Lensing observables: Massless dyonic vis-\`a-vis Ellis wormhole

Stable massless wormholes are theoretically interesting in their own right as well as for astrophysical applications, especially as galactic halo objects. Therefore, the study of gravitational lensing observables for such objects is of importance, and we do here by applying the parametric post-Newtonian method of Keeton and Petters to massless dyonic charged wormholes of the Einstein-Maxwell-Dilaton field theory and to the massless Ellis wormhole of the Einstein minimally coupled scalar field theory. The paper exemplifies how the lensing signatures of two different solutions belonging to two different theories could be qualitatively similar from the observational point of view. Quantitative differences appear depending on the parameter values. Surprisingly, there appears an unexpected divergence in the correction to differential time delay, which seems to call for a review of its original derivation.Comment: 16 pages, 7 figure

Modified fiber cement panels for civil construction

© The Authors, published by EDP Sciences, 2017.The authors investigated the influence of modifying agents, based on the realization of three-factor plan of the second-order, on physico-mechanical properties and durability of fiber cement boards based on cellulose fibers

Physical and mechanical properties of fiber reinforced gypsum-based composite

© 2019 IOP Publishing Ltd. All rights reserved. Formulations of effective gypsum-fiber and gypsum-cement-fiber materials modified with active mineral additives and superplasticizer have been developed in the present experimental work. The influence of the type and length of reinforcing polypropylene fiber, the conditions of hardening and molding on the physical and mechanical properties of the specimens was studied

Investigation of mechanical properties of fiber-cement board reinforced with cellulosic fibers

© 2019 IOP Publishing Ltd. All rights reserved. The article presents experimental research on the development of the optimal composition of cement-fibrous composite material for the manufacture of autoclaved fiber-cement boards with high physical, mechanical and economic parameters. The effect of the cement-sand ratio of the matrix, the specific surface area of the sand and the cellulosic fibers content on the physical and technical properties of the material is shown. It is established that the optimum cement-sand ratio of the matrix associated with a specific surface area of quartz sand 310 m2/kg is 1:2. The optimal content of cellulosic fibers according to the criterion of increasing the strength is 5-7.5%

Physical and mechanical properties of fiber reinforced gypsum-based composite

© 2019 IOP Publishing Ltd. All rights reserved. Formulations of effective gypsum-fiber and gypsum-cement-fiber materials modified with active mineral additives and superplasticizer have been developed in the present experimental work. The influence of the type and length of reinforcing polypropylene fiber, the conditions of hardening and molding on the physical and mechanical properties of the specimens was studied

Investigation of mechanical properties of fiber-cement board reinforced with cellulosic fibers

© 2019 IOP Publishing Ltd. All rights reserved. The article presents experimental research on the development of the optimal composition of cement-fibrous composite material for the manufacture of autoclaved fiber-cement boards with high physical, mechanical and economic parameters. The effect of the cement-sand ratio of the matrix, the specific surface area of the sand and the cellulosic fibers content on the physical and technical properties of the material is shown. It is established that the optimum cement-sand ratio of the matrix associated with a specific surface area of quartz sand 310 m2/kg is 1:2. The optimal content of cellulosic fibers according to the criterion of increasing the strength is 5-7.5%

Modified fiber cement panels for civil construction

© The Authors, published by EDP Sciences, 2017.The authors investigated the influence of modifying agents, based on the realization of three-factor plan of the second-order, on physico-mechanical properties and durability of fiber cement boards based on cellulose fibers

Modified fiber cement panels for civil construction

© The Authors, published by EDP Sciences, 2017.The authors investigated the influence of modifying agents, based on the realization of three-factor plan of the second-order, on physico-mechanical properties and durability of fiber cement boards based on cellulose fibers

Modified fiber cement panels for civil construction

© The Authors, published by EDP Sciences, 2017.The authors investigated the influence of modifying agents, based on the realization of three-factor plan of the second-order, on physico-mechanical properties and durability of fiber cement boards based on cellulose fibers