Diffuse scattering model for human brain wave (Alpha) propagation prediction during meditation inside a temple, through ray tracing, a hypothetical study

Electromagnetic radio waves have been propagating for billions of years through the universe since the beginning of time. Electromagnetic radio wave propagation and the communication revolution it spawned, however are products of the twentieth century. Radio propagation in a particular environment is a complex, multipath phenomenon which involves several different mechanisms. According to a traditional, simplified approach, two major urban propagation mechanisms are identified over-roof-top (ORT) or vertical propagation (VP), where one major radial path undergoes multiple diffractions on building tops, and lateral propagation (LP) where several rays reflect/diffract all vertical building walls/edges according to the geometrical Optics (GO) rules before reaching the receiver.

Thermal Performance Assessment of a Wall Made of Lightweight Concrete Blocks with Recycled Brick and Ground Polystyrene

Hollow concrete masonry blocks made of low strength self-compacting concrete with recycled crushed brick and ground polystyrene as an aggregate (RBC-EP blocks), and their expected structural role as masonry infill in steel frames, has been confirmed in previous research studies, thus the extensive investigation of thermal properties is presented in this paper to fully approve their potential application in practice. The Heat Flow and Temperature Based Method was used to conduct in-situ measurements of the wall thermal transmittance (U-value). The experimental U-values of the wall without insulation varied from 1.363 to 1.782 W/m2·K, and the theoretical value was calculated to be 2.01 W/m2·K. Thermal conductivity of the material used for making RBC-EP blocks was measured in a laboratory by using a heat flow meter instrument. To better understand the thermal performance characteristics of a wall constructed from RBC-EP blocks, a comparison with standard materials currently used and found on the market was performed. Walls constructed from RBC-EP blocks show an improvement of building technology and environmentally based enhancement of concrete blocks, since they use recycled materials. They can replace standard lightweight concrete blocks due to their desired mechanical properties, as well as the better thermal performance properties compared to commonly used materials for building walls.

Assessment of Wall Salinity in the Selection of Renovation Plaster Systems

This article presents issues related to assessing the degree of wall salinity to select plaster systems for renovations of damp building walls. The most commonly used salt concentration tests pose many difficulties. If used uncritically, they risk failing to select the right system or its incorrect make. The accuracy of the colorimetric method for testing chloride, nitrate, and sulphate content was analysed to exemplify the magnitude of the problem. Both multi-salt solutions of known concentrations and unknown composition extracted from drillings in the walls of a historical facility were examined. A comparative methodology using ion chromatography as a standard was employed in the research. The analytical methods and the selected modules of the „Statistica” software were used to analyse data and present the results. The colorimetric method has been shown to distort salt concentration values, posing a risk of unsuccessful repair work on high-salinity walls. A method for determining the correction reducing the measurement error has been proposed. The factors affecting the error were also mentioned. Attention has also been drawn to the resolution and application of a method with a correct concentration range intended to improve work efficiency and optimize the costs incurred in renovating the salty wall.

Finding a Fair Heat Settlement Model

In this report, we investigate optimal strategies for fair heat settlement schemes in apartment buildings heated by externally powered radiators and pipes. We use mathematical modelling to predict the distribution of heat among apartments taking into account heat flow through the building walls and external conditions. We use both deterministic and statistical approaches.

Lime compounds for restoration and decoration of building walls

Information on the effect of a polysilicate solution obtained by mixing liquid glass with a silicic acid sol on the structure formation of lime compositions is presented. It was revealed that the amount of specific heat released when lime is wetted with a polysilicate solution is greater than when lime is wetted with water. This is due to the additionally released heat due to the chemical interaction of lime with polysilicate solution. It was found that the introduction of a polysilicate solution accelerates the development of plastic strength. For comparison, we used liquid glass and a sol of silicic acid as an additive. The synergistic effect of the influence of the polysilicate solution on the structure formation of lime finishing compositions was established, which manifests itself in the acceleration of the set plastic strength in comparison with silica sol and water glass. It has been established that the introduction of a polysilicate solution into the lime mixture formulation contributes to an increase in the resistance to slipping of the finishing layer. The optimal thickness of the finishing layer was determined, which is 20 mm, at which sliding from the vertical surface is not observed.