Initial Development of a High-frequency EMI Sensor for Detection of Subsurface Intermediate Electrically Conductive (IEC) Targets

2017 ◽  
Vol 22 (2) ◽  
pp. 111-120 ◽  
Author(s):  
Janet E. Simms ◽  
John B. Sigman ◽  
Benjamin E. Barrowes ◽  
Hollis H. Bennett ◽  
Donald E. Yule ◽  
...  
Keyword(s):  
High Frequency ◽  
Electrically Conductive ◽  
Initial Development ◽  
Emi Sensor

Exploring the lexical profile of young CLIL learners

2014 ◽  
Vol 2 (1) ◽  
pp. 53-73 ◽  
Author(s):  
María del Pilar Agustín Llach
Keyword(s):  
High Frequency ◽  
Foreign Languages ◽  
Lexical Development ◽  
Initial Development ◽  
Young Learners ◽  
L1 Influence ◽  
Oral Approach ◽  
Lexical Competence ◽  
Written Assignments ◽  
Positive Effect

This paper presents an analysis of the lexical profile of the written assignments completed by a group of young CLIL learners. Participants in the study were attending 4th grade of Primary and had received around 714 hours of exposure to English. Results revealed lexical profiles which are characteristic of young learners of foreign languages with high frequency words being the most common. We also observed that learners show frequent instances of phonetic rendering, but little L1 influence for borrowings and relexifications. This can be a sign of the typical oral approach in CLIL classrooms. The young age, low proficiency, and short CLIL experience of the learners are taken into account in the interpretation of the findings. CLIL instruction revealed a positive effect on the initial development of lexical competence. The paper closes with a section that includes some suggestions for how to enhance lexical development within CLIL tuition.

Electrically Conductive Photopatternable Silver Paste for High-Frequency Ring Resonator and Band-Pass Filter

2016 ◽  
Vol 46 (2) ◽  
pp. 1307-1318 ◽  
Author(s):  
Govind Umarji ◽  
Nilam Qureshi ◽  
Suresh Gosavi ◽  
Uttam Mulik ◽  
Atul Kulkarni ◽  
...  
Keyword(s):  
High Frequency ◽  
Ring Resonator ◽  
Band Pass Filter ◽  
Electrically Conductive ◽  
Pass Filter ◽  
Silver Paste ◽  
Band Pass

scholarly journals Impedance Spectroscopy (BeO+TiO2)-Ceramics with Additive of TiO2 Nanoparticles

2019 ◽  
pp. 366-380
Author(s):  
Anatoliy A. Lepeshev ◽  
Alexandr V. Pavlov ◽  
Nikolai A. Drokin
Keyword(s):  
Impedance Spectroscopy ◽  
High Frequency ◽  
Microwave Field ◽  
Frequency Range ◽  
Nanocrystalline Tio2 ◽  
Electrically Conductive ◽  
Dielectric Characteristics ◽  
Ceramic Samples ◽  
Static Resistance ◽  
First Time

The present study is aimed at obtaining electrically conductive two-component ceramics based on BeO with the addition of micro and nanocrystalline TiO2 powder. The ceramics of the composition (BeO+TiO2) is used in radio-electronic equipment as effective absorbers of microwave radiation and in other areas of modern electronics. The nature of the appearance of electrical conductivity and absorption of the microwave field in (BeO+TiO2) ceramics has not been completely established. The impedance spectroscopy method for the first time investigated the electrical and dielectric characteristics of this ceramics in the frequency range from 100 Hz to 100 MHz, depending on the presence of micro and nano-sized TiO2 phases in the composition of the BeO ceramics. It was established that the static resistance of ceramics with the addition of titanium oxide nanopowder is significantly reduced compared with the resistance of the original ceramics with TiO2 micropowder. It is shown that the real and imaginary components of the dielectric constant of the studied ceramics increase to abnormally large values when the frequency of the effective electric field decreases, and in the high frequency range f ≥ 108 Hz, the process of dielectric relaxation begins, leading to an increase in the dielectric loss tangent. The dielectric characteristics of these ceramic samples under conditions of blocking through conduction are determined

scholarly journals Sensitivity analysis for the appraisal of hydrofractures in horizontal wells with borehole resistivity measurements

Geophysics ◽  
2013 ◽  
Vol 78 (4) ◽  
pp. D209-D222 ◽  
Author(s):  
David Pardo ◽  
Carlos Torres-Verdín
Keyword(s):  
High Frequency ◽  
Horizontal Well ◽  
Low Frequency ◽  
Horizontal Wells ◽  
Hydraulic Fractures ◽  
Electrically Conductive ◽  
Resistivity Measurements ◽  
Electromagnetic Measurements ◽  
Open Hole ◽  
Thin Disks

We numerically evaluate the possibility of using borehole electromagnetic measurements to diagnose and quantify hydraulic fractures that have been artificially generated in a horizontal well. Hydrofractures are modeled as thin disks perpendicular to the well and filled with either sand-based or electrically conductive proppant. The study focuses on the effect of thickness and length (radius) of hydrofractures to assess their effects on specific configurations of borehole-resistivity instruments. Numerical results indicate that several measurements (e.g., those obtained with low- and high-frequency solenoids) could be used to assess the thickness of a fracture. However, only low-frequency measurements performed with electrodes and large-spacing between transmitter and receivers (18 m) exhibit the necessary sensitivity to reliably and accurately estimate the length of long hydrofractures (up to 150 m) in open-hole wells. In the case of steel-cased wells, the casing acts as a long electrode, whereby conventional low-frequency short-spaced, through-casing measurements are suitable for the accurate diagnosis of long hydrofractures (up to 150 m in length).

Classical and quantum ergodicity

2017 ◽  
Author(s):  
Christopher D. Sogge
Keyword(s):  
Dynamical Systems ◽  
Invariant Measure ◽  
Ergodic Theory ◽  
High Frequency ◽  
Limit Theorems ◽  
Initial Development ◽  
Quantum Ergodicity ◽  
Physical Problems ◽  
Pure Mathematics ◽  
Important Branch

This chapter proves results involving the quantum ergodicity of certain high-frequency eigenfunctions. Ergodic theory originally arose in the work of physicists studying statistical mechanics at the end of the nineteenth century. The word ergodic has as its roots two Greek words: ergon, meaning work or energy, and hodos, meaning path or way. Even though ergodic theory's initial development was motivated by physical problems, it has become an important branch of pure mathematics that studies dynamical systems possessing an invariant measure. Thus, this chapter first presents some of the basic limit theorems that are key to the classical theory. It then turns to quantum ergodicity.

Printed Flexible LC Filter Using Additive Micro-Dispensing With Silver Conductive Paste and ECA for Component Attachment

2021 ◽  
Author(s):  
Pradeep Lall ◽  
Jinesh Narangaparambil ◽  
Kyle Schulze ◽  
Scott Miller
Keyword(s):  
High Frequency ◽  
Printed Electronics ◽  
Process Performance ◽  
Electrically Conductive ◽  
Additive Fabrication ◽  
Bode Plot ◽  
Mechanical And Electrical Properties ◽  
Electrically Conductive Adhesive ◽  
Sintering Conditions ◽  
Lc Filter

Abstract Filters are used in a variety of signal processing applications in commercial and defense electronics. The use of additively printed electronics in high-frequency applications requires an understanding of the process-performance interactions versus frequency of operation. Assembly of filters for integration into existing circuits requires additively printed metallization traces in addition to component attachment methods. Comparison of frequency response of the additively-printed filtering circuits vs conventional filters subtractively-fabricated on rigid substrates is needed to determine the performance parity of additive fabrication methods. In this paper, a micro-dispensing device is used to print conductive traces and electrically conductive adhesive (ECA) pads for the attachment of components. The effect of different print parameters on the width and height of the trace has been studied. Mechanical and electrical properties also play an important role in the study of different sintering conditions. Optimized parameters from the printing process and sintering analysis are used to print and compare commercially available LC filter circuitry using the Bode plot.

Cryogenic atomic force microscopy

1991 ◽  
Vol 49 ◽  
pp. 54-55
Author(s):  
K. A. Fisher ◽  
M. G. L. Gustafsson ◽  
M. B. Shattuck ◽  
J. Clarke
Keyword(s):  
Room Temperature ◽  
Rapid Freezing ◽  
Cryogenic Temperatures ◽  
Soft Or ◽  
Electrically Conductive ◽  
Force Microscopy ◽  
Flexible Molecules ◽  
Advantages And Disadvantages ◽  
Atomic Force ◽  
Chemical Perturbation

The atomic force microscope (AFM) is capable of imaging electrically conductive and non-conductive surfaces at atomic resolution. When used to image biological samples, however, lateral resolution is often limited to nanometer levels, due primarily to AFM tip/sample interactions. Several approaches to immobilize and stabilize soft or flexible molecules for AFM have been examined, notably, tethering coating, and freezing. Although each approach has its advantages and disadvantages, rapid freezing techniques have the special advantage of avoiding chemical perturbation, and minimizing physical disruption of the sample. Scanning with an AFM at cryogenic temperatures has the potential to image frozen biomolecules at high resolution. We have constructed a force microscope capable of operating immersed in liquid n-pentane and have tested its performance at room temperature with carbon and metal-coated samples, and at 143° K with uncoated ferritin and purple membrane (PM).

The Microstructure of Steatite (Protoenstatite)

1985 ◽  
Vol 43 ◽  
pp. 236-237
Author(s):  
W. E. Lee ◽  
A. H. Heuer
Keyword(s):  
High Frequency ◽  
Glass Ceramics ◽  
Magnesium Silicate ◽  
Beam Current ◽  
Glassy Matrix ◽  
Angle Of Incidence ◽  
X Ray ◽  
Mechanical And Electrical Properties ◽  
Argon Ions ◽  
High Temperature Polymorph

IntroductionTraditional steatite ceramics, made by firing (vitrifying) hydrous magnesium silicate, have long been used as insulators for high frequency applications due to their excellent mechanical and electrical properties. Early x-ray and optical analysis of steatites showed that they were composed largely of protoenstatite (MgSiO3) in a glassy matrix. Recent studies of enstatite-containing glass ceramics have revived interest in the polymorphism of enstatite. Three polymorphs exist, two with orthorhombic and one with monoclinic symmetry (ortho, proto and clino enstatite, respectively). Steatite ceramics are of particular interest a they contain the normally unstable high-temperature polymorph, protoenstatite.Experimental3mm diameter discs cut from steatite rods (∼10” long and 0.5” dia.) were ground, polished, dimpled, and ion-thinned to electron transparency using 6KV Argon ions at a beam current of 1 x 10-3 A and a 12° angle of incidence. The discs were coated with carbon prior to TEM examination to minimize charging effects.

Simulations of high-resolution images of amorphous silicon films

1986 ◽  
Vol 44 ◽  
pp. 544-545
Author(s):  
G. Y. Fan ◽  
J. M. Cowley
Keyword(s):  
Electron Microscope ◽  
High Frequency ◽  
Fourier Transformation ◽  
Amorphous Materials ◽  
Low Frequency ◽  
Chromatic Aberration ◽  
Structure Information ◽  
Frequency Components ◽  
High Resolution Images ◽  
Spatial Frequency Spectrum

It is well known that the structure information on the specimen is not always faithfully transferred through the electron microscope. Firstly, the spatial frequency spectrum is modulated by the transfer function (TF) at the focal plane. Secondly, the spectrum suffers high frequency cut-off by the aperture (or effectively damping terms such as chromatic aberration). While these do not have essential effect on imaging crystal periodicity as long as the low order Bragg spots are inside the aperture, although the contrast may be reversed, they may change the appearance of images of amorphous materials completely. Because the spectrum of amorphous materials is continuous, modulation of it emphasizes some components while weakening others. Especially the cut-off of high frequency components, which contribute to amorphous image just as strongly as low frequency components can have a fundamental effect. This can be illustrated through computer simulation. Imaging of a whitenoise object with an electron microscope without TF limitation gives Fig. 1a, which is obtained by Fourier transformation of a constant amplitude combined with random phases generated by computer.

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