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Effect of graphene functionalizing on the performance of NiMo/graphene in HDS and HDN reactions

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Petroleum Science 2019年第5期16卷 1185-1195页

作者： Babak Behnejad majid Abdouss Ahmad Tavasoli Department of Chemistry Amirkabir University of TechnologyTehranIran School of Chemistry College of ScienceUniversity of TehranTehranIran

In this research,to remove sulfur and nitrogen compounds from heavy naphtha,various nanocatalysts were prepared through supporting NiMo over nanoporous graphene and evaluated in hydrodesulfurization and hydrodenitrogenation *** nanoporous graphene was initially functionalized in order to facilitate the metal being loaded on *** different methods were used to functionalize the nanoporous *** NiMo/nanoporous graphene nanocatalysts were characterized by field emission scanning electron microscopy,Fourier transform infrared spectroscopy,X-ray diffraction,inductively coupled plasma optical emission spectrometry,temperature-programmed reduction,nitrogen adsorption-desorption isotherms and transmission electron microscopy *** performance was evaluated in terms of conversions of sulfur,mercaptans(R-SH)and nitrogen *** was found that the functionalized nanoporous graphene support could significantly enhance the catalytic performance in comparison with the industrial NiMo/alumina *** the functionalized graphene supports,amine-functionalized graphene exhibited the best *** using NiMo supported over amine-functionalized graphene,the conversions of total sulfur and R-SH reached 97.8%and 98.1%,respectively.

关键词： Hydrodesulfurization(HDS) Hydrotreating(HDT) Nanocatalyst Catalyst support Graphene functionalization NiMo/nanoporous graphene

Vertex Cover Optimization Using a Novel Graph Decomposition Approach

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Computers, Materials & Continua 2022年第10期73卷 701-717页

作者： Abdul Manan Shahida Bashir Abdul majid Department of Mathematics University of GujratGujrat50700Pakistan Department of Physics University of GujratGujrat50700Pakistan

The minimum vertex cover problem(MVCP)is a well-known combinatorial optimization problem of graph *** MVCP is an NP(nondeterministic polynomial)complete problem and it has an exponential growing complexity with respect to the size of a *** algorithm exits till date that can exactly solve the problem in a deterministic polynomial time ***,several algorithms are proposed that solve the problem approximately in a short polynomial time *** algorithms are useful for large size graphs,for which exact solution of MVCP is impossible with current computational *** MVCP has a wide range of applications in the fields like bioinformatics,biochemistry,circuit design,electrical engineering,data aggregation,networking,internet traffic monitoring,pattern recognition,marketing and franchising *** work aims to solve the MVCP approximately by a novel graph decomposition *** decomposition of the graph yields a subgraph that contains edges shared by triangular edge structures.A subgraph is covered to yield a subgraph that forms one or more Hamiltonian cycles or *** order to reduce complexity of the algorithm a new strategy is also *** reduction strategy can be used for any algorithm solving *** on the graph decomposition and the reduction strategy,two algorithms are formulated to approximately solve the *** algorithms are tested using well known standard benchmark *** key feature of the results is a good approximate error ratio and improvement in optimum vertex cover values for few graphs.

关键词： Combinatorial optimization graph theory minimum vertex cover problem maximum independent set maximum degree greedy approach approximation algorithms benchmark instances

Evaluation of TIGGE Ensemble Forecasts of Precipitation in Distinct Climate Regions in Iran

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Advances in Atmospheric Sciences 2018年第4期35卷 457-468页

作者： Saleh AMINYAVARI Bahram SAGHAFIAN majid DELAVAR Department of Technical and Engineering Science and Research Branch Islamic Azad University Department of Water Resources Engineering Tarbiat Modares University

The application of numerical weather prediction （NWP） products is increasing dramatically. Existing reports indicate that ensemble predictions have better skill than deterministic forecasts. In this study, numerical ensemble precipitation forecasts in the TIGGE database were evaluated using deterministic, dichotomous （yes/no）, and probabilistic techniques over Iran for the period 2008-16. Thirteen rain gauges spread over eight homogeneous precipitation regimes were selected for evaluation. The Inverse Distance Weighting and Kriging methods were adopted for interpolation of the prediction values, downscaled to the stations at lead times of one to three days. To enhance the forecast quality, NWP values were post-processed via Bayesian Model Averaging. The results showed that ECMWF had better scores than other products. However, products of all centers underestimated precipitation in high precipitation regions while overestimating precipitation in other regions. This points to a systematic bias in forecasts and demands application of bias correction techniques. Based on dichotomous evaluation, NCEP did better at most stations, although all centers overpredicted the number of precipitation events. Compared to those of ECMWF and NCER UKMO yielded higher scores in mountainous regions, but performed poorly at other selected stations. Furthermore, the evaluations showed that all centers had better skill in wet than in dry seasons. The quality of post-processed predictions was better than those of the raw predictions. In conclusion, the accuracy of the NWP predictions made by the selected centers could be classified as medium over Iran, while post-processing of predictions is recommended to improve the quality.

关键词： ensemble forecast NWP TIGGE evaluation post-processing

Holistic Approach to Functional Constipation: Perspective of Traditional Persian Medicine

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Chinese Journal of Integrative Medicine 2019年第11期25卷 867-872页

作者： majid Nimrouzi Mohammad M. Zarshenas Esse nee of Parsiyan Wisdom Institute Traditional Medici ne and Medicinal Plant IncubatorShiraz University of Medical SciencesShirazIran Research Center for Traditional Medicine and History of Medicine Shiraz University of Medical SciencesShirazIran Department of Traditional Pharmacy School of PharmacyShiraz University of Medical SciencesShirazIran

Traditional Persian medicine(TPM) proposes a different viewpoint to the chronic diseases. Diagnosis and implemented treatment are based on individual differences among patients. Constipation or Ea’teghal-e-batn is a condition in which the patient develops difficult or painful defecation. Based on TPM concepts, the first digestion step starts from halq(oral cavity), and ends via defecation from the maq’ad(anus). Avicenna believed that four faculties, ha’zemeh(digestive), ja’zebeh(absorptive), ma’sekeh(retentive) and da’fe’eh(propulsive), are involved in the process of digestion and absorption of the ingested food and expelling the waste materials. The bowel movement and appearance of the stool is a measure for evaluating the gastrointestinal healthy function. Defecation should be with no pain and fecal material should have no burning and acuity. Low food intake or foods with dry temperament, dryness of gastrointestinal tract, diaphoresis and heavy exercise as well as intestine sensory loss were discussed as main causes of constipation. Management of constipation in TPM includes dietary schemes, oil massages and subsequently simple herbal medicines. According to TPM theories, the first step in treating a disease is the elimination of disease causes(asbabe-maraz) and also providing the causes of health(asbab-e-sehhat). Health care providers should know the proper condition which the herbal medicines should be administered in and be able to guide the patients about the benefits and hazards of herbal remedies, commonly used in their living origin.

关键词： constipation Ea'teghal-e-batn herbal medicine traditional Persian medicine

Numerical analysis of rock fracturing by gas pressure using the extended finite element method

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Petroleum Science 2015年第2期12卷 304-315页

作者： majid Goodarzi Soheil Mohammadi Ahmad Jafari Department of Civil Engineering and Geoscience University of Newcastle School of Civil Engineering University of Tehran School of Mining Engineering University of Tehran

High energy gas fracturing is a simple approach of applying high pressure gas to stimulate wells by gen- erating several radial cracks without creating any other damages to the wells. In this paper, a numerical algorithm is proposed to quantitatively simulate propagation of these fractures around a pressurized hole as a quasi-static phenomenon. The gas flow through the cracks is assumed as a one-dimensional transient flow, governed by equations of conservation of mass and momentum. The fractured medium is modeled with the extended finite element method, and the stress intensity factor is calculated by the simple, though sufficiently accurate, displacement ex- trapolation method. To evaluate the proposed algorithm, two field tests are simulated and the unknown parameters are determined through calibration. Sensitivity analyses are performed on the main effective parameters. Considering that the level of uncertainty is very high in these types of engineering problems, the results show a good agreement with the experimental data. They are also consistent with the theory that the final crack length is mainly determined by the gas pressure rather than the initial crack length produced by the stress waves.

关键词： Gas fracturing Numerical modeling Extended finite element Fracture mechanics

iRNA-PseTNC:identification of RNA 5-methylcytosine sites using hybrid vector space of pseudo nucleotide composition

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Frontiers of Computer Science 2020年第2期14卷 451-460页

作者： Shahid AKBAR Maqsood HAYAT Muhammad iqbal Muhammad TAHIR Department of Computer Science Abdul Wali Khan University MardanKP 23200Pakistan

RNA 5-methylcytosine(m^5C)sites perform a major role in numerous biological processes and commonly reported in both DNA and RNA *** enzymatic mechanism and biological functions of m^5C sites in DNA remain the focusing area of researchers for last few ***,the investigators also targeted m^5C sites in RNA due to its cellular functions,positioning and formation ***,several rudimentary roles of the m^5C in RNA have been explored,but a lot of improvements are still under ***,the identification of RNA methylcytosine sites was carried out via experimental methods,which were very hard,erroneous and time consuming owing to partial availability of recognized *** at the significance of m^5C role in RNA,scientists have diverted their attention from structure to sequence-based *** this regards,an intelligent computational model is proposed in order to identify m^5C sites in RNA with high *** RNA sequences formulation methods namely:pseudo dinucleotide composition,pseudo trinucleotide composition and pseudo tetra nucleotide composition are applied to extract variant and high profound numerical *** a sequel,the vector spaces are fused to build a hybrid space in order to compensate the weakness of each *** learning hypotheses are examined to select the best operational engine,which can truly identify the pattern of the target *** strength and generalization of the proposed model are measured using two different cross validation *** reported outcomes reveal that the proposed model achieved 3%better accuracy than that of the highest present approach in the literature so far.

关键词： methylcytosine sites PseTNC PseTetraNC hybrid features SVM cross validation test

Long-term effects of main-body's obliquity on satellite formation perturbed by third-body gravity in elliptical and inclined orbit

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Research in Astronomy and Astrophysics 2017年第4期17卷 81-96页

作者： majid Bakhtiari Kamran Daneshjou Mahdi Fakoor Department of Mechanical Engineering Iran University of Science and Technology Department of Aerospace Engineering Faculty of New Sciences and TechnologiesUniversity of Tehran

A new non-simplified model of formation flying is derived in the presence of an oblate main- body and third-body perturbation. In the proposed model, considering the perturbation of the third- body in an inclined orbit, the effect of obliquity （axial tilt） of the main-body is becoming important and has been propounded in the absolute motion of a reference satellite and the relative motion of a follower satellite. From a new point of view, J2 perturbed relative motion equations and considering a disturbing body in an elliptic inclined three dimensional orbit, are derived using Lagrangian mechanics based on accurate introduced perturbed reference satellite motion. To validate the accuracy of the model presented in this study, an auxiliary model was constructed as the Main-body Center based Relative Motion （MCRM） model. Finally, the importance of the main-body＇s obliquity is demonstrated by several examples related to the Earth-Moon system in relative motion and lunar satellite formation keeping. The main-body＇s obliquity has a remarkable effect on formation keeping in the examined in-track and projected circular orbit （PCO） formations.

关键词： space vehicles - celestial mechanics - Moon - planets and satellites - formation -obliquity

Square wave voltammetric quantification of folic acid,uric acid and ascorbic acid in biological matrix

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Journal of Pharmaceutical Analysis 2017年第2期7卷 110-117页

作者： majid Arvand Akram Pourhabib Masoud Giahi Electroanalytical Chemistry Laboratory Faculty of ScienceUniversity of GuilanNamjooStreetP.O.Box:1914RashtIran Education Organization of Guilan Province Farhang SquareP.O.Box:41849-83111RashtIran Department of Chemistry Faculty of ScienceLahijan BranchIslamic Azad UniversityP.O.Box:1616LahijanIran

Nowadays, modified electrodes with metal nanoparticles have appeared as an alternative for the electroanalysis of various compounds. In this study, gold nanoparticles（GNPs） were chosen as interesting metal nanoparticles for modifying carbon paste electrode（CPE）. GNPs and the gold nanoparticles-modified carbon paste electrode（GNPs/CPE） were characterized by UV–Vis spectroscopy, transmission electron microscopy（TEM） and scanning electron microscopy（SEM）. GNPs/CPE as a simple and sensitive electrode was used to study three important biological molecules： folic acid（FA）, uric acid（UA） and ascorbic acid（AA）. Square wave voltammetry（SWV） was used as an accurate technique for quantitative measurements. A good linear relation was observed between anodic peak current（ipa） and FA（5.2 × 10（-6）– 2.5 × 10（-5）M）, UA（1.2 × 10（-6）– 2.1 × 10（-5）M） and AA（1.2 × 10（-6）– 2.5 × 10（-5）M） concentrations in simultaneous determination of these molecules.

关键词： Ascorbic acid Folic acid gold nanoparticles-modified carbon paste electrode Simultaneous determination Uric acid

Small Signal Stability of Three-phase and Six-phase Synchronous Motors:A Comparative Analysis

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Chinese Journal of Electrical Engineering 2020年第1期6卷 22-40页

作者： G.K.Singh Arif iqbal Department of Electrical Engineering Indian Institute of TechnologyRoorkee 247667India Department of Electrical Engineering Rajkiya Engineering College Ambedkar NagarAkbarpur 224122India

Small signal stability analysis is conducted for an asymmetrical six-phase synchronous motor in comparison with its equivalent three-phase *** this purpose,a linearized model of the six-phase synchronous motor is developed using the dq0 approach,which is used in eigenvalue criteria to determine absolute stability in comparison with its equivalent three-phase *** analysis includes a comparison of the variation in evaluated eigenvalues associated with the stator and rotor sides according to changes in both the three and six-phase machine parameters and working *** analytical results are experimentally investigated and validated on a test rig.

关键词： Linearized modeling stability analysis six-phase synchronous motor three-phase synchronous motor