Search results for "RAYS"
showing 10 items of 1136 documents
Image Colorization Method Using Texture Descriptors and ISLIC Segmentation
2017
We present a new colorization method to assign color to a grayscale image based on a reference color image using texture descriptors and Improved Simple Linear Iterative Clustering (ISLIC). Firstly, the pixels of images are classified using Support Vector Machine (SVM) according to texture descriptors, mean luminance, entropy, homogeneity, correlation, and local binary pattern (LBP) features. Then, the grayscale image and the color image are segmented into superpixels, which are obtained by ISLIC to produce more uniform and regularly shaped superpixels than those obtained by SLIC, and the classified images are further post-processed combined with superpixles for removing erroneous classific…
Detection of events by means of plane wave decomposition analysis and cross-correlation technniques using a circular array of microphones
2013
[EN] This article deals with the study and analysis of room acoustics through a process of sound field decomposition sampled with microphones circular arrays. The spatial characteristics of the sound field inside a room can be meaningfully described by means of microphone array processing techniques. In this context, the set of impulse responses sampled by a microphone array can be seen as an image made of acoustic planewave footprints. Due to the circular geometry of the microphone array, these footprints have a cosine-like shape that can be fully described as a function of the direction of arrival (DOA) of the impinging plane wave.Plane-wave decomposition (PWD) technique using microphone …
INTEGRAL/SPI ground calibration
2003
Three calibration campaigns of the spectrometer SPI have been performed before launch in order to determine the instrument characteristics, such as the effective detection area, the spectral resolution and the angular resolution. Absolute determination of the effective area has been obtained from simulations and measurements. At 1 MeV, the effective area is 65 cm^2 for a point source on the optical axis, the spectral resolution ~2.3 keV. The angular resolution is better than 2.5 deg and the source separation capability about 1 deg. Some temperature dependant parameters will require permanent in-flight calibration.
Observation of the cosmic ray moon shadowing effect with the ARGO-YBJ experiment
2011
Cosmic rays are hampered by the Moon and a deficit in its direction is expected (the so-called Moon shadow). The Moon shadow is an important tool to determine the performance of an air shower array. Indeed, the westward displacement of the shadow center, due to the bending effect of the geomagnetic field on the propagation of cosmic rays, allows the setting of the absolute rigidity scale of the primary particles inducing the showers recorded by the detector. In addition, the shape of the shadow permits to determine the detector point spread function, while the position of the deficit at high energies allows the evaluation of its absolute pointing accuracy. In this paper we present the obser…
BIOADHESIVE PROPERTIES OF A POLYAMINOACIDIC HYDROGEL: EVALUATION BY ATR FT-IR SPECTROSCOPY
2005
The bioadhesive properties of a novel chemical hydrogel based on a polymer of protein-like structure, have been investigated by using ATR FT-IR spectroscopy. In particular, the copolymer PHG obtained by partial derivatization of PHEA with GMA was chemically crosslinked by UV irradiation at 313 nm. Crosslinked PHG was treated with water to obtain a swelled sample, named PHG-UV gel, that was brought into contact with a phosphate buffer/citric acid solution at pH 7.0 in the absence or in the presence of mucin at various concentrations (0.01, 0.1 and 1 wt.-%). Preliminary dynamic swelling studies have evidenced the occurrence of an interaction between the PHG-UV gel and the glycoprotein. This r…
UV-photocrosslinking of inulin derivatives to produce hydrogels for drug delivery application.
2005
In this work, INU, a natural polysaccharide, has been chemically modified in order to obtain new photocrosslinkable derivatives. To reach this goal, INU has been derivatized with MA thus obtaining four samples (INU-MA derivatives) as a function of the temperature and time of reaction. An aqueous solution of the derivative INU-MA1 was irradiated by using a UV lamp with an emission range from 250 to 364 nm and without using photoinitiators. The obtained hydrogel showed a remarkable water affinity but it underwent a partial degradation in simulated gastric fluid. To overcome this drawback, INU-MA 1 was derivatized with SA thus obtaining the INU-MA1-SA derivative designed to produce a hydrogel …
CONTROLLED RELEASE OF IgG BY NOVEL UV INDUCED POLYSACCHARIDE/POLY(AMINO ACID)HYDROGELS
2009
The development of new protein and peptide drugs needs new delivery systems able to entrap such drugs in safe conditions without affecting their structure and biological activity. In this context, the present work reports a new approach to load IgG, used as a model of therapeutic proteins such as anti-TNF-alpha monoclonal antibodies, into a polymeric system able to release the entrapped IgG in a controlled manner. In particular, new polysaccharide/poly(amino acid) UV induced hydrogels are proposed as colon delivery systems for human IgG. The poly(amino acid), alpha,beta-poly[N-(2-hydroxyethyl)-D,L-aspartamide], has been functionalized with methacrylic anhydride, while the polysaccharide, in…
Control of dataset bias in combined Affymetrix cohorts of triple negative breast cancer
2014
AbstractHeterogenous subtypes of breast cancer need to be analyzed separately. Pooling of datasets can provide reasonable sample sizes but dataset bias is an important concern. We assembled a combined dataset of 579 Affymetrix microarrays from triple negative breast cancer (TNBC) in Gene Expression Omnibus (GEO) series GSE31519. We developed a method for selecting comparable datasets and to control for the amount of dataset bias of individual probesets.
Thermal and non-thermal preservation techniques of tiger nuts' beverage "horchata de chufa". Implications for food safety, nutritional and quality pr…
2017
"Horchata de chufa" is a traditional Spanish beverage produced from tiger nuts (Cyperus esculentus L.). Due to its richness in nutritional compounds, it is highly perishable and its conservation by pasteurization and/or adding preservatives is required. Although efficient, conventional thermal treatment for pasteurization induces changes in the nutritional and sensory properties. Replacing conventional pasteurization by non-thermal technologies such as pulsed electric fields, ultraviolet, and high pressure, combined with moderate temperatures (<40°C) allows a reduction of energy consumption, along with the preservation of the most thermo-sensitive molecules. Accordingly, this review deals w…
Data-driven estimation of the invisible energy of cosmic ray showers with the Pierre Auger Observatory
2019
The determination of the primary energy of extensive air showers using the fluorescence detection technique requires an estimation of the energy carried away by particles that do not deposit all their energy in the atmosphere. This estimation is typically made using Monte Carlo simulations and thus depends on the assumed primary particle mass and on model predictions for neutrino and muon production. In this work we present a new method to obtain the invisible energy from events detected by the Pierre Auger Observatory. The method uses measurements of the muon number at ground level, and it allows us to significantly reduce the systematic uncertainties related to the mass composition and th…