Search results for " Density"

showing 10 items of 2709 documents

Supercooled Water Confined in a Silica Xerogel: Temperature and Pressure Dependence of Boson Peak and of Mean Square Displacements

2013

A silica xerogel can be obtained from an alcoxide precursor (TMOS, tetramethylortosilcate) via the sol-gel method: TMOS hydrolysis and subsequent polycondensation yields a solid, disordered, porous SiO2 matrix (average pore dimensions ~20Å). Inside the pores water is trapped and the hydration level h=gr[H2O]/gr[SiO2] can be easily controlled. The presence and temperature dependence of the boson peak (BP) in xerogel confined supercooled water was studied with inelastic neutron scattering (spectrometer IN6 at ILL, Grenoble) in xerogel samples having h=0.4 and h=0.2. After careful subtraction of the contributions arising from the matrix and from quasi-elastic scattering, the BP contribution wa…

silica xerogel boson peak inelastic neutron scattering excess density of states LDL->HDL transition mean square displacements elastic neutron scattering protein dynamical transitionSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)
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Localized surface plasmon resonance in silver nanoparticles: Atomistic first-principles time-dependent density-functional theory calculations

2015

We observe using ab initio methods that localized surface plasmon resonances in icosahedral silver nanoparticles enter the asymptotic region already between diameters of 1 and 2 nm, converging close to the classical quasistatic limit around 3.4 eV. We base the observation on time-dependent density-functional theory simulations of the icosahedral silver clusters Ag$_{55}$ (1.06 nm), Ag$_{147}$ (1.60 nm), Ag$_{309}$ (2.14 nm), and Ag$_{561}$ (2.68 nm). The simulation method combines the adiabatic GLLB-SC exchange-correlation functional with real time propagation in an atomic orbital basis set using the projector-augmented wave method. The method has been implemented for the electron structure…

silver nanoparticlesMaterials scienceta221Ab initioFOS: Physical sciencesMetal nanoparticlesMolecular physicsAtomic orbitalTime-dependent density functional theorySurface plasmon resonanceta116ta218Basis setPlasmonCondensed Matter - Materials Scienceta214ta114Condensed matter physicsMaterials Science (cond-mat.mtrl-sci)Time-dependent density functional theoryCondensed Matter PhysicsNanoshellElectronic Optical and Magnetic MaterialsPlasmonicssurface plasmon resonanceLocalized surface plasmonPhysical Review B
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Compost Amendment Impact on Soil Physical Quality Estimated from Hysteretic Water Retention Curve

2022

Capacity-based indicators of soil physical quality (SPQ) and pore distribution parameters were proposed to assess the effects of compost amendment but their determination was limited to desorption water retention experiments. This study also considered the pore size distribution obtained from adsorption experiments to establish the effectiveness of compost amendment in modifying the physical and hydrological attributes of a sandy loam soil. Repacked soil samples with different compost to soil ratios, r, were subjected to a wetting–drying cycle, and the water retention data were fit to the van Genuchten model to obtain the pore volume distribution functions. The soil bulk density was m…

soil structure pore volume distribution function bulk density macroporosity air capacity plant available water capacity relative field capacity S-indexGeography Planning and Developmentsoil structure; pore volume distribution function; bulk density; macroporosity; air capacity; plant available water capacity; relative field capacity; S-indexSettore AGR/08 - Idraulica Agraria E Sistemazioni Idraulico-ForestaliAquatic ScienceBiochemistryWater Science and Technology
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Intergenerational fitness effects of the early life environment in a wild rodent

2019

The early life environment can have profound, long‐lasting effects on an individual's fitness. For example, early life quality might (a) positively associate with fitness (a silver spoon effect), (b) stimulate a predictive adaptive response (by adjusting the phenotype to the quality of the environment to maximize fitness) or (c) be obscured by subsequent plasticity. Potentially, the effects of the early life environment can persist beyond one generation, though the intergenerational plasticity on fitness traits of a subsequent generation is unclear. To study both intra‐ and intergenerational effects of the early life environment, we exposed a first generation of bank voles to two early life…

sopeutuminenmaternal effectpredictive adaptive responseintergenerational plasticitymetsämyyräympäristötekijätfungipopulaatiodynamiikkasocial environmentsilver spoonsosiaalinen ympäristöearly lifefenotyyppiprotein restrictionpopulation densityasukastiheyskunto
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Early life of fathers affects offspring fitness in a wild rodent

2019

Intergenerational fitness effects on offspring due to the early life of the parent are well studied from the standpoint of the maternal environment, but intergenerational effects owing to the paternal early life environment are often overlooked. Nonetheless, recent laboratory studies in mammals and ecologically relevant studies in invertebrates predict that paternal effects can have a major impact on the offspring's phenotype. These non‐genetic, environment‐dependent paternal effects provide a mechanism for fathers to transmit environmental information to their offspring, and could allow rapid adaptation. We used the bank vole Myodes glareolus, a wild rodent species with no paternal care, t…

sopeutuminenmetsämyyräfungiepigeneettinen periytyminenearly life environmentadaptationfitnessravintopaternal effectintergenerational effectsprotein restricted dietMyodes glareoluswinter survivaljälkeläisetelinympäristöpopulation densitysocial confrontationhenkiinjääminen
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Adaptation of bone to physical activity and diet-induced obesity

2011

sopeutuminenobesityluustorakennebone structureluuphysical activityluuntiheysadaptationliikuntabonelihavuusmineral densityfyysinen aktiivisuus
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Models and methods for space and space-time interactions in complex point processes with applications on earthquakes

spatial covariatespatial point processeearthquakes; hybrids of Gibbs point processes; spatial covariates; spatial point processes; hypothesis testing; local indicators of spatio-temporal association; permutation-based tests; second-order product density function; log-Gaussian Cox process; spatial anisotropy; spatio-temporal point process; clustering detectionlog-Gaussian Cox proceearthquakehybrids of Gibbs point processehypothesis testinglocal indicators of spatio-temporal associationpermutation-based testspatial anisotropysecond-order product density functionspatio-temporal point proceSettore SECS-S/01 - Statisticaclustering detection
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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…

spin accumulationspin currenttransport propertiessuperfluid densityCondensed Matter::SuperconductivityCondensed Matter::Strongly Correlated Electronsspin relaxationsuprajohteet
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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 densityNBOsupramolekulaarinen kemiakompleksiyhdisteetpyrazolyl-s-triazineCu(II)Co(II)Hirshfeld
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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…

stable processe[SPI] Engineering Sciences [physics]spectral densityJackson kernel[MATH] Mathematics [math][INFO] Computer Science [cs]
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