Medical texts continue to perpetuate the belief that epinephrine should not be injected in fingers. Little attention has been paid to analyze the evidence that created this belief to see whether it ...is valid. The significance is that elective epinephrine finger injection has been shown to remove the need for a tourniquet, and therefore delete sedation and general anesthesia for much of hand surgery.
All of the evidence for the antiadrenaline dogma comes from 21 mostly pre-1950 case reports of finger ischemia associated with procaine and cocaine injection with epinephrine. The authors performed an in-depth analysis of those 21 cases to determine their validity as evidence. They also examined in detail all of the other evidence in the literature surrounding issues of safety with procaine, lidocaine, and epinephrine injection in the finger.
The adrenaline digital infarction cases that created the dogma are invalid evidence because they were also injected with either procaine or cocaine, which were both known to cause digital infarction on their own at that time, and none of the 21 adrenaline infarction cases had an attempt at phentolamine rescue.
The evidence that created the dogma that adrenaline should not be injected into the fingers is clearly not valid. However, there is considerable valid evidence in the literature that supports the tenet that properly used adrenaline in the fingers is safe, and that it removes the need for a tourniquet and therefore removes the need for sedation and general anesthesia for many hand operations.
Noise due to scattered light has been a frequent disturbance in the advanced LIGO gravitational wave detectors, hindering the detection of gravitational waves. The non stationary scatter noise caused ...by low frequency motion can be recognized as arches in the time-frequency plane of the gravitational wave channel. In this paper, we characterize the scattering noise for LIGO and Virgo's third observing run O3 from April, 2019 to March, 2020. We find at least two different populations of scattering noise and we investigate the multiple origins of one of them as well as its mitigation. We find that relative motion between two specific surfaces is strongly correlated with the presence of scattered light and we implement a technique to reduce this motion. We also present an algorithm using a witness channel to identify the times this noise can be present in the detector.
High power microwave (HPM) sources based on the backward-wave oscillator (BWO) have been investigated for the past two decades primarily because of their potential for very high efficiency (15 to ...40%) operation. Several different effects have been proposed to explain this high efficiency compared to conventional BWOs. One of the major contributors to the high efficiency of the plasma-filled Pasotron HPM BWO source is the presence of optimally phased end reflections. The Pasotron uses a long-pulse (/spl ges/100 /spl mu/s) plasma-cathode electron-gun and plasma filled slow-wave structure to produce microwave pulses in the range of 1 to 10 MW without the use of externally produced magnetic fields. The efficiency of the Pasotron can be enhanced by up to a factor of two when the device is configured as a standing-wave oscillator in which properly phased reflections from the downstream collector end of the finite length SWS constructively interfere with the fundamental backward-wave modes and improve the coupling of the beam to the circuit. Operation in this configuration increases the efficiency up to 30% but causes the frequency to vary in discrete steps and the output power to change strongly with beam parameters and oscillation frequency.
For traveling wave tube (TWT) amplifiers which transmit downlink signals from both geo-synchronous satellites and deep-space spacecraft, the single most important attribute continues to be overall ...dc-to-RF conversion efficiency. Currently, the most popular satellite downlink bands are 3.4 to 4.2 GHz and 10.9 to 12.75 GHz. This paper discusses recent production TWTs at L-3 Communications Electron Technologies, Inc., which are achieving dc-to-rf efficiencies of over 70% at power levels ranging from 65 to 150 W in these high-demand satellite downlink frequency bands. These TWTs continue to provide a large advantage over the use of equivalent solid-state power amplifiers.
For traveling wave tube (TWT) amplifiers which transmit downlink signals from both geo-synchronous satellites and deep-space spacecraft, the single most important attribute continues to be overall ...dc-to-RF conversion efficiency. Currently, the most popular satellite downlink bands are 3.4 to 4.2 GHz and 10.9 to 12.75 GHz. This paper discusses recent production TWTs at L-3 Communications Electron Technologies, Inc., which are achieving dc-to-rf efficiencies of over 70% at power levels ranging from 65 to 150 W in these high-demand satellite downlink frequency bands. These TWTs continue to provide a large advantage over the use of equivalent solid-state power amplifiers.
ION-X is a sub-atmospheric gas storage and delivery system that uses metal-organic-framework (MOF) adsorbents to safely store and deliver ion implant dopant gases. MOFs are a new class of crystalline ...materials with unprecedented surface areas and uniform pore size distributions. The pressure of an ION-X cylinder is below one atmosphere to significantly reduce the hazards associated with a gas release. Compared to zeolite or carbon adsorbent-based legacy products, MOF's high pore density and uniformity provide advantages in storage capacity and gas purity. Arsine and phosphine ION-X was evaluated at Infineon using a Varian VIISion high current implanter and its performance was compared against SDS ® 3. The installation of the new source cylinders was seamless and did not require modifications to the existing tool infrastructure. The ion beam stability and spectral purity generated with ION-X sources was within specifications and indistinguishable from the process of record. On-wafer purity analysis was carried out using Vapor-Phase Decomposition - Inductively Coupled Plasma Mass-Spectrometry (VPD-ICPMS) after test wafers were implanted using ION-X and SDS ® 3 gas sources. The analyses show that all surface trace metals were well below specification limits with no discernable differences between gas sources. Sheet resistance measurements of test wafers were also within the accepted limits with standard deviations similar to the reference. In addition, electrical test data of productive lots show no significant differences in sensitive devices while using ION-X based implants. Based on these evaluations, ION-X hydride dopant gas delivery system performance is reliable, has already been qualified on a pilot tool, and is currently scheduled for roll-out at the Infineon production sites.
Boeing Electron Dynamic Devices, Inc. offers fully qualified, production-ready Ku-band and C-band TWTs for space communications with demonstrated efficiencies exceeding 70%. The C-band 8555HX is a ...30-100 W class TWT that has been qualified in a conduction-cooled package with a mass of 790 grams (no leads). The 8555HX performs at better than 70% efficiency across 300 MHz. The Ku-band model, 88150HX, is a 100-150 W class TWT which is qualified in a radiation-cooled package. The first two 88150HX builds both performed at better than 70% efficiency across a 1 GHz operating band. These efficiency improvements are only intended as a stepping stone on the way to better performance.
F.D.R. in MySpace Feicht, Richard J
The School librarian's workshop,
06/2011, Volume:
31, Issue:
6
Journal Article
Students in a US History class that included 9th, 10th, and 11th graders were assigned to develop a "MySpace" page using PowerPoint presenting themselves as Pres Franklin Roosevelt. They also had to ...research and explain selected New Deal Programs relating to Pres Barack Obama's stimulus plan which were integrated into classroom discussions. Additionally, they had to read an article on Pres Obama's stimulus plan, then express their thoughts and respond to students in the same course but in different periods using the school's "PB Wiki" page in a blog. Here, Feicht details how the students used social networking tools to better understand the issues that the country is facing.
L-3 Communications Electron Technologies, Inc. (L-3 ETI) is producing flight qualified L-band linearized traveling-wave tube amplifiers (LTWTAs) for space communication and navigation systems with ...demonstrated efficiencies to 65%. Thermal test data for a flight set of LTWTAs generating 140 watts of output power at 1540 MHz for a narrow-band (8 MHz) application is presented. Average DC conversion efficiency (η) >; 64%, 2-tone intermodulation distortion (C3IM) below 13 dB (SAT), and phase stability better than 5°, all when tested over a nominal 100 deg C temperature range were achieved. Group delay stability of ~30 pspp over this temperature range is also demonstrated, making these amplifiers ideal for satellite navigation.
PDF
