A Sensitivity Analysis of the Thermal Pulse Decay Method for Measurement of Local Tissue Conductivity and Blood Perfusion

1986 ◽  
Vol 108 (1) ◽  
pp. 54-58 ◽  
Author(s):  
H. Arkin ◽  
K. R. Holmes ◽  
M. M. Chen
Keyword(s):  
Sensitivity Analysis ◽  
Measurement Errors ◽  
Blood Perfusion ◽  
Maximum Error ◽  
Experimental Protocol ◽  
Tissue Conductivity ◽  
Thermal Pulse ◽  
Local Tissue ◽  
Tissue Heating

The Thermal Pulse Decay (TPD) method for the determination of local tissue thermal conductivity and blood perfusion rate is based on a comparison of measured with theoretically calculated temperatures. A sensitivity analysis of the theoretical model is performed. This analysis supports the establishment of an experimental protocol which reduces the measurement errors: An “optimal” measurement time inverval for typical perfusion rates (up to 6 mL/mL/min) was found to be between 3 and 11 s after the heat pulse is turned off. Within this interval, the maximum error in determination of tissue conductivity and blood perfusion caused by experimental measurement errors is expected not to exceed 5 percent. The presently chosen pulse duration of 3 s is in agreement with the analysis as a good compromise between accuracy and excessive tissue heating.

Thermal Pulse Decay Method for Simultaneous Measurement of Local Thermal Conductivity and Blood Perfusion: A Theoretical Analysis

1986 ◽  
Vol 108 (3) ◽  
pp. 208-214 ◽  
Author(s):  
H. Arkin ◽  
K. R. Holmes ◽  
M. M. Chen ◽  
W. G. Bottje
Keyword(s):  
Thermal Conductivity ◽  
Blood Flow ◽  
Theoretical Analysis ◽  
Simultaneous Measurement ◽  
Blood Perfusion ◽  
Perfusion Rate ◽  
Tissue Conductivity ◽  
Thermal Pulse ◽  
Measurement Protocol ◽  
Blood Perfusion Rate

Presented here is a theoretical analysis of the recently developed thermal pulse decay (TPD) method for a simultaneous measurement of local tissue conductivity and blood perfusion rate. The paper describes the theoretical model upon which the TPD method is based and details its capabilities and limitations. The theoretical aspects that affected the development of the measurement protocol are also discussed. The performance of the method is demonstrated with an experimental example which compares the measurements of local kidney blood perfusion rates made using the TPD method with the total renal blood flow obtained coincidentally using a blood flowmeter, in an anesthetized dog.

Determination of levitated molten metal shape in axisymmetric induction heating system using sensitivity analysis

1995 ◽  
Vol 31 (3) ◽  
pp. 2158-2161 ◽  
Author(s):  
Ghun-Deok Suh ◽  
Hong-Bae Lee ◽  
Song-Yop Hahn ◽  
Tae-Kyung Chung ◽  
Il-Han Park
Keyword(s):  
Sensitivity Analysis ◽  
Molten Metal ◽  
Induction Heating ◽  
Heating System ◽  
Induction Heating System ◽  
Metal Shape

scholarly journals High-Fidelity Sensitivity Analysis of Modal Properties of Mistuned Bladed Disks Regarding Material Anisotropy

2018 ◽  
Author(s):  
Adam Koscso ◽  
Guido Dhondt ◽  
E. P. Petrov
Keyword(s):  
Sensitivity Analysis ◽  
Finite Element ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Finite Element Models ◽  
Coordinate Systems ◽  
Bladed Disks ◽  
Bladed Disk ◽  
Material Orientation

A new method has been developed for sensitivity calculations of modal characteristics of bladed disks made of anisotropic materials. The method allows the determination of the sensitivity of the natural frequencies and mode shapes of mistuned bladed disks with respect to anisotropy angles that define the crystal orientation of the monocrystalline blades using full-scale finite element models. An enhanced method is proposed to provide high accuracy for the sensitivity analysis of mode shapes. An approach has also been developed for transforming the modal sensitivities to coordinate systems used in industry for description of the blade anisotropy orientations. The capabilities of the developed methods are demonstrated on examples of a single blade and a mistuned realistic bladed disk finite element models. The modal sensitivity of mistuned bladed disks to anisotropic material orientation is thoroughly studied.

scholarly journals Quantification of Fructans in Bioethanol Stillage Based On a Simplified Analytical Method

2021 ◽  
Author(s):  
Andreas Zimmermann ◽  
Martin Kaltschmitt
Keyword(s):  
Analytical Method ◽  
Measurement Errors ◽  
Process Development ◽  
Stationary Phases ◽  
New Approach ◽  
Sample Matrix ◽  
Sample Throughput ◽  
Complex Sample ◽  
Potential Substrate

Abstract Bioethanol stillage, the main by-product of industrial bioethanol production, is a potential substrate for fructans. However, the determination and quantification of fructans in such complex sample matrices is still a challenge for the corresponding analytics to be overcome in order to allow for the identification and utilisation of such unused fructan sources. Especially a possible utilisation or rather the corresponding process development requires appropriate analytics first. Thus, this paper aims to illuminate the basics of fructan quantification in stillage and the corresponding challenges particularly arising with widely used HPLC-RID systems. On this basis, a new approach for fructan quantification is presented based on such HPLC-RID systems allowing for a reliable and especially simple fructan determination in bioethanol stillage for comparably high sample throughput. The developed method performs fructan quantification by determination of fructose and glucose equivalents after a targeted acidic hydrolysis adapted to the respective sample matrix. By means of two different stationary phases, the problem of limited resolution in case of HPLC-RID is overcome and thus measurement errors are reduced. The approach towards the adapted analytical method can be transferred easily to comparable complex sample matrices.

Monte Carlo method for the reduction of measurement errors in the material parameter estimation with cavities

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ronny Peter ◽  
Luca Bifano ◽  
Gerhard Fischerauer
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Measurement Errors ◽  
Input Data ◽  
Material Parameter ◽  
Cavity Resonator ◽  
Calculation Algorithm ◽  
The Monte Carlo Method ◽  
Electromagnetic Resonances

Abstract The quantitative determination of material parameter distributions in resonant cavities is a relatively new method for the real-time monitoring of chemical processes. For this purpose, electromagnetic resonances of the cavity resonator are used as input data for the reverse calculation (inversion). However, the reverse calculation algorithm is sensitive to disturbances of the input data, which produces measurement errors and tends to diverge, which leads to no measurement result at all. In this work a correction algorithm based on the Monte Carlo method is presented which ensures a convergent behavior of the reverse calculation algorithm.

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