Sharif Digital Repository

Application of residential demand response (DR) programs are currently realized up to a limited extent due to customers' difficulty in manually responding to the time-differentiated prices. As a solution, this paper proposes an automatic home load management (HLM) framework to achieve the household minimum payment as well as meet the operational constraints to provide customer's comfort. The projected HLM method controls on/off statuses of responsive appliances and the charging/discharging periods of plug-in hybrid electric vehicle (PHEV) and battery storage at home. This paper also studies the impacts of different time-varying tariffs, i.e., time of use (TOU), real time pricing (RTP), and... 

In this paper, based on three-dimensional phenomenological model and using a user-defined material subroutine mechanical behavior of shape memory alloy (SMA) wire ropes (or cables) and their components have been studied through implicit solution method in Abaqus software. Material parameters have been extracted using available experimental data and numerical simulations. Due to the convoluted geometry and interwire contact status within a cable, a finite element analysis is firstly performed for a 1 × 37 steel wire rope to validate modeling and mechanical interactions of a wire rope. Afterwards, superelastic and shape memory effect cables with different constructions (7 × 7 and 1 × 27) are... 

Interest in carbon nanomaterials for energy storage systems such as supercapacitors has enormously risen due to their attractive electrical conductivity, chemical inertness, and charge storage capacity. The reduction of graphitic oxide is a versatile procedure to prepare 3D graphene. Despite many green methods, the dynamics behind ultrafast thermal graphitization have remained elusive. Here, we demonstrate an effort to understand the graphitization mechanism of graphitic oxide under ultrafast thermal reduction induced by electromagnetic radiation and probably via Ar+ cation collisions. The low photon energy (10.5 μeV) locally removes oxygen functionalities and restores the π-conjugated... 

In this paper, we describe a carbon dioxide mineralization process and its associated solid products. These solid products include amorphous silica, iron hydroxides and magnesium carbonates. These products were subjected to various characterization tests, and the results are published here. It was found that the iron hydroxides from this process can have different crystalline properties, and their formation depended very much on the pH of the reaction conditions. Different forms of magnesium carbonate were also obtained, and the type of carbonate precipitated was found to be dependent on the carbonation temperature. Hydromagnesite was obtained mainly at low temperatures, while dypingite was... 

NiTi alloys have exhibited significant potential as a matrix of wear resistant composites. In this study, in order to examine the effect of starting materials on the wear performance of NiTi-based composites, both elemental Ni/Ti and prealloyed NiTi powders were used to fabricate NiTi-6wt% nano-Al2O3 composites using hot isostatic pressing (HIP). Nanoindentation and microhardness test results indicate that the composite samples produced from the elemental Ni/Ti powders exhibited higher hardness and lower pseudoelasticity properties than those of the samples fabricated from the prealloyed NiTi powders; this is attributed to the higher amount of... 

The availability of 7-9 GHz of unlicensed spectrum at 60 GHz, advances in low-cost silicon technology, and high interference rejection due to atmospheric loss make 60 GHz an ideal solution for future 4G/5G small-cell backhaul links, where multi-gigabit rates are required. In this article, we review the 60 GHz propagation properties, the practical technology limits, and the regulatory and regional environmental impacts to present a framework for the 60 GHz backhaul link design that translates the link requirements to the essential transmitter and receiver system parameters. This approach includes a preliminary design that generates the input data set for an optimization problem. Two physical... 

Let G be a graph on n vertices with r := [n/2] and let γ 1 ≥ · · · ≥ γ n be adjacency eigenvalues of G. Then the Ḧuckel energy of G, HE(G), is defined as [Equation presented] The concept of Hückel energy was introduced by Coulson as it gives a good approximation for the π-electron energy of molecular graphs. We obtain two upper bounds and a lower bound for HE(G). When n is even, it is shown that equality holds in both upper bounds if and only if G is a strongly regular graph with parameters (n, k, γ, μ) = (4t2 + 4t + 2, 2t2 + 3t + 1, t2 + 2t, t2 + 2t + 1), for positive integer t. Furthermore, we will give an infinite family of these strongly regular graph whose construction was communicated... 

The antisolvent method has been used extensively to induce the growth of high-quality perovskite layers for efficient solar cells. However, uncontrollable nucleation and crystallization increases the risk of formation of undesirable defects. Here, we report a facile way to control the nucleation and crystallization stages in perovskite formation by changing the temperature of chlorobenzene (CB) in the antisolvent method. When CB is injected on the spinning substrate with a precursor solution, CB temperature affects the nucleation process as well as the crystallization process. As the CB temperature increases, nuclei increase in size, leading to the formation of larger perovskite crystals... 

The paper illustrates an extended effective load model including the capacities and uncertainties of generators and transmission lines. The conventional effective load model only considers the uncertainties of generators. An extended ELDC (effective load duration curve) based on the effective load model is proposed in the paper. The proposed nodal ELDC is able to supply information on nodal indices for probabilistic production cost simulation and reliability evaluation at the load points in a power system. It is expected that the effective load model presented in the paper will prove useful in many problems dealing with nodal and decentralised operation and control of electric power systems... 

In order to achieve a hydrogen economy, developing widespread hydrogen supply systems are vitally important. A large number of technological options exist and are still in development for hydrogen production, storage, distribution., which cause various pathways for supplying hydrogen. Besides the technical factors, there are other effective parameters such as cost, operability, reliability, environmental impacts, safety and social implications that should be considered when assessing the different pathways as optimal and viable long-term alternatives. To aid this decision-making process, we have developed a generic optimization-based model for the long-range energy planning and design of... 

Silica nanoparticles, which have a broad range of sizes and specific surface features, have been used in many industrial applications. This study was conducted to synthesize monodispersed silica nanoparticles directly from tetraethyl orthosilicate (TEOS) with an alkaline catalyst (NH3) based on the sol–gel process and the Stöber method. A central composite design (CCD) is used to build a second-order (quadratic) model for the response variables without requiring a complete threelevel factorial experiment. The process was then optimized to achieve the minimum particle size with the lowest concentration of TEOS. Dynamic light scattering and scanning electron microscopy were used to analyze the... 

A Dynamic model of Homogeneous Charge Compression Ignition (HCCI), based on chemical kinetics principles and artificial intelligence, is developed. The model can rapidly predict the combustion probability, thermochemistry properties, and exact timing of the Start of Combustion (SOC). A realization function is developed on the basis of the Sandia National Laboratory chemical kinetics model, and GRI3.0 methane chemical mechanism. The inlet conditions are optimized by Genetic Algorithm (GA), so that combustion initiates and SOC timing posits in the desired crank angle. The best SOC timing to achieve higher performance and efficiency in HCCI engines is between 5 and 15 degrees crank angle (CAD)... 

In this paper, we consider a wireless cooperative network with a wireless-powered energy harvesting (EH) relay. The relay employs a time switching (TS) policy that switches between the EH and data decoding (DD) modes. Both energy and data buffers are kept at the relay to store the harvested energy and decoded data packets, respectively. In this paper, we derive static and dynamic TS policies that maximize the system throughput or minimize the average transmission delay. In particular, in the static policies, the EH or DD mode is selected with a pre-determined probability. In contrast, in a dynamic policy, the mode is selected dynamically according to the states of data and energy buffers. We... 

In the past decade, fuzzy logic has been widely used to manage uncertainty in games. In this paper, we employ fuzzy logic to determine the priority of a payoff using linguistic preference relation. Preferences are derived according to the difference between payoffs using fuzzy IF-THEN rule. We introduce the concept of linguistic Nash equilibrium based on priority of each payoff. We assign a fuzzy set type2 to each cell to determine how much a cell has possibility to have a specific degree of being Nash. © 2008 IEEE  

Thanks to recent developments in ride-hailing transit services throughout the world, the peer-to-peer (P2P) ride-matching problem has been actively considered in academia in recent years. P2P ride-matching not only reduces travel costs for riders but also benefits drivers by saving them money in exchange for their additional travel time. However, assigning riders to drivers in an efficient way is a complex problem that requires focusing on maximizing the benefits for both riders and drivers. This study aims to formulate a multi-driver multi-rider (MDMR) P2P ride-matching problem, based on rational preferences and cost allocation for both driver and rider, which also allows riders to transfer... 

Demand responsive feeder transit can minimize passengers’ travel times and operator's costs by optimizing routing based on real demand. One question about the demand response feeder transit operation is whether it can be optimized with door-to-door service or with temporary stops for picking up and delivering passengers. Obviously, door-to-door service eliminates passengers’ walking distances, but it increases passenger in-vehicle travel times and vehicle operating distance and costs. On the other hand, demand responsive feeder transit with temporary stops, which designates the temporary locations picking up and dropping passengers, minimizes bus operating distance and time as well as... 

Carbon dioxide sequestration by a pH-swing carbonation process was considered in this work. A multi-step aqueous process is described for the fractional precipitation of magnesium carbonate and other minerals in an aqueous system at room temperature and atmospheric pressure. With the aim to achieve higher purity and deliver more valuable mineral products, the process was split into four steps. The first step consists of Mg leaching from the magnesium silicate in a stirred vessel using 1 M HCl at 80 °C, followed by a three step precipitation in reactors in sequence to remove Fe(OH)3, then Fe(OH)2 and other divalent ions, and finally MgCO3 nucleation and growth. Hydrated magnesium carbonate... 

TiO2 thin films containing different concentrations of Ag nanoparticles have been synthesized by sol-gel method. According to UV-visible spectra, presence of an intense surface plasmon resonance peak at 490 nm of wavelength indicated formation of silver nanoparticles in the TiO2 films. Based on atomic force microscopy (AFM) analysis, the surface roughness and the effective surface ratio increased by increasing the Ag mol%. Moreover, scanning electron microscopy (SEM) images showed formation of Ag nanoparticles on the surface for the samples containing high Ag concentration. X-ray diffraction (XRD) patterns revealed that the size of Ag nanocrystals increased by increasing the Ag content in... 

WO3 thin film photoanodes containing different concentrations of Ag nanoparticles were synthesized by solegel method. Based on UV-visible spectra, presence of a surface plasmon resonance peak at 470 nm of wavelength indicated formation of silver nanoparticles in the WO3 films. According to atomic force microscopy (AFM) analysis, the highest value for surface roughness and the effective surface ratio was observed for the sample containing 2 mol% of Ag. X-ray diffraction (XRD) patterns revealed that WO 3 nanocrystalline structure was formed in the monoclinic phase with the average size of about 18.2 nm while Ag nanocrystals were determined in cubic phase. X-ray photoelectron spectroscopy (XPS)... 

Electrochemical co-deposition approach was expanded to prepare composite bio-ceramic coating of hydroxyapatite (HA)/polyvinyl acetate on the surface of titanium. The role is to improve the bioactive and crystallization properties. The results of XRD, XPS, SEM and TEM characterization showed that by increasing amount of vinyl acetate in the composite bio-ceramic coating before and after immersing in the simulated body fluid (SBF), an oriented growth of HA planes on the (0 0 2) direction had been observed on titanium substrate. Also significant surface morphology changes were obtained