Search results for "Calculation"

showing 10 items of 594 documents

Molecular dynamics of CH4/N2 mixtures on a flexible graphene layer: adsorption and selectivity case study

2019

We theoretically investigate graphene layers, proposing them as membranes of subnanometer size suitable for CH4/N2 separation and gas uptake. The observed potential energy surfaces, representing the intermolecular interactions within the CH4/N2 gaseous mixtures and between these and the graphene layers, have been formulated by adopting the so-called Improved Lennard-Jones (ILJ) potential, which is far more accurate than the traditional Lennard-Jones potential. Previously derived ILJ force fields are used to perform extensive molecular dynamics simulations on graphene's ability to separate and adsorb the CH4/N2 mixture. Furthermore, the intramolecular interactions within graphene were explic…

Materials scienceUNESCO::QUÍMICA02 engineering and technology010402 general chemistry01 natural sciences:QUÍMICA [UNESCO]law.inventionlcsh:ChemistryMolecular dynamicsAdsorptionlawAb initio quantum chemistry methodsFlexibility (engineering)Grapheneab initio calculationsIntermolecular forceGeneral Chemistryflexible graphene021001 nanoscience & nanotechnologyPotential energymolecular dynamics0104 chemical scienceslcsh:QD1-999adsorptionChemical physicsIntramolecular forceab-initio potential0210 nano-technologyAb initio calculations; Ab-initio potential; Adsorption; Flexible graphene; Molecular dynamics
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Ambipolar MoS2 Transistors by Nanoscale Tailoring of Schottky Barrier Using Oxygen Plasma Functionalization

2017

One of the main challenges to exploit molybdenum disulfide (MoS2) potentialities for the next-generation complementary metal oxide semiconductor (CMOS) technology is the realization of p-type or ambipolar field-effect transistors (FETs). Hole transport in MoS2 FETs is typically hampered by the high Schottky barrier height (SBH) for holes at source/drain contacts, due to the Fermi level pinning close to the conduction band. In this work, we show that the SBH of multilayer MoS2 surface can be tailored at nanoscale using soft O-2 plasma treatments. The morphological, chemical, and electrical modifications of MoS2 surface under different plasma conditions were investigated by several microscopi…

Materials scienceambipolar transistorsSchottky barrierDFT calculationNanotechnology02 engineering and technologyDFT calculations01 natural scienceschemistry.chemical_compoundX-ray photoelectron spectroscopy0103 physical sciencesScanning transmission electron microscopyGeneral Materials ScienceSchottky barrierMolybdenum disulfide010302 applied physicsAmbipolar diffusionElectron energy loss spectroscopyConductive atomic force microscopy021001 nanoscience & nanotechnologyconductive atomic force microscopyatomic resolution STEMchemistryambipolar transistorSurface modificationMaterials Science (all)0210 nano-technologyMoS2
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Understanding and Predicting Plutonium Alloys Aging: A Coupled Experimental and Theoretical Approach

2003

Understanding plutonium aging is a real challenge that requires developing very ambitious modeling and experiments. Examples of the different techniques developed and the physical values that can be reached are presented here.

Materials sciencechemistryRadiochemistrychemistry.chemical_elementBiochemical engineeringCalculation methodsPlutoniumAIP Conference Proceedings
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Density functional theory description of random Cu-Au alloys

2019

Density functional alloy theory is used to accurately describe the three core effects controlling the thermodynamics of random Cu-Au alloys. These three core effects are exchange correlation (XC), ...

Materials scienceta114tiheysfunktionaaliteoriaAlloyThermodynamics02 engineering and technologyengineering.materialelectronic structure021001 nanoscience & nanotechnology01 natural sciencesCore (optical fiber)Condensed Matter::Materials Sciencealloysfirst-principles calculations0103 physical sciencesengineeringDensity functional theorymetalliseokset010306 general physics0210 nano-technologyta116density functional theoryPhysical Review B
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A General Methodology for Short-circuit Calculations in Hybrid AC/DC Microgrids

2023

In this paper, the issues related to short-circuit calculations in hybrid AC/DC microgrids are discussed. The reference standard for short-current calculations in DC systems is the IEC 61660, which provides a mathematical formulation of the problem. The standard only includes radial DC grids and does not consider a more complex system, such as meshed DC systems or a hybrid AC/DC microgrid. This paper proposes a generalized approach that can be used independently of the characteristics of the hybrid system. The proposed approach is applied to four test microgrids with different distributed sources and number of nodes and the results are compared with those obtained simulating the same grids …

Mathematical modelsStandardsResistanceShort-circuit currentsVoltageIEC StandardsShort-circuithybrid systemsIndustrial and Manufacturing EngineeringSettore ING-IND/33 - Sistemi Elettrici Per L'EnergiaAC/DC MicrogridsControl and Systems EngineeringMicrogridsElectrical and Electronic EngineeringFault calculationIEEE Transactions on Industry Applications
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Calculation of cost-optimal combination of building materials and technical systems for nZEB single-family house using global cost calculation method

2019

As a rule, during the design stage of a single-family house, only initial costs are taken into account and optimised. Long-term financial calculations are usually not even made. At the same time, total costs to design, build and operate the building show a real difference in expenses while living in this house. In the case of nearly zero energy buildings (nZEBs), this global cost approach becomes especially useful because of the strict requirements of heating and primary energy, as well as the compulsory use of renewable energy sources, requiring more detailed and comprehensive calculations of a cost-optimal set of solutions. In this study, a nZEB single-family house is analysed in detail u…

Mathematical optimizationlcsh:TA1-2040Computer scienceSingle-family detached homeTechnical systemsOptimal combinationlcsh:Engineering (General). Civil engineering (General)Cost calculationMATEC Web of Conferences
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Construction of a fundamental set of solutions of an arbitrary homogeneous linear difference equation

2002

Abstract The detailed construction of a prefixed fundamental set of solutions of a linear homogeneous difference equation of any order with arbitrarily variable coefficients is reported. The usefulness of the resulting resolutive formula is illustrated by simple applications to the Hermite polynomials and to the Fibonacci sequence.

Matrix difference equationFibonacci numberHermite polynomialsDifferential equationMathematical analysisMathematicsofComputing_NUMERICALANALYSISCharacteristic equationStatistical and Nonlinear PhysicsDifference equation matrix calculations Fibonacci sequence.Homogeneous differential equationComputingMethodologies_SYMBOLICANDALGEBRAICMANIPULATIONLinear difference equationMathematical PhysicsVariable (mathematics)MathematicsReports on Mathematical Physics
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Adducts of free-base meso-tetraarylporphyrins with trihaloacetic acids: Structure and photostability

2020

Abstract Four diverse meso-tetraarylporphyrins in the form of diprotonated adducts with trifluoro-, trichloro-, tribromoacetic acids and acetic acid were investigated in benzene solution. Despite similar structural distortion of the chromophore system due to protonation, the respective adducts demonstrated different photostability when exposed to UV irradiation. The trifluoro- and trichloroacetic adducts, and the acetic acid one, showed some common features both molecular and in the mechanism of photodegradation. However, the tribromo-derivative decayed according to a different kinetic scheme, revealing a considerable impact of the bromine atoms upon the pyrrole units of the porphyrin macro…

Meso-tetraarylporphyrinsSinglet oxygenGeneral Chemical EngineeringGeneral Physics and AstronomyFree baseProtonation02 engineering and technologyGeneral ChemistryChromophore010402 general chemistry021001 nanoscience & nanotechnologyPhotochemistryDFT calculations01 natural sciencesPorphyrinTrihaloacetic acids0104 chemical sciencesAdductPorphyrin protonationchemistry.chemical_compoundAcetic acidchemistry0210 nano-technologyPhotodegradationPyrroleJournal of Photochemistry and Photobiology A-Chemistry
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Group 10 Metal Benzene-1,2-dithiolate Derivatives in the Synthesis of Coordination Polymers Containing Potassium Countercations

2017

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Inorganic Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/abs/10.1021/acs.inorgchem.7b01775

Metal saltsCoordination polymerPotassiumInorganic chemistrychemistry.chemical_element010402 general chemistry01 natural sciencesInorganic ChemistryMetalchemistry.chemical_compoundFirst-principles calculationsGroup (periodic table)Physical and Theoretical ChemistryBenzenechemistry.chemical_classification010405 organic chemistryChemistryPolymerQuímica0104 chemical sciencesCoordination polymersCrystallographyMetal-dithiolene polymersvisual_artvisual_art.visual_art_mediumCoordination compoundsPlatinum
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Reaction between Indazole and Pd-Bound Isocyanides-A Theoretical Mechanistic Study

2018

The mechanism of the addition of indazole (Ind)&mdash

Models Molecular3003Activation of small moleculesIndazolesisocyanideIsocyanidePharmaceutical ScienceDFT calculationProtonation010402 general chemistryDFT calculationsactivation of small molecule01 natural sciencesMedicinal chemistryArticleAnalytical Chemistrylcsh:QD241-441chemistry.chemical_compoundDeprotonationNucleophilelcsh:Organic chemistryTheoreticalModelsDrug DiscoveryNitrilesPhysical and Theoretical ChemistryMechanical PhenomenaIndazoleNucleophilic additionCyanidesMolecular Structure010405 organic chemistrynitrileDrug Discovery3003 Pharmaceutical ScienceOrganic ChemistryRegioselectivityMolecularIsocyanidesModels TheoreticalTautomer0104 chemical sciencesnucleophilic additionchemistryChemistry (miscellaneous)Settore CHIM/03 - Chimica Generale E InorganicaMolecular Medicinereaction mechanismActivation of small molecules; DFT calculations; Isocyanides; Nitriles; Nucleophilic addition; Reaction mechanism; Cyanides; Indazoles; Models Molecular; Molecular Structure; Palladium; Mechanical Phenomena; Models Theoretical; Analytical Chemistry; Chemistry (miscellaneous); Molecular Medicine; 3003; Drug Discovery3003 Pharmaceutical Science; Physical and Theoretical Chemistry; Organic ChemistryPalladium
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