• Title/Summary/Keyword: column effect

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Separation of Follicular Fluid Components Stimulating Sperm Migration with Chromatographic Paper, $=mu$RPC and Superose Columns (Chromatography용 Paper, $\mu$RPC Column 및 Superose Column을 이용한 정자의 이동을 자극하는 난포액 성분의 분리)

  • 박영식
    • Journal of Embryo Transfer
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    • v.13 no.3
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    • pp.301-312
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    • 1998
  • To efficiently separate a protein stimulating sperm swim-up migration and movement from follicular proteins, the effect of paper chromatography and liquid chromatography with reverse phase column and superose column on protein separation was examined. And the results obtained were as follows; 1. The band component that was separated with paper chromatography stimulated sperm migration and movement depending on its additional levels. Especially, band I component significantly increased sperm migration. But, all components of bands 1, 2 and 3 showed lower sperm migration and movement, compared to follicular fluid at the same additional level. 2. Among the components separated from follicular protein of 2~5mm follicles with reverse phase column ($\mu$RPC), components at retention time (RT) of 3.33, 7.00, 13.87, and 16.6A minutes stimulated sperm migration within a limited range. 3. All components separated from follicular protein of 10mm follicles with $\mu$RPC column didn't stimulate sperm migration and movement. 4. Among the components separated from follicular protein of 2~5m follicles with superose column, components at retention volume (RV) of 1.35 and 0.82 ml significantly stimulated sperm migration and movement. In conclusion, protein components stimulating sperm migration and movement were efficiently separated with superose column in Smart system. Especially, components of RV 1.35 and RV0.82 stimulated sperm swim-up separation.

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Effective Length of Reinforced Concrete Columns in Braced Frames

  • Tikka, Timo K.;Mirza, S. Ali
    • International Journal of Concrete Structures and Materials
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    • v.8 no.2
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    • pp.99-116
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    • 2014
  • The American Concrete Institute (ACI) 318-11 permits the use of the moment magnifier method for computing the design ultimate strength of slender reinforced concrete columns that are part of braced frames. This computed strength is influenced by the column effective length factor K, the equivalent uniform bending moment diagram factor $C_m$ and the effective flexural stiffness EI among other factors. For this study, 2,960 simple braced frames subjected to short-term loads were simulated to investigate the effect of using different methods of calculating the effective length factor K when computing the strength of columns in these frames. The theoretically computed column ultimate strengths were compared to the ultimate strengths of the same columns computed from the ACI moment magnifier method using different combinations of equations for K and EI. This study shows that for computing the column ultimate strength, the current practice of using the Jackson-Moreland Alignment Chart is the most accurate method for determining the effective length factor. The study also shows that for computing the column ultimate strength, the accuracy of the moment magnifier method can be further improved by replacing the current ACI equation for EI with a nonlinear equation for EI that includes variables affecting the column stiffness and proposed in an earlier investigation.

Progressive collapse analysis of stainless steel composite frames with beam-to-column endplate connections

  • Wang, Jia;Uy, Brian;Li, Dongxu;Song, Yuchen
    • Steel and Composite Structures
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    • v.36 no.4
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    • pp.427-446
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    • 2020
  • This paper carries out the progressive collapse analysis of stainless steel composite beam-to-column joint sub-models and moment-resisting frames under column removal scenarios. The static flexural response of composite joint sub-models with damaged columns was initially explored via finite element methods, which was validated by independent experimental results and discussed in terms of moment-rotation relationships, plastic hinge behaviour and catenary actions. Simplified finite element methods were then proposed and applied to the frame analysis which aimed to elaborate the progressive collapse response at the frame level. Nonlinear static and dynamic analysis were employed to evaluate the dynamic increase factor (DIF) for stainless steel composite frames. The results suggest that the catenary action effect plays an important role in preventing the damaged structure from dramatic collapse. The beam-to-column joints could be critical components that influence the capacity of composite frames and dominate the determination of dynamic increase factor. The current design guidance is non-conservative to provide proper DIF for stainless steel composite frames, and thus new DIF curves are expected to be proposed.

Effect of Light Metal Ions and Competition among Heavy Metal Ions during the Adsorption of Heavy Metal Ions by Bark (수피에 의한 중금속 흡착시 경금속의 영향과 중금속간의 흡착 경쟁)

  • Paik, Ki-Hyon;Kim, Dong-Ho;Choi, Don-Ha
    • Korean Journal of Environmental Agriculture
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    • v.16 no.2
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    • pp.115-118
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    • 1997
  • When the light metals such as $Ca^{++}$ and $Mg^{++}$ were added to heavy metal solution, the adsorption of heavy metals was increased by 20 to 30% more, but there were no differences between species. $Pb^{++}$ was the most adsorbed metal(99.5%), and the adsorption ratio of $Cd^{++}$ was significantly improved. In addition, when the light metal concentration was increased to 100ppm, the adsoption ratios of all four heavy metals were reached to 92 to 99%, while coniferous barks showed only 85 to 92%. On the mixture of four heavy metals, the adsorbed amount of each metal was significantly reduced, compared with that of one heavy metal, while $Zn^{++}$ showed the adsorption improvement to 95%. On the column experiment, $Pb^{++}$ was almost completely adsorbed in the upper part of column, and the adsorbed amount of $Cu^{++}$ was gradually decreased depending on column depth. However, $Cd^{++}$ and $Zn^{++}$ were not influenced by column height, and constantly adsorbed on various column height. Based on the above results, each heavy metal had different adsorption mechanism.

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A study on pushover analyses of reinforced concrete columns

  • Sung, Yu-Chi;Liu, Kuang-Yen;Su, Chin-Kuo;Tsai, I-Chau;Chang, Kuo-Chun
    • Structural Engineering and Mechanics
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    • v.21 no.1
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    • pp.35-52
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    • 2005
  • This paper proposes a realistic approach to pushover analyses of reinforced concrete (RC) structures with single column type and frame type. The characteristic of plastic hinge of a single RC column subjected to fixed axial load was determined first according to column's three distinct failure modes which were often observed in the experiments or earthquakes. By using the determined characteristic of plastic hinge, the pushover analyses of single RC columns were performed and the analytical results were investigated to be significantly consistent with those of cyclic loading tests. Furthermore, a simplified methodology considering the effect of the variation of axial force for each RC column of the frame structure during pushover process is proposed for the first time. It would be helpful in performing pushover analysis for the structures examined in this study with efficiency as well as accuracy.

Concrete columns reinforced with Zinc Oxide nanoparticles subjected to electric field: buckling analysis

  • Arbabi, Amir;Kolahchi, Reza;Bidgoli, Mahmood Rabani
    • Wind and Structures
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    • v.24 no.5
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    • pp.431-446
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    • 2017
  • As concrete is most usable material in construction industry it's been required to improve its quality. Nowadays, nanotechnology offers the possibility of great advances in construction. In this study, buckling of horizontal concrete columns reinforced with Zinc Oxide (ZnO) nanoparticles is analyzed. Due to the presence of ZnO nanoparticles which have piezoelectric properties, the structure is subjected to electric field for intelligent control. The Column is located in foundation with vertical springs and shear modulus constants. Sinusoidal shear deformation beam theory (SSDBT) is applied to model the structure mathematically. Micro-electro-mechanic model is utilized for obtaining the equivalent properties of system. Using the nonlinear stress-strain relation, energy method and Hamilton's principal, the motion equations are derived. The buckling load of the column is calculated by Difference quadrature method (DQM). The aim of this study is presenting a mathematical model to obtain the buckling load of structure as well as investigating the effect of nanotechnology and electric filed on the buckling behavior of structure. The results indicate that the negative external voltage applied to the structure, increases the stiffness and the buckling load of column. In addition, reinforcing the structure by ZnO nanoparticles, the buckling load of column is increased.

Effect of Anchorage on Strength of Precast R/C Beam-Column Joints

  • Kim, Kwangyeon
    • Architectural research
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    • v.2 no.1
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    • pp.55-60
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    • 2000
  • Recently, there is a great demand for precast reinforced concrete (RC) construction methods on the purpose of simplicity in construction. Nishimatsu Construction Company has developed a construction method with precast reinforced concrete members in medium-rise building. In this construction method, how to joint precast members, especially the anchorage of the main bar of beam, is important problem. In this study, the structural performance of exterior joints with precast members was investigated. The parameters of the test specimens are anchorage type of the main bar of beam (U-shape anchorage or anchorage plate) and the ratio of the column axial force to the column strength. Specimens J-3 and J-4 used U-shape anchorage and the ratio of the column axial force of specimen J-4 was higher. On the other hand, specimens J-5 and J-6 used anchorage plate, and the anchorage lengths are 15d and 18d, respectively. Experimental results are summarized as follows; 1) For the joints with beam flexural failure mode, it was found that the maximum strength of specimen with anchorage plate is equal to or larger than that of specimen with conventional U-shaped anchorage if the anchorage length of more than 15d would be ensured, 2) Each specimen shows stable hysteretic curves and there were no notable effects on the hysteretic characteristics and the maximum strength caused by the anchorage method of beam main bar and the difference of column axial stress level.

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Immobilized Small Sized Manganese Dioxide Sand in the Remediation of Arsenic Contaminated Water

  • Tiwari, Diwakar;Laldawngliana, C.;Lee, Seung-Mok
    • Environmental Engineering Research
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    • v.19 no.1
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    • pp.107-113
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    • 2014
  • Small sized manganese dioxide particles are immobilized onto the surface of sand by the wet impregnation process. The surface morphology of the solid, i.e., immobilized manganese dioxide natural sand (IMNS) is performed by taking scanning electron microscope images and characterized by the X-ray diffraction data. The specific surface area of the solid is obtained, which shows a significant increase in the specific surface area obtained by the immobilization of manganese dioxide. The $pH_{PZC}$ (point of zero charge) is found to be 6.28. Further, the IMNS is assessed in the removal of As(III) and As(V) pollutants from aqueous solutions under the batch and column operations. Batch reactor experiments are conducted for various physicochemical parametric studies, viz. the effect of sorptive pH (pH 2.0-10.0), concentration (1.0-25.0 mg/L), and background electrolyte concentrations (0.0001-0.1 mol/L $NaNO_3$). Further, column experiments are conducted to obtain the efficiency of IMNS under dynamic conditions. The breakthrough data obtained by the column experiments are employed in non-linear fitting to the Thomas equation, so as to estimate the loading capacity of the column for As(III) and As(V).

The Effect of Heat Curing Methods on the Protection against Frost Damage at Early Age of the Concrete Under Extremely Cold Climate

  • Jung, Eun-Bong;Shin, Hyun-Sup;Han, Min-Cheol
    • Journal of the Korea Institute of Building Construction
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    • v.13 no.6
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    • pp.513-521
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    • 2013
  • This study aimed to examine whether heat curing methods of concrete subjected to $-10^{\circ}C$ could be effective by varying the combination of heating cable and surface heat insulations. Three different concrete specimens incorporating 30% fly ash with 50% W/B were fabricated to simulate wall, column and slab members with dimensions of $1600{\times}800{\times}200$ mm for slab, $800{\times}600{\times}200$ mm for wall and $800{\times}800{\times}800$ mm for column. For heat curing combinations, Type-1 specimens applied PE film for slab, plywood for wall and column curing. Type-2 specimens applied double layer bubble sheet (2LB) and heating coil for slab, and 50 mm styrofoam for wall and column curing. Type-3 specimen applied 2LB for slab, electrical heating mat for wall and column inside heating enclosure. The test results revealed that the temperature of Type 1 specimen dropped below $0^{\circ}C$ beginning at 48 hours after placement due to its poor heat insulating capability. Type 2 and 3 specimens maintained a temperature of around $5{\sim}10^{\circ}C$ after placement due to favorable heat insulating and thermal resistance.

Biodegradation of Diesel by Rhodococcus fascians in Sand Column (Rhodococcus fascians를 이용한 모래 컬럼내 디젤유 분해)

  • Moon, Jun-Hyung;Koo, Ja-Ryong;Yun, Hyun-Shik
    • KSBB Journal
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    • v.26 no.1
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    • pp.1-6
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    • 2011
  • Contamination of soils, groundwater, air and marine environment with hazardous and toxic chemicals is major side effect by the industrialization. Bioremediation, the application of microorganism or microbial processes to degrade environmental contaminant, is one of the new environmental technologies. Because of low water solubility and volatility of diesel, bioremediation is more efficient than physical and chemical methods. The purpose of this study is biodegradation of diesel in sand by using Rhodococcus fascians, a microorganism isolated from petroleum contaminated soil. This study was performed in the column containing sand obtained from sea sides. Changes in biodegradability of diesel with various flow rates, inoculum sizes, diesel concentrations, and pH were investigated in sand column. The optimal condition for biodegradation of diesel by R. fascians in sand column system was initial pH 8 and air flow rate of 30 mL/min. Higher diesel degradation was achieved at larger inoculum size and the diesel degradation by R. fascians was not inhibited by diesel concentration up to 5%.