Wyniki wyszukiwania - BazTech

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Image velocimetry and statistical analysis of a mesh-coupled axial blade distributor for mass transfer in a swirling bed

Javed Muhammad Asif, Shukrullah Shazia, Naz Muhammad Yasin, Sarfraz Raja Adil

Journal of Theoretical and Applied Mechanics

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2020

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Vol. 58 nr 3

779--790

EN

A mesh-coupled axial blade distributor was tested for fluidization of particles in a swirling fluidized bed. The bed velocity was estimated experimentally using a high-speed imaging device and MATLAB supported particle image velocimetry (PIV). The bed velocity was also predicted statistically with a response surface analysis method. During statistical analysis, the confidence interval of bed velocity remained between 0.49485 and 0.49998. The bed velocity was measured about 0.49741m/s and 0.538m/s through experimental and statistical methods, respectively. The experimental and statistical analysis revealed similar bed weights and superficial velocities with a slight difference of 6.4◦ in blade angles.

2

Response Surface Analysis of the Compressive Strength of Self-Compacting Concrete Incorporating Metakaolin

Busari Ayobami, Dahunsi Bamidel, Akinmusuru Joseph, Loto Tolulope, Ajayi Samuel

Advances in Science and Technology. Research Journal

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2019

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Vol. 13, no 2

7--13

EN

This research developed a mathematical model and optimization of materials for the development of metakaolin self-compacting concrete. This is in a bid to reduce the overall material quantity and cost towards sustainable infrastructural construction. To achieve the aim of this research, Response Surface Analysis (RSM) was used. Kaolinitic clay was De-hydroxylated at 750°C to form metakaolin. This was used as a partial replacement for cement at 0%, 5%, 10%, 15%, 20% and 25% weight of Portland limestone cement. Both strength and rheology properties of the developed metakaolin self-compacting concrete were assessed. To this end, slump flow, L-Box test and V-funnel test were carried out alongside the compressive strength using relevant standard. The result of the research revealed that at 15% addition of metakaolin the slump flow, passing ability and filling ability was unsatisfactory according to EFNARC standard. From the numerical optimization of the compressive strength, the maximum predicted compressive strength of 44.35 N/mm2 was obtained. At a low value of metakaolin addition (5–15%), the compressive strength increased as the age of the concrete increased from 3–150 days. The age with the optimum mechanical strength formation was 110 days with metakaolin addition of 52.73 kg. The result of this research provide a database for Engineers, Researchers and Construction workers on the optimum metakaolin required to achieve satisfactory mechanical strength in metakaolin self-compacting concrete.

3

Ryszard Zieliński’s contribution to statistical optimization and fixed-precision estimation

Męczarski M.

Mathematica Applicanda

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2012

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Vol. 40, No. 2

107--111

EN

Professor Ryszard Zieliński's results in stochastic approximation, extremal experimental design in the framework of response surface analysis and fixed-precision set estimation are outlined. First, he proposed a randomized version of Fabian's (1967) gradient estimate in the Kiefer-Wolfowitz procedure, which reduced the number of required observations and improved the rate of convergence. Second, when considering response surface analysis and experimental designs for the gradient estimation, he constructed a randomized simplex design which resulted in the unbiased estimator. Third, he gave a method to construct confidence sets with prescribed accuracy (i. e. the width and the confidence level) by sampling independent copies of a process of interest. Professor Ryszard Zieliński's results in stochastic approximation, extremal experimental design in the framework of response surface analysis and fixed precision set estimation are outlined. First, he proposed a randomized version of Fabian's (1967) gradient estimate in the Kiefer-Wolfowitz procedure, which reduced the number of required observations and improved the rate of convergence. Second, when considering response surface analysis and experimental designs for the gradient estimation, he constructed a randomized simplex design which resulted in the unbiased estimator. Third, he gave a method to construct confidence sets with prescribed accuracy (i. e. the width and the confidence level) by sampling independent copies of a process of interest.

4

Preliminary optimization of direct amination of 1-(2,6-dimethylphenoxy)-2-propanol. synthesis of 1-(2,6-dimethylphenoxy)-2-aminopropane

Leś A., Kajl M., Szelejewski W.

Polish Journal of Applied Chemistry

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2005

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Vol. 49, nr 3

195-203

EN

Preliminary steps were reported of optimization of catalytic amination of 1-(2,6-dimethylophenoxy)-2-propanol in our new synthesis of 1-(2,6-dimethylphenoxy)-2-aminopropane (mexiletine). In our search for optimal conditions a series of experiments were performed based on the concept of fractional factorial design. A detailed statistical analysis of reaction responses indicated necessary modifications of the synthesis. Elevated temperatures and the use of a more efficient catalyst were found necessary in order to use direct amination in industrial synthesis of pharmaceutically important amine from commercially available alcohol.