1,795 research outputs found
Changes in loneliness and coping strategies during COVID-19
The social distancing measures implemented to slow the spread of COVID-19 impacted many aspects of people's lives. Previous research has reported negative consequences of these measures for people's psychological well-being, and that people differed in the impact on their psychological well-being. The present study aimed to describe the different coping strategies Dutch people used to deal with these measures and to link these strategies to loneliness. In addition, the study aimed to examine mean-level changes in loneliness and to explore individual differences in loneliness change. We used data from 2009 participants of a panel study of representative Dutch households. We assessed coping strategies used during the first wave of the COVID-19 pandemic in May 2020 and examined changes in loneliness between October 2019 (before COVID-19) and May 2020 (during the first wave of COVID-19). First, results showed that most people employed specific coping strategies. The most frequently used social strategies were chatting and (video)calling; the most frequently used non-social strategies were going outside, doing chores, watching TV, reading and self-care. Second, people who used more coping strategies reported lower levels of loneliness. Third, analyses revealed an average increase in loneliness between October 2019 and May 2020. Fourth, we observed two significant interaction effects, showing a stronger positive link between the number of social coping strategies and initial loneliness levels among those with a partner or living with others than for those who were single or lived alone. Yet, no moderating effects on changes in loneliness were found: people using more coping strategies did not differ in loneliness changes from people using fewer coping strategies. Together, findings suggest that loneliness increased in the Netherlands during the first phase of COVID-19 and that, while people's coping strategies were related to loneliness levels, they did not buffer against loneliness increases
Effects of geometric anisotropy on local field distribution: Ewald-Kornfeld formulation
We have applied the Ewald-Kornfeld formulation to a tetragonal lattice of
point dipoles, in an attempt to examine the effects of geometric anisotropy on
the local field distribution. The various problems encountered in the
computation of the conditionally convergent summation of the near field are
addressed and the methods of overcoming them are discussed. The results show
that the geometric anisotropy has a significant impact on the local field
distribution. The change in the local field can lead to a generalized
Clausius-Mossotti equation for the anisotropic case.Comment: Accepted for publications, Journal of Physics: Condensed Matte
Diffusive transport of light in three-dimensional disordered Voronoi structures
The origin of diffusive transport of light in dry foams is still under
debate. In this paper, we consider the random walks of photons as they are
reflected or transmitted by liquid films according to the rules of ray optics.
The foams are approximately modeled by three-dimensional Voronoi tessellations
with varying degree of disorder. We study two cases: a constant intensity
reflectance and the reflectance of thin films. Especially in the second case,
we find that in the experimentally important regime for the film thicknesses,
the transport-mean-free path does not significantly depend on the topological
and geometrical disorder of the Voronoi foams including the periodic Kelvin
foam. This may indicate that the detailed structure of foams is not crucial for
understanding the diffusive transport of light. Furthermore, our theoretical
values for transport-mean-free path fall in the same range as the experimental
values observed in dry foams. One can therefore argue that liquid films
contribute substantially to the diffusive transport of light in {dry} foams.Comment: 8 pages, 8 figure
Electromagnetically induced transparency in cold 85Rb atoms trapped in the ground hyperfine F = 2 state
We report electromagnetically induced transparency (EIT) in cold 85Rb atoms,
trapped in the lower hyperfine level F = 2, of the ground state 5
(Tiwari V B \textit{et al} 2008 {\it Phys. Rev.} A {\bf 78} 063421). Two steady
state -type systems of hyperfine energy levels are investigated using
probe transitions into the levels F = 2 and F = 3 of the
excited state 5 in the presence of coupling transitions F = 3
F = 2 and F = 3 F = 3, respectively. The
effects of uncoupled magnetic sublevel transitions and coupling field's Rabi
frequency on the EIT signal from these systems are studied using a simple
theoretical model.Comment: 12 pages, 7 figure
Recuperative system for high and ultra-high temperature flue gases. Final report
Advanced recuperative system technology for high and ultra-high temperature flue gases was investigated. Several high temperature recuperator system and component concepts were evolved and studied for the purpose of finding the schemes and designs that attain maximum fuel savings. The most promising concepts for industrial application were pre-engineered further to devise designs for adaptation to existing steel mills. The principal effort was aimed at steel soaking pit applications. The concept which provides the highest air preheat temperatures and the largest fuel savings for soaking pit application utilizing basic state-of-the-art technology is a low air pressure ceramic recuperator operated in conjunction with a higher air pressure metallic recuperator. This concept has the additional advantage that higher air pressures can be attained at the burner than can be attained with an all ceramic recuperator. These higher air pressures are required for high momentum, high efficiency burner performance, resulting in improved productivity and additional fuel savings. The technical feasibility of applying this high temperature recuperation system to existing soaking pits was established
On the exact electric and magnetic fields of an electric dipole
We derive from Jefimenko's equations a multipole expansion in order to obtain
the exact expressions for the electric and magnetic fields of an electric
dipole with an arbitrary time dependence. A few comments are also made about
the usual expositions found in most common undergraduate and graduate textbooks
as well as in the literature on this topic
Implications of Pseudospin Symmetry on Relativistic Magnetic Properties and Gamow - Teller Transitions in Nuclei
Recently it has been shown that pseudospin symmetry has its origins in a
relativistic symmetry of the Dirac Hamiltonian. Using this symmetry we relate
single - nucleon relativistic magnetic moments of states in a pseudospin
doublet to the relativistic magnetic dipole transitions between the states in
the doublet, and we relate single - nucleon relativistic Gamow - Teller
transitions within states in the doublet. We apply these relationships to the
Gamow - Teller transitions from to its mirror nucleus .Comment: 17 pages, 2 figures, to be published in PRC. Slightly revised text
with one reference adde
Quark-Hadron Duality in Neutron (3He) Spin Structure
We present experimental results of the first high-precision test of
quark-hadron duality in the spin-structure function g_1 of the neutron and
He using a polarized 3He target in the four-momentum-transfer-squared range
from 0.7 to 4.0 (GeV/c)^2. Global duality is observed for the spin-structure
function g_1 down to at least Q^2 = 1.8 (GeV/c)^2 in both targets. We have also
formed the photon-nucleon asymmetry A_1 in the resonance region for 3He and
found no strong Q^2-dependence above 2.2 (GeV/c)^2.Comment: 13 pages, 3 figure
The powdery mildew-resistant Arabidopsis <em>mlo2 mlo6 mlo12</em> triple mutant displays altered infection phenotypes with diverse types of phytopathogens
Moments of the neutron structure function at intermediate
We present new experimental results of the He spin structure function
in the resonance region at values between 1.2 and 3.0 (GeV/c).
Spin dependent moments of the neutron were then extracted. Our main result, the
resonance contribution to the neutron matrix element, was found to be
small at =2.4 (GeV/c) and in agreement with the Lattice QCD
calculation. The Burkhardt-Cottingham sum rule for He and the neutron was
tested with the measured data and using the Wandzura-Wilczek relation for the
low unmeasured region. A small deviation was observed at values
between 0.5 and 1.2 (GeV/c) for the neutron
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