scholarly journals Towards Electron-Beam-Driven Soft / Polymer Fiber Microrobotics for Vacuum Conditions

2022 ◽  
Author(s):  
O.V. Gradov
Keyword(s):  
Electron Beam ◽  
Wavelet Transforms ◽  
Polymer Fibers ◽  
Polymer Fiber ◽  
Time Resolved ◽  
Fiber Break ◽  
Functional Flexibility ◽  
Different Types ◽  
Fourier Spectra ◽  
Soft Polymer

Abstract. The possibility of creating vacuum robotics based on the polymer structures irradiated by an electron beam, in particular, polymer fibers, which provide high functional flexibility and a variety of states, is discussed. The possibility of using polymer fibers as different types of MEMS-like electromechanical elements is demonstrated - from elastic cantilevers to springs that change their state under the electron beam. Experimentally proved the presence of different functional types of fibers, correlating with their thickness, as well as the phenomenon of the fiber break. A number of exotic forms of dynamics have been demonstrated and a method for their detection has been developed using 2D Fourier spectra, integral spatial characteristics, time resolved correlograms and wavelet transforms (visualized as the scaleograms / scalograms). Access barcodes for the full video records of the corresponding experiments are provided.

Charge Propagation along the Polymer Fiber of Polyhydroxybutyrate: Is it Possible to Apply the Cable Model?

2020 ◽  
Vol 869 ◽  
pp. 246-258
Author(s):  
Oleg V. Gradov ◽  
Margaret A. Gradova ◽  
Anatoly A. Olkhov ◽  
Alexey L. Iordanskiy
Keyword(s):  
Electron Beam ◽  
Nerve Fibers ◽  
Polymer Materials ◽  
Polymer Fibers ◽  
Electric Response ◽  
Polymer Fiber ◽  
Cable Model ◽  
Electrospinning Technique ◽  
Charge Propagation ◽  
Dielectric Polymer

This article considers experimental data on the surface charge propagation along the dielectric polymer fibers. Nonwoven polymer materials based on polyhydroxybutyrate obtained by electrospinning technique were used as an example of dielectric fibers in our experiments. Polymer fiber charging was investigated under the electron beam in a vacuum chamber of the scanning electron microscope. The fiber electric response registration was performed in a TV mode and in dynamic conditions using oscilloscopic sectioning visualization. Digitized images were processed using specialized software by Sobel-Feldman operator (Sobel filter), visualizing isopotential lines of the electron beam-induced emission. The results obtained were analyzed in the framework of the Roll’s cable model, which has been extrapolated from the electrical signal transduction along the nerve fibers to the charge propagation along the dielectric polymer fibers.

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.

XANES Registration by Electron Beam Position Scanning for Time-Resolved Experiment

1997 ◽  
Vol 7 (C2) ◽  
pp. C2-549-C2-552 ◽  
Author(s):  
S. G. Nikitenko ◽  
B. P. Tolochko ◽  
A. N. Aleshaev ◽  
G. N. Kulipanov ◽  
S. I. Mishnev
Keyword(s):  
Electron Beam ◽  
Time Resolved ◽  
Beam Position

scholarly journals Design and construction of a prototype for the analysis of vibrations in an induction motor for the detection of faults

2020 ◽  
pp. 27-33
Author(s):  
Javier Garrido ◽  
Beatris Escobedo-Trujillo ◽  
Guillermo Miguel Martínez-Rodríguez ◽  
Oscar Fernando Silva-Aguilar
Keyword(s):  
Fourier Transform ◽  
Induction Motor ◽  
Wavelet Transforms ◽  
Data Acquisition System ◽  
Time Frequency ◽  
Different Types ◽  
Control Devices ◽  
The Fourier Transform ◽  
And Control ◽  
Types Of Faults

The contribution of this work is to present the design of a prototype integrated by an induction motor, a data acquisition system, accelerometers and control devices for stop and start, to generate and identify different types of faults by means of vibration analysis. in the domain: time, frequency or frequency-time, through the use of the Fourier Transform, Fast Fourier Transform or Wavelet Transforms (wavelet transform). In this prototype, failures can be generated in the induction motor such as: unbalance, different types of misalignment, mechanical looseness, and electrical failures such as broken bars or short-circuited rings, an example of a misalignment failure is presented to show the process of analysis and detection.

scholarly journals Method for Introducing Zeolites and MCM-41 into Polypropylene Melt-Blown Nonwovens

2019 ◽  
Vol 19 (4) ◽  
pp. 312-323
Author(s):  
Agnieszka Brochocka ◽  
Aleksandra Zagawa ◽  
Rafał Panek ◽  
Jarosław Madej ◽  
Wojciech Franus
Keyword(s):  
Functional Materials ◽  
Polymer Fibers ◽  
Protective Equipment ◽  
Silica Material ◽  
Paraffin Oil ◽  
Different Types ◽  
Oil Mist ◽  
European Standards ◽  
Polypropylene Melt ◽  
Mcm 41

Abstract In this work, a method for introducing zeolites and mesoporous siliceous materials into the melt-blown process for the production of polypropylene nonwovens was developed and the functional materials obtained were tested. Both types of additives were introduced in the melt-blown technology using a device placed in the duct of the die assembly. Nine types of polypropylene melt-blown nonwovens were made with different types of zeolites (clinoptilolite, Na-X, Na-A, Na-P1, sodalite, Na-P1 with hexadecyl trimethylammonium bromide (HDTMA), ZeoEco 20, and BioZeo R.01) or mesoporous silica material (Mobil Composition of Matter No. 41, abbreviated as MCM-41). The nonwovens were studied in terms of protective and functional parameters: sodium chloride and paraffin oil mist aerosol penetration, airflow resistance, and sorption capacity for toluene, ammonia, acetone, and cyclohexane, in accordance with the requirements of the European standards concerning respiratory protective equipment. The tests showed that zeolites and MCM-41 can be successfully incorporated within the structure of elementary polymer fibers using an environmentally friendly “dry” melt-blown technology with nonwovens modified so as to impart multiple functionalities in one integrated technological process. The developed method of introducing the studied materials to polypropylene melt-blown nonwovens led to the production of new multipurpose materials with good protective and functional properties. The best polypropylene nonwovens were produced with the addition of 250 g/m2 of MCM-41 or Na-P1 zeolite modified with HDTMA.

scholarly journals Time Resolved Emission of Sidestream Smoke Particles

1992 ◽  
Vol 15 (2) ◽  
pp. 53-57
Author(s):  
R Dittmann ◽  
HJ Feld ◽  
BH Müller ◽  
W Schneider
Keyword(s):  
Time Scales ◽  
Time Resolved ◽  
Smoke Particles ◽  
Sidestream Smoke ◽  
Different Types ◽  
Short Time ◽  
Aerosol Properties

AbstractBy means of the dispersion quotient method, the aerosol properties of freshly produced sidestream smoke were measured during the puff and subsequent interpuff period. These measurements were made on short time scales and at high aerosol concentrations. Examples are presented, which show the influence of different combustion conditions during the puff (resulting from different degrees of ventilation and different types of tobacco) on the emission of sidestream particles during the interpuff period. The ratio of the volume concentrations of the particles before and during a puff is reduced by ventilation and is nearly unchanged by the variation of the tobacco type.

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