Search results for "mass [rho(770)]"
showing 10 items of 416 documents
Long-term phytoplankton changes in a shallow hypertrophic lake, Albufera of Valencia (Spain)
1994
A long-term phytoplankton study was carried out in the Albufera of Valencia, a shallow hypertrophic lake (surface area 21 km2, mean depth 1 m, total inorganic nitrogen load 155 g m-2 y-1, total inorganic phosphate load 15 g m-2 y-1) from 1980 to 1988. The lake functions as a reservoir for the surrounding rice cultivation. From 1940's to 1988, its phytoplankton assemblage has been altered from a mesotrophic to a hypertrophic character, as consequence of the increasing pollution. For 1980–88, annual variations in the phytoplankton were less pronounced than seasonal changes. The hypertrophic and morphometric features of the lake favoured the stability of the phytoplankton assemblage and chloro…
Long-term zoobenthos variability in the Gulf of Riga in relation to climate variability
2001
Abstract Macrozoobenthos data were collected three times a year from 1979 to 1996 in the Gulf of Riga, Eastern Baltic Sea. Interannual variability of the abundance and biomass of benthic fauna at coastal and offshore areas was related to climate variability using a multivariate regression model. The results suggest that the interannual variability of macrozoobenthos biomass at the offshore station in spring is controlled by the climate variability during winter-time. No correlations to large-scale climate pattern have been detected for other seasons and for the coastal region. An analysis of river runoff, nitrogen, and phosphorus data of the River Daugava indicates that the anthropogenic in…
Black hole-neutron star coalescence: effects of the neutron star spin on jet launching and dynamical ejecta mass
2020
Black hole-neutron star (BHNS) mergers are thought to be sources of gravitational waves (GWs) with coincident electromagnetic (EM) counterparts. To further probe whether these systems are viable progenitors of short gamma-ray bursts (sGRBs) and kilonovae, and how one may use (the lack of) EM counterparts associated with LIGO/Virgo candidate BHNS GW events to sharpen parameter estimation, we study the impact of neutron star spin in BHNS mergers. Using dynamical spacetime magnetohydrodynamic simulations of BHNSs initially on a quasicircular orbit, we survey configurations that differ in the BH spin ($a_{\rm BH}/M_{\rm BH}=0$ and $0.75$), the NS spin ($a_{\rm NS}/M_{\rm NS}=-0.17,\,0,\,0.23$ a…
Quantum-well states in ultrathin Ag(111) films deposited onto H-passivated Si(111)-(1x1) surfaces
2002
Ag(111) films were deposited at room temperature onto H-passivated Si(111)-(1x1) substrates, and subsequently annealed at 300 C. An abrupt non-reactive Ag/Si interface is formed, and very uniform non-strained Ag(111) films of 6-12 monolayers have been grown. Angle resolved photoemission spectroscopy has been used to study the valence band electronic properties of these films. Well-defined Ag sp quantum-well states (QWS) have been observed at discrete energies between 0.5-2eV below the Fermi level, and their dispersions have been measured along the GammaK, GammaMM'and GammaL symmetry directions. QWS show a parabolic bidimensional dispersion, with in-plane effective mass of 0.38-0.50mo, along…
Atomic lattice excitons: from condensates to crystals
2007
We discuss atomic lattice excitons (ALEs), bound particle-hole pairs formed by fermionic atoms in two bands of an optical lattice. Such a system provides a clean setup to study fundamental properties of excitons, ranging from condensation to exciton crystals (which appear for a large effective mass ratio between particles and holes). Using both mean-field treatments and 1D numerical computation, we discuss the properities of ALEs under varying conditions, and discuss in particular their preparation and measurement.
Magnetic quantum criticality in quasi-one-dimensional Heisenberg antiferromagnet Cu (C4H4N2)( NO 3)2
2016
We analyze exciting recent measurements [Phys. Rev. Lett. 114 (2015) 037202] of the magnetization, differential susceptibility and specific heat on one dimensional Heisenberg antiferromagnet Cu(C4H4N2)(NO3)2 (CuPzN) subjected to strong magnetic fields. Using the mapping between magnons (bosons) in CuPzN and fermions, we demonstrate that magnetic field tunes the insulator towards quantum critical point related to so-called fermion condensation quantum phase transition (FCQPT) at which the resulting fermion effective mass diverges kinematically. We show that the FCQPT concept permits to reveal the scaling behavior of thermodynamic characteristics, describe the experimental results quantitativ…
Dipole surface plasmon in K+N clusters
1992
Abstract The technique of sum rules has been used to investigate the dipole surface plasmon for K + N clusters within a Density Functional Theory and the spherical jellium model. The role played by non-local effects is discussed comparing the results obtained from different functionals. Band-structure and core-polarization effects have been phenomenologically included in the calculation by means of an electron effective mass and a dielectric constant. Comparison with recent experimental data is presented.
Effects of continuous and rotational grazing of different forage species on ewe milk production
2012
Abstract The aim of this research was to evaluate the effects of continuous and rotational grazing of different forage species on milk production in ewes. The forage species were chicory (Cichorium intybus L.), a mixture of oat (Avena sativa L.) and berseem clover (Trifolium alexandrinum L.), and sulla (Hedysarum coronarium L.). Forty ewes were divided into 5 groups, and subjected to one of the following treatments: continuous grazing on chicory, continuous grazing on the mixture, continuous grazing on sulla, rotational grazing on the mixture, or rotational grazing on sulla. Among the species continuously grazed, chicory showed a lower biomass than the mixture, or sulla. Ewes grazing chicor…
Optimal damping coefficient for a class of continuous contact models
2020
AbstractIn this study, we develop an analytical formula to approximate the damping coefficient as a function of the coefficient of restitution for a class of continuous contact models. The contact force is generated by a logical point-to-point force element consisting of a linear damper connected in parallel to a spring with Hertz force–penetration characteristic, while the exponent of deformation of the Hertz spring can vary between one and two. In this nonlinear model, it is assumed that the bodies start to separate when the contact force becomes zero. After separation, either the restitution continues or a permanent penetration is achieved. Therefore, this model is capable of addressing …
Effect of a 3-week body mass reduction program on body composition, muscle function and motor performance in pubertal obese boys and girls
2005
The aim of this study was to investigate the effects of a multidisciplinary body mass reduction (BMR) program on body composition, muscle function and motor performance in 50 obese [mean body mass index (BMI): 35.9+/-5.8 kg/m2] boys and girls aged 12-17 yr (Tanner stage III, IV and V). The hospital-based BMR program combined an energy-restricted diet (1400-1600 kcal), nutritional education, psychological counselling and moderate physical activity (45-60 min/ session; 5 sessions/week; 60-80% of the maximal heart rate) during a 3-week period. Fat mass, fat-free mass, maximal power during jumping and stair climbing as well as maximal strength of the upper and lower limb muscles were quantified…