Search results for "Valence"

C2C interactions creating value in the Route of Santiago

2016

The role of interaction between customers (customer-to-customer; C2C) is a key factor when extracting value from a touristic experience. Several studies incorporate quantitative and qualitative aspects referring to interactions and can provide a holistic view about C2C experiences, being therefore more capable of predicting the effects of C2C interaction on customer behavior. This study analyzes C2C interactions in backpackers’ experience and their effect on the cruise experience and vacation satisfaction. The study uses fuzzy-set qualitative comparative analysis (fsQCA) to explore a causal relationship with dichotomous outcomes, both the presence and the absence of the variables. The study…

Ekspertu novērtējumu agregācija, balstoties uz ekvivalences attiecību

2016

Darbs ir veltīts vispārinātā agregācijas operatora speciālai konstrukcijai, kas balstīts uz nestriktu ekvivalences attiecību. Darba mērķis ir aprakstīt kā var agregēt ekspertu novērtējumus gadījumā, kad starp novērtētiem objektiem pastāv līdzība, kas uzdota ar nestriktu ekvivalences attiecību. Piedāvātā metode ir ilustrētā ar ekonomiska rakstura piemēru.

Cubic aromaticity in ligand-stabilized doped Au superatoms

2021

The magnetic response of valence electrons in doped gold-based [M@Au8L8]q superatoms (M = Pd, Pt, Ag, Au, Cd, Hg, Ir, and Rh; L = PPh3; and q = 0, +1, +2) is studied by calculating the gauge including magnetically induced currents (GIMIC) in the framework of the auxiliary density functional theory. The studied systems include 24 different combinations of the dopant, total cluster charge, and cluster structure (cubic-like or oblate). The magnetically induced currents (both diatropic and paratropic) are shown to be sensitive to the atomic structure of clusters, the number of superatomic electrons, and the chemical nature of the dopant metal. Among the cubic-like structures, the strongest arom…

Air gasification of wood chips, wood pellets and grass pellets in a bubbling fluidized bed reactor

2021

Abstract Gasification is an attractive method for biomass-to-energy conversion and fluidized bed design is one of the best options for large scale operation. A bubbling fluidized bed reactor was used to analyze the effects of biomass type, equivalence ratio (ER) and temperature for product gas compositions. Wood chips, wood pellets and grass pellets were gasified between 650 °C and 800 °C temperature. The ER was varied between 0.08 and 0.16. Gasification of grass pellets was difficult at 800 °C due to agglomeration and the gas composition was poor compared to wood. The reactor performances improved over the temperature and 650 °C was not sufficient to achieve a reasonable carbon conversion.…

Covalent bonding and the nature of band gaps in some half-Heusler compounds

2005

Half-Heusler compounds \textit{XYZ}, also called semi-Heusler compounds, crystallize in the MgAgAs structure, in the space group $F\bar43m$. We report a systematic examination of band gaps and the nature (covalent or ionic) of bonding in semiconducting 8- and 18- electron half-Heusler compounds through first-principles density functional calculations. We find the most appropriate description of these compounds from the viewpoint of electronic structures is one of a \textit{YZ} zinc blende lattice stuffed by the \textit{X} ion. Simple valence rules are obeyed for bonding in the 8-electron compound. For example, LiMgN can be written Li$^+$ + (MgN)$^-$, and (MgN)$^-$, which is isoelectronic wi…

Random Structural Modification of a Low-Band-Gap BODIPY-Based Polymer

2017

International audience; A BODIPY thiophene polymer modified by extending conjugation of the BODIPY chromophore is reported. This modification induces tunability of energy levels and therefore absorption wavelengths in order to target lower energies.

Magnetic Heusler Compounds

2013

Abstract Heusler compounds are a remarkable class of intermetallic materials with 1:1:1 (often called Half-Heusler) or 2:1:1 composition comprising more than 1500 members. New properties and potential fields of applications emerge constantly; the prediction of topological insulators is the most recent example. Surprisingly, the properties of many Heusler compounds can easily be predicted by the valence electron count or within a rigid band approach. The wide range of the multifunctional properties of Heusler compounds is reflected in extraordinary magnetooptical, magnetoelectronic, and magnetocaloric properties. Co 2 -Heusler compounds are predicted and proven half-metallic ferromagnets sho…

Nanosession: Valence Change Memories - A Look Inside

2013

Photoactivity under visible light of metal loaded TiO2 catalysts prepared by low frequency ultrasound treatment

2017

Abstract Visible-light responsive bare and metal loaded (Pt, Ag, Rh, Pd) TiO 2 photocatalysts were prepared by using a simple ultrasound treatment. This method induced bulk oxygen deficiency resulting in a narrowing bandgap (from 3.18 to 3.04 eV) and in visible light absorption. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), BET specific surface area (SSA) and pore size distribution (PSD), UV–vis diffuse reflectance spectroscopy (DRS), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of the samples was evaluated by using the 4-nitrophenol oxidation reaction and the photocatalytic oxidation of glucose w…

Polymorphism in phase-change materials: melt-quenched and as-deposited amorphous structures in Ge2Sb2Te5from density functional calculations

2011

The as-deposited (AD) amorphous structure of the prototype phase change material Ge${}_{2}$Sb${}_{2}$Te${}_{5}$ (GST-225) has been studied by density functional calculations for a 648-atom sample generated by computer-aided deposition at 300 K. The AD sample differs from a melt-quenched (MQ) sample in essential ways: (1) Ge atoms are predominantly tetrahedrally coordinated, and (2) homopolar and Ge-Sb bonds are more common and reduce the number of $\mathit{ABAB}$ squares ($A=\mathrm{Ge}$, Sb; $B=\mathrm{Te}$), the characteristic building blocks of the material. The first observation resolves the contradiction between measured (EXAFS) and calculated Ge-Te bond lengths, and the latter explain…