Development of High Thermal Stability Geopolymer Composites Enhanced by Nano Metakaolin

This paper deals with study of thermal stability of geopolymer composites enhanced by nano metakaolin materials (NMK) and exposed to high firing temperature up to 1000 °C. The main geopolymer made up of water cooled slag having various kaolin ratios.  The activators used are Na2SiO3 and NaOH in the ratio of 3:3. The thermo-physical, micro-structural and mechanical properties of the geopolymers before and after the exposure to elevated temperatures of 300, 500, 600 800 and 1000 °C have been investigated. The fire shrinkage of the geopolymer specimens increased by increasing temperature up to 1000 oC. Also, the fire shrinkage increased slowly up to 500 °C. The mechanical strength of geopolymer specimens increased with temperature up to 500 oC. The good thermo-physical and mechanical properties for these geopolymer composites increase the possibility of vast application of these eco-friendly materials in construction sectors

Alkali Activated Eco-friendly Metakaolin/Slag Geopolymer Building Bricks

Alkali activation of alumino-silicate materials is a complex chemical process evolving dissolution of raw materials, transportation or orientation and polycondensation of the reaction products. This study explores the physico-mechanical characteristics of geopolymer bricks using eco-friendly slag/metakaolin binder. Alkaline activation of slag – metakaolin binder of geopolymer brick results in formation of C-A-S-H as well as N-A-S-H gel, which adopts different structures depending on the nature of the alkaline activator. Activators used are 10% NaOH solution in addition to 5% liquid sodium silicate both used from the total binder weight), Geopolymer bricks prepared by partial binder substitution of metakaolin (fired kaolin) by water cooled slag in the ratio from 0 up to 100 %, while the used fine sand(passing 1 mm) in the ratio of 15% from the total weight. The properties of the produced geopolymer bricks have been studied through measurement of compressive strength, water absorption, FTIR, XRD and SEM imaging. Results demonstrate the possibility of substitution of metakaolin by water cooled amorphous slag materials in producing geopolymer bricks with superior properties where an increase in mechanical strength with water cooled slag increase up to 40 %  was noticed giving compressive strength values exceed 70 MPa which can be used for production of  heavy duty  bricks which can be applied in a severe weathering condition as well as special purposes building applications, however further increase results in lowering strength values as a  but still exceed 30 MPa after 28 days of hydration. Keywords: slag, metakaolin, bricks, eco-friendly, sustainability

On the stationary vibrations of a rectangular plate subjected to stress prescribed partially at the circumference

The stationary periodical problem of a vibrating rectangular plate, stressed at a segment while fixed elsewhere at one of its edges, is considered. Using the finite Fourier transformation, the problem is converted to a singular integral equation that in turn can be reduced to an infinite system of algebraic equations. The truncation of the algebraic system is justified

Parametrically controlling solitary wave dynamics in modified Kortweg-de Vries equation

We demonstrate the control of solitary wave dynamics of modified Kortweg-de Vries (MKdV) equation through the temporal variations of the distributed coefficients. This is explicated through exact cnoidal wave and localized soliton solutions of the MKdV equation with variable coefficients. The solitons can be accelerated and their propagation can be manipulated by suitable variations of the above parameters. In sharp contrast with nonlinear Schr\"{o}dinger equation, the soliton amplitude and widths are time independent.Comment: 4 pages, 5 eps figure

Development of High Thermal Stability Geopolymer Composites Enhanced by Nano Metakaolin

This paper deals with study of thermal stability of geopolymer composites enhanced by nano metakaolin materials (NMK) and exposed to high firing temperature up to 1000 °C. The main geopolymer made up of water cooled slag having various kaolin ratios.  The activators used are Na2SiO3 and NaOH in the ratio of 3:3. The thermo-physical, micro-structural and mechanical properties of the geopolymers before and after the exposure to elevated temperatures of 300, 500, 600 800 and 1000 °C have been investigated. The fire shrinkage of the geopolymer specimens increased by increasing temperature up to 1000 oC. Also, the fire shrinkage increased slowly up to 500 °C. The mechanical strength of geopolymer specimens increased with temperature up to 500 oC. The good thermo-physical and mechanical properties for these geopolymer composites increase the possibility of vast application of these eco-friendly materials in construction sectors

AI-based analysis of super-resolution microscopy: Biological discovery in the absence of ground truth

The nanoscale resolution of super-resolution microscopy has now enabled the use of fluorescent based molecular localization tools to study whole cell structural biology. Machine learning based analysis of super-resolution data offers tremendous potential for discovery of new biology, that by definition is not known and lacks ground truth. Herein, we describe the application of weakly supervised learning paradigms to super-resolution microscopy and its potential to enable the accelerated exploration of the molecular architecture of subcellular macromolecules and organelles.Comment: 14 pages, 3 figure

Obstructed D-Branes in Landau-Ginzburg Orbifolds

We study deformations of Landau-Ginzburg D-branes corresponding to obstructed rational curves on Calabi-Yau threefolds. We determine D-brane moduli spaces and D-brane superpotentials by evaluating higher products up to homotopy in the Landau-Ginzburg orbifold category. For concreteness we work out the details for lines on a perturbed Fermat quintic. In this case we show that our results reproduce the local analytic structure of the Hilbert scheme of curves on the threefold.Comment: 44 pages; v3: typos correcte