Search results for "SPECTRA"

Pion-induced η production on nuclei

1990

Abstract Low-energy η production on nuclei is investigated in a DWIA framework, using a Green function method. The η potential is constructed by folding medium-modified η N → S 11 → η N scattering amplitudes with nuclear wave functions. A phenomenological spreading potential is introduced for the intermediate S 11 resonance. Calculated ( π + , p ) η cross sections on 12 C and 16 O with the spreading potential having an imaginary part of the order of −50 ∼ −100 MeV compare favorably with recent experimental data. It is also shown that the energy dependence of the ( π + , η ) inclusive spectra is nicely reproduced, though the magnitude is somewhat underestimated.

A geometric street scattering channel model for car-to-car communication systems

2011

This paper presents a geometric street scattering channel model for car-to-car (C2C) communication systems under line-of-sight (LOS) and non-LOS (NLOS) propagation conditions. Starting from the geometric model, we develop a stochastic reference channel model, where the scatterers are uniformly distributed in rectangles in the form of stripes parallel to both sides of the street. We derive analytical expressions for the probability density functions (PDFs) of the angle-of-departure (AOD) and the angle-of-arrival (AOA). We also investigate the Doppler power spectral density (PSD) and the autocorrelation function (ACF) of the proposed model, assuming that the mobile transmitter (MT) and the mo…

Polarization of τ in quasielastic (anti)neutrino scattering: The role of spectral functions

2019

We present a study of the $\tau$ polarization in charged-current quasielastic (anti)neutrino-nucleus scattering. The spectral function formalism is used to compute the differential cross section and the polarization components for several kinematical setups, relevant for neutrino-oscillation experiments. The effects of the nuclear corrections in these observables are investigated by comparing the results obtained using two different realistic spectral functions, with those deduced from the relativistic global Fermi gas model, where only statistical correlations are accounted for. We show that the spectral functions, although they play an important role when predicting the differential cross…

Working group on hadron polarizabilities and form factors

1998

Raman study of crystals

1997

In this work we present a polarized Raman study of single crystals for several values of the concentration made using different scattering geometries. The Raman spectra, composed of broad bands, have been fitted in accordance with a symmetry analysis which allowed us to assign the vibrational modes, and determine their frequencies and damping constants. The results are compatible with an average hexagonal symmetry for the solid solutions with x in the range . In each of the spectra we found two bands at about 590 and , probably associated with the existence of structures in the solid solutions.

UAV Communication Strategies in the Next Generation of Mobile Networks

2020

| openaire: EC/H2020/857031/EU//5G!Drones The Next Generation of Mobile Networks (NGMN) alliance advocates the use of different means to support vehicular communications. This aims to cope with the massive data generated by these devices which could affect the Quality of Service (QoS) of the associated applications, but also the overall operation carried out by the vehicles. However, efficient communication strategies must be considered in order to select, for each vehicle, the communication mean ensuring the best QoS. In this paper, we tackle this issue and we propose efficient communication strategies for Unmanned Aerial Vehicles (UAVs). In addition to direct UAV-to-Infrastructure communi…

Global sensitivity analysis of the A-SCOPE model in support of future FLEX fluorescence retrievals

2014

In support of ESA's Earth Explorer 8 candidate mission FLEX (FLuorescence EXplorer), a Photosynthesis Study has been initiated to quantitatively link fluorescence to photosynthesis. This led to the development of A-SCOPE, a graphical user interface software package that integrates multiple biochemical models into the soil-vegetation-atmosphere-transfer model SCOPE. Its latest version (v1.53) has been successfully verified and was subsequently evaluated through a global sensitivity analysis. By using the method of Saltelli [4], the relative importance of each input variable to model outputs was quantified through first order and total effect sensitivity indices. Variations in leaf area index…

Determination of sea surface temperature using combined TOVS and AVHRR data. Application to the Canary Islands area, Spain

1996

Abstract The determination of sea surface temperature from satellite is performed by means of multi-channel algorithms with channels 4 and 5 of AVHRRNOAA or using radiative transfer models and radiosounding profiles of air temperature and humidity. In this work, an alternative to the current algorithms has been established. A new method combining the information supplied by sensors of TOVS and AVHRR systems onboard NOAA satellites is proposed. It is based on the split-window technique, the coefficients A and B being determined as a function of the water vapour content, which is calculated using the TOVS sensors. The T4 and T5 temperatures are supplied by the AVHRR system. Then, combining bo…

Quantitative Multispectral Imaging Differentiates Melanoma from Seborrheic Keratosis.

2021

Melanoma is a melanocytic tumor that is responsible for the most skin cancer-related deaths. By contrast, seborrheic keratosis (SK) is a very common benign lesion with a clinical picture that may resemble melanoma. We used a multispectral imaging device to distinguish these two entities, with the use of autofluorescence imaging with 405 nm and diffuse reflectance imaging with 525 and 660 narrow-band LED illumination. We analyzed intensity descriptors of the acquired images. These included ratios of intensity values of different channels, standard deviation and minimum/maximum values of intensity of the lesions. The pattern of the lesions was also assessed with the use of particle analysis. …

Skin cancer screening – better safe than sorry

2020

Skin cancer is the most common type of cancers. In Latvia, on average there are approximately 200 new melanoma and 1300 non-melanoma cancer cases per year. Non-melanoma cancers are: Basal Cell Carcinoma, Squamous Cell Carcinoma and others. It is essential to discover skin cancer at an early stage when it is treatable. For this reason, a reliable, non-invasive and quantitative skin cancer screening method is necessary in order to discover skin cancer as early as possible and to help physicians such as general practitioners and dermatologists assign patients to the best treatment as soon as possible. In this article, the current skin cancer incidence as well as the screening situation in Latv…