• Membrane Journal
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• v.30 no.5
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• pp.307-318
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• 2020

Conventional perfluorinated sulfonic acid membrane, Nafion is widely used for vanadium redox flow battery (VRFB). It is desired to prevent vanadium ion permeation through a membrane to retain the capacity, and to keep the cell efficiency of a VRFB. Highly proton conductive and chemically stable Nafion membranes, however, suffer from high vanadium permeation, which induce the reduction in charge and discharge capacity by side reactions of vanadium ions. In this study, to resolve the issue, silica nanoparticles, which are functionalized with 3-aminopropyl group (fS) are introduced to enhance the long-term performance of a VRFB by lowering vanadium permeation. It is expected that amine groups on silica nanoparticles are converted to positive ammonium ion, which could deteriorate positively charged vanadium ions' crossover by Gibbs-Donnan effect. There is reduction in proton conductivity may due to acid-base complexation between fS and Nafion side chains, but ion selectivity of proton to vanadium ion is enhanced by introducing fS to Nafion membranes. With the composite membranes of Nafion and fS, VRFBs maintain their discharge capacity up to 80% at a high current density of 150 mA/㎠ during 200 cycles.

• Korean Chemical Engineering Research
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• v.47 no.3
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• pp.362-367
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• 2009

Recently, the use of formic acid as a fuel for direct liquid fuel cells has emerged as a promising alternative to methanol. In the work presented herein, we evaluated direct formic acid fuel cells(DFAFCs) with various components under operating conditions, for example, the thickness of the proton exchange membrane, concentration of formic acid, gas diffusion layer, and commercial catalyst. The thickness of the proton exchange membrane influenced performance related to the fuel cross-over. To optimize the cell performance, we investigated on the proper concentration of formic acid and catalyst for the formic acid oxidation. Consequently, membrance-electrode assembly(MEA) consisted of $Nafion^{(R)}$-115 and the Pt-Ru black as a anode catalyst showed the maximum performance. This performance was superior to the DMFCs' one.

• Smart Media Journal
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• v.9 no.3
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• pp.31-40
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• 2020

Currently, black-box-based machine learning algorithms are used to analyze big data in manufacturing. This algorithm has the advantage of having high analytical consistency, but has the disadvantage that it is difficult to interpret the analysis results. However, in the manufacturing industry, it is important to verify the basis of the results and the validity of deriving the analysis algorithms through analysis based on the manufacturing process principle. To overcome the limitation of explanatory power as a result of this machine learning algorithm, we propose a manufacturing big data analysis method using genetic programming. This algorithm is one of well-known evolutionary algorithms, which repeats evolutionary operators such as selection, crossover, mutation that mimic biological evolution to find the optimal solution. Then, the solution is expressed as a relationship between variables using mathematical symbols, and the solution with the highest explanatory power is finally selected. Through this, input and output variable relations are derived to formulate the results, so it is possible to interpret the intuitive manufacturing mechanism, and it is also possible to derive manufacturing principles that cannot be interpreted based on the relationship between variables represented by formulas. The proposed technique showed equal or superior performance as a result of comparing and analyzing performance with a typical machine learning algorithm. In the future, the possibility of using various manufacturing fields was verified through the technique.

• Cartoon and Animation Studies
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• s.32
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• pp.23-42
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• 2013

The music videos of and were made based on the music of Pink Floyd and Beatles. This study aims to compare the characteristics of the two songs in terms of music and storytelling method. Previous studies investigated the narrative structure and concept of the storytelling, which are the basis of the images. This study, a comparative study of the two songs, firstly analyzed the narrative structure focusing on the roles and relationships among characters in each song. Secondly, it investigated the method of composition structure and the characteristics of the two pieces of music of which genre is different from each other. Thirdly, it classified the images into intro part, development part, and conclusion part and analyzed by comparison how the song or images inserted in the music interacts with each other. As a result, it was found that described strong progressive rock from the subjective viewpoint through the material storytelling structure by space and it represents the alienation of the hero through simile and metaphor, spatial changes crossing the past and the present, and the actual and non-actual crossover directing. On the other hand, developed a narrative storytelling structure in which progressive fantasy images developed from the psychedelic viewpoint through the confrontation of the good and the bad to deliver the messages of love and peace.

• Journal of Veterinary Clinics
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• v.19 no.2
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• pp.186-190
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• 2002

This crossover study was performed in order to compare the effects of cetirizine, loratadine, and terfenadine in canine skin. Five healthy dogs were used. Cetirizine 0.5 mg/kg, loratadine 5 mg/kg and terfenadine 5 mg/kg were administered orally 4 hours before the experiment. Erythema indices and wheal size were assessed by Hexameter ($MX^{\circledR}$ 18, CK, Germany) and skin reaction guide, respectively. Cetirizine-induced erythema inhibition was generally higher than other drugs and was significantly different from placebo. Cetirizine was superior to placebo at 3, 4, 5, 6, 7, and 8 minutes (p< 0.01). Cetirizine also was superior to placebo at 9 minutes (p< 0.05). Loratadine and terfenadine erythema inhibition were better than after placebo treatment from 4 to 9 minutes, but erythema index of terfenadine at 7 minutes was not observed probability of 95% and 99%. At 10 minutes, intradermal injection of the histamine caused a mean wheal dimension for placebo, cetirizine, loratadine and terfenadine, which were 13.25$\pm$0.75 mm,7.5$\pm$ 1.02 mm (53% reduction, p<0.007),6.2$\pm$0.58 mm(43% reduction, p <0.01), and 8.4 $\pm$0.67 mm(37% reduction, p< 0.05), respectively, comparing with placebo. Loratadine and cetirizine were good antihistamines for clinical therapy for atopic dermatitis in dog.

• Journal of Preventive Medicine and Public Health
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• v.42 no.3
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• pp.165-170
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• 2009

Objectives : We evaluated the risk of fracture associated with hypotension-related adverse drug reaction caused by taking alpha blockers to treat benign prostatic hyperplasia (BPH). Methods : We used the Health Insurance Review and Assessment Service database from January 1st 2005 to June 30th 2006 for this study. The male patients with BPH and who had a prescription for alpha blockers following any fractures were defined as the cases. We set the 20 day long hazard period prior to the index date and the four control periods whose lengths were same with hazard period. After 1:4 matching of the hazard and control periods, conditional logistic regression was used to calculate the odds ratios for the risk of fractures as related to the alpha blocker exposure. Results : Doxazosin and tamsulosin showed the increased risk of fractures, whereas terazosin did not. After stratification using the defined daily doses, a protective effect was shown for the patients who took terazosin at the doses lower than 0.4 DDD and the hazardous effect at the doses higher than or equal to 0.4 DDD. There was no significant difference for the risk of patients taking tamsulosin at the doses higher than 1.0 DDD but there was a statistically significant increase in the risk at the doses higher than or equal to 1.0 DDD. Conclusions : Alpha blockers for BPH may increase the risk of fracture in elderly patients who have comorbidities and take the concomitant medications. Alpha blockers need to be prescribed with caution, although some have high prostate specificity.

• Biomolecules & Therapeutics
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• v.9 no.4
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• pp.291-297
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• 2001

The bioequivalence of two triflusal products was evaluated with 20 healthy volunteers following single oral dose according to the guidelines of Korea Food and Drug Administration (KFDA). Trisa $l^{R}$ capsule (Whanin Pharm. Corp., Korea) and Disgre $n^{R}$ capsule (Myung-In Pharm. Corp., Korea) were used as test product and reference product, respectively. Both products contain 300 mg of trifusal. One capsule of test product or reference product was orally administered to the volunteers, respectively, by randomized two period crossover study (2$\times$2 Latin square method). Blood samples were taken at predetermined time intervals for 4 hours and the determination of trifusal was accomplished using semi-microbore HPLC equipped with automated column switching system. The analytical method with HPLC was validated according to the Bioanalytic Method Validation guideline by F7A prior to determining the plasma samples. The pharmacokinetic parameters (AU $C_{0-4h}$ $C_{max}$ and $T_{max}$) were calculated and ANOVA test was utilized for statistical analysis of parameters. As a result of the assay validation, the limit of quantification of trifusal in human plasma by current assay procedure was 50 ng/ml using 500 $\mu$l of plasma. The accuracy of the assay was from 97.76% to 116.51% while the intra-day and inter-day coefficient of variation of the same concentration range was less than 15%. Average drug concentration at the designated time intervals and pharmacokinetic parameters calculated were not significantly different between two products (p>0.05). The difference of mean AU $C_{olongrightarrow4hr}$, $C_{max}$, and $T_{max}$ between the two products (2.92, 4.39, and -2.44%, respectively) were less than 20%. The power (1-$\beta$) and treatment difference ($\Delta$) for AU $C_{olongrightarrow4hr}$ and $C_{max}$ were more than 0.8 and less than 0.2, respectively. Although the power for $T_{max}$ was under 0.8, $T_{max}$ of the two products was not significantly different from each other (p>0.05). These results satisfied the criteria of KFDA guideline for bioequivalence, indicating the two products of triflusal were bioequivalent.quivalent.ent.ent.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.407-408
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• 2011

Natural boron consists of two stable isotopes 10B and 11B with natural abundance of 18.8 atom percent of 10B and 81.2 atom percent of 11B. The thermal neutron absorption cross-section for 10B and 11B are 3837 barn and 0.005 barn respectively. 10B enriched specific compounds are used for control rods and as a reactor coolant additives. In this work 2 methods for boron enrichment were analysed: 1) Gas irradiation in static conditions. Dissociation occurs due to multiphoton absorption by specific isotopes in appropriately tuned laser field. IR shifted laser pulses are usually used in combination with increasing the laser intensity also improves selectivity up to some degree. In order to prevent recombination of dissociated molecules BCl3 is mixed with H2S 2) SILARC method. Advantages of this method: a) Gas cooling is helpful to split and shrink boron isotopes absorption bands. In order to achieve better selectivity BCl3 gas has to be substantially rarefied (~0.01%-5%) in mixture with carrier gas. b) Laser intensity is lower than in the first method. Some preliminary calculations of dissociation and recombination with carrier gas molecules energetics for both methods will be demonstrated Boron separation in SILARC method can be represented as multistage process: 1) Mixture of BCl3 with carrier gas is putted in reservoir 2) Gas overcooling due to expansion through Laval nozzle 3) IR multiphoton absorption by gas irradiated by specifically tuned laser field with subsequent gradual gas condensation in outlet chamber It is planned to develop software which includes these stages. This software will rely on the following available software based on quantum molecular dynamics in external quantized field: 1) WavePacket: Each particle is treated semiclassicaly based on Wigner transform method 2) Turbomole: It is based on local density methods like density of functional methods (DFT) and its improvement- coupled clusters approach (CC) to take into account quantum correlation. These models will be used to extract information concerning kinetic coefficients, and their dependence on applied external field. Information on radiative corrections to equation of state induced by laser field which take into account possible phase transition (or crossover?) can be also revealed. This mixed phase equation of state with quantum corrections will be further used in hydrodynamical simulations. Moreover results of these hydrodynamical simulations can be compared with results of CFD calculations. The first reasonable question to ask before starting the CFD simulations is whether turbulent effects are significant or not, and how to model turbulence? The questions of laser beam parameters and outlet chamber geometry which are most optimal to make all gas volume irradiated is also discussed. Relationship between enrichment factor and stagnation pressure and temperature based on experimental data is also reported.

• Journal of Pharmaceutical Investigation
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• v.28 no.4
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• pp.283-288
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• 1998

Lovastatin, one of the potent cholesterol-lowering agents, is an inactive lactone prodrug which is metabolized to its active open acid, lovastatin acid (LVA). Bioequivalence study of two lovastatin preparations, the test drug ($Mevacor^{\circledR}$: Chungwae Pharmaceutical Co., Ltd.) and the reference drug ($Lovaload^{\circledR}$: Chong Kun Dang Pharmaceutical Co., Ltd.), was conducted according to the guidelines of Korea Food and Drug Administration (KFDA). Fourteen healthy male volunteers, $23.9{\pm}3.9$ years old and $67.6{\pm}8.0$ kg of body weight in average, were divided randomly into two groups and administered the drug orally at the dose of 160 mg as lovastatin in a $2{\times}2$ crossover study. Plasma concentrations of lovastatin acid were analysed by HPLC method for 12 hr after administration. The extent of bioavailability was obtained from the plasma concentration-time profiles of total lovastatin acid after alkaline hydrolysis of the plasma samples. By alkaline hydrolysis, trace amounts of unmetabolized lovastatin were converted to lovastatin acid. The $AUC_{0-12hr}$ was calculated by the linear trapezoidal rule method. The $C_{max}$ and $T_{max}$ were compiled directly from the plasma drug concentration-time data. Student's t-test indicated no significant differences between the formulations in these parameters. Analysis of variance (ANOVA) revealed that there were no differences in AUC, $C_{max}$, and $T_{max}$ between the formulations. The apparent differences between the formulations were far less than 20% (e.g., 7.07, 5.77 and 1.18% for AUC, $C_{max}$, and $T_{max}$, respectively). Minimum detectable differences(%) between the formulations at ${\alpha}=0.05$ and $1-{\beta}=0.8$ were less than 20% (e.g., 17.2, 15.1, and 15.9% for AUC, Cmax, and Tmax, respectively). The 90% confidence intervals for these parameters were also within ${\pm}20%$ (e.g.. $-5.20{\sim}19.3$, $-5.00{\sim}16.5$, and $-10.2{\sim}12.5%$ for AUC, $C_{max}$, and $T_{max}$, respectively). These results satisfied the bioequivalence criteria of KFDA guidelines, indicating that the two formulations of lovastatin were bioequivalent.

• Journal of Pharmaceutical Investigation
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• v.30 no.1
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• pp.55-59
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• 2000

Bioequivalence of two cisapride tablets, test drug ($Cisple^{\circledR}$ tablet: Hanmi Pharm Co., Ltd.) and reference drug ($Prepulsid^{\circledR}$ tablet: Janssen Pharm. Co., Ltd.), was evaluated according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty two healthy male volunteers were divided randomly into two groups and administered the drug orally at the dose of 10 mg as cisapride in a $2{\times}2$ crossover study. There was a week washout period between administrations. Blood samples were taken at predetermined time intervals for 36 hr and the plasma concentration of cisapride was determined by a HPLC method. $AUC_{0-36hr}$ (area under the plasma concentration-time curve from time zero to 36 hr), $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were estimated from the plasma drug concentration-time data. Analysis of variance (ANOVA) revealed no difference in $AUC_{0-36hr},\;C_{max}\;and\;T_{max}$ between two products. The apparent differences of these parameters between two products were less than 20% (i.e., 5.38, 6.17 and 0.00% for $AUC_{0-36hr},\;C_{max}\;and\;T_{max},$ respectively). The powers $(1-\beta)$ for $AUC_{0-36hr},\;C_{max}\;and\;T_{max}$ were over 0.9. Minimal detectable differences $(\Delta)$ at ${\alpha}=0.05,\;1-{\beta}=0.8$ were less than 20% (i.e. 17.67, 14.84 and 19.72% for $AUC_{0-36hr},\;C_{max}\;and\;T_{max},$ respectively). The 90% confidence intervals $(\delta)$ for these parameters were also within ${\pm}20%$ $(i.e.\;-4.97\;{\le}{\delta}{\le}\;15.73,\;-2.53{\le}{\delta}{\le}\;14.86\;and\;-11.55{\le}{\delta}{\le}\;11.55$ for $AUC_{0-36hr},\;C_{max}\;and\;T_{max},$ respectively). These results satisfied the criteria of KFDA guidelines for bioequivalence, indicating the two tablets of cisapride were bioequivalent.