Design and construction of a high-speed high-performance direct-drive handpiece

1987 ◽  
Vol 134 (6) ◽  
pp. 286 ◽  
Author(s):  
D.E. Hesmondhalgh ◽  
D. Tipping ◽  
M. Amrani
Keyword(s):  
High Speed ◽  
High Performance ◽  
Direct Drive ◽  
Design And Construction

Test Results and Analytical Predictions for Rotor Drop Testing of an AMB Expander/Generator

2006 ◽  
Author(s):  
Lawrence Hawkins ◽  
Alexei Filatov ◽  
Shamim Imani ◽  
Darren Prosser
Keyword(s):  
High Speed ◽  
High Performance ◽  
Time History ◽  
Test Results ◽  
Direct Drive ◽  
Flow Loop ◽  
Low Loss ◽  
Model Predictions ◽  
Full Speed ◽  
Insight Into

A cryogenic gas expander system that incorporates a high performance, high-speed permanent magnet, direct-drive generator and low loss magnetic bearings is described. Flow loop testing to 30,000 rpm was completed at the system manufacturer’s facility in January 2005, and field installation is scheduled for October 2005. As part of the system testing, the rotor was dropped onto the backup bearings multiple times at an intermediate speed and at 30,000 rpm. Orbit and time-history data from a full speed drop and spin down are presented and discussed in detail. A transient, nonlinear rotordynamic analysis simulation model was developed for the machine to provide insight into the dynamic behavior. The model includes the dead band clearance, the flexible backup bearing support and hard stop. Model predictions are discussed relative to the test data.

Test Results and Analytical Predictions for Rotor Drop Testing of an Active Magnetic Bearing Expander/Generator

2006 ◽  
Vol 129 (2) ◽  
pp. 522-529 ◽  
Author(s):  
Lawrence Hawkins ◽  
Alexei Filatov ◽  
Shamim Imani ◽  
Darren Prosser
Keyword(s):  
High Speed ◽  
High Performance ◽  
Time History ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Test Results ◽  
Direct Drive ◽  
Flow Loop ◽  
Low Loss ◽  
Full Speed

A cryogenic gas expander system that incorporates a high-performance, high-speed permanent magnet, direct-drive generator and low loss magnetic bearings is described. Flow loop testing to 30,000rpm was completed at the system manufacturer’s facility in January 2005, and field installation is scheduled for October 2005. As part of the system testing, the rotor was dropped onto the backup bearings multiple times at an intermediate speed and at 30,000rpm. Orbit and time-history data from a full speed drop and spin down are presented and discussed in detail. A transient, nonlinear rotordynamic analysis simulation model was developed for the machine to provide insight into the dynamic behavior. The model includes the dead band clearance, the flexible backup bearing support, and hard stop. Model predictions are discussed relative to the test data.

High-order, sliding-mode-based precise control of direct-drive systems under heavy uncertainties

2007 ◽  
Vol 221 (5) ◽  
pp. 791-805 ◽  
Author(s):  
S Bogosyan ◽  
A Arabyan
Keyword(s):  
High Speed ◽  
High Performance ◽  
Sliding Mode ◽  
High Order ◽  
The Novel ◽  
Direct Drive ◽  
Tracking Accuracy ◽  
Actuator Dynamics ◽  
Precise Position ◽  
Continuous Input

The high-performance control of direct-drive (DD) systems requires the full system dynamic effects to be taken into account owing to the eliminated gear mechanism. The actuator dynamics and structural flexibilities become of increased importance, particularly when high-speed, high-accuracy operation of lightweight structures is aimed for; however, in most related literature, these effects are neglected to avoid increased computational complexity at the expense of compromising the tracking accuracy of the system in the transient and steady state. As a solution to the problem, in this study, high-order, sliding-mode (HOSM) controllers (HOSMCs) are developed, which exploit the robustness properties of sliding-mode controllers (SMCs) while also increasing accuracy by reducing chattering effects. Different from standard HOSMCs, which are derived by artificially increasing the system order, the third-order HOSM (3-HOSM) control laws in this study are derived by including the actuator dynamics and structural flexibilities in the control design process. Two HOSMCs are developed for this purpose: one with a discontinuous input and one with a continuous input aimed at reducing chattering. The performance of the novel HOSMCs is tested by simulations for the precise position and tracking control of a one-degree-of-freedom (1DOF) DD weapon-positioning system as an example of a direct-drive system under heavy uncertainties and external disturbances. The improved accuracy obtained, particularly with the novel continuous-input 3-HOSMC, motivates the implementation of the schemes for demanding control applications under heavy uncertainties.

Vacuum System to Minimize the Specimen Contamination of High-Performance EM

1977 ◽  
Vol 35 ◽  
pp. 68-69
Author(s):  
N. Yoshimura ◽  
K. Shirota ◽  
T. Etoh
Keyword(s):  
Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
High Vacuum ◽  
Vacuum System ◽  
Pump System ◽  
Pumping System ◽  
Diffusion Pump ◽  
Almost All ◽  
Cascade Type

One of the most important requirements for a high-performance EM, especially an analytical EM using a fine beam probe, is to prevent specimen contamination by providing a clean high vacuum in the vicinity of the specimen. However, in almost all commercial EMs, the pressure in the vicinity of the specimen under observation is usually more than ten times higher than the pressure measured at the punping line. The EM column inevitably requires the use of greased Viton O-rings for fine movement, and specimens and films need to be exchanged frequently and several attachments may also be exchanged. For these reasons, a high speed pumping system, as well as a clean vacuum system, is now required. A newly developed electron microscope, the JEM-100CX features clean high vacuum in the vicinity of the specimen, realized by the use of a CASCADE type diffusion pump system which has been essentially improved over its predeces- sorD employed on the JEM-100C.

PHAX-SCAN: Functional integration of a Scanning Electron Microscope and an energy-dispersive x-ray analyser

1989 ◽  
Vol 47 ◽  
pp. 56-57
Author(s):  
Marc H. Peeters ◽  
Max T. Otten
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
Functional Integration ◽  
Energy Dispersive ◽  
X Rays ◽  
X Ray ◽  
High Speed Analysis ◽  
Scanning Electron

Over the past decades, the combination of energy-dispersive analysis of X-rays and scanning electron microscopy has proved to be a powerful tool for fast and reliable elemental characterization of a large variety of specimens. The technique has evolved rapidly from a purely qualitative characterization method to a reliable quantitative way of analysis. In the last 5 years, an increasing need for automation is observed, whereby energy-dispersive analysers control the beam and stage movement of the scanning electron microscope in order to collect digital X-ray images and perform unattended point analysis over multiple locations.The Philips High-speed Analysis of X-rays system (PHAX-Scan) makes use of the high performance dual-processor structure of the EDAX PV9900 analyser and the databus structure of the Philips series 500 scanning electron microscope to provide a highly automated, user-friendly and extremely fast microanalysis system. The software that runs on the hardware described above was specifically designed to provide the ultimate attainable speed on the system.

The bright future of digital imaging in scanning electron microscopy

1993 ◽  
Vol 51 ◽  
pp. 768-769
Author(s):  
M. T. Postek ◽  
A. E. Vladar
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Digital Imaging ◽  
High Speed ◽  
High Performance ◽  
Mass Storage ◽  
Analog To Digital ◽  
Central Processing ◽  
Digital Imaging Technology ◽  
Scanning Electron

One of the major advancements applied to scanning electron microscopy (SEM) during the past 10 years has been the development and application of digital imaging technology. Advancements in technology, notably the availability of less expensive, high-density memory chips and the development of high speed analog-to-digital converters, mass storage and high performance central processing units have fostered this revolution. Today, most modern SEM instruments have digital electronics as a standard feature. These instruments, generally have 8 bit or 256 gray levels with, at least, 512 × 512 pixel density operating at TV rate. In addition, current slow-scan commercial frame-grabber cards, directly applicable to the SEM, can have upwards of 12-14 bit lateral resolution permitting image acquisition at 4096 × 4096 resolution or greater. The two major categories of SEM systems to which digital technology have been applied are:In the analog SEM system the scan generator is normally operated in an analog manner and the image is displayed in an analog or "slow scan" mode.

Performance Analysis of Various Multipliers Using 8T-full Adder with 180nm Technology

2020 ◽  
Vol 13 (6) ◽  
pp. 864-870
Author(s):  
Sai Venkatramana Prasada G.S ◽  
G. Seshikala ◽  
S. Niranjana
Keyword(s):  
Low Power ◽  
Power Dissipation ◽  
High Speed ◽  
High Performance ◽  
Full Adder ◽  
Fundamental Operation ◽  
Wallace Tree ◽  
Power Delay Product ◽  
The Comparative Study ◽  
Wallace Tree Multiplier

Background: This paper presents the comparative study of power dissipation, delay and power delay product (PDP) of different full adders and multiplier designs. Methods: Full adder is the fundamental operation for any processors, DSP architectures and VLSI systems. Here ten different full adder structures were analyzed for their best performance using a Mentor Graphics tool with 180nm technology. Results: From the analysis result high performance full adder is extracted for further higher level designs. 8T full adder exhibits high speed, low power delay and low power delay product and hence it is considered to construct four different multiplier designs, such as Array multiplier, Baugh Wooley multiplier, Braun multiplier and Wallace Tree multiplier. These different structures of multipliers were designed using 8T full adder and simulated using Mentor Graphics tool in a constant W/L aspect ratio. Conclusion: From the analysis, it is concluded that Wallace Tree multiplier is the high speed multiplier but dissipates comparatively high power. Baugh Wooley multiplier dissipates less power but exhibits more time delay and low PDP.

scholarly journals Ultracompact and low-power-consumption silicon thermo-optic switch for high-speed data

Nanophotonics ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 937-945
Author(s):  
Ruihuan Zhang ◽  
Yu He ◽  
Yong Zhang ◽  
Shaohua An ◽  
Qingming Zhu ◽  
...  
Keyword(s):  
Power Consumption ◽  
Low Power ◽  
High Speed ◽  
High Performance ◽  
Pulse Amplitude ◽  
Telecommunication Networks ◽  
Low Power Consumption ◽  
Power Efficient ◽  
High Speed Data ◽  
On Chip

AbstractUltracompact and low-power-consumption optical switches are desired for high-performance telecommunication networks and data centers. Here, we demonstrate an on-chip power-efficient 2 × 2 thermo-optic switch unit by using a suspended photonic crystal nanobeam structure. A submilliwatt switching power of 0.15 mW is obtained with a tuning efficiency of 7.71 nm/mW in a compact footprint of 60 μm × 16 μm. The bandwidth of the switch is properly designed for a four-level pulse amplitude modulation signal with a 124 Gb/s raw data rate. To the best of our knowledge, the proposed switch is the most power-efficient resonator-based thermo-optic switch unit with the highest tuning efficiency and data ever reported.

scholarly journals High-Speed 3D Printing of High-Performance Thermosetting Polymers via Two-Stage Curing

2018 ◽  
Vol 39 (7) ◽  
pp. 1700809 ◽  
Author(s):  
Xiao Kuang ◽  
Zeang Zhao ◽  
Kaijuan Chen ◽  
Daining Fang ◽  
Guozheng Kang ◽  
...  
Keyword(s):  
3D Printing ◽  
High Speed ◽  
High Performance ◽  
Two Stage ◽  
Thermosetting Polymers
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