Search results for "14"
showing 10 items of 9841 documents
Single Crystal Sub‐Nanometer Sized Cu6(SR)6 Clusters: Structure, Photophysical Properties, and Electrochemical Sensing
2016
Organic ligand-protected metal nanoclusters have attracted extensively attention owing to their atomically precise composition, determined atom-packing structure and the fascinating properties and promising applications. To date, most research has been focused on thiol-stabilized gold and silver nanoclusters and their single crystal structures. Here the single crystal copper nanocluster species (Cu6(SC7H4NO)6) determined by X-ray crystallography and mass spectrometry is presented. The hexanuclear copper core is a distorted octahedron surrounded by six mercaptobenzoxazole ligands as protecting units through a simple bridging bonding motif. Density functional theory (DFT) calculations provide…
Silver Sulfide Nanoclusters and the Superatom Model
2015
The superatom model of electron-shell closings has been widely used to explain the stability of noble-metal nanoclusters of few nanometers, including thiolate-protected Au and Ag nanoclusters. The presence of core sulfur atoms in silver sulfide (Ag–S) nanoclusters renders them a class of clusters with distinctive properties as compared to typical noble-metal clusters. Here, it is natural to ask whether the superatom model is still applicable for the Ag–S nanoclusters with mixed metal and nonmetal core atoms. To address this question, we applied density functional simulations to analyze a series of Ag–S nanoclusters: Ag14S(SPh)12(PPh3)8, Ag14(SC6H3F2)12(PPh3)8, Ag70S16(SPh)34(PhCO2)4(triphos…
Atomic layer deposition of AlN from AlCl3 using NH3 and Ar/NH3 plasma
2018
The atomic layer deposition (ALD) of AlN from AlCl3 was investigated using a thermal process with NH3 and a plasma-enhanced (PE)ALD process with Ar/NH3 plasma. The growth was limited in the thermal process by the low reactivity of NH3, and impractically long pulses were required to reach saturation. Despite the plasma activation, the growth per cycle in the PEALD process was lower than that in the thermal process (0.4A ° vs 0.7A ° ). However, the plasma process resulted in a lower concentration of impurities in the films compared to the thermal process. Both the thermal and plasma processes yielded crystalline films; however, the degree of crystallinity was higher in the plasma process. The…
Stability, electronic structure, and optical properties of protected gold-doped silver Ag29−xAux (x = 0–5) nanoclusters
2017
In this work, we used density functional theory (DFT) and linear response time-dependent DFT (LR-TDDFT) to investigate the stability, electronic structure, and optical properties of Au-doped [Ag29-xAux(BDT)12(TPP)4]3- nanoclusters (BDT: 1,3-benzenedithiol; TPP triphenylphosphine) with x = 0-5. The aim of this work is to shed light on the most favorable doped structures by comparing our results with previously published experimental data. The calculated relative energies, ranging between 0.8 and 10 meV per atom, indicate that several doped Ag29-xAux nanoclusters are likely to co-exist at room temperature. However, only the Au-doped [Ag29-xAux(BDT)12(TPP)4]3- nanoclusters that have direct bon…
The Recovery of the Optimal Damping Constant by the MRF Damper
2009
In this paper was studied a method to analyze the recovering of optimal damping constant because of temperature increasing in a shock absorber. The increasing on temperature leads to decreasing that constant by mean dynamic viscosity such to modify the dynamic behavior of a 2DOF system built-up by sprung and unsprung mass. A MagnetoRheological damper was designed according with the desired optimal damping constant once fixed temperature design. It was seen that the increasing of temperature this constant is lost. As MagnetoRheological-Fluids allows us to increase the viscosity, we use a control signal by a state feedback of reduced order to create a such magnetic induction field to recover …
Archicottura: architettura e pratiche sociali
2020
In una realtà interattiva e reattiva non stupisce il crescente interesse per la relazione tra architettura e pratiche sociali (Archi_Cottura). Delle molteplici declinazioni in cui il rapporto può essere inteso è utile soffermarsi, fra ‘cose’ e ‘dispositivi’, sui luoghi e gli spazi che individuano delle diverse potenzialità identitarie. Architettura e pratiche sociali intrattengono un legame più profondo se li consideriamo come forme di interpretazione del rapporto fra la memoria ancestrale dell’uomo e il dinamismo spaziale che si coagula in idee e azioni di progetto. Trovandoci nell’era della domotica questa tensione ermeneutica del costruire viene controbilanciata, all’interno dell’organis…
Tra architettura e agricoltura
2014
A phase of PRIN 2009 reasearch went off through some seminars. Prof. A. Sciascia (Unit Leader) has involved professors of some departments, converging different experiences to expand starting scientific knowledge as much as possible. This activity has offered the possibility to listen to Tiziano Caruso, Tommaso La Mantia and Giuseppe Lo Papa, professors of Faculty of Agriculture, experienced in arboreal cultivations (the first and the second) and agriculture geology (the third). Their reports, whose we analyse here the synthesis of the conversation with Tiziano Caruso, allow to put together complementary points of view about the definitive agricultural cultivations and the economy of the co…
Un workshop di progettazione a Palermo
2015
L'articolo presenta un lavoro di progettazione, un workshop, sull'ospedale psichiatrico di Palermo, svolto all'interno della ricerca PRIN sugli ospedali italiani tra Ottocento e Novecento. Il gruppo da me coordinato era l'unico con maggioranza di docenti di Composizione, quindi si è data una indicazione sul possibile futuro di questi complessi, di cui quello di Palazzotto a Palermo è certo uno dei più completi e significativi.
Merging Features from Green's Functions and Time Dependent Density Functional Theory: A Route to the Description of Correlated Materials out of Equil…
2016
We propose a description of nonequilibrium systems via a simple protocol that combines exchange-correlation potentials from density functional theory with self-energies of many-body perturbation theory. The approach, aimed to avoid double counting of interactions, is tested against exact results in Hubbard-type systems, with respect to interaction strength, perturbation speed and inhomogeneity, and system dimensionality and size. In many regimes, we find significant improvement over adiabatic time dependent density functional theory or second Born nonequilibrium Green's function approximations. We briefly discuss the reasons for the residual discrepancies, and directions for future work.
Assessing violence in the family : social work, courts, and discourses
2016
This article investigates social work, decision-making, and gendered violence in the family in Finland. Discourses on gendered violence in the family are compared in custody disputes, handled in district courts, and out-of-home placements, dealt with in administrative courts. Both data sets altogether include 237 cases. Proceedings in both courts share a legislative emphasis on the ‘child’s best interest’ principle, and both contexts also rely on documentation provided by social workers. The examination of the two studies is based on discourse analysis, through which we have identified hegemonic discourses that are active in both courts. The study found that violence was often disregarded o…