• Journal of the Korean Society of Tobacco Science
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• v.5 no.2
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• pp.63-69
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• 1983

The tensile strength (Pm) . elongation percentage ($\varepsilon$) , elastic modulus (I) , and specific volume (Sv) were calculated from the data of tensile characteristics of By 104 .and Burley 21 tobacco leaves, which were measured over a relative humidity from 60 to 80% at $20\pm2^{\circ}C$.The important results obtained were as follows.(1) Tensile strength(Pm) The "Pm"of By 104 was greater than that of Burley at. The "Pm"in both varieties were increased toward the upper stalk position and according to the decrease of relative humidity. The "Pm" of parallel piece to tile vein in a leaf were greater than that of right angle piece to the vein. (2) Elongation percentage ($\varepsilon$). The "s" of By 104 was higher than that of Burley 21. The "s" in both varieties were increased toward the upper stalk position and according to the increase of relative humidity. The "s" of parallel Piece to the vein in a Burley leaf was greater than that of right angle piece to the vein. (3) Elastic modulus (E) The "E" of Burley 21 leaf was higher than that of By 104. The "E" in both varieties were increased toward the lower stalk position and according to decrease of relative humidity. The "E"of parallel piece to the vein in both varieties leaves were greater than that of right angle piece to tile vein. (4) Specific volume (Sv) The "Sv" of Burley 21 leaf was increased than that of By 104. The "Sv" in both varieties were increased toward the lower stalk position and according to the decrease of relative humidity.ot;Sv" in both varieties were increased toward the lower stalk position and according to the decrease of relative humidity.dity.

• Macromolecular Research
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• v.13 no.2
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• pp.81-87
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• 2005

Blends of silicone rubber (VMQ) and liquid crystalline polymer (LCP) were prepared by the melt mixing technique. Mechanical, XRD, thermal and dynamic mechanical investigations are reported for the pure silicone rubber and blends. The mechanical properties, viz. the tensile strength, tear strength and elongation at break, of the silicone rubber decreased with the addition of LCP. The SEM study on the tensile fractured surface of the blends revealed that they had a two phase structure, and that the failure was mainly due to fiber pull out, which suggests that the VMQ and LCP are incompatible in all of the proportions examined in this study. However, the FTIR study shows that there was a partial interaction between the VMQ and LCP, but which may not be sufficient to grip the fibrils under the applied load. In the XRD analysis, it was observed that the crystalline structure of the silicone rubber deteriorated in the presence of LCP. The DMA study suggested that the storage modulus of the silicone rubber was improved with the addition of LCP, due to the high modulus of the LCP phase. The thermal stability of the silicone rubber was greatly reduced by the addition of LCP, due to the latter having a thermal stability lower than that of silicone rubber.

• Steel and Composite Structures
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• v.30 no.2
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• pp.171-183
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• 2019

As China's infrastructure continues to grow, concrete filled steel tubular (CFST) structures are attracting increasing interest for use in engineering applications in earthquake prone regions owing to their high section modulus, high strength, and good seismic performance. However, in a corrosive environment, the seismic resistance of the CFST columns may be affected to a certain extent. This study attempts to investigate the mechanical behaviours of square CFST members under both a cyclic load and an acid rain attack. First, the tensile mechanical properties of steel plates with various corrosion rates were tested. Second, a total of 12 columns with different corrosion rates were subjected to a reversed cyclic load and tested. Third, comparisons between the test results and the predicted ultimate strength by using four existing codes were carried out. It was found that the corrosion leads to an evident decrease in yield strength, elastic modulus, and tensile strain capacity of steel plates, and also to a noticeable deterioration in the ultimate strength, ductility, and energy dissipation of the CFST members. A larger axial force ratio leads to a more significant resulting deterioration of the seismic behaviour of the columns. In addition, the losses of both thickness and yield strength of an outer steel tube caused by corrosion should be taken into account when predicting the ultimate strength of corroded CFST columns.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.11-12
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• 2014

In this study, fundamental properties of concrete mixed with fiber has been analysed. Compressive strength, tensile strength and plastic shrinkage has been tested to conduct the optimum addition ratio of fiber. Effect to control press concrete's cracking has been tested. The following results could be made as the conclusion. For the flowability, slump decreased about 41-79% when all types of fiber used in the concrete. When the addition ratio of fiber is 1.2%, the slump of concrete decreased about 45%. For the strength properties. all the specimens with different addition ratio of fiber shown higher compressive strength comparing with Plain. Comparing with Plain, cracking decreased when the fiber added. Especially, when NY fiber used in the concrete, the plastic shrinkage did not occurred. In addition, Latex modified concrete(LMC) has improved superior physical and chemical properties. The properties of latex, combined with the low water-cement ratio, produce a concrete that has improved flexural, tensile, and bond strength, lower modulus of elasticity, increased freeze-thaw resistance, and reduced permeability compared to conventional concrete of similar mix design.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.139-142
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• 1999

The purpose of this experimental research is to investigate the mechanical properties of ordinary strength and high strength concrete containing waste glass powder. For this purpose, after production of concrete containing waste glass powder for different unit weight of binder and placement ratio of waste glass powder, optimum mixing proportions of them was determined, and then mechanical properties such as static modulus of elasticity as well as compressive, tensile and flexural strength were tested and analyzed for concrete produced according to optimum mixing proportions. As a result, the concrete containing waste glass powder has as excellent workability and strength, it's strengths are analogus to those of silica fume, it's workability is somewhat better than that of silica fume.

• International Journal of Concrete Structures and Materials
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• v.5 no.1
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• pp.3-10
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• 2011

Theoretical models for prediction of the mechanical properties of cement mortar are developed based on the morphology and interactions of cement hydration products, capillary pores and microcracks. The models account for intermolecular interactions involving the nano-scale calcium silicate hydrate (C-S-H) constituents of hydration products, and consider the effects of capillary pores as well as the microcracks within the hydrated cement paste and at the interfacial transition zone (ITZ). Cement mortar was modeled as a three-phase material composed of hydrated cement paste, fine aggregates and ITZ. The Hashin's bound model was used to predict the elastic modulus of mortar as a three-phase composite. Theoretical evaluation of fracture toughness indicated that the frictional pullout of fine aggregates makes major contribution to the fracture energy of cement mortar. Linear fracture mechanics principles were used to model the tensile strength of mortar. The predictions of theoretical models compared reasonably with empirical values.

• Transactions of Materials Processing
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• v.15 no.5 s.86
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• pp.360-365
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• 2006

Carbon nanotubes (CNTs) have been the subject of intensive studies for applications in the fields of nano technologies in recent years due to their superior mechanical, electric, optical and electronic properties. Because of their exceptionally small diameters (${\appros}\;several\;nm$) as well as their high Young's modulus (${\appros}1\;TPa$), tensile strength (${\appros}\;200\;GPa$) and high elongation (10-30%) in addition to a high chemical stability, CNTs are attractive reinforcement materials for light weight and high strength metal matrix composites. Although extensive researches have been performed on the electrical, mechanical and functional properties of CNTs, there are not many successful results on the mechanical properties of CNT dispersed nanocomposites. In this paper, we applied equal channel angular pressing for consolidation of CNT/Cu powder mixtures. We also investigated the hardness and microstructures of CNT/Cu nanocomposites used experimental for metal matrix composites.

• Applied Chemistry for Engineering
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• v.29 no.3
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• pp.318-324
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• 2018

In this study, PAN (polyacrylonitrile) based activated carbon fibers were prepared by water vapor activation method which is a physical activation method. Activation was performed with temperature and time as parameters. When the activation temperature reached 700, 750 and $800^{\circ}C$, the activation was carried out under the condition of a water vapor flow rate of 200 ml/min. In order to analyze the pore structure of activated carbon fibers, the specific surface area ($S_{BET}$) was measured by the adsorption/desorption isotherm of nitrogen gas and AFM analysis was performed for the surface analysis. Tensile tests were also conducted to investigate the effect of the pore structure on mechanical properties of fibers. As a result, the $S_{BET}$ of fibers after the activation showed a value of $448{\sim}902m^2/g$, the tensile strength decreased 58.16~84.92% and the tensile modulus decreased to 69.81~83.89%.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.2001-2005
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• 2005

The tensile test is generally used to measure mechanical properties with conventional fracture test. This test is extremely certain method to measure Young's modulus, yield strength, tensile strength and so on. ASTM, by international standard, prescribes two classes of tensile tests in tubular products. One is method that specimens aren't done by any process with Tube-shape. The other is that specimens are made on process for C-shape. In this paper, we would like to present the new-shape specimens for the tensile test. The presented specimen's shape is that put two pieces of C-shape specimens together. Besides a load point and a support point are fixed like Tube-shape specimens. This shape of specimen has a difference that existing specimen is made on one-step process out this specimen is made on two-step process. This shape is considered that stress concentration phenomenon occurs at the reduced section if a specimen is made on one step process.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.1
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• pp.100-106
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• 2006

Today, restricted energy sources, environmental considerations and the high cost of transporting fuel have limited the number and location of available power plant sites. The pressures resulting from these conditions have tended to require the construction of long, high-capacity, high-voltage power lines. it's used to adapt to STACIR/AW(Super Thermal-resistant Aluminum alloy Conductors, aluminum-clad Invar-Reinforced) conductor for coping with these situations. STACIR/AW conductor was formed by the combination of INVAR/AW as the core for low sag and super thermal-resistant aluminum alloy conductor for current capacity increase. increase of temperature by current capacity and long span lines make the susceptible to the deterioration of thermo-mechanical properties(conductivity, tensile strength, E-modulus and twist property et al). In the present work, changes of thermo-mechanical properties with aging have been studied in STACIR/AW $410 mm^2$ conductor with forms of single wire and strand wire.