Sharif Digital Repository

A significant share of losses in power systems occurs in distribution network due to lower voltages and longer lines. On top of that, unbalanced operation causes additional losses in these networks. In recent years with the development of distributed generation connected to the distribution grid, the concern over frequency and intensity of unbalanced operation has risen. Reconfiguration of these distribution networks plays a significant role in power loss minimization and voltage quality enhancement. The uncertainty regarding grid-connected DG resources and net loads are among the critical factors that must be taken into account. To do so, in this paper a novel Fuzzy-based reconfiguration... 

Low-frequency O 2 plasma was used to modify the surface of polysulfone gas-separation membranes. The effects of the treatment time and plasma power input on the membranes were also investigated. Pure CO 2 and CH 4 gas-permeation measurements were performed before and after plasma treatment. The results show the increase of permeability of the treated membranes due to surface ablation and surface polarization up to 5.63 and 68.80 gas-permeation units for CH 4 and CO 2, respectively, whereas, the CO 2/CH 4 selectivity of the treated membranes varied from 7.7 to 45.3, depending on the treatment conditions. Attenuated total reflection-Fourier transform infrared spectroscopy determined the... 

This study aims to identify genetic causes of familial female infertility characterized by embryonic developmental arrest (EDA) and repeated implantation failure (RIF) with oocyte donation IVF cycle. We used Whole-exome sequencing and Sanger validation to find causative genes in an Iranian consanguineous family that had 3 infertile daughters, 4 fertile daughters, and 2 fertile sons. All patients in this consanguineous family exhibited typical manifestations of unexplained RIF and EDA. Genetic analysis identified a homozygous missense variant (c.G1054C:p.G352R) in exon 13 of the TLE6 gene that cosegregated with the EDA phenotype in an autosomal recessive pattern. Other members of the family,... 

Phase noise is one of the most important specifications of microwave oscillators. External factors such as mechanical vibrations increase the phase noise of the oscillator. A novel technique is introduced to reduce vibration-induced phase noise using inter-injection locking of two coupled oscillators. Two similar oscillators with equal free running frequencies are chosen and are subjected to sinusoidal vibration. The mechanical configuration is such that vibration sensitivity vector increases the frequency of one oscillator and decreases the other one's frequency of oscillation. Coupling these two oscillators using inter-injection locking, the common after-lock frequencies of both... 

This paper investigates the effects of service quality regulation on investing in distribution automation. Among different regulatory instruments for quality regulation, the Reward-Penalty Scheme (RPS) has been selected to evaluate the effect of monetary incentive on behavior of Electric Distribution Utility (EDU) for service reliability. By implementing different automation strategies, the value of enhancing reliability indices and consequently the value of rewards and penalties are calculated for each strategy. For achieving to more realistic outcome, ten years horizon is considered. Furthermore, in the calculation of reliability indices, the time varying failure rate of components is... 

This paper investigates the effects of service quality regulation on investing in distribution automation. Among different regulatory instruments for quality regulation, the Reward-Penalty Scheme (RPS) has been selected to evaluate the effect of monetary incentive on behavior of Electric Distribution Utility (EDU) for service reliability. By implementing different automation strategies, the value of enhancing reliability indices and consequently the value of rewards and penalties are calculated for each strategy. For achieving to more realistic outcome, ten years horizon is considered. Furthermore, in the calculation of reliability indices, the time varying failure rate of components is... 

This paper investigates the effects of service quality regulation on investing in distribution automation. Among different regulatory instruments for quality regulation, the Reward-Penalty Scheme (RPS) has been selected to evaluate the effect of monetary incentive on behavior of Electric Distribution Utility (EDU) for service reliability. By implementing different automation strategies, the value of enhancing reliability indices and consequently the value of rewards and penalties are calculated for each strategy. For achieving to more realistic outcome, ten years horizon is considered. Furthermore, in the calculation of reliability indices, the time varying failure rate of components is... 

This paper investigates the effects of service quality regulation on investing in distribution automation. Among different regulatory instruments for quality regulation, the Reward-Penalty Scheme (RPS) has been selected to evaluate the effect of monetary incentive on behavior of Electric Distribution Utility (EDU) for service reliability. By implementing different automation strategies, the value of enhancing reliability indices and consequently the value of rewards and penalties are calculated for each strategy. For achieving to more realistic outcome, ten years horizon is considered. Furthermore, in the calculation of reliability indices, the time varying failure rate of components is... 

Set of experiments has been developed to study existing runaway electrons in "Damavand" tokamak plasma upon characteristics of hard x-ray emissions produced by collision of the runaway electrons with the plasma particles and limiters. As a first step, spatial distribution of hard x-ray emissions on the equatorial plane of the torus was considered. Obtained spectra of hard x-ray emissions for different alignments of shielded detector indicate isotropic emissivity in the equatorial plane. This is in agreement with wide angle cone of bremsstrahlung radiations, deduced from the mean value of energy of the runaway electrons. The mean energy was calculated from the slope of the energy spectrum of... 

In this paper, we address global non-fragile control and synchronization of a new fractional order chaotic system. First we inspect the chaotic behavior of the fractional order system under study and also find the lowest order (2.49) for the introduced dynamics to remain chaotic. Then, a necessary and sufficient condition which can be easily extended to other fractional-order systems is proposed in terms of Linear Matrix Inequality (LMI) to check whether the candidate state feedback controller with parameter uncertainty can guarantee zero convergence of error or not. In addition, the proposed method provides a global zero attraction of error that guarantees stability around all existing... 

The first step to locate Partial Discharge in power transformers is to find a model that can clearly explain the behavior of the winding in high-frequency. The detailed model is one of the models used for the study of PD. One of the fundamental problems of the described model is to find its parameters. And the accuracy in calculating these parameters has significant impact on reducing the simulation error and PD locating. The current paper seeks to calculate the parameters of the detailed model 20kv distribution transformer winding by using the finite element method (FEM). Comparing the results of this model with pulse waveforms obtained from the PD to the winding in the laboratory... 

A single-degree-of-freedom model is considered for flexible exercise bars based on the lumped-element approach. By considering the side segment of a flexible bar as a cantilever beam with an equivalent mass at the free end, its free-vibration response, as well as the forced response under the excitation of the grip, are expressed parametrically. Experiments are performed on a particular flexible bar (FLEXI-BAR) in order to obtain numerical values for quantifying the model's parameters. The model is also computationally simulated to study the response of the flexible bar to various excitations. The results are imported into a multi-segment musculoskeletal software (AnyBody), where the effect... 

While the differentiation factors have been widely used to differentiate mesenchymal stem cells (MSCs) into various cell types, they can cause harm at the same time. Therefore, it is beneficial to propose methods to differentiate MSCs without factors. Herein, magnetoelectric (ME) nanofibers were synthesized as the scaffold for the growth of MSCs and their differentiation into neural cells without factors. This nanocomposite takes the advantage of the synergies of the magnetostrictive filler, CoFe 2 O 4 nanoparticles (CFO), and piezoelectric polymer, polyvinylidene difluoride (PVDF). Graphene oxide nanosheets were decorated with CFO nanoparticles for a proper dispersion in the polymer through... 

We have investigated the piezoelectric response of the hydrogenated graphene oxide (H-G-SiO2) stacks both experimentally and theoretically. The piezoresponse force microscopy method and density-functional theory (DFT) calculations were used to study the piezoresponse effect of this structure from both experimental and computational point of views. A mono-layer graphene, made by chemical vapour deposition method, is deposited on Si/SiO2 substrate and its surface is then functionalized with hydrogen atoms. The vertical piezoresponse, observed by piezoresponse force microscopy, is measured to be about 2146 pC N-1, that is comparable to the reported state of the art piezoelectric materials such... 

Design of an Ultra-Wideband 3-dB quadrature (90°) Hybrid using ADS and HFSS softwares plus Measurement report are presented. Simultaneous Use of these two softwares lead to fast and accurate design procedure. The coupler is realized in broadside stripline and with the connection of coupled regions in tandem structure. The measured data agrees well with the expected values from simulations, and shows a good ultra wide bandwidth response over the frequency range of 1-10 GHz. Measurements showed an amplitude unbalance of ±1.5 dB, a phase unbalance of 90°±7° , and an isolation and a return loss characteristics of more than 14 dB over the frequency of 1 to 10 GHz  

The Ni-base superalloy GTD-111 is employed in high-power stationary gas turbines because of its high temperature strength and oxidation resistance. The temperature dependence of the tensile behavior of GTD-111 has been studied by tensile tests in the temperature range of 25-900°C with a constant strain rate of 10-4s-1. The results showed an abnormal tensile property variation with increasing temperature. The yield strength decreased slightly with temperature up to about 650°C and then increased between 650 and 750°C. Above 750°C, a rapid decrease in the yield strength was found. The tensile strength showed a similar behavior except for its maximum that occurred at 650°C. The elongation... 

Bioinspired materials can mimic the stem cell environment and modulate stem cell differentiation and proliferation. In this study, biomimetic micro/nanoenvironments were fabricated by cell-imprinted substrates based on mature human keratinocyte morphological templates. The data obtained from atomic force microscopy and field emission scanning electron microscopy revealed that the keratinocyte-cell-imprinted poly(dimethylsiloxane) casting procedure could imitate the surface morphology of the plasma membrane, ranging from the nanoscale to the macroscale, which may provide the required topographical cell fingerprints to induce differentiation. Gene expression levels of the genes analyzed...