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Wyszukujesz frazę "Hussein, M.M.A." wg kryterium: Autor


Wyświetlanie 1-23 z 23
Tytuł:
Potential effects of abiotic factors on the abundance and distribution of the plankton in the Western Harbour, South-Eastern Mediterranean Sea, Egypt
Autorzy:
Heneash, A.M.M.
Tadrose, H.R.Z.
Hussein, M.M.A.
Hamdona, S.K.
Abdel-Aziz, N.
Gharib, S.M.
Powiązania:
https://bibliotekanauki.pl/articles/48656.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
plankton
zooplankton
distribution
Western Harbour
Mediterranean Sea
Egypt
abiotic factor
potential effect
abundance
physicochemical parameter
seasonal dynamics
Źródło:
Oceanologia; 2015, 57, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ability of magnetic field to protect wheat crops during storage
Autorzy:
Zein, D.M.
Hussein, A.
Powiązania:
https://bibliotekanauki.pl/articles/65988.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
The current research aimed to use non traditional methods to control some stored grain insects. The effects of 180 millitesla (mT) magnetic field (MF) for six different exposure periods (3 min, 30 min, 1 h, 12 h, 24 h and 48 h) on mortality (%) of two stored grain insects, Tribolium casteneum adults and Trogoderma granarium larvae, reduction in F1-progeny (%), seeds germination (%) and seed components (%) after 8 months storage period were studied under laboratory conditions. According to results, the mortality (%) of tested insects increased with increasing of MF time exposure. Trogoderma granarium was more resistant than T. casteneum in which mortality reached 56 and 75%, respectively 14 days after from exposure period. Without any negative effect on seeds germination (%) the MF was very effective in protecting stored wheat from insect infestation up to 8 months compared to non-magnetic seeds which became infested after 3 months of storage. Furthermore, the germination (%) was accelerated by 6 h compared to non-magnetic seeds. The MF level caused a slight increase in the percent of total carbohydrate, crude protein and ash while slightly decrease the percent of moisture, total fats and crude fiber.
Źródło:
Journal of Plant Protection Research; 2019, 59, 2
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical thermo-mechanical strength analysis of an IC engine component
Autorzy:
Ali, M. A. N.
Hussein, R. A.
Hussein, H. A.
Powiązania:
https://bibliotekanauki.pl/articles/2106442.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
analiza numeryczna
silnik spalinowy
naprężenie
trwałość zmęczeniowa
numerical analysis
IC engine piston
geometrical shape
thermo-mechanical strength
stress intensity
fatigue life
Opis:
This research investigates a thermo-mechanical strength of three geometrical shape designs of an internal combustion (IC) engine piston by a finite element analysis (FEA). FEA was performed using Solidworks software for modelling geometrical piston designs, and the models were imported into ANSYS software for thermo-mechanical fatigue simulation. The work focused on predicting high stress intensity and indicated the fatigue critical regions and life of the piston shape design. AL7075-T6 aluminium alloy was used as a piston material and thermo-mechanical fatigue simulation was conducted based on the experimental stress-number of cycles recorded data from literature. Analytical results showed the similarity of the critical failure positions to some real failures in the IC engine piston, and the shape design modification of the piston. Hence, this concept can be used to satisfy the IC engine design needs at low cost.
Źródło:
International Journal of Applied Mechanics and Engineering; 2021, 26, 3; 1--11
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stress–strain relationship of ductile materials and flexural behavior of ductile over-reinforced concrete beams
Autorzy:
Duhaim, Hussein M.
Mashrei, Mohammed A.
Powiązania:
https://bibliotekanauki.pl/articles/36058847.pdf
Data publikacji:
2022
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
ductile material
SFRC
SIFCON
UHPFRC
over-reinforced beam
flexural behavior
ductility
Opis:
This paper aimed to investigate the effect of using ductile materials in the compression zone on the flexural performance of over-reinforced concrete beams. In order to avoid brittle compression failure, partial replacement of concrete with ductile materials layer in the compression zone was used. Four over-reinforced concrete beams of size 120 × 180 × 1,300 mm were cast and tested under three-point loading conditions. The steel fibers reinforced concrete (SFRC), slurry infiltrated fiber concrete (SIFCON), and ultra-high performance fiber reinforced concrete (UHPFRC) were used as ductile materials. The flexural capacity of the beams, failure modes, crack patterns, load-deflection relationships, ductility index, and toughness were investigated. The results showed that using ductile materials in the compression zone is an effective technique to increase the ultimate load, ductility, and toughness by up to 52.46, 84.78 and 279.93%, respectively, compared to the reference beam. In addition, the failure mode changed from brittle to ductile failure. Noting that the use of SFRC layer enhanced the ductility of over-reinforced concrete beams more than using UHPFRC and SIFCON layers. Also, one of the main advantages of this technique is led to increase the tensile reinforcement ratio up to 8.548% without needing the compressive reinforcement. Thus, ductile composite beams with a high flexural capacity were generated using an economical amount of ductile materials.
Źródło:
Scientific Review Engineering and Environmental Sciences; 2022, 31, 4; 225-237
1732-9353
Pojawia się w:
Scientific Review Engineering and Environmental Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Relative Explosive Strength and Detonation Characteristics of Some Explosive Mixtures Containing Urea and Peroxides
Autorzy:
Hussein, A. K.
Zeman, S.
Suceska, M.
Jungova, M.
Powiązania:
https://bibliotekanauki.pl/articles/403797.pdf
Data publikacji:
2017
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
urea
hydrogen peroxide
perchlorate
nitrates
ballistic mortar
Explo5
Opis:
Several mixtures, based on urea, urea hydrogen peroxide complex (UHP), triacetone triperoxide (TATP) with some inorganic oxidants were studied by means of ballistics mortar with TNT as a reference standard. The detonation pressure, P, detonation velocity, D, detonation heat, Q, and volume of gaseous product at standard temperature and pressure conditions (STP condition) were calculated by the mean of Explo5 V6.3. The relatively high explosive strength of some samples relative to the TNT charge, focuses on the positive influence of hydrogen peroxide presence in these mixtures, with advantage in the form of its complex with urea (i.e. as UHP). This influence connects with hydroxi-radical in the mixture under its initiation (as the first intermediate of this initiation reaction).
Źródło:
Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa; 2017, 8, 3 (29); 23-32
2081-5891
Pojawia się w:
Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Changes in Atlantic water characteristics in the South-Eastern Mediterranean Sea as a result of natural and anthropogenic activities
Autorzy:
Said, M.A.
Gerges, M.A.
Maiyza, I.A.
Hussein, M.A.
Radwan, A.A.
Powiązania:
https://bibliotekanauki.pl/articles/47724.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Atlantic water
change
Mediterranean Sea
Egypt
natural activity
anthropogenic activity
temperature
salinity
trend
water mass
subsurface water
water column
Źródło:
Oceanologia; 2011, 53, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characteristic of polypropylene nanocomposite material reinforcement with hydroxyapatite for bone replacement
Autorzy:
Obaid, M. N.
Sabr, O. H.
Hussein, A. A.
Powiązania:
https://bibliotekanauki.pl/articles/1818801.pdf
Data publikacji:
2021
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
polypropylene
hydroxyapatite
osteoplastic cells
surface roughness
contact angle
wettability
bone replacement
clots creation
coagulates creation
polipropylen
hydroksyapatyt
chropowatość powierzchni
kąt zwilżania
zwilżalność
substytut kości
tworzenie
Opis:
Purpose: Human bone suffered some degeneration due to age and accidents; therefore, there are many interests in the prepared synthetic bone with properties nearer to natural bone. The present study prepared a nanocomposite of polypropylene reinforced with different weight fraction of Nano hydroxyapatite (HAp) to be used as a bone replacement with good biological properties that enhanced the growth of osteoplastic cells and enhance the prevention of clots and coagulates creation. Design/methodology/approach: Nanocomposite from polypropylene reinforced with different weight fraction of Hydroxyapatite (HAp) (1,2 and 3) % prepared by first dispersion Nano hydroxyapatite insolvent and then mixing with a pellet of polypropylene by the twin-screw extrusion process, the current research study the surface properties ( atomic force microscopy (AFM), contact angle test) Moreover, it studied the characteristics of prepared nanocomposite materials (Differential Scanning Calorimetry (DSC), Field Emission-Scanning Electron Microscopy (FE-SEM) and Fourier Transform Infrared (FTIR)). Findings: The AFM results show the surface roughness decreased with increasing content of HAp, which diminished the chance of creation clots and coagulates on it. The contact angle results referred to polypropylene behaviour transformed from hydrophobic to hydrophilic with addition HAp that permission to grow the osteoplastic cell on it, so the healing process is accelerated. Moreover, the FE-SEM images revealed uniform distribution and good bonding between polypropylene and Hydroxyapatite. The thermal properties were measured by the DSC test showed the melting temperature, and the enthalpy of melting (indicated to increase the crystalline structure per cent) are increased with increasing the percentage of Hydroxyapatite. Research limitations/implications: This research studied the characteristics of nanocomposite materials prepared by three steps (dispersion by ultrasonic device, manually mixed and melting and mixing by twin extruder) which can be used as a bone replacement. However, the main limitation was the uniform distribution of nano-hydroxyapatite within the matrix. In a further study, the cytotoxic test can be tested to study the effect of prepared nanocomposite on living cells’ growth. Practical implications: The interest object is how to connect among different properties to prepared bone replacement with good properties and biocompatibility that made able to stimulate the growth and healing process. Originality/value: The nano-hydroxyapatite is a biomaterial that has a composition similar to the natural mineral phase of the bone and does not have any negative effect, which enhanced the growth of osteoplastic cells and decreased the clots and coagulates creation; therefore, nano-hydroxyapatite is used to decrease the surface roughness which decreased the chance of coagulation creation and to enhance the hydrophilic properties.
Źródło:
Journal of Achievements in Materials and Manufacturing Engineering; 2021, 104, 1; 21--30
1734-8412
Pojawia się w:
Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The pulmonary involvement in Theileria lestoquardi naturally infected sheep
Autorzy:
El Imam, A.H.
Hassan, S.M.
Gameel, A.A.
El Hussein, A.M.
Taha, K.M.
Powiązania:
https://bibliotekanauki.pl/articles/6255.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Parazytologiczne
Opis:
Malignant Ovine Theileriosis (MOT) caused by Theileria lestoquardi is considered a major constraint for sheep production in many areas of the world including Sudan. Pulmonary oedema is thought to be the main cause of animal death, but the mechanism, the cell types involved and/or the probable cause of this pneumonia has yet to be defined. The present study was carried out to investigate the pulmonary involvement post T. lestoquardi infection and to identify the cell types involved in pneumonia. Apparently healthy sheep were exposed to ticks challenge in T. lestoquardi endemic area. Lungs impression smears and tissue sections for histopathology were processed. At necropsy, fifteen infected sheep revealed severe pneumonia associated with oedema and accumulation of creamygrayish frothy exudates. The microscopic findings of examined lungs showed emphysema, congestion, collapse and proliferation of immense amount of different kinds of cells. The current study indicates that T. lestoquardi infections are accompanied with remarkable pulmonary involvements and may lead to respiratory failure and death.
Źródło:
Annals of Parasitology; 2016, 62, 1
0043-5163
Pojawia się w:
Annals of Parasitology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Molecular identification of different Theileria and Babesia species infecting sheep in Sudan
Autorzy:
El Imam, A.E.
Hassan, S.M.
Gameel, A.A.
El Hussein, A.M.
Taha, K.M.
Oosthuizen, M.C.
Powiązania:
https://bibliotekanauki.pl/articles/5972.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Parazytologiczne
Opis:
The epidemiological aspects of sheep piroplasmosis in Sudan are poorly studied, and further investigations using sensitive and precise techniques are required. In this study, the Reverse Line Blot (RLB) hybridization assay was used to detect and simultaneously differentiate between Theileria and Babesia species. DNA was extracted from blood collected on filter paper (n=219) from apparently healthy sheep from six different geographical localities in Sudan. Results indicated that Theileria ovis (88.6%), T. separata (20.1%), T. lestoquardi (16.4%) and T. annulata (16.4%) DNA could be detected in the blood samples. Single and mixed Theileria infections were detected in 74 (33.8%) and 124 (56.6%) respectively and T. ovis being the most prevalent species in the country. T. ovis and T. separata were reported for the first time in sheep in Sudan.
Źródło:
Annals of Parasitology; 2016, 62, 1
0043-5163
Pojawia się w:
Annals of Parasitology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of QUAL2K Model for Simulating Water Quality in Hilla River, Iraq
Autorzy:
Al-Dalimy, Shahad Z.
Al-Zubaidi, Hussein A. M.
Powiązania:
https://bibliotekanauki.pl/articles/24202900.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
water quality
QUAL2K
management modeling
Hilla River
BOD
DO
Opis:
The quality of the water in Iraq’s Hilla River has been severely degraded as a result of human activities and industrial development. The QUAL2K model, a widely used one-dimensional water quality model, was used to simulate the river’s water quality parameter of CBODu and DO utilizing river and point-source flows rate as well as quality of water metrics observed along the river. Despite a severe lack of data in the research region, the QUAL2K model was determined to be an adequate instrument for the evaluation of quality of water. Simulated results of DO, BOD5, and temperature for the period (October 2022) showed the robustness of the model. Results showed that the two parameters (CBOD and DO) ranged between (9.5 and 10.65) mg/L and between (1.425 and 3.075) mg/L, respectively. Based on statistics, good agreement was found between the model predictions and field data. Thus, using QUAL2K model is an effective tool to manage the river water quality.
Źródło:
Journal of Ecological Engineering; 2023, 24, 6; 272--280
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
4D Reservoir Geomechanical Modelling Provides Safe Drilling Operations in North Kuwait Stacked Reservoirs
Geomechaniczne modelowanie złożowe typy 4-D umożliwia bezpieczne wiercenia w wielohoryzontowych złożach w północnym Kuwejcie
Autorzy:
Deib, S. M.
Mohamad-Hussein, A.
El-Din, H.
Khan, A.
Powiązania:
https://bibliotekanauki.pl/articles/1835422.pdf
Data publikacji:
2017
Wydawca:
Instytut Nafty i Gazu - Państwowy Instytut Badawczy
Tematy:
reservoir geomechanics
mud weight
wellbore stability
geochemika złożowa
gęstość płuczki
stabilność odwiertu
Opis:
The mature Raudhatain and Sabriya fields have been in production for the last six decades. Each field consists of four main reservoirs that are vertically stacked over a depth of 12.000 ft and separated by shales. The field development strategy is, to drill several horizontal wells within the individual reservoirs to maximize production. Some of these horizontal and highly deviated wells, experienced severe drilling problems, such as stuck pipe and side-tracking. As reservoir pressure changes during the life of the field, the stress state is modified. Such changes have an impact on well completions and the behaviour of faults. Therefore, the combined effect of well trajectory and in-situ stress changes on wellbore stability, should be thoroughly investigated. Not only is it important to understand the natural geomechanical behaviour of the reservoir during production, but it is also important to know, how to harness that behaviour to enhance productivity. At the same time, it is essential that the geomechanics of the field are understood to avoid costly mistakes. Therefore, a 4D geomechanical model that integrates geology, petrophysics, laboratory testing, fluid flow and geomechanics to obtain a representative equilibrated stress state prior to and during production was constructed. The results can be used to compute 3D critical drilling mud weights that provide guidelines for the placement of new wells and necessary drilling mud weights along planned wells.
Złoża Raudhatain i Sabriya są eksploatowane od sześciu dekad. Każde z nich składa się z czterech głównych horyzontów odizolowanych warstwami łupkowymi w zakresie głębokości 12 000 stóp. Strategia rozwiercania tych złóż maksymalizująca wydobycie obejmuje kilkanaście odwiertów poziomych i silnie krzywionych w obrębie poszczególnych horyzontów. Wiercenia niektórych z tych odwiertów napotykają trudności w postaci zakleszczenia przewodów wiertniczych i niekontrolowanych odchyleń. Na skutek zmian ciśnienia złożowego występują istotne zmiany w rozkładzie naprężeń skały złożowej. Zmiany te w istotny sposób wpływają na proces uzbrajania odwiertów oraz właściwości uskoków. W konsekwencji badania wymaga oddziaływanie trajektorii otworu i zmienionych naprężeń i jego wpływ na stabilność otworu. Dlatego istotnym staje się zrozumienie naturalnych procesów geomechanicznych zachodzących w złożu podczas procesu wydobycia jak również sposobów ich wykorzystania dla zwiększenia produktywności złoża. Jednocześnie pozwala ono uniknąć kosztownych błędów w procesie wiercenia i eksploatacji. W tym celu skonstruowano modele geomechaniczne typu 4D złóż obejmujące dane geologiczne, petrofizyczne, laboratoryjne oraz dotyczące przepływów i geomechaniki, które pozwoliły określić równowagowy rozkład naprężeń zarówno przed jak i w trakcie eksploatacji. Wyniki te mogą być wykorzystane dla określenia optymalnych parametrów wierceń takich jak lokalizacje i trajektorie otworów czy wymagane gęstości płuczki.
Źródło:
Nafta-Gaz; 2017, 73, 3; 157-161
0867-8871
Pojawia się w:
Nafta-Gaz
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A complexity efficient PAPR reduction scheme for FBMC-based VLC systems
Autorzy:
Roshdy, Radwa A.
Hussein, Aziza I.
Mabrook, Mohamed M.
Salem, Mohammed A.
Powiązania:
https://bibliotekanauki.pl/articles/2204164.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
visible light communication
filter bank multicarrier
peak-to-average power ratio reduction
computational complexity
cube satellite communication link
inter-satellite communications
Opis:
Visible light communication based on a filter bank multicarrier holds enormous promise for optical wireless communication systems, due to its high-speed and unlicensed spectrum. Moreover, visible light communication techniques greatly impact communication links for small satellites like cube satellites, and pico/nano satellites, in addition to inter-satellite communications between different satellite types in different orbits. However, the transmitted visible signal via the filter bank multicarrier has a high amount of peak-to-average power ratio, which results in severe distortion for a light emitting diode output. In this work, a scheme for enhancing the peak-to-average power ratio reduction amount is proposed. First, an algorithm based on generating two candidates signals with different peak-to- average power ratio is suggested. The signal with the lowest ratio is selected and transmitted. Second, an alternate direct current-biased approach, which is referred to as the addition reversed method, is put forth to transform transmitted signal bipolar values into actual unipolar ones. The performance is assessed through a cumulative distribution function of peak-to-average power ratio, bit error rate, power spectral density, and computational complexity. The simulation results show that, compared to other schemes in literature, the proposed scheme attains a great peak-to-average power ratio reduction and improves the bit the error rate performance with minimum complexity overhead. The proposed approach achieved about 5 dB reduction amount compared to companding technique, 5.5 dB compared to discrete cosine transform precoding, and 8 dB compared to conventional direct current bias of an optical filter bank multicarrier. Thus, the proposed scheme reduces the complexity overhead by 15.7% and 55.55% over discrete cosine transform and companding techniques, respectively.
Źródło:
Opto-Electronics Review; 2023, 31, 1; art. no. e144919
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of a molybdenum-reducing bacterium with the ability to degrade phenol, isolated in soils from Egypt
Autorzy:
Ibrahim, Y.
Abdel-Mongy, M.
Shukor, M.S.
Hussein, S.
Ling, A.P.K.
Shukor, M.Y.
Powiązania:
https://bibliotekanauki.pl/articles/80115.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
molybdenum
molybdenum-reducing bacteria
contaminated soil
bioremediation
nonylphenol
phenol
Egypt
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2015, 96, 3
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fusaria and other fungi taxa associated with rhizosphere and rhizoplane of lentil and sesame at different growth stages
Autorzy:
Abdel-Hafez, S.I.I.
Ismail, M.A.
Hussein, N.A.
Abdel-Hameed, N.A.
Powiązania:
https://bibliotekanauki.pl/articles/67219.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
Fusarium
fungi
rhizosphere
rhizoplane
lentil
sesame
growth stage
Lens culinaris
Sesamum indicum
Opis:
Density and diversity of Fusarium species and other fungi associated with rhizosphere and rhizoplane of lentil and sesame plants at three different growth stages were investigated. Sixteen species of Fusarium were isolated from rhizosphere (13 species) and rhizoplane (11) of both plants studied. In lentil, 11 species were recorded from its rhizosphere (9 species) and rhizoplane (8). Fusarium species associated with lentil rhizoplane gave highest number of propagules at the first stage of plant growth while the ones of Fusarium associated with the rhizosphere produced the highest number at the second stage of growth. F. solani was the most common in the three growth stages. In addition, of two growth stages, F. culmorum and F. tricinctum were isolated from the rhizosphere while F. nygamai and F. verticillioides from the rhizoplane. The other species were recorded from only one growth stage of lentil plant. In sesame plants, rhizosphere yielded nine Fusarium species while rhizoplane gave only six from the three stages investigated. Stage I of sesame rhizosphere possessed the highest colony forming units of Fusarium. As the case for lentil, F. solani was the most common species in sesame rhizospere and rhizoplane. F. verticillioides and F. nygamai (in three different growth stages) followed by F. oxysporum and F. tricinctum (in two growth stages) were recorded using the dilution-plate and/or soil-plate methods from sesame rhizosphere soils. Rhizoplane Fusarium species of sesame plants were isolated at the three different growth stages with almost equal number of colony forming units. F. poae came after F. solani in its frequency since it was recovered from two growth stages. Several of the isolated species are well-known as pathogens to many cultivated plants. To the best of our knowledge, three species are recorded here for the first time in Egypt from the rhizosphere (F. acutatum), rhizoplane of sesame plants (F. longipes) and from rhizosphere of both lentil and sesame and rhizoplane of lentil (F. nygamai).
Źródło:
Acta Mycologica; 2012, 47, 1
0001-625X
2353-074X
Pojawia się w:
Acta Mycologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Complex Signal Mapping for Improving Spectral Efficiency of Li-Fi Systems
Autorzy:
Sileh, Ibrahim K.
Abdulkafi, Ayad A.
Hussein, Mohammed K.
Hardan, Saad M.
Powiązania:
https://bibliotekanauki.pl/articles/958061.pdf
Data publikacji:
2019
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
Li-Fi
OFDM
signal mapping
PAPR
BER
Opis:
Light fidelity (Li-Fi) systems based on the orthogonal frequency division multiplexing (OFDM) scheme have gained more attention in the communications circles, as a means to provide high spectral efficiency and ensure stricter data rate requirements for visible light communication (VLC) systems. However, common OFDM schemes employ Hermitian symmetry to obtain a real-valued signal which is necessary in intensity modulation and direct detection (IM/DD) optical systems, at the expense of doubling the required bandwidth. In this paper, a novel transmission scheme for an OFDM-based Li-Fi system is proposed to tackle the issue in question. A new approach to complex signal mapping (CSM), based on the pairing function method, has been developed for Li-Fi systems. It does not require Hermitian symmetry and, hence, saves about 50% of the required bandwidth. Unlike existing OFDM-based VLC approaches, the proposed scheme employs CSM to ensure a real and positive signal without Hermitian symmetry in order to fully utilize the bandwidth available to Li-Fi networks. Simulation results show that the proposed scheme significantly outperforms other systems in terms of spectral efficiency. The CSM-OFDM based Li-Fi system also achieves a good peak-to-average power ratio (PAPR) reduction with acceptable bit-error-rate (BER) performance, compared to conventional approaches.
Źródło:
Journal of Telecommunications and Information Technology; 2019, 3; 58-62
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trend Detection in Climate Change Indicators Using Non-Parametric Statistics: A Case Study of Abu Dhabi, United Arab Emirates
Autorzy:
Basarir, A.
Arman, H.
Hussein, S.
Murad, A.
Aldahan, A.
Abdulla Al-Abri, M.
Powiązania:
https://bibliotekanauki.pl/articles/1031779.pdf
Data publikacji:
2017-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
92.70.Kb
92.05.Df
Opis:
This study focuses on detecting trends for climate change indicators, such as average monthly temperature, rainfall, humidity, and wind speed for fourteen stations located between Al Ain and Abu Dhabi cities of the United Arab Emirates. Mann-Kendall non-parametric test was run on monthly time series data for the period 2003-2015 with consideration of seasonality. Significant increasing/decreasing trends in rainfall (for four stations), humidity (for six stations), and wind speed (for nine stations) were detected while no significant trend was observed in temperature for all stations.
Źródło:
Acta Physica Polonica A; 2017, 132, 3; 655-657
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sex-related differences in physical therapy career expectations in Ha’il, Saudi Arabia
Autorzy:
Hussein, Hisham M.
Alshammari, Salma F.
Alanazi, Ibtisam A.
Alenzy, Gharam M.
Alrashidy, Renad H.
Powiązania:
https://bibliotekanauki.pl/articles/29519452.pdf
Data publikacji:
2022-11-18
Wydawca:
Fundacja Edukacji Medycznej, Promocji Zdrowia, Sztuki i Kultury Ars Medica
Tematy:
Gender equality
females
physical therapy
career expectation
Opis:
Social and cultural factors can lead to gender-biased expectations in physical therapy (PT) career. In Saudi Arabia, female physical therapists might be undergoing more cultural competencies than males to develop their career. This study aimed to investigate whether there are differences between men and women physical therapists (PTs) in their career expectations in Saudi Arabia. We tested 496 responses 192 (38.7%) were males and 307 (61.3%) were females. 325 (65.5%) responses were obtained from students including those in the internship year while the rest of the responses 171 (34.5%) were from graduated PTs. A descriptive cross-sectional study was undertaken using a questionnaire sent electronically to PT students and graduates in Ha’il City, Saudi Arabia. The answers to questions regarding the future career expectation and the perception of PT career among other healthcare professions were analyzed. Statistically higher female numbers were expected to conduct research activity, become faculty teaching staff, continue their education, and attend special courses. No sex-related differences were found regarding the expectation to occupy a governmental job, own a private business and participate as an active member of the Saudi Physical Therapy Association. A higher proportion of females see that PT practice is as independent and prestigious as other medical and health specialties. Both genders considered PT is an prestigious as other heakth professions. There are sex-related differences in PT career expectations and the perception of PT career compared to other healthcare professions.
Źródło:
Acta Neuropsychologica; 2022, 20(4); 385-392
1730-7503
2084-4298
Pojawia się w:
Acta Neuropsychologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A proposed preamble channel estimation scheme for flip FBMC-based indoor VLC systems
Autorzy:
El-Ganiny, Mohamed Y.
Khalaf, Ashraf A. M.
Hussein, Aziza I.
Hamed, Hesham F. A.
Powiązania:
https://bibliotekanauki.pl/articles/2063904.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
channel estimation
filter bank multicarrier
IEEE 802.15.7 standard
interference approximation method
visible light communication
Opis:
Filter bank multicarrier waveform is investigated as a potential waveform for visible light communication broadcasting systems. Imaginary inter-carrier and/or inter-symbol interference are causing substantial performance degradation in the filter bank multicarrier system. Direct current-biased optical filter bank multicarrier modulation overcomes all the problems of direct current-biased optical-orthogonal frequency division multiplexing modulation approaches in terms of speed and bandwidth. However, it also wastes a lot of energy while transforming a true bipolar signal into a positive unipolar signal by adding direct current-bias. In this paper, a flip-filter bank multicarrier-based visible light communication system was introduced to overcome this problem. In this system, a bipolar signal is converted to a unipolar signal by isolating the positive and negative parts, turning them to positive and then delivering the signal. Also, a new channel estimation scheme for a flip-filter bank multicarrier system is proposed which improves the channel estimation performance compared to that of each of the conventional schemes. The proposed system performance is measured in terms of bit error rate, normalized mean squared error, and constellation diagram. The superiority of the proposed scheme over other conventional structures has been successfully verified by MATLAB 2020b simulation experiments results. These results are evaluated under indoor visible light communication standard.
Źródło:
Opto-Electronics Review; 2022, 30, 1; art. no. e140859
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cancelable template generation based on quantization concepts
Autorzy:
Nassar, Rana M.
Khalaf, Ashraf A. M.
El-Banby, Ghada M.
El-Samie, Fathi E. Abd
Hussein, Aziza I.
El-Shafai, Walid
Powiązania:
https://bibliotekanauki.pl/articles/27315703.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
cancelable biometrics
quantization concepts
DCT
JPEG
access control
authentication
Opis:
The idea of cancelable biometrics is widely used nowadays for user authentication. It is based on encrypted or intentionally-distorted templates. These templates can be used for user verification, while keeping the original user biometrics safe. Multiple biometric traits can be used to enhance the security level. These traits can be merged together for cancelable template generation. In this paper, a new system for cancelable template generation is presented depending on discrete cosine transform (DCT) merging and joint photographic experts group (JPEG) compression concepts. The DCT has an energy compaction property. The low-frequency quartile in the DCT domain maintains most of the image energy. Hence, the first quartile from each of the four biometrics for the same user is kept and other quartiles are removed. All kept coefficients from the four biometric images are concatenated to formulate a single template. The JPEG compression of this single template with a high compression ratio induces some intended distortion in the template. Hence, it can be used as a cancelable template for the user acquired from his four biometric traits. It can be changed according to the arrangement of biometric quartiles and the compression ratio used. The proposed system has been tested through merging of face, palmprint, iris, and fingerprint images. It achieves a high user verification accuracy of up to 100%. It is also robust in the presence of noise.
Źródło:
Opto-Electronics Review; 2023, 31, 3; art. no. e145940
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hybrid PAPR reduction schemes for different OFDM-based VLC systems
Autorzy:
El-Ganiny, Mohamed Y.
Khalaf, Ashraf A. M.
Hussein, Aziza I.
Hamed, Hesham F. A.
Powiązania:
https://bibliotekanauki.pl/articles/2174839.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
visible light communication
peak-to-average power ratio
bit error rate
Opis:
Orthogonal frequency division multiplexing has been widely used in many radio frequency wireless communication standards as a preferable multicarrier modulation scheme. The modulated signals of a conventional orthogonal frequency division multiplexing system are complex and bipolar. In intensity-modulated direct detection optical wireless communications, transmitted signals should be real and unipolar due to non-coherent emissions of an optical light emitting diode. In this paper, different hybrid optical systems have been proposed to satisfy real and unipolar signals. Peak-to-average power ratio is one of the biggest challenges for orthogonal frequency division multiplexing-based visible light communications. They are based on a combination of non-linear companding techniques with spreading or precoding techniques. Simulation evaluation is performed under direct current-biased optical orthogonal frequency division multiplexing, asymmetrically clipped optical orthogonal frequency division multiplexing, and Flip-orthogonal frequency division multiplexing systems in terms of peak-to-average power ratio, bit error rate, and spectral efficiency. The proposed schemes are investigated to determine a scheme with a low peak-to-average power ratio and an acceptable bit error rate. MATLABTM software has been successfully used to show the validity of the proposed schemes.
Źródło:
Opto-Electronics Review; 2022, 30, 3; art. no. e141951
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hybrid PAPR reduction schemes for different OFDM-based VLC systems
Autorzy:
El-Ganiny, Mohamed Y.
Khalaf, Ashraf A. M.
Hussein, Aziza I.
Hamed, Hesham F. A.
Powiązania:
https://bibliotekanauki.pl/articles/2174840.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
visible light communication
peak-to-average power ratio
bit error rate
Opis:
Orthogonal frequency division multiplexing has been widely used in many radio frequency wireless communication standards as a preferable multicarrier modulation scheme. The modulated signals of a conventional orthogonal frequency division multiplexing system are complex and bipolar. In intensity-modulated direct detection optical wireless communications, transmitted signals should be real and unipolar due to non-coherent emissions of an optical light emitting diode. In this paper, different hybrid optical systems have been proposed to satisfy real and unipolar signals. Peak-to-average power ratio is one of the biggest challenges for orthogonal frequency division multiplexing-based visible light communications. They are based on a combination of non-linear companding techniques with spreading or precoding techniques. Simulation evaluation is performed under direct current-biased optical orthogonal frequency division multiplexing, asymmetrically clipped optical orthogonal frequency division multiplexing, and Flip-orthogonal frequency division multiplexing systems in terms of peak-to-average power ratio, bit error rate, and spectral efficiency. The proposed schemes are investigated to determine a scheme with a low peak-to-average power ratio and an acceptable bit error rate. MATLABTM software has been successfully used to show the validity of the proposed schemes.
Źródło:
Opto-Electronics Review; 2022, 30, 3; art. no. e141951
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simultaneous Adsorption of Ternary Antibiotics (Levofloxacin, Meropenem, and Tetracycline) by SunFlower Husk Coated with Copper Oxide Nanoparticles
Autorzy:
Ibrahim, Mohammed A.
Shaban, Mohammed Ali A.
Hasan, Yaseen Rashid
M-Ridha, Mohanad J.
Hussein, Haitham A.
Abed, Khalid M.
Mohammed, Sabah J.
Muhamad, Mohd Hafizuddin
Hasan, Hassimi Abu
Powiązania:
https://bibliotekanauki.pl/articles/2105287.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
adsorption
antibiotics
neural network
wastewater
sustainable process
Opis:
In this study, a new adsorbent derived from sunflower husk powder and coated in CuO nanoparticles (CSFH) was investigated to evaluate the simultaneous adsorption of Levofloxacin (LEV), Meropenem (MER), and Tetracycline (TEC) from an aqueous solution. Significant improvements in the adsorption capacity of the sunflower husk were identified after the powder particles had been coated in CuO nanoparticles. Kinetic data were correlated using a pseudo-second-order model, and was successful for the three antibiotics. Moreover, high compatibility was identified between the LEV, MER, and TEC, isotherm data, and the Langmuir model, which produced a better fit to suit the isotherm curves. In addition, the spontaneous and exothermic nature of the adsorption process was crucial for transforming the three antibiotics into CSFH. The greatest CSFH adsorption capacity was in MER (131.83 mg/g), followed by TEC (96.95 mg/g), and LEV (62.24 mg/g). These findings thus indicate that CSFH is one of the most effective and efficient adsorbents to use for eliminating wastewater contaminated with antibiotic residue.
Źródło:
Journal of Ecological Engineering; 2022, 23, 6; 30--42
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
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