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Wyszukujesz frazę "Eid, E. A." wg kryterium: Autor


Wyświetlanie 1-7 z 7
Tytuł:
An Approach to Design Broadband Air Backed Piezoelectric Sensor
Autorzy:
Ali, M. G. S.
Elsayed, N. Z.
Eid, E. A.
Powiązania:
https://bibliotekanauki.pl/articles/176360.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
piezoelectric
equivalent circuits
impulse response
frequency response
matching layers
z-transform
Opis:
In this work, an approach to the design of broadband thickness-mode piezoelectric transducer is presented. In this approach, simulation of discrete time model of the impulse response of matched and backed piezoelectric transducer is used to design high sensitivity, broad bandwidth, and short-duration impulse response transducers. The effect of matching the performance of transmitting and receiving air backed PZT-5A transducer working into water load is studied. The optimum acoustical characteristics of the quarter wavelength matching layers are determined by a compromise between sensitivity and pulse duration. The thickness of bonding layers is smaller than that of the quarter wavelength matching layers so that they do not change the resonance peak significantly. Our calculations show that the −3 dB air backed transducer bandwidth can be improved considerably by using quarter wavelength matching layers. The computer model developed in this work to predict the behavior of multilayer structures driven by a transient waveform agrees well with measured results. Furthermore, the advantage of this this model over other approaches is that the time signal for optimum set of matching layers can be predicted rapidly.
Źródło:
Archives of Acoustics; 2015, 40, 1; 3-10
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Simulation for Detecting Nonlinear Echoes from Microbubbles Packets
Autorzy:
Ali, M. G. S.
Elsayed, N. Z.
Eid, E. A.
Powiązania:
https://bibliotekanauki.pl/articles/177697.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
microbubbles packets
harmonic component
acoustic
radial dynamic
pressure spectrum
Opis:
This work presents a simulation of the response of packets of microbubbles in an ultrasonic pulse-echo scan line. Rayleigh-Plesset equation has been used to predict the echo from numerically obtained radial dynamics of microbubbles. Varying the number of scattering microbubbles on the pulse wave form has been discussed. To improve microbubble-specific imaging at high frequencies, the subharmonic and second harmonic signals from individual microbubbles as well as microbubbles packets were simulated as a function of size and pressure. Two different modes of harmonic generation have been distinguished. The strength and bandwidth of the subharmonic component in the scattering spectrum of microbubbles is greater than that of the second harmonic. The pressure spectra provide quantitative and detailed information on the dynamic behaviour of ultrasound contrast agent microbubbles packet.
Źródło:
Archives of Acoustics; 2015, 40, 2; 151-157
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A topological model to assess networks connectivity and reliability
Autorzy:
Eid, M.
Hami-EL, A.
Souza de Cursi, E.
Powiązania:
https://bibliotekanauki.pl/articles/2069197.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
network
connectivity
failure
reliability
availability
Opis:
The acceleration of the interconnectivity of networks of all sorts brings to the front scene the issue of networks performance measure. Recently, one observed an accelerating course towards quantitative probabilistic models to describe and assess networks’ Connectivity, as being the main vector of performance. However, modelling realistic networks is still far from being satisfactorily achieved using quantitative probabilistic models. On the other hand, little room had been lift to exploring the potential of topological models to develop qualitative and semi- quantitative models in order to assess networks connectivity. In this paper, we are exploring the potential of the topological modelling. The proposed model is based on describing the nodepair connectivity using binary scalars of different orders (tensors). Preliminary results of our explorations sounded very promoting.
Źródło:
Journal of Polish Safety and Reliability Association; 2013, 4, 2; 167--178
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of carbon stock in the sediment of two mangrove species, Avicennia marina and Rhizophora mucronata, growing in the Farasan Islands, Saudi Arabia
Autorzy:
Eid, E.M.
Khedher, K.M.
Ayed, H.
Arshad, M.
Moatamed, A.
Mouldi, A.
Powiązania:
https://bibliotekanauki.pl/articles/2079280.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
carbon stock
sediment
Avicennia marina
mangrove ecosystem
Rhizophora mucronata
arid region
Saudi Arabia
Opis:
The aim of this study was to conduct the first comprehensive evaluation of carbon stock in the sediments of Avicennia marina (black mangrove) and Rhizophora mucronata (red mangrove) along the coastline of an arid region (Farasan Islands, Saudi Arabia). Such information is necessary for the development of any management plan for the mangrove ecosystems along the Saudi Red Sea islands and provide a rationale for the restoration of mangrove forests in Saudi Arabia. A. marina and R. mucronata locations showed significant (P < 0.001) differences in sediment bulk density (SBD) and sediment organic carbon (SOC) concentration with higher mean values for both in the sediments of A. marina. Considering the whole depth of sediment sampled (0–50 cm), the highest value of SOC stock (12.3 kg C m−2) was recorded at A. marina locations and the lowest (10.8 kg C m−2) at R. mucronata locations. Thus, the SOC stock of A. marina was greater than that of R. mucronata by 114.3%. Consequently, considering the rate of carbon sequestration and the area of mangrove forests (216.4 ha), the total carbon sequestration potential of mangroves in the Farasan Islands ranged between 10.3 Mg C yr−1 and 11.8 Mg C yr−1 for R. mucronata and A. marina locations, respectively. Thus, it is necessary to protect and restore these ecosystems for the sequestration of carbon and for their other valuable ecosystem services.
Źródło:
Oceanologia; 2020, 62, 2; 200-213
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Critical infrastructure preparedness : cascading of disruptions considering vulnerability and Dependency
Autorzy:
Eid, M.
Hakkarainen, T.
Terhi, K.
Souza-Cursi-de, E.
El-Hami, A.
Powiązania:
https://bibliotekanauki.pl/articles/2069144.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
CIP
cascade
disruption
vulnerability
dependency
model
simulation
stochastic
Poisson
probability
Opis:
Critical Infrastructures’ disruptions may result in crises of unacceptable outcomes in modern societies. Thus, it is important to develop models that allow describing CIs’ disruptions and their propagation characteristics. CI disruptions depend on both the type of the threat and on the nature of the CIs’ mutual dependencies. A model describing the cascade of disruptions should, then, be able to consider the CI-threat vulnerability and the CI-CI dependency. The paper presents a model where cascades are exactly described using an integral equation. The integral equation admits an analytical solution if the occurrence probability distribution functions (pdf) of the disruptions obey Stochastic Poisson Processes (SPP). The introduction of the “vulnerability to the threat” and the “CIs’ (inter)dependencies” is carried out with the help of time constant factors called: “vulnerability strain factor” and “disruption strain factor”, respectively. An academic case is presented in order to demonstrate the applicability of the model and illustrate some interesting features of the model. A complete set of numerical applications will be published separately.
Źródło:
Journal of Polish Safety and Reliability Association; 2016, 7, 1; 61--66
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of the carbon sequestration capacity of arid mangroves along nutrient availability and salinity gradients along the Red Sea coastline of Saudi Arabia
Autorzy:
Shaltout, K.H.
Ahmed, M.T.
Alrumman, S.A.
Ahmed, D.A.
Eid, E.M.
Powiązania:
https://bibliotekanauki.pl/articles/48145.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
carbon sequestration
coastal wetland
mangrove
climate change
nutrient availability
salinity gradient
Red Sea
Saudi Arabia
Źródło:
Oceanologia; 2020, 62, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Critical Infrastructures Protection (CIP) : coupled modelling for threats and resilience
Autorzy:
Eid, M.
El-Hami, A.
Souza de Cursi, E.
Kołowrocki, K.
Kuligowska, E.
Soszyńska-Budny, J.
Powiązania:
https://bibliotekanauki.pl/articles/2069190.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
Critical Infrastructures Protection
CIP
resilience
robustness
failure
dynamic
model
crisis
management
Opis:
Critical Infrastructure Protection (CIP) requires the development of models and tools able to describe and simulate the threats’ and the Critical Infrastructure’s (CI) dynamic behaviour. However, these modelling activities are very often carried out separately for threats and for CI behaviour. An effective assessment of the CI’s resilience and preparedness requires real coupled models of threats dynamic and CI’s one. The authors develop some basic ideas about coupled modelling in the sense of coupling the dynamics of the threat with that of the CIs, within a stochastic modelling approach. Such coupled dynamic models would enhance the effectiveness of our capabilities to assess CI’s resilience and to help in decision making for crisis management.
Źródło:
Journal of Polish Safety and Reliability Association; 2015, 6, 1; 85--94
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-7 z 7

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