Sharif Digital Repository

A high performance asymmetric supercapacitor (ASC)has been fabricated by using nickel oxide-cobalt oxide nanosheets (NiO–CoO NSs), which were directly grown on carbon nanotubes (CNTs)and hydrothermal carbon spheres (HTCs)as positive and negative electrodes, respectively. Both electrode materials are binder-free prepared by using a catalytic chemical vapour deposition (CVD)approach followed by a facile hydrothermal method for cathode and a one-step environmental-friendly route called hydrothermal carbonization for anode. Using NiO–CoO NSs@CNTs and HTCs, which were directly grown on Ni foam, not only leads to a very small equivalent series resistance, but also provides an impressive capacitive... 

The development of high performance supercapacitors with high energy densities without sacrificing power densities has always been at the leading edge of the emerging field of renewable energy. Herein, the design and fabrication of innovative high performance binder-free electrodes consisting of coiled carbon nanotubes (CNTs) and biomass-derived hydrothermal carbon spheres (HTCSs) as, respectively, positive and negative electrodes is reported. High performance asymmetric supercapacitors (ASCs) were developed using novel 3D core/shell-like binary Ni-Co oxide (NCO) decorated coiled CNTs directly grown on Ni nano-cone arrays (NCAs) and HTCSs directly deposited on NCAs. Novel 3D structures of... 

Imidazolium-based ionic liquids (ILs) have been perceived as a promising candidate for bridging polyaniline (PANI) on well-dispersed carbon nanotubes (CNTs) via formation of IL-stabilized multiwalled carbon nanotubes (MWCNTs) dispersion in which outer walls of CNTs, as well as benzene rings of the aniline monomer and the growing polymer, have been potently effective in such procurement. The sulfonated water-soluble PANI-[C16C1im]Cl-MWCNT nanocomposites (SPANI-IL-MWCNTs) are directly deposited on a graphite-based current collector using a simple and cost-effective electrophoretic deposition (EPD) method. The SPANI-IL-MWCNT electrodes exhibit remarkable electrochemical performance compared to... 

Development of renewable energies is in parallel with improving high-performance energy storage devices, which can store maximum solar or wind energy and power. Herein, asymmetric energy storage systems are constructed from phosphorus-doped nickel sulfide (P-doped NiS) and biomass-derived humic acid (HA) as positive and negative electrodes, respectively. Initially, nickel sulfide (NiS) nanostructures are directly grown onto nickel foam (NF) via a hydrothermal step. P-doping into the NiS bulk is carried out through a simple hydrothermal process as well. Also, HA is activated via carbonization treatment (A-HA) for employing as the negative electrode's active material. The P-doped NiS-NF... 

Here, the effect of three different ionic liquids (IL) on the structural properties and photocatalytic activity of Bismuth Vanadate (BiVO4) was investigated. In this regard, BiVO4 hydrothermally synthesized in the presence of three different ionic liquids, including 2-hydroxyethyl ammonium formate, 1-Ethyl-3-methylimidazolium ethyl sulfate [Emim][EtSO4], and 1-Butyl-3-methylimidazolium methanesulfonate, [C4mim][MeSO3]. Additionally, the effect of calcination temperature was also studied by calcining hydrothermally synthesized BiVO4 at 600 °C, and all results were compared to a pure sample containing no IL. According to the characterization results, monoclinic scheelite-phase BiVO4 was only... 

We hereby demonstrate symmetric and asymmetric supercapacitors (SSCs and ASCs) based on core/shell-like Ni-Co oxide@cotton//Fe2O3-carbon nanotubes@cotton that are capable of storing a remarkable amount of energy, while retaining a high power density and long cycle life. Hierarchical, porous structures of Ni-Co-O nano-rod (NR) decorated Pd-activated cotton fibers (CFs) were fabricated using an eco-benign hydrothermal method and directly used as the cathode of the supercapacitors. Fe2O3-single-wall carbon nanotube (SWCNT) decorated CFs were employed as anodes of the fabricated ASCs. The assembled Ni-Co-O@cotton//Fe2O3-SWCNTs@cotton based ASCs possessed the benefits of a relatively high energy... 

High-performance textile-based energy storage systems with high energy and power densities alongside remarkable cyclic life are always at the leading edge of wearable electronics. Herein, commercial cotton fabrics (CCFs) are used as the substrates for the fabrication of ultra-light, high-performance wearable supercapacitors. Hierarchical microstructures of nickel-cobalt sulfide (Ni-Co-S) decorated single-walled carbon nanotubes (SWCNTs) are used as the positive supercapacitor electrodes. Enhanced electrochemical performance with a specific gravimetric capacity of 331 Cg−1 (at a current density of 0.3 Ag−1) is obtained from these Ni-Co-S@SWCNT@CCF electrodes. Besides, composites of graphene... 

High-performance supercapacitors that merit superior power and energy densities, as well as long-term cycle durability are always of great significance as a building block of energy storage devices. Herein, an innovative strategy is developed to design hierarchical and unique porous structures of ternary metal sulfide nano-flake decorated porous hydrothermal carbon microspheres. Hierarchical microspheres of ternary zinc-cobalt sulfide nanosheet (NS) decorated biomass derived hydrothermal carbon spheres (HTCSs) are directly employed as the positive supercapacitor electrodes. In addition, composites of pyrolyzed polyaniline nanotubes (PPNTs) and iron oxide, receiving advantages from highly... 

Flexibility and human-body compatibility have been emerged through the use of commercial fabrics (CFs) in designing wearable non-enzymatic glucose sensing platforms. In this work, electrodes fabricated through direct synthesis of ternary nickel–cobalt sulfide nanostructures (Ni-Co-S NSs) on the CFs (Ni-Co-S@CFs) using a fast and facile one-step microwave-assisted method for this purpose. Fabrication was followed by the structural and electrochemical characterization of the electrodes. The glucose-sensing ability of the prepared wearable electrodes was investigated via cyclic voltammetry (CV) and amperometry techniques in alkaline media. Two linear-responses in wide detection ranges of... 

Progression in the renewable energy field is tied to the development of high-performance energy storage devices with superior power and energy densities. Herein, an innovative material design was employed to prepare binder-free nickel-cobalt sulfide (NCS) on niobium pentoxide (Nb2O5)-decorated carbon spheres (CSs). Initially, CSs were directly grown on nickel foam (NF) via a hydrothermal carbonization approach. Core/shell-like NCS@Nb2O5@CS-NF was then synthesized through a hydrothermal process, followed by an electrodeposition process. When employed as an electrode material, NCS@Nb2O5@CS-NF achieved an excellent volumetric capacity of 9300 C L−1 at a current density of 18 A L−1. Later, an... 

Having a prime significance in diagonsing and predicting the dangerous symptoms of chronic diseases in the early stages, special attention has been drawn by wearable glucose-sensing platforms in recent years. Herein, modified commercial cotton fabrics, decorated with binary Ni–Co metal-organic frameworks (NC-MOFs) through a one-pot scalable hydrothermal route, were directly utilized as flexible electrodes for non-enzymatic glucose amperometric sensing. Glucose sensitivities of 105.2 μA mM−1 cm−2 and 23 μA mM−1 cm−2 were acheived within two distinct linear dynamic ranges of 0.04–3.13 mM and 3.63–8.28 mM, respectively. Receiving benefits from a remarkable glucose sensitivity behavior in... 

In this paper, we propose and compare various approaches of feature and decision fusion for human action classification in a multi-view framework. The key difference between the employed methods is in the nature of extracted features in each view and the stage we fuse data from all cameras to classify the activity. At the feature extraction stage we utilize three different methods. At the decision making stage, the features obtained by the cameras are combined in a single classifier, or a classifier for each camera produces a local decision which is combined with decisions from other cameras for a global decision. We have employed our method on a fall detection dataset, and all the fusion... 

Comparison of the traditional linear heating method of TPD with an original stepwise heating scheme was reported for the first time. Stepwise heating TPD was carried out by keeping the temperature constant as soon as ammonia desorption signal rises until the signal returns to the baseline. More ammonia desorption peaks on a SAPO-34 catalyst were identified using TPD with stepwise heating. The effect of temperature ramp on desorption peak broadening in TPD curve was also addressed. The more distinct ammonia desorption peaks in stepwise TPD indicates that ammonia adsorbs in about five or six different ways on SAPO-34, and attribution of different adsorptions may be explained considering some... 

Most part of Iran is dominated by arid and semi-arid areas due to low annual rainfall. The need for production of fresh water from brackish water is considerably high, especially in dry regions. In this study 1 month daily-based experimental data from a solar still site has been reported. The technical and operational problems of this site which finally contributed to the total cease of the site are described. Then a detailed analysis is investigated on progress of a prototype which constructed in order to solve the site's problems. The results of 1 month of experimental data of the final design showed that the last prototype could be used to solve the current problems of the site. The... 

Hydrocracking is one of the most versatile petroleum refining processes for production of valuable products including gasoline, gas oil, and jet fuel. In this paper, a five-parameter continuous lumping model was used for kinetic modeling of hydrocracking of vacuum gas oil (VGO). The model parameters were estimated from industrial data obtained from a fixed bed reactor operating at an average temperature of 400°C and residence time of 0.3 h. Product distributions were obtained in terms of the weight fraction of various boiling point cuts. The model parameters were estimated using the Nelder-Mead optimization procedure and were correlated with temperature. Comparison of experimental and... 

Purpose - The purpose of this paper is to present an improved methodology for design of custom-made hip prostheses, through integration of advanced image processing, computer aided design (CAD) and additive manufacturing (AM) technologies. Design/methodology/approach - The proposed methodology for design of custom-made hip prostheses is based on an independent design criterion for each of the intra-medullary and extra-medullary portions of the prosthesis. The intra-medullar part of the prosthesis is designed using a more accurate and detailed description of the 3D geometry of the femoral intra-medullary cavity, including the septum calcar ridge, so that an improved fill and fit performance...