• Title/Summary/Keyword: Side reactions

Search Result 331, Processing Time 0.022 seconds

Formation of N2O in NH3-SCR DeNOxing Reaction with V2O5/TiO2-Based Catalysts for Fossil Fuels-Fired Power Stations (화력발전소용 V2O5/TiO2계 촉매상에서 NH3-SCR 탈질반응으로부터의 N2O 생성)

  • Kim, Moon Hyeon
    • Korean Chemical Engineering Research
    • /
    • v.51 no.2
    • /
    • pp.163-170
    • /
    • 2013
  • Selective catalytic reduction of $NO_x$ by $NH_3$ ($NH_3$-SCR) over $V_2O_5/TiO_2$-based catalysts is recently reported to be an anthropogenic emitter of $N_2O$ that is a global warming gas with a global warming potential of 310. Therefore, this review will get a touch on significance of some parameters regarding $N_2O$ formation in the $deNO_xing$ reaction for fossil fuels-fired power plants applications. The $N_2O$ production in $NH_3$-SCR reaction with such catalysts occurs via side reactions between $NO_x$ and $NH_3$ in addition to $NH_3$ oxidation, and the extent of these undesired reactions depends strongly on the loadings of $V_2O_5$ as a primary active component and the promoter as a secondary one ($WO_3$ and $MoO_3$) in the SCR catalysts, the feed and operating variables such as reaction temperature, $NO_2/NO_x$ ratio, oxygen concentration, gas hourly space velocity, water content and thermal excursion, and the physical and chemical histories of the catalysts on site. Although all these parameters are associated with the $N_2O$ formation in $deNO_xing$ reaction, details of some of them have been discussed and a better way of suppressing the $N_2O$ production in commercial SCR plants has been proposed.

A Study on Wearing Test of Protective Clothing against a Toxic Substance (유해물질 차단을 위한 방호복의 착용실험에 관한 연구)

  • Chung, Myung-Hee;Park, Soon-Ja;Shin, Jung-Sook;Koshiba, Tomoko;Tamura, Teruko
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.30 no.11 s.158
    • /
    • pp.1626-1635
    • /
    • 2006
  • The purpose of this study was to search for comfortable protective clothing for waste incinerator workers. The experimental protective clothing came in two types: one whose outer side made use of polypropylene film, and the inner side, a non-woven rayon fabric processed with charcoal with a 10% density (CF): and one whose outer side made use of polyolefine and polyamide films, and the inner side, a non-woven polypropylene fabric (NNCF). Experiments were conducted on five healthy adult women whose average age was 21. These experiments were conducted at a climate chamber, in which the temperature and relative humidity were set below $28{\pm}1^{\circ}C\;and\;50{\pm}10%$, respectively. Measured were the rectal temperature, the skin temperature, the sweating rate, the weight loss, the heart rate, the blood pressure, the temperature, and the relative humidity of a microclimate and subjective sensation. These were measured within a period of 60 min, consisting of a 20-min stable period, a 20-min exercise period (walking exercise for 2 miles/hr on a treadmill), and a 20-min recovery period. Through this experiment, the differences between the human body's physiological reactions to CF and NNCF clothing, and the human body's comfort levels when wearing these, were determined.

The Experimental Study of the End-to-side Microarterial Anastomosis with the Longitudinal Slit and the Triangular Flap (고전적 및 삼각조각 기법을 이용한 단-측면 미세동맥 접합술의 실험적 연구)

  • Lee, Jun-Mo;Lee, Gang-Wook;Lee, Dong-Geun
    • Archives of Reconstructive Microsurgery
    • /
    • v.1 no.1
    • /
    • pp.51-55
    • /
    • 1992
  • Problems of composite tissue transfer commonly arise when a single indispensable recipient vessel receives the graft vssel, and the graft vessel must be sutured in end-to-side fashion so as not todisturb the vascularity of the recipient vessel. The triangular flap in the recipient vessel wall gives an intact endothelial surface when the flow of blood stream is presented and may reduce the chance of anastomosis. We selected mature Wistar rats weighing over 450 grams to compare the conventional longitudinal slit from the triangular flap in the recipient carotid artery over bloood pressure and blood flow when the donor carotid artery was anastomosed in end-to-side fashion. In 30 minutes after anastomosis, maximum blood pressure measured in the donor carotid arterial side when the recipient arterial wall was fasioned with the longitudinal slit was recorded 114 mmHg and with the triangular flap 100mmHg. Minimum blood pressure with the longitudinal slit was 98mmHg and with the triangular flap 88mmHg. The amount of blood collected for 30 seconds in the conventional longitudinal slit was 1.18mg and in the triangular flap 0.78mg. Histology study in 30 minutes, the conventional longitudinal slit demonstrated the more hemorrhagic features around the suture material compared to that of the triangular. flap and, in the 7th day, the conventional longitudinal slit demonstrated the more prominent granulomatous reactions and vascular proliferations around the suture material compared to that of the triangular flap.

  • PDF

Preparation of Smectic Layered Polymer Networks Using Side Chain Liquid Crystalline Polymers Having Latent Reactive Monomeric Units

  • Oh, Young-Taek;Kim, Woo-Jin;Seo, Sang-Hyuk;Chang, Ji-Young
    • Macromolecular Research
    • /
    • v.17 no.2
    • /
    • pp.84-90
    • /
    • 2009
  • We prepared side-chain liquid crystalline polymers comprising two monomeric units, one having a mesogenic side group that could form a smectic mesophase and the other having a phenolic group attached to the polymer backbone via a thermally reversible urethane bond. The urethane linkage between the isocyanate and phenol groups was stable at room temperature, but it cleaved to generate an isocyanate group when the temperature was increased. When annealed, the copolymers in their smectic mesophases became insoluble in common organic solvents, suggesting the formation of network structures. XRD analysis showed that the annealed polymers maintained their smectic LC structures. The crosslinking process probably proceeded via the reaction of the dissociated isocyanate groups. Some of the isocyanate groups would have first reacted with moisture in the atmosphere to yield amino groups, which underwent further reaction with other isocyanate groups, resulting in the formation of urea bonds. We presume that only polymer chains in the same layer were crosslinked by the reaction of the isocyanate groups, resulting in the formation of a layered polymer network structure. Reactions between the layers did not occur because of the wide layer spacing.

Review about using Herbal medicine on steroid tapering and steroid overuse in Skin disease (피부과 영역에서 steroid 테이퍼링 및 남용 완화를 위한 한약 사용에 대한 고찰)

  • Han, Chang-Yi;Kim, Jun-Dong;Kang, Dong-Won;Kim, Kyu-Seok;Kim, Yoon-Bum
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
    • /
    • v.33 no.3
    • /
    • pp.115-124
    • /
    • 2020
  • Objectives : The purpose of this study is to investigate the effect and side effects of steroids on dermatitis and skin barrier through lipid metabolism. And to propose using Herbal medicine to suppress Steroid rebound and prevent side effects. Methods : We reviewed recent studies about the relationship between dermatitis, skin lipid, steroid, and herbal medicine through Google scholar. Results : In various inflammatory skin diseases, the corticosteroid is selected as the primary drug due to its strong anti-inflammatory and immunosuppressive effect. However, long-term use of steroids has a variety of side effects, especially lipid metabolism disruption, which aggravates skin barrier damage underlying various skin diseases and is more susceptible to inflammatory reactions. Conclusions : Herbal medicine is used as a comprehensive approach, and it can be used to reduce the frequency of steroid exposure by protecting against barrier damage by controlling anti-inflammatory, antioxidant, and systemic/sebaceous lipid metabolism and stratum corneum protein differentiation.

Error-compensating Techniques in 3-Point Weighing Method to Measure Unbalance Properties (3점 방식 불평형량 측정법에서의 오차보상 기법)

  • Lee, Sun-Pyo
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.23 no.11 s.188
    • /
    • pp.42-49
    • /
    • 2006
  • In this paper error-compensating techniques in three-point weighing method to precisely measure unbalance properties such as center of gravity and unbalance moment. In the conventional static methods, 1) fixture-errors, 2) effects of the contact between the fixture and the load scales, and 3) side effect due to the lateral frictional forces acting on the contact points between the fixture and the load scales are the major factors that lead to measurement errors. The proposed error-compensating method perfectly eliminates both the fixture-error and the contact-error simultaneously by manipulating the three measured reaction forces at three different angular locations. Also the friction-error is calibrated by comparing the sum of three reactions with the actual mass of the specimen. A set of measurement is performed using the same measuring system as Lee's, and a comparison of the results from the convectional, Lee's, and the proposed method is provided. The results show that the proposed method effectively compensates the errors listed above.

The Analysis of 278 Cases Who were Medicated with Cheonga-won (청아원을 사용한 환자 278례에 대한 증례 분석)

  • Kang, Jae-Hui;Lee, Hyun;Choi, Joo-Young;Yoon, Kwang-Sik
    • Journal of Acupuncture Research
    • /
    • v.28 no.1
    • /
    • pp.93-100
    • /
    • 2011
  • Objectives : The purpose of this study is to observe the general distribution that was medicated with Cheonga-won. Methods : The 278 patients who were medicated with Cheonga-won more than two weeks in Cheonan oriental hospital, Daejeon university from December 2007 to December 2010 were observed. The other general oriental therapys were also carried out according to individual condition. The 278 patients were analyzed according to the distribution of sex, age, the period of medication, symptoms, the change of VAS score and T-score, side effects and abnormal reactions. Results : 1. Cheonga-won was mostly used for Shin-huh, which induces lower back pain, knee pain, vertigo, dysuria, tinnitus. 2. More patients in their fifties, sixties and seventies were prescribed with the medication than those in their thirties and forties. 3. After medication with Cheonga-won, there are tendency in reduce chronic pain. 4. After medication with Cheonga-won, there are tendency in increase BMD(bone mineral density). 5. There are no side effects and abnormal reaction cases that related with Cheonga-won. Conclusions : Cheonga-won was used in Shin-huh symptoms, and may be effective in reduce chronic pain, improve Shin-huh symptoms and increase BMD.

Characterization of Potassium Based Dry CO2 Sorbents Developed for the Reduction of Side Reactions (부반응 저감 조성 K계 건식 CO2 흡수제 특성평가)

  • Jang, Young-shin;Kim, Ui-sik;Yoon, Yang-no;Baek, Jeom-In
    • KEPCO Journal on Electric Power and Energy
    • /
    • v.5 no.4
    • /
    • pp.337-341
    • /
    • 2019
  • In this study, the effects of two materials, active alumina and CaO based inorganic binder, which cause the side reaction on the K2CO3-based solid CO2 sorbents was investigated. K2CO3-based solid sorbents called KAM series was prepared by spray drying method and then measured its physical properties and CO2 sorption capacity. Among the KAM series sorbents, KAM(0.5) maintained high CO2 sorption capacity of 7.6 wt% after 3 cycle of sorption/regeneration reaction and showed very low attrition loss as low as 3.1 % which was measured by ASTM D5757-95.

Coupling effect of Cu(ENIG)/Sn-Ag-(Cu)/Cu(ENIG) sandwich solder joint (Cu(ENIG)/Sn-Ag-(Cu)/Cu(ENIG) sandwich solder 접합부의 Coupling 효과)

  • Yun Jeong-Won;Jeong Seung-Bu
    • Proceedings of the KWS Conference
    • /
    • 2006.05a
    • /
    • pp.33-35
    • /
    • 2006
  • The interactions between Cu/Sn-Ag-(Cu) and Sn-Ag-(Cu)/Ni interfacial reactions were studied during isothermal aging at $150^{\circ}C$ for up to 1000h using Cu(ENIG)/Sn-3.5Ag-(0.7Cu)/Cu(ENIG) sandwich solder joints. A typical scallop-type Cu-Sn intermetallic compound (IMC) layer formed at the upper Sn-Ag/Cu interface after reflowing, whereas a $(Cu,Ni)_6Sn_5$ IMC layer was observed at the Sn-Ag/ENIG interface. The Cu in the $(Cu,Ni)_6Sn_5$ IMC layer formed on the Ni side was sourced from the dissolution of the opposite Cu metal pad or Cu-Sn IMC layer. When the dissolved Cu arrived at the interface of the Ni pad, the $(Cu,Ni)_6Sn_5$ IMC layer formed on the Ni interface, preventing the Ni pad from reacting with the solder. Although a long isothermal aging treatment was performed at $150^{\circ}C$, no Ni was detected in the Cu-Sn IMC layer formed on the Cu side. Compared to the single Sn-Ag/ENIG solder joint, the formation of the $(Cu,Ni)_6Sn_5$ IMC layer of the Cu/sn-Ag/ENIG sandwich joint effectively retarded the Ni consumption from the electroless Ni-P layer.

  • PDF

A Study of Reports about Dizziness Reaction - Focus on the China Academic Journal - (명현(瞑眩) 반응에 대한 보고 연구 - China Academic Journal을 중심으로 -)

  • Yoon, Cheol-Ho
    • The Journal of Korean Medicine
    • /
    • v.30 no.5
    • /
    • pp.1-15
    • /
    • 2009
  • Objectives: I carried out this study for research on dizziness (瞑眩) reaction. Methods: I found 14 papers about dizziness reaction from 1994 to 2009 in China Academic Journal (CAJ) website, and synthesized these reports. Results: Dizziness reaction, presupposing that the diagnosis and treatments are correct, is a peculiar reaction which occurs with severe and various symptoms temporarily diverging from regular course. As dizziness reaction disappears, the symptoms of the disease are improved. Though it mostly occurs rapidly and disappears in a short time, it can occur after a long treatment or occur gradually in chronic diseases. As a general rule, the faster dizziness reaction occurs, the more severe the reaction. The faster dizziness reaction disappears, the quicker the recovery from illness. Upon catching a disease, healthy qi(正氣) and the pathogen (邪氣) fight each other. Just at that moment, if the medicine or acupuncture treatment hits the mark of the pathogen (邪氣), healthy qi(正氣) attacks the origin of the disease in full force. Thus, all symptoms disappear at a time and various reactions occur which we can't accurately determine. So, we can call it 'Right action', 'Improving reaction' or 'Adjusting reaction'. Conclusions: It is difficult for us to predict whether a dizziness reaction will occur. Thus, we don't have to seek dizziness reaction blindly, and must distinguish dizziness reaction from side effects or toxic effects. So, we must pay more close attentions to symptom changes.

  • PDF