• The Korean Journal of Cytopathology
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• v.12 no.1
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• pp.67-71
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• 2001

Primary malignant lymphoma of the thyroid gland is uncommon malignancies. Its fine needle aspiration cytology (FNAC) findings are rarely described in the literature. This article highlights the FNAC diagnosis of primary malignant lymphoma of the thyroid gland. A 70-year-old female presented with a rapidly enlarging thyroid mass of five months' duration. FNAC smears showed low cellularity consisting of predominantly atypical enlarged lymphoid cells admixed with a few small lymphocytes, plasma cells, and oncocytic cells. Some disrupted lymphoid cells were also present. The tumor cells infiltrated into the thyroid follicular epithelium forming lymphoepithelial lesion, The cytologic appearance showed a diffuse mixture of cell types with only a few small, mature lymphocytes and many enlaraed lymphoid cells. The enlarged lymphoid cells were atypical and pleomorphic with nuclear clefting and irregularities. Grossly, the left lobe of the thyroid was nearly replaced by a diffuse firm to soft solid mass with smooth tan fish-flesh homogeneous cut surface. Histological diagnosis was diffuse large B-cell lymphoma with areas of marginal zone B-cell lymphoma of MALT type.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1341-1346
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• 2004

Detailed flame structures of the opposed flames formed for different oxidant compositions are studied numerically. The detailed chemical reactions are modeled by using the CHEMKIN code. Only the $CO_{2}$ and $H_{2}O$ are assumed to participate by absorbing the radiative energy while all other gases are assumed to be transparent. The discrete ordinates method and a narrow band based WSGGM with a gray gas regrouping technique are applied for modeling the radiative transfer through non-homogeneous and non-isothermal combustion gas mixtures generated by the opposed flow flames. The results show that the different radiation model can cause different results for flame structures and the WSGGM with gray gas regrouping is successful in modeling the opposed flames with non-gray gas mixture. The results also show that a reasonable information on the flame structure can be obtained from the modeling by considering different chemical compositions of the oxidant.

• Journal of Energy Engineering
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• v.8 no.2
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• pp.333-340
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• 1999

A numerical study of turbulent condensing vapor jet submerged in subcooled liquids has been conducted. A physical model of the process is presented employing the locally homogeneous flow approximation of two phase flow in conjunction with a $\kappa$-$\varepsilon$-g model of turbulence properties. In this model the turbulence is represented by differential equations for its kinetic energy and dissipation. A differential equation for the concentration fluctuations is solved and a clipped normal probability distribution function is proposed for the mixture fraction. Effects of steam mass flux, pool temperature and nozzle internal diameter on the condensing vapor jet are also analyzed. The model is evaluated using existing data for turbulent condensing vapor jets. The agreement between the predictions and the available experimental data is good.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.4
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• pp.83-88
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• 2013

Recently, PCCI (premixed charge compression ignition) combustion is studied to reduce both NOx and PM because of homogeneous mixture formation and lower combustion temperature. It has also merit of increasing thermal efficiency owing to better air-fuel mixure. However, it is well known that PCCI combustion has a weakness in fuel economy because PCCI combustion tends to start before TDC. Therefore, it is necessary to find an optimal conditions for PCCI combustion which maintains reduction of NOx, PM and increase of thermal efficiency. In this study, pPCCI combustion was realized by adding early injection strategy to a conventional diesel engine. In addition, the characteristics of pPCCI combustion was analized by comparing conventional diesel injection strategy. The results show that NOx and PM per power in pPCCI combution were reduced compared to a conventional diesel combustion.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.5
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• pp.89-95
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• 2001

Recently GDI(Gasoline Direct Injection) engine is spotlighted to achieve higher thermal efficiency under partial loads and better performance at full loads. To realize this system, it is essential to make both stratified combustion and homogeneous combustion. When compared to PFI(Port Fuel Injection) engine, GDI engine needs more complicated control and optimal design with injection system. In addition, spray pattern must be optimized according to injection timing because ambient pressure in combustion chamber is also varied. Thus spray structure should be analyzed in details to meet various conditions. In this experimental study, two types of visualization system were developed to simulate compression stroke and intake stroke, respectively. With an increase of the ambient pressure, the penetration length tends to decrease due to rising resistance caused by the drag force of the ambient air. Spray characteristics impinged on the piston has a significant effect on mixture stratification around the spark plug. These results provide the information on macroscopic spray structure and design factors far developing GDI injector.

• Korean Journal of Materials Research
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• v.11 no.11
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• pp.986-990
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• 2001

An optimum route to fabricate the $A1_2O_3/Fe-Ni$ alloy nanocomposites with sound microstructure and enhanced mechanical properties as well as magnetism was investigated. To prepare homogeneous nanocomposite powders of Fe-Ni alloy and $Al_2O_3$, the solution-chemistry routes using $Al_2O_3 \; Ni(NO_3)_2{\cdot}6H_2O$ and $Fe(NO_3)_3{\cdot}9H_2O$ powders were applied. Microstructural observation of the powder mixture revealed that the Fe-Ni alloy particles of about 20 nm in size were homogeneously surrounded $A1_2O_3$, forming nanocomposite powder. The hot-pressed composite showed improved fracture toughness and magnetic response. These results suggest that the synergy materials with an improved mechanical properties and excellent functionality can be fabricated by controlled powder preparation and consolidation processing.

• Journal of the Korean Society of Combustion
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• v.10 no.3
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• pp.10-16
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• 2005

Detailed flame structures of the counterflow flames of $CH_4/Air$ formed with $CO_2$ and $H_2O$ addition are studied numerically. The detailed chemical reactions are modeled by using the OPPDIF and CHEMKIN-II code. Only the $CO_2$ and $H_2O$ are assumed to participate in radiative heat transfer while all other gases are assumed to be transparent. The discrete ordinates method(DOM) and the narrow band based WSGGM with a gray gas regrouping technique(WSGGM-RG) are applied for modeling the radiative transfer through non-homogeneous and non-isothermal combustion gas mixtures generated by the counter flow flames. The results compared with the SNB model show that the WSGGM-RG is successful in modeling the counterflow flames with non-gray gas mixture. The numerical results show that the addition of $CO_2$ and $H_2O$ to the oxidant nozzle lowers the peak temperature and the NO concentration in flame.

• Journal of Microbiology and Biotechnology
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• v.8 no.6
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• pp.631-638
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• 1998

Studies were made to elucidate the cell growth and the production of camptothecin and its derivatives in cell cultures of Camptotheca acuminata. High resolution HPLC chromatograms to analyze camptothecin and 10-hydroxycamptothecin in lactone and carboxylate forms were obtained with a fluorescence detector. Calli inductions were optimized with the young stem of explant on Schenk and Hildebrandt (SH) medium supplemented with 5 mg/l $\alpha$-naphthaleneacetic acid (NAA), 0.2 mg/l 6-benzylamino purine (BAP), 2.0% sucrose, and 0.5% agar. The hybrid medium, a mixture of SH and Murashige and Skoog (MS) salts, was developed for homogeneous suspension cultures without large cell aggregates. The optimum phytohormone concentrations for successful suspension cultures were 1.0mg/l of 2,4-D and 0.5 mg/l of kinetin. The highest growth in suspension cultures was observed when 49.7% (w/w) of the cells was composed of small aggregates which were below 0.1 mm in diameter. Time course changes of cell growth and camptothecin production showed that camptothecin accumulation was started at the end of the growth phase and the maximum content was obtained 10 days after inoculation. Yeast extract elicitor increased camptothecin accumulation 4 times. Methyl jasmonate and jasmonic acid also increased camptothecin production 6 and 11 times, respectively.

• Journal of Pharmaceutical Investigation
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• v.38 no.5
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• pp.289-293
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• 2008

To develop a poloxamer-based solid suppository with poloxamer and polyethylene glycol mixtures, the melting point of various formulations composed of P 188 and propylene glycol were investigated. The dissolution and antitumor activity of clotrimazole delivered by the poloxamer-based suppository were performed. The poloxamer mixtures composed of P 188 and propylene glycol were homogeneous phases. P 188 greatly affected the melting point of poloxamer mixtures. In particular, the poloxamer mixture [P 188/propylene glycol(70/30%)] with the melting point of about $32^{\circ}C$ was a solid form at room temperature and instantly melted at physiological temperature. Furthermore, the ratio of P 188/propylene glycol greatly affected the dissolution rates of clotrimazole from poloxamer-based suppository. It gave the more effective anti-tumor activity than conventional PEG-based suppository due to fast dissolution. Thus, the clotrimazole-Ioaded poloxamer-based solid suppository was an effective rectal dosage form with anti-tumor activity.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.3
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• pp.43-49
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• 2013

This work investigated the effects of engine speed and injection timing on combustion and emissions characteristics in a partially premixed charge compression ignition (pPCCI) engine fueled with DME. pPCCI engine especially has potential to achieve more homogeneous mixture in the cylinder, which results in lower NOx and smoke emission. In this study single cylinder engine was equipped with common rail and injection pressure is 700 bar. Total injected fuel mass is 64.5 $mm^3$ per cycle. The amount of pilot injection of the entire injection 12.5% is tested. Results show that NOx emission is decreased while IMEP is increased as the retard of injection timing. Besides, NOx emissions are slightly rised as well as IMEP is increased with the increase of engine speed.