Sharif Digital Repository

In this paper, we want to solve multi-objective robot path planning problem. A new elitist multi-objective approach is proposed to determine Pareto front based on coefficient of variation. Intelligent water drops (IWD) algorithm is generalized by this approach and as a new multi-objective IWD algorithm. We call our new algorithm CV-based MO-IWD. It tried to optimize two objectives: length and safety of the path. In the CV-based MO-IWD, we want to discover solutions as close to optimal Pareto solutions as possible and find solutions as diverse as possible in the obtained Pareto front. In this way, coefficient of variation of Pareto front is determined in each objective. Then, appropriate... 

Differentiating between real and fake news propagation through online social networks is an important issue in many applications. The time gap between the news release time and detection of its label is a significant step towards broadcasting the real information and avoiding the fake. Therefore, one of the challenging tasks in this area is to identify fake and real news in early stages of propagation. However, there is a tradeoff between minimizing the time gap and maximizing accuracy. Despite recent efforts in detection of fake news, there has been no significant work that explicitly incorporates early detection in its model. The proposed method utilizes recurrent neural networks with a... 

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... 

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  

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... 

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  

A novel bi-functional polymeric catalyst was synthesized by immobilization of tungstate anions onto the nitrogen rich poly(ionic liquid)/magnetic nanocomposite. The resulting catalyst has two types of catalytic sites: (i) immobilized WO4 anions with bis-imidazolium ionic liquid cation for selective oxidation of alcohols and (ii) basic amine groups for Knoevenagel condensation between produced aldehyde and malononitrile. Due to the polymeric nature of the catalyst, large amounts of tungstate and basic nitrogen groups were presented on the solid surface which led to a decrease in the applied catalyst mass for catalytic reaction. High catalytic activity and excellent selectivity of catalyst in... 

A novel magnetically recoverable catalyst was prepared in which magnetic nanoparticles (MNPs) were functionalized by bis-imidazolium tungstate ionic liquid molecules. The resulting catalyst was highly dispersible in water and selectively oxidized a wide range of alcohols and sulfides using H2O2 as a green oxidant. The catalyst was easily recovered and reused at least 5 times under the described reaction conditions without any significant loss of reactivity