Search results for "PTH"

Contrail ice particles in aircraft wakes and their climatic importance

2013

[1] Measurements of gaseous (NO, NOy, SO2, HONO) and ice particle concentrations in young contrails in primary and secondary wakes of aircraft of different sizes (B737, A319, A340, A380) are used to investigate ice particle formation behind aircraft. The gas concentrations are largest in the primary wake and decrease with increasing altitude in the secondary wake, as expected for passive trace gases and aircraft-dependent dilution. In contrast, the measured ice particle concentrations were found larger in the secondary wake than in the primary wake. The contrails contain more ice particles than expected for previous black carbon (soot) estimates. The ice concentrations may result from soot-…

Statistical atmospheric parameter retrieval largely benefits from spatial-spectral image compression

2021

The infrared atmospheric sounding interferometer (IASI) is flying on board of the Metop satellite series, which is part of the EUMETSAT Polar System. Products obtained from IASI data represent a significant improvement in the accuracy and quality of the measurements used for meteorological models. Notably, the IASI collects rich spectral information to derive temperature and moisture profiles, among other relevant trace gases, essential for atmospheric forecasts and for the understanding of weather. Here, we investigate the impact of near-lossless and lossy compression on IASI L1C data when statistical retrieval algorithms are later applied. We search for those compression ratios that yield…

Large Depth-of-Field Integral Microscopy by Use of a Liquid Lens

2018

Integral microscopy is a 3D imaging technique that permits the recording of spatial and angular information of microscopic samples. From this information it is possible to calculate a collection of orthographic views with full parallax and to refocus computationally, at will, through the 3D specimen. An important drawback of integral microscopy, especially when dealing with thick samples, is the limited depth of field (DOF) of the perspective views. This imposes a significant limitation on the depth range of computationally refocused images. To overcome this problem, we propose here a new method that is based on the insertion, at the pupil plane of the microscope objective, of an electrical…

Fourier-domain lightfield microscopy: a new paradigm in 3D microscopy

2020

Recently, integral (also known as lightfield or plenoptic) imaging concept has been applied successfully to microscopy. The main advantage of lightfield microscopy when compared with conventional 3D imaging techniques is that it offers the possibility of capturing the 3D information of the sample after a single shot. However, integral microscopy is now facing many challenges, like improving the resolution and depth of field of the reconstructed specimens or the development and optimization of specially-adapted reconstruction algorithms. This contribution is devoted to review a new paradigm in lightfield microscopy, namely, the Fourier-domain integral microscope (FiMic), that improves the ca…

Robust Depth Estimation for Light Field Microscopy

2019

Light field technologies have seen a rise in recent years and microscopy is a field where such technology has had a deep impact. The possibility to provide spatial and angular information at the same time and in a single shot brings several advantages and allows for new applications. A common goal in these applications is the calculation of a depth map to reconstruct the three-dimensional geometry of the scene. Many approaches are applicable, but most of them cannot achieve high accuracy because of the nature of such images: biological samples are usually poor in features and do not exhibit sharp colors like natural scene. Due to such conditions, standard approaches result in noisy depth ma…

Spatial distribution of various types of bulbar respiratory neurons in the rabbit

1977

In anesthetized rabbits, the burst activity of 277 single respiratory neurons was recorded extracellularly. The neurons were classified according to their spike incidence distribution within the respiratory cycle and to their response to lung distension or collapse (alpha or beta type). About one third of the neurons found in all animals were located at the level of the caudal end of the promontorium gliosum, widely scattered over the bulbar cross-section. More rostrally the units were located within a dorsal area neighbouring the tractus solitarius, more caudally within a ventral field surrounding the nucleus ambiguus. Most of the inspiratory neurons (the most frequently encountered type) …

Turbulence and financial markets

1996

Les langues, facteurs du rendement en lecture dans les évaluations PIRLS

2011

The starting point of this research is the question, may reading acquisition be more or less effective depending on the language in which it is perform? Two categories for classifying the languages have been developed. First the notion of linguistic family is employed to describe the languages from a cultural and historical perspective. Secondly, the notion of orthographic depth is used for differentiating the languages according to the correspondence between orthography and phonetic. These categories have been related to the databases PIRLS 2001 and 2006 (international assessments about reading developed by the IEA), the aim being to connect reading achievement to the language in which stu…

Neutron–gamma mixed field measurements by means of MCP–TLD600 dosimeter pair

2007

Abstract In this paper, we compared the TL response of three types of thermoluminescence dosimeters, TLD600 (6LiF:Mg,Ti), TLD700 (7LiF:Mg,Ti) and MCP (LiF:Mg,Cu,P) after exposure to a n–γ mixed field in the fluence range of radiotherapeutic applications. Since a dosimeter pair is required to discriminate the two components of the mixed field, we analyzed the ability of each dosimeter pair to provide the fluence value in the mixed field. At this aim we performed a 60Co–γ calibration and a neutron calibration for all three dosimeter types. Finally, a blind test was performed in order to analyze the accuracy of each dosimeter pair and we found that in this mixed field the fluence value obtaine…

Comparison of LIBS results on ITER-relevant samples obtained by nanosecond and picosecond lasers

2019

This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement number 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. Work performed under EUROfusion WP PFC.