Sharif Digital Repository

Volumetric and equilibrium calculations for the natural gas and oil defined by a large number of components are not feasible in applications like compositional reservoir simulation. Therefore, the fluid mixture is grouped to reduce computational load and to make faster calculations. However, for several reasons, it is required to have the detailed fluid composition rather than the lumped one. In this work, an improved delumping method is presented to retrieve the phase composition of the detailed mixture based on the grouped mixture thermodynamic calculations. The method is based on previously proposed delumping techniques for non-cubic equation of state (Assareh et al. in Fluid Phase... 

Protein mass spectra pattern recognition is a new forum in which many machine learning algorithms have been conducted to enhance the chance of early cancer diagnosis. The high-dimensionality-small-sample (HDSS) problem of cancer proteomic datasets still requires more sophisticated approaches to improve the classification accuracy. In this study we present a simple ensemble strategy based on measuring the generalizing capability of different subsets of training data and apply it in making final decision. Using a limited number of biomarkers along with 5 classification algorithms, the proposed method achieved a promising performance over a well-known prostate cancer mass spectroscopy dataset.... 

APS (3-Aminopropyl) trimethoxysilane) and APhS (p-Aminophenyl) trimethoxysilane) are the most commonly used linkers on a silicon surface. We investigate the surface properties of the structures, including APS or APhS on a silicon substrate. The studied structures consist of APS or APhS linkers with one, two, or three bonds with a substrate, which is a thin layer of Si with crystal orientation 〈1 0 0〉 or 〈1 1 1〉. Using a first-principles study based on density functional theory (DFT), we investigated the electronic and optical properties of the silicon-linker interface, such as interface states, orbital location, dielectric function, and photon absorption. The effects of linker type, number... 

Parameters of the PC-SAFT Equation of State (EoS) for pure components are generally determined by matching the saturation pressure and liquid density experimental data. These experimental data are unavailable for petroleum cuts and plus fractions of the petroleum reservoir fluids. In this work, new correlations as functions of specific gravity and molecular weight were developed to estimate the PC-SAFT parameters of petroleum cuts with unknown composition. It was shown that the proposed correlations accurately estimate the PC-SAFT parameters of the pure components published in the literature. Then, the obtained correlations were used and the PVT experimental data for various real reservoir... 

In this work, a new automatic workflow for accurate optimal pseudo-component generation from gas condensate mixtures with a large number of components is presented. This workflow has a good insight into thermo-physical and critical properties and introduces only a small amount of loss of information and EOS flexibility. In this regard, the fuzzy clustering is used to classify the components in the mixture based on the similarities in the critical properties. The mixing rules are then applied to find group properties. Two different approaches for components association in clustering process are investigated with several numbers of groups. The mathematical validity of the groups is controlled... 

The strong bases statistical associated fluid theory (SAFT) equations of state allow modeling for a wide range of scales and applications. The equilibrium calculations are very time-consuming in SAFT-based family of equations of state; therefore the number of components used in describing a fluid mixture must be reduced by grouping. On the other hand, in some applications it is required to retrieve the detailed fluid description from equilibrium calculation performed on the lumped fluid description. The purpose of this paper is to develop a systematic approach for lumping and delumping with equilibrium calculations using the Perturbed Chain (PC)-SAFT equation of state. The methodology... 

Various EEG features have been used in depth of anesthesia (DOA) studies. The objective of this study was to And the excellent features or combination of them than can discriminate between different anesthesia states. Conducting a clinical study on 22 patients we could define 4 distinct anesthetic states: awake, moderate, general anesthesia, and isoelectric. We examined features that have been used in earlier studies using single-channel EEG signal processing method. The maximum accuracy (99.02%) achieved using approximate entropy as the feature. Some other features could well discriminate a particular state of anesthesia. We could completely classify the patterns by means of 3 features and... 

Energy storage and supply in solar thermal collector systems rely heavily on phase change materials (PCM). It is vital to establish the appropriate values for energy discharge time (tPCM) and net amount of stored energy (Qnet) within the PCMs in order to increase the efficiency of solar thermal collectors. For this study, we implemented a multi-objective evolutionary algorithm based on decomposition (MOEA/D) for the optimization process using the MATLAB simulator software. The simulation findings show that, under ideal circumstances where tPCM is large and Qnet is low, these two goal functions are inversely connected to one another. According to an analysis of how input parameters affect the... 

In vivo dose-dependent effects of nanoscale graphene oxide (NGO) sheets on reproduction capability of Balb/C mice were investigated. Biodistribution study of the NGO sheets (intravenously injected into male mice at dose of ∼2000 μg/mL or 4 mg/kg of body weight) showed a high graphene uptake in testis. Hence, in vivo effects of the NGO sheets on important characteristics of spermatozoa (including their viability, morphology, kinetics, DNA damage and chromosomal aberration) were evaluated. Significant in vivo effects was found at the injected concentrations ≥200 μg/mL after (e.g., ∼45% reduction in sperm viability and motility at 2000 μg/mL). Observation of remarkable DNA fragmentations and... 

Asian red ginseng was used for green reduction of chemically exfoliated graphene oxide (GO) into reduced graphene oxide (rGO). The reduction level and electrical conductivity of the ginseng-rGO sheets were comparable to those of hydrazine-rGO ones. Reduction by ginseng resulted in repairing the sp 2 graphitic structure of the rGO, while hydrazine-rGO showed more defects and/or smaller aromatic domains. The ginseng-rGO sheets presented a better stability against aggregation than the hydrazine-rGO ones in an aqueous suspension. Whilst the hydrophobic hydrazine-rGO films exhibited no toxicity against human neural stem cells (hNSCs), the hydrophilic GO and ginseng-rGO films (as more... 

Vigorous debates have taken place within and between many countries about regulatory policy regimes covering the assessment and approval of genetically modified (GM) crops. In Iran, a very vigorous and hotly contested policy debate concerning legislation covering GM crops occurred between 2004 and 2009, but it was confined within government circles with almost no public discussion. This paper analyses the Iranian policy-making process in the period 2006-9. It explains how and why a stalemate arose in disputes between ministries and departments. The chosen analytical framework draws mainly on the regulation of technological risks and the analysis of public policy-making. It deploys the... 

A μ-way latin trade of volume s is a set of μ partial latin rectangles (of inconsequential size) containing exactly the same s filled cells, such that if cell (i, j) is filled, it contains a different entry in each of the μ partial latin rectangles, and such that row i in each of the μ partial latin rectangles contains, set-wise, the same symbols and column j, likewise. In this paper we show that all μ-way latin trades with sufficiently large volumes exist, and state some theorems on the non-existence of μ-way latin trades of certain volumes. We also find the set of possible volumes (that is, the volume spectrum) of μ-way latin trades for μ = 4 and 5. (The case μ = 2 was dealt with by Fu,... 

The set of integers k for which there exist three latin squares of order n having precisely k cells identical, with their remaining n2 -k cells different in all three latin squares, denoted by I3[n], is determined here for all orders n. In particular, it is shown that I3[n] = {0,.,n2 -15}U [n2 - 12,n2-9,n2], for n ≫8. ©2002 Eisevier Science B.V. All rights reserved  

Coronary angiography is a vital instrument to detect the prevailing of vascular diseases, and accurate vascular segmentation acts a crucial role for proper quantitative analysis of the vascular tree morphological features. Level set methods are popular for segmenting the coronary arteries, but their performance is related to suitable start-up and optimum setting of regulating parameters, essentially done manually. This research presents a novel fuzzy level set procedure with the objective of segmentation of the coronary artery tree in 2-D X-ray angiography as automatically. It is clever to clearly develop from the early segmentation with spatial fuzzy grouping. The adjusting parameters of... 

Visual attributes are great means of describing images or scenes, in a way both humans and computers understand. In order to establish a correspondence between images and to be able to compare the strength of each property between images, relative attributes were introduced. However, since their introduction, hand-crafted and engineered features were used to learn increasingly complex models for the problem of relative attributes. This limits the applicability of those methods for more realistic cases. We introduce a deep neural network architecture for the task of relative attribute prediction. A convolutional neural network (ConvNet) is adopted to learn the features by including an... 

We present the first public code for the calculation of the astrometric centroid shift occurring during microlensing events. The computation is based on the contour integration scheme and covers single and binary lensing of finite sources with arbitrary limb darkening profiles. This allows for general detailed investigations of the impact of finite source size in astrometric binary microlensing. The new code is embedded in version 3.0 of vbbinarylensing, which offers a powerful computational tool for extensive studies of microlensing data from current surveys and future space missions. © 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society  

The possibility of real-time tuning of optical devices has attracted a lot of interest over the last decade. At the same time, coming up with simple lithography-free structures has always been a challenge in the design of large-area compatible devices. In this work, we present the concept and the sample design of an electrically tunable, lithography-free, ultra-thin transmission-mode color filter, the spectrum of which continuously covers the whole visible region. A simple Metal-Insulator-Metal (MIM) cavity configuration is used. It is shown that using the electro-optic dielectric material of 4-dimethyl-amino-N-methyl-4-stilbazoliumtosylate (DAST) as the dielectric layer in this... 

Magnetic flux leakage is the most widely used method for oil and gas pipeline non destructive testing. The saturation level of the sample under test has a significant effect on its efficiency; therefore, the magnetizing yoke requires an elaborate design. The finite element method is the conventional approach used for this purpose, but it is very time consuming. In this article, a neuro-fuzzy method is presented to model the behavior of the magnetizing yoke. Modeling a few different designs with the finite element method and using the results for training the neuro-fuzzy model eradicates the necessity of modeling a huge number of designs with the finite element method. The acquired...