De-embedding technique for S-parameter measurements under high RF power, coupled to thermal imaging

2006 ◽  
Author(s):  
B. Ivira ◽  
F. Ndagijimana ◽  
R.Y. Fillit
Keyword(s):  
Thermal Imaging ◽  
Rf Power ◽  
Embedding Technique ◽  
S Parameter

scholarly journals A power-scalable linearized model for RF power amplifiers starting from S-parameter measurements

2009 ◽  
Author(s):  
Koen Vandermot ◽  
Yves Rolain ◽  
Gerd Vandersteen ◽  
Rik Pintelon ◽  
Francesco Ferranti ◽  
...  
Keyword(s):  
Power Amplifiers ◽  
Rf Power Amplifiers ◽  
Rf Power ◽  
S Parameter ◽  
Linearized Model

A DE-embedding technique for reflection-based S-parameter measurements of HMICs and MMICs

1995 ◽  
Vol 10 (4) ◽  
pp. 218-222 ◽  
Author(s):  
F. M. Ghannouchi ◽  
F. Beauregard ◽  
R. Hajji ◽  
A. Brodeur
Keyword(s):  
Embedding Technique ◽  
S Parameter

scholarly journals Comparing the Safety and Effectiveness of Dedicated Radiofrequency Transseptal Wires to Electrified Metal Guidewires

2021 ◽  
Author(s):  
Jeremiah Wasserlauf ◽  
Bradley Knight
Keyword(s):  
Thermal Imaging ◽  
Thermal Damage ◽  
Tissue Temperature ◽  
Transseptal Puncture ◽  
Rf Power ◽  
Output Level ◽  
Energy Delivery ◽  
Tissue Heating ◽  
Consistency Effect ◽  
Secondary Endpoints

Application of electrocautery to a metal guidewire can be used to perform transseptal puncture (TSP). Dedicated radiofrequency guidewires (RF) may represent a better alternative. This study compares safety and effectiveness of electrified guidewires to a dedicated RF wire. TSP was performed on porcine hearts using an electrified 0.014” or 0.032” guidewire under various power settings compared to TSP using a dedicated RF wire with 5W power. The primary endpoint was the number of attempts required to achieve TSP. Secondary endpoints included the rate of TSP failure, TSP consistency, effect of the distance between tip of the guidewire and the tip of the dilator, and effect of RF power output level. Qualitative secondary endpoints included tissue puncture defect appearance, thermal damage to the TSP guidewire or dilator, and tissue temperature using thermal imaging. The RF wire required 1.10 ± 0.47 attempts to cross the septum. The 0.014” electrified guidewire required 2.17 ± 2.36 attempts (2.0x higher than the RF wire; p<0.01), and the 0.032” electrified guidewire required 3.90 ± 2.93 attempts (3.5x higher than the RF wire; p<0.01). Electrified guidewires had a higher rate of TSP failure, larger defects, more tissue charring, higher temperatures, and greater tissue heating. Fewer RF applications were required to achieve TSP using a dedicated RF wire compared to an electrified guidewire. Smaller defects and lower tissue temperatures were also observed using the RF wire. Electrified guidewires required greater energy delivery and were associated with equipment damage and tissue charring.

Visualization of the Platelet-Plasma Interface

1977 ◽  
Vol 35 ◽  
pp. 494-495
Author(s):  
D. C. Brindley ◽  
M. McGill
Keyword(s):  
Platelet Rich Plasma ◽  
Coagulation Factors ◽  
Platelet Membrane ◽  
Rabbit Platelet ◽  
Surface Coat ◽  
Special Relationship ◽  
Routine Method ◽  
Embedding Technique ◽  
Biochemical Analyses ◽  
Adsorptive Properties

Morphological and cytochemical studies of platelets have reported a surface coat, or glycocalyx, external to the plasma membrane (1). Biochemical analyses have likewise confirmed the highly adsorptive properties of platelets as transporters of coagulation factors (2). However, visualization of the platelet membrane by conventional EM procedures does not reflect this special relationship between the platelet and its plasma environment. By the routine method of alcohol-propylene oxide dehydration for Epon embedding, the lipid bilayer nature of the platelet membrane appears similar to other blood cells (Fig. 1). A new rapid embedding technique using dimethoxypropane (DMP) as dehydrating agent (13) has permitted ultrastructural analyses of the surface features of the platelet-plasma interface.Aliquots of human or rabbit platelet-rich plasma (PRP) were added to equal volumes of 6% glutaraldehyde in Millonig's buffer at 37° for 45 minutes, rinsed in buffer and postfixed in 1% osmium in Millonig's buffer for 45 minutes.

Investigation of ultra-thin films of YBa2Cu3O7−δ grown on MgO

1990 ◽  
Vol 48 (4) ◽  
pp. 6-7
Author(s):  
S.K. Streiffer ◽  
C.B. Eom ◽  
J.C. Bravman ◽  
T.H. Geballet
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Deposition Process ◽  
Nucleation And Growth ◽  
Multilayer Structures ◽  
Rf Power ◽  
Oxygen Loss ◽  
Transmission Electron ◽  
Single Target ◽  
Mtorr Argon

The study of very thin (<15 nm) YBa2Cu3O7−δ (YBCO) films is necessary both for investigating the nucleation and growth of films of this material and for achieving a better understanding of multilayer structures incorporating such thin YBCO regions. We have used transmission electron microscopy to examine ultra-thin films grown on MgO substrates by single-target, off-axis magnetron sputtering; details of the deposition process have been reported elsewhere. Briefly, polished MgO substrates were attached to a block placed at 90° to the sputtering target and heated to 650 °C. The sputtering was performed in 10 mtorr oxygen and 40 mtorr argon with an rf power of 125 watts. After deposition, the chamber was vented to 500 torr oxygen and allowed to cool to room temperature. Because of YBCO’s susceptibility to environmental degradation and oxygen loss, the technique of Xi, et al. was followed and a protective overlayer of amorphous YBCO was deposited on the just-grown films.

Flat embeddment of monolayer cells, tissue sections, and other cellular materials attached onto glass substrate

1990 ◽  
Vol 48 (3) ◽  
pp. 766-767
Author(s):  
Jeffrey P. Chang ◽  
Jaang J. Wang
Keyword(s):  
Present Report ◽  
Cellular Materials ◽  
Cover Glass ◽  
Tissue Sections ◽  
Embedding Technique ◽  
Exfoliated Cells ◽  
Black Paper ◽  
Cell Concentrations ◽  
Flat Embedding

Flat embeddment of certain specimens for electron microscopy is necessary for three classes of biological materials: namely monolayer cells, tissue sections of paraffin or plastics, as well as cell concentrations, exfoliated cells, and cell smears. The present report concerns a flat-embedding technique which can be applied to all these three classes of materials and which is a modified and improved version of Chang's original methodology.Preparation of coverglasses and microslides. Chemically cleaned coverglasses, 11 × 22 mm or other sizes, are laid in rows on black paper. Ink-mark one coner for identifying the spray-side of the glass for growing cells. Lightly spray with Teflon monomer (Heddy/Contact Inductries, Paterson, NO 07524, U.S.A.) from a pressurized can. Bake the sprayed glasses at 500°F for 45 min on Cover-Glass Ceramic Racks (A. Thomas Co. Philadelphia), for Teflon to polymerize.Monolayer Cells. After sterilization, the Teflon-treated coverglasses, with cells attached, are treated or fixed in situ in Columbia staining dishes (A. Thomas Co., Philadelphia) for subsequent processing.

Involvement of nucleus in the maturation of dengue-2 virus in C6/36 cells

1990 ◽  
Vol 48 (3) ◽  
pp. 912-913
Author(s):  
Jaang J. Wang ◽  
Cheng C. Chen ◽  
Men F. Shaio ◽  
Chia T. Liu ◽  
Chung S. Lee ◽  
...  
Keyword(s):  
Culture Medium ◽  
Cytopathic Effect ◽  
Fetal Bovine Serum ◽  
Virus Particles ◽  
Electron Microscopies ◽  
Embedding Technique ◽  
Fetal Bovine ◽  
Flat Embedding ◽  
20 Nm ◽  
Labeling Method

The involvement of nucleus in the maturation processes of Dengue-2 virus in a mosquito cell line, C6/36 cells, has been identified by the electron microscopy and immunocytochemistry. The C6/36 cells were obtained from ATCC and maintained in MEM culture medium containing 10% fetal bovine serum at 28°C. The cell suspensions or cells grown on teflon-coated coverslips were infected with Dengue-2 virus (107/ml) for various time periods of 2 hours, 3, 6, 8, and 10 days. The cells were then fixed in buffered 1.5% glutaraldehyde, and washed in acetone before immunolabeled with monoclonal antibody. An indirect immunocytochemical labeling method of avidin-biotin complex (ABC) conjugated with peroxidase or gold particles (20 nm in diameter) and a flat embedding technique were used to localize the virus particles.At early stages of infections (before 3 days), there were no virion particles detected. After 6 days and on of infections, cytopathic effect (CPE) was observed and showed positive immuno-peroxidase reactions under the light and electron microscopies.

Analysis of Sputtered Zinc Oxide Films

1980 ◽  
Vol 38 ◽  
pp. 416-417
Author(s):  
T. A. Emma ◽  
M. P. Singh
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Piezoelectric Materials ◽  
Oxide Films ◽  
Optical Quality ◽  
Zno Films ◽  
Rf Power ◽  
X Ray Diffraction ◽  
Sputtered Films ◽  
Zinc Oxide Films

Optical quality zinc oxide films have been characterized using reflection electron diffraction (RED), replication electron microscopy (REM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Significant microstructural differences were observed between rf sputtered films and planar magnetron rf sputtered films. Piezoelectric materials have been attractive for applications to integrated optics since they provide an active medium for signal processing. Among the desirable physical characteristics of sputtered ZnO films used for this and related applications are a highly preferred crystallographic texture and relatively smooth surfaces. It has been found that these characteristics are very sensitive to the type and condition of the substrate and to the several sputtering parameters: target, rf power, gas composition and substrate temperature.

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