Search results for "density"

Models and methods for space and space-time interactions in complex point processes with applications on earthquakes

Matching across space: evidence from Finland

2005

This paper studies spatial aspects in local labour markets in Finland from the perspective of a matching approach. The monthly data comprise 173 Local Labour Office are as over a 12-year period between January 1991 and August 2002. The basic matching function is extended to account for spatial spill-overs between the local labour markets. The role of population density in the matching process is also examined. According to results, the Finnish local labour markets suffer from a strong congestion effect among job seekers, and spatial spill-overs even strengthen the congestion. An open vacancy is filled much easier than a job seeker is employed. The results show that the matching efficiency i…

Gallium preference for the occupation of tetrahedral sites in Lu3(Al5-xGax)O12multicomponent garnet scintillators according to solid-state nuclear ma…

2019

Abstract In this study, the distributions of aluminum and gallium atoms over the tetrahedral and octahedral sites in the garnet structure were investigated in mixed Lu3Al5-xGaxO12 crystals by using 27Al and 71Ga magic angle spinning nuclear magnetic resonance (NMR) and single crystal 71Ga NMR. The experimental study was supported by theoretical calculations based on density functional theory (DFT) in order to predict the trends in terms of the substitutions of Al by Ga in the mixed garnets. Both the experimental and theoretical results indicated the non-uniform distribution of Al and Ga over the tetrahedral and octahedral sites in the garnet structure, with a strong preference for Ga occupy…

A Theoretical and Experimental Investigation of the Spectroscopic Properties of a DNA-Intercalator Salphen-Type ZnIIComplex

2014

The photophysical and DNA-binding properties of the cationic zinc(II) complex of 5-triethylammonium methyl salicylidene ortho-phenylenediiminato (ZnL 2 + ) were investi- gated by a combination of experimental and theoretical methods. DFT calculations were performed on both the ground and the first excited states of ZnL 2 + and on its possi- ble mono- and dioxidation products, both in vacuo and in selected solvents mimicked by the polarizable continuum model. Comparison of the calculated absorption and fluores- cence transitions with the corresponding experimental data led to the conclusion that visible light induces a two-elec- tron photooxidation process located on the phenylenediimi- nato…

Octopus, a computational framework for exploring light-driven phenomena and quantum dynamics in extended and finite systems

2020

Over the last few years, extraordinary advances in experimental and theoretical tools have allowed us to monitor and control matter at short time and atomic scales with a high degree of precision. An appealing and challenging route toward engineering materials with tailored properties is to find ways to design or selectively manipulate materials, especially at the quantum level. To this end, having a state-of-the-art ab initio computer simulation tool that enables a reliable and accurate simulation of light-induced changes in the physical and chemical properties of complex systems is of utmost importance. The first principles real-space-based Octopus project was born with that idea in mind,…

A microsimulation calibration methodology based on speed-density relationships for freeways

2014

This paper describes the calibration methodology based on speed-density relationships in the microsimulation calibration process, stated that they represent the traffic flow phenomenon in a wide range of operational conditions and well summarize all the information that may be collected on field (or following a run of the microsimulation model) on two of the three key variables of traffic flow. The matching of speed-density relationships from field and simulation was evaluated using statistical analysis as technique of pattern recognition. A test freeway segment under uncongested traffic conditions was selected as case study; based on traffic data observed at A22 Brenner Freeway, Italy, sta…

Supercurrent-induced charge-spin conversion in spin-split superconductors

2018

We study spin-polarized quasiparticle transport in a mesoscopic superconductor with a spin-splitting field in the presence of coflowing supercurrent. In such a system, the nonequilibrium state is characterized by charge, spin, energy, and spin-energy modes. Here we show that in the presence of both spin splitting and supercurrent, all these modes are mutually coupled. As a result, the supercurrent can convert charge imbalance, which in the presence of spin splitting decays on a relatively short scale, to a long-range spin accumulation decaying only via inelastic scattering. This effect enables coherent charge-spin conversion controllable by a magnetic flux, and it can be detected by studyin…

Molecular and supramolecular structures of self-assembled Cu(II) and Co(II) complexes with 4,4’-[6-(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazine-2,4-…

2020

The molecular and supramolecular structures of [Cu(PTM)Cl2]*0.75MeOH (1), [Co(PTM)Cl2]; (2A) and [Co(PTM)Cl2(EtOH)]; (2B) complexes, where PTM is 4,4’-[6-(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazine-2,4-diyl]dimorpholine, were presented. In complexes 1 and 2A, the Cu(II) and Co(II) are tetra-coordinated with a distorted tetrahedral coordination environment. In case of complex 2B, an additional ethanol molecule is found coordinated with Co(II) leading to a highly distorted penta-coordinated Co(II) complex. In all cases, the PTM ligand is acting as a bidentate NN-chelate. Hirshfeld surface analysis indicated the importance of H⋯H (49.0–55.1%), Cl⋯H (18.8–20.5%) and O⋯H (8.3–9.9%) contacts in…

Spin caloric transport from density-functional theory

2019

Spin caloric transport refers to the coupling of heat with spin transport. Its applications primarily concern the generation of spin currents and control of magnetisation by temperature gradients for information technology, known by the synonym spin caloritronics. Within the framework of ab initio theory, new tools are being developed to provide an additional understanding of these phenomena in realistic materials, accounting for the complexity of the electronic structure without adjustable parameters. Here, we review this progress, summarising the principles of the density-functional-based approaches in the field and presenting a number of application highlights. Our discussion includes th…

Aliasing-Free and Additive Error in Mixed Spectra for Stable Processes. Application: Sound of a Bird just captivated in stress

2022

Consider a symmetric continuous time α stableprocess observed with an additive constant error. Theobjective of this paper is to give a non-parametric estimatorof this error by using discrete observations. As the time ofprocess is continuous and the observations are discrete, weencountered the aliasing phenomenon. Our process sampleis taken in a way to circumvent the difficulty related toaliasing and we smoothed the periodogram by using JacksonKernel. The rate of convergence of this estimator is studiedwhen the spectral density is zero at origin. Few long memoryprocesses are taken here as examples. We have applied ourestimator to the concrete case of modeling noise of a birdcaptured under st…