Azarbaijan Shahid Madani University

About: Azarbaijan Shahid Madani University is a education organization based out in Tabriz, Iran. It is known for research contribution in the topics: Graphene & Nanocomposite. The organization has 1477 authors who have published 3186 publications receiving 30278 citations. The organization is also known as: Azarbaijan University.

An Investigation on Rotating Bending Fatigue Behavior of Nanostructured Low-Temperature Bainitic Steel

Abstract: The aim of this work is to investigate the fatigue behavior of a new class of nanostructured, low-temperature bainitic steels, where rotating bending fatigue tests were conducted on samples isothermally transformed at 300, 250, and 200 °C, after which, fracture surfaces were examined using scanning electron microscopy. Results showed that, fatigue limits of about 820, 945, and 1,005 MPa were achieved for the samples transformed at each transformation temperature, respectively. Moreover, according to the SEM micrographs, secondary crack initiation was observed in the high carbon retained austenite blocks for samples transformed at 300 °C and at the interface of blocky austenite-bainitic ferrite for samples transformed at 250 and 200 °C.

A novel all-steel buckling restrained brace for seismic drift mitigation of steel frames

Abstract: Buckling restrained braces (BRBs) as metallic dampers can supply stable and balanced hysteretic response. While BRBs exhibit outstanding energy dissipation capacity, their low post-yield stiffness contributes to large residual drift concentration in simply supported buckling restrained braced frames. The present study introduces a novel all-steel tube-in-tube BRB composed of a short-length hybrid core serially connected to a non-yielding robust member. The hybrid core includes short-length yielding members made up of circular hollow sections surrounded by an all-steel encasing system. High strain hardening capacity of short-length hybrid core enhances the post-yield stiffness, thus reducing the residual drift in simply supported buckling restrained braced frame. In this paper, first the components of proposed brace are represented in detail. Subsequently, the design procedure and stability analysis results are provided. The feasibility of conceptual hybrid BRB is evaluated by finite element analysis method. Afterwards, the global response of prototype buckling restrained braced frames comprising conventional and proposed braces are appraised via pushover and nonlinear time history analyses. The analyses results designated the significant efficiency of proposed braces to help mitigate inter-story and particularly residual drifts in buckling restrained braced frames.

Enhanced properties of photovoltaic devices tailored with novel supramolecular structures based on reduced graphene oxide nanosheets grafted/functionalized with thiophenic materials

Abstract: For verifying the influence of donor–acceptor supramolecules on photovoltaic properties, different hybrids were designed and used in organic solar cells. In this respect, reduced graphene oxide (rGO) was functionalization with 2-thiophene acetic acid (rGO-f-TAA) and grafted with poly(3-dodecylthiophene) (rGO-g-PDDT) and poly(3-thiophene ethanol) (rGO-g-PTEt) to manipulate orientation of poly(3-hexylthiophene) (P3HT) assemblies. Face-on, edge-on, and flat-on orientations were detected for assembled P3HTs on rGO and its functionalized and grafted derivatives, respectively. Alteration of P3HT orientation from face-on to flat-on enhanced current density (Jsc), fill factor (FF), and power conversion efficiency (PCE) and thus Jsc = 7.11 mA cm−2, FF = 47%, and PCE = 2.14% were acquired. By adding phenyl-C71-butyric acid methyl ester (PC71BM) to active layers composed of pre-designed P3HT/rGO, P3HT/rGO-f-TAA, P3HT/rGO-g-PDDT, and P3HT/rGO-g-PTEt hybrids, photovoltaic characteristics further improved, demonstrating that supramolecules appropriately mediated in P3HT:PC71BM solar cells. Phase separation was more intensified in best-performing photovoltaic systems. Larger P3HT crystals assembled onto grafted rGOs (95–143 nm) may have acted as convenient templates for the larger and more intensified phase separation in P3HT:PCBM films. The best performances were reached for P3HT:P3HT/rGO-g-PDDT:PCBM (Jsc = 9.45 mA cm−2, FF = 54%, and PCE = 3.16%) and P3HT:P3HT/rGO-g-PTEt:PCBM (Jsc = 9.32 mA cm−2, FF = 53%, and PCE = 3.11%) photovoltaic systems. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017