1,297 research outputs found
Macroscopic collectivity on microscopic base in living systems
The collective phenomena in living systems is discussed on the dynamic frustration
basis.
The frustrated connection is introduced on all the organising levels of the living
phenomenon:
· for water states (proton migration),
· for proteins and protein-structures (metabolic charge transfer),
· for cells (membrane states and ordering),
· for tissues (social signals),
· for organs and organism (overall transport problems).
It is shown, that the cancer-genesis is tightly connected with the failure of the
collectivity in the system. The relevant mechanisms of the collectivity is analised in
details for the better understanding the malignant tumor development
Evaluation of laminated structures for sports mouthguards
Most of the past studies have concentrated on the properties of mouthguard materials rather than their ability to protect the underlying substructure. Previous work has indicated that the incorporation of a shook absorbing layer into the sports mouthguard reduces the likelihood of injury to the head, neck and oral cavity of the wearer, The purpose of this study is to develop an optimum laminated structure that protects an easily deformable structure during an impact.
Dropweight impact tests were conducted on a series of moulded samples which were circularly clamped and force-time and displacement-time plots obtained, Single thickness specimens of ethylene vinyl acetate (EVA), 1-5mm thick were compared with laminated structures of EVA, incorporating 1mm thick layers of polymethylmethacrylate (PMMA) and a silicone or synthetic rubber up to a thickness of 5mm. It was observed that the multi-layered structures exhibited less deformation thereby transmitting less of the harmful effects through the laminate. It was concluded that laminated systems for mouthguards using different materials appear to offer better protection to the wearer
Emission Lines in the Spectrum of the 3He Star 3 Cen A
Emission in the 4d - 4f transitions of MnII (multiplet 13, 6122-6132 Ang), in
the 4f - 6g transitions of PII, and in 6149.5 Ang of HgII has been detected in
the spectrum of the helium weak star 3 Centauri A (B5 III-IVp). Weaker emission
from the same MnII multiplet is also seen in the hot, mild HgMn star 46 Aquila
(B9 III).It is suggested that the emission is of photospheric origin and may be
evidence for the stratification of manganese, phosphorus and mercury in the
photosphere of 3 CenA, and of manganese in 46Aql.Comment: 16 pages, 3 figure
Radiative transfer in moving media II. Solution of the radiative transfer equation in axial symmetry
A new method for the formal solution of the 2D radiative transfer equation in
axial symmetry in the presence of arbitrary velocity fields is presented. The
combination of long and short characteristics methods is used to solve the
radiative transfer equation. We include the velocity field in detail using the
Local Lorentz Transformation. This allows us to obtain a significantly better
description of the photospheric region, where the gradient of the global
velocity is too small for the Sobolev approximation to be valid. Sample test
calculations for the case of a stellar wind and a rotating atmosphere are
presented.Comment: 11 pages, 19 figures. accepted by Astronomy and Astrophysic
CRISP Spectropolarimetric Imaging of Penumbral Fine Structure
We discuss penumbral fine structure in a small part of a pore, observed with
the CRISP imaging spectropolarimeter at the Swedish 1-m Solar Telescope (SST),
close to its diffraction limit of 0.16 arcsec. Milne-Eddington inversions
applied to these Stokes data reveal large variations of field strength and
inclination angle over dark-cored penumbral intrusions and a dark-cored light
bridge. The mid-outer part of this penumbra structure shows 0.3 arcsec wide
spines, separated by 1.6 arcsec (1200 km) and associated with 30 deg
inclination variations. Between these spines, there are no small-scale magnetic
structures that easily can be be identified with individual flux tubes. A
structure with nearly 10 deg more vertical and weaker magnetic field is seen
midways between two spines. This structure is co-spatial with the brightest
penumbral filament, possibly indicating the location of a convective upflow
from below.Comment: Accepted for publication in ApJL 17 Oct 2008. One Figure adde
Chromospheric Velocities of a C-class Flare
We use high spatial and temporal resolution observations from the Swedish
Solar Telescope to study the chromospheric velocities of a C-class flare
originating from active region NOAA 10969. A time-distance analysis is employed
to estimate directional velocity components in H-alpha and Ca II K image
sequences. Also, imaging spectroscopy has allowed us to determine flare-induced
line-of-sight velocities. A wavelet analysis is used to analyse the periodic
nature of associated flare bursts. Time-distance analysis reveals velocities as
high as 64 km/s along the flare ribbon and 15 km/s perpendicular to it. The
velocities are very similar in both the H-alpha and Ca II K time series.
Line-of-sight H-alpha velocities are red-shifted with values up to 17 km/s. The
high spatial and temporal resolution of the observations have allowed us to
detect velocities significantly higher than those found in earlier studies.
Flare bursts with a periodicity of approximately 60 s are also detected. These
bursts are similar to the quasi-periodic oscillations observed at hard X-ray
and radio wavelength data. Some of the highest velocities detected in the solar
atmosphere are presented. Line-of-sight velocity maps show considerable mixing
of both the magnitude and direction of velocities along the flare path. A
change in direction of the velocities at the flare kernel has also been
detected which may be a signature of chromospheric evaporation.Comment: Accepted for publication in Astronomy and Astrophysics, 5 figure
Maximum Entropy Limit of Small-scale Magnetic Field Fluctuations in the Quiet Sun
The observed magnetic field on the solar surface is characterized by a very
complex spatial and temporal behavior. Although feature-tracking algorithms
have allowed us to deepen our understanding of this behavior, subjectivity
plays an important role in the identification and tracking of such features. In
this paper, we continue studies Gorobets, A. Y., Borrero, J. M., & Berdyugina,
S. 2016, ApJL, 825, L18 of the temporal stochasticity of the magnetic field on
the solar surface without relying either on the concept of magnetic features or
on subjective assumptions about their identification and interaction. We
propose a data analysis method to quantify fluctuations of the line-of-sight
magnetic field by means of reducing the temporal field's evolution to the
regular Markov process. We build a representative model of fluctuations
converging to the unique stationary (equilibrium) distribution in the long time
limit with maximum entropy. We obtained different rates of convergence to the
equilibrium at fixed noise cutoff for two sets of data. This indicates a strong
influence of the data spatial resolution and mixing-polarity fluctuations on
the relaxation process. The analysis is applied to observations of magnetic
fields of the relatively quiet areas around an active region carried out during
the second flight of the Sunrise/IMaX and quiet Sun areas at the disk center
from the Helioseismic and Magnetic Imager on board the Solar Dynamics
Observatory satellite.Comment: 11 pages, 5 figures, The Astrophysical Journal Supplement Series
(accepted
- …