Wyniki wyszukiwania dla: AMBIENT NOISE - MOST Wiedzy

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Wyniki wyszukiwania dla: AMBIENT NOISE

Wyniki wyszukiwania dla: AMBIENT NOISE

  • Low-frequency noise in Au-decorated graphene–Si Schottky barrier diode at selected ambient gases

    Publikacja
    • J. Smulko
    • K. Drozdowska
    • A. Rehman
    • T. Welearegay
    • L. Österlund
    • S. Rumyantsev
    • G. Cywiński
    • B. Stonio
    • A. Krajewska
    • M. Filipiak
    • P. Sai

    - APPLIED PHYSICS LETTERS - Rok 2023

    We report results of the current–voltage characteristics and low-frequency noise in Au nanoparticle (AuNP)-decorated graphene–Si Schottky barrier diodes. Measurements were conducted in ambient air with addition of either of two organic vapors, tetrahydrofuran [(CH2)4O; THF] and chloroform (CHCl3), as also during yellow light illumination (592nm), close to the measured particle plasmon polariton frequency of the Au nanoparticle...

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  • Temperature influence on tire/road noise evaluated by the drum method

    Ambient air and road surface temperatures substantially affect the road vehicle noise emission. The temperature influence on tire/road noise depends mainly on tire-road combination. It is different for dense and porous pavements, for bituminous and cement ones. It differs also depending on tires. The correction procedures for temperature effect are still under consideration and preparation. Laboratory experiment was prepared to...

  • Numerical Model of Surface and Quasi-Spherical Sea Noise and Its Application to Analysis of DIFAR Systems

    Various types of passive sonar systems are used to detect submarines. These activities are complex and demanding. Therefore, computer simulations are most often used at the design stage of these systems. For this reason, it is also necessary to simulate the acoustic ambient noise of the sea. The article proposes a new numerical model of surface and quasi-spherical sea noise and presents its statistical parameters. The results of...

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  • Generation-recombination and 1/f noise in carbon nanotube networks

    Publikacja
    • A. Rehman
    • A. Krajewska
    • B. Stonio
    • K. Pavlov
    • G. Cywinski
    • D. Lioubtchenko
    • W. Knap
    • S. Rumyantsev
    • J. Smulko

    - APPLIED PHYSICS LETTERS - Rok 2021

    The low-frequency noise is of special interest for carbon nanotubes devices, which are building blocks for a variety of sensors, including radio frequency and terahertz detectors. We studied noise in as-fabricated and aged carbon nanotube networks (CNNs) field-effect transistors. Contrary to the majority of previous publications, as-fabricated devices demonstrated the superposition of generation-recombination (GR) and 1/f noise...

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  • Temperature influence on tyre/road noise of selected tyres

    Publikacja

    Air and road temperatures substantially affect road vehicle noise emission. The temperature influence on tyre/road noise depends mainly on tyre-road combination. It is different for dense and porous pavements, for bituminous and cement ones. It differs also depending on tyres. The correction procedures for temperature effect are still under consideration and preparation. Tyre/road noise measurements using CPX method were performed...

  • Tracking of the broadband source of the underwater noise in the very shallow water conditions

    Publikacja

    The paper contains the result s, both theoretical and experimental , connected with the tracking of the underwater noise source as small ships, pontoon , diver and so on. The pro blem of security in the shallow water area is the challenge for underwater acousticians. In this paper there is take n into account the detection of the sources that move on the surface of the sea or underwater in shallow...

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  • SAMPLE-AND-HOLDING METHOD FOR GAS SENSING APPLIED FOR RESISTANCE GAS SENSORS

    Publikacja

    - Rok 2014

    The DC resistance of a Taguchi gas sensor is influenced by the ambient gas. To improve the selectivity and sensitivity of a sensor the fluctuation enhanced sensing (FES) was used. The paper proposes a novel methodology of utilizing FES technique that sample composition of an ambient atmosphere and hold it for further processing (sample-and-holding technique). The method uses the heated gas sensor to sample an ambient atmosphere...

  • Analytical fluctuation enhanced sensing by resistive gas sensors

    Publikacja
    • R. Macku
    • J. Smulko
    • P. Koktavy
    • M. Trawka
    • P. Sedlak

    - SENSORS AND ACTUATORS B-CHEMICAL - Rok 2015

    Resistance fluctuations across polarised resistive gas sensors were studied in detail to evaluate sensor working conditions for detecting methane and ammonia at various concentrations. The 1/f noise component typically dominates other noise sources up to a few kHz and can be utilised to improve gas selectivity when compared with measurements of the sensor DC resistance. The Arrhenius plot was created and the activation energy for...

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  • Wave Method for Structural Health Monitoring: Testing Using Full-Scale Shake Table Experiment Data

    Publikacja

    - JOURNAL OF STRUCTURAL ENGINEERING-ASCE - Rok 2017

    An algorithm of the wave method for structural health monitoring (SHM) is tested and calibrated using shake table experiment data of a full-scale, seven-story, reinforced-concrete building slice. The method is based on monitoring changes in the velocity of waves propagating vertically through the structure, identified by least-squares (LSQ) fit of beam models. The experiment was conducted by a team from the University of California,...

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  • Ambient vibrations - footbridge over the Kolibkowski Stream in Gdynia, span P2

    Dane Badawcze
    open access

    Ambient vibration tests carried out on the P2 span of the footbridge over the Kolibkowski Stream. The research was carried out using a set of 14 acceleration sensors - MEMS accelerometers TE 4332M3-002 and TE 4312M3-002, which allowed for simultaneous measurement and recording of 20 acceleration channels. These sensors are characterized by a natural...

  • Ambient vibrations - footbridge over the Kolibkowski Stream in Gdynia, span P3

    Dane Badawcze
    open access

    Ambient vibration tests carried out on the P3 span of the footbridge over the Kolibkowski Stream. The research was carried out using a set of 14 acceleration sensors - MEMS accelerometers TE 4332M3-002 and TE 4312M3-002, which allowed for simultaneous measurement and recording of 20 acceleration channels. These sensors are characterized by a natural...

  • Electrical and noise responses of carbon nanotube networks enhanced by UV light for detection of organic gases (ethanol, acetone)

    Dane Badawcze
    open access

    Carbon nanotube networks of different optical transparencies were investigated via resistance and 1/f noise measurements for detection of ethanol and acetone. The sensor resistive and noise responses were collected for dark and UV-assisted conditions, revealing the improvement in sensor sensitivity and limit of detection after applying UV light (275...

  • Advanced operating methods

    Publikacja

    - Rok 2020

    Selected operating methods of resistive gas sensors were presented. The methods utilize flicker noise (1/f noise), which gives additional information about ambient gas when compared with the recorded changes of DC resistance only. Methods of flicker noise measurements were outlined. Recently developed prototype gas sensors comprising golden nanoparticle functionalized with organic ligands can generate intense flicker noise induced...

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  • Metody usuwania zakłóceń podczas pomiarów polowych widm Ramana

    Publikacja

    W pracy zostały scharakteryzowane źródła zakłóceń występujące podczas pomiarów widm Ramana w warunkach polowych. Zaprezentowano wpływ czasu integracji na jakość rejestrowanych widm w przypadkach, gdy szumy własne spektrometru mają składową typu 1/f, dominującą w zakresie małych częstotliwości. Przedstawiono także wyniki uzyskane podczas pomiarów z detekcją synchroniczną, stosowaną w przenośnych spektrometrach Ramana, w pomiarach...

  • Method of selecting the LS-SVM algorithm parameters in gas detection process

    In this paper we showed the method of resistive gas sensors data processing. The UV irradiation and temperature modulation was applied to improve gas sensors’ selectivity and sensitivity. Noise voltage across the sensor’s terminals (proportional to its resistance fluctuations) was recorded to estimate power spectral density. This function was an input data vector for LS-SVM (least squares – support vector machine) algorithm, which...

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  • Fluctuation enhanced gas sensing with WO3-based nanoparticle gas sensors modulated by UV light at selected wavelengths

    Publikacja

    - SENSORS AND ACTUATORS B-CHEMICAL - Rok 2016

    The sensitivity and selectivity of WO3-based gas sensors can be enhanced by UV-irradiation-induced modulation, especially if different wavelengths are employed. We used fluctuation-enhanced gas sensing, based on measurements of resistance fluctuations in the gas sensor, to study the effects of such modulation on the noise intensity for ambient atmospheres of synthetic air without and with additions of small amounts of ethanol,...

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  • Metody usuwania zakłóceń podczas pomiarów polowych widm Ramana

    W pracy zostały scharakteryzowane źródła zakłóceń występujące podczas pomiarów widm Ramana w warunkach polowych oraz sposoby redukcji ich wpływu na jakość rejestrowanych widm. Zaprezentowano wpływ czasu integracji na jakość rejestrowanych widm w przypadkach, gdy szumy własne spektrometru mają składową typu 1/f, dominującą w zakresie małych częstotliwości. Przedstawiono także wyniki uzyskane podczas pomiarów z detekcją synchroniczną,...

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  • UV Light-Modulated Fluctuation-Enhanced Gas Sensing by Layers of Graphene Flakes/TiO2 Nanoparticles

    Publikacja

    - Journal of Sensors - Rok 2020

    We present experimental results of fluctuation-enhanced gas sensing by low-cost resistive sensors made of a mixture of graphene flakes and TiO2 nanoparticles. Both components are photocatalytic and activated by UV light. Two UV LEDs of different wavelengths (362 and 394 nm) were applied to modulate the gas sensing of the layers. Resistance noise was recorded at low frequencies, between 8 Hz and 10 kHz. The sensors’ response was...

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  • Organic Vapor Sensing Mechanisms by Large-Area Graphene Back-Gated Field-Effect Transistors under UV Irradiation

    Publikacja
    • K. Drozdowska
    • A. Rehman
    • P. Sai
    • B. Stonio
    • A. Krajewska
    • M. Dub
    • J. Kacperski
    • G. Cywiński
    • M. Haras
    • S. Rumyantsev... i 3 innych

    - ACS Sensors - Rok 2022

    The gas sensing properties of graphene back-gated field-effect transistor (GFET) sensors toward acetonitrile, tetrahydrofuran, and chloroform vapors were investigated with the focus on unfolding possible gas detection mechanisms. The FET configuration of the sensor device enabled gate voltage tuning for enhanced measurements of changes in DC electrical characteristics. Electrical measurements were combined with a fluctuation-enhanced...

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  • An NO2 sensor based on WO3 thin films for automotive applications in the microwave frequency range

    Publikacja
    • A. Paleczek
    • D. Grochala
    • K. Staszek
    • S. Gruszczyński
    • E. Maciak
    • Z. Opilski
    • P. Kałużyński
    • M. Wójcikowski
    • T. Cao
    • A. Rydosz

    - SENSORS AND ACTUATORS B-CHEMICAL - Rok 2023

    A microwave system dedicated to the detection of nitrogen dioxide in the harsh environment of the Norway highways is proposed. An optimized transmission line type of sensor coated with a tungsten trioxide thin film that changes its electrical properties under NO2 gas exposure is developed. The sensors' response (S) is given in °/GHz and it is calculated based on wideband measurements. The advantage of wideband measurements in comparison...

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  • POSSIBILITIES OF ELECTRICAL ENERGY GENERATION IN PHOTOVOLTAIC SYSTEMS INSTALLED IN CENTRAL EUROPE

    Publikacja

    - Rok 2013

    Nowadays, fossil fuels are the main sources of energy from which electricity is obtained. But these sources will not last forever, so in due course renewable energies will have to replace them in this role. One of these new sources is solar energy. To generate electricity from sunlight, solar (photovoltaic - PV) cells and modules are used. The increasing interest in PV cells and modules worldwide is due mainly to the fact that...

  • Signal conditioning for examination of shallow-water acoustic noise correlation properties

    Publikacja

    The article describes the process of signal conditioning for examination of acoustic noise correlation properties in shallow water. Knowledge of these properties is very important for the design processes of passive and active hydroacoustic systems. This paper focuses on the above issue from the point of view of passive sonar. In sonar systems, signal processing algorithms operate on both useful acoustic signals, and accompanying...

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