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

Trilinear Higgs couplings in the two Higgs doublet model with CP violation

We carry out a detailed analysis of the general two Higgs doublet model with CP violation. We describe two different parametrizations of this model, and then study the Higgs boson masses and the trilinear Higgs couplings for these two parametrizations. Within a rather general model, we find that the trilinear Higgs couplings have a significant dependence on the details of the model, even when the lightest Higgs boson mass is taken to be a fixed parameter. We include radiative corrections in the one-loop effective potential approximation in our analysis of the Higgs boson masses and the Higgs trilinear couplings. The one-loop corrections to the trilinear couplings of the two Higgs doublet model also depend significantly on the details of the model, and can be rather large. We study quantitatively the trilinear Higgs couplings, and show that these couplings are typically several times larger than the corresponding Standard Model trilinear Higgs coupling in some regions of the parameter space. We also briefly discuss the decoupling limit of the two Higgs doublet model.Comment: 23 pages, 15 figures. v2: References added, version to appear in PR

Selection of productivity improvement techniques via mathematical modeling

This paper presents a new mathematical model to select an optimal combination of productivity improvement techniques. The proposed model of this paper considers four-stage cycle productivity and the productivity is assumed to be a linear function of fifty four improvement techniques. The proposed model of this paper is implemented for a real-world case study of manufacturing plant. The resulted problem is formulated as a mixed integer programming which can be solved for optimality using traditional methods. The preliminary results of the implementation of the proposed model of this paper indicate that the productivity can be improved through a change on equipments and it can be easily applied for both manufacturing and service industries

Nutrient Chemo Prevent to Enhance Cancer Prevention: A Review

Introduction: Nutrients Chemoprevention is dietary compounds to reduce the incidence of cancer, and the dietary compounds could be fibers, nutrients, or vitamins.Purpose: the aim of this integrative literature review to determine effect of nutrients chemo-prevents to reduce risk of cancer.Design: integrative literature review.Method: the electronic databases of CINAHL with full text MEDLINE with full text for article published between 2009 and 2014.Finding: most of nutrients chemo prevents reduce risk some type of cancer. Conclusion: review the nutrients chemo prevents enhance cancer prevention and reduce risk of cancer, so all of country's must be educate the people about the important the nutrition to prevent cancer and enhance health care provider to apply this finding when they make education for the patient or clients, and this topic need more study to become evidence based practice. Keywords: Chemo Prevent, Cancer Prevention, Dietary Intake

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

Computational modeling of sublattice magnetizations of nano-magnetic layered materials

In the present work, we model the salient magnetic properties of the alloy layered ferrimagnetic nanostructures $[Co_{1-c}Gd_c]_{\ell^{\prime}}[Co]_\ell[Co_{1-c}Gd_c]_{\ell^{\prime}}$ between magnetically ordered cobalt leads. The effective field theory (EFT) Ising spin method is used to compute reliable $J_{Co-Co}$ and $J_{Gd-Gd}$ exchange values for the pure cobalt and gadolinium materials in comparison with experimental data. Using the combined EFT and mean field theory (MFT) spin methods, the sublattice magnetizations of the $Co$ and $Gd$ sites on the individual hcp basal planes of the layered nanostructures, are calculated and analyzed. The sublattice magnetizations, effective magnetic moments per site, and compensation characteristics on the individual hcp atomic planes of the embedded nanostructures are presented as a function of temperature and the thicknesses of the layered ferrimagnetic nanostructures, for different stable eutectic concentrations $c\leq$ 0.5. In the absence of first principles calculations for these basic physical variables for the layered nanostructures between cobalt leads, the combined EFT and MFT approach, and appropriate magnetic modeling of the well-defined interfaces of these systems, yield the only available information for them at present. These magnetic variables are necessary for spin dynamic computations, and for the ballistic magnon transport across embedded nanojunctions in magnonics. The model is general, and may applied directly to other composite magnetic elements and embedded nanostructures