Performance of a Differential GPS in Dynamic Mode Under Sitka Spruce Canopies

Quantified, performance indicators for dynamic mode Differential GPS (DGPS) were collected at 31 sites established under 3 canopy classes (none, pre-first thinning and mature) of Sitka spruce stands in Ireland with varying altitude (100-500 m) and aspect. Canopy cover was quantified using total obstruction, size of largest opening and fragmentation of sky view. At sites with no canopy above 2 m, a mean precision of 1.5 m was recorded. Where canopy was present, precision ranged between 2.6 m and 2.8 m. The results indicated that in dynamic mode, differences in DGPS performance between canopy cover types were limited to a presence/absence effect. oss of 3-dimensional operation (i.e. only 3 satellites in view) occurred more frequently than loss of differential correction signal and thus had a greater impact on recorded precision over the duration of the experiment. It was concluded from the data collected that the most versatile approach when using dynamic DGPS is to collect more (potentially poorer quality) data, rather than to apply a filter at the signal acquisition stage. The observations made, and the conclusions drawn in this paper are relevant to the forest industry in the selection and operation of DGPS equipment for dynamic tasks where ~ 2 m precision is required

Un pasaje de la historia del Colegio de las Vírgenes de Zaragoza: la construcción de su nueva iglesia y la reforma del retablo mayor. 1607-1610, 1631

La construcción de la iglesia del Colegio de las Vírgenes de Zaragoza entre 1607 y 1610, a cargo de Gaspar de Villaverde y Francisco Aguinaga, forma parte del proceso de introducción del nuevo lenguaje arquitectónico clasicista en la capital aragonesa. La localización del contrato firmado con estos dos maestros para su edificación, unido a diversos materiales gráficos y fotográficos, ayuda a conocer cómo era este edificio ya desaparecido. También se aportan nuevos datos sobre el mecenazgo que el arzobispo Tomás de Borja ejerció sobre este edificio y la dotación de su capilla mayor, que el prelado eligió como lugar de enterramiento. The construction of the Colegio de las Vírgenes church in Zaragoza took place between 1607 and 1610. It was directed by Gaspar de Villaverde and Francis-co Aguinaga and is part of the process of introducing the new classicist architectural language in the Aragonese capital. The location of the contract signed with the two aforementioned masters for its construction, together with various graphic and pho-tographic materials, helps us to know what this currently disappeared building was like. New information is also provided on the patronage that Archbishop Tomás de Borja exercised over this building and the endowment of its main chapel, which the prelate chose as a burial place

Photoluminescence study of excitons in homoepitaxial GaN

High-resolution photoluminescence spectra have been measured in high-quality homoepitaxial GaN grown on a free-standing GaN substrate with lower residual strain than in previous work. Unusually strong and well-resolved excitonic lines were observed. Based on free- and bound exciton transitions some important GaN parameters are derived. The Arrhenius plot of the free A exciton recombination yields a binding energy of 24.7 meV. Based on this datum, an accurate value for the band-gap energy, EG(4.3 K) = 3.506 eV, can be given. From the donor bound excitons and their “two-electron” satellites, the exciton localization energy and donor ionization energy are deduced. Finally, estimates of the electron and hole masses have been obtained within the effective mass [email protected] ; [email protected]

Optical characterization of Mg-doped GaN films grown by metalorganic chemical vapor phase deposition

Scanning electron microscopy, micro-Raman, and photoluminescence (PL) measurements are reported for Mg-doped GaN films grown on (0001) sapphire substrates by low-pressure metalorganic chemical vapor phase deposition. The surface morphology, structural, and optical properties of GaN samples with Mg concentrations ranging from 1019 to 1021 cm−3 have been studied. In the scanning micrographs large triangular pyramids are observed, probably due to stacking fault formation and three-dimensional growth. The density and size of these structures increase with the amount of magnesium incorporated in the samples. In the photoluminescence spectra, intense lines were found at 3.36 and 3.31 eV on the triangular regions, where the presence of cubic inclusions was confirmed by micro-Raman measurements. The excitation dependence and temperature behavior of these lines enable us to identify their excitonic nature. From our study we conclude that the interface region between these defects and the surrounding wurtzite GaN could be responsible for PL [email protected] ; [email protected] ; [email protected]

Collagen-induced arthritis in C57BL/6 mice is associated with a robust and sustained T-cell response to type II collagen

Many genetically modified mouse strains are now available on a C57BL/6 (H-2b) background, a strain that is relatively resistant to collagen-induced arthritis. To facilitate the molecular understanding of autoimmune arthritis, we characterised the induction of arthritis in C57BL/6 mice and then validated the disease as a relevant pre-clinical model for rheumatoid arthritis

Residual strain effects on the two-dimensional electron gas concentration of AlGaN/GaN heterostructures

Ga-face AlGaN/GaN heterostructures with different sheet carrier concentrations have been studied by photoluminescence and Raman spectroscopy. Compared to bulk GaN, an energy shift of the excitonic emission lines towards higher energies was observed, indicating the presence of residual compressive strain in the GaN layer. This strain was confirmed by the shift of the E2 Raman line, from which biaxial compressive stresses ranging between 0.34 and 1.7 GPa were deduced. The spontaneous and piezoelectric polarizations for each layer of the heterostructures have been also calculated. The analysis of these quantities clarified the influence of the residual stress on the sheet electron concentration (ns). Possible causes for the discrepancies between the calculated and experimentally determined sheet carrier densities are briefly [email protected] ; [email protected]

Novel Fluorescent Labeled Octasilsesquioxanes Nanohybrids as Potential Materials for Latent Fingerprinting Detection

The recent demand for fluorescent labeled materials (FLMs) in forensic security concepts such as latent fingerprints (LFs) that encodes information for anti-counterfeiting and encryption of confidential data makes necessary the development of building new and innovative materials. Here, novel FLMs based on Polyhedral Oligomeric Silsesquioxanes (POSS) functionalized with fluorophores via “click” reactions have been successfully synthesized and fully characterized. A comprehensive study of their photophysical properties has displayed large Stokes’s shift together with good photostability in all cases, fulfilling the fundamental requisites for any legible LF detection on various surfaces. The excellent performance of the hetero-bifunctional FLM in the visualization of LF is emphasized by their legibility, selectivity, sensitivity and temporal photostability. In this study, development mechanisms have been proposed and the overall concept constitute a novel approach for vis-à-vis forensic investigations to trace an individual’s identity.Alexander von Humboldt FoundationGeneralitat ValencianaUniversität RegensburgUniversidad de La LagunaMinisterio de Ciencia, Innovación y Universidade

Highly efficient latent fingerprint detection by eight-dansyl-functionalized octasilsesquioxane nanohybrids

The largely demand in continued security issues makes necessary the development of novel materials with outstanding properties to improve the current detection techniques. In this context, latent fingerprint (LF) by fluorescent labeled materials (FLM) is one of the most attractive personnel identification methodologies. Here, two FLM based on polyhedral oligomeric silsesquioxane (POSS) nanohybrids labeled with dansyl chromophores have been synthesized and fully characterized. Their photophysical properties have confirmed that these materials clearly possess the prime qualifications as suitable LF sensing platforms. In fact, they adequately detect LFs on glassy surface with excellence legibility.Alexander von Humboldt FoundationGeneralitat ValencianaUniversit¨at RegensburgMinisterio de Ciencia, Innovación y Universidade