Experimental determination of bulk dielectric properties and porosity of porous asphalt and soils using GPR and a cyclic moisture variation technique

Geophysics ◽  
2006 ◽  
Vol 71 (4) ◽  
pp. K93-K102 ◽  
Author(s):  
W. L. Lai ◽  
W. F. Tsang ◽  
H. Fang ◽  
D. Xiao
Keyword(s):  
Water Saturation ◽  
Complex Refractive Index ◽  
Large Mass ◽  
Small Mass ◽  
Time Domain Reflectometry ◽  
Water Permeation ◽  
Moisture Variation ◽  
Wide Range ◽  
Test Materials ◽  
Variation Technique

This paper describes a new method for determining porosities in two porous construction and geologic materials (asphalt and soil) by using ground-penetrating radar (GPR) over a wide range of controlled degrees of water saturation [Formula: see text]. We call this method a cyclic moisture variation technique (CMVT). Freshwater is used as an enhancer or a tracer to allow GPR to easily detect and differentiate amounts of water or other moisture in these materials. The CMVT is based on measuring the changes of real permittivity [Formula: see text] and [Formula: see text] in the test materials as they transition from partially saturated states to a fully saturated state via cycles of water permeation and dewatering. This method does not disturb the test materials, as do the methods associated with traditional laboratory testing on cored samples. It also tests a large mass of in situ material, compared with the small mass tested by the conventional or electromagnetic coaxial transmission line (EMCTL) method (also known as a dielectric cell) and the time-domain reflectometry (TDR) method. Porosity values of asphalt [Formula: see text] and of soils [Formula: see text] were determined by fitting the data into the complex refractive index model (CRIM). Dielectric hysteresis of both soils and asphalt also is observable during the tests and shows that the pathways of water-ingress and water-egress processes are not identical in the plot of [Formula: see text] versus degrees of water saturation [Formula: see text].

A simple, effective‐medium model for water saturation in porous rocks

Geophysics ◽  
1995 ◽  
Vol 60 (4) ◽  
pp. 1070-1080 ◽  
Author(s):  
Charles R. Berg
Keyword(s):  
General Equation ◽  
Water Saturation ◽  
Effective Medium Theory ◽  
Complex Refractive Index ◽  
Low Frequency ◽  
Frequency Equation ◽  
Effective Medium ◽  
Porous Rocks ◽  
Rock Types ◽  
Wide Range

A general equation for water saturation is derived from effective‐medium theory. A simpler low‐frequency equation is also derived. Both equations are directly solvable for water saturation. The model should be applicable to any granular, water‐wet formation. Additional relationships are derived specifically for application to shaly sandstones, but the model should be applicable to a wide range of rock types, water conductivities, and tool frequencies. In the derivation, hydrocarbons are included in the matrix component of the equation and the combined “matrix” elements are treated as resistors in parallel. The low‐frequency equation is compared to various approaches to calculation of water saturation, such as Dual‐Water, Waxman‐Smits, and Bussian. The general equation is compared to three‐component effective medium, porosity index, and complex refractive index models (CRIM). The model is proven to work on experimental data under a wide range of frequencies and water conductivities. It is recommended that the new saturation model be used for nearly all types of electrical saturation calculation, whether the measurements are from standard resistivity tools or from dielectric tools.

Examination of moisture content variation within an operational wet deck

TAPPI Journal ◽  
2013 ◽  
Vol 12 (1) ◽  
pp. 45-50 ◽  
Author(s):  
LAURENCE SCHIMLECK ◽  
KIM LOVE-MYERS ◽  
JOE SANDERS ◽  
HEATH RAYBON ◽  
RICHARD DANIELS ◽  
...  
Keyword(s):  
Moisture Content ◽  
Southeastern United States ◽  
Forest Products ◽  
Time Domain Reflectometry ◽  
Water Application ◽  
Wood Moisture ◽  
International Paper ◽  
Content Variation ◽  
Moisture Variation

Many forest products companies in the southeastern United States store large volumes of roundwood under wet storage. Log quality depends on maintaining a high and constant wood moisture content; however, limited knowledge exists regarding moisture variation within individual logs, and within wet decks as a whole, making it impossible to recommend appropriate water application strategies. To better understand moisture variation within a wet deck, time domain reflectometry (TDR) was used to monitor the moisture variation of 30 southern pine logs over an 11-week period for a wet deck at the International Paper McBean woodyard. Three 125 mm long TDR probes were inserted into each log (before the deck was built) at 3, 4.5, and 7.5 m from the butt. The position of each log within the stack was also recorded. Mixed-effects analysis of variance (ANOVA) was used to examine moisture variation over the study period. Moisture content varied within the log, while position within the stack was generally not significant. The performance of the TDR probes was consistent throughout the study, indicating that they would be suitable for long term (e.g., 12 months) monitoring.

Ab initio calculation on the Optical Properties of AA- Stacked two dimensional Graphene, Silicene, Germanene, and Stanene

2018 ◽  
Vol 1 (1) ◽  
pp. 46-50
Author(s):  
Rita John ◽  
Benita Merlin
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Complex Refractive Index ◽  
Single Layer ◽  
Generalized Gradient ◽  
Electronic Band ◽  
Wide Range ◽  
Optical Region

In this study, we have analyzed the electronic band structure and optical properties of AA-stacked bilayer graphene and its 2D analogues and compared the results with single layers. The calculations have been done using Density Functional Theory with Generalized Gradient Approximation as exchange correlation potential as in CASTEP. The study on electronic band structure shows the splitting of valence and conduction bands. A band gap of 0.342eV in graphene and an infinitesimally small gap in other 2D materials are generated. Similar to a single layer, AA-stacked bilayer materials also exhibit excellent optical properties throughout the optical region from infrared to ultraviolet. Optical properties are studied along both parallel (||) and perpendicular ( ) polarization directions. The complex dielectric function (ε) and the complex refractive index (N) are calculated. The calculated values of ε and N enable us to analyze optical absorption, reflectivity, conductivity, and the electron loss function. Inferences from the study of optical properties are presented. In general the optical properties are found to be enhanced compared to its corresponding single layer. The further study brings out greater inferences towards their direct application in the optical industry through a wide range of the optical spectrum.

scholarly journals Resection of primary cardiac angiosarcoma infiltrating the right atrioventricular junction and tricuspid valve: a case report

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Lubna Bakr ◽  
Hussam AlKhalaf ◽  
Ahmad Takriti
Keyword(s):  
Surgical Resection ◽  
Tricuspid Valve ◽  
Right Atrium ◽  
Large Mass ◽  
Small Mass ◽  
Malignant Tumours ◽  
Atrioventricular Junction ◽  
Cardiac Angiosarcoma ◽  
Complete Surgical Resection ◽  
The Right

Abstract Background Primary cardiac tumours are extremely rare. Most of them are benign. Sarcomas account for 95% of the malignant tumours. Prognosis of primary cardiac angiosarcoma remains poor. Complete surgical resection is oftentimes hampered when there is extensive tumour involvement into important cardiac apparatus. We report a case of cardiac angiosarcoma of the right atrium and ventricle, infiltrating the right atrioventricular junction and tricuspid valve. Case presentation Initially, a 22-year-old man presented with dyspnoea. One year later, he had recurrent pericardial effusion. Afterwards, echocardiography revealed a large mass in the right atrium, expanding from the roof of the right atrium to the tricuspid valve. The mass was causing compression on the tricuspid valve, and another mass was seen in the right ventricle. Complete resection of the tumour was impossible. The mass was resected with the biggest possible margins. The right atrium was reconstructed using heterologous pericardium. The patient’s postoperative course was uneventful. Postoperative echocardiography showed a small mass remaining in the right side of the heart. Histopathology and immunohistochemistry confirmed the diagnosis of angiosarcoma. The patient underwent adjuvant chemotherapy and radiotherapy later on. He survived for 1 year and 5 days after the surgery. After a diagnosis of lung and brain metastases, he ended up on mechanical ventilation for 48 h and died. Conclusions Surgical resection combined with postoperative chemotherapy and radiotherapy is feasible even in patients with an advanced stage of cardiac angiosarcoma when it is impossible to perform complete surgical resection.

scholarly journals Measurement of unsaturated meltwater percolation flux in seasonal snowpack using self-potential

2021 ◽  
pp. 1-16
Author(s):  
Wilson S. Clayton
Keyword(s):  
Method Development ◽  
Water Saturation ◽  
Field Measurements ◽  
Time Domain Reflectometry ◽  
Electrode Spacing ◽  
Glacier Mass Balance ◽  
Wetting Front ◽  
Electrical Field Strength ◽  
Water Redistribution ◽  
Self Potential

Abstract This paper presents a feasibility study of in situ field measurements of unsaturated meltwater percolation flux within the vertical profile of a snowpack, using the self-potential (SP) method. On-site snowmelt column tests calibrated the SP measurements. The SP data measured electrical field strength with an electrode spacing of 20 cm, and coincident water saturation (Sw) measurements using time domain reflectometry allowed calculation of SP-modeled vertical percolation flux (qsp), expressed as Darcy velocity. The results reflected transient diurnal snowmelt dynamics, with peak flux lagging arrival of a saturation wetting front. Peak daily qsp was 60 to >300 mm d−1, whereas daily snowmelt was 20–50 mm w.e. Surface refreezing events appeared to cause upward flow, possibly representing water redistribution toward the freezing boundary. Calculated fluxes were comparable to actual fluxes, although average errors ranged from −15 to +46% compared to average of melt expected from surface energy-balance and ablation stake measurements. By advancing method development to measure unsaturated meltwater percolation flux in snowpacks this study creates opportunities to study fundamental snowmelt processes, may improve mathematical modeling and may supplement glacier mass-balance studies and studies of snowmelt interactions with avalanches, groundwater and surface water.

Influence of the Coagulation-Bath Temperature on Membrane Formation Mechanism and Properties of PVDF/TA-ATP Hybrid Membrane

2015 ◽  
Vol 713-715 ◽  
pp. 2723-2726
Author(s):  
Yue Rong Shi ◽  
Gui Fang Zhang ◽  
Xing Tian Liu ◽  
Xue Tao Tian ◽  
Yi Ping Zhao ◽  
...  
Keyword(s):  
Formation Mechanism ◽  
Vinylidene Fluoride ◽  
Pure Water ◽  
Water Flux ◽  
Bath Temperature ◽  
Time Domain Reflectometry ◽  
Coagulation Bath ◽  
Membrane Formation ◽  
Water Permeation ◽  
Ultrasonic Time

In this study, poly (vinylidene fluoride) (PVDF) hybrid membranes were prepared from polymeric blend of PVDF/tannic acid (TA)-Attapulgite (ATP)/PEG system via phase inversion induced by immersion precipitation in water coagulation bath. The membrane formation mechanism of PVDF/TA-ATP/PEG casting solutions in water bath thermodynamics at different temperatures and the process of membrane formation were investigated via cloud point determination and ultrasonic time-domain reflectometry (UTDR). The structures and properties of the membrane were characterized by scanning electron microscopy (SEM), and water permeation experiment, respectively. It was found that the rate of precipitation controlled by the Coagulation-Bath thermodynamics. With the coagulation temperature increasing, the gelation line was moved to non-solvent axis and the pure water flux were decreased.

Relating Acoustic Anisotropy to Kerogen Content in Unconventional Formations - A Case Study in A Kerogen-Rich Unconventional Carbonate

2021 ◽  
Author(s):  
Yair Gordin ◽  
Thomas Bradley ◽  
Yoav O. Rosenberg ◽  
Anat Canning ◽  
Yossef H. Hatzor ◽  
...  
Keyword(s):  
Wave Velocity ◽  
Water Saturation ◽  
Well Logs ◽  
Rock Properties ◽  
Thermal Maturity ◽  
Burial Diagenesis ◽  
S Wave ◽  
Velocity Anisotropy ◽  
Thermal Maturation ◽  
Wide Range

Abstract The mechanical and petrophysical behavior of organic-rich carbonates (ORC) is affected significantly by burial diagenesis and the thermal maturation of their organic matter. Therefore, establishing Rock Physics (RP) relations and appropriate models can be valuable in delineating the spatial distribution of key rock properties such as the total organic carbon (TOC), porosity, water saturation, and thermal maturity in the petroleum system. These key rock properties are of most importance to evaluate during hydrocarbon exploration and production operations when establishing a detailed subsurface model is critical. High-resolution reservoir models are typically based on the inversion of seismic data to calculate the seismic layer properties such as P- and S-wave impedances (or velocities), density, Poisson's ratio, Vp/Vs ratio, etc. If velocity anisotropy data are also available, then another layer of data can be used as input for the subsurface model leading to a better understanding of the geological section. The challenge is to establish reliable geostatistical relations between these seismic layer measurements and petrophysical/geomechanical properties using well logs and laboratory measurements. In this study, we developed RP models to predict the organic richness (TOC of 1-15 wt%), porosity (7-35 %), water saturation, and thermal maturity (Tmax of 420-435⁰C) of the organic-rich carbonate sections using well logs and laboratory core measurements derived from the Ness 5 well drilled in the Golan Basin (950-1350 m). The RP models are based primarily on the modified lower Hashin-Shtrikman bounds (MLHS) and Gassmann's fluid substitution equations. These organic-rich carbonate sections are unique in their relatively low burial diagenetic stage characterized by a wide range of porosity which decreases with depth, and thermal maturation which increases with depth (from immature up to the oil window). As confirmation of the method, the levels of organic content and maturity were confirmed using Rock-Eval pyrolysis data. Following the RP analysis, horizontal (HTI) and vertical (VTI) S-wave velocity anisotropy were analyzed using cross-dipole shear well logs (based on Stoneley waves response). It was found that anisotropy, in addition to the RP analysis, can assist in delineating the organic-rich sections, microfractures, and changes in gas saturation due to thermal maturation. Specifically, increasing thermal maturation enhances VTI and azimuthal HTI S-wave velocity anisotropies, in the ductile and brittle sections, respectively. The observed relationships are quite robust based on the high-quality laboratory and log data. However, our conclusions may be limited to the early stages of maturation and burial diagenesis, as at higher maturation and diagenesis the changes in physical properties can vary significantly.

scholarly journals Vertical differentiation of pedogenic iron forms – a key of hydromorphic soil profile development

2021 ◽  
Vol 70 (4) ◽  
pp. 369-380
Author(s):  
Marianna Ringer ◽  
◽  
Gergely Jakab ◽  
Péter Sipos ◽  
Máté Szabó ◽  
...  
Keyword(s):  
Soil Profile ◽  
Water Saturation ◽  
Vertical Position ◽  
Soil Profiles ◽  
Spatial And Temporal Patterns ◽  
Hydromorphic Soil ◽  
Annual Variations ◽  
Wide Range ◽  
The Vertical Distribution ◽  
Iron Forms

This paper focuses on the vertical distribution and characterisation of pedogenic iron forms in a Gleysol- Histosol transect developed in a marshy area in the Danube-Tisza Interfluve, Hungary. Four soil profiles were investigated along a series of increasing waterlogging and spatial and temporal patterns of hydromorphic pedofeatures (characteristics of pedogenic iron forms) were recorded. Frequent and wide-range redox potential (Eh) changes caused the emergence of many types of redoximorphic iron features, including mottles, plaques and nodules. The forms of these features depended on the micro-environments determined by the vertical position in the soil profile and the presence of plant roots. The greatest iron enrichment occurred in the zone of most intensive and widest-range redox fluctuations. Increasing water saturation resulted the extension of gleyic pattern due to the existence of permanent reduction. Most of the features also showed annual variations during the varying periods of water saturation and aeration.

scholarly journals A multi-component SIMP model with U(1)X → Z2 × Z3

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Soo-Min Choi ◽  
Jinsu Kim ◽  
Pyungwon Ko ◽  
Jinmian Li
Keyword(s):  
Dark Matter ◽  
Gauge Symmetry ◽  
Mass Difference ◽  
Massive Particle ◽  
Large Mass ◽  
Small Mass ◽  
Dark Matter Candidate ◽  
Mass Hierarchy ◽  
New Class ◽  
Matter Fields

Abstract Multi-component dark matter scenarios are studied in the model with U(1)X dark gauge symmetry that is broken into its product subgroup Z2 × Z3 á la Krauss-Wilczek mechanism. In this setup, there exist two types of dark matter fields, X and Y, distinguished by different Z2 × Z3 charges. The real and imaginary parts of the Z2-charged field, XR and XI, get different masses from the U(1)X symmetry breaking. The field Y, which is another dark matter candidate due to the unbroken Z3 symmetry, belongs to the Strongly Interacting Massive Particle (SIMP)-type dark matter. Both XI and XR may contribute to Y’s 3 → 2 annihilation processes, opening a new class of SIMP models with a local dark gauge symmetry. Depending on the mass difference between XI and XR, we have either two-component or three-component dark matter scenarios. In particular two- or three-component SIMP scenarios can be realised not only for small mass difference between X and Y, but also for large mass hierarchy between them, which is a new and unique feature of the present model. We consider both theoretical and experimental constraints, and present four case studies of the multi-component dark matter scenarios.

scholarly journals Vortex-Induced Vibration: the slower deceleration of the west bank leads to the shortening of the Humen Bridge in Guangdong, China

2020 ◽  
Author(s):  
Haili Ran ◽  
Xiaoyong Lu ◽  
Ruohan Zheng ◽  
Cui Yang ◽  
Qiuyun Liu
Keyword(s):  
Potential Energy ◽  
Civil Engineering ◽  
West Bank ◽  
Large Mass ◽  
Small Mass ◽  
The West ◽  
Vortex Induced Vibration ◽  
Gravitational Fields ◽  
The Earth ◽  
Engineering Projects

The Earth self-rotates in the solar and lunar gravitational fields. According to Newton’s Law of Inertia, large mass accelerates and decelerates more slowly than smaller masses, whereas small mass accelerates and decelerates more quickly than larger mass, which gives rise to stress when potential energy is present, damaging civil engineering projects. Humen Bridge of Guangdong, China and two century-old dams in Michigan which were affected recently can be explained by this theory.

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