Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Rana, M." wg kryterium: Autor


Wyświetlanie 1-6 z 6
Tytuł:
Some exact solutions for Oldroyd-B fluid due to time dependent prescribed shear stress
Wybrane rozwiązania dokładne dla cieczy Oldroyda-B przy zadanej funkcji naprężeń stycznych zależnej od czasu
Autorzy:
Jamil, M.
Fetecau, C.
Rana, M.
Powiązania:
https://bibliotekanauki.pl/articles/280504.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
Oldroyd-B fluid
velocity field
time-dependent shear stress
Hankel transform
Opis:
The velocity field and the shear stress corresponding to motion of an Oldroyd-B fluid between two infinite coaxial circular cylinders are established by means of the Hankel transforms. The flow of the fluid is produced due to the time dependent axial shear stress applied on the boundary of the inner cylinder. The exact solutions, presented under a series form, can easily be specialized to give similar solutions for the Maxwell, second grade and Newtonian fluids performing the same motion. Finally, some characteristics of the motion as well as the influence of the material constants on the behavior of the fluid are underlined by graphical illustrations.
Pole prędkości i pole rozkładu naprężeń stycznych wywołanych ruchem cieczy Oldroyda-B umieszczonej między dwoma koncentrycznymi cylindrami wyznaczono za pomocą transformaty Hankela. Przepływ cieczy wywołano zależnym od czasu naprężeniem stycznym od zewnętrznej ściany cylindra wewnętrznego. Uzyskane rozwiązanie dokładne, ujęte w formie rozwinięcia w szereg, może łatwo być zastosowane dla przypadków szczególnych cieczy Maxwella, cieczy drugiego stopnia i nienewtonowskich przy tych samych warunkach przepływu. Na zakończenie rozważań, przedstawiono graficznie charakterystyki ruchu cieczy i wpływ parametrów materiałowych na jej zachowanie.
Źródło:
Journal of Theoretical and Applied Mechanics; 2012, 50, 2; 549-562
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
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:
Effect of Reactor Pressure on Electrical and Structural Properties of Diamond Films Grown by Hot-Filament CVD
Autorzy:
Ullah, M.
Ahmed, E.
Rana, A.
Powiązania:
https://bibliotekanauki.pl/articles/1030224.pdf
Data publikacji:
2017-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
HFCVD
electrical properties
diamond films
growth
reactor pressure
Opis:
Polycrystalline diamond films with preferred (111) and (222) facets were fabricated inside hot filament chemical vapour deposition reactor on silicon wafers using a mixture of 1% methane in hydrogen at various reactor pressures ranging from 10 to 50 mbar. Regarding characterization of diamond films, internal texture, surface morphology, quality of diamond and electrical conductivity were investigated using X-ray diffraction, scanning electron microscopy, the Raman spectroscopy and four-point-probe van der Pauw techniques, respectively. Results of these studies demonstrate that polycrystalline diamond structure is grown in random orientation with (111) facet being dominant showing sharp grain boundaries. Moreover, growth rate was found to increase with pressure up to 20 mbar and then decreased for further rise in pressure. That is why grain density is high with relatively smaller grains at higher pressures caused by higher nucleation rates. In contrast, electrical resistivity decreased ≈3 orders of magnitude showing a minimum at 2.9×10⁶ Ω cm as pressure was increased in the reactor. Reactor pressure during film growth resulted in poor surface morphology, absence of sp³ bonds and low resistivity. Hence, decrease of resistivity makes diamond films desirable for many electrical applications in semiconducting/electronic devices.
Źródło:
Acta Physica Polonica A; 2017, 131, 6; 1419-1425
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Resource scheduling in cloud environmet: a survey
Autorzy:
Mangla, N.
Singh, M.
Rana, S. K.
Powiązania:
https://bibliotekanauki.pl/articles/102866.pdf
Data publikacji:
2016
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
resource scheduling
energy conservation
cloud computing
virtualization
service level agreement
Opis:
Cloud Computing offers the avant-garde services at a stretch that are too attractive for any cloud user to ignore. With its growing application and popularization, IT companies are rapidly deploying distributed data centers globally, posing numerous challenges in terms of scheduling of resources under different administrative domains. This perspective brings out certain vital factors for efficient scheduling of resources providing a wide genre of characteristics, diversity in context of level of service agreements and that too with user-contingent elasticity. In this paper, a comprehensive survey of research related to various aspects of cloud resource scheduling is provided. A comparative analysis of various resource scheduling techniques focusing on key performance parameters like Energy efficiency, Virtual Machine allocation and migration, Cost-effectiveness and Service-Level Agreement is also presented.
Źródło:
Advances in Science and Technology. Research Journal; 2016, 10, 30; 38-50
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fabrication and Characterization of Al6061-Nano Al2O3 Composites by Ultrasonic Assisted Stir Casting followed by Heat Treatment and Hot Forging
Autorzy:
Purohit, Rajesh
Qureshi, M.M.U.
Kumar, Ashish
Mishra, Abhishek
Rana, R.S.
Powiązania:
https://bibliotekanauki.pl/articles/28099519.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Al6061 alloy
Al6061-Al2O3 nanocomposites
XRD analysis
FESEM
mechanical properties
automotive gears
Opis:
The present work comprises the development of Al6061/nano Al2O3 composites with 0 to 4 weight percent in steps of 0.5 wt. % of nano alumina particles by using ultrasonic assisted stir casting. Casted samples were subjected to heat treatment and hot forging. Further forged and heat-treated gear blanks of nano Al2O3 (0 to 3.0 weight %) reinforced nanocomposites were machined to make spur gears for the wear test. The results have shown that nano Al2O3 reinforcement in the Al6061 matrix with heat treatment and forging improves the hardness and compressive strength up to 3.5 wt. %, after that, it starts decreasing because of the agglomeration of nano alumina particles. SEM results reveal grain refinement of the pure alloy after reinforcement. Removal of porosity and voids observed after forging operation. Wear resistance increasing with incorporation of Al2O3 nanoparticles in base alloy, reinforcement wt. %, precipitation hardening and hot forging also improves wear resistance and mechanical properties. These composites have widespread applications in gear, brake discs, crankshaft, clutch plates, pistons, and other components of automobiles and aircraft structures.
Źródło:
Archives of Metallurgy and Materials; 2023, 68, 2; 791--798
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of Triangular Core Rotation of a Hybrid Porous Core Terahertz Waveguide
Autorzy:
Ali, S.
Ahmed, N.
Alwee, S.
Islam, M.
Rana, S.
Bhuiyan, T.
Powiązania:
https://bibliotekanauki.pl/articles/227154.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
porous core waveguide
THz waveguide
flat EML
hybrid design
flat dispersion
triangular design
core rotation
Opis:
In this paper, we investigate the effects for rotating the triangular core air hole arrangements of a hybrid design porous core fiber. The triangular core has been rotated in anticlockwise direction to evaluate the impact on different waveguide properties. Effective Material Loss (EML), confinement loss, bending loss, dispersion characteristics and fraction of power flow are calculated to determine the impacts for rotating the triangular core. The porous fiber represented here has a hybrid design in the core area which includes circular rings with central triangular air hole arrangement. The cladding of the investigated fiber has a hexagonal array of air hole distribution. For optimum parameters the reported hybrid porous core fiber shows a flat EML of ±0.000416 cm⁻¹ from 1.5 to 5 terahertz (THz) range and a near zero dispersion of 0.4±0.042 ps/THz/cm from 1.25 to 5.0 THz. Negligible confinement and bending losses are reported for this new type of hybrid porous core design. With improved concept of air hole distribution and exceptional waveguide properties, the reported porous core fiber can be considered as a vital forwarding step in this field of research.
Źródło:
International Journal of Electronics and Telecommunications; 2017, 63, 1; 25-31
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies