• 제목/요약/키워드: Chemical Experimental study

검색결과 2,597건 처리시간 0.034초

Membrane Contactors for Water Carbonation

  • Alessandra Criscuoli;Enrico Drioli
    • 멤브레인
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    • 제1권1호
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    • pp.59-59
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    • 1991
  • A theoretical and experimental study made in order to determine the performance of mem-brane contactors in water carbonation is presented. In particular on the basis of experimental results pre-viously obtained it has been derived an expression in which the effect of some parameters as temprera-ture water and CO₂ flow rate CO₂ pressure trans-membrane pressure on the performance of the process is taken into account. The study refers to hollow fiber membrane contactors used for the experimental tests. The main scope has been to verify if by membrane contactors it is possible to reach the same de-gree of water carbonation as by trditional methods (1-5 g/1) and to derive for the module used a cor-relation able to describe the performance of the process at several operating conditions. The high CO₂ removal observed confirms the interesting potentialties of membrane contactors also in gas streams purification.

Theoretical and Experimental 31P NMR and ESI-MS Study of Hg2+ Binding to Fenitrothion

  • Koo, In-Sun;Ali, Dildar;Yang, Ki-Yull;vanLoon, Gary W.;Buncel, Erwin
    • Bulletin of the Korean Chemical Society
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    • 제30권6호
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    • pp.1257-1261
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    • 2009
  • We present the theoretical and experimental results of $^{31}P$ NMR and low energy CID MS/MS study of $Hg^{2+}$ binding to fenitrothion (FN). The calculated $^{31}P$ NMR chemical shifts order for FN with $Hg^{2+}$ complex is in good agreement with experimental $^{31}P$ NMR chemical shifts order. The experimental and theoretical $^{31}P$ NMR study of organophosphorus pesticide with $Hg^{2+}$ gives to important information for organophosphorus pesticide metal complexes. ESI-MS and low energy CID MS/MS experiments of $Hg^{2+}$-FN complexes combined with accurate mass measurements give insight into the metal localization and allow unambiguous identification of fragments and hydrolysis products.

콘크리트의 내화학성에 관한 실험적 연구(II)-규사 분말을 치환한 모르터의 경우- (An Experimental Study on the Chemical Resistance of Concrete(II) -The case of mortar with silica sand particle-)

  • 윤보현;김제원;설광욱;김명재;부척량
    • 콘크리트학회지
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    • 제9권1호
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    • pp.153-163
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    • 1997
  • 본 논문은 규사 분말을 치환한 모르터의 내화학성에 관한 실험적 연구이다. 모르터 시험체에 대하여 모르터의 내화학성능 개선용 혼화재로서 규사 분말의 활용성 및 콘크리트 시험체의 내화학적 특성에 관한 예측 모델로서의 모르터 모델의사용 가능성 등을 검토하였다. 그결과 다음과 같은 결론을 얻을 수 있었다. 모르터 모델의 콘크리트 내화학성 예측 모델로서 사용 가능성 검토 결과, 혼화재의 종류 및 치환량에 따른 내화학성 실험 결과가 콘크리트의 실험 결과와 유사하게 나타나므로 콘크리트 시험체의 내화학성 예측 모델로서 활용이 가능하리라 사료된다.

Study of Retention in Micellar Liquid Chromatography on a C18 Column on the Basis of Linear Solvation Energy Relationships

  • Tian, Minglei;Row, Kyung-Ho
    • Bulletin of the Korean Chemical Society
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    • 제29권5호
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    • pp.979-984
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    • 2008
  • In this study, 8 solutes (aniline, caffeine, p-cresol, ethyl benzene, methylparaben, phenol, pyridine, and toluene) have been tested in terms of linear solvation energy relationships (LSER). Several micellar liquid chromatography (MLC) systems using cationic surfactant cetyltrimethylammonium bromide (CTAB) and a mixture of water with (methanol, n-propanol, and n-butanol) modifiers were characterized using the LSER solvation parameter model. The effects of the surfactant and modifier concentration on the retention in MLC were discussed. LSER model had demonstrated high potential to predict retention factors with high squared correlation coefficients ($r^2$ > 0.99). A comparison of predicted and experimental retention factors suggests that LSER formalism is able to reproduce adequately the experimental retention factors of the solutes studied in the different experimental conditions investigated. This model is a helpful tool to understand the solute-surfactant interactions and evaluate the retention characteristic of micellar liquid chromatography.

항암화학요법에 관한 개별교육이 암 환자의 삶의 질에 미치는 효과 (A Study on Effect of Individual Education about Chemical Therapy for Preventing Cancer on Quality of Life of Patient Who Suffers From Cancer)

  • 추연화;김경희
    • 종양간호연구
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    • 제4권2호
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    • pp.103-109
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    • 2004
  • The disease occurrence rate of the cancer is rapidly increased and It is becoming the main factor for the death The chemical therapy for preventing the cancer is recently used for many patients and thus extended the life of the patients. However, the side effect caused by the medical substances when performing the chemical therapy for preventing the cancer and the consequent mental and social problem are incurred to deteriorate the quality of the life. Therefore, it is needed to help the patient In order to reduce the above problems, and so this study was executed in order to examine the effect of the individual education on the quality of the life of the patients who are treated by the chemical therapy for preventing the cancer. The study was performed from Jan. 19. 2004 to Apr. 18. 2004 for the patients who were firstly treated by the chemical therapy for preventing the cancer in a university hospital located in the downtown in Seoul. The individual education on the chemical therapy for preventing the cancer was provided to 40 patients of the experimental group. The study plan is the experimental plan before and after the sole group, and it is the beginning experimental plan. The title of the booklet on the chemical therapy for preventing the cancer is "Cancer, The more you know, the more you can be cured", and the book was composed up of the side effect of the chemical therapy for preventing the cancer, treatment way for the side effect, and guide of the daily life. The survey with the questionnaire sheet was distributed to the experi- mental group before the education, the survey sheet was made out when they were hospitalized for 3-4 weeks after the education, and the data were examined by using SPSS statistical program with making our the survey questionnaires and the change of the quality of the life before and after the education of the patients who are treated by the chemical therapy for preventing the cancer was analyzed by using the parred t-test. The research result was verified that it has the meaningful that the quality of the life for the physical field, mental field, social field, and spiritual field after the individual education. The suggestion concluded by the above research result is as follows. First, there is the limitation to interpret the result since it was the beginning experimental plan for the sole group. Thus, it is suggested that the similar experimental plan should be executed with the expansion of the research subject and also with the contrast group. Second, it is suggested that the study on the change of the quality of the lifeaccording to the support of the individual education and family of the patients who are treated by the anti-cancer therapy.

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Computational Fluid Dynamics Study on Particle Rejection in Microfiltration

  • Nakao, Shin-ichi;Goto, Tomomasa;Tanaka, Nobuyuki;Yamamoto, Atsushi;Takaba, Hiromitsu
    • 한국막학회:학술대회논문집
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    • 한국막학회 2004년도 Proceedings of the second conference of aseanian membrane society
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    • pp.15-18
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    • 2004
  • Computational fluid dynamics (CFD) was applied to modeling particle dynamics in microfiltration (MF). The rejection properties of poly methylmethacrylate (PMMA) and polystyrene (PS) were calculated. Calculated rejection (R) of PMMA was independent with the porosity of the membrane, and the R was constant in the range of volume flux between $1\times 1-^{-4}-1\times 10^{-2}$ m/s. These observations were in quantity agreement with our experimental observations. The dependence of PMMA and PS rejection on the ratio of particle diameter and pore diameter were good agreement with the experimental values, which suggesting that the validity of CFD simulation to evaluate rejection of particle in MF membranes. Change of rejection of PMMA as a function of time was molded based on the CFD result which explained well the experimental observation.

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엑사이머 레이져를 이용한 실리콘웨이퍼의 미세가공

  • 윤경구;이성국;황경현
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1997년도 춘계학술대회 논문집
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    • pp.1058-1062
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    • 1997
  • Development of laser induced chemical etching technologt with KrF laser are carried out in this study for micromachining of silicon wafer. The paper is devoted to experimental identification of excimer laser induced mechanism of silicon under chlorine pressures(0.02~500torr). Experimental results on pulsed KrF excimer laser etching of silicon in chorine atmosphere are presented. Etching rate dependency on laser fluence and chlorine pressure are discussed on the basis of experimental analysis, it is concluded that accurate digital micro machining process of silicon wafer can achieved by KrF laser induced chemical etching technology.

Synthesis and Characterization of Alkyl Methacrylate-based Microgels by Experimental Design Method

  • Lee, Young-Keun;Jin, Fan-Long;Park, Soo-Jin
    • Bulletin of the Korean Chemical Society
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    • 제28권9호
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    • pp.1493-1498
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    • 2007
  • In this work, alkyl methacrylate-based microgels were synthesized by an experimental design method, and their sebum absorption characteristics were investigated. The results of fractional factorial experimentation indicated that the cross-linking agent content, solvent content, and stirring speed were the main parameters in the synthesis of the microgels. The suitable synthesis conditions were determined by the response surface design method. Through a study of the monomer and solvent effects, it was confirmed that the microgel shows the highest sebum absorption ratio when t-butyl methacrylate is used as a monomer or when acetone is used as a solvent. The optimal microgel synthesis conditions for cosmetic application were determined, and the resulting microgel had a mean particle size of 4.7 μm and a sebum absorption ratio of 435%.

31P NMR and ESI-MS Study of Fenitrothion-Copper Ion Complex: Experimental and Theoretical Study

  • Choi, Ho-June;Yang, Ki-Yull;Park, Jong-Keun;Koo, In-Sun
    • Bulletin of the Korean Chemical Society
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    • 제31권5호
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    • pp.1339-1342
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    • 2010
  • $^{31}P$ NMR and ESI-MS studies of $Cu^{2+}$ binding to Fenitrothion (FN) were performed by experimentally and theoretically. The calculated $^{31}P$ NMR chemical shifts for FN-$Cu^{2+}$ complexes are in good agreement with experimental chemical shifts in order, and the results present an important information for organophosphorus pesticide metal complexes. ESI-MS and low energy CID MS/MS experiments of FN-$Cu^{2+}$ complexes combined with accurate mass measurements give insight into the metal localization and allow unambiguous identification of fragments and hydrolysis products.

Calculation of $^{13}C, ^{15}N,\; and \;^{29}Si$ NMR Shielding Tensors for Selected X-Substituted Silatranes Using GIAO/CSGT-SCF

  • 김동희;이미정;오세웅
    • Bulletin of the Korean Chemical Society
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    • 제19권8호
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    • pp.847-851
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    • 1998
  • 13C, 15N, and 29Si NMR chemical shifts have been computed for selected X-substituted silatranes (X=Cl, F, H, CH3) using Gauge-Including Atomic Orbitals (GIAO) and Continuous Set of Gauge Transformations (CSGT) at the Hartree-Fock level of theory. The isotropic 13C chemical shifts are largely insensitive to substituent-induced structural changes. In this study, the isotropic 13C chemical shifts GIAO and CSGT calculations at the HF/6-31G and HF/6-31G* levels are sufficiently accurate to aid in experimental peak assignments. The isotropic 13C chemical shifts X-substituted silatranes at HF/6-31G* level are approximately 4 ppm different from the experimental values. In contrast, the isotropic 15N and 29Si chemical shifts and the chemical shielding tensors are quite sensitive to substituent-induced structural changes. These trends are consistent with those of the experiment. The 15N chemical shift parameters demonstrate a very clear correlation with Si-N distance, especially when we use the polarization function. Changes in anisotropy, 3a as well as in the 15N isotropic chemical shifts are due primarily to changes in the value of a.. But in case of "Si the correlations are not as clean as for the 15N chemical shift.