scholarly journals New Deposit of Mordenite–Clinoptilolite in the Eastern Region of Cuba: Uses as Pozzolans

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4676
Author(s):  
Jorge Luis Costafreda ◽  
Domingo Alfonso Martín
Keyword(s):  
Effective Properties ◽  
Volcanic Glass ◽  
Heat Of Hydration ◽  
Quality Analysis ◽  
Insoluble Residue ◽  
Eastern Region ◽  
Secondary Phases ◽  
X Ray ◽  
Industrial Manufacturing ◽  
Hydration Resistance

This work describes the newly discovered zeolites in the eastern region of Cuba. In the researched area, there have been no previous studies of natural zeolite exploration. Therefore, the results shown here are new. The main object of this research is to analyse five samples of zeolites and demonstrate their pozzolanic capacity and the possibility of their usage in the industrial manufacturing of pozzolanic cements. The study of the samples was performed by X-ray diffraction (XRD), X-ray fluorescence (XRF) and scanning electron microscopy (SEM). A chemical analysis (CAQ) to determine the quality of the samples as pozzolans was performed, by determining the total SiO2, reactive SiO2, total CaO, reactive CaO, Al2O3, MgO and the insoluble residue (I.R.). Lastly, an eight-day pozzolanicity analysis (PA) was carried out to determine the pozzolanic reactivity of the samples. The results obtained by XRD, XRF and SEM established that the researched zeolite samples have two main zeolitic phases: mordenite and clinoptilolite. Altered volcanic glass, quartz and smectite (montmorillonite) are the secondary phases. The results of the chemical quality analysis (CAQ) showed that the samples contain a considerable amount of reactive SiO2 and reactive CaO, as well as a low content of insoluble residue, which reinforces their properties as pozzolans. The results of the pozzolanicity analysis (PA) concluded that the analysed samples actively react with Ca(OH)2 after eight days. Based on all the results mentioned above, it is established that both mordenite and clinoptilolite behave like pozzolans and can be recommended for the manufacture of pozzolanic cements, which have more effective properties than Portland cement, in terms of physical, chemical and mechanical strength, low heat of hydration, resistance to sulphates, low CO2 emissions to the atmosphere and negligible impacts on the environment.

Image Quality Analysis of X-ray Grating Interferometer Using Integrating-bucket Method

2020 ◽  
Vol 64 (2) ◽  
pp. 20503-1-20503-5
Author(s):  
Faiz Wali ◽  
Shenghao Wang ◽  
Ji Li ◽  
Jianheng Huang ◽  
Yaohu Lei ◽  
...  
Keyword(s):  
Image Quality ◽  
Phase Contrast ◽  
Quality Analysis ◽  
Phase Contrast Imaging ◽  
Phase Image ◽  
Contrast Imaging ◽  
High Quality ◽  
Image Quality Analysis ◽  
X Ray ◽  
Grating Interferometer

Abstract Grating-based x-ray phase-contrast imaging has the potential to enhance image quality and provide inner structure details non-destructively. In this work, using grating-based x-ray phase-contrast imaging system and employing integrating-bucket method, the quantitative expressions of signal-to-noise ratios due to photon statistics and mechanical error are analyzed in detail. Photon statistical noise and mechanical error are the main sources affecting the image noise in x-ray grating interferometry. Integrating-bucket method is a new phase extraction method translated to x-ray grating interferometry; hence, its image quality analysis would be of great importance to get high-quality phase image. The authors’ conclusions provide an alternate method to get high-quality refraction signal using grating interferometer, and hence increases applicability of grating interferometry in preclinical and clinical usage.

scholarly journals Aluminium Alloy Foam Modelling and Prediction of Elastic Properties Using X-ray Microcomputed Tomography

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 925
Author(s):  
Diogo Heitor ◽  
Isabel Duarte ◽  
João Dias-de-Oliveira
Keyword(s):  
Aluminium Alloy ◽  
Finite Element Modelling ◽  
Effective Properties ◽  
Numerical Models ◽  
Microcomputed Tomography ◽  
Cellular Materials ◽  
Metallic Foams ◽  
X Ray ◽  
The Impact ◽  
Structural Imperfections

X-ray microcomputed tomography has been gaining relevance in the field of cellular materials to characterize materials and analyse their microstructure. So, here, it was used together with finite element modelling to develop numerical models to estimate the effective properties (Young’s modulus) of aluminium alloy foams and evaluate the effects of processing on the results. A manual global thresholding technique using the mass as a quality indicator was used. The models were reconstructed (Marching Cubes 33), then simplified and analysed in terms of mass and shape maintenance (Hausdorff distance algorithm) and face quality. Two simplification procedures were evaluated, with and without small structural imperfections, to evaluate the impact of the procedures on the results. Results demonstrate that the developed procedures are good at minimizing changes in mass and shape of the geometries while providing good face quality, i.e., face aspect ratio. The models are also shown to be able to predict the effective properties of metallic foams in accordance with the findings of other researchers. In addition, the process of obtaining the models and the presence of small structural imperfections were shown to have a great impact on the results.

TEM and X-Ray Examinations of Intermetallic Phases and Carbides Precipitation in an Fe-Ni Superalloy during Prolonged Ageing

2013 ◽  
Vol 212 ◽  
pp. 15-20
Author(s):  
Kazimierz J. Ducki ◽  
Jacek Mendala ◽  
Lilianna Wojtynek
Keyword(s):  
Heat Treatment ◽  
Solution Heat Treatment ◽  
Intermetallic Phase ◽  
Intermetallic Phases ◽  
Precipitation Process ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Solid Samples ◽  
Structural Investigations ◽  
X Ray

The influence of prolonged ageing on the precipitation process of the secondary phases in an Fe-Ni superalloy of A-286 type has been studied. The samples were subjected to a solution heat treatment at 980°C for 2 h and water quenched, and then aged at temperatures of 715, 750 and 780°C at holding times from 0.5 to 500 h. Structural investigations were conducted using TEM and X-ray diffraction methods. The X-ray phase analyses performed on the isolates were obtained by anodic dissolution of the solid samples. After solution heat treatment the alloy has the structure of twinned austenite with a small amount of undissolved precipitates, such as carbide TiC, carbonitride TiC0.3N0.7, nitride TiN0.3, carbosulfide Ti4C2S2, Laves phase Ni2Si, and boride MoB. The application of ageing causes precipitation processes of γ-Ni3(Al,Ti), G (Ni16Ti6Si7), η (Ni3Ti), β (NiTi) and σ (Cr0.46Mo0.40Si0.14) intermetallic phases, as well as the carbide M23C6. It was found that the main phase precipitating during alloy ageing was the γ intermetallic phase.

Quantifying the influence of secondary phases on corrosion in multicomponent Mg alloys using X-ray computed microtomography

2021 ◽  
pp. 110010
Author(s):  
Chi Zhang ◽  
Chen Liu ◽  
Xin Li ◽  
Keli Liu ◽  
Guangyuan Tian ◽  
...  
Keyword(s):  
Mg Alloys ◽  
Secondary Phases ◽  
X Ray ◽  
Computed Microtomography ◽  
X Ray Computed

Depth Profile of Structure, Strain, and Composition in an Annealed Al-Cu-Fe-Cr Quasicrystalline Film

2001 ◽  
Vol 695 ◽  
Author(s):  
M.J. Daniels ◽  
D. King ◽  
J.S. Zabinski ◽  
Z.U. Rek ◽  
J.C. Bilello
Keyword(s):  
Residual Strain ◽  
Incident Angle ◽  
Rf Sputtering ◽  
Strain Analysis ◽  
Grazing Incidence ◽  
Grain Structure ◽  
Second Phase ◽  
Secondary Phases ◽  
Composite Target ◽  
X Ray

ABSTRACTQuasicrystalline films were formed by RF sputtering from a powder composite target onto Inconel substrates, which produces a polymorphic nanoquasicrystalline grain structure, ~2.5 - 10 nm. Subsequent annealing at 500°C for 4 hours, at base pressures of below 5*10-5 Torr, and with Ar flow to 5 - 10 mT, fully develops the quasicrystalline structure with decagonal phase predominating, except near the termination surface. Analysis by XPS indicated extensive oxygen incorporation and limited aluminum enrichment at the termination surface. These results are correlated with structure and strain analysis via synchrotron grazing incidence x-ray scattering (GIXS). By varying the incident angle, hence the x-ray penetration depth, the evolution of an amorphous and crystalline crystalline secondary phases at the surface of the film has been detected. Residual strain analysis shows that this second phase induces a compressive residual strain of 0.10% as measured from the displacement of the major quasicrystalline peaks in the surface layers of the film.

The Chromatography of Rubber Solutions

1939 ◽  
Vol 12 (4) ◽  
pp. 762-773 ◽  
Author(s):  
Giampietro Cajelli
Keyword(s):  
Elastic Properties ◽  
Potassium Hydroxide ◽  
The Other ◽  
Precipitation Method ◽  
Insoluble Residue ◽  
Fractional Precipitation ◽  
Micellar Structure ◽  
X Ray ◽  
Colored Product ◽  
Considerable Doubt

Abstract In the opinion of Pummerer, there is considerable doubt about the homogeneity of the fractions obtained by fractional precipitation of rubber from dilute benzene solutions, both with respect to the size of the molecules and to the state of aggregation. Based on the results of x-ray measurements of fibrous substances, to which type stretched rubber belongs, Meyer and Mark have advanced the hypothesis of the existence of chains of primary valences and of a micellar structure. PURIFICATION OF RUBBER There are four important and at the same time essentially different ways of carrying out the difficult process of purifying rubber. According to Harries, acetone extraction gives a colored product and leads to profound changes in the elastic properties. Staudinger adopted the method described by Wildmann in 1911, which involves the use of a mixture of acetone and chloroform. On the other hand, Pummerer and Koch used the method of fractional precipitation; the rubber after severe mastication was extracted with acetone, was dissolved in benzene, the liquid was allowed to stand for several weeks, the solution was decanted from the insoluble residue and was fractionally precipitated by alcohol and acetone. More recently this same method has been perfected by Pummerer and Meidel, and by this means a fraction of crystallized rubber was isolated from the mother liquors of the fractional precipitation. Finally Pummerer and Koch have purified rubber by treatment with an alkali, combining the precipitation method with the use of a solution of potassium hydroxide in methanol. Later this method was modified by Pummerer and Pahl. The use of latex in place of crude rubber is the most important development in obtaining a satisfactory product. De Vries and Beumée-Nieuwland have described in detail some results obtained with fresh latex. The total-rubber obtained by the methods just described contains, according to the quality and the age of the sample of latex, from 0.1 to 0.4 per cent of nitrogen which cannot be removed by washing, even when this is exhaustive.

Synthesis and Characterization of Brannerite Compositions for MOX Residue Disposal

MRS Advances ◽  
2016 ◽  
Vol 2 (10) ◽  
pp. 557-562 ◽  
Author(s):  
D.J. Bailey ◽  
M.C. Stennett ◽  
N.C. Hyatt
Keyword(s):  
Powder Diffraction ◽  
Microstructural Analysis ◽  
Charge Compensation ◽  
Phase Assemblage ◽  
Secondary Phases ◽  
Host Matrix ◽  
Neutron Absorber ◽  
X Ray ◽  
Valence States ◽  
Trivalent Cations

ABSTRACTDue to their high actinide content MOX residues require immobilization within a robust host matrix. Although it is possible to immobilize actinides in vitreous wasteforms; ceramic phases, such as brannerite (UTi2O6), are attractive due to their high waste loading capacity and relative insolubility. Brannerites Gd0.1U0.9Ti2O6, Ce0.1U0.9Ti2O6and Gd0.1U0.81Ce0.09Ti2O6were prepared using an oxide route. Charge compensation of trivalent cations was expected to occur via the oxidation of U (IV) to higher valence states (U (V) or U (VI)). Gd was added to act as a neutron absorber in the final Pu bearing wasteform and Ce was used as a structural surrogate for Pu. X-ray absorption spectroscopy showed that Ce (IV) was reduced to Ce (III) in all cases. X-ray powder diffraction of synthesized specimens found that the final phase assemblage was strongly affected by processing atmosphere (air or argon). Prototypical brannerite was formed in all compositions, secondary phases observed were found to vary according to processing atmosphere and stoichiometry. Microstructural analysis (SEM) of the sintered samples confirmed the results of the X-ray powder diffraction.

scholarly journals OPTIMIZATION OF THE USE OF FLY ASH AS AN ADDITIVE PORTLAND COMPOSITE CEMENT (PCC)

2019 ◽  
Vol 4 (2) ◽  
pp. 61-72 ◽  
Author(s):  
Leni Rumiyanti ◽  
Listiani Listiani ◽  
Tika Damayanti
Keyword(s):  
Fly Ash ◽  
Setting Time ◽  
Quality Analysis ◽  
Insoluble Residue ◽  
Optimum Conditions ◽  
Free Lime ◽  
Composite Cement ◽  
Ideal Composition ◽  
Physical And Chemical ◽  
The Ideal

Research has been carried out on the optimization of the use of Lahat Fly Ash as an Additive Portland Composite Cement (PCC) which aims to determine the optimum conditions for adding Lahat fly ash to produce cement with physical and chemical requirements in accordance with SNI 7064:2014 and discover the ideal composition of cement with fly additions Lahat ash from various cement compositions. The quality analysis in making PCC cement is chemically in the form of Insoluble Residue (IR), Loss of Ignition (LOI), and free lime (FCaO) as well as the quality of physics in the form of Blaine, setting time, and cement mortar compressive strength. The results obtained after the process of making PCC cement with the addition of 14% Lahat fly ash, namely PCC cement in optimum conditions with physical and chemical requirements in accordance with SNI 7064: 2014 where the ideal composition of PCC cement manufacture is 14% Lahat fly ash, clinker 62%, 3% gypsum, 18% limestone, and 3% pozzolans in making PCC cement. Therefore, Lahat fly ash can be used as an alternative mixture in making PCC cement.

scholarly journals Znx-1CuxMn2O4 Spinels; Synthesis, Structural Characterization and Electrical Evaluation

2019 ◽  
Vol 54 (1) ◽  
Author(s):  
Francisco Méndez-Martínez ◽  
Federico González ◽  
Enrique Lima ◽  
Pedro Bosch ◽  
Heriberto Pfeiffer
Keyword(s):  
Impedance Spectroscopy ◽  
Structural Characterization ◽  
Morphological Changes ◽  
Secondary Phases ◽  
Varistor Ceramic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Copper Addition ◽  
Partial Inverse ◽  
Scanning Electron

This work presents the structural characterization and electrical evaluation of Znx-1CuxMn2O4 spinels, which are materials presented as secondary phases into the varistor ceramic systems. Samples were analyzed by X-ray diffraction, solid-state nuclear magnetic resonance, infrared spectroscopy, scanning electron microscopy and impedance spectroscopy. Although, the addition of copper to the ZnMn2O4 spinel did not produce morphological changes, the structure and electrical behaviors changed considerably. Structurally, copper addition induced the formation of partial inverse spinels, and its addition increases significantly the electrical conductivity. Therefore, the formation of Znx-1CuxMn2O4 spinels, as secondary phases into the varistor materials, may compromise significantly the varistor efficiency.   Ceramic, Impedance Spectroscopy, spinel, Varistor, XRD.

Raman and X-ray Photoemission Identification of Colloidal Metal Sulfides as Potential Secondary Phases in Nanocrystalline Cu2ZnSnS4 Photovoltaic Absorbers

2020 ◽  
Vol 3 (6) ◽  
pp. 5706-5717
Author(s):  
Oleksandr Selyshchev ◽  
Yevhenii Havryliuk ◽  
Mykhailo Ya. Valakh ◽  
Volodymyr O. Yukhymchuk ◽  
Oleksandra Raievska ◽  
...  
Keyword(s):  
Metal Sulfides ◽  
Secondary Phases ◽  
X Ray ◽  
Colloidal Metal
Sign in / Sign up

Export Citation Format

Share Document