scholarly journals Direct measurement of the unjacketed pore modulus of porous solids

2018 ◽  
Vol 474 (2219) ◽  
pp. 20180602 ◽  
Author(s):  
Ali Tarokh ◽  
Emmanuel Detournay ◽  
Joseph Labuz
Keyword(s):  
Stress Measurement ◽  
Pressure Change ◽  
Porous Solids ◽  
Testing System ◽  
Effective Pressure ◽  
Porous Rock ◽  
Indirect Approach ◽  
Mineral Constituent ◽  
Solid Bulk ◽  
Skempton Coefficient

Pressure decline caused by the extraction of oil from deep sedimentary layers depends on the pore modulus K pp , a poroelastic parameter that characterizes the effect of pressure change on pore volume under constant mean stress. Measurement of K pp is difficult, however, as it requires calibration to account for fluid compressibility and compliance of the testing system. Nevertheless, knowing the easily measurable drained pore modulus K p and adopting an assumption on the unjacketed pore modulus K s ″, it is possible to determine K pp because these pore moduli are related. Previous work on indirectly estimating K s ″ claimed that K s ″ is strongly dependent on Terzaghi effective pressure P′ and therefore not a constant; also, K s ″ might be different from K s , the solid bulk modulus of the major mineral constituent. We overcome the limitations of the indirect approach by directly measuring K s ″. The experiments reveal that K s ″ is indeed a constant and that for an ideal porous rock, the assumption of K s ′ ′ = K s holds. Furthermore, a constant K s ″ implies that K p and K pp are functions of Terzaghi effective pressure only. These results provide a framework to accurately determine the Skempton coefficient B .

Research on a New Stress Sensor Based on the Amorphous Alloy

2012 ◽  
Vol 241-244 ◽  
pp. 988-992
Author(s):  
Cheng Wen Liu
Keyword(s):  
Mathematical Model ◽  
Amorphous Alloy ◽  
Stress Measurement ◽  
Linear Regression Analysis ◽  
Testing System ◽  
Multivariate Linear Regression Analysis ◽  
Soft Magnetic ◽  
Alloy Material ◽  
Working Principle ◽  
The Mathematical Model

Amorphous alloy material has good soft magnetic properties, so it can be used for stress measurement. At first, the working principle of the stress measurement was analyzed. Secondly its output characteristic mathematical model was established by adopting multivariate linear regression analysis method, and the simulation of the mathematical model was made based on Matlab. Finally a practice measurement with Fe-base TM—M Amorphous alloy was completed. The results of the test have showed that the stress measurement method has some characteristics of being sensitiveness to measure and simple to make a testing system, and a promising method of measuring stress.

Sealing performance test for V-insert clamp applicable to automobile exhaust pipes

2013 ◽  
Vol 227 (10) ◽  
pp. 2228-2235 ◽  
Author(s):  
Sung Ho Yoon ◽  
Young Eun Hwang
Keyword(s):  
Performance Test ◽  
Gradual Increase ◽  
Applied Pressure ◽  
Pressure Change ◽  
Testing System ◽  
Clamping Force ◽  
Automobile Exhaust ◽  
Sealing Performance ◽  
Applied Torque ◽  
Test Increase

The sealing performance of V-insert clamp used in automobile exhaust pipes was examined for various applied torques by a specially designed pneumatic testing system. Axial clamping forces of V-insert clamp were evaluated through a clamping performance test. In the clamping performance test, increase in the torque showed gradual increase in the axial clamping force for all gaps between exhaust pipes that were considered. Slight increase in the torque resulted in relatively high axial clamping force. In the sealing performance test, when applied pressure was 50 kPa, the leak was not present in all applied torques due to no pressure change as a function of time. For 100 kPa, the leak was observed for applied torques of 3 N-m and lower. When V-insert clamp was used to join the pipes together, at least the applied torque of 4 N-m was needed in order for V-insert clamp to effectively function in the exhaustion system. Therefore, it can be concluded that V-insert clamp showed sufficient sealing performance to support the applied pressure of up to 100 kPa within the exhaustion system when relatively high torque was applied.

Initial validations of an indirect approach for measuring emotions

2007 ◽  
Author(s):  
Josh Davis ◽  
Amanda D. Angie ◽  
Mary Shane Connelly ◽  
Greg Ruark ◽  
Jason H. Hill
Keyword(s):  
Indirect Approach

Guiding Principles for Team Stress Measurement

2012 ◽  
Author(s):  
Aaron S. Dietz ◽  
Mary Jane Sierra ◽  
Kimberly Smith-Jentsch ◽  
Eduardo Salas
Keyword(s):  
Stress Measurement ◽  
Guiding Principles

Comparison of Examinees’ and Doctors’ Judgement of Health Status Using Data in an AMHTS

1984 ◽  
Vol 23 (01) ◽  
pp. 15-22
Author(s):  
Y. Sekita ◽  
T. Ohta ◽  
M. Inoue ◽  
H. Takeda
Keyword(s):  
Health Status ◽  
Discriminant Analysis ◽  
Explanatory Power ◽  
Laboratory Data ◽  
Subjective Symptom ◽  
Health Conditions ◽  
Testing System ◽  
Multiple Discriminant Analysis ◽  
Canonical Axis ◽  
Using Data

SummaryJudgements of examinees’ health status by doctors and by the examinees themselves are compared applying multiple discriminant analysis. The doctors’ judgements of the examinees’ health status are studied comparatively using laboratory data and the examinees’ subjective symptom data.This data was obtained in an Automated Multiphasic Health Testing System. We discuss the health conditions which are significant for the judgement of doctors about the examinees. The results show that the explanatory power, when using subjective symptom data, is fair in the case of the doctors’ judgement. We found common variables, such as nervousness, lack of perseverance etc., which form the first canonical axis.

Heart Rate Signal Decomposition

2000 ◽  
Vol 39 (02) ◽  
pp. 200-203
Author(s):  
H. Mizuta ◽  
K. Yana
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Pressure Change ◽  
Normal Subjects ◽  
Signal Decomposition ◽  
Large Individual ◽  
Heart Rate Fluctuations ◽  
Type Pattern ◽  
Signal Cancellation ◽  
Pressure Changes

Abstract:This paper proposes a method for decomposing heart rate fluctuations into background, respiratory and blood pressure oriented fluctuations. A signal cancellation scheme using the adaptive RLS algorithm has been introduced for canceling respiration and blood pressure oriented changes in the heart rate fluctuations. The computer simulation confirmed the validity of the proposed method. Then, heart rate fluctuations, instantaneous lung volume and blood pressure changes are simultaneously recorded from eight normal subjects aged 20-24 years. It was shown that after signal decomposition, the power spectrum of the heart rate showed a consistent monotonic 1/fa type pattern. The proposed method enables a clear interpretation of heart rate spectrum removing uncertain large individual variations due to the respiration and blood pressure change.

The methodological approach for the determination of the pressure of artificial raindrops as a question of the theory of splash soil erosion

2020 ◽  
pp. 24-28
Author(s):  
Mihail Zver'kov
Keyword(s):  
Block Diagram ◽  
Methodological Approach ◽  
Control Measures ◽  
Soil Conditions ◽  
Effective Pressure ◽  
Long Distance ◽  
Splash Erosion ◽  
Rain Drops ◽  
Artificial Rain ◽  
The Impact

To the article the results of the theoretical and experimental researches are given on questions of estimates of the dynamic rate effect of raindrop impact on soil. The aim of this work was to analyze the current methods to determine the rate of artificial rain pressure on the soil for the assessment of splash erosion. There are the developed author’s method for calculation the pressure of artificial rain on the soil and the assessment of splash erosion. The study aims to the justification of evaluation methods and the obtaining of quantitative characteristics, prevention and elimination of accelerated (anthropogenic) erosion, the creation and the realization of the required erosion control measures. The paper considers the question of determining the pressure of artificial rain on the soil. At the moment of raindrops impact, there is the tension in the soil, which is called vertical effective pressure. It is noted that the impact of rain drops in the soil there are stresses called vertical effective pressure. The equation for calculation of vertical effective pressure is proposed in this study using the known spectrum of raindrops. Effective pressure was 1.4 Pa for the artificial rain by sprinkler machine «Fregat» and 5.9 Pa for long distance sprinkler DD-30. The article deals with a block diagram of the sequence for determining the effective pressure of rain drops on the soil. This diagram was created by the author’s method of calculation of the effective pressure of rain drops on the soil. The need for an integrated approach to the description of the artificial rain impact on the soil is noted. Various parameters characterizing drop erosion are considered. There are data about the mass of splashed soil in the irrigation of various irrigation machinery and installations. For example, the rate (mass) of splashed soil was 0.28…0.78 t/ha under irrigation sprinkler apparatus RACO 4260–55/701C in the conditions of the Ryazan region. The method allows examining the environmental impact of sprinkler techniques for analyzes of the pressure, caused by raindrops, on the soil. It can also be useful in determining the irrigation rate before the runoff for different types of sprinkler equipment and soil conditions.

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