Phase Noise
Mostrando 1-12 de 117 artigos, teses e dissertações.
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1. Low-Overhead Low-Complexity Carrier Phase Recovery Technique for Coherent Multi-Band OFDM-Based Superchannel Systems Enabled by Optical Frequency Combs
Abstract In this paper, we have designed a low-overhead low-complexity carrier phase tracking scheme for OFDM-based superchannel transmission system enabled by optical frequency combs. In this scheme, taking advantage of the broadband phase coherence provided by optical frequency combs among the OFDM-bands, the carrier phase retrieved from pilot-subcarriers
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2021-03
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2. ESTIMATION OF PARAMETERS AND STATES USING A BAYESIAN PARTICLE FILTER FOR THE SULFATE ION ADSORPTION PROCESS IN A FIXED BED COLUMN
Abstract Ensuring that industrial effluents meet quality standards to be released into water bodies is still one of the major environmental concerns. Liquid phase adsoption in fixed bed collumns is one of the most known treatments. Measurements are needed to monitor the process. However, as they are often corrupted by noise from the measuring equipment, perf
Braz. J. Chem. Eng.. Publicado em: 09/12/2019
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3. Comportamiento magnético del acero AISI 304 en ensayos de tracción uniaxial
ABSTRACT During the magnetization process of a ferromagnetic material, the magnetic domain walls are forced to move due to the magnetic field influence. The domain walls must overcome the stress produced by the pinning sites (grain boundary, dislocations, inclusions, etc.), producing discrete jumps in the magnetization. These jumps can be detected with a sen
Matéria (Rio J.). Publicado em: 19/07/2018
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4. Mixed-Hemimicelle Solid Phase Extraction Followed by Dispersive Liquid-Liquid Microextraction of Amphetamines from Biological Samples
In this work, the synthesized Fe3O4 nanoparticles was coated by sodium dodecyl sulfate and then it was used as a sorbent in mixed-hemimicelle solid phase extraction of some amphetamines, as psychoactive drugs, from biological samples. This extraction method was combined with dispersive liquid-liquid microextraction to enhance enrichment factors of targeted a
J. Braz. Chem. Soc.. Publicado em: 2016-11
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5. Use of Magnetic Barkhausen Noise (MBN) to Follow Up the Formation of Sigma Phase in Saf2205 (UNS S31803) Duplex Stainless Steel
Abstract Duplex stainless steels have a structure normally composed of austenite and ferrite in approximately equal proportions. In order to attain control of its fabrication processes and performance, it is important to understand its microstructural evolution, due to the formation of intermetallic phases such as sigma (σ) and chi (χ), which may cause a s
Mat. Res.. Publicado em: 01/08/2016
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6. Phase Noise Effects on Wideband Mobile Radio Channel Sounding
Abstract In this work three wideband mobile radio channel sounding methods are simulated and compared using computational tools. The considered sounders include the traditional STDCC and two other proposed sounding methods that are based on OFDM digital transmission and detection procedures and on matched filtering. The impact of the phase noise introduced b
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2015-12
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7. Quantitative Analysis of Endocrine Disruptors by Comprehensive Two-Dimensional Gas Chromatography
Comprehensive two-dimensional gas chromatography has been successfully applied to the analysis of various organic contaminants; however, few studies report its use in the analysis of endocrine disrupting compounds. These compounds are suspected to cause dysfunction of the endocrine system in humans and animals. This work describes the development of a method
J. Braz. Chem. Soc.. Publicado em: 2015-03
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8. Espectroscopia ultrarrápida do polímero semicondutor luminescente MEH-PPV com excitação no ultravioleta / Ultrafast spectroscopy of the luminescent semiconducting polymer MEH-PPV with ultraviolet excitation
The optoelectronics industry is currently undergoing a transition period in which inorganic materials are being replaced by organic materials, oligomers and polymers, in the fabrication of some types of devices. However, factors such as low efficiency and low lifetime prevent polymer based devices on entering the market definitely. The solution of these issu
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 17/08/2012
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9. Controle ativo acústico estrutural: projeto, simulação e análise de qualidade sonora / Active structural acoustic control: design, simulation and analysis of sound quality
This master thesis deals with the study of active noise and sound quality control systems in automotive applications, and the innovative assessment of their performance based on relevant psychoacoustic metrics in this area such as Loudness, Roughness and Tonality. A methodology for designing and implementing active control systems based on psychoacoustic met
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/08/2012
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10. O campo eletromagnético quantizado submetido a ruído e acoplado a um oscilador mecânico / The quantized electromagnetic field submitted to noise and coupled to a mechanical oscillator
In this project we will investigate the influence of noise in the process of interaction of radiation (quantized field) with the matter (mesoscopic mechanical system). We will consider the mode field confined in a cavity of high quality factor with a fixed mirror and one moving mirror, this treated as a mechanical oscillator susceptible to radiation pressure
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 14/05/2012
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11. Avaliação dos efeitos de exercícios vocais em vozes normais com análise perceptivo-auditiva, acústica e de imagens laríngeas obtidas por videolaringoscopia de alta velocidade / Immediate effects of vocal exercise in normal voices using perceptual, acoustic analysis and of the high-speed videolaryngoscopy images
The aim is to detect the immediate effect of vocal exercises in normal voices. Thirty healthy subjects from 19 to 45 year old with no vocal complains participated in the study. The sustained vowels /a/ and /E/ were recorded in two moments: the first, we recorded the habitual voice, before any exercises; and the second, after from 1 to 5 minutes of continuous
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 20/01/2012
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12. New numerical method for the photoelastic technique
The objective of this research is to find new equations for a novel phase-shifting method in digital photoelasticity. Some innovations are proposed. In terms of phase-shifting, only the analyzer is rotated, and the other equations are deduced by applying a new numerical technique instead of the usual algebraic techniques. This approach can be used to calcula
J. Braz. Soc. Mech. Sci. & Eng.. Publicado em: 2012-12