Robust 3D Surface Recovery by Applying a Focus Criterion in White Light Scanning Interference Microscopy

White light scanning interference (WLSI) microscopes provide an accurate surface topography of engineered surfaces. However, the measurement accuracy is substantially reduced in surfaces with low-reflectivity regions or high roughness, like a surface affected by corrosion. An alternative technique called shape from focus (SFF) takes advantage of the surface texture to recover the 3D surface by using a focus metric through a vertical scan. In this work, we propose a technique called SFF-WLSI, which consists of recovering the 3D surface of an object by applying the Tenegrad Variance (TENV) focus metric to WLSI images. Extensive simulation results show that the proposed technique yields accurate measurements under different surface roughness and surface reflectivity, outperforming the conventional WLSI and the SFF techniques. We validated the simulation results on two real objects with a Mirau-type microscope. The first was a flat lapping specimen with Ra = 0.05 {\mu}m for which we measured an average value of Ra = 0.055 {\mu}m and standard deviation {\sigma} = 0.008 {\mu}m. The second was a metallic sphere with corrosion, which we reconstructed with WLSI versus the proposed SFF-WLSI technique, producing a better 3D reconstruction with less undefined depth values.Comment: 2019 Optical Society of America. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited. This work has been partly funded by Colciencias project 538871552485 and Colciencias doctoral support program 785-201

Are quantization rules for horizon areas universal?

Doubts have been expressed on the universality of holographic/string-inspired quantization rules for the horizon areas of stationary black holes or the products of their radii, already in simple 4-dimensional general relativity. Realistic black holes are not stationary but time-dependent. Using two examples of 4D general-relativistic spacetimes containing dynamical black holes for at least part of the time, it is shown that the quantization rules (even counting virtual horizons) cannot hold, except possibly at isolated instants of time, and do not seem to be universal.Comment: One example and one figure added, two figures improved, bibliography expanded and updated. Matches the version accepted for publication in Phys. Rev.

Fire severity is more sensitive to low fuel moisture content on Calluna heathlands than on peat bogs

Moorland habitats dominated by the dwarf shrub Calluna vulgaris provide important ecosystem services. Drought is projected to intensify throughout their range, potentially leading to increased fire severity as moisture is a key control on severity. We studied the effect of low fuel moisture content (FMC) on fire severity by using 2 × 2 m rain-out shelters prior to completing 19 experimental fires in two sites in Scotland (UK): a dry heath with thin organic soils and a raised bog with deep, saturated peat, both dominated by Calluna vulgaris. Reduced FMC of the moss and litter (M/L) layer at both sites, and the soil moisture of the dry heath, increased fire-induced consumption of the M/L layer and soil heating at both sites. Increase in fire severity was greater at the dry heath than at the raised bog, e.g. average maximum temperatures at the soil surface increased from 31 °C to 189 °C at the dry heath, but only from 10 °C to 15 °C at the raised bog. Substantial M/L layer consumption was observed when its FMC was below 150%. This led to larger seasonal and daily soil temperature fluctuation, particularly at the dry heath during warm months. The results suggest that low FMC following predicted changes in climate are likely to increase wildfire severity and that the impact on vegetation composition and carbon stores may be greater at heathlands than at peatlands. Managed burning aiming to minimise fire severity (e.g. ignition of the M/L layer and exposure to lethal temperatures of ericoid seeds) should be carried out when the FMC of the M/L layer is above 150% and the FMC of the soil is above 200–300%

Remarks on the Myers-Perry and Einstein Gauss-Bonnet Rotating Solutions

The Kerr-type solutions of the five-dimensional Einstein and Einstein-Gauss-Bonnet equations look pretty similar when written in Kerr-Schild form. However the Myers-Perry spacetime is circular whereas the rotating solution of the Einstein-Gauss-Bonnet theory is not. We explore some consequences of this difference in particular regarding the (non) existence of Boyer-Lindquist-type coordinates and the extension of the manifold

PAH emission in the proplyd HST10: what is the mechanism behind photoevaporation?

Proplyds are photodissociation region (PDR)-like cometary cocoons around young stars which are thought to originate through photo-evaporation of the central protoplanetary disk by external UV radiation from the nearby OB stars. This letter presents spatially resolved mid-infrared imaging and spectroscopy of the proplyd HST10 obtained with the VLT/VISIR instrument. These observations allow us to detect Polycyclic Aromatic Hydrocarbons (PAH) emission in the proplyd photodissociation region and to study the general properties of PAHs in proplyds for the first time. We find that PAHs in HST10 are mostly neutral and at least 50 times less abundant than typical values found for the diffuse ISM or the nearby Orion Bar. With such a low PAH abundance, photoelectric heating is significantly reduced. If this low abundance pertains also to the original disk material, gas heating rates could be too low to efficiently drive photoevaporation unless other processes can be identified. Alternatively, the model behind the formation of proplyds as evaporating disks may have to be revised.Comment: 5 pages, 3 figures, 1 tabl

Manejo de plantas daninhas na produção de arroz orgânico.

bitstream/item/78976/1/documento-304.pd

Orientações para o uso correto de herbicidas no arroz BRS Sinuelo CL.

bitstream/item/32586/1/Orientacoes.para.uso.correto.de.herbicidas.no.arroz.BRS.Sinuelo.pdfResponsáveis técnicos: Giovani Theisen, André Andres (CPACT)

Diferenças entre espécies de Ervilhaca (Vicia sativa e Vicia villosa) quanto à sensibilidade aos herbicidas utilizados para seu controle em trigo.

bitstream/item/36298/1/comunicado-244.pd