• Journal of the Korean Society of Clothing and Textiles
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• v.36 no.2
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• pp.127-137
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• 2012

This study focuses on the optimal washing conditions for dry cleaning recommended fabrics to minimize dimensional changes using wet cleaning. We suggest water-based alternatives to a perchloroethylene based cleaning process. Wool and rayon fabrics were laundered under various washing conditions and then air-dried for 24hrs. All specimens were extended after spinning and shrunk after drying. This is probably because the fibers were swollen and extended by wetting. The wool fabrics were shown to be acutely influenced by washing temperature and mechanical force. The optimal washing conditions for wool fabric to minimize the dimensional change implied a normal washing temperature and minimized mechanical force. For rayon specimens, dimensional change by a hand wash showed a remarkable decrease compared with a machine wash. Rayon fabric seemed to be influenced by the quantity of water contained in the fabric after spinning and washing time. Therefore, the desirable washing conditions for rayon fabric are to reduce the time required for washing and to increase the spin speed.

• Journal of Fashion Business
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• v.7 no.2
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• pp.69-81
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• 2003

Among the various properties of textile fabrics, the moisture-related properties are important for the textile processes or the apparel comfort characteristics. Alkaline hydrolysis results in pitting on the surface of fibers and increases the amount of hydroxyl and carboxyl end groups of the PET molecules on the fiber surface. The purpose of this study is to investigate the moisture-related properties of PET fabrics treated with quaternary ammonium compound/alkaline solution. The wetting and wicking properties of the PET fabrics were measured using the following experiments: contact angle, surface free energy, work of adhesion, vertical wicking height, moisture regain, and frictional static voltage. It was concluded that by the alkaline hydrolysis process, surface hydrophilicity and reactivity were considerably improved especially at lower levels of weight loss% and that the pitting of the fiber surface resulted in at higher levels of weight loss% was disadvantageous in moisture-related properties of PET.

• Journal of the Korean Ceramic Society
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• v.35 no.3
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• pp.303-309
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• 1998

The fabrication of Al2O3/Al composite by pressureless infiltration was investigated by the change of Mg and Si content in Al alloy infiltration process and infiltration atmosphere. The effect of alloying elements infiltration atmosphere and interfacial reactants between Al alloy matrix and Al2O3 particles were in-vestigated in terms of bendingstrength and harness test,. The fabrication of Al2O3/Al composite by the vestigated in terms of bending strength and hardness test. The fabrication of Al2O3/Al composite by the pressureless infiltration was done in nitrogen atmosphere with Mg in Al alloy. It was successfully fabricated at $700^{\circ}C$ according to Mg contents in Al alloy and infiltration condition. Because Mg in the Al alloy and ni-trogen atmosphere of infiltratio condition produced Mg-N compound(Mg3N2) it decreased the wetting an-gle between molten Al alloy and Al2O3 particles by coating on surface of Al2O3 particles. The fracture strength of Al2O3/Al-Mg composite was 800MPa and Al2O3/Al-Si-Mg composite was 400MPa. Si in Al alloy decreased the interfacial strength between Al alloy matrix and Al2O3 particles.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.1
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• pp.9-15
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• 2013

This study is to evaluate the parameter behavior of VfloTM distributed rainfall-runoff model by applying 3 kinds of rainfall interpolation methods viz. Inverse Distance Weighting (IDW), Kriging (KRI), and Thiessen network (THI). For the 1,544 $km^2$ Dongcheon watershed of Nakdong river, the model was calibrated using 4 storm events in 2007 and 2009, and validated using 2 storm events in 2010. The model was calibrated with Nash-Sutcliffe model efficiency of 0.97 for IDW, 0.94 for KRI, and 0.95 for THI respectively. For the sensitive parameters, the saturated hydraulic conductivity ($K_{sat}$) for IDW, KRI, and THI were 0.33, 0.31, and 0.43 cm/hr, and the soil suction head at the wetting front (${\Psi}_f$) were 4.10, 3.96, and 5.19 cm $H_2O$ respectively. These parameters affected the infiltration process by the spatial distribution of antecedent moisture condition before a storm.

• Bulletin of the Korean Chemical Society
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• v.25 no.5
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• pp.634-638
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• 2004

Titanium silicalite-1 (TS-1) molecular sieve was produced by microwave heating of amorphous titanium-containing solid precursors after impregnation with aqueous TPAOH solution. $SiO_2-TiO_2$ xerogel, sub-micron sized $SiO_2-TiO_2$ prepared by thermal plasma process, and Ti-containing mesoporous silica, Ti-HMS, were tested as the solid phase substrates. Highly crystalline product was obtained within 30 min. after microwave irradiation with yields over 90% using $SiO_2-TiO_2$ xerogel, which showed essentially identical physicochemical properties to TS-1 prepared by conventional hydrothermal method. Excellent catalytic activity was also obtained for 1-hexene epoxidation using $H_2O_2.\;SiO_2-TiO_2$ particles prepared by thermal plasma and Ti-HMS were found inferior as a substrate for TS-1, probably due to difficulties in wetting the surface uniformly with TPAOH.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.3
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• pp.517-526
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• 2017

The biodegradation and water absorption properties of lignin/poly(vinyl alcohol) (PVA) nanofibrous webs are investigated. Lignin/PVA nanofibrous webs containing 0, 50, and 85wt% of lignin were prepared via an electrospinning process to observe the effect of the lignin concentration on the biodegradability and water absorption properties of lignin/PVA nanofibrous webs. The morphology of the materials was examined by field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). To understand the wetting behavior and hydrophilic nature of the electrospun lignin/PVA nanofibrous webs, the water absorbency, contact angle, and water uptake were examined. The enzymatic degradation of lignin/PVA nanofibrous webs was investigated using laccase by measuring total organic carbon (TOC) concentration over a course of 50 days. Water drops were absorbed immediately into all of the specimens. The water uptake of lignin/PVA nanofibrous webs increased as the amount of PVA in the lignin/PVA hybrid webs increased. The enzymatic degradation experiment indicated that the inherent biodegradability of lignin was retained after its transformation into nanofibers. Our findings imply that blending these two types of polymers is promising because it can lead to the development of a new range of multifunctional materials such as antimicrobial absorbent nanotextiles based on sustainable biopolymers.

• The Korean Journal of Pesticide Science
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• v.8 no.4
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• pp.272-279
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• 2004

The process for the preparation of fungicide propineb starting with 1,2-diaminopropane was studied on the optimal condition base. Side reaction producing toxic material 1,2-propylenethiourea could be ieduced effectively by using phase transfer catalyst and the product was noticed to show a great improvement in yield and purity. Especially when the phase transfer catalyst tetraphenylphosphonium bromide is used, the yield and the purity of the product were found to be best with up to 95 and 96% respectively and the byproduct content was shown within 1.7%. Also, the contents of wetting agent AES and dispersing agent APS were optimally chosen $3.1\sim4.0%$ and $4.0%\sim5.0%$ respectively for the improvement of suspensibility and wettability of Propineb WP.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3_1spc
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• pp.544-550
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• 2013

A grooved surface with anisotropic wettability was fabricated on a silicon substrate using photolithography, reactive ion etching, and a KOH etching process. The contact angles (CAs) of water droplets were measured and compared with the theoretical values in the Cassie state and Wenzel state. The experimental results showed that the contact area between a water droplet and a solid surface was important to determine the wettability of the water. The specimens with native oxide layers presented CAs ranging from $71.6^{\circ}$ to $86.4^{\circ}$. The droplets on the specimens with a native oxide layer could be in the Cassie state because they had relatively smooth surfaces. However, the CAs of the specimens with thick oxide layers ranged from $33.4^{\circ}$ to $59.1^{\circ}$. This indicated that the surface roughness for a specimen with a relatively thick oxide layer was higher, and the water droplet was in the Wenzel state. From the CA measurement results, it was observed that the wetting on the grooved surface was anisotropic for all of the specimens.

• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.1
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• pp.81-89
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• 1995

The aim of the work described in this paper is to develope a constitutive model for the prediction of an unsaturated Soil and to confirm the application of the model, which is composed of the elastic and plastic part in consideration of the matric suction and the net mean stress. From test results, volume changes and deviator stresses are analyzed at each state and their relationships are formulated. And the application of the model to silty sands is con- firmed by the comparison between test and predicted results. During drying-wetting and loading-unloading processes for isotropic states, the agreement between predicted and test results are satisfactory. And predicted deviator stresses are well agreed with test results in shearing process. Overall acceptable predictions are reproduced in high confining pressure. Usefulness of the model is confirmed for the unsat- urated soil except volumetric strain, which is not well agreed with the test results due to deficiency of dilatancy of the model in low confining pressure. It is, therefore, recom- mended to study the behavior of dilatancy for an unsaturated soil.

• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.3
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• pp.101-110
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• 1996

The aim of the work described in this paper is to develope a constitutive model for the prediction of an unsaturated clayey soil and to confirm the application of the model. To this end a series of suction controlled isotropic and triaxial compression tests are conducted on clayey soils. Matric suction is controlled by the axis translation technique using high air entry ceramic disk. Total volume change, air and water volume changes are measured by the device made for the experiment. The specimens are compacted by dynamic compaction using a half of Proctor compaction energy with the water contents of 5% drier than the optimum moisture contents. From test results, volume changes and deviator stresses are analyzed at each state and their relationships are formulated. And the application of the model to clayey soils is confirmed by the comparison between test and predicted results. During drying-wetting and loading-unloading processes for isotropic states, the agreement between predicted and test results are satisfactory. And predicted deviator stresses are well agreed with the test results in shearing process, but volumetric strain is not well agreed with the test results in high suctions.