scholarly journals The Age-Dependence of Microwave Dielectric Parameters of Biological Tissues

10.5772/51400 ◽  
2012 ◽  
Author(s):  
Mimoza Ibrani ◽  
Luan Ahma ◽  
Enver Hamiti
Keyword(s):  
Biological Tissues ◽  
Age Dependence ◽  
Dielectric Parameters ◽  
Microwave Dielectric

Dielectric parameters relevant to microwave dielectric heating

1998 ◽  
Vol 27 (3) ◽  
pp. 213 ◽  
Author(s):  
Camelia Gabriel ◽  
Sami Gabriel ◽  
Edward H. Grant ◽  
Edward H. Grant ◽  
Ben S. J. Halstead ◽  
...  
Keyword(s):  
Dielectric Heating ◽  
Dielectric Parameters ◽  
Microwave Dielectric ◽  
Microwave Dielectric Heating

Relationship between the Different Amount of LMZBS Glass and Dielectric Properties of Li2(Mg0.96Ni0.04)SiO4 Ceramics

2021 ◽  
Vol 1027 ◽  
pp. 10-14
Author(s):  
Rui Peng ◽  
Yuan Xun Li ◽  
Hua Su ◽  
Yong Cheng Lu ◽  
Xue Ying Wang ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Composite Ceramic ◽  
Solid State Reaction Method ◽  
Sintering Behavior ◽  
Network Analyzer ◽  
Composite Ceramics ◽  
Dielectric Parameters ◽  
Densification Temperature ◽  
Microwave Dielectric

The effect of different amount of LMZBS glass on the sintering behavior, microstructure and microwave dielectric properties of the Li2(Mg0.96Ni0.04)SiO4 ceramics was investigated. The synthesis of materials was based on the solid-state reaction method. The micromorphology of the composite ceramics was confirmed using scanning electron microscopy. The microwave dielectric parameters were measured by the network analyzer. The mechanism of heat transfer coming from LMZBS glass lower the densification temperature of matrix ceramic from 1150°C down to 900°C. Excellent microwave dielectric properties were obtained with 1.2 wt% LMZBS glass sintered at 900°C for 4h (εr=5.77 and Q×f=29,558 GHz at 16 GHz, τf=-14.5 ppm/°C). There was a compatibility between the composite ceramic and Ag. Therefore, the aimed ceramic has great potential value of application in the field of low temperature co-fired ceramics of millimeter-wave devices.

scholarly journals Microwave Dielectric Measurements of 4-Nitroacetanilide at Different Temperatures in Carbon Tetrachloride Solution

2018 ◽  
Vol 34 (6) ◽  
pp. 3123-3128
Author(s):  
Chitra Manro ◽  
Ritu Jain
Keyword(s):  
Relaxation Time ◽  
Carbon Tetrachloride ◽  
Relaxation Process ◽  
Activation Parameters ◽  
Flow Process ◽  
Dielectric Parameters ◽  
Microwave Dielectric ◽  
Different Temperatures ◽  
Intramolecular Rotation ◽  
Probable Relaxation Time

The dielectric properties of 4-Nitroacetanilide have been discussed at four different temperatures in the dilute solution of carbon tetrachloride at a fixed frequency of 9.27GHz. The values of dielectric constant (εʹ), dielectric loss (εʺ), permittivity at an optical frequency (ε∞) and permittivity at a static frequency (ε0) are measured at different temperatures and mole fractions. The values of these dielectric parameters are used to calculate the values of relaxation time for overall molecular rotation (τ1), relaxation time for intramolecular rotation (τ2), most probable relaxation time (τ0) and dipole moment (μ) at different temperatures. In the present investigation we have found higher values of τ2 which indicate the existence of more than one relaxation process in the solution. The values of energy activation parameters for dielectric relaxation process (∆Fε, ∆Hε and ∆Sε) and viscous flow process (∆Fη, ∆Hη and ∆Sη) are also determined and compared for 4-Nitroacetanilide with carbon tetrachloride at different temperatures. It is observed that we may treat both the process as a rate process.

ChemInform Abstract: Dielectric Parameters Relevant to Microwave Dielectric Heating

ChemInform ◽  
2010 ◽  
Vol 29 (35) ◽  
pp. no-no ◽  
Author(s):  
C. GABRIEL ◽  
S. GABRIEL ◽  
E. H. GRANT ◽  
B. S. J. HALSTEAD ◽  
D. M. P. MINGOS
Keyword(s):  
Dielectric Heating ◽  
Dielectric Parameters ◽  
Microwave Dielectric ◽  
Microwave Dielectric Heating

Three-Dimensional Visualization of the T-System of Frog Muscle Using High Voltage Electron Microscopy and a Lanthanum Stain

1977 ◽  
Vol 35 ◽  
pp. 570-571 ◽  
Author(s):  
Lee D. Peachey ◽  
Clara Franzini-Armstrong
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Three Dimensional ◽  
Biological Tissues ◽  
High Voltage Electron Microscopy ◽  
Transverse Tubular System ◽  
Peroxidase Reaction ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
T System

The effective study of biological tissues in thick slices of embedded material by high voltage electron microscopy (HVEM) requires highly selective staining of those structures to be visualized so that they are not hidden or obscured by other structures in the image. A tilt pair of micrographs with subsequent stereoscopic viewing can be an important aid in three-dimensional visualization of these images, once an appropriate stain has been found. The peroxidase reaction has been used for this purpose in visualizing the T-system (transverse tubular system) of frog skeletal muscle by HVEM (1). We have found infiltration with lanthanum hydroxide to be particularly useful for three-dimensional visualization of certain aspects of the structure of the T- system in skeletal muscles of the frog. Specifically, lanthanum more completely fills the lumen of the tubules and is denser than the peroxidase reaction product.

On the High Voltage Electron Microscopy (1 MeV) of Biological Thick Sections

1972 ◽  
Vol 30 ◽  
pp. 464-465
Author(s):  
William H. Massover
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Present Report ◽  
Biological Tissues ◽  
Specimen Preparation ◽  
Technical Problems ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
Voltage Electron ◽  
High Voltage Electron

Stereoscopic examination of thick sections of fixed and embedded biological tissues by high voltage electron microscopy has been shown to allow direct visualization of three-dimensional fine structure. The present report will consider the occurrence of some new technical problems in specimen preparation and Image interpretation that are not common during lower voltage studies of thin sections.Thick Sectioning and Tissue Coloration - Epon sections of 0.5 μm or more that are cut with glass knives do not have a uniform thickness as Judged by their interference colors; these colors change with time during their flotation on the knife bath, and again when drying onto the specimen support. Quoted thicknesses thus must be considered only as rough estimates unless measured in specific regions by other methods. Chloroform vapors do not always result in good spreading of thick sections; however, they will spread spontaneously to large degrees after resting on the flotation bath for several minutes. Ribbons of thick sections have been almost impossible to obtain.

Rapid Critical Point Drying of Tissues in a Parr Bomb

1972 ◽  
Vol 30 ◽  
pp. 400-401
Author(s):  
C.A. Baechler ◽  
W. C. Pitchford ◽  
J. M. Riddle ◽  
C.B. Boyd ◽  
H. Kanagawa ◽  
...  
Keyword(s):  
Critical Point ◽  
Critical Pressure ◽  
Soft Tissues ◽  
Biological Tissues ◽  
Critical Temperatures ◽  
Air Drying ◽  
The Past ◽  
Critical Point Drying ◽  
Great Stress ◽  
Infiltration Techniques

Preservation of the topographic ultrastructure of soft biological tissues for examination by scanning electron microscopy has been accomplished in the past by using lengthy epoxy infiltration techniques, or dehydration in ethanol or acetone followed by air drying. Since the former technique requires several days of preparation and the latter technique subjects the tissues to great stress during the phase change encountered during air-drying, an alternate rapid, economical, and reliable method of surface structure preservation was developed. Turnbill and Philpott had used a fluorocarbon for the critical point drying of soft tissues and indicated the advantages of working with fluids having both moderately low critical pressures as well as low critical temperatures. Freon-116 (duPont) which has a critical temperature of 19. 7 C and a critical pressure of 432 psi was used in this study.

Applications of Time-OF-Flight Secondary Ion Mass Spectrometry (TOF-SIMS)

1990 ◽  
Vol 48 (2) ◽  
pp. 308-309
Author(s):  
Bruno Schueler ◽  
Robert W. Odom
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Structural Information ◽  
Time Of Flight ◽  
Biological Tissues ◽  
Polymer Surfaces ◽  
Tof Sims ◽  
Secondary Ions ◽  
Ion Mass Spectrometry ◽  
Secondary Ion

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) provides unique capabilities for elemental and molecular compositional analysis of a wide variety of surfaces. This relatively new technique is finding increasing applications in analyses concerned with determining the chemical composition of various polymer surfaces, identifying the composition of organic and inorganic residues on surfaces and the localization of molecular or structurally significant secondary ions signals from biological tissues. TOF-SIMS analyses are typically performed under low primary ion dose (static SIMS) conditions and hence the secondary ions formed often contain significant structural information.This paper will present an overview of current TOF-SIMS instrumentation with particular emphasis on the stigmatic imaging ion microscope developed in the authors’ laboratory. This discussion will be followed by a presentation of several useful applications of the technique for the characterization of polymer surfaces and biological tissues specimens. Particular attention in these applications will focus on how the analytical problem impacts the performance requirements of the mass spectrometer and vice-versa.

Microwave dielectric characterization of bulk ferroelectrics

1998 ◽  
Vol 08 (PR9) ◽  
pp. Pr9-113-Pr9-116 ◽  
Author(s):  
C. M. Weil ◽  
R. G. Geyer ◽  
L. Sengupta
Keyword(s):  
Dielectric Characterization ◽  
Microwave Dielectric
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