Search results for "defect"

Visual defects in subjects with Down’s syndrome

1995

Because the incidence of other visual defects is much higher in cases of Down’s syndrome than in individuals with other forms of retardation (Gardiner, 1967; Aitchison et al., 1990), we tested the color vision of a population of Down’s syndrome patients, using Ishihara plates and the Davico anomaloscope. The Down’s syndrome group had a significantly higher proportion of color deficiencies than either normal controls or a matched mentally retarded population. Refractive errors were corrected with static retinoscopy, and spatial contrast sensitivity was measured with the Vistech test.

Deep traps in InGaN/GaN single quantum well structures grown with and without InGaN underlayers

2020

The electrical properties and deep trap spectra were compared for near-UV GaN/InGaN quantum well (QW) structures grown on free-standing GaN substrates. The structures differed by the presence or absence of a thin (110 nm) InGaN layer inserted between the high temperature GaN buffer and the QW region. Capacitance-voltage profiling with monochromatic illumination showed that in the InGaN underlayer (UL), the density of deep traps with optical threshold near 1.5 eV was much higher than in the QW and higher than for structures without InGaN. Irradiation with 5 MeV electrons strongly increased the concentration of these 1.5 eV traps in the QWs, with the increase more pronounced for samples witho…

The role of evanescent modes in Global-Local analysis of UGW in plates with varying local zone-scatterer relations

2023

In order to provide a reliable and robust SHM performance, Ultrasonic Guided Waves (UGWs) need to be analyzed and understood. Numerical modeling of UGW propagation and scattering by hybrid methods offers the possibility of simulating UGW interaction with waveguides of arbitrary cross-sections and discontinuities. Maximizing the accuracy of such methods is important to perform quantitative SHM, while maintaining minimum computational cost. This work investigates the role of evanescent modes in the numerical analysis of UGWs in aluminum and composite plates with defects, by the hybrid Global-Local method. The complex solutions to the UGW eigenvalue problem are found and the scattering spectra…

Implicaciones evolutivas de la transmisión colectiva de virus

2022

Es habitual asumir en virología que las partículas virales dispersan de forma libre e independiente durante su transmisión entre células, tejidos, órganos y hospedadores. Sin embargo, esta visión ha sido cuestionada recientemente por la caracterización de múltiples estrategias que los virus emplean para transmitirse colectivamente. Entre ellas se encuentran las llamadas unidades infecciosas colectivas, que incluyen agregados virales, viriones poliploides, vesículas extracelulares o estructuras específicas como los cuerpos de oclusión; pero también diversos modos de transmisión directa y masiva de viriones entre células. En principio, la agrupación de la progenie viral disminuye el número de…

Photoluminescence of SiO2 under excitation by synchrotron radiation above the fundamental absorption edge

2008

Use of electronic nose to determine defect percentage in oils. Comparison with sensory panel results

2010

Abstract An electronic nose based on an array of 6 metal oxide semiconductor sensors was used, jointly with linear discriminant analysis (LDA) and artificial neural network (ANN) method, to classify oils containing the five typical virgin olive oil (VOO) sensory defects (fusty, mouldy, muddy, rancid and winey). For this purpose, these defects, available as single standards of the International Olive Council, were added to refined sunflower oil. According to the LDA models and the ANN method, the defected samples were correctly classified. On the other hand, the electronic nose data was used to predict the defect percentage added to sunflower oil using multiple linear regression models. All …

SIRM–SIC appropriateness criteria for the use of Cardiac Computed Tomography. Part 1: Congenital heart diseases, primary prevention, risk assessment …

2021

AbstractIn the past 20 years, Cardiac Computed Tomography (CCT) has become a pivotal technique for the noninvasive diagnostic work-up of coronary and cardiac diseases. Continuous technical and methodological improvements, combined with fast growing scientific evidence, have progressively expanded the clinical role of CCT. Recent large multicenter randomized clinical trials documented the high prognostic value of CCT and its capability to increase the cost-effectiveness of the management of patients with suspected CAD. In the meantime, CCT, initially perceived as a simple non-invasive technique for studying coronary anatomy, has transformed into a multiparametric “one-stop-shop” approach abl…

The Social Life of Viruses

2021

Despite their simplicity, viruses exhibit certain types of social interactions. Situations in which a given virus achieves higher fitness in combination with other members of the viral population have been described at the level of transmission, replication, suppression of host immune responses, and host killing, enabling the evolution of viral cooperation. Although cellular coinfection with multiple viral particles is the typical playground for these interactions, cooperation between viruses infecting different cells is also established through cellular and viral-encoded communication systems. In general, the stability of cooperation is compromised by cheater genotypes, as best exemplified…

Positron Studies of Subsurface Zone in Titanium Created in Sliding Wear

2014

Positron annihilation studies of the subsurface zone constituted during dry sliding in pure titanium are reported. A new type of defect depth profile in this zone, which is not an exponential decay usually reported for other metals and alloys, is observed. Two layers in the subsurface zone are present in this metal. In the layer adjacent to the worn surface, the characteristic plateau of the mean positron lifetime that extends to a depth of 60–70 μm was observed. Small vacancy clusters and dislocations were recognized in this layer. At deeper zone, the mean positron lifetime decreased exponentially in the manner typical for the other metals. In this zone, vacancy clusters increase in size a…

Revista de logopedia, foniatría y audiología

2013

Resumen El objetivo del presente estudio fue averiguar si la informacion que proporcionan las pruebas ABX y AX sobre la percepcion de sonidos del habla en una muestra de ninos con trastornos del habla es la misma o no. Participaron 86 ninos de edades comprendidas entre los 3 anos y 2 meses y los 5 anos y 11 meses, siendo la media de 4 anos y 7 meses. Fueron seleccionados de entre una muestra de 1.283 ninos procedentes de 11 colegios diferentes de la Comunitat Valenciana cuya lengua materna era el espanol. En primer lugar se evaluo la produccion del habla. En funcion de los errores cometidos por cada nino, se construyeron y aplicaron las pruebas ABX y AX, utilizando los criterios de Locke pa…