Search results for "SAF"

Experimental determination of the kurtosis of RF noise in microwave low-noise devices

2000

Abstract The degree of the Gaussian nature of the white noise present in microwave low-noise devices is experimentally investigated. The chosen experimental technique consists of simultaneously digitizing four versions of the noise which are amplified by four parallel independent amplifiers. The four independent signals are then used to compute the second, and, to a good approximation, the fourth moment of the noise. The ratio of the fourth moment to the square of the second moment is the kurtosis of the noise. Gaussian processes are characterized by a kurtosis equal to 3. A deviation from this value gives an indication about the degree of non-Gaussian nature of the noise. By using this tec…

Skewness and kurtosis of 1/f noise in semiconductor devices

2000

An experimental investigation of the third and fourth moments of the 1/f noise of two different electronic devices is reported. The skewness and the kurtosis of the noise voltage data are estimated. Although the devices under investigation have similar noise power spectral density, the time waveforms are shown to have slightly different statistical properties. In both cases, a small deviation from Gaussian distribution is observed.

Path Integral Methods for the Probabilistic Analysis of Nonlinear Systems Under a White-Noise Process

2020

Abstract In this paper, the widely known path integral method, derived from the application of the Chapman–Kolmogorov equation, is described in details and discussed with reference to the main results available in literature in several decades of contributions. The most simple application of the method is related to the solution of Fokker–Planck type equations. In this paper, the solution in the presence of normal, α-stable, and Poissonian white noises is first discussed. Then, application to barrier problems, such as first passage problems and vibroimpact problems is described. Further, the extension of the path integral method to problems involving multi-degrees-of-freedom systems is anal…

P26 Early motherhood: a qualitative study exploring experiences of adolescent mothers in the hohoe municipality of ghana

2018

Background Each year between 14 and 15 million adolescent girls give birth, accounting for more than 10% of births globally. Motherhood is an exciting time for every woman and the society at large and also seen as a significant part of any woman’s identity but that is often not the case for the adolescent mother. Adolescent motherhood can be a time of mixed feelings as it occurs at a critical time of their lives. This study examined challenges adolescent mothers face during early motherhood and strategies to improve early motherhood for better social and health outcomes. Methods Based on a phenomenological perspective, this qualitative study was conducted in the Hohoe Municipality where pur…

Seismic prevention and rehabilitation of nonstructural elements. Application experiences of nonstructural pre-seismic evaluation

2012

Topics concerning nonstructural seismic prevention and rehabilitation take their place in the main context of buildings safety in order to explore some aspects of performance of those technical elements. They have become very topical in Italy in the last decade since the repetition of seismic events has made vulnerability and its implications obvious not only in terms of safety risk. This paper reports briefly about author research experiences in this topic and more detail an experience as a component of research team, organizer and tutor in the activities of an international cooperation project between University of Palermo and University of California-Berkeley. After a short introduction …

Promoting health in everyday settings: Opportunities and challenges

2014

Compatibility, effectiveness and susceptibility to degradation of alkoxysilane-based consolidation treatments on a carbonate stone

2021

Abstract Alkoxysilane-based consolidation treatment are commonly employed in restoration and conservation works of Cultural Heritage buildings. However, their poor affinity to carbonate stones is well-known. In this paper, we evaluate three consolidant treatments (two of them modified to incorporate hydrophobic or photocatalytic properties), formulated to circumvent this drawback and their cracking during drying, through a surfactant-assisted synthesis. The consolidants were applied on Noto stone, a biocalcarenite (~95% CaCO3 ) employed in numerous Cultural Heritage buildings of Southern Italy. A comprehensive validation of the three consolidants, compared to a commercial TEOS based consoli…

A Novel Technique for Monitoring the W-Beam Guardrails

2014

The paper addresses the problem of the measurement of guardrails’ deformations by means automatic analysis of optical images. The technique is founded on the analysis of high-resolution photos, obtained by means of 3D camera installed into a data vehicle. The novel methodology has been used to calculate the longitudinal safety barrier deformations for one W-beam guardrails installed along a rural road in Italy. The procedure has shown that digital image analysis can be used with the aim to monitoring guardrails and, therefore, for guarantee reasonable levels of protection against serious ran-off-road crashes.

Iron-containing phases in metallurgical and coke dusts as well as in bog iron ore

2017

Abstract Several samples of dusts from steel and coke plants (collected mostly with electro filters) were subjected to the investigation of content of mineral phases in their particles. Additionally, sample of bog iron ore and metallurgical slurry was studied. Next, the magnetic susceptibility of all the samples was determined, and investigations of iron-containing phases were performed using transmission Mössbauer spectrometry. The values of mass-specific magnetic susceptibility χ varied in a wide range: from 59 to above 7000 × 10−8 m-3·kg−1. The low values are determined for bog iron ore, metallurgical slurry, and coke dusts. The extremely high χ was obtained for metallurgical dusts. The …

Analyses of single- and two-phase flow pressure drops in helical pipes using a modified RELAP5 code

2012

Abstract Thermal fluid dynamics analyses on single- and two-phase flows in helical pipes of steam generators to be used in Generation III and IV nuclear reactors have been performed. The study concerned with experimental activities as well code simulations carried out in the framework of a collaboration between the Department of Energetics of the Polytechnic of Torino and the Department of Energy of the University of Palermo. The goal was the validation of models implemented in Relap5/Mod3.2β thermal–hydraulic advanced code to simulate the hydrodynamic behaviour of helical pipe components in spite of the one-dimensional nature of the code. It is shown that much of the experimental data obta…