scholarly journals Petrographic and Mechanical Analyses of Selected Granitic Rock Deposits in Ado-Ekiti, South-West Nigeria.

2021 ◽  
Author(s):  
Olajide Tunmilayo Sanya ◽  
Braimoh Olanrewaju Jimoh ◽  
Boluwatife Olayide Dada ◽  
Olushola Bamidele Nenuwa ◽  
Israel Oluwaseun Taiwo
Keyword(s):  
Physical Properties ◽  
Granitic Rock ◽  
Strain Curve ◽  
Xrd Analysis ◽  
Granitic Rocks ◽  
X Ray Diffraction ◽  
Stress Strain Curve ◽  
Rock Samples ◽  
Petrographic Examination ◽  
Initial Fracture

Abstract In this study, the petrographic and mineralogy of selected granitic rocks on their physical and mechanical strength were evaluated. Granitic rock samples sourced from seven locations were analyzed to investigate their mineral micro-texture and compositions using petrographic examination and X-ray diffraction (XRD) analysis respectively. Mechanical properties including compressive strength and hardness of the examined rocks were performed following ASTM D7012–10 and EN 1534 standards. Their physical properties in term of specific gravity, porosity and water absorption were examined following ASTM C97/C97M. Results show that the predominant minerals in rock samples are quartz and kaolinite. Stress-strain curve displays plastic fragmentation after initial fracture in most granitic rock samples with rock samples from Olorunda Zone 9 and Olorunda Zone 2 exhibiting superior plastic deformation over a wide strain elongation. Their physical properties were within the acceptable range for construction applications.

The Effect of CaCO3 Addition on Physical Properties of ZnO-Based Crystal Glaze

2012 ◽  
Vol 620 ◽  
pp. 12-16 ◽  
Author(s):  
Abdul Rashid Jamaludin ◽  
Shah Rizal Kasim ◽  
Zainal Arifin Ahmad
Keyword(s):  
Electron Microscope ◽  
Calcium Carbonate ◽  
Scanning Electron Microscope ◽  
Physical Properties ◽  
Crystallization Temperature ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

The effects of calcium carbonate (CaCO3) addition on the physical properties of ZnO-based crystal glaze batches were investigated. Samples were fired at different gloss firing temperatures ranging from 1180-1220°C with 3 hours soaking at 1060°C crystallization temperature. X-ray diffraction (XRD) analysis identifiedthe crystal phase occurred as willemite (Zn2SiO4) and the scanning electron microscope (SEM) analysis indicated that willemite crystals are in the acicular needle like shape that formed spherulite. The intensities of willemite peaks decreased with CaCO3 addition and completely vanished at 5.0 wt% CaCO3. Varied formation of spherulites developed of the surface of crystal glaze as the flows of the glaze stretched further as the amount of CaCO3 increased.

The Structure of Rubber and the Mechanism of Elastic Stretching

1935 ◽  
Vol 8 (2) ◽  
pp. 192-209
Author(s):  
Edward Mack
Keyword(s):  
Strain Curve ◽  
Point Of View ◽  
Unified Theory ◽  
X Ray Diffraction ◽  
Stress Strain Curve ◽  
Joule Effect ◽  
Strict Adherence ◽  
Heat Effects ◽  
Cis And Trans ◽  
Trans Addition

Abstract A theory of the mechanism of elastic stretch in rubber is described. It is christened a “hydrogen-evaporation-condensation” mechanism. In an attempt to develop a unified theory of rubber behavior, some of the more important properties of the various forms of rubber are discussed, from the point of view of strict adherence to the principles of geometry and of structural organic chemistry. Among the topics discussed are: shape of the rubber molecule, the work of stretching rubber, the shape of the stress-strain curve, heat effects in rubber (including the Joule effect), Staudinger's hydrogenated rubber, factors controlling cis and trans addition, x-ray diffraction pattern, properties of synthetic rubbers, inversion, and sluggishness.

Phase Evolution and Physical Properties of (1-x)BZT-xBFN Ceramic System

2008 ◽  
Vol 55-57 ◽  
pp. 53-56 ◽  
Author(s):  
H. Maimon ◽  
Sukum Eitssayeam ◽  
Uraiwan Intatha ◽  
Tawee Tunkasiri ◽  
G. Satittada
Keyword(s):  
Physical Properties ◽  
Physical And Mechanical Properties ◽  
Phase Evolution ◽  
Xrd Analysis ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Ceramic System ◽  
Solid State Reaction Technique ◽  
Temperature Changes ◽  
X Ray

Phase evolution and physical properties of (1-x)BZT–xBFN ceramic system were investigated to find the optimum condition for electronic applications. (1-x)BZT–xBFN powders were prepared by solid state reaction technique varying x from 0.2 to 0.8 and various sintering temperatures from 1350 °C to 1450 °C. Phase formation was investigated by X-ray diffraction technique. The XRD analysis demonstrated that with increasing BFN content in (1−x)BZT–xBFN, the structural change occurred from the tetragonal to the cubic phase at room temperature. Changes in the physical and mechanical properties were then related to this structural transformation depending on the BFN content.

X-Ray Diffraction Study of Shape Memory in Uranium-Niobium Alloys

1982 ◽  
Vol 26 ◽  
pp. 307-312 ◽  
Author(s):  
D. A. Carpenter ◽  
R. A. Vandermeer
Keyword(s):  
Shape Memory ◽  
Diffraction Study ◽  
Strain Curve ◽  
X Ray Diffraction ◽  
Stress Strain Curve ◽  
Niobium Alloys ◽  
X Ray ◽  
Scan Time ◽  
Diffraction Patterns

An x-ray diffraction study of the reversible deformation inodes associated with the shape memory effect has been carried out on a series of uranium-niobium alloys near the monotectoid composition (6.2 wt. % Nb). Diffraction patterns were measured as a function of strain, in situ, while the specimens were under stress as part of an attempt to explain the “easy-flow”, low-strain plateau in the stress-strain curve. The alloys, consisting of highly twinned, metastable α” (monoclinic) and γ° (tetragonal) phases derived from the high-temperature BCC γ phase, produced broad, overlapping diffraction lines difficult to analyze by conventional techniques. One solution to this problem was to use a segmented step-scan technique so as to apportion the scan time to concentrate on the most difficult regions. This paper discusses data obtained from an α” alloy and a dual-phase α” + γ° alloy.

Crack Propagating and Stress-Promoted the Precipitate of Ni3Ti in NiTi Thin Films

2009 ◽  
Vol 417-418 ◽  
pp. 657-660 ◽  
Author(s):  
Yong Hua Li ◽  
F.L. Meng ◽  
Wei Tao Zheng ◽  
Y.M. Wang
Keyword(s):  
Thin Films ◽  
Parent Phase ◽  
Testing Machine ◽  
Strain Curve ◽  
Tensile Tests ◽  
X Ray Diffraction ◽  
Stress Strain Curve ◽  
Parallel Cracks ◽  
Peak Intensity ◽  
Two Stages

This study investigated the stress-induced crack propagation and precipitation in Ti-51.45at.%Ni thin films. Tensile tests were carried out on CSS-44100 electron universal testing machine. The strain rate was 1.1×10-4 s-1. The surface micrographs of the NiTi thin film were obtained using scanning electron microscopy (SEM). The precipitates were determined by X-ray diffraction (XRD) experiments (D8 GADDS). The results showed that a series of parallel cracks grew in the film and the cracks were equally spaced. The fracture toughness of the film was estimated, =0.96MPa∙m1/2. The minimum crack spacing was about . The stress-strain curve can be divided into two stages. The first linear stage corresponded to the elastic deformation of the parent phase. In the following stage, the serrations were considered to be the stress relaxation due to the cracks propagating and the precipitate grain transformation. During tension the (102) peak intensity of Ni3Ti phase increased with elongation increased. The precipitate orientation was same.

scholarly journals SHRIMP U-Th-Pb zircon dating of the granitoid massifs in the Malé Karpaty Mountains (Western Carpathians): evidence of Meso-Hercynian successive S- to I-type granitic magmatism

2009 ◽  
Vol 60 (5) ◽  
pp. 345-350 ◽  
Author(s):  
Milan Kohút ◽  
Pavel Uher ◽  
Marián Putiš ◽  
Martin Ondrejka ◽  
Sergey Sergeev ◽  
...  
Keyword(s):  
Granitic Rock ◽  
Granitic Rocks ◽  
Western Carpathians ◽  
Pb Isotope ◽  
Zircon Dating ◽  
Rock Samples ◽  
Isotope Method ◽  
Granitic Magmatism

SHRIMP U-Th-Pb zircon dating of the granitoid massifs in the Malé Karpaty Mountains (Western Carpathians): evidence of Meso-Hercynian successive S- to I-type granitic magmatismRepresentative granitic rock samples from the Malé Karpaty Mountains of the Western Carpathians (Slovakia) were dated by the SHRIMP U-Th-Pb isotope method on zircons. Oscillatory zoned zircons revealed concordant Mississippian magmatic ages: 355±5 Ma in Bratislava granodiorite, and 347±4 Ma in Modra tonalite. The results document nearly synchronous, successive Meso-Hercynian plutonic events from S-type to I-type granites. The Neo-Proterozoic inherited zircon cores (590±13 Ma) were identified in the Bratislava S-type granitic rocks whereas scarce Paleo-Proterozoic inherited zircons (1984±36 Ma) were detected within the Modra I-type tonalites.

scholarly journals Research on the Impact of Different Force Directions on the Mechanical Properties and Damage Evolution Law of Sandstone with Different Hole Diameters

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Fukun Xiao ◽  
Renhe Li ◽  
Le Xing
Keyword(s):  
Mechanical Properties ◽  
Acoustic Emission ◽  
Energy Conversion ◽  
Rock Sample ◽  
Strain Curve ◽  
Hole Diameter ◽  
Stress Strain Curve ◽  
Rock Samples ◽  
The Impact ◽  
Vertical Hole

In this research, a uniaxial acoustic emission experiment was conducted on rock samples with different positions and diameters of the hole, and an analysis was made on the impact of different hole positions and diameters on the mechanical properties, failure, energy conversion, and acoustic emission-caused damage characteristics and laws of the rock samples. The results reveal as follows: first, due to the existence of holes in rocks, the stress-strain curve changes at each stage, accompanied by multiple stress drops. And the peak strength gradually reduces with the increase in hole diameter. At different hole positions, the duration that the rock sample passes through at each stage of the stress-strain curve varies, and the peak strength of the rock with the vertical hole is greater than that of the rock with the horizontal hole. This indicates that the bearing capacity and stability of the rock sample with the vertical hole are greater than those of the rock sample with the horizontal hole of the same diameter. Second, by making a comparison on the failure characteristics of rock samples, it is found that the intact rock shows brittle failure. For the rock sample with the horizontal hole, symmetrical tensile cracks initially appear in the upper and lower parts of the hole and finally form shear failure. As for the rock sample with the vertical hole, Y-shape failure originally presents and eventually forms N-shape failure with the increase in hole diameter. Over a comparison with the failure pattern of an intact rock sample, it is demonstrated that the final failure pattern and crack expansion trend on the rock sample vary with the change in the hole position and diameter. Third, as obtained by comparing and analyzing the energy conversion of the rock with different diameters of the hole, the energy conversion in the rock is changed due to the existence of holes, and the increase in hole diameter causes a gradual decrease in the elastic energy stored in the rock and gradual increase in the dissipated energy. And by comparing the energy conversion of the rock with different positions of the hole, it is acquired that the elastic energy conversion ratio of the rock with the vertical hole is higher than that of the rock with the horizontal hole. Furthermore, an explanation was made on the difference in the failure processes of the two types of rocks from the perspective of energy conversion.

scholarly journals Textural Modifications during Recovery in Ti-Rich Ni-Ti Shape Memory Alloy Subjected to Low Level of Cold Work Reduction

2010 ◽  
Vol 636-637 ◽  
pp. 618-623 ◽  
Author(s):  
Andersan S. Paula ◽  
Karimbi Koosappa Mahesh ◽  
Norbert Schell ◽  
Francisco Manuel Braz Fernandes
Keyword(s):  
Shape Memory ◽  
Phase Transformations ◽  
Room Temperature ◽  
Cold Work ◽  
Strain Curve ◽  
X Ray Diffraction ◽  
Stress Strain Curve ◽  
Scanning Calorimetry ◽  
Low Level ◽  
Physical And Mechanical Characteristics

In shape memory alloys (SMA), the texture can be an interesting factor influencing the anisotropic physical and mechanical characteristics during the phase transformations. It is well known that the texture significantly influences the stress-strain curve and shape memory strain of NiTi SMA. The aim of the present experiment was to analyze the textural modifications in the Ti-rich Ni-Ti SMA after annealing at moderate (500°C for 30 min) and subsequent low level of cold work reduction (10% thickness reduction). The textural results were obtained by X-Ray Diffraction (XRD) during thermal cycling in three points: (i) at room temperature (B19’ phase, after cold work), (ii) at 180°C (B2 phase), and (iii) at room temperature (B19’ phase, after cooling from 180°C). The phase transformations were characterized by Differential Scanning Calorimetry (DSC) and XRD.

Identification of acid-insoluble filter-plugging compounds and optimal acid-washing procedures for tubular backpulse pressure filters

TAPPI Journal ◽  
2011 ◽  
Vol 10 (1) ◽  
pp. 17-23
Author(s):  
KEVIN TAYLOR ◽  
RICH ADDERLY ◽  
GAVIN BAXTER
Keyword(s):  
Calcium Sulfate ◽  
Membrane Filter ◽  
Sulfamic Acid ◽  
Xrd Analysis ◽  
Metal Sulfides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gypsum Formation ◽  
Acid Washing ◽  
Hydrolysis Of

Over time, performance of tubular backpulse pressure filters in kraft mills deteriorates, even with regular acid washing. Unscheduled filter replacement due to filter plugging results in significant costs and may result in mill downtime. We identified acid-insoluble filter-plugging materials by scanning electron microscope/energy-dispersion X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis in both polypropylene and Gore-Tex™ membrane filter socks. The major filter-plugging components were calcium sulfate (gypsum), calcium phosphate (hydroxylapatite), aluminosilicate clays, metal sulfides, and carbon. We carried out detailed sample analysis of both the standard acid-washing procedure and a modified procedure. Filter plugging by gypsum and metal sulfides appeared to occur because of the acid-washing procedure. Gypsum formation on the filter resulted from significant hydrolysis of sulfamic acid solution at temperatures greater than 130°F. Modification of the acid-washing procedure greatly reduced the amount of gypsum and addition of a surfactant to the acid reduced wash time and mobilized some of the carbon from the filter. With surfactant, acid washing was 95% complete after 40 min.

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