scholarly journals Wideband MOEMS for the Calibration of Optical Readout Systems

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7343
Author(s):  
Petr Volkov ◽  
Andrey Lukyanov ◽  
Alexander Goryunov ◽  
Daniil Semikov ◽  
Evgeniy Vopilkin ◽  
...  
Keyword(s):  
Oxygen Plasma ◽  
Thermal Evaporation ◽  
Complex Geometry ◽  
Frequency Range ◽  
Fiber Sensors ◽  
Optical Readout ◽  
Electrostatic Control ◽  
Small Parts ◽  
Complete Process

The paper proposes a technology based on UV-LIGA process for microoptoelectromechanical systems (MOEMS) manufacturing. We used the original combination of materials and technological steps, in which any of the materials does not enter chemical reactions with each other, while all of them are weakly sensitive to the effects of oxygen plasma. This made it suitable for long-term etching in the oxygen plasma at low discharge power with the complete preservation of the original geometry, including small parts. The micromembranes were formed by thermal evaporation of Al. This simplified the technique compared to the classic UV-LIGA and guaranteed high quality and uniformity of the resulting structure. To demonstrate the complete process, a test MOEMS with electrostatic control was manufactured. On one chip, a set of micromembranes was created with different stiffness from 10 nm/V to 100 nm/V and various working ranges from 100 to 300 nm. All membranes have a flat frequency response without resonant peaks in the frequency range 0–200 kHz. The proposed technology potentially enables the manufacture of wide low-height membranes of complex geometry to create microoptic fiber sensors.

APPLICATION OF MEASUREMENT METHODS FOR THE FREQUENCY RANGE 2-150 KHZ TO LONG-TERM MEASUREMENTS IN PUBLIC LOW VOLTAGE NETWORKS

2021 ◽  
Author(s):  
V. Khokhlov ◽  
J. Meyer ◽  
D. Ritzmann ◽  
S. Lodetti ◽  
P. S. Wright ◽  
...  
Keyword(s):  
Low Voltage ◽  
Measurement Methods ◽  
Frequency Range

Oscillations and Long-Lasting Correlations in a Model of the Lateral Geniculate Nucleus and Visual Cortex

2000 ◽  
Vol 84 (4) ◽  
pp. 1863-1868 ◽  
Author(s):  
Kyle L. Kirkland ◽  
Adam M. Sillito ◽  
Helen E. Jones ◽  
David C. West ◽  
George L. Gerstein
Keyword(s):  
Experimental Data ◽  
Visual Cortex ◽  
Cell Membrane ◽  
Lateral Geniculate Nucleus ◽  
Feedback Inhibition ◽  
Frequency Range ◽  
Lateral Geniculate ◽  
Low Threshold ◽  
Thalamocortical System

We have previously developed a model of the corticogeniculate system to explore cortically induced synchronization of lateral geniculate nucleus (LGN) neurons. Our model was based on the experiments of Sillito et al. Recently Brody discovered that the LGN events found by Sillito et al. correlate over a much longer period of time than expected from the stimulus-driven responses and proposed a cortically induced slow covariation in LGN cell membrane potentials to account for this phenomenon. We have examined the data from our model, and we found, to our surprise, that the model shows the same long-term correlation. The model's behavior was the result of a previously unsuspected oscillatory effect, not a slow covariation. The oscillations were in the same frequency range as the well-known spindle oscillations of the thalamocortical system. In the model, the strength of feedback inhibition from the cortex and the presence of low-threshold calcium channels in LGN cells were important. We also found that by making the oscillations more pronounced, we could get a better fit to the experimental data.

scholarly journals Practice and perspectives of using ultrasensitive magnetometers in biomedical research.

2021 ◽  
Author(s):  
Yu.V. Maslennikov ◽  
◽  
◽  
Keyword(s):  
Magnetic Field ◽  
Biomedical Research ◽  
Magnetic Measurements ◽  
Signal To Noise Ratio ◽  
Frequency Range ◽  
Optically Pumped ◽  
Technical Solutions ◽  
Further Development ◽  
The Magnetic Field

There are a large number of sensors for measuring the magnetic field of biological objects. They are characterized by the type of the measured physical parameter (magnetic field strength, magnetic flux, etc.), the level of intrinsic sensitivity, and the frequency range of the recorded signals. The long-term practice of studying biomagnetic signals shows that only SQUID-based magnetometers and optically pumped magnetometers have sensitivity levels sufficient for recording biomagnetic signals with the required signal-to-noise ratio. This chapter reflects the main directions of using such magnetometers and methods of magnetic measurements in biomedical research, gives examples of existing technical solutions, and shows possible ways of their further development.

Long-Term Facilitation in a Swimming Sea Anemone

1959 ◽  
Vol 36 (3) ◽  
pp. 526-532
Author(s):  
DONALD M. WILSON
Keyword(s):  
Sea Anemone ◽  
Experimental Techniques ◽  
Frequency Range ◽  
Nerve Net ◽  
Electric Shocks ◽  
Electrical Shocks ◽  
Probable Site ◽  
A Chain ◽  
Long Term Facilitation

1. Repetition-produced modifications in the behaviour of the swimming sea anemone, Stomphia coccinea, are described. Lowered threshold to number of electrical shocks on successive trials indicates a kind of ‘learning‘ called here longterm facilitation. 2. Dissection of the behaviour into its components, both by experimental techniques and observation of atypical cases, shows the swimming reaction not to be simply a chain of reflexes, but to be ‘centrally’; co-ordinated. 3. The conditions for electrical elicitation of swimming are shocks sufficient in intensity to activate the through-conducting nerve net repeated eight times in the frequency range of 1/2 sec. to 4/sec. Fewer than 8 shocks constitute a subthreshold stimulus in fresh animals; more than 8 are rarely required. 4. Repeated subthreshold stimulation by starfish or by 7 electric shocks result in a long-lasting facilitated state in which the same stimulus repeated hours later may produce a full response. The facilitated condition has been observed to last 7 days. Controls kept without stimulation do not show facilitation. 5. The probable site of this long-term facilitation is discussed. It is suggested that this site is at the point of convergence of the two types of stimulation used and between the through-conducting nerve net and the responding muscles.

Highly-defined bioprinting of long-term vascularized scaffolds with Bio-Trap: Complex geometry functionalization and process parameters with computer aided tissue engineering

Materialia ◽  
2020 ◽  
Vol 9 ◽  
pp. 100560 ◽  
Author(s):  
Ruben Foresti ◽  
Stefano Rossi ◽  
Silvana Pinelli ◽  
Rossella Alinovi ◽  
Matteo Barozzi ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Process Parameters ◽  
Complex Geometry ◽  
Computer Aided

Research on the Rotor of a Ducted Fan Propulsion System of MOSUPS Aircraft Taking into Account Self-Balance during Operation

2015 ◽  
Vol 240 ◽  
pp. 191-197
Author(s):  
Dominik Głowacki ◽  
Krzysztof Bogdański ◽  
Miroslaw Rodzewicz
Keyword(s):  
Complex Geometry ◽  
Dynamic Properties ◽  
Propulsion System ◽  
Term Operation ◽  
Ducted Fan ◽  
Modeling Analysis ◽  
Statically Unbalanced Rotor ◽  
Aerial Vehicle ◽  
Joined Wing

The work concerns the research of a propulsion system for an unmanned aerial vehicle MOSUPS in joined wing configuration. Modeling, analysis and experimental research of a statically unbalanced rotor of a ducted fan propulsion system has been conducted.The aim of the analysis was to determine the critical rotational speeds of the rotor due to the probable excitation of oscillations. Due to the complex geometry, Finite Element Method has been used for the calculations. In the study, the critical frequencies (and also rotational speeds) of the rotor as well as precessional instability, flexibly mounted in the bearings have been calculated. Campbell and SAFE diagrams have been presented.Furthermore, the paper presents the idea for a device for automatic dynamic balancing of the mentioned rotor. A mechanism for changing the position of the correction weights has been developed, allowing for a long term operation of rotating parts without the need to stop the unit and correcting the unbalance.The main motivation for work was to fully understand the working conditions of the propulsion system and dynamic properties of the rotor in order to carry out a proper assessment of their impact on the safe operation of the aircraft.

Wearable Conductive Fiber Sensors for Continuous Joint Movement Monitoring

2004 ◽  
Author(s):  
Peter Gibbs ◽  
H. Harry Asada
Keyword(s):  
Continuous Monitoring ◽  
Design Parameters ◽  
Wearable Sensor ◽  
Functional Requirements ◽  
Joint Movement ◽  
Fiber Sensors ◽  
Flexible Skin ◽  
Conductive Fibers ◽  
Important Design

This paper describes a technique that uses conductive fibers as part of a wearable sensor for continuous monitoring of joint movements. Conductive fibers are incorporated into flexible, skin-tight fabrics that are comfortable and acceptable for long-term wear in everyday settings. Continuous monitoring of single or multi-axis joint movement is therefore possible, even when not in the presence of a therapist. A brief overview of the sensor design is presented, including functional requirements and important design parameters. Misalignment errors that may be created every time the subject takes off and puts on the wearable sensor are accounted for by incorporating an array of fiber sensors around the joint and analyzing each sensor’s sensitivity to joint movement during use. This eliminates any need for re-calibration after an initial calibration.

Long-term Hydrophilicity of TiO2 Nanotubes Induced by Oxygen Plasma Treatment

2018 ◽  
Author(s):  
Metka Benčina ◽  
Ita Junkar ◽  
Tomaž Lampe ◽  
Matic Resnik ◽  
Matjaž Valant ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Tio2 Nanotubes ◽  
Oxygen Plasma ◽  
Oxygen Plasma Treatment

Seismic Resistance of Nonlinearly Deformable Large-Span Spatial Structures, Taking into Account Changing Dynamic Stiffness

2021 ◽  
Vol 887 ◽  
pp. 672-679
Author(s):  
S.R. Razzakov
Keyword(s):  
Complex Geometry ◽  
Nonlinear Models ◽  
Dynamic Stiffness ◽  
Dynamic Strength ◽  
Variable Stiffness ◽  
Short Term ◽  
Large Span ◽  
Spatial Systems ◽  
Accumulation Of Damage

Elaboration analytical and computer modeling, changing dynamic parameters of short-term and long-term loaded nonlinearly deformable large-span spatial shell structures are investigated in this research paper. The proposed physical and geometrically nonlinear models of deformation and computational algorithms for solving dynamic problems are applied to assess the stress-strain state of smooth and ribbed spatial systems with variable stiffness caused by the accumulation of damage and the orthotropic structure reinforced by the ribs of the structures of the studied systems. The possibility of using the proposed method of accounting for variable dynamic stiffnesses in calculations for solving problems of dynamic strength and stability of spatial large-span shells of complex geometry is shown.

TRANSPORT PROPERTIES OF THERMALLY EVAPORATED In2Se3 THIN FILMS

2009 ◽  
Vol 16 (05) ◽  
pp. 723-729 ◽  
Author(s):  
D. NITHYAPRAKASH ◽  
B. PUNITHAVENI ◽  
J. CHANDRASEKARAN
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Ac Conductivity ◽  
Thermal Evaporation ◽  
Frequency Range ◽  
X Ray Diffraction ◽  
Cbh Model ◽  
X Ray ◽  
Correlated Barrier Hopping ◽  
Tan Δ

Thin films of In2Se3 were prepared by thermal evaporation. X-ray diffraction indicated that the as-grown films were amorphous in nature and became polycrystalline γ-In2Se3 films after annealing. The ac conductivity and dielectric properties of In2Se3 films have been investigated in the frequency range 100 Hz–100 kHz. The ac conductivity σ ac is found to be proportional to ωn where n < 1. The temperature dependence of both ac conductivity and the parameter n is reasonably well interpreted by the correlated barrier hopping (CBH) model. The values of dielectric constant ε and loss tangent tan δ were found to increase with frequency and temperature. The ac conductivity of the films was found to be hopping mechanism. In I–V characteristic for different field and temperature were studied and it has been found that the conduction process is Poole–Frenkel type.

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