scholarly journals Pressed non-fired bricks from phosphogypsum waste for non-load bearing wall

2021 ◽  
Vol 30 (3) ◽  
Author(s):  
Zied Kammoun
Keyword(s):  
Groundwater Pollution ◽  
Mechanical Tests ◽  
Low Energy ◽  
Mechanical Resistance ◽  
Load Bearing ◽  
Physical Chemical ◽  
The World ◽  
Fired Bricks ◽  
Phosphogypsum Waste ◽  
Radionuclide Activity

In several countries of the world, phosphogypsum represents a large quantity of waste that poses serious problems of environmental and groundwater pollution. This study aims at recovering phosphogypsum, in its raw state without treatment, in the manufacture of non-load-bearing non-fired bricks. The study starts with the analysis of the radionuclide activity of the materials constituting the bricks, in particular phosphogypsum, in order to avoid any human health problems after the manufacture and use of the bricks. Then, several compositions are tested with several preservation methods in order to optimize the composition. The physical, chemical and mechanical resistance is determined. The results show the possibility to produce non-load-bearing bricks based on untreated phosphogypsum which comply with the standards requirements, using low energy. Indeed, among the considered mixtures, two compositions (60% of PG and of 75% of PG) perfectly verify the physical and mechanical tests. Also, storage of the mixtures for two days in the laboratory and then three days in an oven at 70°C, allows to obtain the best resistance to compression. Thus, the obtained resistance is much higher than the minimum value required for non-load-bearing bricks.

scholarly journals Ultrasonic, Molecular and Mechanical Testing Diagnostics in Natural Fibre Reinforced, Polymer-Stabilized Earth Blocks

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
C. Galán-Marín ◽  
C. Rivera-Gómez ◽  
F. Bradley
Keyword(s):  
Soil Stabilization ◽  
Ultrasonic Pulse Velocity ◽  
Mechanical Tests ◽  
Pulse Velocity ◽  
Mechanical Resistance ◽  
Chemical Compositions ◽  
Natural Polymer ◽  
Natural Polymers ◽  
X Ray ◽  
Earth Blocks

The aim of this research study was to evaluate the influence of utilising natural polymers as a form of soil stabilization, in order to assess their potential for use in building applications. Mixtures were stabilized with a natural polymer (alginate) and reinforced with wool fibres in order to improve the overall compressive and flexural strength of a series of composite materials. Ultrasonic pulse velocity (UPV) and mechanical strength testing techniques were then used to measure the porous properties of the manufactured natural polymer-soil composites, which were formed into earth blocks. Mechanical tests were carried out for three different clays which showed that the polymer increased the mechanical resistance of the samples to varying degrees, depending on the plasticity index of each soil. Variation in soil grain size distributions and Atterberg limits were assessed and chemical compositions were studied and compared. X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), and energy dispersive X-ray fluorescence (EDXRF) techniques were all used in conjunction with qualitative identification of the aggregates. Ultrasonic wave propagation was found to be a useful technique for assisting in the determination of soil shrinkage characteristics and fibre-soil adherence capacity and UPV results correlated well with the measured mechanical properties.

scholarly journals MODELING OF SOIL LOAD-BEARING CAPACITY AS A FUNCTION OF SOIL MECHANICAL RESISTANCE TO PENETRATION

2015 ◽  
Vol 39 (4) ◽  
pp. 1036-1047 ◽  
Author(s):  
Cícero Ortigara ◽  
Moacir Tuzzin de Moraes ◽  
Henrique Debiasi ◽  
Vanderlei Rodrigues da Silva ◽  
Julio Cezar Franchini ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Agricultural Soils ◽  
Total Porosity ◽  
Soil Bulk Density ◽  
Mechanical Resistance ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Preconsolidation Pressure ◽  
Soil Load ◽  
Resistance To Penetration

Estimation of soil load-bearing capacity from mathematical models that relate preconsolidation pressure (σp) to mechanical resistance to penetration (PR) and gravimetric soil water content (U) is important for defining strategies to prevent compaction of agricultural soils. Our objective was therefore to model the σp and compression index (CI) according to the PR (with an impact penetrometer in the field and a static penetrometer inserted at a constant rate in the laboratory) and U in a Rhodic Eutrudox. The experiment consisted of six treatments: no-tillage system (NT); NT with chiseling; and NT with additional compaction by combine traffic (passing 4, 8, 10, and 20 times). Soil bulk density, total porosity, PR (in field and laboratory measurements), U, σp, and CI values were determined in the 5.5-10.5 cm and 13.5-18.5 cm layers. Preconsolidation pressure (σp) and CI were modeled according to PR in different U. The σp increased and the CI decreased linearly with increases in the PR values. The correlations between σp and PR and PR and CI are influenced by U. From these correlations, the soil load-bearing capacity and compaction susceptibility can be estimated by PR readings evaluated in different U.

scholarly journals The concept of creating thrust based on angular momentum change

2021 ◽  
Author(s):  
Sergei Kupreev
Keyword(s):  
Angular Momentum ◽  
Vacuum Chamber ◽  
Loop Quantum Gravity ◽  
Low Energy ◽  
Practical Implementation ◽  
Material Body ◽  
The World ◽  
Classical And Quantum Mechanics ◽  
Physical Principles ◽  
Kinetic Moment

Abstract The change in the kinetic moment of a material body is considered regarding to classical and quantum mechanics. The possibility of creating the propulsion system in terms of energy efficiency exceeding the photon engine has been theoretically proved. The proposed new principle of motion is based on the law of conservation of angular momentum and is fully consistent with the basic fundamental laws of physics. It is proposed to use the emission/absorption of streams of low-energy particles with spin in the direction perpendicular to the movement of the material body. The practical implementation of this idea is confirmed by the presence of promising approaches to solving the problem of quantizing gravity (string theory, loop quantum gravity, etc.) recognized by the world scientific community and by the successful results of experiments conducted by the authors with the motion of bodies in a vacuum chamber. The proposed idea, the examples and experiments has given grounds for the formation of new physical concepts of the speed, mass and inertia of bodies. The obtained results can be used in experiments to search for elementary particles with low energy, to explain a number of physics phenomena and to develop transport of objects based on new physical principles.

scholarly journals Jan Evangelista Purkinje (1797-1869)

2021 ◽  
Vol 11 (22) ◽  
pp. 81-85
Author(s):  
Tamás Fazekas
Keyword(s):  
Middle Layer ◽  
Conduction System ◽  
Cardiac Conduction ◽  
Animal Tissues ◽  
Basic Principles ◽  
Cellular Physiology ◽  
Medical Language ◽  
Physical Chemical ◽  
Claude Bernard ◽  
The World

Being a chairman and professor of physiology in Breslau/Wroclaw till 1850, Jan Evangelista Purkinje (1797-1869) made many crucial discoveries/experiments with the new advanced microscopy and histology techniques. He established the first institute of the physiology of the world (1839) and founded the basic principles and framework of cellular physiology (protoplasmic concept) both in plant and animal tissues. Purkine discovered and described (first in Polish, 1839) the extensive terminal network of the cardiac conduction system. Its paradigmatic discovery was presented in the last two 15-page German article in 1845, which was immediately translated into English by Sir William Withey Gull (1816-1880), an extraordinary physician to the queen and Prince of Wales. In 1837, he made his other famous discovery of Purkine cells, a giant flak-shaped nerve cell forming the middle layer of the cerebellum. His combination of physical, chemical, and microscopic observations made him the father of modern experimental physiology and predecessor of the legendary French scientist/biologist, Claude Bernard (1813-1878). Purkinje as a Czech and Slav patriot advocated cultural collaboration of Slav nations and promoted understanding between the nations of the Habsburg monarchy. His life and personality is also an inspiration on how to be a truly humanistic European and yet, a highly responsible, convinced patriot. He was a pioneer of the Czech medical language. His achievements are possibly best documented by this rhyme of Goethe: „…and should you fail to understand let Purkinje give you a hand.” True also for our times (cit by Zarsky).

scholarly journals Analyzing the Structural Properties of Fire Clay Bricks After Adding Cigarette Filters

2020 ◽  
Vol 16 ◽  
Keyword(s):  
Natural Resources ◽  
Structural Properties ◽  
Industrial Production ◽  
Load Bearing ◽  
Biodegradable Waste ◽  
Clay Bricks ◽  
Cigarette Butts ◽  
Two Samples ◽  
The World ◽  
Fire Clay

Cigarette filters are one of the most littered objects in the world that damage the environment. Incorporation in construction bricks offers the prospect of limiting damage and solves the recyclability problem for a typical non-biodegradable waste. This paper aims to explore that prospect, by adding cigarette filters in the production of two samples of fired clay bricks with the cigarette filters comprising 5% and 10% of the volume. The mixing and molding processes were done manually which had an effect on the bricks when tested, The results of testing were corresponding with those of previous studies (outside Egypt), however, only one sample of 5% Cigarette butts volume bricks complied with the Egyptian standards for bricks used in non-load bearing uses. The industrial production of these bricks is highly recommended as it will surpass the required Egyptian standards, save a significant amount of natural resources and eliminate cigarette waste.

Knowledge argument

2018 ◽  
Author(s):  
Torin Alter
Keyword(s):  
Biological Sciences ◽  
Colour Vision ◽  
Thought Experiment ◽  
Natural World ◽  
Knowledge Argument ◽  
Frank Jackson ◽  
Black And White ◽  
Television Monitor ◽  
Physical Chemical ◽  
The World

The knowledge argument is an argument against physicalism, the view that the world is wholly physical. It was developed by Frank Jackson (1943–) and is based on the following thought experiment. Everything that can be known through the physical, chemical, and biological sciences – the complete physical truth – has been discovered. Mary is a brilliant scientist who is raised in a black-and-white room. She has never had colour experiences. But she learns the complete physical truth, which includes the completed science of colour vision, by reading books and watching lectures on a black-and-white television monitor. Then she leaves the room and sees colours. Jackson’s argument runs roughly as follows. When Mary leaves the room, she learns something new. She learns what it is like to see in colour. Evidently, the complete physical truth is not the complete truth about the world. Ergo, physicalism is false. Some react by denying that Mary learns anything when she leaves the room. Others react by accepting that she learns something but denying that this refutes physicalism. Still others accept the argument as sound. The ensuing discussion has led to a variety of insights about consciousness and its place in the natural world.

scholarly journals Dynamic thermal response of low-energy residential buildings based on in-wall measurements

2019 ◽  
Vol 111 ◽  
pp. 04002 ◽  
Author(s):  
Kyriaki Foteinaki ◽  
Rongling Li ◽  
Alfred Heller ◽  
Morten Herget Christensen ◽  
Carsten Rode
Keyword(s):  
Air Temperature ◽  
Energy Use ◽  
Residential Buildings ◽  
Measurement Data ◽  
Thermal Response ◽  
Low Energy ◽  
Space Heating ◽  
Internal Wall ◽  
Load Bearing ◽  
Concrete Elements

This study analysed the dynamic thermal response of a low-energy building using measurement data from an apartment block in Copenhagen, Denmark. Measurements were collected during February and July 2018 on space heating energy use, set-points, room air temperature and temperature from sensors integrated inside concrete elements, i.e. internal walls and ceiling, at different heights and depths. The heating system was controlled by the occupants. During February, there were unusually high set-points for some days and a regular heating pattern for some other days. Overheating was observed during July. A considerable effect of solar gain was observed both during winter and summer months. The room air temperature fluctuations were observed at a certain extent inside the concrete elements; higher in the non-load-bearing internal wall, followed by the load-bearing internal wall and lastly by the ceiling. The phenomenon of delayed thermal response of the concrete elements was observed. All internal concrete masses examined may be regarded as active elements and can contribute to the physically available heat storage potential of the building. The study provides deep insight into the thermal response of concrete elements in low-energy residential buildings, which should be considered when planning a flexible space heating energy use.

Effect of Fiber Form and Volume Fraction on Fiber-Reinforced Biomimicked Composites

2012 ◽  
Author(s):  
Hussain Alghahtani ◽  
Seyed M. Allameh
Keyword(s):  
Fracture Toughness ◽  
Carbon Fibers ◽  
Volume Fraction ◽  
Structural Materials ◽  
Mechanical Tests ◽  
Fiber Reinforced ◽  
Structural Composites ◽  
Load Bearing ◽  
Short Forms ◽  
Four Point Bending

Biomimicked composites have shown to be superior to monolithic structural materials. However, they need reinforcement to replace conventional load-bearing structural composites. Carbon Fibers in long and short forms were used as reinforcement in biomimicked composites. Mechanical tests including four point bending were conducted to determine the effects of form and volume fraction of fibers on the fracture toughness of the biomimicked composites.

scholarly journals STRINGS, NONCOMMUTATIVE GEOMETRY AND THE SIZE OF THE TARGET SPACE

1999 ◽  
Vol 14 (28) ◽  
pp. 4501-4517 ◽  
Author(s):  
FEDELE LIZZI
Keyword(s):  
String Theory ◽  
Dirac Operator ◽  
Noncommutative Geometry ◽  
Low Energy ◽  
Target Space ◽  
World Sheet ◽  
Crucial Point ◽  
Spectral Action ◽  
Energy Eigenvalues ◽  
The World

We describe how the presence of the antisymmetric tensor (torsion) on the world sheet action of string theory renders the size of the target space a gauge noninvariant quantity. This generalizes the R ↔ 1/R symmetry in which momenta and windings are exchanged, to the whole O(d,d,ℤ). The crucial point is that, with a transformation, it is possible always to have all of the lowest eigenvalues of the Hamiltonian to be momentum modes. We interpret this in the framework of noncommutative geometry, in which algebras take the place of point spaces, and of the spectral action principle for which the eigenvalues of the Dirac operator are the fundamental objects, out of which the theory is constructed. A quantum observer, in the presence of many low energy eigenvalues of the Dirac operator (and hence of the Hamiltonian) will always interpreted the target space of the string theory as effectively uncompactified.

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