Wyniki wyszukiwania - BazTech

1

Relations between ion signal and flame propagation in cylinder of a rapid compression machine

Fiedkiewicz Łukasz, Pielecha Ireneusz

Combustion Engines

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2019

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R. 58, nr 4

264--268

EN

Internal combustion engine diagnostics using traditional methods of cylinder pressure signal processing limits the amount of information available about the combustion process. It is necessary to conduct research in order to obtain more precise information - in-creasing the combustion process diagnosis potential. One such suggestion is the use of an ionization signal and an attempt to link it to the flame development during combustion of gaseous fuels. The article attempts to identify such a relationship using a rapid compression machine due to optical access it provides to the combustion chamber. As a result of the research, the relationships between the ionization voltage (chemical and thermal) of the first combustion phase and the corresponding flame development rates were determined. A relatively high coefficient of determination value was obtained for both relations, which indicates the possibility of obtaining diagnostic information about the combustion process from the ionization signal.

2

Application of Ion Current Measurement to Identification of Combustion Parameters in a Homogeneous Charge Compression Ignition Engine

Hunicz J., Filipek P., Sobiesiak A.

Metrology and Measurement Systems

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2018

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Vol. 25, nr 1

223--234

EN

This study examines the application of ion current measurements to the identification of heat release parameters inside the combustion chamber of a homogeneous charge compression ignition (HCCI) engine fuelled with gasoline. HCCI combustion was achieved with the use of exhaust gas trapping. Combustion parameters derived from the in-cylinder pressure and ion current measurements were compared and analysed. Ion current measurements were accomplished using the existing spark plug and a dedicated electronic circuit. The experiments were performed at a variable excess air ratio and a variable amount of trapped residuals. The results showed a good correlation between peak values of the ion current and heat release rate, except for the cases where a fuel-rich mixture was burnt. The computed ion current integral over the volume of the combustion chamber showed a good agreement with the heat released in the combustion chamber, however this parameter was found to be affected by the amount of trapped residuals. Combustion timing characteristic values computed using heat release and ion current were found to be correlated, however the relationship was not linear.

3

Transistor Effect in the Cochlear Amplifier

Kiełczyński P., Szalewski M.

Archives of Acoustics

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2014

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Vol. 39, No. 1

117--124

EN

The paper presents a new electromechanical amplifying device i.e., an electromechanical biological transistor. This device is located in the outer hair cell (OHC), and constitutes a part of the Cochlear amplifier. The physical principle of operation of this new amplifying device is based on the phenomenon of forward mechanoelectrical transduction that occurs in the OHC’s stereocilia. Operation of this device is similar to that of classical electronic Field Effect Transistor (FET). In the considered electromechanical transistor the input signal is a mechanical (acoustic) signal. Whereas the output signal is an electric signal. It has been shown that the proposed electromechanical transistor can play a role of the active electromechanical controlled element that has the ability to amplify the power of input AC signals. The power required to amplify the input signals is extracted from a battery of DC voltage. In the considered electromechanical transistor, that operates in the amplifier circuit, mechanical input signal controls the flow of electric energy in the output circuit, from a battery of DC voltage to the load resistance. Small signal equivalent electrical circuit of the electromechanical transistor is developed. Numerical values of the electrical parameters of the equivalent circuit were evaluated. The range, which covers the levels of input signals (force and velocity) and output signals (voltage, current) was determined. The obtained data are consistent with physiological data. Exemplary numerical values of currents, voltages, forces, vibrational velocities and power gain (for the assumed input power levels below 1 picowatt (〖10〗^(-12) W), were given. This new electromechanical active device (transistor) can be responsible for power amplification in the cochlear amplifier in the inner ear.

4

Nanopory : budowa, właściwości, modele, zastosowania

Stachiewicz A., Molski A.

Wiadomości Chemiczne

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2013

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[Z] 67, 3-4

277--302

EN

Nanopores are small (1–100 nm diameter) holes/channels formed in biological membranes (Fig. 1) or fabricated in synthetic materials (Fig. 2). Permeation of ions and small molecules through nanopores is common in biological systems. The first experiments where nanopores were used as single-molecule sensors were performed in the 90s [1, 2]. The detection principle is based on a monitoring of an ionic current passing through a nanopore as an electric field is applied across the membrane. Electrically charged particles (e.g. DNA ) move in the electric field and block the ionic current as they pass through the nanopore. A sudden drop of the ionic current signals a single-molecule translocation event (Fig. 3–5). Nanopore sensors can give an information about the analyte: its size, structure and bonds stability. Today, a major topic of interest is the possibility of nanopore DNA sequencing. In this work we present an introduction to nanopore technology and to current research related to potential nanopore applications. First, we describe biological and synthetic nanopores: their structure and methods of fabrication. Next, different modes of nanopore experiments are presented. In the third section, we focus on theoretical models and simulations of nanopores. Finally, we present future perspectives for applications with particular reference to DNA sequencing.

5

Analiza wrażliwościowa spektrometru mas z innowacyjnym układem polaryzacji źródła elektronów

Sikora J., Szczepaniak L.

Pomiary Automatyka Kontrola

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2012

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R. 58, nr 3

256-259

PL

Praca prezentuje wyniki badań wrażliwości spektrometru mas z nowatorskim układem polaryzacji źródła elektronów, zapewniającym niezależny dobór natężenia prądu emisji elektronowej i napięcia przyśpieszającego elektrony. Dzięki takiemu rozwiązaniu możliwe jest wyznaczenie wrażliwości natężenia prądu jonowego niezależnie względem natężenia prądu emisji elektronowej i napięcia przyśpieszającego elektrony. Badania objęły również pozostałe charakterystyki spektrometru mas oraz wrażliwości natężenia prądu jonowego względem ciśnienia i napięcia przyspieszającego jony. Wyniki potwierdzają zalety nowego rozwiązania w spektrometrze mas.

EN

The sensitivity measurement results of a mass spectrometer (Fig. 1) with an innovative biasing system in an electron source [1] are presented. The biasing system ensures that an accelerating voltage and an electron emission current are independent of each other. Owing to that, the sensitivity of an ion current versus the electron emission current (Fig. 2), and independently versus the electron accelerating voltage (Fig. 3) can be determined. The researches included the determination of the mass spectrometer characteristics and sensitivity of the ion current in function of a pressure (Fig. 4.) and the ion current in function of an ion accelerating voltage (Fig. 5, Fig. 6). The results confirm that new biasing system is highly suitable for the mass spectrometer.