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Determination of the Storage or Porosity Coefficient Using the Natural Logarithm Curve by Means of in Situ Measurements
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作者 Victor Rogelio Tirado Picado 《Open Journal of Applied Sciences》 CAS 2023年第5期672-684,共13页
The relevance of studying the storage coefficient variable brings with it the updating of this value in the hydraulic characteristics as part of the hydrogeological parameters applied to each country, where recommende... The relevance of studying the storage coefficient variable brings with it the updating of this value in the hydraulic characteristics as part of the hydrogeological parameters applied to each country, where recommended values for the storage coefficient to be used in hydrogeological studies are presented. And the application of a methodology adapted to the conditions of each country, is done under current conditions resulting in reference values. For this research work, an adequate methodology was sought for calculating the storage coefficient with a natural logarithm (LN) arrangement. To achieve this, first, the variables that affect the storage coefficient were identified, then the model was described with the natural logarithm (LN) arrangement, and as a third point the storage coefficient was calculated. In conclusion, in points 1 and 2 it was possible to calculate the storage coefficient from the Natural Logarithm arrangement model, with a correlation equal to R<sup>2</sup> = 0.99, and R<sup>2</sup> = 0.97 respectively, indicating that this method can be applied as long as there is free aquifer conditions and that manipulation of data alteration is not frequent. 展开更多
关键词 HYDROGEOLOGY Storage Coefficient TRANSMISSIBILITY DRAWDOWN natural logarithm
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Natural logarithm wavelength modulation spectroscopy 被引量:2
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作者 李绍民 孙利群 《Chinese Optics Letters》 SCIE EI CAS CSCD 2021年第3期58-63,共6页
Natural logarithm wavelength modulation spectroscopy(ln-WMS) is demonstrated in this Letter. Unlike the conventional wavelength modulation spectroscopy(WMS)-2 f technique, it is a linear method even for large absorban... Natural logarithm wavelength modulation spectroscopy(ln-WMS) is demonstrated in this Letter. Unlike the conventional wavelength modulation spectroscopy(WMS)-2 f technique, it is a linear method even for large absorbance, which is the core advantage of ln-WMS. The treating method used in ln-WMS is to take the natural logarithm of the transmitted intensity. In order to determine the proper demodulation phase, the η-seeking algorithm is introduced, which minimizes the absolute value of the first harmonic within the non-absorbing region. Subsequently, the second harmonic of the absorption signal is extracted by setting the demodulating phase as 2η. To illustrate the validity of ln-WMS, it was applied to water vapor experimentally. The result shows that even if the absorbance(base-e) is between 1.60 and 6.26, the linearity between ln-WMS-2 f and volume fraction is still established. For comparison, measurement with conventional WMS-2 f was also done, whose response no longer kept linearity. The η values retrieved in continuous measurements and the residuals were shown so as to evaluate the performance of the η-seeking algorithm. Time consumed by this algorithm was roughly 0.28 s per measurement. As an alternative WMS strategy, ln-WMS has a wide range of potential applications, especially where the absorbance is large or varies over a wide area. 展开更多
关键词 wavelength modulation spectroscopy natural logarithm wavelength modulation spectroscopy tunable diode laser absorption spectroscopy large absorbance
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