scholarly journals Assessment of Piezoelectric Sensors for the Acquisition of Steady Melt Pressures in Polymer Extrusion

Fluids ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 66
Author(s):  
Sónia Costa ◽  
Paulo Teixeira ◽  
José Covas ◽  
Loic Hilliou
Keyword(s):  
Polymer Processing ◽  
Piezoelectric Transducers ◽  
Piezoelectric Sensors ◽  
Flow Curves ◽  
Signal Drift ◽  
Temperature And Pressure ◽  
Pressure Independent ◽  
Pressure Changes ◽  
Different Levels ◽  
Slit Die

Piezoelectric sensors have made their way into polymer processing and rheometry applications, in particular when small pressure changes with very fast dynamics are to be measured. However, no validation of their use for steady shear rheometry is available in the literature. Here, a rheological slit die was designed and constructed to allow for the direct comparison of pressure data measured with conventional and piezoelectric transducers. The calibration of piezoelectric sensors is presented together with a methodology to correct the data from the inherent signal drift, which is shown to be temperature and pressure independent. Flow curves are measured for polymers showing different levels of viscoelasticity. Piezoelectric slit rheometry is validated and its advantage for the rheology of thermodegradable materials with viscosity below 100 Pa·s is highlighted.

scholarly journals Compensation of phase drifts caused by ambient humidity, temperature and pressure changes for continuously operating interferometers

2019 ◽  
Vol 14 (11) ◽  
pp. P11016-P11016
Author(s):  
K.J. Brunner ◽  
J. Knauer ◽  
J. Meineke ◽  
M. Stern ◽  
M. Hirsch ◽  
...  
Keyword(s):  
Ambient Humidity ◽  
Temperature And Pressure ◽  
Pressure Changes

Colloid osmotic pressure changes of dog's blood exposed to different mixtures of CO2 and air

1978 ◽  
Vol 44 (2) ◽  
pp. 254-257 ◽  
Author(s):  
Y. Kakiuchi ◽  
A. B. DuBois ◽  
D. Gorenberg
Keyword(s):  
Red Blood Cells ◽  
Osmotic Pressure ◽  
Cell Volume ◽  
Blood Cells ◽  
Freezing Point ◽  
Colloid Osmotic Pressure ◽  
Red Cell ◽  
Freezing Point Depression ◽  
Pressure Changes ◽  
Different Levels

Hansen's membrane manometer method for measuring plasma colloid osmotic pressure was used to obtain the osmolality changes of dogs breathing different levels of CO2. Osmotic pressure was converted to osmolality by calibration of the manometer with saline and plasma, using freezing point depression osmometry. The addition of 10 vol% of CO2 to tonometered blood caused about a 2.0 mosmol/kg H2O increase of osmolality, or 1.2% increase of red blood cell volume. The swelling of the red blood cells was probably due to osmosis caused by Cl- exchanged for the HCO3- which was produced rapidly by carbonic anhydrase present in the red blood cells. The change in colloid osmotic pressure accompanying a change in co2 tension was measured on blood obtained from dogs breathing different CO2 mixtures. It was approximately 0.14 mosmol/kg H2O per Torr Pco2. The corresponding change in red cell volume could not be calculated from this because water can exchange between the plasma and tissues.

DECOMPOSITION PRESSURES OF FERRIC SULPHATE AND ALUMINUM SULPHATE

1960 ◽  
Vol 38 (11) ◽  
pp. 2196-2202 ◽  
Author(s):  
N. A. Warner ◽  
T. R. Ingraham
Keyword(s):  
Gas Phase ◽  
Static System ◽  
Ferric Sulphate ◽  
Kcal Mole ◽  
Aluminum Sulphate ◽  
Temperature And Pressure ◽  
Pressure Changes ◽  
Mercury Manometer ◽  
Decomposition Pressure ◽  
Gas Pressures

The gas pressures over samples of anhydrous ferric sulphate and anhydrous aluminum sulphate have been measured in a static system, using a mercury manometer in which the exposed surface was covered with a flexible Pyrex bellows. The calculated ΔH for the decomposition of Fe2(SO4)3 was +135.4 kcal/mole. It was not possible to calculate the ΔH for the Al2(SO4)3 decomposition, because a discrete aluminum oxide with singular thermodynamic properties was not obtained.In the Fe2(SO4)3 system, the fraction of SO3 in the gas phase was found to be almost constant over the range of temperature and pressure changes used in the study.At any given temperature, the decomposition pressure over a ferric sulphate sample is greater than that over an aluminum sulphate sample, thus indicating that preferential decomposition of ferric sulphate should be thermodynamically feasible in mixtures of ferric sulphate and aluminum sulphate.

Epidural versus subdural spinal cord cooling: cerebrospinal fluid temperature and pressure changes

2000 ◽  
Vol 70 (1) ◽  
pp. 222-227 ◽  
Author(s):  
Sven A Meylaerts ◽  
Cor J Kalkman ◽  
Peter de Haan ◽  
Marjolein Porsius ◽  
Michael J.H.M Jacobs
Keyword(s):  
Spinal Cord ◽  
Cerebrospinal Fluid ◽  
Fluid Temperature ◽  
Temperature And Pressure ◽  
Pressure Changes

Modelling of Piezoelectric Transducers for Environmental Monitoring

2017 ◽  
Author(s):  
Constantine Bazilo ◽  
Alvydas Zagorskis ◽  
Oleg Petrishchev ◽  
Yulia Bondarenko ◽  
Vasyl Zaika ◽  
...  
Keyword(s):  
Environmental Monitoring ◽  
Quantitative Description ◽  
Well Being ◽  
Negative Influence ◽  
Piezoelectric Transducers ◽  
Piezoelectric Sensors ◽  
World Health ◽  
Physical Factors ◽  
Axially Symmetric ◽  
Health Organization

World Health Organization (WHO) defined health as being “a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity”. Physical factors (noise, vibration, electromagnetic fields, ionized radiation, etc.) may have a negative influence on both the environment and the health of population. Piezoelectric sensors have been employed in different fields such as medical analysis, environmental monitoring, etc. The object of the research is piezoelectric sensors for environmental monitoring and their simulation. Currently, there are no reliable and valid methods of constructing of mathematical models of piezoelectric transducers, which could be used as a theoretical basis for calculating characteristics and parameters of this class of functional elements of modern piezoelectronics. In most papers the described methods of transformers simulation are mostly based on the use of equivalent electrical circuits and it does not allow analysing stress-strain state of solids with piezoelectric effects. The final goal of mathematical modelling of vibrating piezoelectric elements is a qualitative and quantitative description of characteristics and parameters of existing electrical and elastic fields. Physical processes in piezoelectric transducers which occur using axially symmetric radial oscillations of piezoceramic disk are considered.

Analysis of Hot Oil Pipeline Stress Influencing Factors

2014 ◽  
Vol 887-888 ◽  
pp. 899-902
Author(s):  
Xiao Nan Wu ◽  
Shi Juan Wu ◽  
Hong Fang Lu ◽  
Jie Wan ◽  
Jia Li Liu ◽  
...  
Keyword(s):  
Crude Oil ◽  
High Viscosity ◽  
Analysis Model ◽  
Long Distance ◽  
Oil Pipeline ◽  
Software Analysis ◽  
Key Points ◽  
Temperature And Pressure ◽  
Pressure Changes ◽  
The Impact

In order to reduce the viscosity of crude oil for transport, we often use the way of heating delivery for high pour point, high wax, and high viscosity oil. Crude oil at high temperature, through long-distance transmission, the temperature and pressure changes on the piping stress greater impact. In this paper, in order to explore the main factor of hot oil pipeline stress and the location of key points, we build the XX hot oil pipeline stress analysis model used CAESAR II software, analysis of the impact of changes in temperature and pressure on piping stress when hot oil pipeline running, draw hot oil pipeline stress distribution, clearly identifies the location of key points of stress concentration, and we have come to that temperature is a major factor in generating pipe stress.

Microstructure Evolution Across Interfaces of Heterogeneous Metal Systems Under Ultrasonic Impact

2004 ◽  
Vol 854 ◽  
Author(s):  
Youhong Li ◽  
Yinon Ashkenazy ◽  
Robert S. Averback
Keyword(s):  
Large Scale ◽  
Shock Loading ◽  
Interfacial Strength ◽  
Interface Layer ◽  
Structural Defects ◽  
Interfacial Region ◽  
Heterogeneous Model ◽  
Interfacial Defects ◽  
Temperature And Pressure ◽  
Pressure Changes

ABSTRACTLarge-scale Molecular Dynamics (MD) studies on heterogeneous, model metal systems subjected to intense shock loading by a flyer plate were carried out. Of interest here is the effect of structural defects on interfacial strength under these extreme conditions. The metal target and flyer were essentially single crystals of Cu, but an interface layer was created by varying the mass of the Cu atoms in part of the sample. Interfacial defects in the form of vacancies, and at different concentrations, were introduced into the interfacial region. In addition to microstructural evolution of damage in this system, the shock induced temperature and pressure changes were also analyzed.

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