T. Turgay

Evaluation of the Predictive Models for Stiffness, Strength, and Deformation Capacity of RC Frames with Masonry Infill Walls

AbstractBuildings with masonry infill walls (MIWs) in reinforced concrete (RC) frames are commonly used all around the world. It is well known that infill walls may affect the strength, stiffness, and displacement ductility of the structural system. Different approaches have been adopted in different codes and guidelines to consider the stiffness and strength contribution of MIWs on RC frame behavior. This study compares the ability of the existing guidelines to estimate stiffness, strength, and deformability of RC frames with MIWs by using a compiled experimental database composed of 51 experiments from 24 different studies. Alternative expressions are proposed in this study to provide improved estimates of stiffness and deformability of infilled RC frames.

Decrement in metastability with Zr nanoparticles inserted in Bi-2223 superconducting system and working principle of hybridization mechanism

Abstract This exhaustive study experimentally deals with the role of Zr foreign impurities on the electrical, superconducting and flux pinning properties of the bulk Bi-2223 superconducting compounds by the typical experimental characterization methods such as dc resistivity (ρ–T), transport critical current density (Jc) and powder X-ray diffraction (XRD) surveys. All the experimental findings show that the curial characteristics, being in charge of the varied attractive and feasible applications, retrograde significantly with the enhancement of the Zr nanoparticles in the Bi-2223 superconducting system due to the presence of two trap levels for mobile holes. This leads to the degradation of the metastability of the superconducting materials. In more detail, based on the dc resistivity and transport critical current density measurements, the Zr additives give rise to the localization problem as a consequence of the change in the dynamics of electron–electron interaction. Thus, the room state conductivity,

Compressive behavior of large-scale square reinforced concrete columns confined with carbon fiber reinforced polymer jackets

T_{c}^{onset}

Stress―strain model for concrete confined with CFRP jackets

Tconset,

Solubility limit of tetravalent Zr nanoparticles in Bi-2223 crystal lattice and evaluation of fundamental characteristic properties of new system

T_{c}^{offset}

A detailed research for determination of Bi/Ga partial substitution effect in Bi-2212 superconducting matrix on crucial characteristic features

Tcoffset and Jc values retrograde significantly. Similarly, the Zr foreign impurities embedded in the Bi-2223 crystal lattice make the artificial random defects, dislocations and grain boundary weak-interactions in the consecutively stacked layers enhance immediately, and the superconducting Cu–O2 layers distort especially. Moreover, the XRD investigations including the evidences about the decrement/increment in the c-axis/a-axis length verify the regression of the superconducting properties with the Zr dopant. The main differentiation of the lattice constant parameters stems from aliovalent substitutions (replacement of the divalent Cu by the tetravalent Zr impurties) along with the crystal structure. In other words, the reduction of the electronegativity leads to decrease the mobile hole concentration in the Cu–O2 consecutively stacked layers. Furthermore, all the decrement parameters are theoretically favored by hybridization mechanism.