• 한국의류학회지
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• 제28권6호
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• pp.819-829
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• 2004

This study was carried out to suggest a new swimsuit fabric with improved durability, comfort and appearance, by employing PTT(polytrimethylene terephthalate). Objective and subjective performances of newly woven PTT/PU (polyurethane) blend fabric were estimated and compared with nylon/PU(80/20) which is currently used for swimsuit. According to the questionnaire, the most serious problems of swimsuit fabrics were such that they were easily degraded by chlorinated water and this made fabric inelastic and transparent. After exposure to the chlorinated water, PTT blend fabrics showed higher retention of breaking strength, bursting strength, elastic recovery and crystallinity. suggesting that PTT/PU(87/13) was the most excellent material in durability. PTT blend fabrics absorbed less water and dried faster than nylon/PU and thus PTT/PU(87/13) was shown to be the best in respect of comfort. All of the specimens used in this study exhibited satisfactory colorfastness to sea water, chlorinated water and light except that nylon/PU(80/20) represented weak colorfastness to chlorinated water. From the subjective wearing sensation test, PTT/PU(82/18) was shown to posess the best wearing sensation. From the overall evaluation or objective and subjective properties, PTT blend fabrics exhibited superior performances to nylon/PU(80/20), suggesting that they can be successfully used as a new durable and comfortable swimsuit fabric.

• Nuclear Engineering and Technology
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• 제48권4호
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• pp.915-924
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• 2016

After a severe accident to the nuclear reactor, the in-vessel retention strategy is a key way to prevent the leakage of radioactive material. Nanofluid is a steady suspension used to improve heat-transfer characteristics of working fluids, formed by adding solid particles with diameters below 100nm to the base fluids, and its thermal physical properties and heat-transfer characteristics are much different from the conventional working fluids. Thus, nanofluids with appropriate nanoparticle type and volume concentration can enhance the heat-transfer process. In this study, the moving particle semi-implicit method-meshless advection using flow-directional local grid method is used to simulate the bubble growth, departure, and sliding on the downward-facing heating surface in pure water and nanofluid (1.0 vol.% $Al_2O_3/H_2O$) flow boiling processes; additionally, the bubble critical departure angle and sliding characteristics and their influence are also investigated. The results indicate that the bubble in nanofluid departs from the heating surface more easily and the critical departure inclined angle of nanofluid is greater than that of pure water. In addition, the influence of nanofluid on bubble sliding is not significant compared with pure water.

• Journal of Acupuncture Research
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• 제32권2호
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• pp.209-216
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• 2015

Objectives : The objective of this study was to report two cases that patients with external epicondylitis were improved by based on 'eight vacuity' theory bloodletting therapy, acupuncture therapy and bee venom pharmacopuncture. Methods : In this study, patients were treated with bloodletting therapy, then acupuncture therapy and bee venom pharmacopuncture to Ashi point on eight vacuity of elbow in the patients without retention of needles. Subsequently, electroacupuncture and Dong-qi acupuncture treatment were implemented in order to strengthen the effect of acupuncture. In terms of evaluation methods, visual analog scale(VAS) score, range of motion(ROM), grip strength and physical examination were used to assess external epicondylitis-related symptoms. Results : VAS score decreased, ROM and grip strength were increased and physical examination was improved in all cases. Conclusions : It was suggested that the symptoms of intractable external epicondylitis could be improved by eight vacuity theory adopted bloodletting therapy, acupuncture therapy and bee venom pharmacopuncture.

• 한국물환경학회지
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• 제27권5호
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• pp.563-571
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• 2011

The purpose of this study is to investigate the high strength ammonia oxidation of piggery wastewater. Laboratory scale reactors was operated using influent of piggery wastewater and effluent of anaerobic digester from piggery wastewater at $35^{\circ}C$ and $20^{\circ}C$. Results of various operating conditions were compared and analyzed. After analyzing the results, effluent of anaerobic digester from piggery wastewater required shorter Solid retention time (SRT) than influent of piggery wastewater. In terms of the temperature, stable ammonia removal and denitrification was achieved on the both of the condition. At the temperature of $35^{\circ}C$, nitrite conversion rate was better than $20^{\circ}C$. It can be concluded that treating the piggery wastewater using anaerobic digester on the condition of the temperature at $35^{\circ}C$ is more efficient on the nitritation of the piggery wastewater.

• 한국물환경학회지
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• 제27권3호
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• pp.286-292
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• 2011

Preparing for the Standards for Effluents which will be strengthen from 2012, many ways like remodellings and repairs of sewage treatment plant (STP) are considered. The treatment of the recycle water from the sludge treatment process contains high-strength organic compounds and nitrogen is considered as alternative. In the treatment of high-strength nitrogen, nitritation has more economic advantages than nitrification. In this study, lab-scale reactor was operated at the $35^{\circ}C$, $20^{\circ}C$ and $10^{\circ}C$ conditions using effluent of anaerobic digester to investigate the nitrogen removal by nitritation. Long-term stable nitritation was achieved at the $35^{\circ}C$, $20^{\circ}C$ but $10^{\circ}C$. In the stable nitritation states, nitrite conversion was higher at the high temperature of $35^{\circ}C$ than the room temperature of $20^{\circ}C$. Also shorter solid retention time (SRT) was needed to induce high nitrite conversion at the high temperature of $35^{\circ}C$. It was showed that temperature and SRT are important factors to induce nitritation.

• Journal of Ceramic Processing Research
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• 제13권spc2호
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• pp.308-311
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• 2012

A wide range of possible hazards existing in thermal batteries are mainly caused by thermal runaway, which results in overheating or explosion in extreme case. Battery separators ensure the separation between two electrodes and the retention of ion-conductive electrolytes. Thermal runaways in thermal batteries can be significantly reduced by the adoption of these separators. The high operating temperature and the violent reactivity in thermal batteries, however, have limited the introduction of conventional separators. As a substitute for separators, MgO powders have been mostly used as a binder to hold molten salt electrolyte. During recent decades the fabrication technology of ceramic fiber, which has excellent mechanical strength and chemical stability, has undergone significant improvement. In this study we adopted wet-laid nonwoven paper making method instead of the electrospinning method which is costly and troublesome to produce in volume. Polymeric precursor can readily be coated on the surface of wet-laid ceramic paper, and be formed into ceramic film after heat treatment. The mechanical strength and the thermo-chemical stability as well as the wetting behaviors of ceramic separators with various molten salts were investigated to be applicable to thermal batteries. Due to their excellent chemical, mechanical, and electrical properties, wet-laid nonwoven separators made from ceramic fibers have revealed positive possibility as new separators for thermal batteries which operate at high temperature with no conspicuous sign of a short circuit and corrosion.

• Macromolecular Research
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• 제17권10호
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• pp.763-769
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• 2009

A chromatographic method is used to measure interactions between dissimilar proteins in aqueous electrolyte solutions as a function of ionic strength, salt type, and pH. One protein is immobilized on the surface of the stationary phase, and the other is dissolved in electrolyte solution conditions flowing over that surface. The relative retention of proteins reflects the mean interactions between immobile and mobile proteins. The osmotic cross second virial coefficient calculated by assuming a proposed potential function shows that the interactions of unfavorable proteins depend on solution conditions, and the proposed model shows good agreement with the experimental data of the given systems.

• 상하수도학회지
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• 제13권4호
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• pp.27-34
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• 1999

An experimental study on improvement of the paper-mill wastewater treatment using the pure oxygen activated sludge process was conducted. The effects of hydraulic retention time(HRT) and BOD loading on organic removal efficiency were investigated. The BOD removal efficiencies were above 90% under all examined HRTs except for HRT of 3 hours. The increase of HRT from 3 hours to 6 hours, and to 12 hours significantly improved BOD and COD removal efficiencies, respectively. However, additional increase of HRT did not affect organic removal efficiency. F/M ratio change at fixed HRT did not affect organic removal efficiency. However, F/M ratio investigated in this study(0.11~1.98kgBOD/kgMLVSS/day) was 5 times greater in maximum than that of conventional activated sludge process, which implies that pure oxygen activated sludge process can treat wastewater with high organic strength. Under the same HRT, the volumetric BOD loading change cause no effect on organic removal efficiency also.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2001년도 추계학술발표논문집
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• pp.183-199
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• 2001

Alternative way of shaping fibers suitable for papermaking was introduced. Impact refining, which was done simply by hitting wet fibers with a metal weight vertically, was intended to keep the fibers from shortening and to cause mostly internal fibrillation. Virgin chemical pulp, its recycled one and OCC were used in the experiment. It was noticed from the experiment that impact refining on virgin chemical pulp kept the fiber length and Increased bonding properties greatly, However, in the recycled fibers from the chemical pulp, fiber length and bonding properties were decreased. In OCC, which seems to contain fractions of semi-chemical pulp and mechanical pulp (GP), and which is recycled pulp from corrugated boxes, fiber length and bonding properties were decreased disastrously. We believe recycled cellulosic fibers (recycled chemical pulp and OCC in this case), which went through hornification, were less resistant to the mechanical impact than virgin chemical pulp. For virgin chemical pulp, impact refining allowed no significant fiber length shortening, high WRV, and high mechanical strength.

• 펄프종이기술
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• 제34권4호
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• pp.1-6
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• 2002

In order to simulate the actual wet-end process in papermachine, RDA, a novel handsheet former, was used and following results were obtained. While the addition of polyelectrolytes gives significant effect on fiber flocculation, increase of stock consistency influenced on the formation of RDA sheets greatly. In particular, the consistency increase from 0.3 % to 0.4% abruptly increased floe size of RDA sheet and it results in severe deterioration of paper strength. Stock consistency, therefore, should be regarded as the most important factor in the formation simulation with RDA and should be controlled as the first sequence of tuning the operating conditions of RDA to simulate correctly the target machine paper's formation.