Search results for " white"

Probabilistic response of nonlinear systems via PI: normal, Poissonian and combined white noises

2009

A novel method based on augmented Markov vector process for the time-variant extreme value distribution of stochastic dynamical systems enforced by P…

2020

Abstract The probability density function (PDF) of the time-variant extreme value process for structural responses is of great importance. Poisson white noise excitation occurs widely in practical engineering problems. The extreme value distribution of the response of systems excited by Poisson white noise processes is still not yet readily available. For this purpose, in the present paper, a novel method based on the augmented Markov vector process for the PDF of the time-variant extreme value process for a Poisson white noise driven dynamical system is proposed. Specifically, the augmented Markov vector (AMV) process is constructed by combining the extreme value process and its underlying…

Stability improvement of PMMA and Lumogen® coatings for hybrid white LEDs

2014

Hybrid white LEDs employing perylene-based dyes for the frequency down-conversion of blue light, generated by a standard inorganic source, suffer from colour rendering variations due to the degradation of the organic molecule under prolonged irradiation. To avoid such inconvenient, proper encapsulation of the dyes in resins or other polymer matrices can prevent their accelerated ageing; nevertheless, embedding polymers can also exhibit significant bleaching caused by chemico-physical agents. Among all, polymethyl methacrilate (PMMA) is one of the most used materials for the fabrication of hybrid LEDs' colour conversion coatings, therefore its stability needs to be investigated.

Fourier Transform Infrared (FT-IR) Microspectroscopy of 20th Century Russian Oil Paintings: Problem of Dating

2015

Analysis of the IR spectra of samples from 230 Russian oil paintings of the 20th century is used to propose a procedure for the threshold estimation of the age of paintings based on measured parameters (intensity ratios of spectral bands). The bands of compounds that are formed upon interaction of pigment (zinc white) with oil are used for dating.

Joaquin Sorolla's pigment characterisation of the paintings ‘Vision of Spain’ by means of EDXRF portable system

2011

In this work, portable energy dispersive X-ray fluorescence (EDXRF) spectrometry was employed to the characterisation of the palette used by the Spanish artist Joaquin Sorolla (1863–1923) in the paintings ‘Vision of Spain’, a set of 14 oils on canvas painted by Sorolla between 1911 and 1919 by order of Mr Archer Huntington to decorate the library of the Hispanic Society of America (HSA) in New York. The analyses, sponsored by BANCAJA and provided by the HSA, were carried out in situ, prior to the cleaning and restoration process, while the paintings hanging on the walls of the library of the HSA. The results revealed that the paintings were made over different priming layers containing, res…

Palermo bianca

2019

Palermo bianca potrebbe sembrare una città invisibile; e, tuttavia, nonostante le stratificazioni e le trasformazioni, è da annoverare tra le autentiche città bianche, specialmente per essere una delle capitali del Mediterraneo. Il bianco è rintracciabile in alcune tappe della storia della città, confermando le ambigue origini ed i molteplici significati di questo colore. White Palermo may seem like an invisible city; and, however, despite the stratifications and transformations, it is to be counted among the authentic white cities, especially for being one of the capitals of the Mediterranean. White is traceable in some stages of the city's history, confirming the ambiguous origins and mul…

Non-linear systems under Levy White Noise Handled by path integration method

2009

Aim of this paper is an investigation on the consistency of the Path Integration (PI) method already proposed by Naess & Johansen, 1991,1993 for non-linear systems driven by α-stable white noise. It is shown that in the limit, as τ→0, the Einstein-Smoluchowsky (ES) equation is fully restored. Once the consistency of the PI is demonstrated for the half oscillator, then the extension of the ES equation for MDOF system is found starting from the PI method.

Cerebral White Matter Lesions and Dysmorphisms: Signs Suggestive of 6p25 Deletion Syndrome—Literature Review

2019

AbstractDeletion of the region including chromosome 6p25 has been defined as a syndrome, with more than 68 reported cases. Individuals affected by the syndrome exhibit variable findings, including developmental delay and intellectual disability, cardiac anomalies, dysmorphic features, and—less commonly—skeletal and renal malformations. Ocular and hearing abnormalities are the most notable presenting features. The region encompasses more than 15 genes, of which the FOX group is the most likely causal factor of the clinical manifestations. We report the case of a 2-year-old child with developmental delay, generalized hypotonia, facial dysmorphism, and anomalies involving malformations of the …

A simplified method to quantitate atherosclerosis in the rabbit aorta.

2001

A simple method to quantitatively evaluate atherosclerosis in the rabbit aorta by measuring macroscopic lesion areas (%) was attempted in the present study. Ten female New Zealand white rabbits were fed on a cholesterol-rich diet (5/1000 g of food) during 4 months. Five of them were oophorectomized at the beginning and all were sacrificed at the end. Total levels of cholesterol increased from 50.7+/-14.7 mg/dl to 782.8+/-296.0. No significant differences were observed between oophorectomized and intact rabbits. At 4 months, the cholesterol-rich diet caused in both, intact and oophorectomized rabbits, atherosclerotic lesions affecting 17 and 46% of the aortic surface, respectively. This meth…

Detection and Discrimination of Inter-Turn Short Circuit and Demagnetization Faults in PMSMs Based on Structural Analysis

2021

This paper presents a fault diagnosis method based on structural analysis of permanent magnet synchronous motors (PMSMs), focusing on detecting and discriminating two of the most common faults in PMSMs, namely demagnetization and inter-turn short circuit faults. The structural analysis technique uses the dynamic mathematical model of the PMSM in matrix form to evaluate the system’s structural model. After obtaining the analytical redundancy using the over-determined part of the system, it is divided into redundant testable sub-models. Four structured residuals are designed to detect and isolate the investigated faults, which are applied to the system in different time intervals. Finally, th…