3,422 research outputs found
The origins of media trust in a young democracy
Declining trust in news media has often been recognized as one of the major challenges facing modern journalism with potentially detrimental consequences for democratic processes. In this article, we examine the predictive potential of cultural-political and performance factors on public trust in news media in the context of a young democracy. Specifically, we have analyzed to what extent citizens’ populist attitudes and perceptions of journalistic roles relate to the levels of media trust using data from an online survey of Serbian respondents (N = 200). The findings showed that support for populism did not significantly predict trust in news media in general after controlling for relevant factors, most importantly political trust. However, populist attitudes were found to be related to the amount of trust citizens have in distinct types of news media –i.e., those who support populism exhibited less trust in public broadcasters than in online news outlets. The analyses also revealed that the more Serbian citizens perceived news media as being successful at performing interpretive and mobilizing roles, the more trust they placed in the media
Probing neutrino oscillations jointly in long and very long baseline experiments
We examine the prospects of making a joint analysis of neutrino oscillation
at two baselines with neutrino superbeams. Assuming narrow band superbeams and
a 100 kt water Cerenkov calorimeter, we calculate the event rates and
sensitivities to the matter effect, the signs of the neutrino mass differences,
the CP phase and the mixing angle \theta_{13}. Taking into account all possible
experimental errors under general consideration, we explored the optimum cases
of narrow band beam to measure the matter effect and the CP violation effect at
all baselines up to 3000 km. We then focus on two specific baselines, a long
baseline of 300 km and a very long baseline of 2100 km, and analyze their joint
capabilities. We found that the joint analysis can offer extra leverage to
resolve some of the ambiguities that are associated with the measurement at a
single baseline.Comment: 23 pages, 11 figure
NEW MEMBERS OF THE PERTUSARIALES (ASCOMYCOTA) PROVED BY COMBINED PHYLOGENETIC ANALYSIS
New genus Marfl oraea for the “Variolaria” amara-group as well as new members of the genera Dibaeis and Ochrolechia proved by results of the combined phylogenetic analysis based on
nuclear ITS1/ITS2 portion of ribosomal nrDNA and 12S SSU mtDNA sequences are described and compared with closely related taxa. Fift een new combinations are proposed, i.e. Dibaeis yurii,
Marfl oraea albescens, M. amara, M. aspergilla, M. corallina, M. corallophora, M. erythrella, M. excludens, M. mammosa, M. ophthalmiza, M. panyrga, M. pulvinata, M. scaberula, M. subventosa and Ochrolechia dactylina. Dibaeis yurii is recorded for the fi rst time from South Korea
Higgs Structures of Dyonic Instantons
We study Higgs field configurations of dyonic instantons in spontaneously
broken (4+1)-dimensional Yang-Mills theory. The adjoint scalar field solutions
to the covariant Laplace equation in the ADHM instanton background are
constructed in general noncanonical basis, and they are used to study
explicitly the Higgs field configurations of dyonic instantons when the gauge
fields are taken by Jackiw-Nohl-Rebbi instanton solutions. For these solutions
corresponding to small instanton number we then consider in some detail the
zero locus of the Higgs field, which describes the cross section of supertubes
connecting parallel D4-branes in string theory. Also the information on the
Higgs zeroes is used to discuss the residual gauge freedom concerning the
Jackiw-Nohl-Rebbi solutions.Comment: 1+27 pages, 6 figure
Heisenberg-picture approach to the exact quantum motion of a time-dependent forced harmonic oscillator
In the Heisenberg picture, the generalized invariant and exact quantum
motions are found for a time-dependent forced harmonic oscillator. We find the
eigenstate and the coherent state of the invariant and show that the
dispersions of these quantum states do not depend on the external force. Our
formalism is applied to several interesting cases.Comment: 15 pages, two eps files, to appear in Phys. Rev. A 53 (6) (1996
Hydrogen effects on nanomechanical behavior of additively manufactured 316L stainless steels
Additive manufacturing (AM) has received considerable attention in recent years due to its ability to produce complex engineering components with reduced cost and waste, which simply cannot be made with conventional manufacturing processes. It has been reported that AM 316L austenitic stainless steel (SS) has excellent mechanical properties and possibly even breaks the strength-ductility trade-off. For practical industrial application, it is necessary to investigate the AM steel\u27s resistance to hydrogen embrittlement which is unavoidable in most strucral applications. In this work, we explore the hydrogen effects on nanomechanical responses of AM 316L SS (such as hardness, strain rate sensitivity, activation volume). The obtained results will be compared with those of conventional 316L SS and discussed in terms of hydrogen effect on plastic deformation and microstructure.
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Velocity-resolved high-J CO emission from massive star-forming clumps
(Abridged) Context. Massive star formation is associated with energetic
processes, which result in significant gas cooling via far-infrared (IR) lines.
Velocity-resolved observations can constrain the kinematics of the gas,
allowing the identification of the physical mechanisms responsible for gas
heating. Aims. Our aim is to quantify far-infrared CO line emission toward
high-mass star-forming regions, identify the high-velocity gas component
associated with outflows, and estimate the physical conditions required for the
excitation of the observed lines. Methods. Velocity-resolved SOFIA/GREAT
spectra of 13 high-mass star forming clumps of various luminosities and
evolutionary stages are studied using CO 11-10 and 16-15 lines. Results. All
targets show strong high-J CO emission in the far-IR, characterized by broad
line wings associated with outflows, thereby significantly increasing the
sample of sources with velocity-resolved high-J CO spectra. The contribution of
the emission in the line wings does not correlate with the envelope mass or
evolutionary stage. Gas rotational temperatures cover a narrow range of 120-220
K for the line wings. The non-LTE radiative transfer models indicate gas
densities of 1e5-1e7 cm-3 and N(CO) of 1e17- 1e18 cm-2, similar to physical
conditions in deeply-embedded low- and high-mass protostars. The
velocity-integrated CO line fluxes correlate with the bolometric luminosity
over 7 orders of magnitude including data on the low-mass protostars,
suggesting similar processes are responsible for the high-J CO excitation over
a significant range of physical scales. Conclusions. Velocity-resolved line
profiles allow the detection of outflows toward massive star-forming clumps
spanning a broad range of evolutionary stages. The lack of clear evolutionary
trends suggest that mass accretion and ejection prevail during the entire
lifetime of star-forming clumps.Comment: 21 pages, 19 figures, accepted to A&
Towards 5D Grand Unification without SUSY Flavor Problem
We consider the renormalization group approach to the SUSY flavor problem in
the supersymmetric SU(5) model with one extra dimension. In higher dimensional
SUSY gauge theories, it has been recently shown that power corrections due to
the Kaluza-Klein states of gauge fields run the soft masses generated at the
orbifold fixed point to flavor conserving values in the infra-red limit. In
models with GUT breaking at the brane where the GUT scale can be larger than
the compactification scale, we show that the addition of a bulk Higgs
multiplet, which is necessary for the successful unification, is compatible
with the flavor universality achieved at the compactification scale.Comment: JHEP style file of 35 pages with 3 figures, Version to appear in JHE
Nematic twist-bend phase with nanoscale modulation of molecular orientation
A state of matter in which molecules show a long-range orientational order and no positional order is called a nematic liquid crystal. The best known and most widely used (for example, in modern displays) is the uniaxial nematic, with the rod-like molecules aligned along a single axis, called the director. When the molecules are chiral, the director twists in space, drawing a right-angle helicoid and remaining perpendicular to the helix axis; the structure is called a chiral nematic. Here using transmission electron and optical microscopy, we experimentally demonstrate a new nematic order, formed by achiral molecules, in which the director follows an oblique helicoid, maintaining a constant oblique angle with the helix axis and experiencing twist and bend. The oblique helicoids have a nanoscale pitch. The new twist-bend nematic represents a structural link between the uniaxial nematic (no tilt) and a chiral nematic (helicoids with right-angle tilt)
Towards spin-polarized two-dimensional electron gas at a surface of an antiferromagnetic insulating oxide
The surfaces of transition-metal oxides with the perovskite structure are fertile grounds for the discovery of novel electronic and magnetic phenomena. In this article, we combine scanning transmission electron microscopy (STEM) with density functional theory (DFT) calculations to obtain the electronic and magnetic properties of the (001) surface of a
(
LaFe
O
3
)
8
/
(
SrFe
O
3
)
1
superlattice film capped with four layers of
LaFe
O
3
. Simultaneously acquired STEM images and electron-energy-loss spectra reveal the surface structure and a reduction in the oxidation state of iron from
F
e
3
+
in the bulk to
F
e
2
+
at the surface, extending over several atomic layers, which signals the presence of oxygen vacancies. The DFT calculations confirm the reduction in terms of oxygen vacancies and further demonstrate the stabilization of an exotic phase in which the surface layer is half metallic and ferromagnetic, while the bulk remains antiferromagnetic and insulating. Based on the calculations, we predict that the surface magnetism and conductivity can be controlled by tuning the partial pressure of oxygen
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