104 research outputs found
Speed of sound measurements in deuterium oxide (D 2 O) at temperatures between (276.97 and 363.15) K and at pressures up to 210 MPa
partially_open3embargoed_20211119Lago Simona, Giuliano Albo Paolo Alberto, Cavuoto GiuseppeLago, Simona; GIULIANO ALBO, PAOLO ALBERTO; Cavuoto, Giusepp
Speed of sound measurements in deuterium oxide (D2O) at temperatures between (276.97 and 363.15) K and at pressures up to 210 MPa
This paper presents speed of sound measurements in heavy water (deuterium oxide, ) along six isotherms between 276.97 K and 363.15 K for pressures up to 210 MPa using a double pulse-echo method. The experimental apparatus was validated measuring the speed of sound in ordinary water at ambient pressure and at temperatures between 295.5 K and 363.15 K with results found in agreement with values calculated from the reference equation of state for water by Wagner and Pruß within 0.005%. The relative combined expanded uncertainty of our speed of sound measurements, at a confidence level of 95%, is estimated to be less than 0.03% for pressures up to 10 MPa and in the order of 0.05% for pressures up to 210 MPa in the whole investigated temperature range. The speed of sound results have been compared with values calculated from the reference equation for heavy water the IAPS84 Formulation by Hill et al. (1982), and with the prediction of the newly developed equation of state for heavy water by Herrig et al. (2018). The relative deviations of these comparison were found to be consistent with the reference equations within their combined uncertainty. The results presented here were also compared with the most recent data by Wegge et al. and found to be in agreement within 0.05%
Thermodynamic properties of cis-1-chloro-2,3,3,3-tetrafluoro-1-propene [R-1224yd(Z)]: Experimental measurements of the density and speed of sound and modeling with the Patel–Teja equation of state
High-Pressure Speed of Sound Measurements of trans-1-Chloro-3,3,3-trifluoropropene (R1233zd(E)) in Liquid Region for Temperature from (273.15 to 353.15) K
This paper presents speed of sound
measurements of liquid trans-1-chloro-3,3,3-trifluoropropene
(R1233zd(E)) along
six isotherms over the temperature range from (273.15 to 353.15) K
for pressures up to 35 MPa by means of the double pulse–echo
method. The expanded uncertainty of the speed of sound measurements
at a confidence level of 95% is 0.1%. The experimental results were
compared with predictions from the state-of-the-art Fundamental Helmholtz
Energy equation of state [Mondéjar, M.E.; McLinden, M.O.; Lemmon,
E.W., Thermodynamic Properties of trans-1-Chloro-3,3,3-trifluoropropene
(R1233zd(E)): Vapor Pressure, (p,ρ,T) Behavior, and Speed of Sound Measurements, and Equation
of State. J. Chem. Eng. Data, 2015, 60, 2477–2489]
Temperature Increase Dependence on Ultrasound Attenuation Coefficient in Innovative Tissue-mimicking Materials
Although high intensity focused ultrasound beams (HIFU) have found rapid agreement in clinical environment as a tool for non
invasive surgical ablation and controlled destruction of cancer cells, some aspects related to the interaction of ultrasonic waves
with tissues, such as the conversion of acoustic energy into heat, are not thoroughly understood. In this work, innovative tissue-
mimicking materials (TMMs), based on Agar and zinc acetate, have been used to conduct investigations in order to determine a
relation between the sample attenuation coefficient and its temperature increase measured in the focus region when exposed to an
HIFU beam. An empirical relation has been deduced establishing useful basis for further processes of validations of numerical
models to be adopted for customizing therapeutic treatments
Determination of the Boltzmann constant k from the speed of sound in helium gas at the triple point of water
partially_open6The Boltzmann constant k has been determined from a measurement of the speed of sound in helium gas in a quasi-spherical resonator (volume 0.5 l) maintained at a temperature close to the triple point of water (273.16 K). The acoustic velocity c is deduced from measured acoustic resonance frequencies and the dimensions of the quasi-sphere, the latter being obtained via simultaneous microwave resonance. Values of c are extrapolated to the zero pressure limit of ideal gas behaviour. We find J⋅K−1, a result consistent with previous measurements in our group and elsewhere. The value for k, which has a relative standard uncertainty of 1.02 ppm, lies 0.02 ppm below that of the CODATA 2010 adjustment.mixedPitre, L; Risegari, L; Sparasci, F; Plimmer, M D; Himbert, M E; Giuliano Albo, P APitre, L; Risegari, L; Sparasci, F; Plimmer, M D; Himbert, M E; Giuliano Albo, P
The IMERAPlus Joint Research Project For Determinations Of The Boltzmann Constant
Abstract. To provide new determinations of the Boltzmann constant, k, which has been asked for by the International Committee for Weights and Measures concerning preparative steps towards new definitions of the kilogram, the ampere, the kelvin and the mole, an iMERAPlus joint research project has coordinated the European activities in this field. In this major European research project the Boltzmann constant has been determined by various methods to support the new definition of the kelvin. The final results of the project are reviewed in this paper. Determinations of the Boltzmann constant k were achieved within the project by all three envisaged methods: acoustic gas thermometry, Doppler broadening technique, and dielectric constant gas thermometry. The results were exploited by the interdisciplinary Committee on Data for Science and Technology (CODATA) in their 2010 adjustment of recommended values for fundamental constants. As a result, the CODATA group recommended a value for k with a relative standard uncertainty about a factor of two smaller than the previous u(k)/k of 1.7×10 −6
EXPERIMENTAL SPEED OF SOUND MEASUREMENTS IN LIQUID METHANE AT CRYOGENIC TEMPERATURE
The density of liquefied natural gas (LNG) is usually being calculated based on the composition
and an equation of state. In the absence of an accurate composition measurement, the density
is also commonly, but roughly, determined by the Coriolis or Ultrasonic Flow Meter (USM)
used for the flow rate measurements. The calculation of density has a rather large uncertainty
(between 0.2% - 0.5%, not including the uncertainty of the composition measurement), be-
cause the applied Equations of State are not yet validated at a sufficient low level of uncertainty.
As a part of an on-going European research project (called ”Metrology for LNG III - Metro-
logical support for LNG and LBG as a transport fuel”) to promote the large scale use of LNG
and liquefied biogas (LBG) as a transport fuel, the Italian Metrological Institute (INRiM) has
developed a new on-line density and speed of sound ultrasonic sensor. The novel sensors,
having the aim to improve the accuracy and reduce the measurement uncertainty of LNG
density and speed of sound measurements, can work both in laboratory controlled conditions
and in-field, it will be used for disseminating traceable density measurement when it is
mounted on the same industrial circuits where commercial sensors are installed.
Calibration tests have been carried out both at ambient temperature, using water, and at
cryogenic temperature in a closed-loop cryostat, using methane.
In this paper accurate speed of sound measurements in liquid-phase methane in the tempera-
ture range of (100 and 150) K and for pressures up to 10 MPa are reported. These results, with
an associated uncertainty in the order of 0.1%, were compared with literature values and with
predictions of the dedicated equation of state
A recursive equation method for the determination of density and heat capacity: Comparison between isentropic and isothermal integration paths
Calcolo delle proprietà termodinamiche dei fluidi: il nuovo metodo delle equazioni ricorsive (REM)
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