• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.19 no.1
• /
• pp.20-30
• /
• 1993

Liquid Chromatographic behavior of Pd(II) in Isonitosoethylacetoacetate imine IEAA-NR: R=H, CH3, C2H5, n-C3H7, n-C4H9, C6H5-CH2) Chelates were investigated by reversed phase high performance 1iquid chromatography on Micropak MCH-5 Column using Methanol /water as mobile phase. The optimum condition for the separation of Pd-Isonitrosoethylacetoacetate imine chelates were examined with respect to the flow rate, mobile phase strength. It was found that Pd(IEAA-NR)2 chelates were eluted in an acceptable range of the capacity factor value (0 $\leq$ log k' $\leq$ 1), The dependence of the logarithm of capacity factor(k') on the volume fraction of water in mixture with in the binary mobile phase was examined. Also, the dependence of k'on the liquid-liquid extraction distribution constant in methanol-water / n-alkane extraction system was on system was invert tigated for Pd(IEAA-NR)2. Both kinds of dependence are linear, which suggests that the retention of the electroneutral metal chelates be largely due to the solvophobic effect.

• Radiation Oncology Journal
• /
• v.24 no.1
• /
• pp.44-50
• /
• 2006

Puroose: This study evaluated the late rectal complications in cervix cancer patients following treatment with external beam radiotherapy (EBRT) and high dose rate intracavitary radiation (HDR ICR). The factors affecting the risk of developing late rectal complications and its incidence were analyzed and discussed. Materials and Methods: The records of 105 patients with cervix cancer who were treated with radical radiotherapy using HDR ICR between July, 1995 and December, 2001 were retrospectively reviewed. The median dose of EBRT was 50.4Gy $(41.4{\sim}56.4 Gy)$ with a daily fraction size of 1.8Gy. A total of $5{\sim}7$ (median: 6) fractions of HDR ICR were given twice weekly with a fraction size of $4{\sim}5 Gy$ (median: 4Gy) to A point using an Ir (Iridium)-192 source. The median dose of ICR was 24 Gy $(20{\sim}35 Gy)$. During HDR ICR, the rectal dose was measured in vivo by a semiconductor dosimeter. The median follow-up period was 32 months, ranging from 5 to 84 months. Results: Of the 105 patients, 12 patients (11%) developed late rectal complications: 7 patients with grade 1 or 2, 4 patients with grade 3 and 1 patient with grade 4. Rectal bleeding was the most frequent chief complaint. The complications usually began to occur $5{\sim}32$ (median: 12) months after the completion of radiotherapy. Multivariate analysis revealed that the measured cumulative rectal BED over 115 Gy3 (Deq over 69 Gy) and the depth (D) of a 5 Gy isodose volume more than 50 mm were the independent predictors for late rectal complications. Conclusion: With evaluating the cumulative rectal BED and the depth of a 5 Gy isodose volume as predictors, we can individualize treatment planning to reduce the probability of late rectal complications.

• Radiation Oncology Journal
• /
• v.18 no.4
• /
• pp.277-282
• /
• 2000

Purpose : Though It has been known that the to tolerance of the liver to external beam irradiation depends on the irradiated volume and dose, few data exist which Quantify this dependence. However, recently, with the development of three dimensional (3-D) treatment planning, have the tools to Quantify the relationships between dose, volume, and normal tissue complications become available. The objective of this study is to investigate the relationships between normal tissue complication probabili쇼 (WCP) and the risk of radiation hepatitis for patients who received variant dose partial liver irradiation. Materials and Methods : From March 1992 to December 1994, 10 patients with hepatoma and 10 patients with bile duct cancer were included in this study. Eighteen patients had normal hepatic function, but 2 patients (prothrombin time 73$\%$, 68$\%$) had mild liver cirrhosis before irradiation. Radiation therapy was delivered with 10MV linear accelerator, 180$\~$200 cGy fraction per day. The total dose ranged from 3,960 cGy to 6,000 cGy (median dose 5,040 cGy). The normal tissue complication probability was calculated by using Lyman's model. Radiation hepatitis was defined as the development of anicteric elevation of alkaline phosphatase of at least two fold and non-malignant ascites in the absence of documented progressive. Results: The calculated NTCP ranged from 0.001 to 0.840 (median 0.05). Three of the 20 patients developed radiation hepatitis. The NTCP of the patients with radiation hepatitis were 0.390, 0.528, 0.844(median : 0.58$\pm$0.23), but that of the patients without radiation hepatitis ranged fro 0.001 to 0.308 (median .0.09$\pm$0.09). When the NTCP was calculated by using the volume factor of 0.32, a radiation hepatitis was observed only in patients with the NTCP value more than 0.39. By contrast, clinical results of evolving radiation hepatitis were not well correlated with NTCP value calculated when the volume factor of 0.69 was applied. On the basis of these observations, the volume factor of 0.32 was more correlated to predict a radiation hepatitis. Conclusion : The risk of radiation hepatitis was increased above the cut-off value. Therefore the NTCP seems to be used for predicting the radiation hepatitis.

• Analytical Science and Technology
• /
• v.5 no.4
• /
• pp.389-399
• /
• 1992

Liquid Chromatographic behavior of Pd(II) in Isonitrosoethylacetoacetate lmine, $Pd(IEAA-NR)_2$ (R=H, $CH_3$, $C_2H_5$, $n-C_3H_7$, $C_6H_5-CH_2$, $n-C_4H_9$) chelates were investigated by reversed-phase HPLC on Micropak MCH-5 column using methanol/water as mobile phase. The optimum conditions for the separation of $Pd(IEAA-NR)_2$ chelates were examined with respect to the effect of the flow rate, sample solvent, mobile phase strength and column temperature. It wass found that metal chelates were properly eluted in an acceptable range of capacity factor value($0{\leq}log\;k^{\prime}{\leq}1$). The dependence of the logarithm of capacity factor(k') on the volume fraction of water in the binary mobile phase was examined. Also, the dependence of k' on the liquid-liquid extration distribution ratio($D_c$) in methanol-water/n-alkane extration system was investigated. Both kinds of dependence are linear, which susggests that the retention of the electroneutral metal chelate is largely due to the solvophobic effect. Standard adsorption enthalpy changes (${\Delta}H^{\circ}$) and standard adsorption entropy changes (${\Delta}S^{\circ}$) of Pd(II) Isonitrosoethylacetoacetate imine chelates on Micropak MCH-5 column were calculated by measuring capacity factor with changing temperature of the column.

• Journal of Advanced Marine Engineering and Technology
• /
• v.29 no.8
• /
• pp.938-945
• /
• 2005

The microstructure evolution in hot forging process is composed of dynamic recrystallization during deformation as well as grain growth during dwell time. Therefore, the control of forging parameters such as strain, strain rate. temperature and holding time is important because the microstructure change in hot working affects the mechanical properties. Modeling equations are developed to represent the flow curve. grain size. recrystallized volume fraction and grain growth phenomena by various tests. The developed modeling equations were combined with thermo-viscoplastic finite element modeling to predict the microstructure change evolution during hot forging process. The large exhaust valve spindle (head diameter of 512mm) was simulated by closed die forging with hydraulic press and cooled in air after forging. The preform was heated to each 1080 and 1150$^{\circ}C$. Numerical calculation was performed by DEFORM-2D. a commercial finite element code. Heat transfer can be coupled with the deformation analysis in a non-isothermal deformation analysis. In order to obtain the fine and homogeneous microstructure and good mechanical properties in forging. the FEM would become a useful tool in the simulation of the microstructure development. In forging, appropriate temperature, strain and strain rate and rapid cooling are required to obtain the fine grain microstructure The optimal forging temperature and effective strain range of Nimonic 80A for large exhaust valve spindle are about 1080$\∼$l120$^{\circ}C$ and 150$\∼$200$\%$.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.20 no.4
• /
• pp.125-132
• /
• 2012

Urea-SCR system, which converts nitrogen oxides to nitrogen and water in the presence of a reducing agent, usually AdBlue urea solution, is known as one of the powerful NOx reduction systems for mobile as well as stationary applications. For its consistent and reliable operation in mobile applications, such various problems as transient injection, ammonia slip, and freezing in cold weather have to be resolved. In this work, therefore, numerical study on three-dimensional unsteady heating problems were analyzed to understand the melting and heat transfer characteristics such as urea liquid volume fraction, temperature profiles and generated natural convection behavior in urea solution by using the commercial software Fluent 6.3. After validating by comparing numerical and experimental data with pure gallium melting phenomena, numerical experiment for urea melting is conducted with three different coolant heating models named CH1, 2, and 3, respectively. Finally, it can be found that the CH3 model, in which more coolant is concentrated on the lower part of the urea tank, has relatively better melting capability than others in terms of urea quantity of $1{\ell}$ for start-up schedule.

• Journal of the Korean Society for Heat Treatment
• /
• v.18 no.2
• /
• pp.99-104
• /
• 2005

In this study, the effects of C and Si on damping capacity and mechanical properties of as-cast and as-rolled Fe-17%Mn alloys were investigated as a basic study for the purpose of the commercialization of the alloy. The $M_s$ temperature of ${\gamma}{\rightarrow}{\varepsilon}$ martensitic transformation in Fe-17%Mn alloy was decreased with increasing C and Si contents, resulting in the less volume fraction of ${\varepsilon}$ martensite. The damping capacity was also decreased with increasing alloying content because of less ${\varepsilon}$ amount and the reduction in mobility of the damping sources such as the stacking fault boundaries and ${\gamma}/{\varepsilon}$ interfaces due to the pinning effect by alloying elements. The mechanical properties of as-rolled alloys were superior to those of as-cast alloys probably because of finer ${\gamma}$ grains, larger amount of ${\varepsilon}$ martensite, and chemical homogeneity.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.35 no.12
• /
• pp.1325-1333
• /
• 2011

An analytical, numerical, and experimental comparison of the hydraulic and thermal performance of new vascular channels with semicircular cross sections was conducted. The following conditions were employed in the study: Reynolds number, 30-2000; cooling channels with a volume fraction of the cooling channels, 0.04; and pressure drop, $30-10^5$ Pa. Three flow configurations were considered: first, second, and third constructal structures with diameters optimized for hydraulic operations. To validate the proposed vascular designs by an analytical approach, 3-D numerical analysis was performed. The numerical model was also validated by the experimental data, and the comparison results were in excellent agreement in all cases. The validation study against the experimental data showed that compared to traditional channels, the optimized structure of the cooling plates could significantly enhance heat transfer and decrease pumping power.

• Journal of the Korea Concrete Institute
• /
• v.26 no.5
• /
• pp.651-660
• /
• 2014

Structural members using ultra high strength concrete which usually used with steel fiber is designed with guidelines based on several investigation of SF-RPC(steel fiber reinforced reactive powder concrete). However, there are not clear design method yet. Especially, SF-RPC member should be casted with steam(90 degree delicious) and members with SF-RPC usually used with precast members. Although the most important design parameter is development method between SF-RPC and steel reinforcement(rebar), there are no clear design method in the SF-RPC member design guidelines. There are many controversial problems on safety and economy. Therefore, in order to make design more optimum safe design, in this study, we investigated bond stress between steel rebar and SF-RPC according to test. Test results were compared with previously suggested analysis method. Test was carried out with direct pull out test using variables of compressive strength of concrete, concrete cover and inclusion ratio of steel fiber. According to test results, bond stress between steel rebar and SF-RPC increased with increase of compressive strength of concrete and concrete cover. Increasing rate of bond stress were decrease with increase of compressive strength of SF-RPC and concrete cover significantly. 1% volume fraction inclusion of steel fiber increase the bond stress between steel rebar and SF-RPC with two times but 2% volume fraction cannot affect the bond stress significantly. There are no exact or empirical equations for evaluation of SF-RPC bond stress. In order to make safe bond design of SF-RPC precast members, previously suggested analysis method for bond stress by Tepfers were evaluated. This method have shown good agreement with test results, especially for steel fiber reinforced RPC.

• The Journal of Korean Society for Radiation Therapy
• /
• v.21 no.1
• /
• pp.25-31
• /
• 2009

Purpose: Evaluate the mold we have made to improve the reproducibility of the patient position and make homogeneous dose distribution to the treatment volume effectively when treating the patient who has hypervascular ulcer on her tongue caused by paraneoplastic autoimmune multiorgan syndrome by mold brachytherapy. Materials and Methods: The mold is consisted of upper and lower parts. We inserted 2 mm of lead sheet on the gums toward the oral cavity to protect them from unnecessary irradiation during the treatment. We had planned on orthogonal images obtained the patient. 200 cGy was delivered in every fraction with a total dose of 3000 cGy. To evaluate the effect of the lead sheet, we made a measurement with a phantom that has gums and tongue made of tissue with an equivalent material (bolus). Five of TLDs were placed on the interesting points of gums to measure the dose during irradiation with lead sheet and without lead sheet for three times respectively. Results: The result of the measurement without lead sheet are A: 33.9 cGy, B: 30.1 cGy, C: 31.8 cGy, D: 23.3 cGy, E: 24.1 cGy. The results of measurement with lead sheet are A: 20.6 cGy, B: 18.8 cGy, C: 19.6 cGy, D: 14.7 cGy, E: 15.1 cGy. Conclusion: Since we are using the mold made in our department during the treatment of the patient with hypervascular ulcer on tongue, we could deliver a proper dose to the treatment volume. In addition, the mold provided highly accurate and reproducible treatment and reduced the dose to the gums and teeth. Therefore, the possibility of side effects could be decreased significantly.