• Title/Summary/Keyword: Catalytic test

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Effect of ZnCl2 Co-catalyst in the Synthesis of Dimethyl Carbonate from Ethylene Carbonate and Methanol by Using Base Catalysts (염기 촉매를 이용한 디메틸카보네이트 합성에서 ZnCl2 조촉매의 영향)

  • Kim, Dong-Woo;Park, Moon-Seok;Kim, Moon-Il;Park, Dae-Won
    • Korean Chemical Engineering Research
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    • v.50 no.2
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    • pp.217-222
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    • 2012
  • The synthesis of dimethyl carbonate(DMC) is a promising reaction for the use of naturally abundant carbon dioxide. DMC has gained considerable interest owing to its versatile chemical reactivity and unique properties such as high oxygen content, low toxicity, and excellent biodegradability. In this study, the synthesis of DMC through the transesterification of ethylene carbonate(EC) with methanol was investigated by using ionic liquid and metal oxide catalysts. The screening test of different catalysts revealed that choline hydroxide ([Choline][OH]) and 1-n-butyl-3-methyl imidazolium hydroxide([BMIm][OH]) had better catalytic performance than metal salts catalysts such as MgO, ZnO and CaO. The effects of reaction parameters such as reaction temperature, MeOH/EC mole ratio, and carbon dioxide pressure on the reactivity of [Choline][OH] catalyst were discussed. High temperature and high MeOH/EC mole ratio were favorable for high conversion of EC. However, the yield of DMC showed a maximum when carbon dioxide pressure was 1.34 MPa, and then it decreased for higher carbon dioxide pressure. Zinc chloride($ZnCl_2$) was used as co-catalyst with the ionic liquid catalyst. The mixed catalyst showed a synergy effect on the EC conversion and DMC yield probably due to the acid-base properties of the catalysts.

Removal of NOx from Graphene based Photocatalyst Ceramic Filter (그래핀 기반 광촉매 담지 세라믹필터에서 질소산화물(NOx)의 제거)

  • Kim, Yong-Seok;Kim, Young-Ho
    • Applied Chemistry for Engineering
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    • v.33 no.6
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    • pp.600-605
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    • 2022
  • In this study, nitrogen oxide (NOx) removal experiments were performed using a graphene based ceramic filter coated with a V2O5-WO3-TiO2 catalyst. Graphene oxide (GO) was prepared by Hummer's method using graphite, and the reduced graphene oxide was produced by reducing with hydrazine (N2H4). Vanadium (V), Tungsten (W), and Titanium (Ti) were coated by the sol-gel method, and then a metal oxide-supported filter was prepared through a calcination process at 350 ℃. A NOx removal efficiency test was performed for the catalytic ceramic filters with UV light in a humid condition. When graphene oxide (GO) and reduced graphene oxide (rGO) were present on the filter, the NOx removal efficiency was superior to that of the conventional ceramic filter. Most likely, this is due to an improvement in the adsorption properties of NOx molecules on graphene coated surfaces. As the concentration of graphene increased, higher NOx removal efficiency was confirmed.

Sodium Salicylate(NaSaL) Induces Apoptosis of NCI-H1299 Lung Carcinoma Cells via Activation Caspase-3 Protease (NCI-H1299 폐암 세포주에서 Caspase-3 Protease 활성을 통한 Sodium Salicylate(NaSaL)의 세포고사)

  • Shim, Hyeok;Yang, Sei-Hoon;Bak, Sang-Myeon;Jeong, Eun-Taik
    • Tuberculosis and Respiratory Diseases
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    • v.53 no.5
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    • pp.485-496
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    • 2002
  • Background : Nonsteroidal anti-inflammatory drugs (NSAIDs) are useful in the chemoprevention of colon cancers. Continuous NSAID use results in a 40% to 50% reduction in the relative risk of colorectal cancer. The precise mechanism by which NSAIDs prevent and/or cause the regression of colorectal tumors is not known. Some investigators have reported that certain NSAIDs induce apoptosis and alter the expression of the cell cycle regulatory genes in some carcinoma cells when administered at a relatively high concentration. However, the possibility of NSAIDs application as chemopreventive agents in lung cancers remains to be elucidated. To address this question, the human lung cancer cell line NCI-H1299 was used to investigate whether or not NSAIDs might induce the apoptotic death of NCI-H1299 cells. Methods : A viability test was carried out using a MTT assay. Apoptosis was measured by flow cytometric analysis and unclear staining(DAPI). The talytic activity of the caspase family was measured by the fluirigenic cleavage of biosubstrates. To define the mechanical basis of apoptosis, western blot was performed to analyze the expression of the death substrates(PARP and ICAD). Results : NaSaL significantly decreased the viability of the NCI-H1299 cells, which was revealed as apoptosis characterized by an increase in the $subG_0/G_1$ population and unclear fragmentation. The catalytic activity of caspase-3 protease began to increase after 24 Hr and reached a peak 30 Hr after treatment with 10 mM NaSaL. In contrast, caspase-6, 8, and 9 proteases did not have a significantly altered enzymatic activity. Consistent with activation of caspase-3 protease, NaSaL induced the cleavage of the protease biosubstrate. Conclusion : NaSaL induces the apoptotic death of NCI-H1299 human lung cancer cells via the activation of caspase-3 protease.

Chemical Synthesis and Orientation Disruption Bioassay of Sex Pheromone of the Oriental Fruit Moth, Grapholita molests (Busck) (복숭아순나방(Grapholita molests) 성페로몬 합성과 유인력 교란생물검정)

  • Kim, Yong-Gyun;Bae, Sung-Woo;Bae, Soo-Il;Yoon, Hyang-Mi;Hong, Yong-Pyo
    • Korean journal of applied entomology
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    • v.45 no.3 s.144
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    • pp.309-316
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    • 2006
  • Three sex pheromone components (cis-8-dodecenyl acetate (Z12Ac), trans-8-dodecenyl acetate (E12Ac), cis-8-dodecenol (Z12OH)) of the Oriental fruit moth, Grapholita molesta, were chemically synthesized. Especially to increase the composition of cis-stereoisomer, a triple bond intermediate was hydrogenated at $-20^{\circ}C$ with catalytic $Pd/BaSO_{4}$. The resulting product consisted of the acetates with a stereoisomer ratio in 92:8 (Z:E). The biological activity of the synthesized pheromone compounds was analyzed both in male responses and orientation disruption. The indoor pheromone effect was determined by male flight behavior showing wing movement in response to lure. Different mixtures of the synthetic pheromone components were prepared by mixing acetate and alcohol components in 100:0, 99:1, and 90:10 (g/g) and tested with a comparison of a standard commercial pheromone lure. The highest pheromone effect was observed in only acetate mixture (100:0) and the effect was reduced with the addition of the alcohol component. This indoor pheromone effect could be observed in field monitoring trial, in which 100:0 mixture showed the highest trap catches. Orientation disruption assay was conducted indoor by using a cage, in which the center had a commercial lure on sticky plate and the four candidates were placed at 6 cm away from the central lure on each of four directions. Test males were released to the arena during overnight (12 h) and then the caught males on the sticky plate were counted. The synthesized pheromone as well as the commercial pheromone showed 100% orientation disruption. However, the orientation disruption effect was reduced with decrease in the number of the surrounding disrupting pheromone baits. These results clearly suggest that the synthesized sex pheromone of G. molesta is biologically active and can be used for field mating disruption.

Oxidative Desulfurization of Marine Diesel Using Keggin Type Heteropoly Acid Catalysts (Keggin형 헤테로폴리산 촉매를 이용한 선박용 경유의 산화 탈황)

  • Oh, Hyeonwoo;Woo, Hee Chul
    • Clean Technology
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    • v.25 no.1
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    • pp.91-97
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    • 2019
  • Oxidative desulfurization (ODS) has received much attention in recent years because refractory sulfur compounds such as dibenzothiophenes can be oxidized selectively to their corresponding sulfoxides and sulfones, and these products can be removed by extraction and adsorption. In this work, The oxidative desulfurization of marine diesel fuel was performed in a batch reactor with hydrogen peroxide ($H_2O_2$) in the presence of various supported heteropoly acid catalysts. The catalysts were characterized by XRD, XRF, XPS and nitrogen adsorption isotherm techniques. Based on the sulfur removal efficiency of promising silica supported heteropoly acid catalysts, the ranking of catalytic activity was: $30\;H_3PW_{12}/SiO_2$ > $30\;H_3PMo_{12}/SiO_2$ > $30\;H_4SiW_{12}/SiO_2$, which appears to be related with their intrinsic acid strength. The $30\;H_3PW_{12}/SiO_2$ catalyst showed the highest initial sulfur removal efficiency of about 66% under reaction conditions of $30^{\circ}C$, $0.025g\;mL^{-1}$ (cat./oil), 1 h reaction time. However, through the recycle test of the $H_3PW_{12}/SiO_2$ catalyst, significant deactivation was observed, which was attributed to the elution of the active component $H_3PW_{12}$. By introducing cesium cation ($Cs^+$) into the $H_3PW_{12}/SiO_2$ catalyst, the stability of the catalyst was improved with changing the solubility, and the $Cs^+$ ion exchanged catalyst could be recycled for at least five times without severe elution.

CO2 Methanation Characteristics over Ni Catalyst in a Pressurized Bubbling Fluidized Bed Reactor (가압 기포 유동층 반응기에서의 Ni계 촉매 CO2 메탄화 특성 연구)

  • Son, Seong Hye;Seo, Myung Won;Hwang, Byung Wook;Park, Sung Jin;Kim, Jung Hwan;Lee, Do Yeon;Go, Kang Seok;Jeon, Sang Goo;Yoon, Sung Min;Kim, Yong Ku;Kim, Jae Ho;Ryu, Ho Jeong;Rhee, Young Woo
    • Korean Chemical Engineering Research
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    • v.56 no.6
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    • pp.871-877
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    • 2018
  • Storing the surplus energy from renewable energy resource is one of the challenges related to intermittent and fluctuating nature of renewable energy electricity production. $CO_2$ methanation is well known reaction that as a renewable energy storage system. $CO_2$ methanation requires a catalyst to be active at relatively low temperatures ($250-500^{\circ}C$) and selectivity towards methane. In this study, the catalytic performance test was conducted using a pressurized bubbling fluidized bed reactor (Diameter: 0.025 m and Height: 0.35 m) with $Ni/{\gamma}-Al_2O_3$ (Ni70%, and ${\gamma}-Al_2O_3$30%) catalyst. The range of the reaction conditions were $H_2/CO_2$ mole ratio range of 4.0-6.0, temperature of $300-420^{\circ}C$, pressure of 1-9 bar, and gas velocity ($U_0/U_{mf}$) of 1-5. As the $H_2/CO_2$ mole ratio, temperature and pressure increased, $CO_2$ conversion increases at the experimental temperature range. However, $CO_2$ conversion decreases with increasing gas velocity due to poor mixing characteristics in the fluidized bed. The maximum $CO_2$ conversion of 99.6% was obtained with the operating condition as follows; $H_2/CO_2$ ratio of 5, temperature of $400^{\circ}C$, pressure of 9 bar, and $U_0/U_{mf}$ of 1.4-3.

An Intervention Study on Integration of Family Planning and Maternal/Infant Care Services in Rural Korea (가족계획과 모자보건 통합을 위한 조산원의 투입효과 분석 -서산지역의 개입연구 평가보고-)

  • Bang, Sook;Han, Seung-Hyun;Lee, Chung-Ja;Ahn, Moon-Young;Lee, In-Sook;Kim, Eun-Shil;Kim, Chong-Ho
    • Journal of Preventive Medicine and Public Health
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    • v.20 no.1 s.21
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    • pp.165-203
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    • 1987
  • This project was a service-cum-research effort with a quasi-experimental study design to examine the health benefits of an integrated Family Planning (FP)/Maternal & Child health (MCH) Service approach that provides crucial factors missing in the present on-going programs. The specific objectives were: 1) To test the effectiveness of trained nurse/midwives (MW) assigned as change agents in the Health Sub-Center (HSC) to bring about the changes in the eight FP/MCH indicators, namely; (i)FP/MCH contacts between field workers and their clients (ii) the use of effective FP methods, (iii) the inter-birth interval and/or open interval, (iv) prenatal care by medically qualified personnel, (v) medically supervised deliveries, (vi) the rate of induced abortion, (vii) maternal and infant morbidity, and (viii) preinatal & infant mortality. 2) To measure the integrative linkage (contacts) between MW & HSC workers and between HSC and clients. 3) To examine the organizational or administrative factors influencing integrative linkage between health workers. Study design; The above objectives called for quasi-experimental design setting up a study and control area with and without a midwife. An active intervention program (FP/MCH minimum 'package' program) was conducted for a 2 year period from June 1982-July 1984 in Seosan County and 'before and after' surveys were conducted to measure the change. Service input; This study was undertaken by the Soonchunhyang University in collaboration with WHO. After a baseline survery in 1981, trained nurses/midwives were introduced into two health sub-centers in a rural setting (Seosan county) for a 2 year period from 1982 to 1984. A major service input was the establishment of midwifery services in the existing health delivery system with emphasis on nurse/midwife's role as the link between health workers (nurse aids) and village health workers, and the referral of risk patients to the private physician (OBGY specialist). An evaluation survey was made in August 1984 to assess the effectiveness of this alternative integrated approach in the study areas in comparison with the control area which had normal government services. Method of evaluation; a. In this study, the primary objective was first to examine to what extent the FP/MCH package program brought about changes in the pre-determined eight indicators (outcome and impact measures) and the following relationship was first analyzed; b. Nevertheless, this project did not automatically accept the assumption that if two or more activities were integrated, the results would automatically be better than a non-integrated or categorical program. There is a need to assess the 'integration process' itself within the package program. The process of integration was measured in terms of interactive linkages, or the quantity & quality of contacts between workers & clients and among workers. Intergrative linkages were hypothesized to be influenced by organizational factors at the HSC clinic level including HSC goals, sltrurture, authority, leadership style, resources, and personal characteristics of HSC staff. The extent or degree of integration, as measured by the intensity of integrative linkages, was in turn presumed to influence programme performance. Thus as indicated diagrammatically below, organizational factors constituted the independent variables, integration as the intervening variable and programme performance with respect to family planning and health services as the dependent variable: Concerning organizational factors, however, due to the limited number of HSCs (2 in the study area and 3 in the control area), they were studied by participatory observation of an anthropologist who was independent of the project. In this observation, we examined whether the assumed integration process actually occurred or not. If not, what were the constraints in producing an effective integration process. Summary of Findings; A) Program effects and impact 1. Effects on FP use: During this 2 year action period, FP acceptance increased from 58% in 1981 to 78% in 1984 in both the study and control areas. This increase in both areas was mainly due to the new family planning campaign driven by the Government for the same study period. Therefore, there was no increment of FP acceptance rate due to additional input of MW to the on-going FP program. But in the study area, quality aspects of FP were somewhat improved, having a better continuation rate of IUDs & pills and more use of effective Contraceptive methods in comparison with the control area. 2. Effects of use of MCH services: Between the study and control areas, however, there was a significant difference in maternal and child health care. For example, the coverage of prenatal care was increased from 53% for 1981 birth cohort to 75% for 1984 birth cohort in the study area. In the control area, the same increased from 41% (1981) to 65% (1984). It is noteworthy that almost two thirds of the recent birth cohort received prenatal care even in the control area, indicating that there is a growing demand of MCH care as the size of family norm becomes smaller 3. There has been a substantive increase in delivery care by medical professions in the study area, with an annual increase rate of 10% due to midwives input in the study areas. The project had about two times greater effect on postnatal care (68% vs. 33%) at delivery care(45.2% vs. 26.1%). 4. The study area had better reproductive efficiency (wanted pregancies with FP practice & healthy live births survived by one year old) than the control area, especially among women under 30 (14.1% vs. 9.6%). The proportion of women who preferred the 1st trimester for their first prenatal care rose significantly in the study area as compared to the control area (24% vs 13%). B) Effects on Interactive Linkage 1. This project made a contribution in making several useful steps in the direction of service integration, namely; i) The health workers have become familiar with procedures on how to work together with each other (especially with a midwife) in carrying out their work in FP/MCH and, ii) The health workers have gotten a feeling of the usefulness of family health records (statistical integration) in identifying targets in their own work and their usefulness in caring for family health. 2. On the other hand, because of a lack of required organizational factors, complete linkage was not obtained as the project intended. i) In regards to the government health worker's activities in terms of home visiting there was not much difference between the study & control areas though the MW did more home visiting than Government health workers. ii) In assessing the service performance of MW & health workers, the midwives balanced their workload between 40% FP, 40% MCH & 20% other activities (mainly immunization). However, $85{\sim}90%$ of the services provided by the health workers were other than FP/MCH, mainly for immunizations such as the encephalitis campaign. In the control area, a similar pattern was observed. Over 75% of their service was other than FP/MCH. Therefore, the pattern shows the health workers are a long way from becoming multipurpose workers even though the government is pushing in this direction. 3. Villagers were much more likely to visit the health sub-center clinic in the study area than in the control area (58% vs.31%) and for more combined care (45% vs.23%). C) Organization factors (admistrative integrative issues) 1. When MW (new workers with higher qualification) were introduced to HSC, it was noted that there were conflicts between the existing HSC workers (Nurse aids with less qualification than MW) and the MW for the beginning period of the project. The cause of the conflict was studied by an anthropologist and it was pointed out that these functional integration problems stemmed from the structural inadequacies of the health subcenter organization as indicated below; i) There is still no general consensus about the objectives and goals of the project between the project staff and the existing health workers. ii) There is no formal linkage between the responsibility of each member's job in the health sub-center. iii) There is still little chance for midwives to play a catalytic role or to establish communicative networks between workers in order to link various knowledge and skills to provide better FP/MCH services in the health sub-center. 2. Based on the above findings the project recommended to the County Chief (who has power to control the administrative staff and the technical staff in his county) the following ; i) In order to solve the conflicts between the individual roles and functions in performing health care activities, there must be goals agreed upon by both. ii) The health sub·center must function as an autonomous organization to undertake the integration health project. In order to do that, it is necessary to support administrative considerations, and to establish a communication system for supervision and to control of the health sub-centers. iii) The administrative organization, tentatively, must be organized to bind the health worker's midwive's and director's jobs by an organic relationship in order to achieve the integrative system under the leadership of health sub-center director. After submitting this observation report, there has been better understanding from frequent meetings & communication between HW/MW in FP/MCH work as the program developed. Lessons learned from the Seosan Project (on issues of FP/MCH integration in Korea); 1) A majority or about 80% of the couples are now practicing FP. As indicated by the study, there is a growing demand from clients for the health system to provide more MCH services than FP in order to maintain the achieved small size of family through FP practice. It is fortunate to see that the government is now formulating a MCH policy for the year 2,000 and revising MCH laws and regulations to emphasize more MCH care for achieving a small size family through family planning practice. 2) Goal consensus in FP/MCH shouBd be made among the health workers It administrators, especially to emphasize the need of care of 'wanted' child. But there is a long way to go to realize the 'real' integration of FP into MCH in Korea, unless there is a structural integration FP/MCH because a categorical FP is still first priority to reduce the rate of population growth for economic reasons but not yet for health/welfare reasons in practice. 3) There should be more financial allocation: (i) a midwife should be made available to help to promote the MCH program and coordinate services, (in) there should be a health sub·center director who can provide leadership training for managing the integrated program. There is a need for 'organizational support', if the decision of integration is made to obtain benefit from both FP & MCH. In other words, costs should be paid equally to both FP/MCH. The integration slogan itself, without the commitment of paying such costs, is powerless to advocate it. 4) Need of management training for middle level health personnel is more acute as the Government has already constructed 90 MCH centers attached to the County Health Center but without adequate manpower, facilities, and guidelines for integrating the work of both FP and MCH. 5) The local government still considers these MCH centers only as delivery centers to take care only of those visiting maternity cases. The MCH center should be a center for the managment of all pregnancies occurring in the community and the promotion of FP with a systematic and effective linkage of resources available in the county such as i.e. Village Health Worker, Community Health Practitioner, Health Sub-center Physicians & Health workers, Doctors and Midwives in MCH center, OBGY Specialists in clinics & hospitals as practiced by the Seosan project at primary health care level.

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