scholarly journals REGULARITIES OF THE PROCESSES OF FORMATION OF THE STRUCTURE AND STRENGTH OF A CLINKER-FREE BINDER OF ALKALINE ACTIVATION

2020 ◽  
Vol 3 (1) ◽  
pp. 21-29 ◽  
Author(s):  
M. Nahaev ◽  
M. Salamanova ◽  
Z. Ismailova
Keyword(s):  
Construction Industry ◽  
Electron Probe ◽  
Cement Stone ◽  
Optimal Composition ◽  
Magmatic Origin ◽  
Alkaline Activation ◽  
X Ray ◽  
Fine Powders ◽  
Amorphous Compounds ◽  
Energy Consuming

resource- and energy-consuming Portland cement is currently considered the most popular material in the construction industry, but its production can be attributed to the category of harmful industries in terms of the amount of emissions into the environment. Therefore, the development of a clinker-free technology for the production of binders based on mineral fine powders of aluminosilicate nature activated by an alkaline coater is a relevant and promising direction. In the work, the laws of the processes occurring during the structure formation of clinker-free binder systems of alkaline activation on alkaline cements using blast furnace granulated slags in a finely dispersed state are studied. Formulations are given and the properties of clinker-free binders of alkaline activation on mineral fine powders from rocks of sedimentary and magmatic origin are investigated. Electron probe studies and X-ray phase analysis revealed the presence of hydrated amorphous compounds close in composition to zeolites in cement stone. An analysis of the results allowed us to determine the optimal composition of clinker-free binder alkaline activation “silicified marl + volcanic tuff (70: 30%) + Na2Si03 + Na0H” with activity ranging from 42.0 - 54.5 MPa, depending on the conditions of hardening of the samples.

scholarly journals FEATURES OF THE STRUCTURE FORMATION OF MULTICOMPONENT BINDING SYSTEMS OF ALKALINE ACTIVATION

2020 ◽  
pp. 51-58
Author(s):  
С-А. Ю. Муртазаев ◽  
М. Ш. Саламанова ◽  
Д. К-С. Батаев
Keyword(s):  
Portland Cement ◽  
Construction Industry ◽  
Practical Importance ◽  
Cement Stone ◽  
Reinforced Concrete Structures ◽  
Alkaline Activation ◽  
Fine Powders ◽  
Natural Aluminosilicate ◽  
Alkaline Activator ◽  
Theoretical Foundations

Разработка рецептур бесклинкерных вяжущих связок щелочной активации на основе тонкодисперсных порошков природного алюмосиликатного происхождения позволит получать новые эффективные строительные композиты. В работе раскрываются вопросы, связанные с теоретическими основами формирования структуры и прочности цементного камня на основе щелочного активатора. Результаты исследований, на наш взгляд, безусловно представляют практическую значимость для строительной отрасли, так как предлагаемые рецептуры бесклинкерных цементов способны заменить дорогой и энергоемкий портландцемент, позволяя создавать прочные и долговечные бетонные и железобетонные конструкции. The development of formulations of clinker-free binders of alkaline activation based on fine powders of natural aluminosilicate origin will make it possible to obtain new effective building composites. The paper reveals issues related to the theoretical foundations of the formation of the structure and strength of cement stone based on an alkaline activator. The research results, in our opinion, undoubtedly are of practical importance for the construction industry, since the proposed recipes for clinker-free cements can replace expensive and energy-intensive Portland cement, allowing you to create strong and durable concrete and reinforced concrete structures.

scholarly journals Agro Waste Sugarcane Bagasse as a Cementitious Material for Reactive Powder Concrete

2020 ◽  
Vol 2 (4) ◽  
pp. 476-491
Author(s):  
Selvadurai Sebastin ◽  
Arun Kumar Priya ◽  
Alagar Karthick ◽  
Ravishankar Sathyamurthy ◽  
Aritra Ghosh
Keyword(s):  
Construction Industry ◽  
Reactive Powder Concrete ◽  
Manufacturing Cost ◽  
Quartz Powder ◽  
X Ray ◽  
Fine Powders ◽  
Different Temperatures ◽  
Reactive Powder ◽  
Concrete Science ◽  
Very High

In the field of advanced concrete science, the construction industry has risen to great heights. Due to its own characterisation, the manufacturing cost of reactive powder concrete (RPC) is very high. This can be minimised by substituting the components of the RPC with the aid of agro waste. Because of the production of sugar from the sugar cane industry, bagasse ash is abundantly available in India. It is not ideal for the direct replacement of ingredients in concrete because of the presence of carbon dioxide in bagasse ash. The study of bagasse ash’s actions under different temperatures and different exposure times is discussed in this paper. It is inferred from the findings obtained from the energy dispersive study of X-ray (EDAX) that the presence of reactive silica in bagasse ash could be substituted by RPC ingredients due to heat treatment. RPC is composed of exceptionally fine powders (cement, sand, quartz powder and silica smolder) and superplasticiser. The superplasticiser, utilised at its ideal dose, decreases the water to cement proportion (w/c) while enhancing the workability of the concrete. A thick matrix is accomplished by optimising the granular packing of the dry fine powders. This compactness gives RPC ultra-high quality and durability. Reactive powder concretes have compressive qualities extending from 200 to 800 MPa.

RESEARCH OF PROPERTIES OF MULTI-COMPONENT FILLED ALKALINE ACTIVATION KNITTING SYSTEMS

2021 ◽  
Vol 93 (1) ◽  
pp. 114-124
Author(s):  
S-A. YU. MURTAZAEV ◽  
◽  
M. SH. SALAMANOVA ◽  
◽  
Keyword(s):  
Construction Industry ◽  
Building Materials ◽  
Raw Materials ◽  
Practical Importance ◽  
Cement Stone ◽  
Resource Potential ◽  
Alkaline Activation ◽  
Technological Processing ◽  
Alkaline Activator ◽  
Theoretical Foundations

The anthropogenic load on the planet’s natural resource potential is growing rapidly, therefore, special attention is paid to the development of less costly and low energy-intensive technologies for obtaining new building materials, the implementation of which does not require high-temperature and expensive technological processing, and will allow the use of local secondary and substandard raw materials. The development of formulations of clinker-free binders of alkaline activation based on fine powders of natural and technogenic origin will allow to obtain new effective building composites. The paper reveals issues related to the theoretical foundations of the formation of the structure and strength of cement stone based on an alkaline activator. The research results, in our opinion, undoubtedly are of practical importance for the construction industry, since the proposed recipes for clinker-free cements can replace expensive and energy-intensive Portland cement, allowing you to create strong and durable concrete and reinforced concrete structures.

Improvements in the electron probe forming capabilities and x-ray hole counts in the Philips TEM

1983 ◽  
Vol 41 ◽  
pp. 376-377
Author(s):  
Richard L. McConville
Keyword(s):  
Field Strength ◽  
Electron Probe ◽  
Spherical Aberration ◽  
Focal Length ◽  
Objective Lens ◽  
Parallel Beam ◽  
Tilt Axis ◽  
X Ray ◽  
Small Probe ◽  
Specimen Height

A second generation twin lens has been developed. This symmetrical lens with a wider bore, yet superior values of chromatic and spherical aberration for a given focal length, retains both eucentric ± 60° tilt movement and 20°x ray detector take-off angle at 90° to the tilt axis. Adjust able tilt axis height, as well as specimen height, now ensures almost invariant objective lens strengths for both TEM (parallel beam conditions) and STEM or nano probe (focused small probe) modes.These modes are selected through use of an auxiliary lens situ ated above the objective. When this lens is on the specimen is illuminated with a parallel beam of electrons, and when it is off the specimen is illuminated with a focused probe of dimensions governed by the excitation of the condenser 1 lens. Thus TEM/STEM operation is controlled by a lens which is independent of the objective lens field strength.

Spatial resolution of X-ray microanalysis in thin foils

1978 ◽  
Vol 36 (1) ◽  
pp. 544-545
Author(s):  
R. Hutchings ◽  
I.P. Jones ◽  
M.H. Loretto ◽  
R.E. Smallman
Keyword(s):  
Spatial Resolution ◽  
Electron Probe ◽  
Beam Divergence ◽  
Inelastic Interaction ◽  
Specimen Thickness ◽  
High Current ◽  
Beam Spreading ◽  
X Ray ◽  
Thin Foils ◽  
Complex Calculation

There is increasing interest in X-ray microanalysis of thin specimens and the present paper attempts to define some of the factors which govern the spatial resolution of this type of microanalysis. One of these factors is the spreading of the electron probe as it is transmitted through the specimen. There will always be some beam-spreading with small electron probes, because of the inevitable beam divergence associated with small, high current probes; a lower limit to the spatial resolution is thus 2αst where 2αs is the beam divergence and t the specimen thickness.In addition there will of course be beam spreading caused by elastic and inelastic interaction between the electron beam and the specimen. The angle through which electrons are scattered by the various scattering processes can vary from zero to 180° and it is clearly a very complex calculation to determine the effective size of the beam as it propagates through the specimen.

High spatial resolution x-ray microanalysis of interfaces

1995 ◽  
Vol 53 ◽  
pp. 284-285
Author(s):  
J. R. Michael
Keyword(s):  
Spatial Resolution ◽  
Electron Probe ◽  
Solid Angle ◽  
Collection Efficiency ◽  
Spatial Scales ◽  
Energy Dispersive Spectrometer ◽  
X Rays ◽  
X Ray ◽  
Probe Size ◽  
Brightness Field

X-ray microanalysis in the analytical electron microscope (AEM) refers to a technique by which chemical composition can be determined on spatial scales of less than 10 nm. There are many factors that influence the quality of x-ray microanalysis. The minimum probe size with sufficient current for microanalysis that can be generated determines the ultimate spatial resolution of each individual microanalysis. However, it is also necessary to collect efficiently the x-rays generated. Modern high brightness field emission gun equipped AEMs can now generate probes that are less than 1 nm in diameter with high probe currents. Improving the x-ray collection solid angle of the solid state energy dispersive spectrometer (EDS) results in more efficient collection of x-ray generated by the interaction of the electron probe with the specimen, thus reducing the minimum detectability limit. The combination of decreased interaction volume due to smaller electron probe size and the increased collection efficiency due to larger solid angle of x-ray collection should enhance our ability to study interfacial segregation.

Microchemical imaging in biomedical research

1992 ◽  
Vol 50 (2) ◽  
pp. 1118-1119
Author(s):  
P. Ingram
Keyword(s):  
Data Analysis ◽  
Electron Probe ◽  
The Other ◽  
X Ray ◽  
Cell Element ◽  
Physiological Information ◽  
Functional States ◽  
Elemental Maps ◽  
Electron Energy Loss ◽  
Secondary Ion

It is well established that unique physiological information can be obtained by rapidly freezing cells in various functional states and analyzing the cell element content and distribution by electron probe x-ray microanalysis. (The other techniques of microanalysis that are amenable to imaging, such as electron energy loss spectroscopy, secondary ion mass spectroscopy, particle induced x-ray emission etc., are not addressed in this tutorial.) However, the usual processes of data acquisition are labor intensive and lengthy, requiring that x-ray counts be collected from individually selected regions of each cell in question and that data analysis be performed subsequent to data collection. A judicious combination of quantitative elemental maps and static raster probes adds not only an additional overall perception of what is occurring during a particular biological manipulation or event, but substantially increases data productivity. Recent advances in microcomputer instrumentation and software have made readily feasible the acquisition and processing of digital quantitative x-ray maps of one to several cells.

Reduction of Potassium in Kidney Proximal Tubules to Aid in Electron Probe X-Ray Microanalysis of Calcium

1985 ◽  
Vol 43 ◽  
pp. 474-475
Author(s):  
A. LeFurgey ◽  
P. Ingram ◽  
L.J. Mandel
Keyword(s):  
Smooth Muscle ◽  
Proximal Tubule ◽  
Electron Probe ◽  
Clinical Applications ◽  
Proximal Tubules ◽  
Rabbit Kidney ◽  
Target Cells ◽  
X Ray ◽  
Freeze Dried

For quantitative determination of subcellular Ca distribution by electron probe x-ray microanalysis, decreasing (and/or eliminating) the K content of the cell maximizes the ability to accurately separate the overlapping K Kß and Ca Kα peaks in the x-ray spectra. For example, rubidium has been effectively substituted for potassium in smooth muscle cells, thus giving an improvement in calcium measurements. Ouabain, a cardiac glycoside widely used in experimental and clinical applications, inhibits Na-K ATPase at the cell membrane and thus alters the cytoplasmic ion (Na,K) content of target cells. In epithelial cells primarily involved in active transport, such as the proximal tubule of the rabbit kidney, ouabain rapidly (t1/2= 2 mins) causes a decrease2 in intracellular K, but does not change intracellular total or free Ca for up to 30 mins. In the present study we have taken advantage of this effect of ouabain to determine the mitochondrial and cytoplasmic Ca content in freeze-dried cryosections of kidney proximal tubule by electron probe x-ray microanalysis.

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