Search results for "Measurements"

Using Beerkan experiments to estimate hydraulic conductivity of a crusted loamy soil in a Mediterranean vineyard

2019

Abstract In bare soils of semi-arid areas, surface crusting is a rather common phenomenon due to the impact of raindrops. Water infiltration measurements under ponding conditions are becoming largely applied techniques for an approximate characterization of crusted soils. In this study, the impact of crusting on soil hydraulic conductivity was assessed in a Mediterranean vineyard (western Sicily, Italy) under conventional tillage. The BEST (Beerkan Estimation of Soil Transfer parameters) algorithm was applied to the infiltration data to obtain the hydraulic conductivity of crusted and uncrusted soils. Soil hydraulic conductivity was found to vary during the year and also spatially (i.e., ro…

X-ray absorption spectroscopy study of local dynamics and thermal expansion in ReO3

2015

The thermal expansion of polycrystalline ${\mathrm{ReO}}_{3}$ is studied in vacuum by x-ray diffraction from 300 to 600 K and by extended x-ray absorption fine structure (EXAFS) at the Re ${L}_{3}$ edge from 30 to 600 K. A detailed EXAFS analysis is presented up to the sixth coordination shell around Re. The crystal thermal expansion is weak throughout the explored range, negative below 100 K, positive from 150 to 500 K, and negative again above 500 K. The analysis of mean square relative displacements obtained by EXAFS and of mean square displacements available from x-ray and neutron diffraction measurements confirms the presence of significant static disorder in the investigated samples. …

Non-destructive physical measurements for the study of museum environments and characterization of archaeological artifact

2014

OPTICAL PROPERTIES OF DEFECTS IN SILICA

2000

The optical properties of point defects are frequently the most important parameter in applications of glassy silica. They are relatively easy to measure on standard spectrophotometers and yield direct information on the quality of practical silica-based devices, e.g., attenuation of fiber-optic waveguides or ultraviolet (UV)- transmitting windows. However, optical measurements alone usually do not give enough information to establish the origin and atomic structure of the respective point defects.

Localization from inertial data and sporadic position measurements

2020

International audience; A novel estimation strategy for inertial navigation in indoor/outdoor environments is proposed with a specific attention to the sporadic nature of the non-periodic measurements. After introducing the inertial navigation model, we introduce an observer providing an asymptotic estimate of the plant state. We use a hybrid dynamical systems representation for our results, in order to provide an effective, and elegant theoretical framework. The estimation error dynamics with the proposed observer shows a peculiar cascaded interconnection of three subsystems (allowing for intuitive gain tuning), with perturbations occurring either on the jump or on the flow dynamics (depen…

Noise characterization of analog to digital converters for amplitude and phase noise measurements

2017

International audience; Improvements on electronic technology in recent years have allowed the application of digital techniques in phase noise metrology where low noise and high accuracy are required, yielding flexibility in systems implementation and setup. This results in measurement systems with extended capabilities, additional functionalities and ease of use. In most digital schemes the Analog to Digital Converters (ADCs) set the ultimate performance of the system, therefore the proper selection of this component is a critical issue. Currently, the information available in literature describes in depth the ADC features only at frequency offsets far from the carrier. However, the perfo…

Accelerometry - Simple, but challenging

2017

PQ Metrics Implementation on Low Cost Smart Metering Platforms. A Case Study Analysis

2018

The increasing interest on the quality of the energy supplied and generated in distribution networks is raising the need of distributed power quality (PQ) measurements. To allow such capabilities with cost effective metering solutions, this paper wants to investigate the feasibility of using smart meters, already installed for energy billing, also for power quality monitoring. To this aim, an electronic board (based on STCOMET metrology device), already used in many energy meters of different countries, has been selected as case study platform. The manufacturer firmware of this board was essentially aimed at implementing energy meter metrics and power line communications functionalities. In…

Short-time non-work-related computing and creative performance

2014

It has been argued that non-work-related computing (NWRC) takes time away from work and, hence, decreases work productivity. On the other hand, it has also been claimed that short-time non-work-related computing (STNWRC) (a maximum of 15 minutes), has a positive impact on work productivity, including relief from boredom, higher creativity, and the underlying recovery mechanisms. To examine the impact of STNWRC on creative performance, we draw on Fredrickson's broaden-and-build theory, the concept of recovery with mental well-being and low cognitive effort. A 2 × 2 factorial experiment with 40 subjects was conducted. The results indicate that STNWRC has a positive effect on creative performa…

The Influence of Fruit Ripening Stage at Harvest and Storage Temperature on ‘Bianca di Bivona’ White Flesh Peaches

2015

‘Bianca di Bivona’ is a white-flesh peach cultivar, which ripens during the last week of July and the first of August. Its fruit are known because of their distinct flavor and aroma, which make them highly accepted, particularly in the local markets. However, nothing is known about their postharvest physiology and storage conditions. In order to investigate the effect of: (a) fruit ripening stage at harvest and, (b) storage temperatures, ‘Bianca di Bivona’ peaches were picked at mature-green, (60.0±1.3 N), and ripe stage (30.7 ± 2.1 N) determined by flesh firmness, and then stored at 0°C and 5°C (90% RH). Flesh firmness, total soluble solids, titratable acidity, weight loss and DA index, me…