• Journal of Power System Engineering
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• v.5 no.1
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• pp.21-26
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• 2001

This paper represents the turbulent intensity, the turbulent kinetic energy and Reynolds shear stress in the X-Y plane of cone type swirl gas burner measured by using X-probe from the hot-wire anemometer system. The experiment is carried out at flowrate 350 and $450{\ell}/min$ respectively in the test section of subsonic wind tunnel. The turbulent intensity and the turbulent kinetic energy show that the maximum value is formed in the narrow slits distributed radially on the edge of a cone type swirl burner, hence, the combustion reaction is anticipated to occur actively near this region. And the turbulent intensities ${\upsilon}\;and\;{\omega}$ are disappeared faster than the turbulent intensity u due to the inclined flow velocity ejecting from the swirl vanes of a cone type baffle plate of burner. Moreover, the Reynolds shear stress $u{\upsilon}$ is distributed about three times as large as the Reynolds shear stress $u{\omega}$ in the outer region of the cone type gas burner.

• Journal of the Korean Geotechnical Society
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• v.26 no.7
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• pp.93-106
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• 2010

In performing a series of in-situ thermal response tests, the effective thermal conductivities of six vertical closed-loop ground heat exchangers were experimentally evaluated and compared one another, which were constructed in a test bed in Wonju. To compare thermal efficiency of the ground heat exchangers in field, the six boreholes were constructed with different construction conditions: grouting materials (cement vs. bentonite), different additives (silica sand vs. graphite) and the shape of pipe-sections (general U-loop type vs. 3 pipe-type). From the test results, it can be concluded that cement grouting has a higher effective thermal conductivity than bentonite grouting, and the efficiency of graphite better performs than silica sand as a thermally-enhancing addictive. In addition, a new 3 pipe-type heat exchanger provides less thermal interference between the inlet and outlet pipe than the conventional U-loop type heat exchanger, which results in superior thermal performance. Based on the results from the in-situ thermal response tests, a series of economic analyses have been made to show the applicability of the new addictives and 3 pipe-type heat exchanger.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.6
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• pp.360-366
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• 2000

This paper presents the fabrication and test of a micropump consisting of a pair of Al flap valves and a phase-change type actuator. The actuator is composed of a heater, a silicone rubber diaphragm and a working fluid chamber. The diaphragm is actuated by the vaporization and the condensation of the working fluid. The micropump is fabricated by the anisotropic etching, the boron diffusion and the metal evaporation. The forward and the backward flow characteristics of the flap valves illustrate the appropriateness as a check valve. Also, the flow rate of the micropump is measured. When the square wave input voltage of 8 V, 70% duty ratio and 2 Hz is applied to the heater, the maximum flow rate of the micropump is $97\muell/min$ for zero pressure difference.

• Nutrition Research and Practice
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• v.14 no.3
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• pp.286-297
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• 2020

BACKGROUND/OBJECTIVES: This study compared the perception of customers from Korea and the U.S. on the attributes of different formats of menu labeling The specific objectives were 1) to compare the customers' perceived usefulness, ease-of-understanding, clarity, and attractiveness of different formats of menu labeling between Korea and the U.S.; and 2) to compare the customers' use intention to different formats of menu labeling between Korea and the U.S. SUBJECTS/METHODS: A survey was conducted in Korea and the U.S. The participants were allocated randomly to view 1 of the 7 restaurant menus that varied according to the following types of menu labeling formats: (type 1) kcal format, (type 2) traffic-light format, (type 3) percent daily intake (%DI) format, (type 4) kcal + traffic-light format, (type 5) kcal + %DI format, (type 6) traffic-light + %DI format, and (type 7) kcal + traffic-light + %DI format. A total of 279 Koreans and 347 Americans were entered in the analysis. An independent t-test and 1-way analysis of variance were performed. RESULTS: Koreans rated type 4 format (kcal + traffic light) the highest for usefulness and attractiveness. In contrast, Americans rated type 7 (kcal + traffic light + %DI) the highest for usefulness, ease-of-understanding, attractiveness, and clarity. Significant differences were found in the customers' perceived attributes to menu labeling between Korea and the U.S. Americans perceived higher for all the 4 attributes of menu labeling than Koreans. CONCLUSIONS: The study is unique in identifying the differences in the attributes of different formats of menu labeling between Korea and the U.S. Americans rated the most complicated type of menu labeling as the highest perception for the attributes, and showed a higher use intention of menu labeling than Koreans. This study contributes to academia and industry for practicing menu labeling in different countries using different formats.

• Transactions of Materials Processing
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• v.13 no.8
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• pp.678-688
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• 2004

The U-draw bending operation is known as a representative test method for springback evaluation of sheet metals since the sheet in U-draw bending operation undergoes stretching, bending and unbending deformations occurred at the stamping process. In this study, a simplified approach was proposed for predicting springback and side-wall curls of tailor-welded blank in U-draw bending operations, using moment-curvature relationships derived for sheets undergoing stretching, bending and unbending deformation. Two different welded strips were adopted to compare the effects of weld-line locations on the springback. One (type A) was welded along the centerline of the strip-width and the other (type B) was welded along the centerline of the strip-length. To investigate the effect of different thickness combination on the springback, the tailor-welded strips were joined by the laser welding process and consisted of three types of thickness combinations of sheets, SCP1 0.8t ＊ SCP1 1.2t, SCP1 0.8t ＊ SCP1 1.6t and SCP1 0.8t ＊ TRIP 1.0t. Some calculated results by the simplified formula were compared with experimental results.

• Journal of the Korea institute for structural maintenance and inspection
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• v.2 no.2
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• pp.202-208
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• 1998

To investigae the effect of anchorage type of carbon fiber sheet (CFS) on flexural behavior of RC beams, the loading test of RC beams reinforced with CFS was conducted in variable of anchorage Type such as bolting anchorage and U type anchorage using CFS. This study can be summarized as follows ; It is confirmed experimentally that the bolting anchorage and U type anchorage with CFS is very effective to delay the bond failure and prevent the peeling of CFS. Also, the anchorage type applied with this study is very effective to improve the ductility compared with the improving of maximum flexural strength of RC beams. It is believed that the anchorage type used this study must secure the ductile capacity of above 3 for the flexural strengthening of RC beams. In the future, it is required to obtain the data about anchorage type of CFS for utilization of field work as well as investigate the ductile capacity of conventional study of anchorage type

• The Korea Journal of Herbology
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• v.38 no.2
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• pp.9-16
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• 2023

Objectives : Many people use natural soap instead of commercially available bar type general soap for skin care. They tend to prefer cp (cold process) type soaps that go through a sufficient maturation process in formulation. The purpose of this study was to investigate the efficacy of PCPS (placenta cp soap). Methods : The researcher selected 36 subjects, 28 as the experimental group and 8 as the control group. I asked participants to wash their face twice a day in the morning and evening, and the period was set for 6 weeks. The researcher had the people who were selected as the control group use a commercially available foam cleanser, meanwhile the experimental group use PCPS. They performed a skin test before the start of the test, and the change status was continuously investigated after 2 weeks, 4 weeks, and 6 weeks after using the soap. Results : In the case of U zone oil and pores, there was a significant decrease and in the case of skin tone, there was a significant increase in the group of using PCPS. In T zone oil change, there was no significant effect in both the experimental group and the control group. Conclusion : In the case of PCPS, it is recommended to use it in the effect of reducing the size of pores and increasing skin tone, but it can reduce u-zone oil content.

• Journal of the Korean Institute of Gas
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• v.5 no.3 s.15
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• pp.45-50
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• 2001

Open rack vaporizer (ORV) has been used in liquefied natural gas (LNG) receiving terminal in order to vaporize LNG into natural gas (NG) by heat exchange with seawater The U-type ORV which had been operated with seawater for 14 years is one of the important utilities of the gas production and the weld part of tube connected with header_ pipe had experienced many corrosion problems. To elucidate the cause of corrosion at weld part of vaporizer tube, corrosion potentials were compared by parts. This study concerns on the measurement of corrosion pit depth using non-destructive method and the evaluation of stress distribution in an aspect of safety with finite element analysis. In order to confirm the reliability of galvanic corrosion between weld parts and base metal, the measurement of corrosion potential by parts was conducted for 20 minutes in 3.5$\%$(wt.) NaCl solution. Many non-destructive methods were tried to measure the remaining thickness of vaporizer tube at fields. For general corrosion, tangential radiography test was confirmed as an effective method. In case of a fine corrosion pit, the shape of corrosion pit was reproduced using surface replication method. From collected data, stress distributions were quantitatively evaluated with 2-dimensional finite element method and the diagnostic evaluation on internal pressure of the U-type vaporizer could be made.

• Journal of the Korean Geotechnical Society
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• v.32 no.7
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• pp.5-14
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• 2016

The use of geothermal energy has increased for economically and environmentally friendly utilization, and a geothermal heat pump (GSHP) system for space heating and cooling is being used widely. As ground thermal properties such as ground thermal conductivity and ground thermal diffusivity are substantial parameters in the design of geothermal heat pump system, ground thermal conductivity should be obtained from in-situ thermal response test (TRT). This paper presents an experimental study of ground thermal properties of U and 2U type ground heat exchangers (GHEs) measured by TRTs. The U and 2U type GHEs were installed in a partially saturated dredged soil deposit, and TRTs were conducted for 48 hours. A method to derive the thermal diffusivity as well as thermal conductivity was proposed from a non-linear regression analysis. In addition, remolded soil samples from different layers were collected from the field, and soil specimens were reconstructed according to the field ground condition. Then equivalent ground thermal conductivity and ground thermal diffusivity were calculated from the lab test results and they were compared with the in-situ TRT results.

• The Korean Journal of Malacology
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• v.31 no.1
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• pp.61-67
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• 2015

The occurrence of 'algal bloom', caused by the mass proliferation of phytoplankton, causes serious problems in streams and lakes in Korea. Therefore, in this study, the phytoplankton filter-feeding trait of Unio douglasiae, a type of freshwater clam, was used to reduce the algal bloom in outdoor water tanks during the summer. This involved the construction of a U. douglasiae cultivation apparatus, wherein 1,000 clams were divided into 8 rectangular baskets arranged in the shape of an empty square. The control tank was manufactured in exactly the same shape within the water tank, but without the addition of clams. The algal bloom-reducing effect of U. douglasiae was confirmed by the measurement of (and comparing between) the water quality at the center and periphery of the test and control cultivation apparatus. Water quality measurements included the measurement of water temperature, pH, turbidity, dissolved oxygen (DO) content, and chlorophyll-${\alpha}$ concentrations; the water quality was measured twice a month between June and November 2014.The results of these analyses did not show a significant difference in water quality (temperature, pH, turbidity, DO) between the center and periphery of the test and control tanks. However, the chlorophyll-${\alpha}$ concentration was observed to be much lower at the center of the test tank compared to that at the center and periphery of the control tank, as well as at the periphery of the test tank. This was believed to be a result of the U. douglasiae surrounding the center of the test tank, which prevented the influx of plankton from the periphery. Accordingly, the results of these analyses suggest the possibility that U. douglasiae cultivation could reduce the proliferation of algal blooms in lakes and streams during the summer. In particular, these results indicate possible improvements in U. douglasiae activity (reduction in algal blooms) by their effective arrangement in the water bodies.