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Wyświetlanie 1-11 z 11
Tytuł:
The Cancer Cell Plasma Membrane Potentials As Energetic Equivalents to Astrophysical Properties
Autorzy:
Persinger, M. A.
Lafrenie, R. M.
Powiązania:
https://bibliotekanauki.pl/articles/411648.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
kT boundary
magnetic energy
cancer cell
entropy
noise band
Hubble's parameter
Opis:
The primary physical and chemical parameters that define the hypopolarized plasma cell membrane of malignant (cancer) cells compared to non-malignant cells reflect universal characteristics. The median value for the resting membrane potential is the constant for the Nernst equation without reference to discrepancies in ion concentrations and is identical to Boltzmann energies at 37 °C. The threshold energy defining space-time converges with access to entropic processes that are reflected in the morphology of cancer cells and tumors. Slowing of growth in cancer cell lines but not normal cells following exposure to weak (~1 to 10 μT) patterned magnetic fields occurs when the energy induced within the cell corresponds to the energy equivalent of the hypopolarized membrane potential. The optimal temporal parameters for the efficacy of these fields can be derived from Hubble‟s parameter and the transform function for “noise” or “random” patterns within the system. Quantitative solutions and experimental data indicate that the cancer cell may be dominated by entropic process that can be attenuated or blocked by temporally-structured applied magnetic fields whose intensity matches the increment of energy associated with this threshold.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 17, 1; 67-77
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Irregularity of static working states of ship combustion piston engine
Autorzy:
Chłopek, Z.
Piaseczny, L.
Powiązania:
https://bibliotekanauki.pl/articles/259660.pdf
Data publikacji:
2006
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
silniki spalinowe
warunki statyczne
zakłócenia
hałas
hałas niewspółzależny
combustion piston engine
static conditions
statistics
broad-band noise
uncorrelated noise
Opis:
Variability of static working conditions of combustion engine in the range of higher frequencies has character of noise resulting from phenomena not taken directly into account in test program as well as from features of measuring systems. Knowledge of features of the noise contained in observed static signals is important for determining the representative values taken as static and slow-changeable in conditions of unavoidable disturbances. The tests in question were carried out in the static working conditions of a 6AL 20/24 Sulzer diesel engine, determined by the torque Me = 4.33 kNm and the rotational speed n = 660 min-1. The following quantities characterizing emission of pollutants contained in exhaust gas in the conditions described by the engine working point : torque, rotational speed and concentrations of carbon oxide, hydrocarbons and nitrogen oxides, were selected for analyses. The tests were performed in the domains of time, process values and frequency. It was stated that the observed runs of the noise generated by phenomena not directly accounted for in combustion engine static test program and by measuring systems, had mainly the character of uncorrelated broad-band normal noise. The results justify a.o. correctness of averaging the measurement results obtained in static conditions as well as synchronous averaging in steady conditions.
Źródło:
Polish Maritime Research; 2006, 2; 9-14
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical study of back-to-back avalanche photodiodes for dual-band infrared applications
Autorzy:
Manyk, Tetiana
Majkowycz, Kinga
Rutkowski, Jarosław
Martyniuk, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/2204171.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
IR detectors
HgCdTe avalanche photodiodes
excess noise
gain
dual-band detectors
Opis:
The dual-band avalanche photodiode (APD) detector based on a HgCdTe material system was designed and analysed in detail numerically. A theoretical analysis of the two-colour APD intended for the mid wavelength infrared (MWIR) and long wavelength infrared (LWIR) ranges was conducted. The main purpose of the work was to indicate an approach to select APD structure parameters to achieve the best performance at high operating temperatures (HOT). The numerical simulations were performed by Crosslight numerical APSYS platform which is designed to simulate semiconductor optoelectronic devices. The current-voltage characteristics, current gain, and excess noise analysis at temperature T = 230 K vs. applied voltage for MWIR (U = 15 V) and LWIR (U = –6 V) ranges were performed. The influence of low and high doping in both active layers and barrier on the current gain and excess noise is shown. It was presented that an increase of the APD active layer doping leads to an increase in the photocurrent gain in the LWIR detector and a decrease in the MWIR device. The dark current and photocurrent gains were compared. Photocurrent gain is higher in both spectral ranges.
Źródło:
Opto-Electronics Review; 2023, 31, 2; art. no. e145093
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Propozycje rozwiązań filtrowania sygnału w elektronicznych systemach przekazywania dźwięku
Proposals for signal filtering solutions in electronic sound transmission systems
Autorzy:
Młyński, Rafał
Kozłowski, Emil
Morzyński, Leszek
Swidziński, Adam
Powiązania:
https://bibliotekanauki.pl/articles/2202842.pdf
Data publikacji:
2021
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
hałas
filtry pasmowe
filtry oktawowe
dźwięk
ochronniki słuchu
noise
band-pass filters
octave-band filters
sound
hearing protectors
Opis:
Właściwa percepcja dźwięków w środowisku pracy, najczęściej dźwiękowych sygnałów bezpieczeństwa, ale również ostrzeżeń słownych od współpracowników, wpływa na zwiększenie stopnia bezpieczeństwa przebywania w miejscu pracy. Istotne jest zatem, aby właściwości dźwięków przekazywanych z wykorzystaniem systemów elektronicznych były jak najlepiej dostosowane do możliwości ich odbioru przez pracownika – z uwzględnieniem warunków akustycznych panujących w miejscu użytkowania takich systemów. Właściwości dźwięku można dostosować poprzez wpływ na charakterystykę częstotliwościową sygnału, tj. jego filtrowanie. Celem artykułu jest przedstawienie propozycji rozwiązań, które mogłyby być użyte w elektronicznym systemie przekazywania dźwięków pracownikowi, umożliwiającym filtrowanie sygnału w pasmach częstotliwości. Przeanalizowano wymagania dotyczące właściwości pomiarowych filtrów pasmowych o szerokości oktawy. Przeprowadzono implementację filtrów o częstotliwościach środkowych z zakresu od 125 Hz do 8 kHz z wykorzystaniem filtrów cyfrowych w procesorze dźwięku. Duży stopień zgodności charakterystyk, które uzyskano w zrealizowanym rozwiązaniu, ze znormalizowanymi charakterystykami pomiarowymi wskazuje na przydatność zaproponowanego rozwiązania do wykorzystania w systemach przekazywania dźwięku pracownikowi.
Proper perception of sounds in the work environment, most often auditory danger signals, but also verbal warnings from co-workers, increases the degree of safe stay in the workplace. Hence, it is important that the properties of the sound transmitted to an employee with the use of electronic systems are as best as possible adapted to the possibility of its perception by that employee, taking into account the acoustic conditions in the place of use of such systems. Adjusting the sound properties can be realized by influencing the frequency response of the signal, i.e. its filtering. The aim of the article is to propose solutions that could potentially be used in an electronic system of transmitting sound to an employee, enabling filtering of the signal in frequency bands. The requirements for the properties of measurement octave-wide band filters were analysed. The implementation of filters with a centre frequency ranging from 125 Hz to 8 kHz with the use of digital filters in the sound processor was carried out. The high degree of compliance of the characteristics obtained in the implemented solution with the standardized measurement characteristics indicates the suitability of the proposed solution for use in sound transmission systems to an employee.
Źródło:
Bezpieczeństwo Pracy : nauka i praktyka; 2021, 11; 22-27
0137-7043
Pojawia się w:
Bezpieczeństwo Pracy : nauka i praktyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance Comparison of Modified BPSK-OFDM and QFSK-OFDM in PLC Channel Noise
Autorzy:
Bolaji, Abiola G.
Shongwe, Thokozani
Powiązania:
https://bibliotekanauki.pl/articles/1844463.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
narrow-band Interference
impulsive noise
power line communications
BPSK-OFDM
QFSK-OFDM
Opis:
The article describes and compares two OFDM based communications schemes for reducing the effects of the combination of Narrowband Interference (NBI) and Impulsive Noise (IN), which are noise types typical in Power Line Communication (PLC). The two schemes are Modified BPSK-OFDM (called MBPSK, for brevity) and QFSK-OFDM (called QFSK, for brevity), which are non-conventional OFDM schemes. We give a description of the two schemes, showing how they are derived and also show their similarities and eventually compare their performances. Performance simulation results, in terms of bit error rate, are given to compare the systems under the effect of IN and NBI. The popular Middleton Class A model is used for modelling IN. The results show that MBPSK scheme outperforms the QFSK scheme in terms of minimum distance, and hence in terms of bit error probability when no preprocessing is performed. However, under clipping/nulling, both schemes eventually reach the bit error rate floor.
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 4; 599-605
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
64 channel neural recording amplifier with tunable bandwidth in 180 nm CMOS technology
Autorzy:
Gryboś, P.
Kmon, P.
Żołądź, M.
Szczygieł, R.
Kachel, M.
Lewandowski, M.
Błasiak, T.
Powiązania:
https://bibliotekanauki.pl/articles/220527.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
neurobiological measurements
low noise amplifier
neural recording
band-pass filter
multichannel ASIC
Opis:
This paper presents the design and measurements of low-noise multichannel front-end electronics for recording extra-cellular neuronal signals using microelectrode arrays. The integrated circuit contains 64 readout channels and is fabricated in CMOS 180 nm technology. A single readout channel is built of an AC coupling circuit at the input, a low-noise preamplifier, a band-pass filter and a second amplifier. In order to reduce the number of output lines, the 64 analog signals from readout channels are multiplexed to a single output by an analog multiplexer. The chip is optimized for low noise and good matching performance and has the possibility of passband tuning. The low cut-off frequency can be tuned in the 1 Hz - 60 Hz range while the high cut-off frequency can be tuned in the 3.5 kHz - 15 kHz range. For the nominal gain setting at 44 dB and power dissipation per single channel of 220 žW, the equivalent input noise is in the range from 6 žV - 11 žV rms depending on the band-pass filter settings. The chip has good uniformity concerning the spread of its electrical parameters from channel to channel. The spread of the gain calculated as standard deviation to mean value is about 4.4% and the spread of the low cut-off frequency set at 1.6 Hz is only 0.07 Hz. The chip occupies 5×2.3 mm⊃2 of silicon area. To our knowledge, our solution is the first reported multichannel recording system which allows to set in each recording channel the low cut-off frequency within a single Hz with a small spread of this parameter from channel to channel. The first recordings of action potentials from the thalamus of the rat under urethane anesthesia are presented.
Źródło:
Metrology and Measurement Systems; 2011, 18, 4; 631-643
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Utilization of ASTER data in lithological and lineament mapping of the southern flank of the Central High Atlas in Morocco
Autorzy:
Errami, Maryam
Algouti, Ahmed
Algouti, Abdellah
Farah, Abdelouhed
Agli, Saloua
Powiązania:
https://bibliotekanauki.pl/articles/2204372.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
Amezri-Amassine area
PCA
Principal Component Analysis
band ratio
MNF
Minimum Noise Fraction
automatic lineament extraction
Amezri
Amassine
analiza głównych składowych
Opis:
Geological mapping undoubtedly plays an important role in several studies and remote sensing data are of great significance in geological mapping, particularly in poorly mapped areas situated in inaccessible regions. In the present study, Principal Component Analysis (PCA), Band Rationing (BR) and Minimum Noise Fraction (MNF) algorithms are applied to map lithological units and extract lineaments in the Amezri-Amassine area, by using multispectral ASTER image and global digital elevation model (GDEM) data for the first time. Following preprocessing of ASTER images, advanced image algorithms such as PCA, BR and MNF analyses are applied to the 9ASTER bands. Validation of the resultant maps has relied on matching lithological boundaries and faults in the study area and on the basis of pre-existing geological maps. In addition to the PCA image, a new band-ratio image, 4/6–5/8–4/5, as adopted in the present work, provides high accuracy in discriminating lithological units. The MNF transformation reveals improvement over previous enhancement techniques, in detailing most rock units in the area. Hence, results derived from the enhancement techniques show a good correlation with the existing litho-structural map of the study area. In addition, the present results have allowed to update this map by identifying new lithological units and structural lineaments. Consequently, the methodology followed here has provided satisfactory results and has demonstrated the high potential of multispectral ASTER data for improving lithological discrimination and lineament extraction.
Źródło:
Geologos; 2023, 29, 1; 1--20
1426-8981
2080-6574
Pojawia się w:
Geologos
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
1.28 Tbps DWDM optical network design using a dispersion compensating distributed Raman amplifier over S-band
Autorzy:
Gul, Baseerat
Ahmad, Faroze
Powiązania:
https://bibliotekanauki.pl/articles/2206823.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
dense wavelength division multiplexing
conventional single mode fibre
optical signal to noise ratio
stimulated Raman scattering
S-band
dispersion compensating fibre
Opis:
A 100 km long dense wavelength division multiplexed optical network design with a capacity of 1.28 Tbps is proposed in this paper. The novelty of this work is the use of a dispersion compensating fibre as a Raman amplifier in the S-band for a high-capacity dense wavelength division multiplexing network. The transmission is accomplished auspiciously in the wavelength range from 196 THz to 202. 35THz. The coupling of a Raman amplifier made the realisation of the S-band possible in the network, as the erbium-doped fibre amplifier is competent for amplification in C- and L-bands only. Further, a pump coupler is used for multiple pumping to enlarge the gain spectrum for a high-capacity optical network. The performance analysis of the network is carried out systematically in terms of bit error rate (BER), eye diagram, Q-factor, and optical signal to noise ratio (OSNR). The results demonstrate that the proposed set-up shows adequately low BER, sufficient Q-factor values, wide eye-opening, and commendable OSNR for all receiving channels.
Źródło:
Opto-Electronics Review; 2023, 31, 2; art. no. e146104
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Filter Based Impedance Tube for Selection of Technical Textile Materials
Opracowanie tuby impedancyjnej do pomiaru akustycznych właściwości materiałów tekstylnych
Autorzy:
Niresh, J.
Neelakrishnan, S.
Subha Rani, S.
Archana, N.
Powiązania:
https://bibliotekanauki.pl/articles/233003.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
impedance tube
low pass filter
band pass filter
LMS filter
noise reduction
tuba impedancyjna
filtr dolnoprzepustowy
filtr pasmowy
filtr LMS
redukcja szumów
Opis:
Measurement of the sound absorption coefficient using an impedance tube is prone to errors due to various reasons. Conventionally minimising the errors requires additional hardware or proper calibration of many components used for measurement. This paper proposes a new error correction mechanism using a filtering technique. A low cost impedance tube was designed, developed and its performance was compared with a commercially available high cost tube. The errors which arose during the measurement of the sound absorption coefficient were minimised using different types of filters (low pass, band pass, LMS filtering). The purpose of the filter is to eliminate unwanted signals or noise which occur during the processing of analogue signals in the experiment. The system proposed was tested using various porous and non-porous functional textile materials and the results validated. A significant reduction in error was obtained at all frequency ranges with digital filters.
Pomiar współczynnika pochłaniania dźwięku za pomocą tuby impedancyjnej jest podatny na błędy. Konwencjonalne minimalizowanie błędów wymaga dodatkowego sprzętu lub odpowiedniej kalibracji wielu komponentów używanych do pomiaru. W artykule zaproponowano nowy mechanizm korekcji błędów za pomocą techniki filtrowania. Zaprojektowano i opracowano stosunkowo tani sposób wykonania nowego rodzaju tuby impedancyjnej i porównano jej działanie z dostępną na rynku tubą. Błędy, które powstały podczas pomiaru współczynnika pochłaniania dźwięku zostały zminimalizowane za pomocą różnych rodzajów filtrów (dolnoprzepustowym, środkowoprzepustowym, filtracyjnym LMS). Celem zastosowania filtra było wyeliminowanie niepożądanych sygnałów lub szumów, które występują podczas przetwarzania sygnałów analogowych podczas eksperymentów. Proponowany system został przetestowany przy zastosowaniu różnych porowatych i nieporowatych funkcjonalnych materiałów tekstylnych. Na podstawie uzyskanych wyników stwierdzono, że za pomocą filtrów cyfrowych można uzyskać znaczącą redukcję błędów we wszystkich zakresach częstotliwości.
Źródło:
Fibres & Textiles in Eastern Europe; 2018, 1 (127); 89-93
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantitative Support for Convergence of Intrinsic Energies from Applied Magnetic Fields and “Noise” Fluctuations of Newton’s Gravitational Value within the Human Brain
Autorzy:
Persinger, M. A.
Saroka, K. S.
Powiązania:
https://bibliotekanauki.pl/articles/411636.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Newton’s G
“noise” fluctuations in G
gravitational-magnetic energy equivalents
cerebral magnetic field applications
QEEG
right hemisphere sensitivity
theta-alpha band activity
Opis:
When the energy within the mass of the human brain that is associated with the intrinsic range in fluctuations of the Gravitational Constant (G) is set equal to the energy from a magnetic field (B) within the cerebral volume and solved for B, a value in the order of 20 to 50 nT is obtained. Quantitative Electroencephalographic (QEEG) and sLORETA (Low Resolution Electromagnetic Tomography) analyses of cerebral cortical activity during exposure to a range of applied rotating, frequency-modulated, transcerebral (between the two temporal lobes) magnetic fields between < 1 nT and 7000 nT while volunteers sat within a darkened, quiet chamber were completed. There was marked enhancement of power within the 4 Hz to 10 Hz band within the right caudal (cuneus) hemisphere while the ~5 to 20 nT averaged strength magnetic fields were applied but no significant responses at lesser or greater intensities. These results suggest that a physical process coupled to the source of the fluctuation (~10-15 m3kg-1s-2) in G may interact with right hemispheric activity within the range at which gravity waves have been estimated to interact with Schumann frequencies generated between the earth and ionosphere.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 19, 2; 181-190
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An experimental identification of multipath effect in GPS positioning error
Autorzy:
Rumora, I.
Sikirica, N.
Filjar, R.
Powiązania:
https://bibliotekanauki.pl/articles/116056.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
Pseudo Random Noise (PRN)
accuracy
GPS positioning errors
multipath effect
Base-band Processing Domain (BPD)
Navigation Processing Domain
Global Positioning System (GPS)
Global Navigation Satellite System (GNSS)
Opis:
The analysis of the GPS multipath effects in maritime environment is constrained with the practice of traditional GPS receiver design, that prevents access to GPS signals in Base-band Processing Domain. Here we propose and validate a simple method for experimental identification of multipath effect in Navigation Processing Domain, based on spectral characterisation of time series of GPS positioning errors.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2018, 12, 1; 29-32
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-11 z 11

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