• Journal of Pharmaceutical Investigation
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• v.3 no.3
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• pp.5-15
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• 1973

The stabilizing effect of promazine hydrochloride injectin was tested by irradiation of sun lamp(5,000 Lux) on their acid solution sealed in ampules under various stabilizers. The result of experimentation on the color change, the remaining proportion and the half life of promazine hydrochloride solution is as follows. 1. Instability of promazine hydrochloride solution is mainly caused by the sunlight and oxygen. 2. The pH range of promazine hydrochloride injection is recommended to $pH\;4.4{\sim}5.2$ 3. The decomposition of promazine hydrochloride by the sunlight is composed of pseudo zero order reaction when It maintains colorless solution. 4. The half life of 0.5% promazine hydrochloride injection was 30 hrs. under sun lamp irradiation, but it was delayed to 84 hrs. by the simple stabilizer and to 175 hrs. by compound stabilizer. 5. The stabilizing effect of promazine .hydrochloride injection adding sod. metabisulfite$(Na_2S_2O_5)$ was most excellent in various simple stabilizers and adding $Na_2S_2O_5$ to nicotinic acid, $Na_2S_2O_5$ to nicotinamide were more excellent than other compound stabilizers.

• Journal of Family Resource Management and Policy Review
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• v.12 no.1
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• pp.159-176
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• 2008

The purpose of this study was to review housework research studies in the Journal of Korean Home Economics Association, the Journal of Korean Home Management Association and the Journal of Korean Family Resource Management Association. For this purpose, 109 housework research studies were analyzed according to the themes, published years, the subjects and the research methods. The major findings of this study were as follows. The research on the evaluation of the value of housework was the theme most frequently studied, followed by research on the socialization of housework, housework time, the attitudes on and satisfaction with housework, and the division of housework, in that order. During the periods of 1990-2000 years, housework studies had increased, but since then have slowly decreased. The majority of respondents to housework studies were married women. With respect to employment status of the subjects, both employed and unemployed people were sampled in half of the studies. The sample size was over 300 in almost half of the research reviewed. The most frequently used research method was the surveys using questionnaires. Descriptive statistics, one way ANOVA and multiple regression analysis were the statistical methods used most frequently.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.297-300
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• 2001

The SMZ half-bridge converter uses the resonance between the inductance of transformer and the resonant capacitances to transfer the input power to the load. In addition to this kind of characteristic of the converter, there are some features such as the capability of soft switching operation, a lower switching loss, and a higher power density in the converter. However in the low-voltage and high-output current applications of the converter, the extremely increased output ripple voltage prevents the converter from normal operation. In order to overcome the drawback of the converter, adding the output filter inductor to the converter, the converter shows the completely different resonant characteristics. In this paper, We analyzed the resonant characteristics of the SMZ converter with the output filter inductor and investigated what the analyzed results affect the converter operation. The experiment of a I50W prototype SMZ converter with 5V output and 310V input is carried out to verity the validity of the analyzed results.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1039-1040
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• 2006

The resonant converters cause the high voltage stress according to the input voltage, which increases the conduction loss in converter power switches. The topology of LLC half bridge resonant converter provides ZVS characteristic and also the stress of voltage and current is not higher than that of the general resonant converters. So we can expect the higher efficiency. In this paper, the LLC resonant converter is designed for the notebook computer adapter. In the adapter design, we should consider the weight, the size and overheat of the adapter. Thus the higher efficiency is an essential particular. First of all, the optimal design of transformer is the most important facts. Some parameters should be considered in order to get the highest efficiency. The adapter is designed through the considering of these parameters including the PFC circuit of the pre-regulator. It converts AC line input into about $400V_{DC}$ Link voltage of the LLC converter input and the converter has $16V_{DC}/90W$ ratings. The efficiency measured is about up to 92%.

• Nuclear Engineering and Technology
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• v.48 no.5
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• pp.1230-1236
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• 2016

This study aims to determine the effect of fly ash with a high replacing ratio of clay on the radiation shielding properties of bricks. Some interaction parameters (mass attenuation coefficients, half value layer, effective atomic number, effective electron density, and absorption efficiency) of clay fly ash bricks were measured with a NaI(Tl) detector at 661.6 keV, 1,173.2 keV, and 1,332.5 keV. For the investigation of their shielding behavior, fly ash bricks were molded using an admixture to clay. A narrow beam transmission geometry condition was used for the measurements. The measured values of these parameters were found in good agreement with the theoretical calculations. The elemental compositions of the clay fly ash bricks were analyzed by using an energy dispersive X-ray fluorescence spectrometer. At selected energies the values of the effective atomic numbers and effective electron densities showed a very modest variation with the composition of the fly ash. This seems to be due to the similarity of their elemental compositions. The obtained results were also compared with concrete, in order to study the effect of fly ash content on the radiation shielding properties of clay fly ash bricks. The clay fly ash bricks showed good shielding properties for moderate energy gamma rays. Therefore, these bricks are feasible and eco-friendly compared with traditional clay bricks used for construction.

• YAKHAK HOEJI
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• v.41 no.1
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• pp.81-85
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• 1997

Ceramide has been suggested as an important mediator of the effects of extracellular agonists on cell growth inhibition, differentiation, apoptosis. However the biochemical sign aling mechanism involved in transducing the effects of ceramide on leukemia cell differentiation is still unclear. In these respects, we examined the regulatory effects of ceramide on c-jun gene expression during differentiation. In U-937 cells. ceramide increased c-jun mRNA levels in a time-dependent manner. The half life, of c-jun mRNA was 30 min. In contrast, inhibition of protein synthesis with cycloheximide in the absence, of transcription with actinomycin D increased the half-life of c-jun mRNA in ceramide-treated U-937 cells to more than 90 min. In order to examine whether ceramide-inhibited c-jun gene expression is regulated through ceramide-activated protein phosphatase (CAPP), a direct target for the action of ceramide, okadaic acid were treated to the cells. Okadaic acid inhibited enhancement of c-jun mRNA induced by C2-ceramide in a dose-dependent manner. These results suggested that ceramide increases c-jun mRNA level during differentiation in U-937 cells and regulates the gene expression on posttranscriptional level. In addition, we provide the evidence that CAPP is involved in ceramide-induced c-jun gene expression in U-937 cells.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.1
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• pp.39-48
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• 2005

Nitrogen and sulfur deposition was measured on Lake Pal dang from March 2002 to October 2003. Wet and dry depositions were separately measured using wet- and dry-only samplers, respectively. In order to measure the dry deposition to the water body, a dry deposition sampler composed of three pans filled with pure water, called the deposition water, was used. Since ammonium was generally in excess in ambient air, more than half of ammonium was present in the gaseous form. Ammonium concentration was also generally higher than the sum of major anion concentrations in the deposition water because gaseous species were much easily deposited than the species in fine particles. Nevertheless, the contribution of gaseous ammonia to the deposition of ammonium was not high as well as that of particulate ammonium while the contribution of gaseous nitric acid was much higher than that of particulate nitrate. Annual wet deposition fluxes of nitrogen and sulfur were five and six times higher than their dry deposition fluxes, respectively. Except for ammonium, the dry deposition flux estimated in the present work was a half of the previous results. This was mainly caused by much smaller dry deposition velocities over the water than over the ground.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2004.11a
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• pp.179-180
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• 2004

In the information society, individual, enterprise and nation must be equipped with environmment and competence with which they can acquire useful information anytime and anywhere to process and utilize it in required form. Therefore, this study intends to investigate how digital TV, refrigerator and computer are laid out in the residential space in terms of life space, analyze the preference of residents an d forecast the preferred functions of the products to be introduced in the future. To build frame for making questionnaire tool of this survey, 3 households of the first constructor among the top-ranked constructors in the first half of 2004 were chose and in-depth interview was made from April 12 to April 17. On the basis of result of preliminary survey obtained by this process, the questionnaire was revised and supplemented. Targeting those living at the apartment house in Seoul and constructors ranked in top-four in the order of construction of the first half of 2004, I selected 3 households for each group in the range of 30$^{\sim}$40 pyung. Twelve cases were surveyed from April 19, 2004 to June 5, 2004. First, TV will continue playing the role of central entertainment mustering family at one place rather than separating them to each room. Second, in the case of refrigerator, the function is being subdivided, making 2 types, refrigerator and kimchi refrigerator indispensable, which was in just unit in the past Third, while computer was usually placed in the individual bedroom,

• Journal of Power Electronics
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• v.13 no.1
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• pp.70-76
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• 2013

For high power high step-down dc-dc conversion applications, conventional three-level dc-dc converters are subject to extreme duty cycles or increased volume and cost due to the use of transformers. In this paper, a transformerless three-level dc-dc buck converter with a high step-down conversion ratio is proposed. The converter comprises two asymmetrical half bridges, which are of the neutral point clamped structures. Therefore, the output pulse voltage of the converter can be obtained in terms of the voltage difference between the two half bridges. In order to realize harmonious switching of the converter, a modulation strategy with capacitor voltages self balance is presented. According to the deduced output dc voltage function, transformerless operation without extreme duty cycles can be implemented. Experimental results from a 1kW prototype verify the validity of the proposed converter. It is suitable for ship electric power distribution systems.

• Journal of the Microelectronics and Packaging Society
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• v.16 no.1
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• pp.39-43
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• 2009

In order to develop piezoelectric inverter module for CCFL driving, Rosen-type multilayer piezoelectric transformer was fabricated. The output power and efficiency of mutilayer piezoelectric transformer according to the variation inner electrode layer were investigated. Mutilayer piezoelectric transformer was fabricated conventional mutilayer ceramic method using PZT base ceramics. Also, piezoelectric inverter module was adopted driving circuit with half-bridge type. The piezoelectric inverter module was set up with input voltage 12.5 V, switching frequency 104.3 KHz. The results showed the value of step-up ratio 100, efficiency 87% at load resistance of $100k{\Omega}$.