Wyniki wyszukiwania - BazTech

1

Composite relaxed resolvent operator and Yosida approximation operator for solving a system of Yosida inclusions

Ahmad R., Mishra V. N., Ishtyak M., Rahaman M.

Journal of Applied Analysis

|

2018

|

Vol. 24, nr 2

185--195

EN

In this paper, we first study a composite relaxed resolvent operator and prove some of its properties. After that, we introduce a Yosida approximation operator based on the composite relaxed resolvent operator and demonstrate some properties of the Yosida approximation operator. Finally, we obtain the solution of a system of Yosida inclusions by applying these concepts.We construct a conjoin example in support of many concepts derived in this paper. Our concepts and results are new in the literature and can be used for further research.

2

Influence of Ta2O5 doping on mechanical and biological properties of silicate glass-ceramics

Riaz M., Zia R., Saleemi F., Bashir F., Ahmad R., Hossain T.

Materials Science Poland

|

2016

|

Vol. 34, No. 1

13--18

EN

The mechanical properties of silicate glass-ceramics were evaluated based on the compressive strength tests. It was found that addition improved densification, refinement of the microstructure and toughening of the bodies. The maximum compressive strength of the bodies with 1 mol% Ta2O5 was increased 3-fold (245.92 ±0.3 MPa) in comparison to undoped glass-ceramics which was measured to be 89.04 ±0.3 MPa, while for 3 mol% it became 4-fold (387.12 ±0.4 MPa) greater. The addition of Ta2O5 stabilized the system by controlling the biodegradation of the glass-ceramics. It effectively depressed the apatite formation as by addition of 3 mol% Ta2O5 no apatite layer was observed. It may be concluded from this study that mechanical and physical properties can be improved by the addition of Ta2O5 , but at a cost of bioactivity. Still the optimized composition having Ta2O5 ≤ 1 mol% may provide appropriate strength of biomaterials for high load bearing applications.

3

Set-valued variational-like inclusions with H -eta-accretive operators in Banach spaces

Ahmad R.

Journal of Applied Analysis

|

2011

|

Vol. 17, nr 1

105-117

EN

In this work, a new class of set-valued variational-like inclusions involving H - η-accretive operators is introduced and studied. A new iterative procedure for computing approximate solutions for the class of set-valued variational-like inclusions and convergence results are established.

4

Effect of vortex runner gating system on the mechanical strength of Al-12SI alloy castings

Ahmad R., Hashim M. Y.

Archives of Metallurgy and Materials

|

2011

|

Vol. 56, iss. 4

991-991

EN

Gating system design is an essential element in casting process which affects significantly the molten metal flow behavior, heat transfer and solidification of the melt. Optimum gating design will lead to a good quality of casting product. One of the major components in gating system is runner. This study was conducted to determine the effect of vortex runner diameter gating system on the mechanical strength of Al-12Si alloy casting. Simulation was conducted to study the behavior of the fluid flow and the results obtained showed close agreement with the results obtained from the experiment. Experimental results showed that the casting product with bigger vortex runner diameter gating system led to the improvement of average bending strength.

PL

Układ wlewowy to podstawowy element w procesie odlewania, który znacząco wpływa na płynięcie ciekłego metalu, transport ciepła oraz krzepnięcie metalu. Optymalny układ wlewowy gwarantuje dobra jakość odlanego produktu. Jednym z głównych elementów układu wlewowego jest kanał wlewowy. Celem pracy było zbadanie wpływu średnicy kanału układu wlewowego na wytrzymałosc mechaniczna odlewów ze stopu Al-12Si. Celem zbadania zachowania przecieczy przeprowadzono symulacje i otrzymane wyniki wykazują dobrą zgodność z wynikami otrzymanymi doświadczalnie. Wyniki doswiadczeń pokazały, że zastosowanie większej srednicy kanału układu wlewowego prowadzi do poprawy średniej wytrzymałości odlewów na zginanie.

5

Integration of vision based image processing for multi-axis CNC machine tool safe and efficient trajectory generation and collision avoidance

Ahmad R., Tichadou S., Hascoet J.-Y.

Journal of Machine Engineering

|

2010

|

Vol. 10, No. 4

53--65

EN

Demand of high speed production not only increases the complexity of today's CNC process, but also increases the risks and possibility of collision because of the difference between real (machining) and virtual scenes (CAD/CAM process). Idea here is to make this process more intelligent by processing image taken from the real or virtual machine scenes. Identify objects (already known in the CAD database), obtain safe and efficient trajectories that will modify the previous known trajectories from the CAM systems and will be used finally in real machining environments. This work more focuses to improve trajectory generation, collision avoidance and communication in CAD/CAM systems by image processing technique. Safe and Efficient Trajectory (SET) algorithm for point trajectory is discussed along with its extended version for object trajectory known as Rectangular Enveloped object Safe and Efficient Trajectory (RESET) algorithm that will perfectly generate safe un-functional trajectories [3] for multi-axis machine tool envelop. Meanwhile scene objects are detected and identified by image processing tool while trajectory and setup is optimized and improved accordingly in order to avoid collision. This generated trajectory can be used for setup correction before and after production or for "real times/online" production. Finally work has been validated through real and virtual machine scene images.