Sharif Digital Repository

Herein, Kiwi peel activated carbon (AC), Materials Institute Lavoisier (MIL-88B (Fe), and AC/MIL-88B (Fe) composite were synthesized and used as catalysts to degrade Reactive Red 198. The material properties were analyzed by the FTIR, BET-BJH, XRD, FESEM, EDX, TGA, and UV–Vis/DRS. The BET surface area of AC, MIL-88B (Fe) and AC/MIL-88B (Fe) was 1113.3, 150.7, and 199.4 m2/g, respectively. The band gap values (Eg) estimated by Tauc plot method, were obtained 5.06, 4.19 and 3.79 eV for AC, MIL-88B (Fe) and AC/MIL-88B (Fe), respectively. The results indicated that the AC/MIL-88B (Fe) composite had higher photocatalytic activity (99%) than that of pure AC (79%) and MIL-88B (Fe) catalysts (87%).... 

Discretization of spatial derivatives is an important issue in meshfree methods especially when the derivative terms contain non-linear coefficients. In this paper, various methods used for discretization of second-order spatial derivatives are investigated in the context of Smoothed Particle Hydrodynamics. Three popular forms (i.e."double summation","second-order kernel derivation", and"difference scheme") are studied using one-dimensional unsteady heat conduction equation. To assess these schemes, transient response to a step function initial condition is considered. Due to parabolic nature of the heat equation, one can expect smooth and monotone solutions. It is shown, however in this... 

This article proposes a novel index along with a user-friendly platform for resilience evaluation of the urban water distribution networks (WDN). WDN is of great importance in preserving the safety and sustainability of communities and cities. Resilience of a given system results in its sustainability. In recent years, many studies have focused on resilient urban WDN. However, these studies did not provide a comprehensive evaluation index and platform that could simultaneously consider hydraulic analysis, resilience parameters, and significant uncertainties. In this study, a novel resilience index was defined, and a user-friendly and practical platform (REWAT) was developed to calculate the... 

There is a need to find cheaper and simpler techniques for rural water filtration system in developing countries. Using a filter made of blocks for the water treatment enables one to make vertical filters. It is expected that the amount of land utilized would decrease by more than 70 % if vertical filters were used. The operation and washing would be simpler than using horizontal sand filters as filters made of blocks would be used instead. The feasibility study focused on finding adequate materials, compositions and methods of making a block with enough resistance to water pressure, sufficient porosity for water transformation, and using inexpensive, readily available materials. A pilot... 

Kernel based methods are significantly important in the pattern classification problem, especially when different classes are not linearly separable. In this paper, we propose a new kernel, which is the modified version of the polynomial kernel. The free parameter (d) of the proposed kernel considerably affects the error rate of the classifier. Thus, we present a new algorithm based on the Fisher criterion to find the optimum value of d. Simulation results show that using the proposed kernel for classification leads to satisfactory results. In our simulation in most cases the proposed method outperforms the classification using the polynomial kernel  

An improved incompressible smoothed particle hydrodynamics (ISPH) method is presented, which employs first-order consistent discretization schemes both for the first-order and second-order spatial derivatives. A recently introduced wall boundary condition is implemented in the context of ISPH method, which does not rely on using dummy particles and, as a result, can be applied more efficiently and with less computational complexity. To assess the accuracy and computational efficiency of this improved ISPH method, a number of two-dimensional incompressible laminar internal flow benchmark problems are solved and the results are compared with available analytical solutions and numerical data.... 

VO2(picolinichydrazone) complex as a catalyst was stabilized on a SBA-15 mesoporous silica as a catalytic support by using (3-chloropropyl)triethoxysilane as a connector. SBA-15 is nanoporous and has a high ratio of surface area to volume. The immobilization of a metal–Schiff base complex to the surface area of SBA-15 can improve its catalytic effects by increasing the catalytic surface area. Unlike homogeneous catalysts, heterogeneous catalysts can be recovered and reused several times without any significant loss of catalytic activity. A vanadium–Schiff base complex-functionalized SBA-15 was synthesized by covalency connected by a pre-synthesised VO2(picolinichydrazone) complex to... 

Objective: To translate the Foot and Ankle Ability Measure (FAAM) into Persian and to evaluate the psychometric properties of the Persian version of FAAM. Methods: 93 patients with a range of foot and ankle disorders, completed the Persian version of the FAAM and Short-Form 36 Health Survey (SF-36) in the test session. With an interval of 2-6 days, 60 patients filled out the FAAM in the retest session. The FAAM is composed of two subscales including activities of daily living (ADL) and SPORTS. Internal consistency was assessed using Cronbach's alpha, test-retest reliability using intraclass correlation coefficient (ICC) and standard error of measurement (s.e.m.), item internal consistency... 

Apathy is a stressor and debilitating common condition for both stroke survivors and their caregivers. However, its effects on the postural control of these patients have not yet been investigated. Improved postural stability through withdrawing attention from postural control by concurrent cognitive task (i.e. dual-task condition) has been reported previously, but the effect of apathy, as a confounding factor, remains unknown. This study aimed to examine the effects of apathy and dual-task condition on postural control of chronic stroke survivors from biomechanical and neurophysiological perspectives. Twenty non-apathetic stroke survivors, 20 apathetic stroke survivors, and 20 sex-, age-,... 

This paper presents a neuro-based approach for annual transport energy demand forecasting by several socio-economic indicators. In order to analyze the influence of economic and social indicators on the transport energy demand, gross domestic product (GDP), population and total number of vehicles are selected. This approach is structured as a hierarchical artificial neural networks (ANNs) model based on the supervised multi-layer perceptron (MLP), trained with the back-propagation (BP) algorithm. This hierarchical ANNs model is designed properly. The input variables are transport energy demand in the last year, GDP, population and total number of vehicles. The output variable is the energy... 

Rolling-element bearing (REB) Failure is one of the most common failure in rotary machines in industry. Therefore, this concern draws attention to the concept of diagnostic and the prediction of REB failure. The efficacy of vibration analysis in this area has led many researchers to focus on this topic in recent decades. Defective bearings such as fatigue, surface roughness, and corrosion can lead to disastrous accidents. Therefore, providing an algorithm for the detection and classification of bearing defects is valuable and useful. The prediction of the bearing's lifetime is important to ensure the planned production in an industrial unit. In this paper, different models for performance... 

Freezing of gait (FOG) is a debilitating symptom in patients with Parkinson's disease (PD), which may be associated with motor control impairments in tasks other than gait. This study aimed to examine whether symmetric and asymmetric bimanual coordination is impaired in PD with FOG (PD +FOG) patients and whether dual-task and drug phases may affect bimanual coordination in these patients. Twenty PD +FOG patients, 20 PD patients without FOG (PD –FOG) performed symmetric and asymmetric functional bimanual tasks (reach to and pick up a box and open a drawer to press a pushbutton inside it, respectively) under single-task and dual-task conditions. PD patients were evaluated during on- and... 

Recently, IoT has been massively applied in different areas of human life. Meanwhile, in many of the IoT applications, e.g., the remote patient health-care monitoring systems, the reliability of communications, and the consumed energy in IoT devices, which are mostly battery-operated, are very challenging. Since IoT devices are typically operated in lossy environments, providing a reliable transmission for the packets imposes a noticeable amount of energy consumption. In addition, the runtime movement of the IoT devices in mobile networks further intensifies these issues. Therefore, the applied policies in the IPv6 RPL as the standard routing mechanism in IoT networks, play an important role... 

Although anxiety is one of the most prevalent psychological disorders in stroke survivors, its effect on sensory reweighting has not yet been fully studied. The aim of this work was to investigate how anticipation of collision avoidance events affects sensory reweighting in chronic stroke survivors with low and high levels of anxiety (LA-stroke and HA-stroke, respectively), as compared with healthy controls (HC), under the condition of perturbed proprioception. Eighteen LA-stroke and 18 HA-stroke survivors, as well as 18 gender- and age-matched HC, participated in this study. Postural sway variability (i.e. Root Mean Square (RMS) of the COP velocity) was measured for a duration of 180 s... 

Anxiety is among the most debilitating nonmotor symptoms of Parkinson's disease (PD). This study aimed to determine how PD patients with low and high levels of anxiety (LA-PD and HA-PD, respectively) compare with age- and sex-matched controls at the level of motor control of reach-to-grasp movements during single- and dual-task conditions with varying complexity. Reach-to-grasp movement kinematics were assessed in 20 LA-PD, 20 HA-PD, and 20 sex- and age-matched healthy controls under single- as well as easy and difficult dual-task conditions. Assessment of PD patients was performed during both the on- and off-drug phases. The results obtained during dual-task conditions reveal deficits in... 

Objectives: To investigate the effects of competitive and noncompetitive volleyball exercises on the functional performance and motor control of the upper limbs in chronic stroke survivors. Design: Randomized clinical trial. Setting: Outpatient rehabilitation center. Participants: Chronic stroke survivors (N=48). Interventions: Participants were randomly assigned to competitive (n=16) or noncompetitive (n=16) volleyball exercise groups (60min/d volleyball exercise+30min/d traditional rehabilitation, 3d/wk for 7wk) and control group (n=16). Main Outcome Measures: Reach and grasp motor control measures were evaluated through kinematic analysis. Functional outcomes were assessed via Motor... 

Recent researches on automatic skill acquisition in reinforcement learning have focused on subgoal discovery methods. Among them, algorithms based on graph partitioning have achieved higher performance. In this paper, we propose a new automatic skill acquisition framework based on graph partitioning approach. The main steps of this framework are identifying subgoals and discovering useful skills. We propose two subgoal discovery algorithms, which use spectral analysis on the transition graph of the learning agent. The first proposed algorithm, incorporates k′-means algorithm with spectral clustering. In the second algorithm, eigenvector centrality measure is utilized and options are... 

A novel sturdy multi-stage noise-shaping sigma-delta modulator that cancels the first-stage quantisation error at the output of the modulator is presented. Since any stage of the modulator has unity signal transfer function, the modulator would be very robust to circuit non-idealities such as finite op-amp gain. Furthermore, the signal processing timing issue in the critical paths of the proposed topology has been relaxed due to shifting the delay of the last integrator to the feedback path of the modulator. Moreover, this topology can be implemented in the circuit level by a fewer active blocks. Therefore, it practically would be suitable for low-voltage and low-oversampling applications.... 

This Paper presents a practical way to improve signal bandwidth and resolution in a Sturdy Multi-Stage Noise- Shaping (SMASH) sigma delta modulator. In this way, the processing timing issue in the critical paths of the proposed architecture has been relaxed due to the shifting delay of the modulator loop filter of each stage to the its feedback path. The proposed Unity-STF SMASH architecture, which is realized with several efficient techniques, would be robust to circuit non-idealities such as finite op-amp DC gain. Furthermore the topology can be implemented by a fewer active blocks, suitable it for low power, high operation speed applications. © 2006-2017 Asian Research Publishing Network...