Sharif Digital Repository

The results of an experimental investigation on some engineered infilled frames with high ductility and adjustable strength are presented in this paper. To achieve an engineered infilled frame, an element is added to the infill, called Frictional Sliding Fuses (FSFs). The fuse acts before infill corner crushing and controls the infill so that it is not overloaded. Consequently, it increases the deformation capacity and decreases the strength deterioration. An FSF has a frictional nature, based on which the infill has more appropriate hysteresis cycles, leading to more structural energy damping during earthquakes. The results show that the engineered infilled frames have adjustable strength,... 

An experimental investigation is conducted here to study the effects of applying frictional sliding fuses (FSF) in concrete infilled steel frames. Firstly, the influences of some parameters on the behavior of the sliding fuse are studied: Methods of adjusting the FSF for a certain sliding strength are explained and influences of time duration, welding and corrosion are investigated as well. Based on the results, time duration does not significantly affect the FSF, however influences of welding and corrosion of the constitutive plates are substantial. Then, the results of testing two 1/3 scale single-storey single-bay concrete infilled steel frames having FSF are presented. The specimens were... 

The morphological manipulation, structural characterization, and optical properties of different CdSe nanocrystals were reported. Several different CdSe nanostructures, including nanowires, tetrapod crystals, and nanoparticles were grown by varying the volume ratio of triethylenetetraamine (TETA) and water (WA) in their mixed solution. By manipulating the growth driving force (i.e., the degree of supersaturation) and kinetics of the process (i.e., growth rate), the morphology and crystal structure of CdSe nanocrystals can be tailored. Growth driving force changed their morphology from nanowires to tetrapod structures and from the latter structure to nanoparticles. Moreover, kinetics of the... 

In this paper, the nonlinear transversal vibration of an axially moving viscoelastic string on a viscoelastic guide subjected to a mono-frequency excitation is considered. The model of the viscoelastic guide is a parallel combination of springs and viscous dampers. The governing equation of motion is developed using Hamilton's principle. Applying the method of multiple scales to the governing partial differential equation, the solvability condition and approximate solutions are derived. Three cases, namely primary, subharmonic and superharmonic resonances are studied and appropriate analytical solutions are obtained. The effect of mean value velocity, force amplitude, guide stiffness and... 

Purpose: An abdominal aortic aneurysm (AAA) is known as a cardiovascular disease involving localized deformation (swelling or enlargement) of aorta occurring between the renal and iliac arteries. AAA would jeopardize patients’ lives due to its rupturing risk, so prompt recognition and diagnosis of this disorder is vital. Although computed tomography angiography (CTA) is the preferred imaging modality used by radiologist for diagnosing AAA, computed tomography (CT) images can be used too. In the recent decade, there has been several methods suggested by experts in order to find a precise automated way to diagnose AAA without human intervention base on CT and CTA images. Despite great... 

The efficiency of low salinity waterflooding, particularly during tertiary mode injection, is highly controlled by in situ mixing between the stagnant regions holding high salinity water (HSW) and the flowing regions containing low salinity water (LSW) because it impacts directly the electrokinetics of wettability alteration and the time scale of the low salinity effect. This study aims to address the effects of oil polarity and charged rock surfaces on the time scale of mixing and transport under two-phase flow conditions. A systematic series of micromodel experiments were performed. The micromodels were first saturated with high salinity formation brine and oil (both model and crude oil);... 

The asymmetric unit of the title compound, C14H 11BrN2O2, contains two independent mol-ecules connected into a dimer by inter-molecular N - H⋯O hydrogen bonds involving the amine and carbonyl groups. The dimers are further connected by O - H⋯O hydrogen bonds, forming chains running parallel to the a axis, which are stabilized through π-π stacking inter-actions, with a centroid-centroid distance of 3.679 (8) Å. The dihedral angle between the two aromatic rings is 89.2 (4)°  

One of the most critical issues in manufacturing systems is the operator management. In this paper, the operator assignment problem is studied within a cellular manufacturing system. The most important novelty of this research is the consideration of operator learning and forgetting effects simultaneously. The skill level of an operator can be increased/decreased based on the time spent on a machine. Moreover, the issues related to operators like hiring, firing, and salaries are considered in the proposed model. The parameters are considered to be uncertain in this model, and a robust optimization approach is developed to handle it. Using this approach, the model solution remains feasible... 

Perovskite solar cells have been constructed under the standard procedure by employing soluble tetratriphenylamine-substituted Zn phthalocyanine as hole transporting material. Solution processed device construction was carried out under ambient conditions of 50–60% ambient humidity. Triphenylamine substitution played the double role of imparting solubility to the core metal phthalocyanine as well as to introduce electron-rich ligands, which could enhance the role of Zn phthalocyanine as hole transporter. Indeed, the obtained material was functional. The present data highlight tetratriphenylamine-substituted Zn phthalocyanine as hole transporting material but also highlight the importance of... 

In this paper, an innovative seismic lateral force resisting system for tall buildings is introduced. In this system, a novel supplemental part, ribbed bracing system (RBSyst), is attached to Braced Tube System, creating a modified BTS. RBSyst is a supplemental part which is attached to the conventional bracing members to eliminate buckling problem. The behavior of RBSyst under tensile force is similar to that of the conventional braces. However, in compression, it prevents the braces from buckling by length reduction. In order to evaluate the efficiency of this new BTS system by performance-based assessment, two typical 40-story tall buildings with different story modules equipped with this... 

This study presents the experimental investigation of half-scale, one-story, one-bay pinned frames equipped with a ribbed bracing system (RBS). The RBS is a newly developed passive control system designed to eliminate buckling and enhance the seismic behavior of structures. Here, mechanical models of this bracing system were designed and constructed. Pinned frames equipped with the RBS were cyclically tested. The hysteretic behavior and energy absorbing capacities of the frames were evaluated. Based on the results, the full plastic capacity of the brace was achieved and no buckling occurred. The RBS frame illustrated proper hysteretic behavior and energy dissipation capacity up to 4% story... 

Carbon based perovskite solar cells have been constructed by screen-printing three subsequent mesoporous layers of Titania, Zirconia and Carbon without a hole transporting layer and by infiltration of perovskite liquid precursor through the layers. Cell efficiency was optimized by varying the thickness of the three layers and the composition of the inks employed for screen printing. Electrochemical impedance spectroscopy was employed as a guide in the search for layer thickness optimization. All cell construction and testing was carried out under ambient conditions of 20–30% humidity. The cells were not encapsulated. The best cell gave an efficiency of 10.7%. All cells demonstrated a... 

This study presents the experimental investigation of half-scale, one-story, one-bay pinned frames equipped with a ribbed bracing system (RBS). The RBS is a newly developed passive control system designed to eliminate buckling and enhance the seismic behavior of structures. Here, mechanical models of this bracing system were designed and constructed. Pinned frames equipped with the RBS were cyclically tested. The hysteretic behavior and energy absorbing capacities of the frames were evaluated. Based on the results, the full plastic capacity of the brace was achieved and no buckling occurred. The RBS frame illustrated proper hysteretic behavior and energy dissipation capacity up to 4% story... 

In this article, a novel passive control system, ribbed bracing system (RBS), has been proposed to deal with the buckling problem. RBS is a bracing system with a simple mechanism that can be installed in braces as a supplemental part. The behavior of RBS is similar to that of conventional braces under tensile loading. However, under compressive force, it endures an insignificant force and prevents the braces from buckling through length reduction. In addition, seismic damage is concentrated in the bracing system of the structures equipped with RBS, decreasing the dissipated hysteretic energy in other structural members. There are two different mechanisms for RBS: 1) completely-closed RBS... 

In this paper, an innovative seismic lateral force resisting system for tall buildings is introduced. In this system, a novel supplemental part, ribbed bracing system (RBSyst), is attached to Braced Tube System, creating a modified BTS. RBSyst is a supplemental part which is attached to the conventional bracing members to eliminate buckling problem. The behavior of RBSyst under tensile force is similar to that of the conventional braces. However, in compression, it prevents the braces from buckling by length reduction. In order to evaluate the efficiency of this new BTS system by performance- based assessment, two typical 40-story tall buildings with different story modules equipped with... 

Aluminum reinforced with a large amount (up to about 55 vol.%) of Al 3Ti particles can be fabricated from Al-20Ti elemental nanometer-sized powder mixture via in-situ two step hot press sintering (TSS). For production of intermetallic reinforced in-situ composite, TSS can provide elevated temperature to facilitate the formation of intermetallic phase in situ and hot consolidation to form a fully dense solid. The first step sintering was employed at a higher temperature to obtain an initial high density, and the second step was held at a lower temperature by isothermal sintering for more time than the first one to increase bulk density without significant grain growth. The optimum TSS regime... 

In this study, a general 3D distributed modeling of Trolling-Mode AFM (TR-AFM) as a nanorobot is presented to analyze the 2D manipulation process of a spherical cell. To this aim, the analysis is categorized into 3 sections. In the first section, 6 deformations of TR-AFM are taken into account, and the standard model of the system is obtained. Moreover, the system is simulated in ANSYS Workbench. The results of modal and transient analyses of the system from both analytical and software methods reveal high agreement, which confirms the accuracy of the presented analytical model. In the second section, by utilizing the 3D derived model, displacement of a spherical yeast single cell (W303)... 

The anatase phase of titania was stabilised with physically modifying particulate sol-gel process. Two major parameters, peptisation temperature and drying temperature, were identified which were responsible for retarding the anatase to rutile phase transformation, crystal growth and packing of primary particles. The critical nucleus size of transformation was controlled by natural (at 25 °C) and artificial (at 50 and 70 °C) peptisation techniques. Moreover, sintering of primary particles was controlled by cool (at 0 and 5 °C) and normal (at 25 °C) drying techniques. Fourier transform infrared spectroscopy (FT-IR) analysis confirmed that a full conversion of titanium isopropoxide is obtained... 

In this paper we present flexible strain sensors made of graphene flakes fabricated, characterized, and analyzed for the electrical actuation and readout of their mechanical vibratory response in strain-sensing applications. For a typical suspended graphene membrane fabricated with an approximate length of 10 μm, a mechanical resonance frequency around 136 MHz with a quality factor (Q) of ∼60 in air under ambient conditions was observed. The applied strain can shift the resonance frequency substantially, which is found to be related to the alteration of physical dimension and the built-in strain in the graphene flake. Strain sensing was performed using both planar and nonplanar surfaces... 

Irrigation is the largest human intervention in the water cycle that can modulate climate extremes, yet irrigation water use (IWU) remains largely unknown in most regions. Microwave remote sensing offers a practical way to quantify IWU by monitoring changes in soil moisture caused by irrigation. However, high-resolution satellite soil moisture data is typically infrequent (e.g., 6–12 days) and thus may miss irrigation events. This study evaluates the ability to quantify IWU by assimilating high-resolution (1 km) SMAP-Sentinel 1 remotely sensed soil moisture with a physically based land surface model (LSM) using a particle batch smoother (PBS). A suite of synthetic experiments is devised to...