not changed other cardiovascular hemodynamics. While lidocaine was infused in 200 mcg/kg/min, 300 mcg/kg/min in dogs pretreated diazepam, the higher plasma level ($7.64{\pm}0.79-13.79{\pm}0.82$ mcg/ml) was maintained and was associated with reduced CI, SI, LVSWI and incresed PAWP, CVP, SVRI but was a little changes of HR, MPAP, PVRI. After $CaCl_2$ administeration, CI, SI, SVRI, LVSWI was recovered but PAWP, CVP was rather increased than recovered. The foregoing results demonstrate that pretreated diazepam imposes no additional burden on cardiovascular system when a infusion of large dose of lidocaine is given to dogs anesthetized with halothanenitrous oxide. But caution may be advised if the addition of lidocaine is indicated in subjects who have impared autonomic nervous system and who are in hypercarbic, hypoxic, or acidotic states.

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Effects of Chelidonii Herbal-acupuncture solution Anti-inflammatory in RAW 264.7 macrophages (백굴채약침액(白屈菜藥針液)이 LPS로 유도(誘導)된 RAW 264.7 대식세포(大食細胞)에서의 항염증효과(抗炎症效果))

  • Park, Dong-Cheon;Park, Ji-Hyeon;Lee, U-Kyung;Leek, Jin-Kyu;Seo, Il-Bok;Kim, Ho-Hyun;Kim, Jeong-Seon;Kim, Ee-Hwa
    • Korean Journal of Acupuncture
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    • v.21 no.2
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    • pp.125-137
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    • 2004
  • Objectives : Recently, Herbal-acupuncture therapeutics has been used for the treatment of inflammatory diseases such as rheumatoid arthritis. Especially, we have been interested in chemical mediators concerned with inflammation such as prostaglandin, cytokine, nitrous oxide. The purpose of this study is investigated that the effect of Chelidonii Herbal-acupuncture solution in lipopolysaccharide-stimulated RAW 264.7 macrophages, performed several expeimental items : those are prostaglandin $E_2$, nitric oxide and cyclooxygenase-2. Methods : The cytotoxicity of Chelidonii Herbal-acupuncture solution in RAW 264.7 macrophages were measured by MTT-based cytotoxicity assay. In order to observe cyclooxygenase-2 mRNA expression in lipopolysaccharide-stimulated RAW 264.7 macrophages, RT-PCR was used. Prostaglandin $E_2$ formation and nitric oxide production was measured by competitive enzyme immunoassay and Griess assay. Results : 1.The MTT assay demonstrated that cytotoxic effect of Chelidonii Herbal-acupuncture solution in RAW 264.7 macrophages were not appeared before concentration of 1mg/ml. 2.Chelidonii Herbal-acupuncture solution inhibited cyclooxygenase-2 mRNA expression in lipopolysaccharide-stimulated RAW 264.7 macrophages. 3. Chelidonii Herbal-acupuncture solution inhibited nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 macrophages. 4. Chelidonii Herbal-acupuncture solution inhibited prostaglandin $E_2$ formation in lipopolysaccharide-stimulated RAW 264.7 macrophages. Conclusions : On the basis of these results, It was shown that Chelidonii Herbal-acupuncture solution is significantly able to inhibit the production of $PGE_2$ and NO, as well as COX-2 mRNA expression. Our results may provide new mechanism by which Chelidonii Herbal-acupuncture solution accounts for its beneficial effect on accelerating wound healing and anti-inflammation.

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International Rule for Environment and International Trade (국제환경규범(國際環境規範)과 무역연계(貿易連繫))

  • Shin, Han-Dong
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.12
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    • pp.587-613
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    • 1999
  • Environmental problems such as global climate change, depletion, ocean and air pollution, and resource degradation-compounded by an expanding world population-respect no border and threaten the health, prosperity and jobs of all mankind. Our efforts to promote democracy, free trade, and stability in the world will fall short unless people have a livable environment. We have an enormous stake in the management of the world's resources. By increasing demand for timber, natural gas, coal and consumer's goods have destroyed the grounds for living. Greenhouse gas emissions anywhere in the world have threatened coastal communities, and then changed the Earth's climate system. The burning of coal, oil, and other fossil fuels is increasing substantially the concentration of heat-trapping gasses such as carbon dioxide, methane, and nitrous oxide in our air. The earth's temperature and sea levels are rising as a result. Since 1972 there has been a marked growth in the number and scope of environmental treaties. In particular, after the 1992 Rio Conference, international legal instruments became more concentrated on addressing environment within the context of sustainable development and incorporated a number of new concepts and innovative approaches. A preliminary analysis of recent conventions and in particular those associated with the Rio Conference indicates various ideas, concepts and principles which have come to the fore including sustainable development, equity, common concern of humankind, common but differentiated responsibilities and global partnership. However, international trade also has an environmental impact which must be minimized or countered. Positive measures are to be preferred to achieve environmental goals, but where trade provisions are necessary, they should be appropriately used within environmental conventions to facilitate the reduction and limitation of the negative impacts of trade and to enhance the complementarity of the multilateral trade regime with the imperatives of environmental protection, in the interests of environmental protection and sustainable development generally. The international community has to recognize and endorse this need to achieve complementarity between trade and environment issues.

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The effect of feeding high fat diet to beef cattle on manure composition and gaseous emission from a feedlot pen surface

  • Gautam, Dhan Prasad;Rahman, Shafiqur;Borhan, Md Saidul;Engel, Chanda
    • Journal of Animal Science and Technology
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    • v.58 no.6
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    • pp.22.1-22.15
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    • 2016
  • Background: Dietary manipulation is a common practice to mitigate gaseous emission from livestock production facilities, and the variation of fat level in the diet has shown great influence on ruminal volatile fatty acids (VFA) and enteric methane generation. The changes in dietary fat levels influence rumen chemistry that could modify manure nutrient composition along with odor and gaseous emissions from manure management facilities. Methods: A field experiment was carried out on beef cattle feedlots to investigate the effect of four levels of dietary fat concentrations (3 to 5.5 %) on the manure composition and gaseous emissions (methane-$CH_4$, nitrous oxide-$N_2O$, carbon dioxide-$CO_2$ and hydrogen sulfide-$H_2S$) from the feedlot pen surface. The experiment was carried out over a 5-month period from June to October during North Dakota's summer-fall climatic condition. Air and manure sampling was conducted five times at a 20-30 day intervals. Results: Overall, this research indicated that fat levels in diet have no or little effect on the nutrient composition of manure and gaseous emission from the pens with cattle fed with different diet. Though significant variation of gaseous emission and manure composition were observed between different sampling periods, no effect of high fat diet was observed on manure composition and gaseous emission. Conclusions: It can be concluded that addition of fat to animal diet may not have any impact on gaseous emission and manure compositions.