16 research outputs found
Dynamics of Lithium Dendrite Growth and Inhibition: Pulse Charging Experiments and Monte Carlo Calculations
A K-Band High Power and High Isolation Stacked-FET Single Pole Double Throw MMIC Switch Using Resonating Capacitor
A K-band monolithic microwave integrated circuit (MMIC) transmit and receive (T/R) single pole double throw (SPDT) switch with low insertion loss, high isolation and ultra-high output power is demonstrated using 0.15-μm Gallium Arsenide (GaAs) technology. A shunt field effect transistor (FET) configuration is used to provide low insertion loss and high isolation while the stacked-FET is employed to improve power handling capability. The novel GaAs switch exhibits a minimum measured insertion loss of 1.4 dB and less than 2.5 dB from 22 GHz to 26 GHz as well as 44 dB isolation. The measured input 1-dB power compression point (P1,dB) exceeds 4 W
Ka-band doherty power amplifier with 26.9 dBm output power, 42% peak PAE and 32% back-off PAE using GaAs PHEMTS
The authors present the design and development of a two stage Doherty power amplifier (DPA) in the Ka-band. The amplifier is fabricated in a 0.15-μm gallium arsenide (GaAs) pseudomorphic high electron mobility transistor (pHEMT) process. The DPA has a centre frequency of 26.6 GHz, a measured small signal gain of 10.5 dB, output power at 1-dB compression point (P1 dB) of 26.9 dBm, maximum power added efficiency (PAE) of 42%, and PAE of 32% at 6 dB back-off power. To the best of the author's knowledge, this DPA is the first millimetre-wave (mm-wave) power amplifier to achieve a record 32% PAE at 6-dB back-off power from 26.9 dBm at Ka-band
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885. Feasibility of Observing Traffic Patterns (FOOT Patter) in Veterans Health Administration Operating Rooms
Abstract
Background
Surgical site infections (SSIs) complicate nearly 6% of surgeries performed in Veterans Health Administration (VA) hospitals and occur despite adoption of practices known to reduce them. SSIs are associated with prolonged hospitalization and an increased risk of readmission, reoperation and mortality. Operating room (OR) door openings may increase SSI through disruption of desired OR air flow patterns and increased wound microbe counts. Our study objectives were to: 1) develop a methodological approach for collecting data on entry/exit traffic patterns in VA ORs and 2) characterize patterns across different surgery types.
Methods
Trained researchers from 10 VA-Centers for Disease Control and Prevention (CDC) Practice-based Research Network sites observed staff entering and exiting VA ORs. Staff were categorized and identified by role. Exits/entries were recorded on a standardized tracking sheet. Surgery type and observation duration from incision to closure were noted. Mean hourly door openings across procedure and role types were compared via a one-way ANOVA using Stata ver. 15.0.
Results
We observed 56 surgeries on 55 patients (Fig. 1). During 9,801 observation minutes, 766 staff opened doors 3,882 times. Door openings by role differed significantly (p < 0.001) with nurses, perfusionists, anesthesia and vendors having the highest mean door-opening rate. Coronary artery bypass grafts (CABGs) accounted for most door openings and significantly greater surgical duration than other procedures (p=0.012). Time-adjusted OR door opening rate was similar across procedure types at ~22-26 hourly openings (p=0.186).
Figure 1. FOOT Patter results
Conclusion
The hourly rate of door openings varied notably by staff role. Our data show that measurement of OR movements is feasible although gaining access and approval to observe, achieving ideal observer positioning in complex floor plans, and potential misidentification of entering/exiting staff are challenges of direct methods. Scaling this study up may require automated processes. Studies exploring influences of traffic patterns on OR air quality metrics and impact on risk of SSI, identifying rationale and necessity for door openings and effective strategies for reducing unneeded door openings are needed.
Disclosures
All Authors: No reported disclosure
High electronic conductivity as the origin of lithium dendrite formation within solid electrolytes
60-GHz Millimeter-Wave Radio: Principle, Technology, and New Results
The worldwide opening of a massive amount of unlicensed spectra around 60 GHz has triggered great interest in developing affordable 60-GHz radios. This interest has been catalyzed by recent advance of 60-GHz front-end technologies. This paper briefly reports recent work in the 60-GHz radio. Aspects addressed in this paper include global regulatory and standardization, justification of using the 60-GHz bands, 60-GHz consumer electronics applications, radio system concept, 60-GHz propagation and antennas, and key issues in system design. Some new simulation results are also given. Potentials and problems are explained in detail