• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.3
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• pp.1028-1039
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• 1996

This study was focused on the examination of the flame structure and the combustion characteristics of diffusion flame which was formed the turbulent shear flow of a double coaxial air jet system. The shear flow was formed by the difference velocity of surrounding air jet(U$\_$s/) and center air jet (U$\_$c/). So experimental condition was divided S-type flame (.lambda. > 1) and C-type flame (.lambda. < 1) by velocity ratio .lambda. (=U$\_$s//U$\_$c/). For examination of the flame structure and the combustion characteristics in diffusion flame, coherent structure was observed in flame by schlieren photograph method. We measured fluctuating temperature and ion current simultaneously and accomplished the statistical analysis of its. According to schlieren photograph, the flame was stabilized in the rim of the direction of lower velocity air jet, coherent eddy was produced and developed by higher velocity air jet. The statistical data of fluctuating temperature and ion current was indicated that reaction was dominated by higher velocity air jet. The mixing state of burnt gas and non-burnt gas was distributed the wide area at Z = 100 mm of C-type flame.

• Parasites, Hosts and Diseases
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• v.46 no.3
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• pp.179-182
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• 2008

As a part of a broader effort to determine the status of Paragonimus species infection in Lao PDR, an epidemiological survey was conducted on villagers and schoolchildren in Namback District between 2003 and 2005. Among 308 villagers and 633 primary and secondary schoolchildren, 156 villagers and 92 children evidenced a positive reaction on a Paragonimus skin test. Only 4 schoolchildren out of 128 skin test-positive cases had Paragonimus sp. eggs in their sputum, all of which was collected on 1 day. Several types of crabs, which were identified as the second intermediate host of the Paragonimus species, were collected from markets and streams in a paragonimiasis endemic area for the inspection of metacercariae. Among the examined crabs, only "rock crabs" (Indochinamon au) harbored Paragonimus sp. metacercariae, and it is speculated that the life cycle of Paragonimus sp. was maintained via rock crabs in Namback District, Lao PDR.

• Journal of Electrochemical Science and Technology
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• v.14 no.3
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• pp.272-282
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• 2023

Ni-rich layered oxides cathode has recently gained attention as an advanced cathode material due to their applicable energy density. However, as the Ni component in the layered site is increased, the high reactivity of Ni⁴⁺ results in parasitic reaction associated with decomposing electrolyte, which leads to a rapid decreasing the lifespan of the cell. The electrolyte additive triallyl borate (TAB) improves interfacial stability, leading to a stable cathode-electrolyte interphase (CEI) layer on the LNCM83 cathode. A multi-functionalized TAB additive can produce a uniformly distributed CEI layer via electrochemical oxidation, which implies an increase in long-term cycling performance. After 100 cycles at elevated temperature, the cell tested by 0.75 TAB retained 88.3% of its retention ratio, whereas the cell performed by TAB-free electrolyte retained 64.1% of its retention. Once the TAB additive formed CEI layers on the LNCM83 cathode, it inhibited the decomposition of carbonate-based solvents species in addition to the dissolution of transition metal components from the cathode. The addition of TAB to LNCM83 cathode material is believed to be a promising way to increase the electrochemical performance.

• Applied Chemistry for Engineering
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• v.10 no.5
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• pp.767-771
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• 1999

Poly(ester-imide)(PEI) for the electrical insulation coating was synthesized and evaluated with one-step method as well as two-step method. For the synthesis of poly(ester-imide), imide repeat unit of N,N'-(4,4'-diphenylmethane) bistrimellitimide(DID) was initially made from trimellitic anhydride(TMA) and methylene dianiline(MDA), followed by the second stage reaction of esterification. One-step reaction was performed by reaction of TMA, MDA, dimethyl terephthalate(DMT), ethylene glycol(EG), and 1,3,5-tris-(2-hydroxy ethyl) isocyanurate(THEIC) in m-cresol solvent at a time. The synthesized poly(ester-imide) was cured with xylene, P-5030K(phenol-formaldehyde resin), TK-8(TDI type blocked polyisocyanate) and tetrapropyltitanate(TPT). It was found that the content of hydroxyl group, amount of DMT, and imide repeat unit played important role for the properties of electrical insulation coating film.

• Applied Chemistry for Engineering
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• v.10 no.6
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• pp.843-847
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• 1999

In this research, C/SiC composites, i.e. activated carbon coated with SiC obtained from dichlorodimethylsilane(DDS) and hydrogen, have been made by chemical vapor infiltration(CVI) in a fluidized bed reactor. Activated carbons of sizes of 4~12, 12~20, and 20~40 mesh were used. After deposition the surface area, the amount and the shape of deposit of each sample were observed at different concentrations of reactant DDS, sizes of activated carbon, reaction pressures and reaction times. The experimental results showed that uniform deposition in the pores of sample was obtained at a lower concentration of DDS and a lower pressure. Additionally, from the observation that the pore diameter and the surface area have minimum values at a certain time of deposition, it was known that deposition occurred inside of the pore at first and then on the outside of particle. Small particles of SiC were deposited uniformly on the surface of activated carbon at lower DDS concentrations and lower reaction pressures. The results were confirmed by SEM, TGA, the pore size distribution analyzer and BET.

• Korean Chemical Engineering Research
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• v.51 no.5
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• pp.531-535
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• 2013

The effect of heat-treatment temperature on the activity of catalysts was studied by investigating $N_2O$ decomposition reaction in Fe ion-supported BEA Zeolite. As a result of $N_2O$ decomposition reaction experiment, $N_2O$ decomposition activity significantly decreased as heat-treatment temperature of Fe/BEA catalyst increased. the shape and size of the particles of Fe/BEA catalyst following the rise of heat-treatment temperature did not display a significant change. But following the rise of the heat-treatment temperature, its surface area was significantly reduced. Also it was confirmed that as the heat-treatment temperature rose, the crystallization of ${\beta}$ structure was greatly reduced. And as heat-treatment temperature rose, while SiO structure either increased or did not exhibit much change, the structure of Fe bonded with lattice structure was speculated to decrease. From the stated results, it was concluded that the increase of heat-treatment temperature became the cause of the declined activity of catalysts by destruction of its ${\beta}$ structure of bonding aluminium and Fe atoms.

• Journal of agricultural medicine and community health
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• v.13 no.1
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• pp.41-59
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• 1988

In many of the helminthic infections, diagnosis is accomplished by the demonstration of the eggs or, occasionally the adult worms or their parts. Diagnosis can be made by the identification of larval stage obtained from stool or surgically extracted materials too. However some kinds of parasitic disease can not be diagnosed by above mentioned procedure alone. Brain cysticercosis, ectopic paragonimiasis, Capillaria hepatica infection in liver is a good example. In such a case, immunologic method would be helpful for the decision of physician. In this paper, immunologic tools such as indirect hemagglutination test, indirect fluorescent antibody test, circumoval precipitation test, ELISA, western blot were applied for the diagnosis of Clonorchis sinenisis, Cysticercosis and C. hepatica a infection and their efficacy was evaluated. The results obtained were as follows ; 1) In the diagnosis of clonorchiasis, ELISA revealed sensitiveity of 83.3%, but cross reaction against antibody of Paragonimus westermani and Taenia species were observed. For the identification of cross reaction and species specific band of Ag-Ab reaction, western blot was applied. 59Kd relative molecular weight and 21Kd band were identified as a Clonorchis sinensis specific band. OD values of ELISA performed with sera of 18 months after praziquantel treatment decreased to half level compared to that of before treatment. Negative conversion rate of ELISA after 18 months of treatment was 60%. 2) In the diagnosis of cysticercosis, IFAT disclosed 95.8%(23/24) of sensitivity and reaction was most strongly occurred in inner membrane. ELISA revealed 90.0% (36/40) of sensitivity, but cross reaction was observed in both technique. In western blot, 91, 63 and 21Kd Mw bands were identified as a strongly positive band. Among them 63Kd band showed positive reaction against almost all sera of cysticercosis patient. 3) Circumoval precipitation, ELISA, IFAT, showed 85.0% of sensitivity in the diagnosis of C. hepatica infection in rat. The antigenic localities were inner membrane of sectioned egg antigen on the prectipitates around the mucoid plugs which were induced by circumoval precipitation reaction. Sera from rats infected with 2000eggs were collected periodically to observe the changing patterns of antibody titers by IFAT and ELISA, which showed that high titers were detected at weeks 3 and 5, then gradually declined through weeks 9until to negatively converted at weeks 13.

• The Journal of the Petrological Society of Korea
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• v.21 no.3
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• pp.309-333
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• 2012

Basalt having lots of feldspar phenocryst occurred at the northern and southern slope of the Mt. Halla, Jejudo. Among them, the Sioreum trachybasalt in southern slope consists of abundant phenocrysts of plagioclase in aphanitic groundmass. And the number of plagioclase grains are about 20 per $10cm^2$, and based on 667 grains the sizes are 13~0.7 mm (average 4.23 mm) in length and 8.6~0.5 mm (average 2.3 mm) in width. In according to modal analyses, Sioreum basaltic rock consists mainly of plagioclase (16~28%), olivine, clinopyroxene (1.5~6%) and opaque minerals (~0.1%) of magnetite and ilmenite as phenocryst and microphenocryst and groundmass (60~82%). The compositions of plagioclase, olivine and clinopyroxene are bytownite~andesine, chrysolite~hyalosiderite, augite respectively. Plagioclase phenocrysts show different type of zoning, namely, normal, reversal, patchy, oscillatory type. The An contents of zoned plagioclase mainly increase from core to rim. Those of oscillatory type from core to rim show variations of increase following decrease or decrease following increase, being more enriched in rim or almost same to core. Under the microscope, some plagioclase phenocrysts are especially melted in core part or marginal part, or found as only the remnant remain which resulted from reaction with melt. Some clinopyroxene are also corroded in margin part or found as irregular shape resulted from melting. The characteristics of petrography and compositional variation from core to rim of plagioclase and clinopyroxene, indicate that they are disequilibrium with melt and has been undergone geological environmental changes in magma batch during crystallization including magma mixing with replenishment of more mafic and high temperature melt.

• The Korean Journal of Applied Statistics
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• v.35 no.2
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• pp.251-263
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• 2022

Phase I clinical trial is called 'Dose finding study'. It is first step of experimenting on humans with new drugs developed through animal experiments or vitro experiments. The important area of interest in designing Phase I clinical trial is determining the dose that acceptable level to the patients and provides the greatest efficacy. In this paper, we explain about methods to determine the maximum tolerated dose using various stopping rules. The SM3, NM, Rim, J3, BSM methods are compared through simulation. And we consider how the methods might be reformed. As a result of the simulation, BSM estimated the MTD closest to the target toxicity probability. J3 method required the least number of subjects. These results are due to the feature of the stopping rules of both methods. The BSM adds 2 or 1 subject at the same dose level when there is a toxic reaction. In addition, the J3 method has a smaller number of subjects than the other methods. If the methods are improved by combining these features, MTD can be estimated more efficiently. If the total number of subjects can be reduced while using the stopping rule of the BSM, accurate estimation is possible for a small number of subjects.

• Journal of Korean Neurosurgical Society
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• v.57 no.4
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• pp.307-310
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• 2015

We report a case of a paradoxical response of a tuberculoma in the brain mimicking a brain tumor. A 76-year-old woman presented with a 2 week history of headache, dysarthia, and orthopnea. Brain magnetic resonance images (MRI) revealed two rim-enhancing lesions on the pons and occipital lobe, and chest computed tomography showed randomly distributed miliary nodules. The tentative diagnosis was tuberculosis (TB) of the brain and lung. She complained of right hemiparesis and worsening general weakness after taking the anti-TB medication. On the monthly follow-up images, the enhanced lesions were enlarged with increased perfusion and choline/creatinine ratio, suggesting a high grade glioma. A surgical resection was completed to diagnose the occipital lesion, and the tuberculoma was pathologically confirmed by a positive TB-polymerase chain reaction. The anti-TB medication was continued for 13 months. A follow-up MRI showed decreased size of the brain lesions associated with perilesional edema, and the clinical symptoms had improved. Brain tuberculoma could be aggravated mimicking brain malignancy during administration of anti-TB medication. This paradoxical response can be effectively managed by continuing the anti-TB drugs.