Substantial Reduction of Reset Current in CoO RRAM with Ta Bottom Electrode

2008 ◽  
Vol 1071 ◽  
Author(s):  
Hisashi Shima ◽  
Fumiyoshi Takano ◽  
Yukio Tamai ◽  
Hidenobu Muramatsu ◽  
Hiroyuki Akinaga ◽  
...  
Keyword(s):  
Voltage Pulse ◽  
Pulse Width ◽  
High Speed ◽  
Bottom Electrode ◽  
Substantial Reduction ◽  
Resistance Switching ◽  
Forming Process ◽  
Height Dependence ◽  
Load Resistor ◽  
Resistance Component

AbstractThe resistance switching in Pt/Co-O/Pt and Ta/Co-O/Pt has been investigated. Compared to Pt/Co-O/Pt, the reset current was more efficiently decreased in Ta/Co-O/Pt by using the load resistor in the forming process, indicating that the embedded resistance component with little parasitic capacitance effectively limits the current in the forming process. The reset process with the reset current lower than 0.15 mA was successfully demonstrated in Ta/Co-O/Pt. In addition, the high speed resistance switching by the voltage pulse with the pulse width of 20 ns was carried out, by investigating the pulse voltage height dependence of reset speed in Ta/Co-O/Pt.

Machine Learning Acoustic Emission Based Monitoring of Cold Forging for Smart Manufacturing: A Review

2021 ◽  
Vol 2 (3) ◽  
Keyword(s):  
Machine Learning ◽  
Acoustic Emission ◽  
Product Quality ◽  
High Speed ◽  
High Rate ◽  
Cold Forging ◽  
Smart Manufacturing ◽  
Forming Process ◽  
Cold Forming ◽  
Effective Manner

Cold forging is a high-speed forming technique used to shape metals at near room temperature. and it allows high-rate production of high strength metal-based products in a consistent and cost-effective manner. However, cold forming processes are characterized by complex material deformation dynamics which makes product quality control difficult to achieve. There is no well defined mathematical model that governs the interactions between a cold forming process, material properties, and final product quality. The goal of this work is to provide a review for the state of research in the field of using acoustic emission (AE) technology in monitoring cold forging process. The integration of AE with machine learning (ML) algorithms to monitor the quality is also reviewed and discussed. It is realized that this promising technology didn’t receive the deserving attention for its implementation in cold forging and that more work is needed.

Dynamic vacuum pressure tracking control with high-speed on-off valves

2018 ◽  
Vol 232 (10) ◽  
pp. 1325-1336 ◽  
Author(s):  
Gang Yang ◽  
Kai Chen ◽  
Linglong Du ◽  
Jingmin Du ◽  
Baoren Li
Keyword(s):  
Mass Flow ◽  
Pulse Width ◽  
High Speed ◽  
Pulse Width Modulation ◽  
Sliding Mode ◽  
Tracking System ◽  
Vacuum Pressure ◽  
Chamber Pressure ◽  
Asymmetric Structure ◽  
The Impact

A vacuum pressure tracking system with high-speed on-off valves is a discontinuous system due to the discrete nature of high-speed on-off valves. Chamber pressure changes in the system are determined by the mass flow rates during the processes of charging and discharging. Here, a sliding mode controller with an asymmetric compensator based on average mass flow rate is designed for accurate vacuum pressure tracking. The controller output signal is converted into the duty cycles of the high-speed on-off valves via a pulse width modulation pulsing scheme. Owing to the extreme asymmetry of the processes, an asymmetric structure comprising one high-speed on-off valve in the charging unit and three high-speed on-off valves in the discharging unit is applied to weaken the impact of asymmetry. In addition, an asymmetric compensator is also designed to modify the pulse width modulation pulsing scheme to further eliminate the asymmetry. Experimental results indicate that the proposed controller achieves better performance in pressure tracking with the asymmetric compensator overcoming process asymmetry and enhancing system robustness.

Dieless Water Jet Incremental Micro-Forming

2018 ◽  
Author(s):  
Yi Shi ◽  
Jian Cao ◽  
Kornel F. Ehmann
Keyword(s):  
Process Parameters ◽  
Thin Shell ◽  
High Speed ◽  
Single Point ◽  
Sheet Thickness ◽  
Water Jet ◽  
Micro Forming ◽  
Forming Process ◽  
Thin Foils ◽  
High Pressure Water Jet

Compared to the conventional single-point incremental forming (SPIF) processes, water jet incremental micro-forming (WJIMF) utilizes a high-speed and high-pressure water jet as a tool instead of a rigid round-tipped tool to fabricate thin shell micro objects. Thin foils were incrementally formed with micro-scale water jets on a specially designed testbed. In this paper, the effects on the water jet incremental micro-forming process with respect to several key process parameters, including water jet pressure, relative water jet diameter, sheet thickness, and feed rate, were experimentally studied using stainless steel foils. Experimental results indicate that feature geometry, especially depth, can be controlled by adjusting the processes parameters. The presented results and conclusions provide a foundation for future modeling work and the selection of process parameters to achieve high quality thin shell micro products.

scholarly journals Numerical Response Surfaces of Volume of Ablation and Retropulsion Amplitude by Settings of Ho:YAG Laser Lithotripter

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Jian J. Zhang ◽  
Jonathan Rutherford ◽  
Metasebya Solomon ◽  
Brian Cheng ◽  
Jason R. Xuan ◽  
...  
Keyword(s):  
Pulse Energy ◽  
Pulse Width ◽  
High Speed ◽  
Operation Time ◽  
Laser Lithotripsy ◽  
Pulse Number ◽  
Response Surfaces ◽  
Ho:Yag Laser ◽  
Energy Pulse ◽  
Best Fit

Objectives.Although laser lithotripsy is now the preferred treatment option for urolithiasis due to shorter operation time and a better stone-free rate, the optimal laser settings for URS (ureteroscopic lithotripsy) for less operation time remain unclear. The aim of this study was to look for quantitative responses of calculus ablation and retropulsion by performing operator-independent experiments to determine the best fit versus the pulse energy, pulse width, and the number of pulses.Methods.A lab-built Ho:YAG laser was used as the laser pulse source, with a pulse energy from 0.2 J up to 3.0 J and a pulse width of 150 μs up to 1000 μs. The retropulsion was monitored using a high-speed camera, and the laser-induced craters were evaluated with a 3-D digital microscope. The best fit to the experimental data is done by a design of experiment software.Results.The numerical formulas for the response surfaces of ablation speed and retropulsion amplitude are generated.Conclusions.The longer the pulse, the less the ablation or retropulsion, while the longer pulse makes the ablation decrease faster than the retropulsion. The best quadratic fit of the response surface for the volume of ablation varied nonlinearly with pulse duration and pulse number.

Struttura competitiva dopo la crisi Alitalia: il caso dela tratta Milano-Roma

2009 ◽  
pp. 167-178
Author(s):  
Giovanna Campopiano ◽  
Josip Kotlar ◽  
Andrea Salanti
Keyword(s):  
Price Competition ◽  
High Speed ◽  
Substantial Reduction ◽  
Air Travel ◽  
Air Transport ◽  
High Speed Rail ◽  
Passenger Traffic ◽  
Transport Services ◽  
Real Price

Air travel routes and high speed rail connection between Milan and Rome after the Alitalia crisis This paper analyses the first available data about changes in passenger traffic and air/rail fares after the Alitalia crisis and the substantial reduction of the travel time between Milan and Rome, due to the improvement of high speed rail on this connection. As recently happened in similar cases within Europe, the rail has gained a significant share of traffic previously attracted by air transport services. Apart from that, a real price competition is prevented by a number of inefficiencies which are mainly due to the monopolistic position of the new Alitalia on the route Milan Linate-Rome Fiumicino and problems of accessibility affecting our airports, and partly our rail stations too. The role of the various authorities potentially involved is burdened, in the last instance, by infrastructural deficiencies.

scholarly journals Characteristics of solar wind suprathermal halo electrons

2020 ◽  
Vol 642 ◽  
pp. A130
Author(s):  
M. Lazar ◽  
V. Pierrard ◽  
S. Poedts ◽  
H. Fichtner
Keyword(s):  
Solar Wind ◽  
High Speed ◽  
Solar Wind Speed ◽  
Substantial Reduction ◽  
Comprehensive Description ◽  
Temperature Plasma ◽  
Magnetic Focusing ◽  
Fast Wind ◽  
Outer Corona ◽  
Halo Population

A suprathermal halo population of electrons is ubiquitous in space plasmas, as evidence of their departure from thermal equilibrium even in the absence of anisotropies. The origin, properties, and implications of this population, however, are poorly known. We provide a comprehensive description of solar wind halo electrons in the ecliptic, contrasting their evolutions with heliospheric distance in the slow and fast wind streams. At relatively low distances less than 1 AU, the halo parameters show an anticorrelation with the solar wind speed, but this contrast decreases with increasing distance and may switch to a positive correlation beyond 1 AU. A less monotonic evolution is characteristic of the high-speed winds, in which halo electrons and their properties (e.g., number densities, temperature, plasma beta) exhibit a progressive enhancement already distinguishable at about 0.5 AU. At this point, magnetic focusing of electron strahls becomes weaker and may be counterbalanced by the interactions of electrons with wave fluctuations. This evolution of halo electrons between 0.5 AU and 3.0 AU in the fast winds complements previous results well, indicating a substantial reduction of the strahl and suggesting that significant fractions of strahl electrons and energy may be redistributed to the halo population. On the other hand, properties of halo electrons at low distances in the outer corona suggest a subcoronal origin and a direct implication in the overheating of coronal plasma via velocity filtration.

Spatial Redistribution of Oxygen Ions in Oxide Resistance Switching Device after Forming Process

2010 ◽  
Vol 49 (6) ◽  
pp. 060215 ◽  
Author(s):  
Takeshi Yajima ◽  
Kohei Fujiwara ◽  
Aiko Nakao ◽  
Tomohiro Kobayashi ◽  
Toshiyuki Tanaka ◽  
...  
Keyword(s):  
Resistance Switching ◽  
Forming Process ◽  
Switching Device ◽  
Oxygen Ions ◽  
Spatial Redistribution

Dielectric-breakdown-like forming process in the unipolar resistance switching of Ta2O5−x thin films

2012 ◽  
Vol 12 (3) ◽  
pp. 846-848 ◽  
Author(s):  
Moon Jee Yoon ◽  
Shin Buhm Lee ◽  
Hyang Keun Yoo ◽  
Soobin Sinn ◽  
Bo Soo Kang
Keyword(s):  
Thin Films ◽  
Dielectric Breakdown ◽  
Resistance Switching ◽  
Forming Process
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