Search results for "electronics"

A reanalysis of spinal motion during vibration

1987

Calibrated film of the motion of the lumbar spine during vibration was reanalysed, making use of a number of computer based techniques to improve accuracy and reduce measurement noise. The results demonstrated resonant behaviour at about 4 Hz and indicated that at vibration levels of the order of 1 m/s2 there exists bending of the order of 1° (peak to peak) between adjacent vertebrae in the lumbar spine. The bending is complex and involves phase differences along the spine and possibly a rocking motion of the pelvis.

In Vitro Study on Bone Heating during Drilling of the Implant Site: Material, Design and Wear of the Surgical Drill

2020

Objective: An in vitro study was made to compare mean thermal variation according to the material, design and wear of the surgical drills used during dental implant site preparation. Material and methods: Three study groups (stainless steel drills with straight blades

Metal-nanoparticle-G4-DNA conjugates and their DC conductivity measurements

2013

Due to superior self-assembly properties, DNA is a very promising candidate for the basis of future bottom-up solutions for molecular electronics and therefore the conductivity of DNA is a very crucial question. In this work DC conductivity measurements on conjugates consisting of G-quadruplex DNA and metal nanoparticles were carried out. The fabrication and results obtained from the electrical measurements of three types of conjugates (20nm G4-AgNP chains, 20nm G4-AuNP flowers and 60nm G4-AuNPs) are reported. Additionally, 20nm AuNP chains coated with G4 were fabricated but not measured electrically. Results reported here indicate that in ambient conditions G4-DNA exhibits insulating behav…

Engeneering 3D Nanoscale Order in Molecular thin films for organic photovoltaics

2010

Optoelectronic devices based on caesium lead halide perovskite nanocrystals

2020

Tradicionalmente, la implementación de materiales activos en circuitos fotónicos integrados se ha basado en la utilización de semiconductores III-V y vidrios y materiales ferroeléctricos dopados con iones de tierras raras. Sin embargo, en la actualidad existe una alternativa basada en (nano) materiales sintetizados por técnicas de química coloidal. La posibilidad de procesar nanomateriales en solución permite fabricar semiconductores con propiedades ópticas (emisión, absorción, dispersión de luz) que pueden diseñarse durante la síntesis. Además, su naturaleza coloidal permite integrarlas en cualquier arquitectura óptica mediante sencillas técnicas de impresión en tinta. En este contexto, lo…

3D Order for Improved Organic Solar Cells Effiency

2010

Noise effect in a FitzHugh-Nagumo circuit driven by a bichromatic signal

2013

We analyze the response of a nonlinear circuit exactly ruled by the FitzHugh-Nagumo equations. This circuit is submitted to a bichromatic signal including a high frequency and a low frequency. In absence of noise, we show that for an appropriate amplitude of the high frequency driving, the response of the circuit estimated at the low frequency can be optimized via the phenomenon of vibrational resonance. Next, we show that under certain conditions, noise can contribute to the effect of vibrational resonance. Colored noise is also considered. Our experimental results are confirmed by a numerical analysis.

Noise effect in a sine-Gordon Lattice

2013

International audience; This paper is devoted to the influence of internal noise in a sine-Gordon chain exhibiting the well known nonlinear supratransmission phenomenon. It is shown that spatiotemporal noise can trigger breather modes with a given probability in a range of parameters where they do not occur without noise. A frequency analysis is carried out to quantify the degree of coherence of the emitted breather. It is shown that there exists an appropriate amount of noise which ensures the existence of breather modes with the best coherence.

Thermal noise limit for ultra-high vacuum noncontact atomic force microscopy

2013

The noise of the frequency-shift signal Δf in noncontact atomic force microscopy (NC-AFM) consists of cantilever thermal noise, tip–surface-interaction noise and instrumental noise from the detection and signal processing systems. We investigate how the displacement-noise spectral density dz at the input of the frequency demodulator propagates to the frequency-shift-noise spectral density dΔf at the demodulator output in dependence of cantilever properties and settings of the signal processing electronics in the limit of a negligible tip–surface interaction and a measurement under ultrahigh-vacuum conditions. For a quantification of the noise figures, we calibrate the cantilever displacemen…

Modification of a commercial atomic force microscopy for low-noise, high-resolution frequency-modulation imaging in liquid environment.

2011

A key issue for high-resolution frequency-modulation atomic force microscopy imaging in liquids is minimizing the frequency noise, which requires a detailed analysis of the corresponding noise contributions. In this paper, we present a detailed description for modifying a commercial atomic force microscope (Bruker MultiMode V with Nanoscope V controller), aiming at atomic-resolution frequency-modulation imaging in ambient and in liquid environment. Care was taken to maintain the AFMs original stability and ease of operation. The new system builds upon an optimized light source, a new photodiode and an entirely new amplifier. Moreover, we introduce a home-built liquid cell and sample holder …