scholarly journals Characterization of granite and limestone powders for use as fillers in bituminous mastics dosage

2014 ◽  
Vol 86 (2) ◽  
pp. 995-1002 ◽  
Author(s):  
BRENO BARRA ◽  
LETO MOMM ◽  
YADER GUERRERO ◽  
LIEDI BERNUCCI
Keyword(s):  
Laser Emission ◽  
Asphalt Binder ◽  
Chemical Analyses ◽  
Asphalt Mixes ◽  
X Ray ◽  
Active Behavior ◽  
Physical Hardening ◽  
Penetration Tests ◽  
Filler Activity

This paper discusses the importance of studies on materials known as fillers from different mineral origins, used in asphalt mixes, specifically in the formulation of mastics. The research was carried out on samples of limestone and granite rock filler and asphalt binder (50/70). The samples were evaluated through semiquantitative chemical analyses by X-ray fluorescence, granulometry by low angle laser emission, scanning electron microscopy, softening point tests, penetration tests, and aggregate-asphalt binder and aggregate-mastic adhesion tests. The results highlighted convergent trends, indicating that the active behavior of the fillers in the mastic formulation is not related to the size of the particles, but rather to their form, surface texture, specific surface area and mineralogical nature, allowing the filler activity concept to be divided into two components: physical (hardening) and chemical (adhesion).

Solid State Synthesis and Characterization of Spintronics Material Cd0.55 Hg0.45 Te

2010 ◽  
Vol 44-47 ◽  
pp. 2299-2306
Author(s):  
H.M.Noor Ul Huda Khan Asghar ◽  
M. Asghar ◽  
M.S. Awan
Keyword(s):  
Solid State ◽  
Synthesis And Characterization ◽  
Chemical Analyses ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
Cubic Crystal ◽  
X Ray ◽  
Edx Analyses ◽  
Scanning Electron

Polycrystalline spintronic material (Cd0.55Hg0.45Te) was synthesized by conventional solid state reaction. The samples ( = 5 mm and T = 1.5 mm) were prepared by uni-axial pressing. Samples were melted at 800°C for 3-2 hours. For chemical analyses, surface morphology and structural analyses, scanning electron microscopy (SEM) equipped with EDX system and X-ray diffraction studies were performed. XRD confirmed the cubic crystal structure. The Lattice constant of (Cd0.55Hg0.45Te) as determined by XRD was 0.6464 nm. The Miller indices (hkl) have been found by using crystallography method. The observed planes were (200), (210) and (331). The EDX analyses showed the typically compositions: Te 24.8% Cd 14.8% Al 5% and O2 46.4 % & C 9% (3 hours treatment) and Te 28.1% Cd 16% Al 4.1% and O2 39.3 %, Si 0.360% & C 12.1% (2 hours treatment) however we could not find any representative peak for Hg in all of the EDX analyses.

scholarly journals Thermochemical Properties of Hydrophilic Polymers from Cashew and Khaya Exudates and Their Implications on Drug Delivery

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Emmanuel O. Olorunsola ◽  
Partap G. Bhatia ◽  
Babajide A. Tytler ◽  
Michael U. Adikwu
Keyword(s):  
Hydrophilic Polymer ◽  
Thermochemical Properties ◽  
Chemical Analyses ◽  
X Ray Diffraction ◽  
Cashew Gum ◽  
X Ray ◽  
Acidic Drugs ◽  
Acacia Gum ◽  
Khaya Senegalensis

Characterization of a polymer is essential for determining its suitability for a particular purpose. Thermochemical properties of cashew gum (CSG) extracted from exudates of Anacardium occidentale L. and khaya gum (KYG) extracted from exudates of Khaya senegalensis were determined and compared with those of acacia gum BP (ACG). The polymers were subjected to different thermal and chemical analyses. Exudates of CSG contained higher amount of hydrophilic polymer. The pH of 2% w/v gum dispersions was in the order KYG < CSG < ACG. Calcium was the predominant ion in CSG while potassium was predominant in KYG. The FTIR spectra of CSG and KYG were similar and slightly different from that of ACG. Acacia and khaya gums exhibited the same thermal behaviour which is different from that of CSG. X-ray diffraction revealed that the three gums are the same type of polymer, the major difference being the concentration of metal ions. This work suggests the application of cashew gum for formulation of basic and oxidizable drugs while using khaya gum for acidic drugs.

scholarly journals Characterization of Philippine natural bentonite

2021 ◽  
Vol 2 ◽  
Author(s):  
Eleanor M. Olegario ◽  
Mon Bryan Z. Gili
Keyword(s):  
Cation Exchange Capacity ◽  
Ammonium Acetate ◽  
Exchange Capacity ◽  
Ftir Analysis ◽  
Chemical Analyses ◽  
Barium Acetate ◽  
Scanning Calorimetry ◽  
X Ray ◽  
The Common

Abstract Philippine natural bentonite is characterized using X-ray diffractometer (XRD), scanning electron microscope (SEM), chemical analysis, thermogravimetric-differential scanning calorimetry (TG-DSC), and Fourier transform infrared (FTIR) analysis. The cation exchange capacity (CEC) was also measured. XRD shows that the mineral is composed primarily of mordenite, hectorite, and montmorillonite. SEM shows the flaky and porous structure of the bentonite powder. Chemical analyses show that SiO2 (47.90 wt%) and Al2O3 (14.02 wt%) are the major components of the clay. TG-DSC shows that the mineral contains 15.55% moisture. IR transmittance spectrum shows the common vibration bands present in the sample which include O–H stretching of inter-porous water, symmetric and asymmetric stretching of hydroxyl functional groups, asymmetrical stretching of internal tetrahedra (O–Si–O and O–Al–O), symmetrical stretching of external linkages, and so on. The measured CEC were found to be 91.37 and 43.01 meq/100 g according to the ammonium acetate method and barium acetate method, respectively.

Characterization of two forms of sepiolite and related Mg-rich clay minerals from Yenidoğ an (Sivrihisar, Turkey)

Clay Minerals ◽  
2014 ◽  
Vol 49 (1) ◽  
pp. 91-108 ◽  
Author(s):  
M. Yeniyol
Keyword(s):  
Field Work ◽  
Ion Concentration ◽  
Morphological Properties ◽  
Chemical Analyses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Direct Precipitation ◽  
Extensive Field ◽  
Sedimentary Succession

AbstractAn Early Pliocene sedimentary succession in the Yenidoğan area, Sivrihisar, Turkey, consists of sepiolite, stevensite, kerolite, dolomite and magnesite. The geology, mineralogy and geochemistry of the succession was examined by extensive field work along several trenches and a representative measured section, followed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermal, and chemical analyses.Structurally, two distinct forms of sepiolites were distinguished by XRD: (a) well crystallized sepiolite with a 110 reflection at 12.07–12.3 Å , and (b) poorly crystallized sepiolite in which the 110 reflection occurs at 12.7–13.0 Å (denoted as sepiolite-13Å ). Differences in crystal chemistry, thermal and morphological properties of these forms, the vibrational spectra and XRD characterization of the related phyllosilicates were also documented.Stevensite, kerolite and sepiolite were formed by direct precipitation from alkaline lake water rich in Mg and Si. Sepiolite-13Å was probably formed by transformation from precursor smectite via dissolution-precipitation, more likely during early diagenesis. Environmental conditions such as ion concentration, salinity and variations in pH may have controlled the formation of the phyllosilicates.

Characterization of Air Void Distribution in Asphalt Mixes using X-ray Computed Tomography

2002 ◽  
Vol 14 (2) ◽  
pp. 122-129 ◽  
Author(s):  
E. Masad ◽  
V. K. Jandhyala ◽  
N. Dasgupta ◽  
N. Somadevan ◽  
N. Shashidhar
Keyword(s):  
Computed Tomography ◽  
Asphalt Mixes ◽  
X Ray ◽  
Void Distribution ◽  
X Ray Computed ◽  
Air Void

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

Digital x-ray mapping of nanometer-size supported bimetallic catalysts

1988 ◽  
Vol 46 ◽  
pp. 530-531
Author(s):  
L. T. Germinario
Keyword(s):  
Background Radiation ◽  
Metal Cluster ◽  
Single Element ◽  
Beam Diameter ◽  
X Rays ◽  
X Ray ◽  
Major Interest ◽  
Induced Changes

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.

Plant Pathology Diagnosed by X-Ray Microanalysis

1987 ◽  
Vol 45 ◽  
pp. 974-975
Author(s):  
J. H. Resau ◽  
N. Howell ◽  
S. H. Chang
Keyword(s):  
Electron Microscopy ◽  
Plant Pathology ◽  
Biochemical Characterization ◽  
Nutrient Deficiency ◽  
Green Leaf ◽  
Parasitic Infestation ◽  
X Ray

Spinach grown in Texas developed “yellow spotting” on the peripheral portions of the leaves. The exact cause of the discoloration could not be determined as there was no evidence of viral or parasitic infestation of the plants and biochemical characterization of the plants did not indicate any significant differences between the yellow and green leaf portions of the spinach. The present study was undertaken using electron microscopy (EM) to determine if a micro-nutrient deficiency was the cause for the discoloration.Green leaf spinach was collected from the field and sent by express mail to the EM laboratory. The yellow and equivalent green portions of the leaves were isolated and dried in a Denton evaporator at 10-5 Torr for 24 hrs. The leaf specimens were then examined using a JEOL 100 CX analytical microscope. TEM specimens were prepared according to the methods of Trump et al.

EXELFS Studies of Carbon Fibers

1990 ◽  
Vol 48 (2) ◽  
pp. 72-73
Author(s):  
V. Serin ◽  
K. Hssein ◽  
G. Zanchi ◽  
J. Sévely
Keyword(s):  
Carbon Fibers ◽  
Energy Analysis ◽  
Electron Excitation ◽  
Complex Structures ◽  
High Modulus ◽  
Promising Technique ◽  
X Ray ◽  
Fine Structures ◽  
X Ray Absorption

The present developments of electron energy analysis in the microscopes by E.E.L.S. allow an accurate recording of the spectra and of their different complex structures associated with the inner shell electron excitation by the incident electrons (1). Among these structures, the Extended Energy Loss Fine Structures (EXELFS) are of particular interest. They are equivalent to the well known EXAFS oscillations in X-ray absorption spectroscopy. Due to the EELS characteristic, the Fourier analysis of EXELFS oscillations appears as a promising technique for the characterization of composite materials, the major constituents of which are low Z elements. Using EXELFS, we have developed a microstructural study of carbon fibers. This analysis concerns the carbon K edge, which appears in the spectra at 285 eV. The purpose of the paper is to compare the local short range order, determined by this way in the case of Courtauld HTS and P100 ex-polyacrylonitrile carbon fibers, which are high tensile strength (HTS) and high modulus (HM) fibers respectively.

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