Relative permittivity measurements of a sand and clay soil, in situ

1975 ◽  
Author(s):  
J L Davis
Author(s):  
F. Demontoux ◽  
M. Gati ◽  
M. el Boudali ◽  
L. Villard ◽  
JP Wigneron ◽  
...  

Author(s):  
Robert W. Jobson ◽  
Frank Winchell ◽  
A.E. Picarella ◽  
Kiven C. Hill

In northeastern Oklahoma, very little is known about the transition from the Late Archaic to the Woodland period (Wyckoff and Brooks, 1983: 55). To date, most of the archeological evidence documenting this time period has been derived from sites with mixed or otherwise uncertain components. In this report, we present a preliminary description of a small rockshelter, 34RO252, which has a Late Archaic deposit stratigraphically below a Woodland era cultural deposit. These two deposits are unmixed, discrete, and are physically separated by an apparently sterile clay soil horizon. It is anticipated that the stratified cultural deposits at this site will help characterize the transition from the Late Archaic to the Early Woodland period along the Verdigris River in northeast Oklahoma. This site was first reported in April 1994 by two men who had discovered partially exposed human skeletal remains located in the rear remnant of a rockshelter at Oologah Lake in Rogers County, Oklahoma. The two men illegally excavated the remains and removed them from the site. 1 The rockshelter where the remains originated was subsequently examined by the authors and additional skeletal material was identified, in situ, in an exposed soil profile. A series of three radiocarbon assays, described below, placed the cultural deposit and the human remains within the Late Archaic-Woodland period (circa 780 B.C. to A.O. 900).2 This site is provisionally classified as corresponding to a cultural sequence that includes the old Grove C described by Purrington and Vehik.


2016 ◽  
Vol 62 (2) ◽  
pp. 129-134 ◽  
Author(s):  
Piotr Jankowski-Mihułowicz ◽  
Wojciech Lichoń ◽  
Grzegorz Pitera ◽  
Mariusz Węglarski

Abstract The complete methodology of designing T- and modified ring resonators in the UHF band are presented in the paper. On the basis of proposed algorithms, the dedicated software tool has been elaborated in order to determine material parameters of contemporary substrates. The program is implemented in the Mathcad environment and it includes the base of information on known materials used in electronic products. Also, test sample series for selected substrate materials (IS680, FR408, I-SPEED PCB ISOLA and A6-S LTCC FERRO) and operating frequencies from 1 GHz to 3 GHz are analyzed in details. The special test stand with a vector network analyzer has been applied in experiments. The obtained data of relative permittivity measurements and model calculations are described, discussed and concluded.


2008 ◽  
Vol 53 (No. 3) ◽  
pp. 79-84 ◽  
Author(s):  
J. Blahovec ◽  
J. Sobotka

Potato tuber specimens of two varieties (Nicola and Saturna) were deformed in a compression loading/unloading test. The tuber complex permittivity spectrum at frequencies 0.1–500 kHz was measured repeatedly during the deformation. The results show that both parts of relative permittivity (real and imaginary) decrease with increasing deformation and vice versa. The same trend was observed at all studied frequencies even if it was not equally strong in all cases. The permittivity plots versus frequency were similar in both the tested varieties and in different stages of deformation. The influence of tuber deformation on the permittivity values as well as the reversibility of the permittivity changes during the deformation are changed substantially at strains about 20% in comparison to strains up to 10%. The obtained results support the hypothesis that permittivity measurements can serve as an alternative indication of the internal structural changes in potato tissue during its loading.


2018 ◽  
Vol 7 (3) ◽  
pp. 195-208 ◽  
Author(s):  
Alex Mavrovic ◽  
Alexandre Roy ◽  
Alain Royer ◽  
Bilal Filali ◽  
François Boone ◽  
...  

Abstract. Decoupling the integrated microwave signal originating from soil and vegetation remains a challenge for all microwave remote sensing applications. To improve satellite and airborne microwave data products in forest environments, a precise and reliable estimation of the relative permittivity (ε=ε′-iε′′) of trees is required. We developed an open-ended coaxial probe suitable for in situ permittivity measurements of tree trunks at L-band frequencies (1–2 GHz). The probe is characterized by uncertainty ratios under 3.3 % for a broad range of relative permittivities (unitless), [2–40] for ε′ and [0.1–20] for ε′′. We quantified the complex number describing the permittivity of seven different tree species in both frozen and thawed states: black spruce, larch, red spruce, balsam fir, red pine, aspen and black cherry. Permittivity variability is substantial and can range up to 300 % for certain species. Our results show that the permittivity of wood is linked to the freeze–thaw state of vegetation and that even short winter thaw events can lead to an increase in vegetation permittivity. The open-ended coaxial probe proved to be precise enough to capture the diurnal cycle of water storage inside the trunk for the length of the growing season.


Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1972
Author(s):  
Rostislav Drochytka ◽  
Magdaléna Michalčíková

This paper addresses the influence of fluidized bed combustion fly ash (FBCA) and further liquefying additives on the formation of structure and on the resulting properties of self-compacting grouts based on clay soil. In order to give the best account of the influence of individual input materials, tests were conducted on samples without the use of fluidized bed combustion fly ash. Clay soil (Cl) and cement were used as input materials, and fluidized bed combustion fly ash (10% and 30%) and a liquefying additive (sodium carbonate 0.1%) were used as an admixture. It has been experimentally determined that the use of 10% FBCA with clay soil is most suitable for achieving the optimal spillage parameter of self-compacting grout (class SF2 (660–750 mm) and class SF3 (760–850 mm)). It was also found that fluidized bed combustion fly ash and the liquefying additive have a significant influence on the formation of the structure of the self-compacting grout and, due to their presence, the compressive strength of the samples increased up to 0.5 MPa after seven days of hardening. The reaction between 0.1% of sodium carbonate and clay soil increased the electrokinetic potential, which reduced the viscosity of the self-compacting grout. Within the research work, the verification of the developed self-compacting grout in situ was also carried out.


2011 ◽  
Vol 15 (5) ◽  
pp. 819-838
Author(s):  
Céline Andrieux ◽  
Marie Chrétien ◽  
Alain Denis ◽  
Richard Fabre ◽  
Jean-François Lataste

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