• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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• pp.627-634
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• 1997

This is the Study on Application and Manufacture Technique of Cold-Mix, Cold-Laid type Asphalt Concrete using of Polymer modified asphalt the could be constructed easily and economically on damaged road repaireless for seasons. The modified materials for this study are SBS(Styrene-Butadiene-Styrene). SBR (Styrene-Butadiene-Rubber) and PUR(Polyurethane). The Marshall stability and the value of flow and resistance in water stability degree according to the alternation types and weight percent of modified materials were compared and evaluated on this study. The results of the study show that PUR modified asphalt have improvement of over 150% Marshall stability in AI MS-14 standard and they are evaluated to have the easiness of storage and better working efficiency compared with other types of modified asphalt compound.

• 한국정밀공학회지
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• 제21권9호
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• pp.142-148
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• 2004

It is already known that hardness number of cold-forged product is in close conjunction with its effective strain. This paper presents the method to predict the relation between effective strains and hardness by using FE-simulation of hardness test from the conception that hardness indicates resistance to plastic deformation. The results of FE-simulation for the materials are compared with those of experiments and also compared with those of experiments in reference to show the feasibility of the proposed method. In addition, the present method was applied to the cold-forged product to verify the relation between hardness and effective strain. As a result, the predicted hardness number by the present method is in good agreement with experimental values. Prediction of hardness fur a cold-forged product comes to be possible by estimating the relation between effective strain and hardness using the proposed method in this study.

• Nuclear Engineering and Technology
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• 제53권6호
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• pp.1909-1923
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• 2021

We experimentally investigated the effects of thermal aging and cold work on the microstructure, mechanical properties, and primary water stress corrosion cracking (PWSCC) initiation time for Alloy 182 welds. The effects of thermal aging and cold work on the PWSCC initiation time of Alloy 182 were modeled based on the plastic energy concept and the PWSCC initiation data of this study and previous reports by considering censored data. Based on the results, it is estimated that the PWSCC resistance of the Alloy 182 weld firstly increases and then decreases with thermal aging time when the applied stress is kept constant.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2002년도 춘계학술발표회 초록집
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• pp.39-39
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• 2002

In order to improve wear and fatigue resistance of the structural materials, especially cold work roller for 304 stainless steel, an eco-super-finishing and surface hardening treatment using ultrasonic vibration energy was developed and applied to the SKD-ll roller. The eco-super-finishing machine was designed and fabricated by DesignMecha Co, by its own technology. It was observed that the surface roughness, hardness and residual stress were changed from $Ra{\;}={\;}O.25\mu\textrm{m}$, Hv=710 and ${\sigma}$={\;}+400{\;}MPa{\;}to{\;}Ra{\;}={\;}0.165\mu\textrm{m}$, Hv = 1200 and ${\sigma}=-610$ MPa after 20 KHz micro-cold forging, which means almost equal to the 300 % improvement of life-time.

• 한국표면공학회지
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• 제28권5호
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• pp.289-299
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• 1995

The effects of phosphate coating have been studied on physical properties and corrosion resistance of painted aluminum alloy sheet for automobile body. The physical properties (surface roughness, paint adhesion, impact resistance and pencil hardness) and corrosion resistance(cyclic corrosion and filiform corrosion) were investigated. Phosphate coatings enhanced the physical properties of painted Al alloy sheet, especially paint adhesion after the 240hours water immersion test. Phosphate coating also markedly improved the resistance for cyclic corrosion and filiform corrosion of painted cold rolled steel and Zn-Ni plated steel sheet as well as painted Al alloy sheet. The corrosion resistance of painted Al sheets was varied with the concentration of free fluoride ion and metal additives like Ni and Mn in the phosphating bath. A maximum corrosion resistance was obtained at about 300ppm of fluoride ion and additives of Ni and Mn obviously increased the corrosion resistance of painted specimens.

• 생약학회지
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• 제5권4호
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• pp.217-222
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• 1974

Oxygen consumption rate has been determined to study the effect of 'Gal Geun Tang' upon stress resistance of rats. The oxygen consumption rate of liver tissue increased slightly when normal rats were given the Gal Geun Tang infusion only. When rats were given the infusion after an injection of typhoid vaccine, the elevated boby temperature and oxygen consumption rate due to typhoid vaccine fell to normal level. From this result, it is concluded that 'Gal Geun Tang' has a function that may normalize abnormally strained liver metabolism. Oxygen consumption rate of the rats significantly increased when rats were exposed to cold condition. However, under the same condition it rather maintained the normal consumption rate when the rats were given previously "Gal Geun Tang". It is suggested that 'Gal Geun Tang' has an effects that impairs the immune response from cold stress. The rats that were given Cinnamomi Ramulus('Ge Ji Tang') showed less effect than the group of 'Gal Geun Tang'.

• 한국초전도ㆍ저온공학회논문지
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• 제15권4호
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• pp.59-62
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• 2013

The conductive link is used as a cooling medium between a cryocooler and magnet in a cryogen-free superconducting magnet system. The low temperature superconducting (LTS) magnet has one solenoidal configuration with a metal former which has a 52 mm room temperature bore. The superconducting coil is installed in the cryostat maintaining high vacuum and cooled by a two-stage cryocooler. In order to maintain the operating temperature of magnet at the designed level, the cold head temperature of the cryocooler must be lower so that heat can be removed from the superconducting coil. Also, temperature difference is occurred between the magnet and cryocooler and its magnitude is dependent upon the contact resistance at the interfacial surface between metals in the conductive link. In the paper, the performance of the LTS magnet is investigated with respect to the conductive link between the magnet former and the cold head of the cryocooler. The effects of the contact pressure and interfacial materials on the temperature distribution along the conductive link are also presented.

• 한국초지조사료학회지
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• 제7권3호
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• pp.135-139
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• 1987

The influence of ploidy level on agronomic characteristics in italian ryegrass, Lolium multiflorum Lam, italicum, was studied using diploids (2x) and tetraploids (4x) on the upland of Livestock Experiment Station, Suweon. The results are summarized as follow: 1. Tetraploid cultivars are in general dark green in leaf color and strong glittered. 2. Diploid cultivars are more resistant to cold than tetraploids but degree of resistance to cold depends on cultivars. The di-and tetraploids did not differ in summer survival and coldand heat resistance of di-Itetraploid cultivars were not related. 3. Tetraploid cultivars have larger leaf-blades, more rapid growth and higher leaf ratio to stem by heading than diploids. 4. Tetraploids possess significantly lower dry matter content than diploids. 5 . Fresh- and dry weight of tetraploids are similar with that of diploids but tetraploids are more leafy than diploids. 6. Seasonal yield depends more on the type of the cultivar than on its tetraploid nature.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2007년 추계학술발표대회 개요집
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• pp.342-344
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• 2007

The resistance spot weldability of surface textured cold-rolled steel sheet was evaluated. One steel sheet(T4.5) showed reduced electrode life with less than 2000 welds, and all other steel sheets(E2.2, E4.5, T2.2) made more than 2500 welds. The carbon imprint test revealed that there is sudden electrode diameter increase around 1700 welds. It is believed that the increased electrode diameter decreased current density, and resulted in decreasing weld electrode life due to small weld button size. It is considered that surface roughness difference may attribute to heating during weld cycle and reduced the weld electrode life.

• International Journal of Korean Welding Society
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• 제2권1호
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• pp.52-56
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• 2002

This report was prepared to give informations on a proper way to develop new consumables for the steels with improved weldability. Traditionally, hydrogen control has been pursued mainly for suppressing the HICC in HAZ but it also has contributed to HICC in weld metal. Facing the limitations in reducing the hydrogen content, it is now important to consider the microstructural control approach in order to improve the HICC resistance of weld metal . It has been shown that changes in alloy design, and hence composition and microstructure, was quite effective in producing high strength weld metal with improved resistance to cold cracking. Besides the economic test methods for evaluating susceptibility of multipass weld metal is essential to promote the development of welding consumables.