scholarly journals Estimation of Current Density Using High-Speed-Camera Recordings in a Model Spark Gap during Surge Currents

2019 ◽  
Vol 6 (1) ◽  
pp. 60-64
Author(s):  
T. H. Kopp ◽  
E. Peters ◽  
M. Kurrat
Keyword(s):  
Current Density ◽  
Radiation Intensity ◽  
High Speed ◽  
Experimental Investigations ◽  
High Speed Camera ◽  
Spark Gap ◽  
Plasma State ◽  
Development Processes ◽  
Current Densities ◽  
Short Time

<p>For experimental investigations of short time plasma in spark gaps, as used in surge protective devices, high-speed camera recordings are used frequently. The analysis of these recordings provides further details regarding the plasma state and distribution. These deduced details are used to assist research and development processes. <br />To increase the benefit of high-speed camera recordings an empirical model is presented to improve the picture analysis. In this model the recorded radiation intensity is empirically related to the current density within a spark gap. Therefore a specially adapted model spark gap was developed and tested. In this model spark gap areas with homogenous current densities occur. These current densities are determined in the experimental setup through current measurements with separated electrodes. Additionally, the relative radiation intensity between the electrodes is identified using high-speed camera recordings. An empirical correlation between these two measurement values was found and is discussed. <br />It confirmed that the determined correlation improve the mostly intuitive interpretation of high speed camera recordings in spark gaps.</p>

High-speed SnAG Solder Electroplating Process and Developments on Cost Reduction

2011 ◽  
Vol 2011 (DPC) ◽  
pp. 000717-000753
Author(s):  
Bob Forman
Keyword(s):  
High Speed ◽  
Consumer Electronics ◽  
Wafer Level ◽  
Solder Bumps ◽  
New Process ◽  
Snag Solder ◽  
Single Use ◽  
Current Densities ◽  
Electroplating Process ◽  
Short Time

The use of wafer level packaged ICs with Lead (Pb) free Tin Silver (SnAg) solder bumps is prevalent in consumer electronics. One method of making these bumps is by electroplating. The current process requires the use of a complex and expensive, single use chemistry. These chemistries do provide smooth, void free bumps, but with a very high Cost of Ownership (COO). Up to now these chemistries were expensive to operate, mainly because they are used for a short time and then disposed. This paper will discuss a new process using chemistry that provides improved COO by incorporating higher plating rates with recycling of used chemistry. With this process it is possible to recover nearly 100% of the metals, acids and organic agents previously discharged as waste. The recovered chemistry is then processed and certified to be reused in the originating fab, resulting in virtually zero waste. In addition to closed loop recycling, the process also forms bumps at a higher rate, by plating at higher current densities, with no trade-off in bump performance.

scholarly journals Nanocrystalline Ni-Co Alloy Synthesis by High Speed Electrodeposition

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Jamaliah Idris ◽  
Chukwuekezie Christian ◽  
Eyu Gaius
Keyword(s):  
Current Density ◽  
High Speed ◽  
Cathodic Current Density ◽  
Cathodic Current ◽  
Homogeneous Surface ◽  
Constant Ph ◽  
Current Densities ◽  
Pure Metals ◽  
Aluminum Substrates ◽  
Co Alloys

Electrodeposition of nanocrystals is economically and technologically viable production path for the synthesis of pure metals and alloys both in coatings and bulk form. The study presents nanocrystalline Ni-Co alloy synthesis by high speed electrodeposition. Nanocrystalline Ni-Co alloys coatings were prepared by direct current (DC) and deposited directly on steel and aluminum substrates without any pretreatment, using high speed electrodeposition method. The influence of the electrolysis parameters, such as cathodic current density and temperature at constant pH, on electrodeposition and microstructure of Ni-Co alloys were examined. A homogeneous surface morphology was obtained at all current densities of the plated samples, and it was evident that the current density and temperature affect the coating thickness of Ni-Co alloy coatings.

scholarly journals Research on Whipping and Jetting Combined Swimming Behavior of Solen strictus Gould

2021 ◽  
Vol 9 (10) ◽  
pp. 1086
Author(s):  
Zhaohui Dong ◽  
Shusheng Bi ◽  
Tian Liu
Keyword(s):  
Ecological Restoration ◽  
Swimming Speed ◽  
Food Environment ◽  
High Speed ◽  
Swimming Behavior ◽  
Behavioral Characteristics ◽  
High Speed Camera ◽  
Razor Clams ◽  
Short Time ◽  
Marine Fishing

Solen strictus Gould are mainly cave dwellers, using their axe feet to dig caves. The Solen strictus Gould also exhibit escape-swimming behavior when food, environment, and so on changes. In this paper, Solen strictus Gould were captured on a high-speed camera as they escaped, and it was found that the Solen strictus Gould whipped while the water spout between the axe foot and the mantle sprayed water outwards. The combined propulsion of these two methods allows the Solen strictus Gould to advance rapidly in a short time. It is calculated that the swimming speed of razor clams is positively correlated with their size and that the adult Solen strictus Gould can travel up to 12 times their body length per second. This study enriches the data on the behavioral characteristics of Solen strictus Gould and is of interest regarding Solen strictus Gould in artificial farming, marine fishing, offshore ecological restoration, and underwater bionic robot development.

scholarly journals Experimental Investigations of Motion of Slide of Selected Pistol Types

2016 ◽  
Vol 7 (4) ◽  
pp. 23-32
Author(s):  
Bartosz FIKUS ◽  
Wojciech KOPERSKI ◽  
Paweł PŁATEK ◽  
Zbigniew SURMA ◽  
Radosław TRĘBIŃSKI
Keyword(s):  
High Speed ◽  
Theoretical Models ◽  
Interaction Force ◽  
Experimental Investigations ◽  
Velocity Versus ◽  
High Speed Camera ◽  
Intensive Phase ◽  
Average Value ◽  
Technical Solutions ◽  
Slide Velocity

In the presented paper, kinematic characteristics of movable parts of investigated pistols have been experimentally determined with application of high speed camera and appropriate software TEMA motion. Results of measurements can be useful in validation of various theoretical models and can reveal the influence of some technical solutions on parameters of motion of selected parts. Obtained curves presenting dependence of slide velocity versus time, allowed for rough estimation of average value of interaction force between slide and frame of the investigated construction. The results of study highlights advantage of HK USP pistol design. The achieved results are from reduction of the value of the mentioned interaction force (approximately 50%) due to elongation of the most intensive phase of slide motion damping process.

Facet Topography and Dislocation Structure as a Possible Source for Electrical Heterogeneity in [001] TILT Bicrystals of YBa2Cu3O7-δ

1996 ◽  
Vol 54 ◽  
pp. 338-339
Author(s):  
I-Fei Tsu ◽  
D.L. Kaiser ◽  
S.E. Babcock
Keyword(s):  
Grain Boundary ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Electromagnetic Properties ◽  
Length Scale ◽  
Density Values ◽  
Current Densities ◽  
Applied Fields ◽  
A Current

A current theme in the study of the critical current density behavior of YBa2Cu3O7-δ (YBCO) grain boundaries is that their electromagnetic properties are heterogeneous on various length scales ranging from 10s of microns to ˜ 1 Å. Recently, combined electromagnetic and TEM studies on four flux-grown bicrystals have demonstrated a direct correlation between the length scale of the boundaries’ saw-tooth facet configurations and the apparent length scale of the electrical heterogeneity. In that work, enhanced critical current densities are observed at applied fields where the facet period is commensurate with the spacing of the Abrikosov flux vortices which must be pinned if higher critical current density values are recorded. To understand the microstructural origin of the flux pinning, the grain boundary topography and grain boundary dislocation (GBD) network structure of [001] tilt YBCO bicrystals were studied by TEM and HRTEM.

Electron-beam damage of oxides at high current densities

1989 ◽  
Vol 47 ◽  
pp. 634-635
Author(s):  
M. R. McCartney ◽  
J. K. Weiss ◽  
David J. Smith
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Current Density ◽  
Transition Metal Oxides ◽  
Time Resolved ◽  
Rapid Acquisition ◽  
Resolution Electron ◽  
Current Densities ◽  
Electron Stimulated Desorption ◽  
Channel Analyzer

It is well-known that electron-beam irradiation within the electron microscope can induce a variety of surface reactions. In the particular case of maximally-valent transition-metal oxides (TMO), which are susceptible to electron-stimulated desorption (ESD) of oxygen, it is apparent that the final reduced product depends, amongst other things, upon the ionicity of the original oxide, the energy and current density of the incident electrons, and the residual microscope vacuum. For example, when TMO are irradiated in a high-resolution electron microscope (HREM) at current densities of 5-50 A/cm2, epitaxial layers of the monoxide phase are found. In contrast, when these oxides are exposed to the extreme current density probe of an EM equipped with a field emission gun (FEG), the irradiated area has been reported to develop either holes or regions almost completely depleted of oxygen. ’ In this paper, we describe the responses of three TMO (WO3, V2O5 and TiO2) when irradiated by the focussed probe of a Philips 400ST FEG TEM, also equipped with a Gatan 666 Parallel Electron Energy Loss Spectrometer (P-EELS). The multi-channel analyzer of the spectrometer was modified to take advantage of the extremely rapid acquisition capabilities of the P-EELS to obtain time-resolved spectra of the oxides during the irradiation period. After irradiation, the specimens were immediately removed to a JEM-4000EX HREM for imaging of the damaged regions.

Product Modeling, Evaluation and Validation at the Detailed Design Stage

2011 ◽  
Author(s):  
Cristian Iorga ◽  
Alain Desrochers
Keyword(s):  
Product Development ◽  
Design Process ◽  
Design Stage ◽  
Product Modeling ◽  
Specific Product ◽  
Development Processes ◽  
Product Variation ◽  
Process Methodology ◽  
Capstone Projects ◽  
Short Time

The expansion of the markets corroborated with product customization and short time to launch the product have led to new levels of competition among product development companies. To be successful in the globalization of the markets and to enable the evaluation and validation of products, companies have to develop methodologies focused on lifecycle analysis and reduction of product variation to obtain both quality and robustness of products. Keywords: Modeling, Evaluation, Validation, Design ProcessThis paper proposes a new design process methodology that unifies theoretical results of modeling stage and empirical findings obtained from the validation stage. The evaluations and validations of engineering design are very important and they have a high influence on product performances and their functionality, as well on the customer perceptions.Given that most companies maintain the confidentiality of their product development processes and that the existing literature does not provide more detailed aspects of this field, the proposed methodology will represent a technical and logistical support intended for students or engineers involved in academic as well as industrial projects.A generic methodology will be refined based on a new approach that will take into consideration the specification types (quantitative or qualitative), the design objectives and the product types: new/improved, structural/esthetic. Hence the new generic methodology will be composed of specific product validation algorithms taking into account the above considerations. At the end of this paper, the improvements provided by the proposed methodology into the design process will be shown in the context of the engineering student capstone projects at the Université de Sherbrooke.

scholarly journals Neuro-Inspired Computing with Spin-VCSELs

2021 ◽  
Vol 11 (9) ◽  
pp. 4232
Author(s):  
Krishan Harkhoe ◽  
Guy Verschaffelt ◽  
Guy Van der Sande
Keyword(s):  
Processing Speed ◽  
Delay Time ◽  
High Speed ◽  
State Of The Art ◽  
Polarization Modulation ◽  
Time Interval ◽  
Computing Technique ◽  
High Modulation ◽  
Short Time ◽  
Modulation Speed

Delay-based reservoir computing (RC), a neuromorphic computing technique, has gathered lots of interest, as it promises compact and high-speed RC implementations. To further boost the computing speeds, we introduce and study an RC setup based on spin-VCSELs, thereby exploiting the high polarization modulation speed inherent to these lasers. Based on numerical simulations, we benchmarked this setup against state-of-the-art delay-based RC systems and its parameter space was analyzed for optimal performance. The high modulation speed enabled us to have more virtual nodes in a shorter time interval. However, we found that at these short time scales, the delay time and feedback rate heavily influence the nonlinear dynamics. Therefore, and contrary to other laser-based RC systems, the delay time has to be optimized in order to obtain good RC performances. We achieved state-of-the-art performances on a benchmark timeseries prediction task. This spin-VCSEL-based RC system shows a ten-fold improvement in processing speed, which can further be enhanced in a straightforward way by increasing the birefringence of the VCSEL chip.

scholarly journals Numerical and Experimental Investigations on Vocal Fold Approximation in Healthy and Simulated Unilateral Vocal Fold Paralysis

2021 ◽  
Vol 11 (4) ◽  
pp. 1817
Author(s):  
Zheng Li ◽  
Azure Wilson ◽  
Lea Sayce ◽  
Amit Avhad ◽  
Bernard Rousseau ◽  
...  
Keyword(s):  
Computational Model ◽  
Vocal Fold ◽  
High Speed ◽  
Computational Models ◽  
Ex Vivo ◽  
Vocal Fold Paralysis ◽  
Future Application ◽  
Experimental Investigations ◽  
Type I ◽  
Mri Scans

We have developed a novel surgical/computational model for the investigation of unilat-eral vocal fold paralysis (UVFP) which will be used to inform future in silico approaches to improve surgical outcomes in type I thyroplasty. Healthy phonation (HP) was achieved using cricothyroid suture approximation on both sides of the larynx to generate symmetrical vocal fold closure. Following high-speed videoendoscopy (HSV) capture, sutures on the right side of the larynx were removed, partially releasing tension unilaterally and generating asymmetric vocal fold closure characteristic of UVFP (sUVFP condition). HSV revealed symmetric vibration in HP, while in sUVFP the sutured side demonstrated a higher frequency (10–11%). For the computational model, ex vivo magnetic resonance imaging (MRI) scans were captured at three configurations: non-approximated (NA), HP, and sUVFP. A finite-element method (FEM) model was built, in which cartilage displacements from the MRI images were used to prescribe the adduction, and the vocal fold deformation was simulated before the eigenmode calculation. The results showed that the frequency comparison between the two sides was consistent with observations from HSV. This alignment between the surgical and computational models supports the future application of these methods for the investigation of treatment for UVFP.

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