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101.
Farhad Shahrokhi Ondrej Sýkora László A. Székely Imrich Vrt’o 《Discrete Applied Mathematics》2007,155(9):1106-1115
The k-planar crossing number of a graph is the minimum number of crossings of its edges over all possible drawings of the graph in k planes. We propose algorithms and methods for k-planar drawings of general graphs together with lower bound techniques. We give exact results for the k-planar crossing number of K2k+1,q, for k?2. We prove tight bounds for complete graphs. We also study the rectilinear k-planar crossing number. 相似文献
102.
Farhad M. E. Raiszadeh B. P. Lingaraj 《The Journal of the Operational Research Society》1986,37(10):937-942
In this paper, we present the results of a study of real-world applications of O.R./M.S. as seen in journals. Five leading journals in the field are surveyed, and real-world application articles are classified using a two dimensional framework consisting of orientation and decision. The orientation dimension separates strategically oriented applications with long-term implications and tactically oriented applications with medium- and short-term implications. The decision dimension refers to the type of decision in the application-largely structured or largely unstructured. The major O.R./M.S. topics are placed in the resulting four quadrants, and articles published in the four most recent volumes of the five journals are classified. Based on the results of this survey, the thrust and shortcomings of implementation research are discussed. Some measures for enhancing publication of field-based research are also proposed. 相似文献
103.
Mohammad Ali Zolfigol Farhad Shirini Arash Ghorbani Choghamarani Iraj Mohammadpoor-Baltork 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1709-1715
A combination of silica chloride and sodium nitrite in the presence of wet SiO 2 were used as an effective oxidizing agent for the oxidation of dihydropyridines to their corresponding pyridine derivatives under mild and heterogeneous conditions in moderate to excellent yields. 相似文献
104.
105.
A green, simple and eco‐friendly three‐component condensation for the synthesis of 1‐(benzothiazolylamino)methyl‐2‐naphthols using new magnetic nanoparticles formulated as Fe3O4@SiO2–ZrCl2‐MNPs is described. Considering the economic and environmental aspects, the method provides some advantages such as clean procedure, solvent‐free conditions, simple operation and work‐up, relatively short reaction times and high yields of the products. Moreover the introduced catalyst can be readily recovered up to 4 consecutive runs with consistent activity using an external magnet. 相似文献
106.
Chahkamali Farhad Omarzehi Faghihi Mohammad Reza Maghsoodlou Malek Taher 《Research on Chemical Intermediates》2016,42(12):8109-8117
Research on Chemical Intermediates - In the present work, an efficient and convenient one-pot multi-component reaction is reported for the synthesis of highly diversified piperidines by tandem... 相似文献
107.
Mehdi Sattari Farhad Gharagheizi Poorandokht Ilani-Kashkouli Amir H. Mohammadi Deresh Ramjugernath 《Journal of Thermal Analysis and Calorimetry》2014,115(2):1863-1882
In this communication, a new approach is presented which combines a group-contribution (GC) method approach with genetic function approximation (GFA) for the prediction of liquid heat capacities at constant pressure (C pL) for ionic liquids at atmospheric pressure. The proposed method can be used instead of complicated nonlinear modeling approaches like artificial neural networks and support vector machine. The NIST standard reference database was used to prepare a dataset for C pL data. The dataset comprised 82 ionic liquids and consisted of 3,726 experimental data points. The dataset was divided such that 80 % of the data were used as a training set, and 20 % as a validation and test set. GFA was used to select functional groups, from which the GC based model was developed. Statistical analysis of the model shows that it has an overall average absolute relative deviation of 1.68 %, coefficient of determination (R 2) of 0.990, and root mean square of error (RMSE) of 18.42 J mol?1 K?1. 相似文献
108.
Ali Khalafi-Nezhad Farhad Panahi Reza Yousefi Yasaman Gholamalipour Sina Sarrafi 《Journal of the Iranian Chemical Society》2014,11(4):1189-1196
An efficient procedure for the synthesis of phenacyl and benzyl azolium salts in 2,2,2-trifluoroethanol and 1,1,1,3,3,3-hexafluoroisopropanol as fluorous alcohols have been developed. This synthetic methodology has some advantages with the respect to yield, atom efficiency, solvent and reagents used and wastes generated when compared to the currently in use methods. Using this procedure, a range of phenacyl and benzyl azolium salts can be synthesized with good to excellent yields. The pure salts are separated from the reaction mixture by simple filtration and washing with dry ether. 相似文献
109.
110.
Farhad Salimi Shahab Ayatollahia 《Journal of Dispersion Science and Technology》2013,34(12):1690-1696
In this study, asphaltene deposition from crude oil on the pipe surface has been studied experimentally using a novel designed test loop. Washing technique is used to quantitatively measure the rate of asphaltene deposition during laminar flow in the steel pipe. The effects of oil velocity, asphaltene content, and surface temperature on the thickness of asphaltene deposition are investigated. The results show that the asphaltene deposition rate increases with increasing surface temperature, results in asphaltene content reduction of the flowing crude oil. As the oil velocity increases, less deposition was noticed on the surface of the pipe. Besides, thermal approach was applied to the experimental procedure which shows good agreements between the predicted thickness and the measured value from the test loop. 相似文献