Estimation of the error due to radial displacements in a conductivity cell (jones type)

2021 ◽  
Author(s):  
D. V. Meleshchuk
Keyword(s):  
Radial Displacements ◽  
Conductivity Cell

Micro-flowcell conductometric sweat analysis for cystic fibrosis diagnosis

2000 ◽  
Vol 37 (3) ◽  
pp. 399-407 ◽  
Author(s):  
H Lewis Webster ◽  
Carmelo G Quirante
Keyword(s):  
Power Supply ◽  
Time Interval ◽  
Sweating Rate ◽  
Sensor Cell ◽  
Sweat Testing ◽  
Small Holders ◽  
Flow Through ◽  
To Receive ◽  
Conductivity Cell ◽  
Sweat Tests

This paper describes a device specifically designed to facilitate neonatal sweat testing. The components are sized appropriately for attachment to the limbs of newborns. Iontophoretic electrodes, with pilocarpine gel inserts, are latched into small holders attached by straps to the limb. The holder at the anodic site remains in place to receive and align the sensor cell, which uses a conical collecting surface to channel the sweat directly and anaerobically from the sweat ducts to the continuous flow-through conductivity cell within its body. A crib-side analysis unit incorporates an iontophoretic power supply and displays a continuous readout of sweat electrical conductivity. The average conductivity during a specific time interval and the initial sweating rate are automatically displayed. The method, which simplifies sweat tests, is currently being assessed in three neonatal clinical trials to test its ability to reduce test failures in the newborn due to insufficient sweat.

Conductivity cell for temperature cycling of polymer electrolytes

1984 ◽  
Vol 11 (4) ◽  
pp. 301-303 ◽  
Author(s):  
R ARMSTRONG ◽  
M CLARKE
Keyword(s):  
Polymer Electrolytes ◽  
Temperature Cycling ◽  
Conductivity Cell

Rotordynamics Experimental Validation of a Sliding-Blade Architecture for an Inside-Out Ceramic Turbine

2018 ◽  
Author(s):  
C. Landry ◽  
B. Picard ◽  
T. Parent-Simard ◽  
J.-S. Plante ◽  
M. Picard
Keyword(s):  
Radial Displacement ◽  
Hoop Stress ◽  
Low Cost ◽  
Maximum Speed ◽  
Inlet Temperature ◽  
Radial Displacements ◽  
Axial Forces ◽  
Blade Tip ◽  
Inclined Planes ◽  
Inside Out

The integration of monolithic ceramic blades into sub-megawatt microturbines is a low-cost option for increasing Turbine Inlet Temperature and efficiency. The Inside-Out Ceramic Turbine (ICT) is a promising concept for the integration of ceramic blades by loading each blades in compression using a carbon-polymer composite rim to convert the blade radial loads to tangential hoop stress. High tangential velocities lead to elevated radial displacement of the rim and, therefore, the rotor hub needs to be able to maintain the contact with the blades for a large range of radial displacements. This displacements comes with hub structural challenges and rotordynamics considerations. For these reasons, blade tip speed have been previously limited to about 360 m/s. This paper presents a hub design that allows high radial displacement using the combination of inclined blade roots, inclined hub grooves and an axial spring. The contact between the blade root and the hub is maintained through the inclined planes by the axial forces from the spring creating internal friction in the rotor that can induce sub-synchronous rotordynamics instabilities. The onset of instabilities is investigated experimentally with cold spin tests of a simplified ICT prototype. The results first show that the concept remains stable up to the maximum speed tested of 127 kRPM (tip speed of 387 m/s) if the spring is designed such that it remains in contact with the blade roots at all time. On the other hand, when reducing the preload sufficiently to test the limits of the concept, the rotor first mode became unstable at 120 kRPM resulting in failure of the prototype. These results suggest that, provided a sufficient spring preload to prevent excessive relative motion, the blades can reach the desired radial displacements, removing the main constraint on ICT tip speed.

scholarly journals About uncertainties in practical salinity calculations

Ocean Science ◽  
2011 ◽  
Vol 7 (5) ◽  
pp. 651-659 ◽  
Author(s):  
M. Le Menn
Keyword(s):  
State Of The Art ◽  
Conductivity Ratio ◽  
Real Analysis ◽  
Error Sources ◽  
Current State ◽  
Laboratory Calibration ◽  
Temperature And Pressure ◽  
Conductivity Cell ◽  
Temperature Depth

Abstract. In the current state of the art, salinity is a quantity computed from conductivity ratio measurements, with temperature and pressure known at the time of the measurement, and using the Practical Salinity Scale algorithm of 1978 (PSS-78). This calculation gives practical salinity values S. The uncertainty expected in PSS-78 values is ±0.002, but no details have ever been given on the method used to work out this uncertainty, and the error sources to include in this calculation. Following a guide published by the Bureau International des Poids et Mesures (BIPM), using two independent methods, this paper assesses the uncertainties of salinity values obtained from a laboratory salinometer and Conductivity-Temperature-Depth (CTD) measurements after laboratory calibration of a conductivity cell. The results show that the part due to the PSS-78 relations fits is sometimes as significant as the instrument's. This is particularly the case with CTD measurements where correlations between variables contribute mainly to decreasing the uncertainty of S, even when expanded uncertainties of conductivity cell calibrations are for the most part in the order of 0.002 mS cm−1. The relations given here, and obtained with the normalized GUM method, allow a real analysis of the uncertainties' sources and they can be used in a more general way, with instruments having different specifications.

scholarly journals About uncertainties in practical salinity calculations

2009 ◽  
Vol 6 (3) ◽  
pp. 2461-2485 ◽  
Author(s):  
M. Le Menn
Keyword(s):  
State Of The Art ◽  
Actual State ◽  
Conductivity Ratio ◽  
Real Analysis ◽  
Laboratory Calibration ◽  
Temperature And Pressure ◽  
Conductivity Cell ◽  
Temperature Depth

Abstract. Salinity is a quantity computed, in the actual state of the art, from conductivity ratio measurements, knowing temperature and pressure at the time of the measurement and using the Practical Salinity Scale algorithm of 1978 (PSS-78) which gives practical salinity values S. The uncertainty expected on PSS-78 values is ±0.002, but nothing has ever been detailed about the method to work out this uncertainty, and the sources of errors to include in this calculation. Following a guide edited by the Bureau International des Poids et Mesures (BIPM), this paper assess, by two independent methods, the uncertainties of salinity values obtained from a laboratory salinometer and Conductivity-Temperature-Depth (CTD) measurements after laboratory calibration of a conductivity cell. The results show that the part due to the PSS-78 relations fits is sometimes as much significant as the instruments one's. This is particularly the case with CTD measurements where correlations between the variables contribute to decrease largely the uncertainty on S, even when the expanded uncertainties on conductivity cells calibrations are largely up of 0.002 mS/cm. The relations given in this publication, and obtained with the normalized GUM method, allow a real analysis of the uncertainties sources and they can be used in a more general way, with instruments having different specifications.

scholarly journals Vaccinium gaultherioides: Another insight into water relations of alpine dwarf shrubs

2015 ◽  
Vol 2 ◽  
pp. e004 ◽  
Author(s):  
Andrea Ganthaler ◽  
S. Mayr
Keyword(s):  
Growth Form ◽  
Current Knowledge ◽  
European Alps ◽  
Hydraulic Parameters ◽  
Turgor Loss Point ◽  
Dwarf Shrubs ◽  
Hydraulic Safety ◽  
Conductivity Cell ◽  
Osmotic Properties ◽  
Insight Into

Dwarf shrubs exhibit different requirements for a safe and efficient water supply compared to trees due their basitonic branching and low growth height. Though, only few studies dealt with the hydraulics of this growth form. Here we report key hydraulic parameters (vulnerability to drought-induced embolism, xylem hydraulic conductivity, cell osmotic potential, potential at turgor loss point) and related wood anatomical traits for Vaccinium gaultherioides, a wide-spread species in the European Alps. The results affirm the current knowledge, by indicating a relatively risky hydraulic strategy with low hydraulic safety compared to alpine trees and osmotic properties connected to the species’ soil humidity requirements.

scholarly journals Numerical Simulation of Natural Convection in a Transient Short-Hot-Wire Thermal Conductivity Cell

Netsu Bussei ◽  
2008 ◽  
Vol 22 (4) ◽  
pp. 217-222 ◽  
Author(s):  
Peter L. Woodfield ◽  
Jun Fukai ◽  
Motoo Fujii ◽  
Yasuyuki Takata ◽  
Kanei Shinzato
Keyword(s):  
Thermal Conductivity ◽  
Numerical Simulation ◽  
Natural Convection ◽  
Hot Wire ◽  
Transient Short Hot Wire ◽  
Thermal Conductivity Cell ◽  
Conductivity Cell

Design of an AC Conductivity Measurement Setup for Sensor Materials Characterization

2014 ◽  
Vol 4 (2) ◽  
pp. 1-7
Author(s):  
Nisha Rajappan ◽  
K.N. Madhusoodanan
Keyword(s):  
Material Characterization ◽  
Ac Conductivity ◽  
Gas Sensing ◽  
Conductivity Measurement ◽  
Sensor Material ◽  
Semiconductor Gas Sensor ◽  
Sensor Materials ◽  
Set Up ◽  
Sensing Characteristics ◽  
Conductivity Cell

AC conductivity measurement can be an effective method for the study of sensor material characteristics for gas sensing. The authors have designed and fabricated a sensitive set up for sensor material characterization using ac conductivity measurement. The set up fabricated is employed for bulk samples. AC conductivity cell with cold fingertip that can facilitate measurement in the range 80 K to 500 K has been fabricated. The necessary vacuum lines and gas feed throughs are provided in order to study the gas sensing characteristics of semiconductor gas sensor materials. A programmable PID temperature controller and the necessary signal conditioning circuits are designed and incorporated into the system. AC conductivity measurement is carried out using Fluke PM 6306 impedance analyzer.

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