Application of Codes Performance‐Based Design Procedures for a Tall Building Using Recorded and Spectrally Modified Ground Motions

There is a growing tendency toward the performance‐based design of tall buildings, where any assessment using response history analysis requires a set of ground motion (GM) records. This paper considering a tall building as a case study investigates how judgment on the seismic safety of the structure is affected by the use of recorded or spectrally matched GMs. Three model structures are developed: (a) using conventional design procedure of Chapter 12 of ASCE 7‐16; (b) adopting linear analysis requirements of Chapter 16 of ASCE 7‐16; (c) designing for service‐level design earthquake of Los Angles Tall Building Structural Design Council (LATBSDC) procedure. It is shown that all of the structures give acceptable performance when subjected to simulated GMs, although this is not the case for amplitude‐scaled GMs based on ASCE 7‐16 and LATBSDC. Finally, to have an objective assessment of performance, independent of GM types, incremental dynamic analysis is employed to derive fragility and mean annual rate of exceeding (MAR). Results show that for anticipated drifts at Maximum Considered Earthquake (MCE) level, the structures provide acceptable MAR at the fundamental period. However, for the higher modes including the second and third periods, MAR values become acceptable only at drifts as large as 0.085.     

CH4 reforming with CO2 for syngas production over nickel catalysts supported on mesoporous nanostructured γ-Al2O3

Nanostructured γ-Al₂O₃ with high surface area and mesoporous structure was synthesized by sol-gel method and employed as catalyst support for nickel catalysts in methane reforming with carbon dioxide. The prepared samples were characterized by XRD, BET, TPR, TPH, SEM and TPO techniques. The BET analysis showed a high surface area of 204m²g^?1 and a narrow pore-size distribution centered at a diameter of 5.5 nm for catalyst support. The results revealed that an increase in nickel loading from 5 to 15 wt% decreased the surface area of catalyst from 182 to 160 m²g^?1. In addition, the catalytic results showed an increase in methane conversion with increase in nickel content. TPO analysis revealed that the coke deposition increased with increasing in nickel loading, and the catalyst with 15 wt% of nickel showed the highest degree of carbon formation. SEM and TPH analyses confirmed the formation of whisker type carbon over the spent catalysts. Increasing CO₂/CH₄ ratio increased the methane conversion. The BET analysis of spent catalysts indicated that the mesoporous structure of catalysts still remained after reaction.     

Evaluation of the Electroslag Remelting Process in Medical Grade of 316LC Stainless Steel

This study is focused on the effects of electroslag remelting by prefused slag(CaO,Al2O3,and CaF2)on macrostructure and reduction of inclusions in the medical grade of 316LC(316LVM)stainless steel.Analysis of the obtained results indicated that for production of a uniform ingot structure during electroslag remelting, shape and depth of the molten pool should be carefully controlled.High melting rates led to deeper pool depth and interior radial solidification characteristics,while decrease in the melting ra...     

Preparation and electromagnetic properties of Ni1−xCuxFe2O4 nanoparticle ferrites by sol-gel auto-combustion method

The Cu-Ni ferrite (Ni_1−xCu_xFe₂O₄) nanopowders were prepared using the sol-gel auto-combustion method. The synthesized nanopowder can be densified at a temperature lower than 950 °C. The Cu content has a significant influence on the electromagnetic properties, such as initial permeability, resistivity and dielectric loss tangent. The possible reasons that are responsible for the composition dependence of the main electromagnetic properties were discussed.     

Degradation of toluidine red,an oil soluble azo dye by Halomonas strain IP8 at alkaline condition

A salt tolerant bacteria, Halomonas strain IP8, was used for the degradation of an oil soluble azo dye, Toluidine Red (C.I. no. 12120). The effect of different culture conditions such as initial dye concentration, pH, NaCl percent (w/v) and temperature were studied at static condition using the one-factor-at-a-time method (OFAT) method as optimization technique. According to the results, the optimized conditions were 25?mg/l dye concentration, pH 9.5, 5% (w/v) NaCl, and temperature 35?°C. The decolorization mechanism was analyzed through UV–vis spectrophotometric method, high-performance liquid chromatography (HPLC), and gas chromatography-mass spectrometer (GC-MS) analyses. UV–vis scan of supernatants before and after treatment suggested that decolorization was accrued under degradation mechanism rather than inactive surface adsorption. HPLC analysis confirmed this conclusion. The identified metabolite from GC-MS results was 1-diazo 2-naphtol at m/z 170?±?1. A pathway was proposed for dye degradation based on the identified fragment by GC-MS analysis.     

Effects of different filling media on the oxidation and lipid quality of canned silver carp (Hypophthalmichthys molitrix)

The influence of four different filling media (sunflower oil, soybean oil, olive oil and brine) on the oxidation and lipid quality of canned silver carp was evaluated. Hydrolytic rancidity showed that free fatty acid contents in brine and soybean oil canned muscle were higher than olive oil or sunflower oil canned samples. Conjugated diene (CD) levels in soybean oil canned samples increased but the highest CD values were found in canned silver carp using brine as filling medium. Except for olive oil canned muscle, significant increase in thiobarbituric acid (TBA) values was obtained. The highest TBA value was observed in soybean oil canned sample. Canning led to exchange of fatty acids between the fat in the silver carp muscle and the filling media used. Results indicate that the fat composition of canned silver carp tends to be similar to that of the fat used as filling media.     

Investigation on using high-pressure fluid jet in grinding process for less wheel loaded areas

Wheel loading entails chip accumulation in porosities between grains or welding to the top of cutting grains. It is considered one of the most prevalent problems in grinding nickel-based super alloys. Utilizing separate jet cleaning systems can significantly reduce wheel loading. In this study, a separate high-pressure coolant was supplied through a nozzle towards the wheel surface to flush out the chips. The effects of various wheel cleaning parameters on the loaded area to wheel surface ratio in relation to grinding performance were examined. It was observed that the lowest wheel loading was achieved at a nozzle standoff distance of 70 mm from the wheel’s surface. Nozzle stream direction had no significant effect. Increasing flow rate and jet speed led to a significant decrease in wheel loading and corresponding specific energy until a threshold value was reached. Furthermore, the loaded area to wheel surface ratio was reduced by 100 % and the corresponding specific energy by up to 30 % when the wheel cleaning system was employed.     

An auto-scaling mechanism for cloud-based multimedia storage systems: a fuzzy-based elastic controller

Multimedia Tools and Applications - Cloud computing is a new technology that is increasing in popularity day-by-day. One of the reasons for its popularity can be its elasticity feature. In other...     

Three-dimensional graphene promoted by palladium nanoparticles,an efficient electrocatalyst for energy production and storage

Three-dimensional (3D) graphene was easily obtained by a simple hydrothermal method from two-dimensional (2D) graphene to create the interspace sites and active surface area. So, the fabrication of the 3D-graphene nanocomposite is promising for advanced energy production and storage application. The structure of the 3D-graphene nanocomposite was characterized by various techniques. Then, 3D-graphene was decorated with Pd nanoparticles. Morphological characterization shows the porous structure of 3D-Pd/rGO, so it has a high electroactive surface area. The function of the electrocatalyst toward the supercapacitor, hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) were investigated. The obtained results as a supercapacitor displayed that the supercapacitor on 3D-Pd/rGO has a high specific capacitance of 582.0 F g^?1, the high energy density of 180 (W h Kg^?1), high power density of 3750 (W Kg^?1), long potential window of 1.00 V and long life. The electrocatalyst shows the small onset potential of ?0.08 V (vs. RHE), Tafel slope of 29 mV dec^?1 and high durability. Also, in the electroanalytical application of the nanocompound as an electrocatalyst for ORR shows an excellent onset potential of 0.90 V (vs. RHE), slow drop in the current density (34% in the presence of MeOH) and the reduction process via a four electrons pathway.     

Characterization of CeO2 Promoter of a Nanocrystalline Ni/MgO Catalyst in Dry Reforming of Methane

Ceria‐promoted nickel catalysts supported on nanocrystalline MgO were prepared and employed in methane reforming with CO₂. Their characterization was accomplished by X‐ray diffraction, BET, temperature‐programmed oxidation, and temperature‐programmed reduction (TPR) techniques. Cerium oxide (CeO₂) proved to have a positive effect on catalytic activity, stability, and carbon suppression in methane reforming with CO₂. A higher CeO₂ content increased the catalyst activity and decreased the amount of deposited carbon over the spent catalysts. The suppression of carbon was related to the high oxygen storage capacity of CeO₂. In addition, TPR analysis revealed that the CeO₂ promoter reduced the chemical interaction between nickel and support, resulting in an increase in reducibility and higher dispersion of nickel.