Sharif Digital Repository

The coloring of hypergraph and its special case Steiner triple systems, STS(v), is studied extensively. But the defining set of the coloring of hypergraph even its special case STS(v), has not been explored yet. We study minimum defining set and the largest minimal defining set for 3-coloring of STS(v). We determined minimum defining set and the largest minimal defining set, for all non-isomorphic STS(v), v £ 15. Also we have found the defining number for all Steiner triple systems of order v, and some lower bounds for the size of the largest minimal defining set for all Steiner triple systems of order v, for each admissible v. © 2021 Taru Publications  

The coloring of hypergraph and its special case Steiner triple systems, STS(v), is studied extensively. But the defining set of the coloring of hypergraph even its special case STS(v), has not been explored yet. We study minimum defining set and the largest minimal defining set for 3-coloring of STS(v). We determined minimum defining set and the largest minimal defining set, for all non-isomorphic STS(v), v £ 15. Also we have found the defining number for all Steiner triple systems of order v, and some lower bounds for the size of the largest minimal defining set for all Steiner triple systems of order v, for each admissible v. © 2022 Taru Publications  

The problem of compliance checking and assessment is to ensure that the design or implementation of a system meets some desired properties and complies with some rules or regularities. This problem is a key issue in several human and engineering application domains such as organizational management and e-governance, software and IT industries, and software and systems quality engineering. To deal with this problem, some different approaches and methods have been proposed. In addition to the approaches such as formal methods, mathematical proofs, and logical evaluations, benchmarking can be used for compliance assessment. Naturally, a set of benchmarks can shape an applied solution to... 

A novel, magnetic nanocarrier was successfully synthesized through a facile and economical producer in which Fe3O4 magnetic nanoparticles were coated by starch-g-poly (methyl methacrylate-co-PEG-acrylamide). The surface of nanocarrier was then modified by hydrazine to preparation of a pH-responsive carrier. The resulted nanocarrier was applied for delivery of doxorubicin (DOX) as an effective anti-cancer drug. DOX was reacted with hydrazine linkage on the surface of nanocarrier to form hydrazone bond. Due to the presence of numerous hydrazine groups on the surface of magnetic nanocarrier large amounts of DOX was loaded onto the carrier (327 mg g−1). © 2016 The Korean Society of Industrial... 

Objective: This study analyzes the effects of lifestyle, nutrition, and diets on the status and risks of apparent (symptomatic) COVID-19 infection in Iranian families. Materials and Methods: A relatively extensive questionnaire survey was conducted on more than 20,000 Iranian families (residing in more than 1000 different urban and rural areas in the Islamic Republic of Iran) to collect the big data of COVID-19 and develop a lifestyle dataset. The collected big data included the records of lifestyle effects (e.g. nutrition, water consumption resources, physical exercise, smoking, age, gender, health and disease factors, etc.) on the status of COVID-19 infection in families (i.e. residents of... 

Molecular dynamics (MD) simulations were used to study the mechanical behaviour of β-SiC at nano-scale under tensile loading. Effects of loading rate and tensile temperature on the mechanical properties and failure were studied. Modified embedded-atom method (MEAM) potential and Berendsen thermostat were utilized for modelling. Periodic boundary conditions were employed and the behaviour of material was analyzed under three-axial loading condition at which the stress–strain relation was acceptably size independent. It is shown that with increasing the loading rate from 5 m/s to 70 m/s, the failure strain increases without a remarkable change in the stress–strain relationship. The MD... 

An efficient algorithm for the design optimization of the compressible fluid flow problem through a flexible structure is presented. The methodology has three essential parts: first the behavior of compressible flow in a supersonic diffuser was studied numerically in quasi-one-dimensional form using a flux splitting method. Second, a fully coupled sequential iterative procedure was used to solve the steady state aeroelastic problem of a flexible wall diffuser. Finally, a robust Genetic Algorithm was implemented and used to calculate the optimum shape of the flexible wall diffuser for a prescribed pressure distribution. © 2006 Elsevier Ltd. All rights reserved  

A novel heterogeneous catalyst has been synthesized based on the distillation-precipitation-polymerization of methyl acrylate onto modified magnetic nanoparticles followed by the amidation of the methyl ester groups using N,N-dimethylethylenediamine. The resulting poly(dimethylaminoethyl acrylamide) coated magnetic nanoparticles (MNP@PDMA) catalyst was characterized using an array of sophisticated analytical techniques, including FT-IR, TGA, SEM, TEM, CHN, vibrating sample magnetometer (VSM), and XRD analysis. The resulting heterogeneous base catalyst allowed the performance of a domino Knoevenagel condensation/Michael addition/cycloaddition reaction toward the synthesis of... 

Anchoring of copper sulfate in layered poly(imidazole-imidazolium) coated magnetic nanoparticles provided a highly stable, active, reusable, high loading, and green catalyst for the click synthesis of 1,2,3-triazoles via a one-pot cycloaddition of alkyl halide, azide, and alkyne (Cu-A3C). The catalyst was characterized by FTIR, TGA, TEM, SEM, XRD, EDAX, VSM and AAS. High selectivity, broad diversity of alkyl/benzyl bromide/chloride and alkyl/aryl terminal alkynes, and good to excellent yields of products were obtained using 0.7 mol% catalyst. The catalyst was readily recovered and reused up to 6 times without significant loss of activity  

The chromatic number of a Latin square is the least number of partial transversals which cover its cells. This is just the chromatic number of its associated Latin square graph. Although Latin square graphs have been widely studied as strongly regular graphs, their chromatic numbers appear to be unexplored. We determine the chromatic number of a circulant Latin square, and find bounds for some other classes of Latin squares. With a computer, we find the chromatic number for all main classes of Latin squares of order at most eight  

In this paper, recurrent neural networks are applied to language modeling of Persian, using word embedding as word representation. To this aim, unidirectional and bidirectional Long Short-Term Memory (LSTM) networks are used, and the perplexity of Persian language models on a 100-million-word data set is evaluated. The effect of various parameters, including number of hidden layers and size of LSTM units, on the performance of the networks in reducing the perplexity of the models are investigated. Among different LSTM language models, the best perplexity, which is equal to 59.05, is achieved from a 2-layer bidirectional LSTM model. Comparing this value with the perplexity of the classical... 

A heterogeneous magnetic copper catalyst was prepared via anchoring of copper sulfate onto multi-layered poly(2-dimethylaminoethyl acrylamide)-coated magnetic nanoparticles and was characterized using various techniques. The catalyst was found to be active, effective and selective for one-pot three-component reaction of alkyl halide, sodium azide and alkyne, known as copper-catalyzed click synthesis of 1,2,3-triazoles. As little as 0.3 mol% of catalyst was found to be effective under the optimum conditions. The catalyst could also be recycled and reused up to seven times without significant loss of activity. Thermal stability, high loading level of copper on catalyst, broad diversity of... 

A magnetic nanocomposite was prepared by entrapment of Fe3O4 nanoparticles into the cross-linked ionic liquid/epoxy type polymer. The resulting support was used for covalent immobilization of cellulase through the reaction with epoxy groups. The ionic surface of the support improved the adsorption of enzyme, and a large amount of enzyme (106.1 mg/g) was loaded onto the support surface. The effect of the presence of ionic monomer and covalent binding of enzyme was also investigated. The structure of support was characterized by various instruments such as FT-IR, TGA, VSM, XRD, TEM, SEM, and DLS. The activity and stability of immobilized cellulase were investigated in the prepared support. The... 

Molecular dynamics (MD) simulations were used to study the mechanical behaviour of β-SiC at nano-scale under tensile loading. Effects of loading rate and tensile temperature on the mechanical properties and failure were studied. Modified embedded-atom method (MEAM) potential and Berendsen thermostat were utilized for modelling. Periodic boundary conditions were employed and the behaviour of material was analyzed under three-axial loading condition at which the stress- strain relation was acceptably size independent. It is shown that with increasing the loading rate from 5 m/s to 70 m/s, the failure strain increases without a remarkable change in the stress-strain relationship. The MD... 

A heterogeneous tungstate-based catalyst has been prepared for selective oxidation of sulfides to sulfoxides in the presence of 30% H2O2. The catalyst was prepared via immobilization of high amounts of WO4 2− onto the cross-linked poly(ammonium ethyl acrylamide) coated magnetic nanoparticles (MNP). FT-IR, TEM, TGA, VSM, XRD, EDX, and CHN analysis were used for characterization of catalyst. Variety of sulfides successfully converted to the related sulfoxides using 1 mol% of catalyst at room temperature in high yields. The catalyst was easily recovered and reused up to 6 times without loss of activity