• Title/Summary/Keyword: Top cross test

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Experiments on the bearing capacity of tapered concrete filled double skin steel tubular (CFDST) stub columns

  • Ren, Qing-Xin;Hou, Chao;Lam, Dennis;Han, Lin-Hai
    • Steel and Composite Structures
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    • v.17 no.5
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    • pp.667-686
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    • 2014
  • Tapered concrete filled double skin steel tubular (CFDST) columns have been used in China for structures such as electricity transmission towers. In practice, the bearing capacity related to the connection details on the top of the column is not fully understood. In this paper, the experimental behaviour of tapered CFDST stub columns subjected to axial partial compression is reported, sixteen specimens with top endplate and ten specimens without top endplate were tested. The test parameters included: (1) tapered angle, (2) top endplate thickness, and (3) partial compression area ratio. Test results show that the tapered CFDST stub columns under axial partial compression behaved in a ductile manner. The axial partial compressive behaviour and the failure modes of the tapered CFDST stub columns were significantly influenced by the parameters investigated. Finally, a simple formula for predicting the cross-sectional capacity of the tapered CFDST sections under axial partial compression is proposed.

Experimental Investigation for Flexural Stiffness of Paperboard-stacked Structure

  • Lee, Myung-Hoon;Park, Jong-Min
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.7 no.1
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    • pp.9-15
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    • 2001
  • Top-to-bottom compression strength of corrugated fiberboard boxes is partly dependent on the load-carrying ability of the central panel areas. The ability of these central areas to resist bending under load will increase the stacking strength of the box. The difference of box compression strengths, among boxes which are made with identical dimensions and fabricated with same components but different flute sizes, is primarily due to difference of the flexural stiffness of the box panels. Top-to-bottom compression strength of a box is accurately predicted by flexural stiffness measurements and the edge crush test of the combined boards. This study was carried out to analyze the flexural stiffness, maximum bending force and maximum deflection for various corrugated fiberboards by experimental investigation. There were significant differences between the machine direction (MD) and the cross-machine direction (CD) of corrugated fiberboards tested. It was about 50% in SW and DW, and $62%{\sim}74%$ in dual-medium corrugated fiberboards(e.g. DM, DMA and DMB), respectively. There were no significant differences of maximum deflection in machine direction among the tested fiberboards but, in cross direction, DM showed the highest value and followed by SW, DMA, DMB and DW in order. For the corrugated fiberboards tested, flexural stiffness in machine direction is about $29%{\sim}48%$ larger than cross direction, and difference of flexural stiffness between the two direction is the lowest in DMA and DMB.

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An Experimental Study on Flexural Strength of Composite Beam with Reduced Top Flange of Steel (상부플랜지를 감소시킨 합성보의 휨내력에 관한 실험적 연구)

  • Moon, Chan-II;Jeong, Jae-Hun;Kim, Jin-Moo;Joo, Kyong-Jae
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.4 no.3
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    • pp.153-160
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    • 2000
  • In simply supported composite beams, the neutral axis of the composite cross section usually is located the top flange of the steel I-shape, so that the top flange does not impart much strength to the member. This suggests that omitting the top flange entirely could be a means to lower the cost of the beam without greatly reducing the strength. The purpose of this investigation is to research flexural strength and behavior of the composite beams with reduced top flange of steel. Five specimens with H and inverted T steel section were tested. As the test results, comparison of the experimental to computed full-plastic moment, and variations of flexural strength with reduced top flange were analyzed.

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Experimental Investigation for Flexural Stiffness of Paperboard-stacked Structure (종이성형구조물의 휨강성에 대한 실험적 연구)

  • Park, Jong-Min;Lee, Myung-Hoon
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.5 no.2
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    • pp.17-23
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    • 1999
  • Top-to-bottom compression strength of corrugated fiberboard boxes is partly dependent on the load-carrying ability of the central panel areas. The ability of these central areas to resist bending under load will increase the stacking strength of the box. The difference of box compression strengths, among boxes which are made with identical dimensions and fabricated with same components but different flute sizes, is primarily due to difference of the flexural stiffness of the box panels. Top-to-bottom compression strength of a box is accurately predicted by flexural stiffness measurements and the edge crush test of the combined boards. This study was rallied out to analyze the flexural stiffness, maximum bending force and maximum deflection for various corrugated fiber-boards by experimental investigation. There were significant differences between the machine direction (MD) and the cross-machine direction (CD) of corrugated fiberboards tested. It was about 50% in SW and DW, and $62%{\sim}74%$ in dual-medium corrugated fiberboards(e.g. DM, DMA and DMB), respectively. There were no significant differences of maximum deflection in machine direction among the tested fiberboards but, in cross direction, DM showed the highest value and followed by SW, DMA, DMB and DW in order. For the corrugated fiberboards tested, flexural stiffness in machine direction is about $29%{\sim}48%$ larger than cross direction, and difference of flexural stiffness between the two direction is the lowest in DMA and DMB.

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Characteristics and breeding of a new variety Cordyceps militaris 『Yedang 3』 (신품종 번데기동충하초 『예당 3호』 육성 및 특성)

  • Choi, Young-Sang;Kim, Hong-Kyu;Lee, Byung-Joo;Kim, Yong-Gyun
    • Journal of Mushroom
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    • v.7 no.4
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    • pp.182-186
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    • 2009
  • Single ascospores was isolated in Yesan-gun, Chungnam in 2006 with Cordyceps militaris. This study was carried out to select the superior isolates which produce more fruiting body and contain more cordycepin contents. Five single ascospore isolates were cultured on brown rice pupae medium and they formed fruiting bodies. To select better isolates, each isolates was hybridized and then the characteristics and cordycepin contents were investigated. After biological efficiency and codycepin contents were examined, finally C0601S05 was selected. Top-cross test of isolate C0601S05 was carried with 29 single ascospores. From this test, isolate C0601S05${\times}$C0601S33 and isolate C0601S05${\times}$C0601S43 containing highest cordycepin contents were selected. Codycepin contents of C0601S05 was 246mg% and those of C0601S05${\times}$C0601S33 and C0601S05${\times}$C0601S43 were 325mg% and 280mg%, respectively. C0601S05${\times}$C0601S33 was registered as Yedang 3 at the Korea seed & variety service.

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Characteristics of Droplet Properties in the Two-Phase Spray into a Subsonic Cross Flow

  • Lee, I.C.;Cho, W.J.;Koo, J.Y.
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.03a
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    • pp.358-363
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    • 2008
  • The spray cross-section characteristics of two-phase spray that using external-mixing nozzle injected into a subsonic cross flow were experimentally studied with various ALR ratio that is $0{\sim}59.4%$. Suction type wind tunnel was used and experiments were conducted to ambient environment. Several plain orifice nozzles with L/d of 30 and orifice diameter of 0.5 mm and orifice length 1.5 mm were tested. Free stream velocity profiles at the injection location were measured using hot wire. Spray images were captured to study collision point and column trajectory. Phase Doppler particle analyzer(PDPA) was utilized to quantitatively measuring droplet SMD, volume flux. Measuring probe of PDPA positions was moved 3-way transverse machine. SMD distributions were layered structure and peaked at the top of the spray plume and low value at bottom of the spray. Volume flux of spray was distributed to the two side region and volume flux quantity decreased when ALR ratio increased. It was found that the perpendicularly injected two-phase spray jet of external mixing into a cross flow showing that mistlike spray moved away from the test section bottom region.

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An Empirical Validation Study for Calibration Verification in TDM Test (검량보정 검증의 실험적 적합성에 대한 연구 -치료적 약물검사를 중심으로-)

  • Chang, Sang-Wu;Kim, Nam-Yong;Choi, Ho-Sung;Park, Yong-Won;Chu, Gyung-Bok;Yun, Keun-Young;Park, Byung-Ok
    • Korean Journal of Clinical Laboratory Science
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    • v.37 no.1
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    • pp.1-7
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    • 2005
  • The purpose of this study was to verify (i) a consistent calibration verification for the assessment of method linearity and (ii) calibration agreement with calibration settings. We validated calibration verification through method linearity with different lot number of individual calibrators that span the working range for 9 tests except salicylate with control sample in test. We evaluated that it covered broad analyte range to assay from near zero to the top of the measuring range with 5 or 6 points every three times for 10 analytes in TDM test. Target values were plotted on X-axis with assigned or observed values on the Y-axis. Working range were as follows. Calibration verification of the measuring range (maximum to minimum values) has been validated asetaminophen 0.1 to $304.6_{\mu}g/mL$, salicylate 0 to $1005_{\mu}g/mL$, valproic acid 3.2 to $154.19_{\mu}g/mL$, digoxin 0.17 to 5.65 ng/mL, vancomycine 1.3 to $80.51_{\mu}g/mL$, carbarmazepine 0.1 to $22.3_{\mu}g/mL$, phenytonin 0.6 to $40.21_{\mu}g/mL$, theophyline 0.2 to $40.21_{\mu}g/mL$, primidone 0 to $24.07_{\mu}g/mL$, phenobarbital 0.6 to $60.0_{\mu}g/mL$. Drawing a straight line through five or six points of these data showed good linearity. We are sure that it is important to assess the calibration verification of a test method to ascertain the lowest and highest test results that are reliable.

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Development of Short-span Precast Concrete Panels for Railway Bridge (철도교용 단지간 프리캐스트 콘크리트패널의 개발)

  • Seol, Dae-Ho;Lee, Kyoung-Chan;Kim, Ki-Hyun;Youn, Seok-Goo
    • Journal of the Korea Concrete Institute
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    • v.28 no.5
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    • pp.545-553
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    • 2016
  • This paper presents experimental static test results of the precast concrete panels developed for short-span concrete bridge deck form. Different from LB-DECK, concrete rib attached to the bottom surface of concrete panel, and Top-bar is not used at the top surface of concrete panel. Number of concrete ribs and cross-section details of concrete rib are determined from the analytical results of parametric study considering the span length and the thickness of concrete bridge decks. Shear rebars are installed at the top surface of concrete panel for composite action between precast concrete panel and cast-in-place concrete. In order to evaluate the safety and the serviceability of the developed short-span concrete panel subjected to design load, static load test is conducted. Three test panels with span length of 1.6m are fabricated, and during the load test displacements, strains and cracks of test panels are measured and final failure modes are investigated. Serviceability of the test panels is evaluated based on the results of displacements, cracking load, and crack width at the design load level. Safety is also evaluated based on the comparison of the ultimate strength and the factored design load of test panels. Based on the test results, it is confirmed the short-span precast concrete panel satisfies the serviceability and safety regulated in design codes. In addition, the range of span length of concrete bridge decks for the short-span concrete panel is discussed.

An experimental study of the mechanical performance of different types of girdling beams used to elevate bridges

  • Fangyuan Li;Wenhao Li;Peifeng Wu
    • Structural Engineering and Mechanics
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    • v.85 no.4
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    • pp.563-571
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    • 2023
  • Girdling underpinning joints are key areas of concern for the pier-cutting bridge-lifting process. In this study, five specimens of an underpinning joint were prepared by varying the cross-sectional shape of the respective column, the process used to treat the beam-column interface (BCI), and the casting process. These specimens were subsequently analyzed through static failure tests. The BCI was found to be the weakest area of the joint, and the specimens containing a BCI underwent punching shear failure. The top of the girdling beam (GB) was subjected to a circumferential tensile force during slippage failure. Compared to the specimens with a smooth BCI, the specimens subjected to chiseling exhibited more pronounced circumferential compression at the BCI, which in turn considerably increased the shear capacity of the BCI and the ductility of the structure. The GB for the specimens containing a column with a circular cross-section exhibited better shear mechanical properties than the GB of other specimens. The BCI in specimens containing a column with a circular cross-section was more ductile during failure than that in specimens containing a column with a square cross-section.

Healing Function Evaluation of Color Samples from the Healthcare Environmental Color Index - A Cross-cultural Comparison Study on Korean and Romanian users

  • Ardelean, Ioana;Oh, Jiyoung;Park, Heykyung
    • International Journal of Advanced Culture Technology
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    • v.9 no.3
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    • pp.131-141
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    • 2021
  • The present study is following a series of research investigations on design resources coming from collected data referring to users' awareness and preferences. The aim of this research is to test the Healthcare Environmental Color Index as a basis for practitioners in the field of healthcare design. An array of color samples selected from previous research, have been presented to the respondents via an online survey, in order to identify the preferences of the two groups on the relation between environmental color and health. As a result of the first experiment and through the comparison of processed data, the maximum percentage of respondents from each group is validating the relation between environmental color and health. For the second experiment we intend to highlight the patterns of color preferences for each group, and thus to test the color samples healing function. The compared data also showed a higher awareness of Koreans than Romanians on the potential of color applied to healing environment. Last but not least in the third experiment we show the top five color samples preferred by each group. It is significant that the comparison of the results validated once more some of our previous findings related to the healthcare environment, such as: the general preference for the green hue (associated to fatigue relax according to color psychology) and the blue hue (sedation release effect) but also the yellow hue - associated to bright energy. Three out of the top five preferred color samples have been identical to both groups while the other two samples have shown characteristic variations. These results show that similarities are strong and can be used in a glocal design strategy as an accessible tool for any practitioner. Based on the Healthcare Environmental Color Index and users' preferences analysis, a new design culture for healthcare can be established and developed.