Investigating the Consistency of Asphalt Density Measurement Methods Over a Wide Range of Air Voids

2014 ◽  
Vol 42 (3) ◽  
pp. 20130157 ◽  
Author(s):  
Isaac L. Howard ◽  
Jesse D. Doyle
Keyword(s):  
Density Measurement ◽  
Measurement Methods ◽  
Air Voids ◽  
Wide Range

Computation of Thermodynamic Properties of Carbon Dioxide in the Range 0–750 Deg C

1970 ◽  
Vol 92 (3) ◽  
pp. 301-309 ◽  
Author(s):  
G. Angelino ◽  
E. Macchi
Keyword(s):  
Carbon Dioxide ◽  
Thermal Properties ◽  
High Temperature ◽  
Thermodynamic Properties ◽  
Thermodynamic Functions ◽  
Critical Region ◽  
Density Measurement ◽  
Working Fluid ◽  
Power Cycles ◽  
Wide Range

The computation of power cycles employing carbon dioxide as working fluid and extending down to the critical region requires the knowledge of the thermodynamic properties of CO2 within a wide range of pressures and temperatures. Available data are recognized to be insufficient or insufficiently accurate chiefly in the vicinity of the critical dome. Newly published density and specific heat measurements are employed to compute thermodynamic functions at temperatures between 0 and 50 deg C, where the need of better data is more urgent. Methods for the computation of thermal properties from density measurement in the low and in the high temperature range are presented and discussed. Results are reported of the computation of entropy and enthalpy of CO2 in the range 150–750 deg C and 40–600 atm. The probable precision of the tables is inferred from an error analysis based on the generation, by means of a computer program of a set of pseudoexperimental points which, treated as actual measurements, yield useful information about the accuracy of the calculation procedure.

Comparison of In Situ Current Measurement Methods, the Accuracy Achieved in the Field and Recommendations for Engineering Design Applications

2018 ◽  
Author(s):  
Gregory Bush ◽  
Carey Nolan
Keyword(s):  
Engineering Design ◽  
Current Data ◽  
Measurement Methods ◽  
Significant Error ◽  
Acoustic Backscatter ◽  
Poor Agreement ◽  
Significant Cost ◽  
Wide Range ◽  
Comparison Data

Here we present a wealth of comparison data from acoustic backscatter current meters against current meters that use an active acoustic path (the RPS CM04). The data cover a wide range of environmental conditions. Very poor agreement between current meters frequently occurs, presenting as both bias and noise. The causes of the differences remain unproven, although for acoustic profilers deployed in deep water, failure of the assumption of the same flow in all beams is a possible source of significant error. As a result of decade’s worth of comparisons plagued with unexplained differences, we have reduced confidence in the accuracy of current data collected by acoustic backscatter sensors. We therefore avoid (where practical) using these instruments when the application of the current data is for engineering design, where uncertainty in accuracy can have significant cost or risk consequences.

Suborbital probes

1969 ◽  
Vol 308 (1493) ◽  
pp. 243-257
Keyword(s):  
Density Measurement ◽  
Cosmic Ray ◽  
Sounding Rockets ◽  
The Past ◽  
Black Brant ◽  
Wide Range ◽  
Almost All ◽  
Technological Limitations ◽  
Rate Of Success ◽  
Further Development

Over the past decade sounding rockets have offered scientists a relatively economical means of carrying useful payloads up to altitudes of 250 km and above. The range of rockets available in the U. S., France, U. K., Japan, for example, is great; names such as Aerobee, Areas, Nike Apache, Centaure, Dragon, Black Brant, Skylark, Petrel, Skua, Kappa will be familiar to all associated with sounding rockets. Further, within this wide range of named varieties almost all have a range of variants ; with the result that it has been possible to carry out many different experiments such as density measurement, cosmic ray investigations and observations of the atmosphere from above. As an indication of the total number of firings, it is possible to cite Skylark with nearly 200 launches to date with an excellent rate of success. It is the purpose of this review to look forward to the next decade, to attempt to indicate to the scientist what forms of vehicles and facilities he can be offered in the future, and also to emphasize the technological limitations from which we cannot escape. It is hoped that by a better understanding of these the scientist will be able to frame his requirements in such a manner that maximum over-all cost effectiveness can be realized and secondly that we in industry should arrive at an appreciation of where further development is required.

scholarly journals First density comparison on viscoelastic samples by oscillation-type densimetry

ACTA IMEKO ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 79
Author(s):  
A. Furtado ◽  
J. Pereira ◽  
R. Quendera ◽  
M. Schiebl ◽  
E. Lenard ◽  
...  
Keyword(s):  
International Comparison ◽  
Density Measurement ◽  
Measurement Methods ◽  
Newtonian Fluids ◽  
Density Measurements ◽  
Oscillation Type ◽  
Hydrostatic Weighing ◽  
Damping Effects

To provide a deeper insight about the damping effects produced by the viscoelasticity of non- Newtonian fluids during density measurements with oscillation-type density meters, and about how reference laboratories overcome these effects, an international comparison was performed, within the scope of the EMPIR Project 17RPT02 rhoLiq. The results of the comparison evidenced the possibility to measure density of viscoelastic samples by means of oscillation-type density meters with an uncertainty between 0.10 kg·m<sup>-3</sup> and 0.25 kg·m<sup>-3</sup>. However, these instruments may be able to reach lower uncertainties if compared with higher precision density measurement methods such as hydrostatic weighing.

scholarly journals Evaluation of the Potential of Sasobit REDUX Additive to Lower Warm-Mix Asphalt Production Temperature

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1285 ◽  
Author(s):  
Arminda Almeida ◽  
Michela Sergio
Keyword(s):  
Construction Industry ◽  
Road Construction ◽  
Warm Mix Asphalt ◽  
Asphalt Mixtures ◽  
Asphalt Production ◽  
Air Voids ◽  
Health Concerns ◽  
The Road ◽  
Wide Range ◽  
Production Temperature

Environmental and health concerns have been increasing in the road construction industry. This industry has provided several techniques and a wide range of additives to lower the production temperatures of asphalt mixtures, generating, among others, a new mix type called warm-mix asphalt (WMA). This paper aims to evaluate the potential of the Sasobit REDUX additive to lower the production temperatures of WMA. This additive, which is an alternative to the well-known Sasobit, is completely soluble in bitumen at temperatures above 85 °C while the same temperature for the Sasobit is 115 °C. For that reason, three target compaction temperatures were considered (90, 100 and 110 °C) and both Marshall and compactability tests were carried out. A hot-mix asphalt (HMA) was tested in parallel for comparison. It was concluded that the volumetric properties (air voids content about 4%) and the Marshall properties (stability about 11 kN, flow about 4 mm and Marshall quotient higher than 2 kN/km) of the Sasobit REDUX-WMA were globally satisfactory. In relation to the compactability test, the Sasobit REDUX-WMA mixtures were relatively easier to be compacted compared to the HMA mixture. The three Sasobit REDUX-WMA mixtures (90, 100 and 110 °C) exhibited a very similar compactability (differences lower than 0.4%). Therefore, it seems reasonable to conclude that the Sasobit REDUX has potential to lower WMA production temperatures by 20 °C. A reduction of that magnitude would lead to significant environmental gains.

Sign in / Sign up

Export Citation Format

Share Document