3,414 research outputs found
Unitarization of the Horocyclic Radon Transform on Homogeneous Trees
Following previous work in the continuous setup, we construct the
unitarization of the horocyclic Radon transform on a homogeneous tree X and we
show that it intertwines the quasi regular representations of the group of
isometries of X on the tree itself and on the space of horocycles.Comment: 16 pages, 3 figure
Inherent electronic trap states in TiO2 nanocrystals: effect of saturation and sintering
We report a quantum mechanical investigation on the nature of electronic trap states in realistic models of
individual and sintered anatase TiO2
nanocrystals (NCs) of ca. 3 nm diameter. We find unoccupied
electronic states of lowest energy to be localized within the central part of the NCs, and to originate
from under-coordinated surface Ti atoms lying mainly at the edges between the (100) and (101) facets.
These localized states are found at about 0.3–0.4 eV below the fully delocalized conduction band states,
in good agreement with both electrochemical and spectro-electrochemical results. The overall DensityOf-States (DOS) below the conduction band (CB) can be accurately fitted to an exponential distribution
of states, in agreement with capacitance data. Water molecules adsorbed on the NC surface raise the
energy and reduce the number of localized states, thus modifying the DOS. As a possible origin of
additional trap states, we further investigated the oriented attachment of two TiO2
NCs at various
possible interfaces. For the considered models, we found only minor differences between the DOS of
two interacting NCs and those of the individual constituent NCs. Our results point at the presence of
inherent trap states even in perfectly stoichiometric and crystalline TiO2
NCs due to the unavoidable
presence of under-coordinated surface Ti(IV) ions at the (100) facets
Evaluation of the Effects of Anxiety on Behaviour and Physiological Parameters in VR Fire Simulations
This study considers the use of virtual reality technologies both to evaluate the optimal exodus paths from buildings and to analyze the behaviour of people in emergencies through the monitoring of physiological parameters. The degree of realism with which VR devices can simulate highly anxiogenic scenarios is considered. The experimentation is carried out on a school building and tested through a pilot trial where saturation, blood pressure, heart rate as well as the time of exodus are monitored. The variations of the peak values of physiological parameters highlight the influence of anxiogenic elements in the participant's state of anxiety
Multidisciplinary Approach to Structural/Energy Diagnosis of Historical Buildings: A Case Study
Abstract A synergic approach for the investigations of the historical building performances - with reference to both the structural behavior and the energy performances for the space heating and cooling - is presented. The historical masonry building "Palazzo Bosco Lucarelli", located in Benevento, has been chosen as case study. The structural and energy analyses are carried out in parallel, especially during the identification of the building characteristics through tests and surveys in-situ. For the structural analysis - beyond examinations on materials - some dynamic tests have been used for better assessing a numerical Finite Element model necessary for the verification of the structure safety. Moreover, being necessary a structural refurbishment, also an energy retrofit could be realized. A rigorous evaluation procedure - aimed to guarantee the necessary reliability of numerical predictions - is performed in order to verify the technical and economical convenience of various energy retrofit solutions
Unitarization and Inversion Formulae for the Radon Transform Between Dual Pairs
We consider the Radon transform associated to dual pairs (X,\u39e) in the sense of Helgason, with X = G/K and \u39e = G/H, where G is a locally compact group and K and H are closed subgroups of G. Under some technical assumptions, we prove that if the quasi-regular representations of G acting on L2(X) and L2(\u39e) are irreducible, then the Radon transform admits a unitarization intertwining the two representations. If, in addition, the representations are square- integrable, we provide an inversion formula for the Radon transform based on the voice transform associated to these representations
Determination of pesticides in the respirable fraction of airborne particulate matter by high-performance liquid chromatography–tandem mass spectrometry
Potential harmful effects of pesticides include risks to human health of workers involved in the wet spray application in cultivated areas. Inhalation exposure depends on several factors including pesticide concentrations in the respirable fraction of airborne particulate matter (PM4). To ensure a high level of protection, the use of tractors with cabins provides protection against dust, aerosols, and vapors. Since tractors not providing maximum protection are still in use, PM4 was sampled during spreading operations in agricultural fields inside and outside tractor cabins. Sample preparation technique based on accelerated solvent extraction and solid-phase extraction cleanup was optimized before analysis of nine pesticides in PM4. Meptyldinocap, deltamethrin, myclobutanil, fluopyram, methoxyfenozide, dimethomorph, fluopicolide, cyflufenamid, and metrafenone were simultaneously determined by high-performance liquid chromatography–electrospray ionization–tandem mass spectrometry (HPLC–ESI–MS–MS). The results demonstrated the efficacy of the tractor cabs used in the sampling sites. © 2017 Taylor & Francis
energy refurbishment of a university building in cold italian backcountry part 2 sensitivity studies and optimization
Abstract The first part of this study provided a discussion about the methodological approach for designing energy refurbishment measures of buildings. The case study is a building owned by University of Molise, in Campobasso, a cold Italian city. The reference scenario is a numerical model built after deep investigations, and thus surveys, questionnaires, documents and experimental measurements on the real building. Then, a calibrated energy model was presented. In this second part, starting from the calibrated model, some energy retrofit measures have been implemented. The obtained results allow to discuss two key points for researches in matter of energy refurbishment of buildings: a) the importance of using validated models to simulate the present performance; b) the environmental benefits and the economic implications of a deep energy refurbishment
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