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Quantitative modeling of rock electrical resistivity under uniaxial loading and unloading

Qu Chuanqi, Yiguo Xue, Su Maoxin, Qiu Daohong, Ma Xiaoyin, Liu Qiushi, Li Guangkun

Acta Geophysica

2024

Vol. 72, no. 1

195--212

In geotechnical engineering practice, studying the characteristics of rock electrical resistivity under different physical and mechanical environments is important for improving the accuracy of unfavorable geological condition detection. In this study, Dali marble and granite were subjected to cyclic loading and unloading at different peak pressures, and the electrical resistivity of the core samples was continuously monitored. The aim was to derive the electrical resistivity variation patterns of two rocks under cyclic loading and unloading. Then, the theoretical models of electrical resistivity for the two rocks were established through theoretical derivation, and the model equations were consistent with the experimental findings. Finally, a MATLAB program was used for nonlinear fitting of the unloading phase electrical resistivity variation patterns of the rocks to reveal the quantified pressure-electrical resistivity patterns of the two rocks with different lithologies. Based on this, well-performing rock pressure-electrical resistivity relationship models were developed with three parameters: pressure, water content and electrical resistivity. The experimental results can significantly improve the accuracy of stratigraphic state inversion and unfavorable body boundary identification by providing realistic electrical resistivity constraints for electrical resistivity tomography.

Przegląd zastosowań spektroskopii w zakresie bliskiej podczerwieni w analizie wilgotności śladowej w produktach leczniczych weterynaryjnych immunologicznych

Bulenger K., Biernacki B., Krasucka D. M., Szumiło J., Cuvelier B.

Wiadomości Chemiczne

2016

[Z] 70, 11-12

747--759

However, the infrared radiation has been discovered more than 200 years ago, near-infrared spectroscopy (NIRS), as a useful method, was recognized in the 1960s. Currently, under the influence of technological development, quantitative and qualitative methods require short time and precision of measurements. NIRS has a growing recognition in the industry, particularly pharmaceutical where each component of the finished product has impact on the quality and safety of the product. Freeze-dried immunological veterinary medicinal products (IVMPs), despite high specificity, contain not too complicated matrices for analysis. Karl Fischer titration is routinely used as accurate and effective method to determine the water content in the IVMPs, but the use of near-infrared spectroscopy allows to avoid the adverse impact of environmental factors on the measurements. However, for NIRS, there is a need to create a calibration model which will be precise for high diversity of samples. The most important is the optimization of the model by eliminating the factors that might influence the measurement of water content. Quantification methods most frequently used are: MLR, PLS and PCR, which are preceded by the appropriate pretreatments (derivatives of Savitzky Golay).

Reaction System Models for the Heat Shock Response

Azimi S., Iancu B., Petre I.

Fundamenta Informaticae

2014

Vol. 131, nr 3-4

299--312

Reaction systems are a formal framework for modeling processes driven by biochemical reactions. They are based on the mechanisms of facilitation and inhibition. A main assumption is that if a resource is available, then it is present in sufficient amounts and as such, several reactions using the same resource will not compete concurrently against each other; this makes reaction systems very different as a modeling framework than traditional frameworks such as ODEs or continuous time Markov chains. We demonstrate in this paper that reaction systems are rich enough to capture the essential characteristics of ODE-based models. We construct a reaction system model for the heat shock response in such a way that its qualitative behavior correlates well with the quantitative behavior of the corresponding ODE model. We construct our reaction system model based on a novel concept of dominance graph that captures the competition on resources in the ODE model. We conclude with a discussion on the expressivity of reaction systems as compared to that of ODE-based models.