• The Research Journal of the Costume Culture
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• v.17 no.4
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• pp.535-547
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• 2009

This study presented a making method of jeans pattern with high fitness after deriving the appropriate shrinkage rate by material and washing process. For this purpose of this study, 6 jeans have been tested after washing finishing and we turned out appropriate shrinkage rate by evaluating the exterior of jeans and usage satisfaction. Then, a making method of jeans pattern was presented after applying the optimized shrinkage rate. According to the result of the exterior evaluation of test jeans, all 6 jeans were rated high with scores close to 3.5. Following the evaluation of satisfaction of usage by physical movement, the highest ranking was in the order of walking with normal steps, back bending $90^{\circ}$, chair sitting, climbing stairs, and squatting. The shrinkage rate by physical area showed the highest score in the order of pants length, waist circumference, thigh circumference, knee circumference, hem circumference, hips circumference. In addition, the shrinkage rate was higher in warp direction than weft direction after washing finishing. As for the result of addition and reduction of pattern measurements by parts of jeans, waist circumference was 2.6${\sim}$5.2cm, hips circumference was 1.3${\sim}$4.2cm, thigh circumference was 0.8${\sim}$3.1cm and knee circumference was 0.7${\sim}$2.5cm. Also, hem circumference was 0.5${\sim}$1.8cm and pants length was 4.0${\sim}$6.2cm. That is, this results showed a wide range of addition and reduction according to material and washing finishing.

• Corrosion Science and Technology
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• v.6 no.1
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• pp.12-17
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• 2007

Portland cement incorporating supplementary cementing material develops excellent mechanical properties and long term durability characteristics. India is a leading rice producing country and rice husk is considered as waste in the rice milling industries. In this present work, the rice husk ash (RHA) was added to concrete as cement replacement from 0 to 30%. Corrosion performance of reinforcing steel embedded in RHA blended concretes was studied using linear polarization, AC impedance and gravimetric methods. The corrosion rate of steel bars embedded in RHA concretes were compared with control concrete. The results clearly indicate that the corrosion rate of reinforcing steel embedded in concrete is significantly reduced with the incorporation of RHA. A good correlation among gravimetric method and electrochemical methods was observed. Electrochemical impedance study showed 98 percentage reduction in corrosion rate to the RHA blended concrete with 15% replacement than control concrete.

• Journal of Powder Materials
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• v.10 no.5
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• pp.349-352
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• 2003

This study examined the correlation of various operational factors including reaction temperature and the quantity of reductant and diluent with the characteristics of powder using $K_2$ TaF$_{7}$ as feed materials, Na as a reductant and KCl/KF as a diluent. Also to control the particle size and shape, external supply system developed, it can provide a feed material and a reductant at a fixed quantity and evaluated the characteristics of tantalum powder. When the external supply system was applied instead of the batch type process that charges feed material, reductant and diluent at the same time, it was possible to induce regular reduction reaction between feed material and reductant, which increased the recovery rate and reduced the mixture of impurities. In particular, the application of the external supply system enabled the control of reaction temperature and reaction speed according to the feeding rate of feed material during reduced reaction, and resultantly it enabled the manufacturing of granular-shaped powder with a regular granularity of 2∼3 ${\mu}{\textrm}{m}$ and purity of 99.5%.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.3
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• pp.263-278
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• 2022

This paper contains experimental study for the development and performance of TBM backfill material with thixotropic properties. The LW backfill material is widely applied to fill the cavity on the back side of the shield TBM excavation, but has disadvantages such as settlement caused by strength reduction, material separation by groundwater, and reduced plasticity. In this paper, laboratory tests and a model test were conducted to assess the performance of inorganic thixotropic backfill material proposed to improve these problems. The results of laboratory tests show that 1 hr-uniaxial compressive strength of ITB was 12 times higher than LW, and the rate of bleeding of 20 hr was 8.3 times lower, and the result of flow table test was more than 27 times higher. This result indicated that the inorganic thixotropic backfill material has superior properties to LW backfill in terms of strength reduction, material separation, and thixotropy. In the model experiment, a model injection device tester was manufactured and the injection performance and filling rate were verified. When material was injected in the water, it was visually checked whether material separation occurred, and it was confirmed that the filling rate was 96% or more. Comparison results with the test of LW and ITB materials was concluded that ITB can reduce the material separation by groundwater and the occurrence of tunnel cavity.

• Applied Chemistry for Engineering
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• v.17 no.4
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• pp.369-374
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• 2006

$Rh-Pt/Al_{2}O_{3}$ catalysts were used for the first time to study its reaction characteristics in the asymmetric hydrogenation of ethyl pyruvate. The catalysts were prepared either by impregnation of Rh on a commercial $Pt/Al_{2}O_{3}$ or by sequential impregnation of Rh followed by impregnation of Pt on $Al_{2}O_{3}$. Reaction rate and enantiomeric excess (ee%) were compared according to the preparation method, Rh contents, and the reduction temperature of the catalyst. The physical characteristics of the catalysts were analyzed using XRD and TEM. Bimetallic $Rh-Pt/Al_{2}O_{3}$ catalysts showed an improved reaction rate and optical purity (63.6 ee%) with increasing the reduction temperature. The variation of the Rh contents as well as the preparation method elicited a big difference on the reaction rate, while enantiomeric excess (ee%) was lower (56~60%) with all bimetallic catalysts than with monometallic $Pt/Al_{2}O_{3}$ catalyst.

• The Journal of the Korea Contents Association
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• v.14 no.2
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• pp.457-466
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• 2014

During irradiation of lesions in cancer treatment with high energy electrons, normal tissue and critical organs are protected by the shielding material. Scattered radiation that generated the shielding materials affect the depth dose and atomic number. Therefore, we want to examine secondary particles and the scattered photons through calculation and its associated analysis, and compare the measurement for the aluminum, copper, and lead shielding substance of which thickness has 95% charge reduction. Dose change rate which effected scattering radiation was found to be +0.88% for material thickness, +0.43% for atomic number, and +19.70%, +15.20%, +12.40% for measurement, +25.00%, +15.10%, +13.70% for calculation on the aluminum, copper, and lead materials of which thickness has 95% charge reduction, respectively, As a result, we found that scattering rate was dependent on thickness than atomic number. In the dose increasing rate, scattered electrons are more important than scattered photon. For the above mentioned reasons, I think that high atomic number materials should be applied to reduce scattered radiation that generated with thickness effect.

• Journal of Power System Engineering
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• v.21 no.1
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• pp.50-56
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• 2017

To increase the enthalpy exchange efficiency of ERV elements, the moisture exchange character must be improved. The moisture exchange efficiency depends on material characteristics. The material used for ERV is Hwang-to paper based on Han-ji which is Korean traditional paper. The paper has excellent performance in moisture exchange and heat transfer compared with polymer and other papers. To have an anti bacteria performance and to improve moisture exchange performance of Han-ji, Hwang-to is added to the Han-ji. The enthalpy exchange efficiency of the Hwang-to paper shows 5% greater than that of the conventional paper. In case of Escherichia Coli, the reduction rate of bacteria is 96.6% and in case of Pseudomonas, the reduction rate of bacteria is 97.5%. The ERV element made of Hwang-to paper has a great possibility as an ERV element.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.216-217
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• 2007

In this study, we analyzed the electrical loss characteristics between ribbon and output terminal of constituent material according to electrical resistance during interconnection process of PV module. From this result, the electrical output power reduction rate caused by interaction between ribbon and cell's interconnection was 2.88%. There was 1W electrical output power reduction through the 16 solar cells. So it is expected that the wider size of PV module gives the higher loss in electricity production. Also, the average output power of PV module passed lamination process was increased by 0.081W per one solar cell and the increase rate was 3.7%.PV module's electrical loss before and after lamination process according to constituent material's terminal was 0.49W and 0.50W, respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.4
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• pp.241-246
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• 2016

ZnO thin films have wide application areas due to its versatile properties as transparent conductors, wide-bandgap n-type semiconductors, gas sensor materials, and etc. We have performed a systematic investigation on ultraviolet-assisted CVD (chemical vapor deposition) method. Ultraviolet irradiation during the deposition of ZnO causes chemical reduction on the growing surface; which results in the reduction of the deposition rate, increase in the surface roughness, and decrease of the electrical resistivity. These effects produce larger characteristic variation with various deposition conditions in terms of surface morphology and optical/electrical properties compared to normal CVD deposited ZnO thin films. This versatile controllability of ultraviolet-assisted CVD can provide a larger processing options in the fabrication of nano-structured materials and flexible device applications.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.920-923
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• 2004

We have investgated on the monolayer LB film of BASH-DMPC mixture on an ITO for the photoisomerization by light irradiation. We measured electrochemical properties by using cyclic voltammetry with a three-electrode system, An Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode in $NaClO_4$ solution at a variable concentration and monolayer LB films. A measuring range was reduced from initial potential to -1350mV, continuously oxidized to 1650 mV and measured to the initial point. The scan rate were 50, 100, 150 and 200 mV/s. As a results, LB films of 8A5H-DMPC appeared reversible process caused by the reduction-oxidation current from the cyclic voltammogram.