• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.2
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• pp.95-101
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• 1995

Experiments have been conducted to investigate the characteristics of formaldehyde and nitrous oxide formation from the catalytic reaction of methane. Catalysts used in the experiment were Pd. Pd/Pt/Rh loaded on ${\gamma}-Al_2O_3$ and ${\gamma}-Al_2O_3-La_2O_3$ monolith. In the catalytic reaction of methane. as the concentration of NO, $O_2$ and $CH_4$ increased, the formaldehyde emission was increased. The concentration of $N_2O$ increased as NO and CO increased. It was also found that the formaldehyde emission was produced by the gas reaction of methane in high temperature above 950K.

• Nuclear Engineering and Technology
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• v.50 no.1
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• pp.145-150
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• 2018

A new methodology, the crack-spallation model, has been developed to analyze gas-solid reactions dominated by crack growth inside of the solid reactant and spallation phenomena. The new model physically represents three processes of the reaction progress: (1) diffusion of gas reactant through pores; (2) growth of product particle in pores; and (3) crack and spallation of solid reactant. The validation of this method has been conducted by comparison of results obtained in an experiment for oxidation of $UO_2$ and the shrinking core model. The reaction progress evaluated by the crack-spallation model shows better agreement with the experimental data than that evaluated by the shrinking core model. To understand the trigger point during the reaction progress, a detailed analysis has been conducted. A parametric study also has been performed to determine mass diffusivities of the gas reactant and volume increase constants of the product particles. This method can be appropriately applied to the gas-solid reaction based on the crack and spallation phenomena such as the voloxidation process.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.461-464
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• 2005

As the research on the development of the lightweight concrete block by the hydro-thermal synthetic reaction mixed with the calcareous material and bottom ash that is used less among siliceous material, we studied on the physical and chemical characteristics in the changes of hydro-thermal synthetic reaction of lightweight concrete block compounded with the PP fiber to increase flexural toughness and to prevent fragility failure. The results of the experiment are as follow. According to the increase of hydro-thermal synthetic reaction and the fiber content, compressive and flexural strength increased. Despite the changes of the hydro-thermal synthetic reaction time, tobermorite was produced on each of the specimens similarly. However, the phase of tobermorite was changed in accordance with the changes of time. Also, $CaCo_{3}$ appeared on the surface of the 9 hour hardened specimen.

• The Korean Journal of Mycology
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• v.1 no.2
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• pp.9-14
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• 1973

Author investigated fluorence antibody reaction for the antigenic relationships between Asp niger group, Asp flavus and Asp parasiticus which was indicated as follows: 1. It was concluded that there are complete differences in the antigenic properties each other because it has not cross reaction, therefore identification of strains will be simpley classified. 2. A complete cross reaction between Asp flavus and Asp parasitic us in the Asp flavus groups existed, accordingly this reaction could not identified the strain and classified between Asp. flavus and Asp. parasiticus. 3. This experiment also followed with the separated each strains from the origin (Meju, Nuruk, ATCC, NRRL), but there no differences. From the above results, this method could be classified between Asp flavus group and Asp niger group in the genus Aspergillus, but classification of Asp. flavus and Asp. parasiticus should hardely conclude with this method.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.14 no.23
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• pp.37-46
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• 1991

This study deals with the designing of vehicle pedal considering simple reaction time of visual information. Because vehicle accidents may bring about fatal results, the vehicle design which is considered with safity is very important. Though the vehicle design considered with safity is important in the whole parts of vehicle, the designing of pedal which is directly connected the designing of pedal which can minimize reaction time to risk through simple experiments. In the experiments, the experience of driving, the location of brake pedal and the space between brake and accelerator pedal are considered. Using experiment equipment and IBM-PC, simple reaction time was measured. The data which was result from measurement was analyzed with SPSS/PC+. When brake pedal located right side and the space between brake and accelerator pedal was 35cm, reaction was minimized. Based on this results, the vehicle pedal should be designed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.3
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• pp.253-255
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• 1999

Reverse transcription and polymerase chain reaction (RT-PCR) assay was used to detect SMV strains. A pair of oligonucleotide primers were designed to include the cylindrical inclusion (CI) coding region between 4,176 to 5,560 nt. Amplification from the total RNA extracted from infected plants with SMV yielded a 1,385 bp DNA fragment. RT-PCR was shown to be $10^3$ times more sensitive than the ELISA assay and it could detect a virus in $10^{-6}$ dilution. Restriction enzyme analysis of RT- PCR products using EcoR I showed that SMV isolates were classified into six groups according to the patterns of restriction fragments.

• Applied Chemistry for Engineering
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• v.9 no.2
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• pp.268-272
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• 1998

Water leak phenomena in the liquid sodium which is a coolant of liquid metal reactor, were investigated by carrying out sodium-water reaction experiment. It was confirmed that sodium and water react each other by the analysis of material composition of aspecimen at the end of experiment. When steam of $100kg/cm^2$ was passed through the leak path of the specimen for 4 hours, reaction products from sodium-water reaction were observed on the leak site. However, re-opening phenomena were not observed at this condition. It was interpretted that the reaction product precipitated on leak path and thermal transient caused self-plugging and re-openning phenomena, respectively.

• Korean Journal of Veterinary Research
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• v.36 no.1
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• pp.169-179
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• 1996

This study was carried out to examine the role of small cells and oval cells in cholangiocarcinogenesis in the hamsters infected with Clonorchis(C) sinensis. Forty two female Syrian golden hamsters were divided into two groups. Group I was for the induction of the cholangiocarcinoma, which was infected orally with C sinensis and given dimethylnitrosamine(15ppm) in drinking water for 4 weeks. Group II was served as control. More than 5 heads of hamsters in each group were sacrificed at 4, 7, 11 and 15 weeks after the beginning of the experiment. The livers were examined histopathologically, electron microscopically and immunohistochemically. The results obtained were as follows; 1. Cholangiocarcinomas were occurred in 1 of 6 animals at 11 weeks and in 4 of 6 animals at 15weeks after the beginning of the experiment. 2. Small cells and oval cells were proliferated around the portal triads from 4 weeks and peaked at 11 weeks, and slightly decreased after then. 3. The strong positive reaction to the $\alpha$-fetoprotein was shown in many of small cells and oval cells. But ductlike oval cells, which were arranged rosette form, showed week positive reaction to the $\alpha$-fetoprotein. 4. Most of small cells and oval cells showed negative reaction to the cytokeratin. But weak positive reaction in ductlike oval cells, and moderate positive reaction in cholangiocarcinoma cells were observed. These results suggested that cholangiocarcinoma induced by infection of C sinensis was believed to originate from the proliferated small cells around the portal triads which would be able to differentiate to the oval cells, ductlike oval cells, and cholangiocarcinoma cells gradually.

• Journal of the Mineralogical Society of Korea
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• v.9 no.2
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• pp.71-81
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• 1996

Dissolution experiments were conducted to understand chemical nature of weathering of anorthosite from the Hadong area. Anorthosite and plagioclase from it were reacted with HCl or KOH solutions under various conditions concerning such as grain size, initial pH of solutions, and shaking Average composition of plagioclase used in the experiment was Na0.32Ca0.71Al1.71Si2.28O8.Under acidic conditions, solution pH increases rapidly in the initial stage and then gradually to reach palteau. Shaking agitates the reaction rate in the initial stage but does not affect after the system reached steady state. Ca and si concentrations show rapid increase and then gradual increase. Al concentration increases rapidly in the early stage and then decreases. Later decrease was interpreted as the precipitation of an Al-bearing material. Different dissolution rates of different constituents of plagioclase together the with precipitation of al-bearing material might be responsible for the non-stoichiometric dissolution of plagioclase.X-ray diffraction analyses on anorthosite before and after dissolution experiment show dissolution rates differ with different lattice planes of plagioclase. It suggests the crystallographic control on dissolution reaction. X-ray photoelectron spectroscopic result shows that the average composition of plagioclase surface reacted with HCL of initial pH 1.97 for 2000 hours is Na0.20Ca0.26Al1.7Si2.3O8. It means that Na- and Ca-depleted H-feldspar is developed without Al-depleted layer on the surface of plagioclase by reaction with HCl and that dissolution reaction takes place sparsely on the surface of plagioclase. Al and Si are dissolved preferentially over Ca from anorthosite powder in KHO solution. Reaction of acid-reacted anorthosite with KOH solution shows the same Si dissolution behavior as in the fresh anorthosite. This indicates that the Al-depleted and Si-enriched layer does not build up on the acid-reacted surface.

• Membrane Journal
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• v.15 no.4
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• pp.281-288
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• 2005

The hyaluronic acid (HA) with excellent biocompatibility can be combined with lactide, the ester dimer of polylactide, with good biodegradability to produce biocompatible materials applicable to drug delivery system. By freeze drying method, HA and lactide were crosslinked with crosslinking agent, 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide. Degree of lactide and EDC reaction was determined by the analysis of nuclear magnetic resonance (NMR) spectroscopy. The degree of lactide and EDC reaction increased and swelling ratio decreased as the mole ratio of lactide to HA or crosslinking agent concentration increased or reaction temperature decreased. The drug release experiment result from membranes having different degree of lactide reaction showed that drug release rate reduced in proportion to the degree of lactide reaction. The drug release experiment result from drugs having different hyrodphobicity showed that the more hydrophobic drug was released more slowly.