Hybrid electromagnetic launcher with pneumatic assist — Influence of coil-gun “switch on” and “switch off” time upon missile velocity

2016 ◽  
Author(s):  
Jaroslaw Domin
Keyword(s):  
Electromagnetic Launcher ◽  
Off Time

Effekte von L-Dopa auf die Speicherung und den Abruf verbaler Informationen bei Schlaganfallpatienten

2004 ◽  
Vol 15 (4) ◽  
pp. 275-286 ◽  
Author(s):  
D. Golz ◽  
E. Erdfelder
Keyword(s):  
Off Time

Zusammenfassung: In einer Doppel-Blind-Studie wurde geprüft, ob das katecholaminerg stimulierende Medikament L-Dopa die Gedächtnisleistungen von Schlaganfallpatienten steigern kann. 37 Patienten wurden zur On-Time und Off-Time des Medikaments einer neuropsychologischen Untersuchung unterzogen. Mittels Varianzanalysen konnte gezeigt werden, dass L-Dopa die verbalen episodischen Gedächtnisleistungen verbessern kann, und zwar offenbar speziell die Reproduktion und weniger die Rekognition von Informationen. Analysen auf der Grundlage des Speicherungs-Abruf-Modells von Batchelder und Riefer (1980 , 1986 ) demonstrierten darüber hinaus, dass eher die itemspezifische als die semantisch-relationale Verarbeitung von Itemgruppen profitiert. Eine Steigerung der Aufmerksamkeitsleistung im Sinne der “Alertness” konnte nicht ausgemacht werden, ebenso wenig ein bedeutsamer Zusammenhang von Aufmerksamkeits- und Gedächtnisleistungen. Die Ergebnisse können zusammenfassend dahingehend interpretiert werden, dass insbesondere der Abruf itemspezifischer Informationen durch L-Dopa selektiv gefördert werden kann. Die mögliche vermittelnde Rolle des Neurotransmitters Noradrenalin wird diskutiert.

QUANTITATIVE CRITERIA FOR VALIDATION OF ELECTROENCEPHALOGRAM NEUROFEEDBACK TRAINING PROTOCOL: A PILOT STUDY ON NEUROPATHIC PAIN

2019 ◽  
Vol XVI (4) ◽  
pp. 67-79
Author(s):  
Muhammad Abul Hasan ◽  
Matthew Fraser ◽  
Saad Ahmed Qazi
Keyword(s):  
Neuropathic Pain ◽  
Pilot Study ◽  
Learning Ability ◽  
Alpha Band ◽  
Neurofeedback Training ◽  
Off Time ◽  
Training Protocol

Neurofeedback (NF) training has been used for the treatment of neuropathic pain. This paper presents the results of assessment of the learning ability of five patients having neuropathic pain. The following two types of baselines were adopted: Baseline 1 refers to power on Day 1 in PreNF state; and Baseline 2 refers to power recorded on each training day in PreNF state. The result of the study demonstrated that not only the baseline its selection is also important to demonstrate the validity of training protocol. It was also found that Baseline 2 can be used to define cut-off time for training (when training should be stopped). All five patients can be classified as learner and alpha band was found to be most relevant for NF training.

Electromagnetic-launch-based method for cost-efficient space debris removal

2020 ◽  
Vol 29 (1) ◽  
pp. 94-106
Author(s):  
Chongyuan Hou ◽  
Yuan Yang ◽  
Yikang Yang ◽  
Kaizhong Yang ◽  
Xiao Zhang ◽  
...  
Keyword(s):  
Space Debris ◽  
Orbit Space ◽  
Low Earth Orbit ◽  
Research Progress ◽  
Area Of Interest ◽  
Electromagnetic Launch ◽  
Debris Removal ◽  
Significant Research ◽  
Electromagnetic Launcher ◽  
Cost Efficient

AbstractThe increase in space debris orbiting Earth is a critical problem for future space missions. Space debris removal has thus become an area of interest, and significant research progress is being made in this field. However, the exorbitant cost of space debris removal missions is a major concern for commercial space companies. We therefore propose the debris removal using electromagnetic launcher (DREL) system, a ground-based electromagnetic launch system (railgun), for space debris removal missions. The DREL system has three components: a ground-based electromagnetic launcher (GEML), suborbital vehicle (SOV), and mass of micrometer-scale dust (MSD) particles. The average cost of removing a piece of low-earth orbit space debris using DREL was found to be approximately USD 160,000. The DREL method is thus shown to be economical; the total cost to remove more than 2,000 pieces of debris in a cluster was only approximately USD 400 million, compared to the millions of dollars required to remove just one or two pieces of debris using a conventional space debris removal mission. By using DREL, the cost of entering space is negligible, thereby enabling countries to remove their space debris in an affordable manner.

scholarly journals Active Clamp Boost Converter with Blanking Time Tuning Considered

2021 ◽  
Vol 11 (2) ◽  
pp. 860
Author(s):  
Yeu-Torng Yau ◽  
Kuo-Ing Hwu ◽  
Yu-Kun Tai
Keyword(s):  
Boost Converter ◽  
Zero Current Switching ◽  
Active Clamp ◽  
Overall Efficiency ◽  
Auto Tuning ◽  
Voltage Spike ◽  
Resonant Inductor ◽  
Off Time ◽  
Conduction Mode ◽  
Time Point

An active clamp boost converter with blanking time auto-tuned is presented herein, and this is implemented by an additional auxiliary switch, an additional resonant inductor, and an additional active clamp capacitor as compared with the conventional boost converter. In this structure, both the main and auxiliary switches have zero voltage switching (ZVS) turn-on as well as the output diode has zero current switching (ZCS) turn-off, causing the overall efficiency of the converter to be upgraded. Moreover, as the active clamp circuit is adopted, the voltage spike on the main switch can be suppressed to some extent whereas, because of this structure, although the input inductor is designed in the continuous conduction mode (CCM), the output diode can operate with ZCS turn-off, leading to the resonant inductor operating in the discontinuous conduction mode (DCM), hence there is no reverse recovery current during the turn-off period of the output diode. Furthermore, unlike the existing soft switching circuits, the auto-tuning technique based on a given look-up table is added to adjust the cut-off time point of the auxiliary switch to reduce the current flowing through the output diode, so that the overall efficiency is upgraded further. In this paper, basic operating principles, mathematic deductions, potential designs, and some experimental results are given. To sum up, the novelty of this paper is ZCS turn-off of the output diode, DCM operation of the resonant inductor, and auto-tuning of cut-off time point of the auxiliary switch. In addition, the efficiency of the proposed converter can be up to 96.9%.

Sign in / Sign up

Export Citation Format

Share Document