Search results for "funktio"

Atomistic Insights into Nitrogen-Cycle Electrochemistry: A Combined DFT and Kinetic Monte Carlo Analysis of NO Electrochemical Reduction on Pt(100)

2017

Electrocatalytic denitrification is a promising technology for the removal of NOx species in groundwater. However, a lack of understanding of the molecular pathways that control the overpotential and product distribution have limited the development of practical electrocatalysts, and additional atomic-level insights are needed to advance this field. Adsorbed NO has been identified as a key intermediate in the NOx electroreduction network, and the elementary steps by which it decomposes to NH4+, N2, NH3OH+, or N2O remain a subject of debate. Herein, we report a combined density functional theory (DFT) and kinetic Monte Carlo (kMC) study of this reaction on Pt(100), a catalytic surface that i…

Unique continuation results for certain generalized ray transforms of symmetric tensor fields

2022

Let $I_{m}$ denote the Euclidean ray transform acting on compactly supported symmetric $m$-tensor field distributions $f$, and $I_{m}^{*}$ be its formal $L^2$ adjoint. We study a unique continuation result for the normal operator $N_{m}=I_{m}^{*}I_{m}$. More precisely, we show that if $N_{m}$ vanishes to infinite order at a point $x_0$ and if the Saint-Venant operator $W$ acting on $f$ vanishes on an open set containing $x_0$, then $f$ is a potential tensor field. This generalizes two recent works of Ilmavirta and M\"onkk\"onen who proved such unique continuation results for the ray transform of functions and vector fields/1-forms. One of the main contributions of this work is identifying t…

Nuclear Charge Radii of the Nickel Isotopes $^{58-68,70}$Ni

2022

Collinear laser spectroscopy is performed on the nickel isotopes Ni58-68,70, using a time-resolved photon counting system. From the measured isotope shifts, nuclear charge radii Rc are extracted and compared to theoretical results. Three ab initio approaches all employ, among others, the chiral interaction NNLOsat, which allows an assessment of their accuracy. We find agreement with experiment in differential radii δ⟨rc2⟩ for all employed ab initio methods and interactions, while the absolute radii are consistent with data only for NNLOsat. Within nuclear density functional theory, the Skyrme functional SV-min matches experiment more closely than the Fayans functional Fy(Δr,HFB). Collinear …

Nuclear moments of indium isotopes reveal abrupt change at magic number 82

2022

In spite of the high-density and strongly correlated nature of the atomic nucleus, experimental and theoretical evidence suggests that around particular 'magic' numbers of nucleons, nuclear properties are governed by a single unpaired nucleon1,2. A microscopic understanding of the extent of this behaviour and its evolution in neutron-rich nuclei remains an open question in nuclear physics3-5. The indium isotopes are considered a textbook example of this phenomenon6, in which the constancy of their electromagnetic properties indicated that a single unpaired proton hole can provide the identity of a complex many-nucleon system6,7. Here we present precision laser spectroscopy measurements perf…

The Syntheses and Vibrational Spectra of 16O- and 18O-Enriched cis-MO2 (M=Mo, W) Complexes

2018

In this contribution, we report convenient synthetic approaches for obtaining 16O/18O‐enriched dioxidometalVI complexes, MO2(L) (W, Mo), with a linear, tetradentate amine phenolate ligand N,N′‐dimethyl‐N,N′‐bis(2‐hydroxy‐3,5‐dimethylbenzyl)ethylenediamine (H2L) and describe their characterization by IR and Raman spectroscopy complemented by DFT computational analysis. The isotopologues of WO2(L) were made of tungstenVI trisglycolate W(eg)3 (eg=1,2‐ethanediolate dianion) and ligand H2L in the presence of either H2[16O] or H2[18O], whereas Mo16O2(L) was made using Na2MoO4⋅2H2O which was converted to Mo18O2(L) by oxido substitution using H2[18O]. The complementary IR and Raman analyses show th…

The Syntheses and Vibrational Spectra of 16 O- and 18 O-Enriched cis -MO2 (M=Mo, W) Complexes

2018

Many-particle theory for time-dependent quantum transport in nanostructures

2012

During the recent decades, molecular electronics has established its place as one of the promising fields in the nanoscience. The possibility to manufacture and control molecular junctions where single molecules are squeezed between the conducing electrodes has opened up new possibilities to develop nanoscale devices which could be employed as building blocks for future nanoelectronic applications. The driving force for this new branch of physics has been the experimental advances but also theoretical methods have been under intensive study and many theoretical tools have been developed to understand the electron transport processes in the nanoscale systems. This thesis focuses on developin…

Johtajien näkemyksiä sosiaalisesta mediasta työyhteisöviestinnässä

2016

Tämän puheviestinnän maisterintutkielman tavoitteena oli selvittää johtajien kokemuksia ja käsityksiä sosiaalisesta mediasta työyhteisöviestinnässä. Tutkimuksessa selvitettiin työyhteisöviestinnän tavoitteita ja funktioita, haasteita sekä johtajan roolia sosiaalisessa mediassa. Tässä tutkielmassa työyhteisöviestintä nähtiin muun muassa työhön ja työpaikan suhteisiin liittyvänä vuorovaikutuksena sosiaalisen median sovelluksissa, joihin kaikilla työyhteisön jäsenillä oli pääsy. Sosiaalinen media käsitettiin erilaisina kehittyneelle teknologialle perustuvina sovelluksina, jotka mahdollistavat monipuolisen vuorovaikutuksen ja sisällöntuotannon. Näitä sovelluksia ovat esimerkiksi Facebook, Skype…

Iterated function systems: natural measure and local structure

2003

DFT Prediction of Enhanced Reducibility of Monoclinic Zirconia upon Rhodium Deposition

2018

Oxides are an important class of materials and are widely used, for example, as supports in heterogeneous catalysis. In a number of industrial catalytic processes, oxide supports actively participate in chemical transformations by releasing lattice oxygen anions. While this is intuitively understood for reducible oxides, the reducibility of irreducible oxides may be modified via nanoengineering or upon inclusion of foreign species. Our calculations predict that the ability of irreducible monoclinic zirconia to release oxygen improves substantially upon deposition of rhodium. Through a comprehensive screening of Rh/ZrO2 with different size of the rhodium species, we find that a Rh adatom and…