• Food Science and Biotechnology
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• v.15 no.3
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• pp.418-423
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• 2006

Egg white powders (EWPs) were produced after pH adjustment (PH 6-9) of fresh egg white, followed by spray-drying, and foaming and gelling properties of EWPs were examined. EWP produced after pH adjustment to 6.5 (EWP-6.5) resulted in significantly higher foaming ability and gel hardness than control and other pH-adjusted EWP. Significant increases in surface -SH content and surface hydrophobicity of EWP-6.5 coincided with improved foaming ability and gel hardness. Significantly higher consistency index for reconstituted EWP-6.5 indicates unfolding of egg white protein was substantially increased in EWP-6.5. Decreased a-helix content in EWP-6.5 was confirmed by circular dichroism spectral analysis. These results indicate pH adjustment prior to spray-drying leads to structural changes in egg white proteins, significantly affecting major functionalities of EWP.

• Journal of the Korean Institute of Gas
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• v.25 no.1
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• pp.7-13
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• 2021

The re-liquefaction drum is a product that installed spray nozzles at the top to directly spray overcooled LNG into evaporative gas and installed demistors to facilitate gas separation, which was developed to increase the re-liquidity efficiency of small scale re-liquefaction facilities. In the hydrostatic test of the drum, no leakage occurred even at a pressure of 1.5 times the design pressure, but during the BOR(Boil Off Rate) test, the bolt loosening occurred due to contraction and expansion by temperature change. For the continued use of the product, insulation construction on flange connections was developed to enable detachment and attachment, and the comparison of heat load with existing insulation confirmed that it was very small compared to the inlet flow rate in the drum.

• Journal of Biosystems Engineering
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• v.36 no.6
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• pp.407-415
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• 2011

Damage to agricultural production caused by insects and diseases affects farming yields. The orchard sprayer is mainly used in the country to protect the fruit in a large area, with less effort and at minimum cost. The excellent performance of the air blast spray increases the fruit protection. Chemical application in orchards has been accomplished by the orchard sprayers with air assist nozzles and a axial fan in Korea. However, the orchard sprayers without ROPS resulted in severe injury or death when operators drive the sprayers improperly on hilly orchard or farming road. This study was to develop a ROPS for the orchard sprayers improving farmer's safety. In this study, the accident case was used in analysing the design and building TOP structure of the orchard sprayer. The maximum impact, body torsion frame structures including the driver's protection are also analysed for adherence to safety regulations. The ROPS safety regulations according to the strength test results were established.

• Journal of Pharmaceutical Investigation
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• v.41 no.4
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• pp.239-247
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• 2011

Simvastatin is an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, which catalyzes the conversion of HMG-CoA to mevalonate, an early and rate-limiting step in the biosynthesis of cholesterol. Simvastatin has good permeability, but it also has low solubility (BCS class II), which reduces its bioavailability. To overcome this problem, a solid dispersion is formed using a spray-dryer with polymeric material carrier to potentially enhance the dissolution rate and extend drug absorption. As carriers for solid dispersion, Gelucire$^{(R)}$44/14 and Gelucire$^{(R)}$ 50/13 are semisolid excipients that greatly improve the bioavailability of poorly-soluble drugs. To avoid any toxic effects of an organic solvent, we used aqueous medium to melt Tween$^{(R)}$ 80 and distilled water. The structural behaviors of the raw materials and the solid dispersion were analyzed by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). The DSC and PXRD data indicated that the crystalline structure of simvastatin was transformed to an amorphous structure through solid dispersion. Then, solid dispersion-based tablets containing 20 mg simvastatin were prepared with excipients. Dissolution tests were performed in distilled water and artificial intestinal fluid using the USP paddle II method. Compared with that of the commercial tablet (Zocor$^{(R)}$ 20 mg), the release of simvastatin from solid dispersion based-tablet was more efficient. Although the stability study is not complete, this solid dispersion system is expected to deliver poorly water-soluble drugs with enhanced bioavailability and less toxicity.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.1
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• pp.54-61
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• 2005

Characteristics of sprays injected by gas/liquid coaxial atomizers operated at atmospheric pressure are studied using shadowgraph, mechanical patternator and PDPA. The gas-to- liquid momentum flux ratio(M) and the liquid Reynolds number(Re) are selected as key parameters in characteristics of gas/liquid coaxial sprays from the dimensional analysis. The properties of shear coaxial sprays are compared with those of swirl coaxial sprays through the macroscopic and microscopic analysis. Macroscopic similarities between shear and swirl coaxial sprays are revealed under flow conditions of high momentum flux ratio. Also, empirical correlations between the mean drop diameters(D32) and operating conditions of coaxial sprays are proposed in this paper.

• Journal of Powder Materials
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• v.25 no.1
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• pp.54-59
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• 2018

Sb-doped $SnO_2$ (ATO) transparent conducting films are fabricated using horizontal ultrasonic spray pyrolysis deposition (HUSPD) to form uniform and compact film structures with homogeneously supplied precursor solution. To optimize the molar concentration and transparent conducting performance of the ATO films using HUSPD, we use precursor solutions of 0.15, 0.20, 0.25, and 0.30 M. As the molar concentration increases, the resultant ATO films exhibit more compact surface structures because of the larger crystallite sizes and higher ATO crystallinity because of the greater thickness from the accelerated growth of ATO. Thus, the ATO films prepared at 0.25 M have the best transparent conducting performance ($12.60{\pm}0.21{\Omega}/{\square}$ sheet resistance and 80.83% optical transmittance) and the highest figure-of-merit value ($9.44{\pm}0.17{\times}10^{-3}{\Omega}^{-1}$). The improvement in transparent conducting performance is attributed to the enhanced carrier concentration by the improved ATO crystallinity and Hall mobility with the compact surface structure and preferred (211) orientation, ascribed to the accelerated growth of ATO at the optimized molar concentration. Therefore, ATO films fabricated using HUSPD are transparent conducting film candidates for optoelectronic devices.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.97-97
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• 2017

This study investigated the corrosion protection by electrodeposited copper layer on AZ31 Mg alloy with and without additional silver layer by immersion test, salt spray test, OCP transient and potentiodynamic polarization experiment. The single electrodeposited Cu layer on AZ31 Mg alloy showed a nodular structure with many imperfections of crevices between the nodules, which resulted in the fast initiation of pitting corrosion within first few hours of immersion. Double-layer coating of Cu and outer Ag layer slightly increased the initiation time for pitting corrosion. Triple-layer coatings of Cu/Ag/Cu exhibited the most efficient corrosion protection of AZ31 Mg alloy, compared to the single- and double-layer coatings. Surface morphology of the outer Cu layer in the triple-layer was changed from the nodular structure to fine particle structure with no crevices due to the presence of an additional Ag layer. Thus, the improved corrosion resistance of AZ31 Mg alloy by electrodeposited Cu/Ag or Cu/Ag/Cu layers is readily ascribed to the decreased number of imperfections in the electrodeposited layers due to the additional silver layer. It is concluded that the additional silver layer provides many nucleation sites for the second Cu plating, resulting in the formation of finer and denser structure than the first Cu electrodeposit.

• Journal of ILASS-Korea
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• v.6 no.3
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• pp.8-16
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• 2001

The present study is focused on modeling the transient behavior of the local flame structure which is especially important for slow reaction processes, such as NOx formation in the radiating flame field. The unsteady flamelet model recently developed has been applied to analyze a steady, turbulent jet flame. Numerical results are compared with experimental data and numerical results of the conventional steady flamelet model. The numerical result reveals that the unsteady flamelet model correctly predicts the nonequilibrium effect upsteam and the subsequent decay of the superequilibrium radical concentrations further downstream.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.170-171
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• 2014

The buildings constructed with steel structure is coated with certified fire resistive material to resist from fire. Coating materials lose their initial performances as time passes, so they need some maintenance. This study is covers standardization of the methods for assessing the durability of SFRM. In Korea, more than 90 percent of SFRM are used indoors. So This study is to decide proper test method through investigation and examination of effect factor to performance of fire-resistant structure and applicable test method.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.10a
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• pp.134-138
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• 1995

The reinforced concrcte structure were once belicved to have permanent durability. However, it is now spoiled by durability failure caused by the corrosion of embeded steel reingorcement carbonation. alkali-aggregate reaction and salt attack Recently. salt damage has been also spreading. Salt damage is found in concrete structures built using seasands or certain admixtures containing calcium chlorides and in coastal structures frequently caught in seawater spray or blown by seawind It is the aim of this study to investigate the performance and application of new repair system for the exterior wall according to the durability improvement in the RC structures.