• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.2
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• pp.169-177
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• 2020

Here, the stability of stainless steel 316 (SS-316) was investigated to identify its applicability in the oxide reduction process, as a component in related equipment, to produce a complicated gas mixture composed of O₂ and Cl₂ under an argon (Ar) atmosphere. The effects of the mixed gas composition were investigated at flow rates of 30 mL/min O₂, 20 mL/min O₂ + 10 mL/min Cl₂, 10 mL/min O₂ + 20 mL/min Cl₂, and 30 mL/min Cl₂, each at 600℃, during a constant argon flow rate of 170 mL/min. It was found that the corrosion of SS-316 by the chlorine gas was suppressed by the presence of oxygen, while the reaction proceeded linearly with the reaction time regardless of gas composition. Surface observation results revealed an uneven surface with circular pits in the samples that were fed mixed gases. Thermodynamic calculations proposed the combination of Fe and Ni chlorination reactions as an explanation for this pit formation phenomenon. An exponential increase in the corrosion rate was observed with an increase in the reaction temperature in a range of 300 ~ 600℃ under a flow of 30 mL/min Cl₂ + 170 mL/min Ar.

• Clinical and Experimental Pediatrics
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• v.59 no.1
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• pp.43-46
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• 2016

We present a case of tuberculosis-associated hemophagocytic lymphohistiocytosis in a 14-year-old girl. The patient presented with weight loss, malaise, fatigue, prolonged fever, and generalized lymphadenopathy. Laboratory investigation revealed pancytopenia (white blood cells, $2,020cells/{\mu}L$; hemoglobin, 10.2 g/dL; platelets, $52,000cells/{\mu}L$), hypertriglyceridemia (229 mg/dL), and hyperferritinemia (1,420 ng/mL). Bone marrow biopsy showed a hypocellular bone marrow with a large numbers of histiocytes and marked hemophagocytosis; based on these findings, she was diagnosed with hemophagocytic lymphohistiocytosis. Polymerase chain reaction (PCR) with both the bone marrow aspiration and sputum samples revealed the presence of Mycobacterium tuberculosis. Antitubercular therapy with immune modulation therapy including dexamethasone and intravenous immunoglobulin was initiated. The results of all laboratory tests including bone marrow biopsy and PCR with both the bone marrow aspiration and sputum samples were normalized after treatment. Thus, early bone marrow biopsy and the use of techniques such as PCR can avoid delays in diagnosis and improve the survival rates of patients with tuberculosis-associated hemophagocytic lymphohistiocytosis.

• Journal of the Korean Society of Safety
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• v.25 no.1
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• pp.17-21
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• 2010

The chemistry and ignition delay of hydrogen/air/HFP premixed mixtures was investigated numerically with unsteady perfectly stirred reactor(PSR). The detailed chemistry of 93 species and 817 reaction mechanism was introduced for hydrogen/air/HFP mixtures. The results shows the temporal concentration variations of major or reactants such as hydrogen and oxygen during autoignition were similar to the spatial distribution of premixed flame while water vapor produced at the ignition temperature was decomposed later, which can be clarified with the relate species production rates that the the re-growth (or shoulder) of OH concentration is a result of F radicals attacking $H_20$ forming OH and HF. For the stoichiometric $H_2$/air mixture inhibited by 20% HFP, HFP thermal decomposition reaction prevails over the radical attack such as H at initial stage. Even though relatively large HFP addition contributes to delay the ignition, chemical effect on the ignition delay is not effective because of late thermal decomposition of HFP. The most small ignition delay was observed at a slightly fuel lean condition ($\phi$ = 0.9), and temperature dependency of ignition delay was clearly shown near 900 K.

• Carbon letters
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• v.12 no.4
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• pp.229-235
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• 2011

Isotactic polyacrylonitrile (PAN) with triad isotacticity of 0.53, which was determined by $^{13}C$ NMR, using dialkylmagnesium as an initiator, was successfully synthesized. Isothermal treatment of iso-PAN was conducted in air at 200, 220, 250 and $280^{\circ}C$. Structural evolutions and chemical changes were studied with Fourier transformation infrared and wide-angle X-ray diffraction during stabilization. A new parameter $CNF={I_{2240cm}}^{-1}/ ({I_{1595cm}}^{-1}+f^*{I_{1595cm}}^{-1})$ was defined to evaluate residual nitrile groups. Crystallinity and crystal size were calculated with X-ray diffraction dates. The results indicated that the nitrile groups had partly converted into a ladder structure as stabilization proceeded. The rate of reaction increased with treatment temperature; crystallinity and crystal size decreased proportionally to pyrolysis temperature. The iso-conversional method coupled with the Kissinger and Flynn-Wall-Ozawa methods were used to determine kinetic parameters via differential scanning calorimetry analysis with different heating rates. The active energy of the reaction was 171.1 and 169.1 kJ/mol, calculated with the two methods respectively and implied the sensitivity of the reaction with temperature.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.31-32
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• 2011

Granulated slag from metal industries and fly ash from the combustion of coal are industrial by-products that have been widely used as mineral admixtures in normal and high strength concrete. Due to the reaction between calcium hydroxide and fly ash or slag, the hydration of concrete containing fly ash or slag is much more complex compared with that of Portland cement. In this paper, the production of calcium hydroxide in cement hydration and its consumption in the reaction of mineral admixtures is considered in order to develop a numerical model that simulates the hydration of concrete containing fly ash or slag. The heat evolution rates of fly ash- or slag-blended concrete is determined by the contribution of both cement hydration and the reaction of the mineral admixtures. Furthermore, the temperature distribution and temperature history in hardening blended concrete are evaluated based on the degree of hydration of the cement and the mineral admixtures. The proposed model is verified through experimental data on concrete with different water-to-cement ratios and mineral admixture substitution ratios.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.243-246
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• 2004

Boron Phosphide films were deposited on (111) Si substrate at $650^{\circ}C$, by the reaction of $B_2H_6$ with PH, using APCVD. $N_2$ was carried out as carrier gas. The optimal gas rates were 20 ml/min for B2H6, 60 ml/min for PH3 and 1 l/min for N2. After as grown the films were insitu annealed fur 1hour in $N_2$ ambient at $550^{\circ}C$ and measured. The measurement of AFM shows that the average surface roughness is $10.108{\AA}$ for the reaction temperature at $450^{\circ}C$ and $29.626{\AA}$ fur the reaction temperature at $650^{\circ}C$. The measurement of XRD shows that the films have the orientation of(1 0 1). Also, the measurement of AES is shown that the films have $B_{13}P_2$ stoichiometry. For the Result of microwaves absorbtion properties using VNA, it obtained the permittivity of BP about 8 between $1.5{\sim}2.5GHz$. In this study, it obtained the BP thin film by deposited in atmosphere pressure And BP thin film can be after to applicate as microwave absolution material is obtained.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.9
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• pp.1174-1184
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• 1997

Extinction characteristics of pure hydrogen-oxygen diffusion flames, at high pressures in the neighborhood of the critical pressure of oxygen, is numerically studied by employing counterflow diffusion flame as a model flame let in turbulent flames in rocket engines. The numerical results show that extinction strain rate increases almost linearly with pressure up to 100 atm, which can be explained by comparison of the chain-branching-reaction rate with the recombination-reaction rate. Since contributions of the chain-branching reactions, two-body reactions, are found to be much greater than those of the recombination reactions, three-body reactions, extinction is controlled by two-body reactions, thereby resulting in the linearity of extinction strain rate to pressure. Therefore, it is found that the chemical kinetic behaviors don't change up to 100 atm. Consideration of the pressure fall-off reactions shows a slight increase in extinction strain rate, but does not modify its linearity to pressure. The reduced kinetic mechanisms, which were verified at low pressures, are found to be still valid at high pressures and show good qualitative agreement in prediction of extinction strain rates. Effect of real gas is negligible on chemical kinetic behaviors of the flames.

• YAKHAK HOEJI
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• v.40 no.6
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• pp.679-683
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• 1996

The current study evaluates the capacity of eugenol to regulate immediate allergic reaction by control of histamine release. Administrations of eugenol (1M/kg, i.p.) at 60 min b efore and 5, 10 min after the compound 48/80 treatment (8mg/kg, i.p.) were shown the mortality rates as 0, 44.4, and 77.8%, respectively. A 60 min before administered group revealed a significant inhibition of serum histamine release compared with those of 5 and 10 min after the compound 48/80 injection. Eugenol (6-48mM) was also showed a dose-dependent activity on the compound 48/80-induced histamine release from the highly purified population of Alcian Blue-positive peritonea] mast cells. These results indicate that in vitro treatment with exogenous eugenol inhibited the active response of mast cell populations and modulated its characteristics.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.97-100
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• 2007

A fluidized bed reactor made of quartz with 0.055 m I.D. and 1.0 m in height was employed for the thermocatalytic decomposition of methane to produce $CO_2$ - free hydrogen . The fluidized bed was proposed for the continuous withdraw of product carbons from the reactor. The methane decomposition rate with the carbon black N330 catalyst was quickly reached a quasi-steady state rate and remained for several hour. The methane and propane mixture decomposition reaction was carried out at the temperature range of 850 - 900 $^{\circ}C$, methane and propane mixture gas velocity of 1.0 $U_{mf}$ ${\sim}$ 3.0 $U_{mf}$ and the operating pressure of 1.0 atm. Effect of operating parameters such as reaction temperature, gas velocity on the reaction rates was investigated. The produced carbon by the methane decomposition was deposited on the surfaces of carbon catalysts and the morphology was observed by TEM image.

• Korean Journal of Veterinary Research
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• v.38 no.3
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• pp.559-564
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• 1998

The polymerase chain reaction(PCR) assay was used for rapid diagnosis from blood and organ samples experimentally infected with Listeria monocytogenes. This method used a pair of primers based on a unique region in the 16S rRNA sequence of L monocytogenes. Procedure A was based on dilution of the blood sample followed by lysis of bacterial cell and direct analysis of the lysate with PCR. In artificially infected blood samples with L monocytogenes, it was possible to detect fewer than 40 cells per ml of blood. However, L monocytogenes was detected low rates on infected organs by the direct PCR. In procedure B, enrichment cultivation was used to increase numbers of bacteria before lysis and PCR. L monocytogenes was detected from 23 samples of 24 liver and spleen, respectively, and 18 samples of 24 blood were found to be positive by PCR on a subset of 72 organ samples, whereas L monocytogenes were detected on 63 organ samples in classical culture technique. It was required to analyze including enrichment steps were 6h and 18h on the procedure A and B, respectively.