• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.2
• /
• pp.333-338
• /
• 2007

An infernally confined hollow reinforced concrete pier (ICH RC pier) is hollow RC pier which has a internal steel tube to enhance its ductility and stiffness by internal confinement. In this study, the internal steel tube were changed to investigate the behavior of ICH RC pier. The behavior of internally confined hollow reinforced concrete piers were evaluated with safety ratio, ductility, total material cost, the total weight of the pier, etc. As a result of analytical study, the usage of a minimum necessary thickness of the internal steel tube the most effective. The ICH RC pier has decrease of weight compare to Solid RC pier.

• Korean Chemical Engineering Research
• /
• v.50 no.4
• /
• pp.621-626
• /
• 2012

In this study, the composite coating materials with improved thermal insulation property were prepared by incorporating the hollow micro-spheres with high heat transfer resistance. The UV curable resin system consisting of hexa aliphatic urethane acrylate (UP118), trimethylolpropane triacrylate (TMPTA), 1,6-hexanediol diacrylate (HDDA), and photoinitiator (Irgacure184) was employed as an organic binder. The glass substrates were coated by the prepared composites via bar coating method and cured under UV radiation. The optical transparency, thermal insulation property, adhesion, and surface hardness of the glass coated with composites containing different type of micro-spheres were investigated. The incorporation of micro-spheres with only 20 vol% of content resulted in remarkable improvement in the thermal insulation property of the coated glass. In addition, the transparent coated glass with light transmittance of about 80% could be obtained when silica micro-sphere (SP) was used as a thermal barrier.

• Membrane Journal
• /
• v.11 no.2
• /
• pp.66-73
• /
• 2001

Ivlain objectives of this work arc to investigate basic fouling characteristics and emxts of backpulsing on the fouJing control in the free-end membrane module uo

• Polymer(Korea)
• /
• v.33 no.5
• /
• pp.463-468
• /
• 2009

Syntheses of monodisperse and micron-sized hollow plastic pigment (HPP) were carried out through the core-shell reaction. The effects of the reaction parameters, such as the particle size, molecular weight, the swelling time, agitation rate, and the solid contect were investigated. This micron-sized HPP could be made by using the alkali soluble core with at least bigger than 200 nm size. To obtain a higher opacity ratio, the swelling time and molecular weight of the core should be controlled. The agitation rate affected the particle's morphology. To prevent the shell destruction, the agitation rate must be sufficiently low in case of the syntheses of micron-sized HPP. In this study, micron-sized HPP exhibiting the high hiding power and narrow particle distribution could be obtained.

• Membrane Journal
• /
• v.23 no.2
• /
• pp.176-184
• /
• 2013

To investigate the performance of VOC separation, composite hollow fiber membrane was prepared which composed of poly (ether imide) support prepared by phase separation method and poly (dimethylsiloxane) coating active layer. The performances of the membranes for the application of recovery process in terms of their morphology, gas permeance test for $N_2$ and $O_2$ gases. Durability against benzene, toluene and xylene was also investigated. And permeation test for multi-component VOCS through the membrane with different feed concentration and stage-cut were investigated. Permeance of PEI supported membrane and the membranes coated with PDMS decreased from 45,000 GPU to 63 GPU and 49,450 to 30 GPU for $N_2$ and $O_2$, respectively. Recovery efficiency and concentration of VOCs in permeate increased with decreasing stage-cut. VOCs concentration in permeate proportionally increased with increasing feed concentration but concentration ratio and recovery efficiency showed any noticeable changes with feed concentration change.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.10 no.4
• /
• pp.17-24
• /
• 2010

The hollow RC(Reinforced concrete) pier has the merit of lightweight pier compared with solid RC pier. However, the hollow RC pier shows a low ductile behavior due to brittle failure of inside concrete. To overcome this problem, the internally confined hollow reinforced concrete column has been developed. In this study, the behavior of internally confined hollow RC piers were evaluated with safety ratio, ductility, total material cost, the total weight of the pier, etc. The chosen parameters for the study are hollow ratio, thickness of internal steel tube, intervals between vertical re-bars, numbers of horizontal re-bars, and strength of concrete. As a result of parameters study, the usage of a minimum necessary thickness of the internal steel tube is the most effective.

• Korean Chemical Engineering Research
• /
• v.48 no.4
• /
• pp.423-427
• /
• 2010

Carbon nano sphere(CNS) and nano bowl of carbon(NBC) containing 1.0 wt% copper were prepared by impregnation method and their catalytic activity was compared in the phenol hydroxylation with hydrogen peroxide in the presence of water and acetonitrile as a solvent, respectively. Cu content of catalysts was determined by EDS, and BET, pore volume, pore size and pore size distribution were compared. For both catalysts, phenol conversion, $H_2O_2$ efficiency and yield of catechol and hydroquinone were higher in the presence of water as a solvent than those in the presence of actonitrile. And catalytic activity such as phenol conversion and $H_2O_2$ efficiency of 1.0 Cu/CNS is about two times higher than that of 1.0 Cu/NBC in water solvent.

• Polymer(Korea)
• /
• v.30 no.2
• /
• pp.175-181
• /
• 2006

Hybrid process of thermally-induced phase separation and stretching was developed for the preparation of microporous polypropylene hollow fiber membranes. Precursor for stretching was prepared by using soybean oil as a diluent and benzoic acid as a nucleating agent far the sphenlite control and it was stretched far the micrporous hollow fiber membrane. The effects of stretching ratio and deformation rate for stretching process were investigated. Increase of stretching ratio resulted in the greater pore size with nonuniform size distribution. Higher deformation rate also increaser the pore size with uniform size distribution. Stretching ratio was closely related with the orientation of polymer chain and increased the mechanical strength of the fiber. Increase of deformation rate had little effects on the orientation of crystalline phase, and decreased the orientation of amorphous phase which caused the decrease of tensile strength of the fiber and broke the micro-fibrils connecting spherulites to form a circular pore shape.

• Membrane Journal
• /
• v.26 no.2
• /
• pp.159-165
• /
• 2016

Polyimide hollow fiber membrane modules were prepared in order to investigate the process of multi stage gas separation. The modules performance was carried out using 50/50 of $N_2/SF_6$ mixed gas. The membrane modules has been tested for measuring gas flow rate and concentration under various stage cut at 0.5 MPa. The membrane modules showed a high recovery ratio at the same stage cut as $N_2/SF_6$ selectivity increased. Two stage process was fulfilled for improving $SF_6$ recovery ratio and $SF_6$ concentration. Eventually, two stage process showed higher performance of $SF_6$ recovery ratio and concentration ($SF_6$ recovery ratio = 95%, $SF_6$ conc. = 98%).

• Science of Emotion and Sensibility
• /
• v.17 no.4
• /
• pp.71-78
• /
• 2014

Composite draw textured yarns(DTY) and air jet textured yarns(ATY) with hollow PET filament have been used for making high emotional fabrics including light weight sports wear garments. This study investigated effect of hollow composite yarns and fabric structural parameters to the comfort properties related to the moisture and thermal transport phenomena for the composite fabrics made of DTY and ATY with hollow PET filament. Wicking property of hollow composite fabric was superior at the high pore size fabric and was not influenced by fabric cover factor. Wicking property of the fabric with ATY was better than that of the fabric with DTY. On the other hand, drying rate of fine pore sized fabric was shorter than that of large pore sized fabric and drying rate of high multi yarn fabric with low cover factor and small pore size was superior than that of hollow composite fabric. The pore size of the fabric was dominant factor in the air permeability and thermal conductivity of hollow composite fabric. High pore sized fabric showed high air permeability and thermal conductivity of hollow composite fabric was nonlinearly inversely proportional to pore size of the fabric.