• Title/Summary/Keyword: Pack test

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Skin Friction Mobilized on Pack Micropiles Subjected to Uplift Force (인발력을 받는 팩마이크로파일의 주면마찰력)

  • Hong, Won-Pyo;Cho, Sam-Deok;Choi, Chang-Ho;Lee, Choong-Min
    • Journal of the Korean Geotechnical Society
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    • v.28 no.6
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    • pp.19-29
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    • 2012
  • Pack micropiles were recently developed to improve pile capacity of general micropiles. Pack micropiles were made by warping thread bar or steel pipe of general micropile by geotexlile pack and grouting inside the pack with pressure. According to the pressure, the boring hole could be enlarged. A series of pile uplift tests were performed on three micropiles. Two out of the three piles were the pack micropiles and the other was the general micropile, in which a thread bar was used in the boring hole. According to the pressure applied to the pack micropiles, the diameter of boring hole was enlarged from 152 mm to 220 mm. Unit skin friction mobilized on side surfaces of micropiles increased with displacement of pile head and reached on a constant value, which represents that the relative displacement between piles (or thread bar) and soils was reached on critical state. And the uplift resistance of pack micropile was higher than that of general micropile. Two reasons can be considered: One is that the frictional surface increases due to enlarging diameter of boring holes and the other is that the unit skin friction could increase due to compressing effect of surrounding soils by soil displacement as much as the enlarging volume of boring hole. The compression effect appeared at deeper layer rather than surface layer. The unit skin friction mobilized on micropiles with small diameter was higher than the ones on large bored piles.

Study on Resistance Performance of Icebreaking Cargo Vessel in Pack Ice Condition according to Variation of Synthetic Ice Thickness and Hull Form Characteristics (합성얼음의 두께변화와 선형변화에 따른 Pack ice 상태에서의 쇄빙상선의 저항특성 연구)

  • Lee, Seung-Ho;Kim, Moon-Chan;Chun, Ho-Hwan;Cho, Jun-Cheol;Shin, Byung-Chul;Jung, Un-Hwa
    • Journal of the Society of Naval Architects of Korea
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    • v.46 no.5
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    • pp.471-478
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    • 2009
  • The present paper deals with characteristics of resistance performance according to the variation of synthetic ice thickness and hull form. The resistance test has been conducted with pack ice condition in Pusan National University towing tank. Stem angle has been chosen as main parameters for the variation of hull form characteristics, which is the most important factor especially in icebreaking cargo vessel. The serial comparisons of resistance test have been done with the variation of hull form parameter as well as with the different thickness of synthetic ice. The different trend of resistance performances with increasing of stem angle has been shown at each synthetic ice thickness. The present test results is expected to be confirmed by comparing the test results in ice tank in the near future.

A STUDY ON THE PHYSICAL PROPERTIES AND VOLUMETRIC STABILITY OF SR-IVOCAP RESIN SYSTEM (SR-Ivocap resin system의 물리적 특성과 체적 안정성에 관한 연구)

  • Eun, Sung-Sik;Kweon, Hyeog-Sin;Chung, Chae-Heon
    • The Journal of Korean Academy of Prosthodontics
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    • v.36 no.3
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    • pp.453-467
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    • 1998
  • This study helps to clarify conflicting reports by comparing the physical properties and accuracy of complete denture processed by the pack and press technique, continuous- pressure injection technique(SR-Ivocap system) and Mark press technique. The 6 different specimens have been evaluated using the SEM, Impact test, DSC (Differential Scanning Calorimetry) and DMTA (Dynamic Mechanical Thermal Analysis). Each sample was made of SR-Ivocap resin and QC-20 resin by different processing methods. The results were as follows ; 1. As the result of the observation on the fracture surface of resin by use of SEM, sample SR-Ivocap resin cured by continuous pressure injection method showed the most homogeneous structure. This is why molecules in SR-Ivocap resin have no orientation. 2. As the result of the Impact test in order to measure the deformity, fracture energy and impact resistance of resin, the samples with QC-20 acrylic resin and SR-Ivocap resin cured by continuous pressure injection method were exellent. 3. In consequence of measuring ${\alpha}$-glass transition temperature by use of DSC on the basis of temperature change, the glass transition temperatures of sample QC-20 resin cured by pack and press method and sample SR-Ivocap resin cured by continuous pressure injection method were very similar. Thus volumetric stability could not be evaluated only by glass transition temperature. 4. In comparing volumetric stability data by DMTA, the glass transition temperature(Tg) showed $137.88^{\circ}C$ at sample QC-20 resin cured by pack and press method and $139.78^{\circ}C$ at sample SR-Ivocap resin cured by continuous pressure injection method. Therefore sample SR-Ivocap resin cured by continuous pressure injection method seems to be superior to sample QC-20 resin cured by pack and press method in the dimensional stability at high temperature. 5. In comparing storage modulus data by DMTA, the storage modulus of sample SR-Ivocap resin cured by continuous pressure injection method was higher than that of sample QC-20 resin cured by pack and press method. So. sample SR-Ivocap resin cured by continuous pressure injection method seems to be superior to sample QC-20 resin cured by pack and press method in impact strength.

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A Study on the Usefulness of Development of a Steam Sterilizer Equipped with an Electronic Bowie-Dick Test System

  • Bae, Young Ok;Hwang, Jun Soo;Kim, Sung Il;Lee, Joon Ha
    • Progress in Medical Physics
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    • v.28 no.4
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    • pp.156-163
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    • 2017
  • To verify the usefulness of a steam sterilizer equipped with an electronic Bowie-Dick test system, this study was carried out using two methods, utilizing both a steam sterilizer and an electronic Bowie-Dick tester. The first method is to confirm the error detection of the chemical Bowie-Dick test pack and the electronic Bowie-Dick tester in a malfunctioning sterilizer environment. For this purpose, the Bowie-Dick test program for the steam sterilizer was used to test three types of test packs commonly used in hospitals and the electronic Bowie-Dick tester by changing the set values of temperature, time, and vacuum frequency. The second is an experiment to check the sterilizer's normal operation with the electronic Bowie-Dick tester and the usefulness of grasping the cause of the malfunction. The results showed that the sterilization temperature was the same as that of the test pack at a temperature $1{\sim}6^{\circ}C$ lower than the reference temperature of $134^{\circ}C$. In the test with the sterilization exposure time as a variable, there was a normal discoloration at a time difference of 30~90 s. In the experiment using the number of vacuum cycles, the test was correct by performing the normal discoloration only at the normal condition of 3 times. The test results of 30 hospitals were 100 failure tests by a total of 291 Bowie-Dick tests. Of these, the failure factors related to an internal temperature that the chemical test packs could not detect were the greatest, and the four factors related to temperature, including the internal temperature, were found to be 71.18% of total malfunctions. In addition, the Bowie-Dick tester was provided within 30 min after the start of the Bowie-Dick test to confirm the performance of the sterilizer and the detailed cause. A steam sterilizer equipped with an electronic Bowie-Dick test system is used to manage individual sterilizers. In the current steam sterilizer with many temperature-related errors, it is possible to check the malfunction of the temperature difference that the test pack cannot detect, and the cause of error for the sterilizer is immediately detected after the test. The steam sterilizer equipped with the electronic Bowie-Dick test system assists with infection control with accurate sterilizer performance assurance.

Development of High-Performance Smart Battery for Notebook PCs with Lithium Ion Battery (리튬이온전지를 이용한 노트북 PC용 고성능 Smart Battery의 개발)

  • 김현수;문성인;윤문수;고병희;김동훈
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.11
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    • pp.1047-1054
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    • 2003
  • Smart battery pack (SBP) for notebook PCs was developed using a cylindrical-type lithium ion battery. Batteries were connected with three serial and two parallel, the nominal capacity and the maximum load of SBP was 4,000mAh and 4.0A, respectively. The SBP was composed of a protection IC, by which safety of lithium ion batteries is maintained against overcharge, overdischarge and overcurrent, and a smart IC, which calculates the remaining capacity and the remaining run time. In matching test on notebook PC using Battery Mark 4.0, real and smart data of END voltage coincided nearly and LB and LLB signal worked norma]]y. And there were errors of less than 1% between the real and the smart data on the residual capacity in the charge and discharge test.

The Influence of Various Carrying a Pack Methods during Walking on Parameters of Foot Contact (가방 휴대 방법이 보행 시 발바닥 접촉 양상에 미치는 영향)

  • Park, Soo-Jin;Kwon, Yoo-Jung;Kim, Min-Hee;Kim, Jin-Sang
    • Journal of Korean Physical Therapy Science
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    • v.18 no.2
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    • pp.29-40
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    • 2011
  • Purpose: The purpose of this study was to analyze the changes of parameters of foot contact by various carrying a pack methods during walking. Method: The subjects were consisted of normal forty four persons (males 30, females 14, mean age 23). The carrying a pack methods were classified into five conditions: carrying no bag(Con 1), carrying a backpack(Con 2), carrying a shoulder bag(Con 3), carrying a cross bag(Con 4), carrying a one-hand bag(Con 5). All subjects were participated in these five condition and measured foot pressure by F-scan system during walking. Then foot contact time, foot contact area, foot contact length and width were measured and analyzed. The repeated one-way analysis of variance (ANOVA) was used to get difference between conditions and independent t-test was used to get difference between left and right foot within condition. Result: In the comparison of parameters of foot, contact time, contact area and mid foot width were significantly different between conditions(p<.05), and in both foot contact time at condition 5 showed the most significant reduction(p<.05). In the comparison of parameters of foot between left and right foot within condition, every conditions were not significantly different(p>.05). Conclusion: In this study various carrying methods changed the parameters of foot contact and showed significant difference in some articles between carrying methods. However, asymmetric load of pack by carrying methods didn't affected symmetry of parameters of foot contact between left and right foot.

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The Report on Test Results of CO Fire Extinguishing System ($CO_2$ 소화설비 구성부품 성능시험보고)

  • Kim, Gi-Ok;Lee, Chan-Ju;An, Byeong-Ho
    • Fire Protection Technology
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    • s.14
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    • pp.5-12
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    • 1993
  • This report is explained about test results of carbon dioxide extinguiching system components and pack-age type system (Kits) for automatic fire extinguishing system. A carbon dioxide system may be used to protect one or more hazards or hazards by menas of directional valves. Package system shall be installed to protect hazards within the limitations. The testing program was progressed by three items, external oppearance test, performance test and Total Flooding Fire Extinguishing System test. The object of this report is present the problem which apperar from the analysis of test results.

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Comparison Study on the Resistance Characteristics of an Arctic Tanker and a General Tanker (쇄빙 유조선과 일반 유조선의 저항특성 비교연구)

  • Kim, Hyun-Soo;Ha, Mun-Keun;Ahn, Dang;Chun, Ho-Hwan
    • Journal of the Society of Naval Architects of Korea
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    • v.43 no.1 s.145
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    • pp.43-49
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    • 2006
  • The hull form of icebreaking tanker depends on the trade route and ice characteristic. The hull form has to be designed for icebreaking concept if the vessel is operating in heavy ice and also the hull from has to be optimized for general tanker when the ship is operating in ice-free ocean. This paper presents comparison of ship resistance in pack ice, level ice and open water. Four ships are used to compare the resistance characteristic. One is conventional tanker and three ships are icebreaking tankers. The ice model test was carried out at the IOT (Institute for Ocean Technology, Newfoundland, Canada) and open water test was performed at 55MB (Samsung Ship Model Basin). The ice resistance of conventional tanker was predicted by Colbourne's method. The resistance of open water, pack ice and level ice are compared and discussed. The best hull form of icebreaker is not good in open water performance compare to conventional tanker. This result explains that the hull form of icebreaker and normal tanker have to compromise when the ship is operated in ice and ice-free condition. The result of this paper gives a guide for icebreaking tanker design.

Comparative Study on Resistance Performance of Icebreaking Cargo Vessel according to Hull Form Variation by using Synthetic Ice and Refrigerated Ice (합성얼음과 냉동얼음을 이용한 선형을 변화시킨 쇄빙상선의 저항특성 연구)

  • Lee, Seung-Ho;Kim, Moon-Chan;Chun, Ho-Hwan;Shin, Byung-Chul
    • Journal of the Society of Naval Architects of Korea
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    • v.47 no.3
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    • pp.350-358
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    • 2010
  • The present paper deals with the comparative study of resistance performance with refrigerated ice and synthetic ice according to the variation of hull form characteristics. The resistance test has been conducted in pack ice condition in each concentration condition. Stem angle has been chosen as main parameters for the variation of hull form characteristics. The correlation of performance between with the refrigerated ice and with the synthetic ice has been shown according to the variation for stem angles. The present study show the possibility of ice test in general towing tank with synthetic ice for the time-consuming research such as hull form optimization although that is confined in pack ice condition. The more parametric study for the properties of synthetic ice is expected to be conducted to have more close correspondence for the test results of refrigerated ice in near future.

Verification Studies for Field Peformance of Micropiling (성능검증을 위한 마이크로파일 현장 시험시공 및 재하시험)

  • Goo, Jeong-Min;Lee, Ki-Hwan;Cho, Young-Jun;Choi, Chang-Ho
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.368-375
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    • 2009
  • This paper describes field installation and load test results performed for three types of micropiles in the process of developing a new micropiling method. Field tests were performed for two conventional types(i.e., micropile reinforced with steel bar and gravity grouting, micropile reinforced with steel bar and steel casing and gravity grouting) and a proposed type(i.e., micropile reinforced with hollow steel pipe wrapped with geotextile-pack and pressurized grouting). The load test results subjected to axial compression and tension and lateral loading conditions are described in this paper. The micropiles were exposed in the air in order to verify the installation quality and curing condition of grouting material via ground excavation. Axial compression and tension test results indicate that the new micropile type provide at least 40% higher bearing capacity than that of conventional types. Based on the examination of exposed piles, it is induced that the proposed method, packed micropile, provides better interlocking between grouts and surrounding soils and increases higher frictional resistance comparing to conventional types.

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