Computation of local permeability in granular soils using spatial time domain reflectometer

2022 ◽  
Vol 12 (1) ◽  
pp. 1-26
Author(s):  
V. S. R. Annapareddy ◽  
T. Bore ◽  
M. Bajodek ◽  
A. Scheuermann
Keyword(s):  
Time Domain ◽  
Particle Diameter ◽  
Time Domain Reflectometry ◽  
Particle Migration ◽  
Granular Soils ◽  
Practical Applications ◽  
Effective Particle ◽  
Local Permeability ◽  
Order Of Magnitude ◽  
Time Domain Reflectometer

This letter proposes semi-analytical methods to obtain the local permeability for granular soils based on indirect measurements of the local porosity profile in a large coaxial cell permeameter using spatial time domain reflectometry. The porosity profile is used to obtain the local permeability using the modified Kozeny-Carman and Katz-Thompson equations, which incorporated an effective particle diameter that accounted for particle migration within the permeameter. The profiles of the local permeability obtained from the proposed methods are compared with experimentally obtained permeability distributions using pressure measurements and flow rate. The permeabilities obtained with the proposed methods are comparable with the experimentally obtained permeabilities and are within one order of magnitude deviation, which is an acceptable range for practical applications.

scholarly journals Locating the frozen–unfrozen interface in soils using time-domain reflectometry

1982 ◽  
Vol 19 (4) ◽  
pp. 511-517 ◽  
Author(s):  
T. H. W. Baker ◽  
J. L. Davis ◽  
H. N. Hayhoe ◽  
G. C. Topp
Keyword(s):  
Transmission Lines ◽  
Time Domain ◽  
Freezing Temperature ◽  
Time Domain Reflectometry ◽  
Temperature Measurements ◽  
Soil Freezing ◽  
Electromagnetic Pulses ◽  
The Time Domain ◽  
Time Domain Reflectometer ◽  
Liquid And Solid Phases

The time-domain reflectometry technique was compared with the temperature measurement method for locating the frozen–unfrozen interface in water and sandy soils. This technique depends on the high-frequency (1–1000 MHz) electrical properties of water that change significantly and abruptly between the liquid and solid phases. Parallel wire transmission lines were inserted into the soil to guide electromagnetic pulses produced by a time-domain reflectometer (TDR). The frozen–unfrozen interface produced reflections measured by the TDR which were in turn used to locate the interface as it moved along the transmission line. In the laboratory it was possible to locate the interface using the TDR to within ±0.5 cm and in the field to within ±2.4 cm. These errors were equal to those associated with the temperature measurements. Keywords: soil freezing, temperature measurements, dielectric constant, time-domain reflectometry.

Diagnostics of metal samples using the results of experimental and theoretical study of positively charged microparticles formed upon sample destruction

2018 ◽  
Vol 84 (10) ◽  
pp. 23-28
Author(s):  
D. A. Golentsov ◽  
A. G. Gulin ◽  
Vladimir A. Likhter ◽  
K. E. Ulybyshev
Keyword(s):  
Experimental Data ◽  
Early Stage ◽  
Experimental Studies ◽  
Material Model ◽  
Total Charge ◽  
Cross Sectional ◽  
Practical Applications ◽  
Mechanical And Electrical Properties ◽  
Order Of Magnitude ◽  
Using Data

Destruction of bodies is accompanied by formation of both large and microscopic fragments. Numerous experiments on the rupture of different samples show that those fragments carry a positive electric charge. his phenomenon is of interest from the viewpoint of its potential application to contactless diagnostics of the early stage of destruction of the elements in various technical devices. However, the lack of understanding the nature of this phenomenon restricts the possibility of its practical applications. Experimental studies were carried out using an apparatus that allowed direct measurements of the total charge of the microparticles formed upon sample rupture and determination of their size and quantity. The results of rupture tests of duralumin and electrical steel showed that the size of microparticles is several tens of microns, the particle charge per particle is on the order of 10–14 C, and their amount can be estimated as the ratio of the cross-sectional area of the sample at the point of discontinuity to the square of the microparticle size. A model of charge formation on the microparticles is developed proceeding from the experimental data and current concept of the electron gas in metals. The model makes it possible to determine the charge of the microparticle using data on the particle size and mechanical and electrical properties of the material. Model estimates of the total charge of particles show order-of-magnitude agreement with the experimental data.

Advanced Non-Destructive Fault Isolation Techniques for PCB Substrates Using Magnetic Current Imaging and Terahertz Time Domain Reflectometry

2018 ◽  
Author(s):  
Daechul Choi ◽  
Yoonseong Kim ◽  
Jongyun Kim ◽  
Han Kim
Keyword(s):  
Time Domain ◽  
Quantum Interference ◽  
Flip Chip ◽  
Imaging System ◽  
Time Domain Reflectometry ◽  
Fault Isolation ◽  
Magnetic Current ◽  
Isolation Techniques ◽  
Super Conducting ◽  
Non Destructive

Abstract In this paper, we demonstrate cases for actual short and open failures in FCB (Flip Chip Bonding) substrates by using novel non-destructive techniques, known as SSM (Scanning Super-conducting Quantum Interference Device Microscopy) and Terahertz TDR (Time Domain Reflectometry) which is able to pinpoint failure locations. In addition, the defect location and accuracy is verified by a NIR (Near Infra-red) imaging system which is also one of the commonly used non-destructive failure analysis tools, and good agreement was made.

Super-Conducting Quantum Interference Device Technique: 3-D Localization of a Short within a Flip Chip Assembly

2001 ◽  
Author(s):  
Kendall Scott Wills ◽  
Omar Diaz de Leon ◽  
Kartik Ramanujachar ◽  
Charles P. Todd
Keyword(s):  
Form Factor ◽  
Failure Analysis ◽  
Time Domain ◽  
Quantum Interference ◽  
Flip Chip ◽  
Time Domain Reflectometry ◽  
Interfacial Region ◽  
Precise Localization ◽  
Super Conducting ◽  
Accuracy Of Measurement

Abstract In the current generations of devices the die and its package are closely integrated to achieve desired performance and form factor. As a result, localization of continuity failures to either the die or the package is a challenging step in failure analysis of such devices. Time Domain Reflectometry [1] (TDR) is used to localize continuity failures. However the accuracy of measurement with TDR is inadequate for effective localization of the failsite. Additionally, this technique does not provide direct 3-Dimenstional information about the location of the defect. Super-conducting Quantum Interference Device (SQUID) Microscope is useful in localizing shorts in packages [2]. SQUID microscope can localize defects to within 5um in the X and Y directions and 35um in the Z direction. This accuracy is valuable in precise localization of the failsite within the die, package or the interfacial region in flipchip assemblies.

Failure Analysis of Broken Stitch Bonds in TSSOP Packages Using Scanning Acoustic Microscopy (SAM) and Time Domain Reflectometry (TDR)

2004 ◽  
Author(s):  
Bilal Abd-AlRahman ◽  
Corey Lewis ◽  
Todd Simons
Keyword(s):  
Failure Analysis ◽  
Mechanical Stress ◽  
Time Domain ◽  
Open Circuit ◽  
Time Domain Reflectometry ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
Root Cause ◽  
Analysis Application

Abstract A failure analysis application utilizing scanning acoustic microscopy (SAM) and time domain reflectometry (TDR) for failure analysis has been developed to isolate broken stitch bonds in thin shrink small outline package (TSSOP) devices. Open circuit failures have occurred in this package due to excessive bending of the leads during assembly. The tools and their specific application to this technique as well as the limitations of C-SAM, TDR and radiographic analyses are discussed. By coupling C-SAM and TDR, a failure analyst can confidently determine whether the cause of an open circuit in a TSSOP package is located at the stitch bond. The root cause of the failure was determined to be abnormal mechanical stress placed on the pins during the lead forming operation. While C-SAM and TDR had proven useful in the analysis of TSSOP packages, it can potentially be expanded to other wire-bonded packages.

Time Domain Reflectometry Technique for Failure Analysis

2004 ◽  
Author(s):  
Teoh King Long ◽  
Ko Yin Fern
Keyword(s):  
Failure Analysis ◽  
Time Domain ◽  
Time Domain Reflectometry ◽  
Fault Isolation ◽  
Reference Plane ◽  
First Case ◽  
Main Emphasis ◽  
Plastic Ball ◽  
Solder Balls ◽  
Non Destructive

Abstract In time domain reflectometry (TDR), the main emphasis lies on the reflected waveform. Poor probing contact is one of the common problems in getting an accurate waveform. TDR probe normalization is essential before measuring any TDR waveforms. The advantages of normalization include removal of test setup errors in the original test pulse and the establishment of a measurement reference plane. This article presents two case histories. The first case is about a Plastic Ball Grid Array package consisting of 352 solder balls where the open failure mode was encountered at various terminals after reliability assessment. In the second, a three-digit display LED suspected of an electrical short failure was analyzed using TDR as a fault isolation tool. TDR has been successfully used to perform non-destructive fault isolation in assisting the routine failure analysis of open and short failure. It is shown to be accurate and reduces the time needed to identify fault locations.

Advanced Fault Isolation Technique Using Electro-Optical Terahertz Pulse Reflectometry (EOTPR) for 2D and 2.5D Flip-Chip Package

2012 ◽  
Author(s):  
Lihong Cao ◽  
Manasa Venkata ◽  
Meng Yeow Tay ◽  
Wen Qiu ◽  
J. Alton ◽  
...  
Keyword(s):  
Time Domain ◽  
Flip Chip ◽  
Time Domain Reflectometry ◽  
Fault Isolation ◽  
Experimental Results ◽  
Terahertz Pulse ◽  
Isolation And Identification ◽  
Isolation Technique ◽  
Non Destructive

Abstract Electro-optical terahertz pulse reflectometry (EOTPR) was introduced last year to isolate faults in advanced IC packages. The EOTPR system provides 10μm accuracy that can be used to non-destructively localize a package-level failure. In this paper, an EOTPR system is used for non-destructive fault isolation and identification for both 2D and 2.5D with TSV structure of flip-chip packages. The experimental results demonstrate higher accuracy of the EOTPR system in determining the distance to defect compared to the traditional time-domain reflectometry (TDR) systems.

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