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Wyszukujesz frazę "El-Sayed, A.M.A" wg kryterium: Autor


Wyświetlanie 1-14 z 14
Tytuł:
A coupled system of fractional order integral equations in reflexive Banach spaces
Autorzy:
El-Sayed, A.M.A.
Hashem, H.H.G.
Powiązania:
https://bibliotekanauki.pl/articles/963436.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Weak solution
Pettis-integral of fractional order integration
Coupled system
Opis:
We present an existence theorem for at least one weak solution for a coupled system of integral equations of fractional order in reflexive Banach spaces relative to the weak topology.
Źródło:
Commentationes Mathematicae; 2012, 52, 1
0373-8299
Pojawia się w:
Commentationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Integrable solutions for quadratic Hammerstein and quadratic Urysohn functional integral equations
Autorzy:
El-Sayed, A.M.A
Hashem, H.H.G
Powiązania:
https://bibliotekanauki.pl/articles/745817.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Quadratic Hammerstein and Urysohn functional integral equations
Positive monotonic solutions
Measure of noncompactness
Opis:
The existence of positive monotonic solutions, in the class of continuous functions, for some nonlinear quadratic integral equation have been studied in [3], [6], [7] and [9]. Here We are concerning with the existence of \(L _1\) positive monotonic solutions for the quadratic Hammerstein and quadratic Urysohn functional integral equations.
Źródło:
Commentationes Mathematicae; 2008, 48, 2
0373-8299
Pojawia się w:
Commentationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On a mixed-type integral equation and fractional-order functional differential equations
Autorzy:
El-Sayed, A. M. A.
Sherif, Nagwa
Ibrahim, I. A.
Powiązania:
https://bibliotekanauki.pl/articles/745693.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Nonlinear functional integral equation
fractional calculus
Volterra operator
mixed type integral equation
Schauder fixed point theorem
Opis:
In this paper we study the existence of solution of a nonlinear integral equation of (mixed type) Volterra-Fredholm type. As an application we prove the existence of solution of an initial value problem of fractional order in the space of Lebesgue integrable functions on the interval \([0, 1]\).
Źródło:
Commentationes Mathematicae; 2005, 45, 2
0373-8299
Pojawia się w:
Commentationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Weak solutions of fractional order differential equations via Volterra-Stieltjes integral operator
Autorzy:
El-Sayed, A. M. A.
El-Sayed, W. G.
Abd El-Mowla, A. A. H.
Powiązania:
https://bibliotekanauki.pl/articles/357800.pdf
Data publikacji:
2017
Wydawca:
Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:
weak solution
mild solution
weakly Riemann-Stieltjes integral
function of bounded variation
Banach space
rozwiązanie całkowe
całka Riemanna-Stieltjesa
funkcja o ograniczonej zmienności
przestrzeń Banacha
Opis:
The fractional derivative of the Riemann-Liouville and Caputo types played an important role in the development of the theory of fractional derivatives, integrals and for its applications in pure mathematics ([18], [21]). In this paper, we study the existence of weak solutions for fractional differential equations of Riemann-Liouville and Caputo types. We depend on converting of the mentioned equations to the form of functional integral equations of Volterra-Stieltjes type in reflexive Banach spaces.
Źródło:
Journal of Mathematics and Applications; 2017, 40; 85-96
1733-6775
2300-9926
Pojawia się w:
Journal of Mathematics and Applications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of chelated iron and silicon on the yield and quality of tomato plants grown under semi-arid conditions
Autorzy:
El-Salam Shalaby, O.A.
Konopinski, M.
El-Sayed Ramadan, M.
Powiązania:
https://bibliotekanauki.pl/articles/11543589.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Przyrodniczy w Lublinie. Wydawnictwo Uniwersytetu Przyrodniczego w Lublinie
Opis:
The influence of chelated iron (0, 250 and 500 mg·L–1 as Fe-EDDHA 6%) and silicon (0, 2, 4 mmol·L–1 as K2SiO3) on the yield and quality of tomato (Solanum lycopersicum L.), Strain B cultivar, were investigated under semi-arid conditions in Ras Sudr region, Egypt, in years 2013–2014. A significant influence of chelated iron and silicon applications on tomato growth, yield and quality were observed. The highest plant growth, leaf mineral contents (N, P and K), vitamin C and Ca contents in fruit, fruit firmness, early and total yield were observed in plants which treated with 500 mg·L–1 chelated iron and 2 and 4 mmol·L–1 silicon. Meanwhile, these treatments decreased the proline content of leaves and T.S.S content of fruit.
Źródło:
Acta Scientiarum Polonorum. Hortorum Cultus; 2017, 16, 6; 29-40
1644-0692
Pojawia się w:
Acta Scientiarum Polonorum. Hortorum Cultus
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the Existence of Continuous Positive Monotonic Solutions of a Self-Reference Quadratic Integral Equation
Autorzy:
EL-Sayed, Ahmed M.A.
Ebead, Hanaa R.
Powiązania:
https://bibliotekanauki.pl/articles/1818643.pdf
Data publikacji:
2020
Wydawca:
Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:
self-reference
quadratic integral equation
existence of solutions
uniqueness of solution
continuous dependence
Schauder fixed point theorem
równanie całkowe
rozwiązania
zależność ciągła
punkt stały Schaudera
Opis:
In this work we study the existence of positive monotonic solutions of a self-reference quadratic integral equation in the class of continuous real valued functions. The continuous dependence of the uniquesolution will be proved. Some examples will be given.
Źródło:
Journal of Mathematics and Applications; 2020, 43; 67--80
1733-6775
2300-9926
Pojawia się w:
Journal of Mathematics and Applications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Immunological and genotoxic effects of occupational exposure to α-cypermethrin pesticide
Autorzy:
El Okda, El-Sayed
Abdel-Hamid, Mona A.
Hamdy, Ahmed M.
Powiązania:
https://bibliotekanauki.pl/articles/2161902.pdf
Data publikacji:
2017-06-19
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
p53
pyrethroids
immunological
genotoxic
cypermethrin
Oxidative stress
Opis:
Objectives The aim of this work has been to find out the occupational oxidative stress, immunological and genotoxic health hazards among α-cypermethrin (CYP) pesticide-exposed workers. Material and Methods A cross-sectional study was performed including 200 workers divided into 3 groups according to the level of exposure: highly exposed group (50 workers), moderately exposed group (50 workers) and unexposed group (100 workers). All workers were subjected to detailed laboratory investigation for gene P53 mutations, immunological parameters as a cluster of differentiation into 3 percentage (CD3%), CD4% and CD8% in addition to peripheral blood total leukocytic and platelet counts that were measured. Spectrophotometer technique was used for detection of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and glutathione peroxidase (GPx). Air samples were collected with a High Volume Small Surface Sampler for measurement of α-cypermethrin level. Results A highly exposed group to the α-cypermethrin had lower CD4/CD8 as compared to an unexposed group with statistically significant difference. As regards gene mutation, exons 5a and 6 were more frequent among the highly exposed group as compared to no mutation among moderately exposed and unexposed groups with significant difference. As regards antioxidants; SOD, CAT, GSH and GPx were higher among the unexposed group as compared to the highly and moderately exposed group with statistically significant difference. Significant negative correlation was found between working years and antioxidant parameters. Conclusions Repeated exposure to α-CYP may lead to gene mutations, immunological disturbances and oxidative stress. Strict safety precautions are required not only for workers but also for public users. Int J Occup Med Environ Health 2017;30(4):603–615
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2017, 30, 4; 603-615
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dimming control schemes combining IEEE 802.15.7 and SC-LPPM modulation schemes with an adaptive M-QAM OFDM for indoor LOS VLC systems
Autorzy:
Mohammed, Nazmi A.
Badawi, Kareem A.
Khalaf, Ashraf A. M.
El-Rabaie, El-Sayed
Powiązania:
https://bibliotekanauki.pl/articles/1818230.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
visible light communication
sub-carrier pulse position modulation
lightning topologies
bit error rate
Opis:
The presented work proposes a new dimming control schemes for indoor visible light communication which combines variable pulse-position modulation, colour shift keying as key schemes of IEEE 802.15.7 standard, and sub carrier-pulse-position modulation as a pulse-position modulation variant with orthogonal frequency division multiplexing. These schemes are then compared with traditional merging schemes utilizing pulse-width modulation and multiple pulse-position modulation with m-ary quadrature amplitude modulation OFDM. The proposed schemes are investigated in a typical room with a different lighting layout (i.e., distinctive and uniform lighting layout), followed by an illumination investigation to evaluate the performance of the proposed schemes, especially the enhanced achieved data rates, and to determine their limitations as reliable visible light communication systems that can satisfy both communication and illumination requirements.
Źródło:
Opto-Electronics Review; 2020, 28, 4; 203--212
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of genetic algorithm for optimization the safety system of the nuclear reactor
Autorzy:
El-Sayed Wahed, M.
Ibrahim, W. Z.
Effat, A. M.
Powiązania:
https://bibliotekanauki.pl/articles/146492.pdf
Data publikacji:
2009
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
genetic algorithm
non-dominated sorting
chimney water injection system (CWIS)
Egypt nuclear
Opis:
The purpose of this paper is to present an approach to optimization in which every target is considered as a separate objective to be optimized. Multi-objective optimization is a powerful tool for resolving conflicting objectives in engineering design and numerous other fields. One approach to solve multi-objective optimization problems is the non-dominated sorting genetic algorithm (NSGA). Genetic algorithm (GA) was applied in regarding the choice of the time intervals for the periodic testing of the components of the chimney water injection system (CWIS) of the 22 MW open pool multipurpose reactor (MPR), ETRR-2, at the Egyptian Atomic Energy Authority, has been used as a case study.
Źródło:
Nukleonika; 2009, 54, 1; 51-56
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Genetic algorithms and neural networks for solving water quality model of the Egyptian research reactor
Autorzy:
El-Sayed Wahed, M.
Ibrahim, W. Z.
Effat, A. M.
Powiązania:
https://bibliotekanauki.pl/articles/148150.pdf
Data publikacji:
2009
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
genetic algorithm
neural networks
model calibration
water distribution system
water quality model
Opis:
The second Egyptian research reactor ETRR-2 became critical on 27th November, 1997. The National Center of Nuclear Safety and Radiation Control (NCNSRC) has the responsibility for the evaluation and assessment of safety of this reactor. Modern managements of water distribution system (WDS) need water quality models that are able to accurately predict the dynamics of water quality variations within the distribution system environment. Before water quality models can be applied to solve system problems, they should be calibrated. The purpose of this paper is to present an approach which combines both macro and detailed models to optimize the water quality parameters. For an efficient search through the solution space, we use a multi-objective genetic algorithm which allows us to identify a set of Pareto optimal solutions providing the decision maker with a complete spectrum of optimal solutions with respect to the various targets. This new combinative algorithm uses the radial basis function (RBF) metamodeling as a surrogate to be optimized for the purpose of decreasing the times of time-consuming water quality simulation and can realize rapidly the calibration of pipe wall reaction coefficients of chlorine model of large-scaled WDS.
Źródło:
Nukleonika; 2009, 54, 4; 239-245
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phenolic compounds and antioxidant activity of rice straw extract
Autorzy:
Elzaawely, A.A.
Maswada, H.F.
El-Sayed, M.E.A.
Ahmed, M.E.
Powiązania:
https://bibliotekanauki.pl/articles/10781.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Źródło:
International Letters of Natural Sciences; 2017, 64
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mineralogical study and enhanced gravity separation of gold-bearing mineral, South Eastern Desert, Egypt
Autorzy:
El-Sayed, Samah
Abdel-Khalek, N. A.
El-Shatoury, E. H.
Abdel-Motelib, A.
Hassan, M. S.
Abdel-Khalek, M.A.
Powiązania:
https://bibliotekanauki.pl/articles/1845207.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
gold
mineralogy
petrography
gravity separation
Falcon concentrator
Opis:
El-Hudi gold deposit, located in the South Eastern Desert of Egypt, represent large vein- type gold occurrence. The representative sample revealed the abundance of quartz as main constituent with minor amounts of mineral impurities. Gold was detectable (12 g/t) as determined using atomic absorption. The petrographic study revealed that the gold grains ranged from 10-40 μm. The grain boundaries of quartz are highly stained with iron minerals as hematite and limonite. Sericite mineral is common in discrete gold-bearing veins. Eroded pyrite was detected with high alteration leaving only cubic-shaped cavities behind. Different techniques for gravity separation were used to separate gold from the quartz mineral. After crushing and grinding of the sample, shaking table was used to upgrade the coarser fractions while Falcon concentrator was employed to upgrade the fine fraction. The best concentrate was obtained through grinding the whole sample to less than 0.2 mm, followed by cleaning steps. The gold content is increased from 12 to 145 g/t with total recovery of 78%.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 5; 839-848
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimizing the removal of iron oxide from Egyptian feldspar ore
Autorzy:
Yassin, E. Khaled
Elbendari, A.M.
Hassan, El-Sayed R. E.
Powiązania:
https://bibliotekanauki.pl/articles/27323643.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
feldspar ore
iron oxide contamination
ball mill
Carpco magnetic separator
acid leaching
whiteness
Opis:
The demand for feldspar as a raw material for various industrial applications continuously increases. Feldspar is a primary raw material in manufacturing ceramics, glass, fillers, welding electrodes, and enamel. Feldspar is often associated with iron oxide, which decreases its economic value and hinders its industrial application. The present work aimed at reducing iron oxide content in Egyptian feldspar ore from the Wadi Zerabi locality. Ball milling was used for preparing feldspar feed of size -250+45μm. Carpco dry high-intensity magnetic separation followed by acid leaching processes were carried out in order to decrease the iron contamination and increase the feldspar content. A Box-Behnken statistical design was used to optimize the magnetic separation results. From a feldspar feed containing 1.40% Fe2O3, a non-magnetic concentrate of 0.25% Fe2O3 was obtained. The Fe2O3 removal reached up to 82% with a high yield as the % weight of non-magnetic feldspar reached up to 97.5%. The leaching process further reduced the iron oxide content down to 0.19 %. Also, the feldspar whiteness was improved from 65.17% in the original ore to 85.60% in the leached product.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 6; art. no. 176420
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of polymers on the grinding and rheology of ultrafine Egyptian calcium carbonate suspension
Autorzy:
Mourad, Sabreen H
Khalil, Mostafa M. H.
Abdel-Khalek, N. A.
Abdel-Khalek, M. A.
Selim, K. A.
Hassan, El-Sayed R. E.
Powiązania:
https://bibliotekanauki.pl/articles/2175428.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fillers
calcium carbonate
ultra-fine grinding
surface modifications
Mechano-chemical
activation
polymers
Opis:
The investigation of surface modification of Egyptian calcium carbonate via polymers was achieved with simultaneous ultra-fine grinding. Attrition mill and planetary mill were used for wet and dry grinding, respectively. The parameters affecting the grinding were studied such as ball number, speed and grinding time. The rheological characteristics of the aqueous calcium carbonate suspensions were studied in the presence of different types of polymers. The results indicated that the mechanical force could clearly affect the modification characteristics of calcium carbonate due to its mechanochemical effects. The viscosity of calcium carbonate suspension depends on the volume percentage or weight percentage. The dispersing agent increases the solid concentration for a given particle fineness.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 6; art. no. 152163
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-14 z 14

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