10,665 research outputs found
Kinetics of photoinduced matter transport driven by intensity and polarization in thin films containing azobenzene
We investigate the kinetics of photoinduced deformation phenomena in azobenzene-containing thin solid films. We show that a light intensity pattern and a light polarization pattern produce two distinct material transport processes whose direction and kinetics can be independently controlled. The kinetics of the intensity-driven deformation scales with the incoming light power while the kinetics of the polarization-driven mass transport scales with the amplitude of the electromagnetic field pattern. We conclude that these two processes are fully independent one from the other and originate from two different microscopic mechanisms
Zero Energy of Plane-Waves for ELKOs
We consider the ELKO field in interaction through contorsion with its own
spin density, and we investigate the form of the consequent autointeractions;
to do so we take into account the high-density limit and find plane wave
solutions: such plane waves give rise to contorsional autointeractions for
which the Ricci metric curvature vanishes and therefore the energy density is
equal to zero identically. Consequences are discussed.Comment: 7 page
Microarray sub-grid detection: A novel algorithm
This is the post print version of the article. The official published version can be obtained from the link below - Copyright 2007 Taylor & Francis LtdA novel algorithm for detecting microarray subgrids is proposed. The only input to the algorithm is the raw microarray image, which can be of any resolution, and the subgrid detection is performed with no prior assumptions. The algorithm consists of a series of methods of spot shape detection, spot filtering, spot spacing estimation, and subgrid shape detection. It is shown to be able to divide images of varying quality into subgrid regions with no manual interaction. The algorithm is robust against high levels of noise and high percentages of poorly expressed or missing spots. In addition, it is proved to be effective in locating regular groupings of primitives in a set of non-microarray images, suggesting potential application in the general area of image processing
On the consistency of Constraints in Matter Field Theories
We consider how the principles of causality and equivalence restrict the
background in which matter field theories are defined; those constraints
develop in restrictions for these matter field theories: the simplest matter
field theory aside, all other less simple matter field theories are too complex
therefore resulting to be inconsistent in general instances.Comment: 10 page
Effect of facade reflectance on outdoor microclimate: An Italian case study
Global warming affects the built environment with relation to its own characteristics, form, density. Heat waves effects would have limited effects if most of the cities would not be affected by Urban Heat Island that strongly increase their impacts (particularly on urban population). Does the choice of façade colours and materials contribute to this issue? The paper reports a research on a case study in Italy that tries to answer to this question comparing the trend in outdoor temperature increase closed to the building façade with relation to its colour and reflectance variations modelled by using Envi-met software. The outcomes point out that there is a correlation between the building façade reflectance and the temperature trend but this has a very limited influence on outdoor microclimate in open spaces as it varies in a range of less than 1°C
Late-time Light Curves of Type II Supernovae: Physical Properties of SNe and Their Environment
We present BVRIJHK band photometry of 6 core-collapse supernovae, SNe 1999bw,
2002hh, 2003gd, 2004et, 2005cs, and 2006bc measured at late epochs (>2 yrs)
based on Hubble Space Telescope (HST), Gemini north, and WIYN telescopes. We
also show the JHK lightcurves of a supernova impostor SN 2008S up to day 575.
Of our 43 HST observations in total, 36 observations are successful in
detecting the light from the SNe alone and measuring magnitudes of all the
targets. HST observations show a resolved scattered light echo around SN 2003gd
at day 1520 and around SN 2002hh at day 1717. Our Gemini and WIYN observations
detected SNe 2002hh and 2004et, as well. Combining our data with previously
published data, we show VRIJHK-band lightcurves and estimate decline magnitude
rates at each band in 4 different phases. Our prior work on these lightcurves
and other data indicate that dust is forming in our targets from day ~300-400,
supporting SN dust formation theory. In this paper we focus on other physical
properties derived from the late time light curves. We estimate 56Ni masses for
our targets (0.5-14 x 10^{-2} Msun) from the bolometric lightcurve of each for
days ~150-300 using SN 1987A as a standard (7.5 x 10^{-2} Msun). The flattening
or sometimes increasing fluxes in the late time light curves of SNe 2002hh,
2003gd, 2004et and 2006bc indicate the presence of light echos. We estimate the
circumstellar hydrogen density of the material causing the light echo and find
that SN 2002hh is surrounded by relatively dense materials (n(H) >400 cm^{-3})
and SNe 2003gd and 2004et have densities more typical of the interstellar
medium (~1 cm^{-3}). The 56Ni mass appears well correlated with progenitor mass
with a slope of 0.31 x 10^{-2}, supporting the previous work by Maeda et al.
(2010), who focus on more massive Type II SNe. The dust mass does not appear to
be correlated with progenitor mass.Comment: We corrected the 56Ni mass of SN2005cs and Figures 8 (a) and 8 (c
Resolving the M2-brane
We construct deformed, T^2 wrapped, rotating M2-branes on a resolved cone
over Q^{1,1,1} and Q^{1,1,1}/Z_2, as well as on a product of two Eguchi-Hanson
instantons. All worldvolume directions of these supersymmetric and regular
solutions are fibred over the transverse space. These constitute gravity duals
of D=3, N=2 gauge theories. In particular, the deformed M2-brane on a resolved
cone over Q^{1,1,1} and the S^1 wrapped M2-brane on a resolved cone over
Q^{1,1,1}/Z_2 provide explicit realizations of holographic renormalization
group flows in M-theory for which both conformal and Lorentz symmetries are
broken in the IR region and restored in the UV limit. These solutions can be
dualized to supersymmetric type IIB pp-waves, which are rendered non-singular
either by additional flux or a twisted time-like direction.Comment: Latex, 23 pages, references adde
The use of building performance simulation to support architectural design: a case study
Abstract Considering the complex interaction between energy performance, lighting, acoustic and thermal comfort in contemporary design, building performance simulation [BPS] shall play a key role in addressing decision making process and technical choices towards optimized configuration during the whole design phase. The paper reports the outcomes of a case study â performed in the framework of Ma Final Design Lab at the Department of Architecture, University of Bologna â where BPS was adopted from the very beginning as a tool to support the design process from the concept validation to the final architectural configuration to fit with passive house standards
Imaging Circuit Activity in the Rat Brain with Fast Neural EIT and Depth Arrays
Few techniques are specialized for neuroscience at the 'mesoscopic' level of neural circuits. Fast neural electrical impedance tomography (fnEIT) is a novel imaging technique that offers affordability, portability, and high spatial (âŒ100 ÎŒm) and temporal (1 ms) resolution. fnEIT with depth arrays offers the opportunity to study the dynamics of circuits in the brains of animal models. However, current depth array geometries are not optimized for this imaging modality. They feature small, closely packed electrodes with high impedance that do not provide sufficient SNR for high resolution EIT image reconstruction. They also have a highly limited range. It is necessary to develop depth arrays suitable for fnEIT and evaluate their performance in a representative setting for circuit neuroscience. In this study, we optimized the geometry of depth arrays for fnEIT, and then investigated the prospects of imaging thalamocortical circuit activity in the rat brain. Optimization was consistent with the hypothesis that small, closely spaced electrodes were not suitable for fnEIT. In vivo experiments with the optimized geometry then showed that fnEIT can image thalamocortical circuit activity at a high enough resolution to see the activity propagating from specific thalamic nuclei to specific regions of the somatosensory cortex. This bodes well for fnEIT's potential as a technique for circuit neuroscience
- âŠ