scholarly journals Investigational methods for the modeling of infiltration process in the soil and the estimating the soil hydrodynamic parameters

2019 ◽  
Vol 286 ◽  
pp. 06002
Author(s):  
M. Hachimi ◽  
A. Maslouhi ◽  
K. Tamoh ◽  
H. Qanza

Unsaturated zone in the soil generally plays an important role in the transfer of water and pollutants in the underground environment. In this context, the determination of the hydrodynamic parameters constitutes an essential step for any study of transfers of water and solutes in the unsaturated zone. The purpose of this article is the estimation the soil hydrodynamic parameters by the direct method and the inverse method, from the infiltration data by using the disc infiltrometer in the soil the basin Loukkos located in northern Morocco. Our results the numerical modeling reproduced correctly the experimental measurements. These results show that the inverse method remains a robust and accurate method for determining the soil hydrodynamic parameters compared to other conventional methods.

Author(s):  
K. Chowdhury ◽  
S. Ghosh ◽  
M. Mukherjee

AbstractThe direct method program SAYTAN has been applied successfully to redetermine the structure of cytochrome c


2019 ◽  
Vol 15 (6) ◽  
pp. 568-573
Author(s):  
Soheil Sedaghat ◽  
Ommoleila Molavi ◽  
Akram Faridi ◽  
Ali Shayanfar ◽  
Mohammad Reza Rashidi

Background: Signal transducer and activator of transcription 3 (STAT3), an oncogenic protein found constitutively active in many types of human malignancies, is considered to be a promising target for cancer therapy. Objective: In this study for the first time, a simple and accurate method has been developed for the determination of a STAT3 dimerization inhibitor called stattic in aqueous and plasma samples. Methods: A reverse-phase high-performance liquid chromatography (RP-HPLC) composed of C18 column as stationary phase, and the mixture of acetonitrile (60%) and water (40%) as mobile phase with a UV detection at 215 nm were applied for quantification of stattic. The developed method was validated by Food and Drug Administration (FDA) guideline. Results: The method provided a linear range between 1-40 and 2.5-40 µg mL-1 for aqueous and plasma samples, respectively, with a correlation coefficient of 0.999. The accuracy (as recovery) of the developed method was found to be between 95-105% for aqueous medium and 85-115% for plasma samples. The precision (as relative standard deviation) for aqueous and plasma samples was less than 6% and 15%, respectively. The sensitivity of the developed method based on FDA guideline was 1 µg mL-1 for aqueous and 2.5 µg mL-1 for plasma samples. Conclusion: These results show that the established method is a fast and accurate quantification for stattic in aqueous and plasma samples.


2020 ◽  
Vol 12 ◽  
Author(s):  
S.V. Kontomaris ◽  
A. Malamou ◽  
A. Stylianou

Background: The determination of the mechanical properties of biological samples using Atomic Force Microscopy (AFM) at the nanoscale is usually performed using basic models arising from the contact mechanics theory. In particular, the Hertz model is the most frequently used theoretical tool for data processing. However, the Hertz model requires several assumptions such as homogeneous and isotropic samples and indenters with perfectly spherical or conical shapes. As it is widely known, none of these requirements are 100 % fulfilled for the case of indentation experiments at the nanoscale. As a result, significant errors arise in the Young’s modulus calculation. At the same time, an analytical model that could account complexities of soft biomaterials, such as nonlinear behavior, anisotropy, and heterogeneity, may be far-reaching. In addition, this hypothetical model would be ‘too difficult’ to be applied in real clinical activities since it would require very heavy workload and highly specialized personnel. Objective: In this paper a simple solution is provided to the aforementioned dead-end. A new approach is introduced in order to provide a simple and accurate method for the mechanical characterization at the nanoscale. Method: The ratio of the work done by the indenter on the sample of interest to the work done by the indenter on a reference sample is introduced as a new physical quantity that does not require homogeneous, isotropic samples or perfect indenters. Results: The proposed approach, not only provides an accurate solution from a physical perspective but also a simpler solution which does not require activities such as the determination of the cantilever’s spring constant and the dimensions of the AFM tip. Conclusion: The proposed, by this opinion paper, solution aims to provide a significant opportunity to overcome the existing limitations provided by Hertzian mechanics and apply AFM techniques in real clinical activities.


2021 ◽  
Vol 13 (3) ◽  
pp. 1232
Author(s):  
Natalie Szeligova ◽  
Marek Teichmann ◽  
Frantisek Kuda

The subject of the work is the research on relevant factors influencing participation in the success of brownfield revitalization, especially in the territory of small municipalities. Research has so far dealt with the issue of determining disparities in the municipalities of the Czech Republic, not excluding small municipalities, but their subsequent application has usually been presented in larger cities. The focus on smaller municipalities or cities was usually addressed only in general. The introduction provides an overview of theoretical knowledge in the field of brownfield revitalization. Defining the level of knowledge of the monitored issues is an essential step for the purposes of more effective determination of disparities. Disparities will be determined on the basis of information on localities that have been successfully revitalized. The identified disparities are then monitored in the territory of small municipalities. For the purposes of processing, it was determined that a small municipality or city is an area with a maximum of 5000 inhabitants. Using appropriately selected statistical methods, an overview of disparities and their weights is determined, which significantly affect the success of revitalization. In small municipalities, the issue of brownfields is not emphasized but, in terms of maintaining community strength and reducing population turnover, the reuse of brownfields is a crucial theme.


2004 ◽  
Vol 182 (1) ◽  
pp. 112-116 ◽  
Author(s):  
Hua Wei ◽  
Xiaofeng Sun ◽  
Qi Zheng ◽  
Guichen Hou ◽  
Hengrong Guan ◽  
...  

2012 ◽  
Vol 2012 ◽  
pp. 1-25 ◽  
Author(s):  
S. L. Han ◽  
Takeshi Kinoshita

The determination of an external force is a very important task for the purpose of control, monitoring, and analysis of damages on structural system. This paper studies a stochastic inverse method that can be used for determining external forces acting on a nonlinear vibrating system. For the purpose of estimation, a stochastic inverse function is formulated to link an unknown external force to an observable quantity. The external force is then estimated from measurements of dynamic responses through the formulated stochastic inverse model. The applicability of the proposed method was verified with numerical examples and laboratory tests concerning the wave-structure interaction problem. The results showed that the proposed method is reliable to estimate the external force acting on a nonlinear system.


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