We present an experimental systematics study of a polarimetric method for measuring the vacuum magnetic birefringence based on a pair of rotating half-wave plates. The presence of a systematic effect ...at the same frequency as the sought for magneto-optical effect inhibits the use of strictly constant magnetic fields. We characterise this systematic, discuss its origin and propose a viable workaround.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The main purpose of the HeLLo project is to contribute to data available on the literature on the real hygrothermal behavior of historic walls and the suitability of insulation technologies. ...Furthermore, it also aims at minimizing the energy simulation errors at the design phase and at improving their conservation features. In this framework, one of the preliminary activities of the study is the creation of a real in situ hot box to measure and analyze different insulation technologies applied to a real historic wall, to quantify the hygrothermal performance of a masonry building. Inside this box, ‘traditional’ experiments can be carried out: recording heat flux, surface temperature, and air temperatures, as well as relative humidity values through the use of a new sensing system (composed of thermocouples and temperature/relative humidity combined sensors). Within this paper, the process of development, construction, and validation of this new metering box is exhibited. The new hot box, specifically studied for historic case studies, when compared to other boxes, presents other advantages compared to previous examples, widely exemplified.
The hygrothermal behaviour of an internally insulated historic wall is still hard to predict, mainly because the physical characteristics of the materials composing the historic wall are unknown. In ...this study, the hygrothermal assessment of an internally thermal insulated masonry wall of an historic palace located in Ferrara, in Italy, is shown. In situ non-destructive monitoring method is combined with a hygrothermal simulation tool, aiming to better analyse and discuss future refurbishment scenarios. In this context, the original U-value of the wall (not refurbished) is decreased from 1.44 W/m2K to 0.26 W/m2K (10 cm stone wool). Under the site specific conditions of this wall, not reached by the sun or rain, it was verified that even in the absence of vapour barrier, no frost damage is likely to occur and the condensation risk is very limited. Authors proposed further discussion based on simulation. The results showed that the introduction of a second gypsum board to the studied technology compensated such absence, while the reduction of the insulation material thickness provides a reduction of RH peaks in the interstitial area by 1%; this second solution proved to be more efficient, providing a 3% RH reduction and the avoidance of further thermal losses.
GeoTh is a new, simple, efficient, flexible, low-cost experimental laboratory apparatus. These features make it an excellent technological tool for measuring the thermal conductivity of granular ...materials, e.g., soils, sand, silt, clay or artificial composites. In particular, a configuration based on the one-dimensional heat conduction in steady-state regime was designed, built, and assembled to determine the thermal conductivity of the samples. In addition, we developed two user-friendly codes; the first for acquisition of the technical data (time series of air temperature; samples temperatures; and heat power); and the second relative to the elaboration of collected data and the calculation of the physical and thermophysical parameters of each analyzed sample (porosity, bulk density, % of water saturation, thermal conductivity, thermal diffusivity). The developed apparatus allows us to temporarily carry out measurements from one to six samples either in ambient conditions or at constant temperature. The robustness of the system has been tested by analyzing and measuring numerous materials in different conditions. We also performed several tests by varying the water content (between 0% and 100% water saturation) for sandy and silty-sand samples to calibrate and test the robustness of the system as well as for verifying the repeatability of the analytical data. Finally, the obtained thermal conductivity values are compared with other dataset proposed in the literature, showing a good fit.
•New study on the hygrothermal performance of retrofitted historic walls without a vapour barrier;•In situ monitoring campaign between November 15th 2019 and September 30th 2020;•Field data was used ...for the calibration of 2D hygrothermal simulation models;•No risk of frost damage or interstitial condensation was objectively proved.
This paper presents the newly developed study, methodology and assessment of the hygrothermal performance of a historic building wall retrofitted with three different internal insulation technologies, without a vapour barrier. It aims at assessing any possible condensation problems at the most critical point of the tested stratigraphy (namely, in between the wall and the insulation material) and to limit the modification of the original hygrothermal behaviour of the original wall’s materials with the addition of a vapour layer, as would commonly be used. This evaluation was performed through in situ measurements and dynamic software simulations. In situ data was used for calibrating the 2D simulation model conducted with Delphinsoftware 6.0.20.
Under the climatic conditions in Ferrara (Italy), the results of both the in-situ monitoring and simulation evidenced no risk of frost damage to the building’s original wall. With regards to the risk of interstitial condensation, simulations showed no high risk even in the absence of a water vapour barrier. Additionally, the amount of water vapour collected during the winter season dried out during the spring/summer period.
This article aims to properly assess the hygrothermal properties of walls located in historic buildings, this study discloses the development of a remote sensing technology compatible with an in-situ ...measurement implemented in Palazzo Tassoni (Italy). As required by the international recommendations adapted to cultural heritage (CH), this monitoring system balances CH conservation, performance aspects and economic costs using an integrated multidisciplinary approach. Electronics for measurement of environmental parameters is composed of sensor measurements, data acquisition system and data storage and communication system. Data acquisition system, equipped with standard modbus-rtu interface, is designed to run standalone and it is based on two cloned single board PCs to reduce the possibility of data loss. In order to reduce the costs, RaspberryPI single board PCs were chosen. These run a C/C++ software based on standard modbus library and designed to implement multi-client server TCP/IP to allow communication with other devices. Storage and communication systems are based on an industrial PC; it communicates with sensor measurements’ system through a modbus-TCPIP bridge. PC runs a Labview software to provide data storage on a local database and graphical user interface to properly see all acquired data. Herein, some sensing options and approaches of measurement are described, unveiling different possible ways of enhancing the retrofit of CH with adapted technology.
•Novel application of strain-gauge plethysmography to monitor the cerebral venous outflow.•Capacitive sensors powered through a constant current to measure sensor elongation.•Experiment of human ...physiology aboard the International Space Station.
We present a novel application of strain-gauge plethysmography that is suitable to detect blood volume variations in the human venous system. The plethysmography system uses capacitive sensors that are electrically connected to a portable electronic unit to record changes of blood volume over time. Such system has been developed within a project that aimed to monitor the cerebral venous return of the astronaut during an experiment on the International Space Station. In this work, we describe the novel solution in which measurement of elongation is directly obtained by charging the sensor capacitance with a constant current. We also report the full characterization of the plethysmography system and an example of the experimental protocol that has been performed in microgravity condition. Remarkably, the system we propose is able to detect cross-sectional area variations of neck veins with enough sensitivity to be useful for studies concerning cardiac oscillations.
Abstract
Signal-induced noise is observed in Hamamatsu R11265
Multianode Photomultiplier Tubes, manifesting up to several
microseconds after the single photoelectron response signal and
localised in ...specific anodes. The mean number of noise pulses varies
between devices, and shows significant dependence on the applied
high-voltage. The characterisation of this noise and the mitigation
strategies to perform optimal single-photon counting at 40 MHz, as
required by the LHCb Ring-Imaging Cherenkov detectors, are
reported.
The ELI-NP (Extreme Light Infrastructure-Nuclear Physics) facility, currently under construction near Bucharest (Romania), is the pillar of the project ELI dedicated to the generation of ...high-brilliance gamma beams and high-power laser pulses that will be used for frontier research in nuclear physics. To develop an experimental program at the frontiers of the present-day knowledge, two pieces of equipment will be deployed at ELI-NP: a high power laser system consisting of two 10 PW lasers and a high brilliance gamma beam system. The ELI-NP Gamma beam system will deliver an intense gamma beam with unprecedented specifications in terms of photon flux, brilliance and energy bandwidth in an energy range from 0.2 to 20 MeV. Such a gamma beam requires special devices and techniques to measure and monitor the beam parameters during the commissioning and the operational phase. To accomplish this task, the Gamma Beam Characterization System, equipped with four elements, was developed: a Compton spectrometer (CSPEC), to measure and monitor the photon energy spectrum; a nuclear resonant scattering system (NRSS), for absolute beam energy calibration and inter-calibration of the other detectors; a beam profile imager (GPI) to be used for alignment and diagnostics purposes; and finally a sampling calorimeter (GCAL), for a fast combined measurement of the beam average energy and intensity. The combination of the measurements performed by GCAL and CSPEC allows fully characterizing the gamma beam energy distribution and intensity with a precision at the level of few per mill, enough to demonstrate the fulfillment of the required parameters. This article presents an overview of the gamma beam characterization system with focus on these two detectors, which were designed, assembled and are currently under test at INFN-Firenze. The layout and the working principle of the four devices is described, as well as some of the main results of detector tests.
Thirty-three-thousand CLARO8 ASICs were produced in 0.35μm CMOS technology and will be installed in the upgraded LHCb detector at CERN. Radiation hardness has been extensively characterized and ...compared to prototype production.
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