• Title/Summary/Keyword: Local reaction

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Effects of carbonation on hydration characteristics of ordinary Portland cement at pre-curing condition

  • Kim, Gwang Mok
    • Journal of Urban Science
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    • v.11 no.1
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    • pp.21-28
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    • 2022
  • Raman spectroscopy is effective to investigate functional groups via molecular vibration. The technique offers the structural information of compounds including subtle changes in the chemical composition of local atomic coordination without critical damage. Thus, the effect of carbonation on the hydration characteristics of Portland cement under pre-curing conditions for carbonation was investigated via Raman spectroscopy in the present study. Gaseous CO2 was injected within 60 seconds, and the reaction time was varied from 0 minute to 90 minutes. The test results indicated that the Ca/Si ratio of C-S-H reduced immediately after mixing and then the C-S-H with a relatively high Ca/Si ratio coexisted as the reaction time increased. The calcium carbonates formed in the present study included calcite and amorphous calcium carbonates. The test results via Raman spectroscopy provide valuable information about the carbonation characteristics of OPC under pre-curing conditions for carbonation.

Unsteady Flamelet Modeling of Turbulent Nonpremixed Flames (비정상 층류화염편 모델을 이용한 비예혼합 난류화염 해석)

  • Kim, Seong-Ku;Kang, Sung-Mo;Kim, Yong-Mo
    • 한국연소학회:학술대회논문집
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    • 2000.05a
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    • pp.133-141
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    • 2000
  • The present study is focused on modeling the transient behavior of the local flame structure which is especially important for slow reaction processes, such as NOx formation in the radiating flame field. The recently developed unsteady flamelet model has been applied to analyze a steady, turbulent jet flame. Numerical results are compared with experimental data and numerical results of the conventional steady flamelet model. The numerical result reveals that the unsteady flamelet model correctly predicts the nonequilibrium effect upsteam and the subsequent decay of the superequilibrium radical concentrations the further downstream.

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Unsteady Flamelet Modeling of Turbulent Nonpremixed Flames (비정상 층류화염편 모델을 이용한 비예혼합 난류화염 해석)

  • Kim, Seong-Ku;Kang, Sung-Mo;Seo, Bo-Sun;Kim, Yong-Mo
    • Journal of ILASS-Korea
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    • v.6 no.3
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    • pp.8-16
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    • 2001
  • The present study is focused on modeling the transient behavior of the local flame structure which is especially important for slow reaction processes, such as NOx formation in the radiating flame field. The unsteady flamelet model recently developed has been applied to analyze a steady, turbulent jet flame. Numerical results are compared with experimental data and numerical results of the conventional steady flamelet model. The numerical result reveals that the unsteady flamelet model correctly predicts the nonequilibrium effect upsteam and the subsequent decay of the superequilibrium radical concentrations further downstream.

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A Study on the Combustion Characteristics of Swirling Jet Combustor (선회분류 연소기의 연소특성에 관한 연구)

  • 심순용;손강호;이창식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.2
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    • pp.492-501
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    • 1994
  • This study is an analysis of the turbulent diffusion flame with swirl flow and the calculated results are compared with experimental data in case of various swirl numbers and air-fuel rations. The mathematical model is restricted to single-phase, diffusion controlled combustion with swirl flow. Values of local flow properties were obtained by solving appropriate differential equation for continuity, momentum, stagnation enthalpy, concentration, turbulence energy, dissipation rate of turbulence energy, and the mean square of concentration fluctuation. The method is proposed for calculating the local probability of chemical reaction based on the use of the probability density function for the mixture fraction.

A Histopathological Observation on the Local Side Reaction following the Intramuscular Injection of Iron Preparations in Guinea pigs (철분근육주사후에 일어나는 국소자극반응에 관한 병리조직학적 관찰)

  • Kim, Soon-Bok
    • Korean Journal of Veterinary Research
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    • v.23 no.2
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    • pp.179-182
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    • 1983
  • This study was conducted to observe the local irritation histopathologically following the intramuscular injection of iron preparations in guinea pigs. Necropsy findings were edema, hemorrhage and darkish brown pigmentation around the injection sites. On the microscopic examination, the muscle fibers near the injection sites became pale staining or uniformly eosinophilic, indicating necrosis of the fibers, which were occasionally filled with granular bluish-staining material. The nuclei were swollen or pyknotic. Infiltrations of heterophils and macrophages containing iron were evident around the necrotized tissues and the injected iron compounds. Fibrosis was often seen between the affected muscle fibers, and this change was considered as secondary inflammatory process.

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Plasma cell Granuloma: one case report (혈장세포 육아종[보고 1예])

  • Kwack, Yeong-Tae;Park, Ju-Cheol;Yoo, Seh-Young
    • Journal of Chest Surgery
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    • v.14 no.3
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    • pp.225-227
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    • 1981
  • A 31-year-old female visited O.P.D. of internal medicine, Kyung Hee Medical center, with the chief complaint of generalized weakness and headache. She took a routine chest P-A and there was a 6.5 x 7.5 cm sized round mass in the right middle lung field. She admitted to the Dept. of Thoracic and Cardiovascular Surgery under the impression of malignant bronchogenic carcinoma with the remit of bronchoscopy and sputum cytology and tomogram. Middle and lower lobectomy of right lung was performed and postoperative surgical biopsy revealed out the plasma cell granuloma. The plasma cell granuloma may occur as a solitary nodule in the lung or be associated with systemic disease, plasma protein imbalance, or nonspecific local inflammatory reaction . More than two third of the reported patients were less than 30 year of age. Grossly the lesion appears reddish-brown and microscopic features include pallisade or a cartwheel distribution of plasma cells with Russel bodies and amyloid. Local excision or lobectomy has been curative in most cases.

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Molecular Networks via Coordination Polymerization. Synthesis and Characterization of 2-D Polymeric Cobalt(II) Compounds Containing 3,3'-Dipyridyl Ether Series

  • Jeong, Ok Sang;Kim, Yun Ju;Lee, Yeong A;Lee, Jae Gyeong;Yu, Gyeong Ho
    • Bulletin of the Korean Chemical Society
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    • v.21 no.1
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    • pp.39-43
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    • 2000
  • New coordination polymers of general form, $$[CoL_2X_2]_n$$ (L = 3,3'-oxybis(pyridine) (obp), 1,4-bis(3-pyri-doxy) benzene (bpob); X = Cl, NCS), have been prepared via a slow diffusion method. The reaction of the present linkers with cobalt(II) ion affords infinite 2-dimensional sheet products. For $[Co(obp) $_2Cl_2]_n$$, the local geometry of the cobalt center is an octahedral arrangement with four nitrogen donors and two chlorine ions in trans positions. $$[Co(bpob)_2(NCS)_2]_n$$ has provided a similar structure: the local geometry of the cobalt atom is an octahedral arrangement with four pyridine units and two NCS groups in transpositions. The obp and bpob linkers connect two cobalt(II) ions defining the edges of 40- and 60-membered $[Co(II)]_4$ ring, respectively. Thermal analyses of the coordination polymers show significant thermal behavior associated with the characteristic structures.

An Analysis on the Characteristic and Origin of the Exhaustion Method (실진법의 특성과 기원에 대한 분석)

  • Park, Sun-Yong
    • Journal for History of Mathematics
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    • v.32 no.1
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    • pp.27-44
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    • 2019
  • This study analyses and discusses on the characteristic and the origin of the exhaustion method caused by the controversy over whether that method succeeded to the Antiphone's complete exhaustion idea and whether that method is similar to the method of limits. First, this study analyses 'principle of exhaustion method' which play an important role in that method in order to grasp the local characteristic of it. And this study speculates the origin of the exhaustion method by considering the time and situation of appearance and looking through the local characteristic of it. Also, this study takes a view of the overall characteristic of the exhaustion method by inquiring into the process of actual application of 'principle of exhaustion method' in a proof. As these results, this study reveals that the exhaustion method uprose not as a succession of Antiphone's idea but as a reaction to its idea, and that the exhaustion method has the recognized character of 'finitude' as distinct from the method of limits.

A Holistic View of the Japanese Occupation of Southeast Asia

  • Dhont, Frank
    • SUVANNABHUMI
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    • v.8 no.1
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    • pp.77-94
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    • 2016
  • The paper examined Southeast Asia as a whole and focused on similarities among countries composing what is now known as the Association of Southeast Asian Nations (ASEAN). In order to determine these similarities, the analysis focused on the fact that during World War II the whole of Southeast Asia was occupied by one political power: Japan. The policies the Japanese implemented in the region were to a degree very similar in terms of pressures and tensions that occurred in the different countries. The paper argues that these pressures and the responses of the various peoples of Southeast Asia instilled a nucleus of common identity in Southeast Asia as a whole. Basically, the policies that the Japanese implemented all over Southeast Asia were the following: the setting up regional administrations; the extraction of resources and emphasis on local self-sufficiency; the implementation of cultural Japanization; and local indigenization policies. The Southeast Asian responses that crystalized this joint Southeast Asian identity may be described as: accommodating and resisting the Japanese; commemorating portraying; and collectively remembering the era. The process of action and reaction between Japan and Southeast Asia was formative of this joint Southeast Asian identity.

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Syncope and Unconsciousness after Intravenous Injection of Antibiotics in Patient with Cerebrovascular Accident : Report of a Case (뇌졸중 환자에서 항생제 정주 후 유발된 실신과 의식소실: 증례보고)

  • Yoo, Jae-Ha;Son, Jeong-Seog;Kim, Jong-Bae
    • Journal of The Korean Dental Society of Anesthesiology
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    • v.12 no.4
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    • pp.215-221
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    • 2012
  • The loss of consciousness in the dental office have many causes, such as, vasodepressor syncope, drug administration, orthostatic hypotension, epilepsy, hypoglycemic reaction, acute adrenal insufficiency, acute allergic reaction, acute myocardial infarction, cerebrovascular accident, hyperglycemic reaction and hyperventilation. Patients have fainted during all phases of dental care: during tooth extraction and other surgical procedures, during local anesthetic injections, or during procedures such as venipuncture, on being seated in the dental chair, and even on first entering the dental office. If an elderly patient with known cardiovascular or cerebrovascular problems experiences a syncopal episode, differentiation from cerebrovascular insufficiency of more serious etiology, such as cerebrovascular accident, must be considered. And anaphylactic shock is also suggested during intravenous drug administration. This is a case report of syncope care during venous injection of cephalosporin in patient with cerebrovascular accident.