• Journal of IKEEE
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• v.18 no.3
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• pp.420-426
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• 2014

In this paper, we have implemented the low temperature fluidity test system with the composited fuel filter and heater, which has tested the low temperature fluidity of gasoline, an engine start time, the consumption of electricity and power to evaluate the system performance. The test condition have used the diesel fuel, the normal temperature, the diesel fuel supply pressure $3.4kgf/cm^2$ at $-20{\sim}-30^{\circ}C$, the fuel supply quantization 60 l/H, the setting current 30 A and the voltage $13V_{dc}$. In order to simulate the operation of diesel fuel filter, we will establish the composited fuel filter into test jig, and be filled with chamber tank and filter by a constant flow quantization and pressure. After these, it shall be cold for setting time. And then we have measured the consumption current and power of heater, an operating time and pressure of filter.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.1
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• pp.18-24
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• 2013

Recently, the interest is increasing about the eco-friendly concrete. Accordingly, the blast furnace slag(BFS), a by-product of industry is known for improving the durability through compaction in concrete and is expanding the use. The research about BFS in concrete be accomplished frequently. In this study, we should know the hydration characteristic of BFS concrete the through the adiabatic temperature rise test due to the replacement of a variety of BFS. In addition, we produced the regression analysis factors through the test result and analyzied the effect for the replacement of BFS. According to test results, the compressive strength showed a slight degradation or equal and the the adiabatic temperature rise figure and rising factors are went down for rising replacment of BFS. In the future, the study about the adiabatic temperature rise equation for the various replacement of BFS and binder is considered necessary.

• Korean Chemical Engineering Research
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• v.43 no.6
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• pp.722-727
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• 2005

Dow99Ca350 (Dowex monosphere 99Ca/350 separation resin), MFG-220, and Finex CS-10GC are ion-exchange resins, and primarily used to separate sugars, and all of these resins have poly styrene DVB backbone, and sulfonyl group. These resins are already used to separate sugars continuously at sugar industry at constant temperature. These resins are used in experiments for understanding temperature effect on retention or adsorption behavior. Using Dow99Ca350, swelling test, porosity test, pulse test, and frontal analysis at various temperatures were performed. In the cases of MFG-220, and Finex CS-10GC, the effect of temperature variation was verified by pulse test. The experimental results are shown that Dow99Ca350, MFG-220, and Finex CS-10GC, which are commercial resins for sugar separation, are stable to temperature variation because the maximum change of retention time of fructose, and glucose are 1.76, and 3.37％ respectively.

• The Korean Journal of Pain
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• v.19 no.2
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• pp.159-163
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• 2006

Background: Despite the enormous amount of basic research on neuropathic pain, there is the lack of an objective diagnostic test for complex regional pain syndrome (CRPS). The aim of this study was to evaluate the usefulness of cold stress thermography in the diagnosis of CRPS. Methods: The study involved 12 patients with CRPS type 1, according to the IASP criteria, who were compared with 15 normal healthy volunteers. All subjects underwent thermographic examination under baseline conditions at $21^{\circ}C$. A cold stress test (CST; $10^{\circ}C$ water for 1 minute) was then applied to both hands below the wrists, immediate, and after 10 and 20 minutes. Results: The temperature asymmetry between the patients with CRPS and the volunteers showed significant discrimination at the baseline and after a 20 minute recovery period from the CST. Among the study subjects having temperature asymmetry of both hands of less than $1^{\circ}C$ (8 out of 12 CRPS patients and 14 out of 15 volunteer), 7 (87.5%) of the 8 CRPS patients and 3 (21%) of the 14 volunteers showed a temperature difference of more than $1^{\circ}C$ after the 20 minute recovery period. The actual temperature values during the four periods did not discriminate between the patients with CRPS and the volunteers. Conclusions: Thermography, under the CST, could be a more objective test for the diagnosis of CRPS. A temperature asymmetry greater than $1^{\circ}C$ during the 20 minute recovery period following CST provides strong diagnostic information about CRPS, with both high sensitivity and specificity.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.3
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• pp.253-258
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• 2016

The effect of temperature on the fracture energy, crack propagation, and crack tip opening displacement (CTOD) was determined for particulate reinforced composites using the wedge splitting test. The materials that were used consisted of a polymer binder, an oxidizing agent, and aluminum particles. The test rate of the wedge splitting specimen was 50 mm/min, the temperature conditions were $50^{\circ}C$, room temperature, $-40^{\circ}C$, and $-60^{\circ}C$. The fracture energy, calculated from splitting load-crack mouth opening displacement(CMOD) curves, increased with decreasing temperature from $50^{\circ}C$ to $-40^{\circ}C$. In addition, the strength of the particulate reinforced composites increased sharply at $-60^{\circ}C$, and the composites evidenced brittle fracture due to the glass transition temperature. The strain fields near the crack tip were analyzed using digital image correlation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.10
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• pp.1283-1288
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• 2012

A process heat exchanger (PHE) in a nuclear hydrogen system is a key component for transferring the considerable heat generated in a very high temperature reactor (VHTR) to a chemical reaction that yields a large quantity of hydrogen. A performance test on a medium-scale PHE prototype made of $Hastelloy^{(R)}$-X is scheduled in a small-scale gas loop at the Korea Atomic Energy Research Institute. In this study, as a preliminary study before carrying out the performance test in the gas loop, high-temperature structural analysis modeling and macroscopic thermal and structural analysis of the medium-scale PHE prototype by imposing the established displacement boundary constraints were carried out under the gas loop test condition. The results obtained in this study will be compared with the performance test results of the medium-scale PHE prototype in the gas loop.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.4
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• pp.133-140
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• 2010

The purpose of this study is to evaluate the new eco water tank which is made of high density polyethylene and concrete with low temperature cement. The strength and failure mode of eco water tank was examined through tensile test with mixture of concrete and HDPE, temperature monitoring for various kind of concrete, admixture contains etc. The strength and failure mode were examined through tensile test with mixture of concrete and HDPE, temperature monitering for different kinds of concrete, strength test with different admixtures etc. It was found that shear connector between concrete and HDPE effects significantly contributed to the combined structures. ㄱ type shear connector results in tensile strength of up to 40% compared to that of V type shear connector. Based on test result, the new eco composite tank improved the stability and safety the old one and demonstrated the applicability and capability.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.156-156
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• 2011

VPH (Volume Phase Hologram) grating is one of the transmission gratings and is known as its remarkable efficiency (>90%). It has two different densities of gelatins causing interference patterns. The VPH grating is favored in many astronomical instruments these days and also IGRINS, which is up coming near infrared high-resolution spectroscope expected to see the first light next year, uses the VPH grating as its cross-disperser. The infrared astronomical instruments operate at cryogenic temperature (~100K) in order to cut down thermal noise and the optical components of IGIRNS will be operated at 130K. The VPH grating is sandwiched in between fused silica or glass and glued together using optical adhesive. IGRINS is expected to go through 50 times of thermal cycling in 10 years including the performance test and this research is to check whether the physical characteristic such as the adhesion or dichromatic gelatin does not break and change from the several cryogenic thermal cycling. The two identical test gratings provided from Kaiser Optical System, Inc. are used in this test. One VPH grating is cooled down to 100K for 2 hours with maximum dT/dt = 5 and warmed up to the room temperature and another grating is kept stored in the room temperature and used as a control sample. In order to check the change, we inspected the grating with eyes and checked its efficiency and transmission at the room temperature every 10 cycling. From the 40 times of cryogenic temperature cool down cycling, the VPH grating showed no signs of change within the error compared to the control sample. We concluded the VPH grating is durable through several cryogenic thermal cycling.

• Corrosion Science and Technology
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• v.15 no.2
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• pp.84-91
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• 2016

The transport and deposition of corrosion products in pressurized water nuclear reactor (PWR) steam generators have led to corrosion (SCC, denting etc.) problems. Lancing, mechanical cleaning and chemical cleaning have been used to reduce these problems. The methods of lancing and mechanical cleaning have limitations in removing corrosion products due to the structure of steam generator tubes. But high temperature chemical cleaning (HTCC) with EDTA is the most effective method to remove corrosion products regardless of the structure. However, EDTA in chemical cleaning aqueous solution and chemical cleaning environments affects the integrity of materials used in steam generators. The nuclear power plants have to perform the pre-test (also called as qualification test (QT)) that confirms the effect on the integrity of materials after HTCC. This is one of the series studies that assess the effect, and this study determines the effects of 20 % EDTA aqueous solution on defective tubes in high temperature chemical cleaning environments. The depth and magnitude of defects in steam generator (SG) tubes were measured by eddy current test (ECT) signals. Surface analysis and magnitude of defects were performed by using SEM/EDS. Corrosion rate was assessed by weight loss of specimens. The ECT signals (potential and depth %) of defective tubes increased marginally. But the lengths of defects, oxides on the surface and weights of specimens did not change. The average corrosion rate of standard corrosion specimens was negligible. But the surfaces on specimens showed traces of etching. The depth of etching showed a range on the nanometer. After comprehensive evaluation of all the results, it is concluded that 20 % EDTA aqueous solution in high temperature chemical cleaning environments does not have a negative effect on defective tubes.

• The Journal of Advanced Prosthodontics
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• v.5 no.2
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• pp.133-139
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• 2013

PURPOSE. This study was to evaluate the effect of the solution temperature on the mechanical properties of dualcure resin cements. MATERIALS AND METHODS. For the study, five dual-cure resin cements were chosen and light cured. To evaluate the effect of temperature on the specimens, the light-cured specimens were immersed in deionized water at three different temperatures (4, 37 and $60^{\circ}C$) for 7 days. The control specimens were aged in a $37^{\circ}C$ dry and dark chamber for 24 hours. The mechanical properties of the light-cured specimens were evaluated using the Vickers hardness test, three-point bending test, and compression test, respectively. Both flexural and compressive properties were evaluated using a universal testing machine. The data were analyzed using a two way ANOVA with Tukey test to perform multiple comparisons (${\alpha}$=0.05). RESULTS. After immersion, the specimens showed significantly different microhardness, flexural, and compressive properties compared to the control case regardless of solution temperatures. Depending on the resin brand, the microhardness difference between the top and bottom surfaces ranged approximately 3.3-12.2%. Among the specimens, BisCem and Calibra showed the highest and lowest decrease of flexural strength, respectively. Also, Calibra and Multilink Automix showed the highest and lowest decrease of compressive strength, respectively compared to the control case. CONCLUSION. The examined dual-cure resin cements had compatible flexural and compressive properties with most methacrylate-based composite resins and the underlying dentin regardless of solution temperature. However, the effect of the solution temperature on the mechanical properties was not consistent and depended more on the resin brand.