scholarly journals A procedure for in situ wind load reconstruction from structural response only based on field testing data

Author(s):  
A. Kazemi Amiri ◽  
C. Bucher
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hailin Zhang ◽  
João Antonangelo ◽  
Chad Penn

AbstractPortable X-ray fluorescence (pXRF) spectrometer allows fast in-situ elemental determination without wet digestion for soils or geological materials, but the use of XRF on wet materials is not well documented. Our objective was to develop a rapid field method using pXRF to measure metals in the residues from horizontal directional drilling (HDD) operations so that proper disposal decisions can be made in-situ. To establish the procedure, we spiked soil samples with 4 concentrations of Cr, Ni, Cu, Zn, As, Cd, and Pb up to 1000 mg kg−1, and then the metal concentrations were determined by wet chemical method after drying and acid digestion (standard method), and by pXRF, also at laboratory conditions, after drying and at two different moisture conditions. The measurements by pXRF and standard method after drying and after removal of excess water (AREW) were highly correlated with slopes ranging from 0.83 ± 0.01 to 1.08 ± 0.01 (P < 0.001) for all metals. The relationship was better AREW than the saturated paste without removal of excess water and the moisture content affected only the accuracy of As, Cd, and Pb. The procedure established was successfully used for HDD residues collected from 26 states of US with moisture content ranging from 14 to 83% AREW. The pXRF was proven to be a reliable tool for fast detection of common metals in dried soils and HDD residues, and samples containing < 30% moisture content without needing to correct for moisture. If the moisture is > 30%, excess water in samples need to be removed with a commercially available filter press to achieve high accuracy. The developed procedures reduce time of metal detection from days to about an hour which allows drilling operators to make quick decisions on soil or HDD disposal.


Author(s):  
Jeffrey L. Walters

Wide ranging viscosities in ultrasonic flow measurement for liquids is a common pipeline scenario. With ever maturing oil fields and the growth in oilsands production, the trend appears to be towards the higher end viscosities and/or novel approaches towards reducing the viscosities for transportation such as heating. The variable viscosities of the fluids provide some unique challenges to ultrasonic flowmeters not only in terms of flow profile modeling, but also in acoustic signal propagation and application to elevated temperature fluids which likewise affect the accuracy or performance of the measurement. The flow profile interrogation techniques will be discussed with an emphasis on a distributed chord model together with the use of a waveguide technology that minimizes acoustic and fluid temperature effects. A combination of R&D, calibration and field testing data will both demonstrate these challenges as well as show the increased performance that results from the application of these approaches.


Author(s):  
A Colombo ◽  
L Meneghetti ◽  
R Teixeira ◽  
T Bittencourt

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5102
Author(s):  
Yu Hu ◽  
Jian Yang ◽  
Charalampos Baniotopoulos

Offshore wind energy is a rapidly maturing renewable energy technology that is poised to play an important role in future energy systems. The respective advances refer among others to the monopile foundation that is frequently used to support wind turbines in the marine environment. In the present research paper, the structural response of tall wind energy converters with various stiffening schemes is studied during the erection phase as the latter are manufactured in modules that are assembled in situ. Rings, vertical stiffeners, T-shaped stiffeners and orthogonal stiffeners are considered efficient stiffening schemes to strengthen the tower structures. The loading bearing capacity of offshore monopile wind turbine towers with the four types of stiffeners were modeled numerically by means of finite elements. Applying a nonlinear buckling analysis, the ultimate bearing capacity of wind turbine towers with four standard stiffening schemes were compared in order to obtain the optimum stiffening option.


Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2864 ◽  
Author(s):  
Frederico G. Alabarse ◽  
Boby Joseph ◽  
Andrea Lausi ◽  
Julien Haines

The incorporation of guest species in zeolites has been found to strongly modify their mechanical behavior and their stability with respect to amorphization at high pressure (HP). Here we report the strong effect of H2O on the pressure-induced amorphization (PIA) in hydrated AlPO4-17. The material was investigated in-situ at HP by synchrotron X-ray powder diffraction in diamond anvil cells by using non- and penetrating pressure transmitting media (PTM), respectively, silicone oil and H2O. Surprisingly, in non-penetrating PTM, its structural response to pressure was similar to its anhydrous phase at lower pressures up to ~1.4 GPa, when the amorphization was observed to start. Compression of the structure of AlPO4-17 is reduced by an order of magnitude when the material is compressed in H2O, in which amorphization begins in a similar pressure range as in non-penetrating PTM. The complete and irreversible amorphization was observed at ~9.0 and ~18.7 GPa, respectively, in non- and penetrating PTM. The present results show that the insertion of guest species can be used to strongly modify the stability of microporous material with respect to PIA, by up to an order of magnitude.


2020 ◽  
Vol 22 (39) ◽  
pp. 22260-22270
Author(s):  
Henrike Schmies ◽  
Arno Bergmann ◽  
Elisabeth Hornberger ◽  
Jakub Drnec ◽  
Guanxiong Wang ◽  
...  

Investigations on the (electronic) structure of carbon- and oxide-supported Pt nanoparticles during electrochemical oxidation via in situ X-ray diffraction, absorption spectroscopy and the Pt dissolution rate by in situ mass spectrometry.


2011 ◽  
Vol 90-93 ◽  
pp. 1412-1418
Author(s):  
Jiang Hua Shi ◽  
Zhen Zhong Cao ◽  
Zhao Yan Li ◽  
Xiao Ming Yuan ◽  
Lin Dong

Based on liquefaction survey of 2003 Xinjiang Bachu earthquake of Ms6.8 and in-situ shear wave velocity testing data, the feasibility and applicability of five typical liquefaction evaluation methods which use shear wave velocities as criteria are presented herein. Analysis showed that none of the five liquefaction evaluation methods can provide a satisfactory result in Bachu area. The successful judging rates are only 36% to 64%. The intensity method which is employed to evaluate liquefied and non-liquefied sites in Bachu area provides only 40% successful judging rate, and the method is risky in intensity VII area and conservative in intensity IX area. The critical lines of the five methods deviate greatly from the actual lines. In intensity VII area all the five methods incorrectly misjudge. Further work has to be conducted to research on the soil properties in Bachu area and to establish the regional liquefaction evaluation method in Xinjiang.


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