scholarly journals Microstructures, Mineral Compositions, and Mechanical Properties of Red-Layers in Southern China

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Huizhi Zhang ◽  
Jifeng Liu
Keyword(s):  
Mechanical Properties ◽  
Structural Strength ◽  
Southern China ◽  
Damage Mechanism ◽  
Mechanical Tests ◽  
Moisture Migration ◽  
Clay Particles ◽  
Widespread Distribution ◽  
Mineral Compositions ◽  
Scanning Electron

In order to reveal the water-induced damage mechanism and mechanical properties of red-layers in Southern China, typical red-layer samples are experimentally studied by scanning electron microscope (SEM), energy spectrum analysis, XRD, and mechanical tests. The results show that some red-layer samples contain a large number of smectite and illite-smectite mixed-layer clay minerals and their microstructures are mainly stacked microaggregates in which mutual agglomeration is formed by flake and tabular clay particles. Widespread distribution micropores and fractures in microaggregates provide the necessary moisture migration channels. The various cemented materials produce a kind of irreversible structural strength, and this strength is vulnerable for the aqueous medium conditions. The influence of microstructures and mineral compositions on red-layer mechanical properties is discussed. The results could provide the reference for further research about the water-induced damage mechanism of red-layers in Southern China.

Effect of Functionalized MWCNT on the Mechanical and Dielectric Properties of PMMA Nanocomposites

2018 ◽  
Vol 18 (06) ◽  
pp. 1850035
Author(s):  
Punyapriya Mishra ◽  
Narasingh Deep ◽  
Sagarika Pradhan ◽  
Vikram G. Kamble
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Dielectric Constant ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Dielectric Properties ◽  
Conductive Polymer ◽  
Mechanical Tests ◽  
Surface Structures ◽  
Scanning Electron

Carbon nanotubes (CNTs) are widely explained in fundamental blocks of nanotechnology. These CNTs exhibit much greater tensile strength than steel, even almost similar to copper, but they have higher ability to carry much higher currents, they seem to be a magical material with all these mentioned properties. In this paper, an attempt has been made to incorporate this wonder material, CNT, (with varying percentages) in polymeric matrix (Poly methyl methacrylate (PMMA)) to create a new conductive polymer composite. Various mechanical tests were carried out to evaluate its mechanical properties. The dielectric properties such as dielectric loss and dielectric constant were evaluated with the reference of temperature and frequency. The surface structures were analyzed by Scanning Electron Microscope (SEM).

Scanning Electron Microscope in Rocks and their Comparison with Physical-Mechanical Properties

2020 ◽  
Vol 841 ◽  
pp. 114-118
Author(s):  
Marco Antonio Navarrete Seras ◽  
Francisco Javier Domínguez Mota ◽  
Elia Mercedes Alonso Guzmán ◽  
Wilfrido Martínez Molina ◽  
Hugo Luis Chávez García ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Mechanical Tests ◽  
Structural Element ◽  
Concrete Mixtures ◽  
Hydraulic Concrete ◽  
Stone Materials ◽  
Historical Monuments ◽  
Scanning Electron

. Banks of stone materials from Michoacán, Mexico were characterized, since they are used in the construction of infrastructure in the area. With these materials are made hydraulic concrete mixtures or asphalt mixtures, foundations, paving stones and in restoration of historical monuments. The rocks analyzed and characterized, come from banks of volcanic stone materials and banks of crushed stone materials, which were subjected to mechanical tests such as uniaxial compression resistance (UCR), in addition was used scanning electron microscope (SEM), by means of which the characterization was carried out, obtaining morphological information of the material. The comparison of physical-mechanical properties with the elements they possess is important to estimate their behavior within ceramic matrices or as a structural element.

Prediction and Verification of Compatibility of MMT Nanofiller in PA6 Matrix

2014 ◽  
Vol 635 ◽  
pp. 194-197 ◽  
Author(s):  
Branislav Duleba ◽  
Emil Spišák ◽  
Janusz W. Sikora ◽  
Ľudmila Dulebova
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Impact Test ◽  
Mechanical Tests ◽  
Cloisite 30B ◽  
Sem Study ◽  
Hamaker Constants ◽  
Adhesion Work ◽  
Test Impact ◽  
Scanning Electron

This contribution deals about study of mechanical properties and compatibility between PA6 polymer as matrix and modified and unmodified montmorillonite clay nanofiller Cloisite. For this purposes in the first part of study the Hamaker constants, Adhesion work and B parameter for systems PA6/Cloisite 30B, PA6/Cloisite 93A and Pa6/Cloisite Na+ were calculated and compared. The second part of article consists of mechanical tests (tensile test, impact test) of moulded samples and Scanning Electron Microscope (SEM) study of these samples.

Preparation and Mechanical Properties of Modified Magnesium Oxysulfate Cement Incorporating Alkali Conditioner

2020 ◽  
Vol 12 (10) ◽  
pp. 1558-1567
Author(s):  
Shengbin Li ◽  
Haoqian Ren ◽  
Qin Wu ◽  
Yiyang Ye
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Calcium Carbonate ◽  
Mechanical Test ◽  
Mechanical Tests ◽  
Molar Ratio ◽  
Buffer Solution ◽  
Magnesium Oxysulfate ◽  
Scanning Electron

Magnesium oxysulfate cement is an ecological gas-hardening cementitious material. The cement has a complex system, insufficient hydration, and unstable hydration products, so that the cement mechanical property is poor. In this study, calcium chloride/carbon dioxide/weak buffer solution is used to generate alkaline additive, namely vaterite calcium carbonate. The additive material is characterized by scanning electron microscopy and X-ray diffraction, and then the optimal MgO/MgSO4/H2O molar ratio after calcium carbonate is added to magnesium oxysulfate cement, the optimal laying method and reasonable amount of vaterite calcium carbonate are analyzed by mechanical tests. In the experiment, the basic additive is characterized firstly. It is found that the XRD of the additive mainly includes the peaks of calcite and vaterite. It can be seen by scanning electron microscopy that many calcites and vaterites are not formed, the calcites are accumulated more, and there is a large number of particles, which are not appeared before. In the mechanical test of magnesium sulfide cement, the mechanical properties of magnesium oxysulfate cement will increase firstly and then decrease with the increase of MgO/MgSO4 molar ratio in the way of long-cut calcium carbonate for reinforcement. Compared with the layout of long-cut calcium carbonate-magnesium oxysulfate cement, the layout of short-cut calcium carbonate-magnesium oxysulfate cement can enhance the toughness of the modified cement, increase the amount of calcium carbonate, and improve the flexural strength and toughness index of the modified magnesium oxysulfate cement. The blending ratio is better to be 6%. Based on above researches and demonstrations, blending the calcium carbonate-based alkaline additive can effectively improve the mechanical properties of the magnesium oxysulfate cement.

Nanotechnology and Earth Construction: The Mechanical Properties of Adobe Brick Stabilized by Laponite Nanoparticles

2014 ◽  
Vol 983 ◽  
pp. 63-66
Author(s):  
Francesca Scalisi
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Chemical Analysis ◽  
Flexural Strength ◽  
Mechanical Characteristics ◽  
Cost Effective ◽  
Mechanical Tests ◽  
Earth Construction ◽  
The Earth ◽  
Scanning Electron

The contribution describes the experimental analysis for the improvement of the mechanical properties of samples of earth with the addition of Laponite nanoparticles. Were made two types of samples: the first consisting of soil, sand and water; the second consisting of soil, water, sand and Laponite nanoparticles. The operations performed were: chemical analysis of soil and sand; preparation of samples; Scanning Electron Microscope (SEM) observation of samples for the distribution of the elements, especially the Laponite nanoparticles; testing of compression strength and flexural strength of two types of samples; comparisons of the resulted of the mechanical tests. The improvement of the mechanical characteristics of the earth material using nanotechnology, will increase the use of eco-friendly, non-toxic, cost effective, available materials in architecture.

Wool felt: Characterization, comparison with other materials, and investigation of its use in hospital accessories

2020 ◽  
pp. 004051752091583
Author(s):  
Heloisa Nazaré dos Santos ◽  
Sebastiana Luiza Bragança Lana Lara ◽  
José Henrique Martins Neto
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Mechanical Tests ◽  
Hospital Environment ◽  
Dry Process ◽  
Washing Process ◽  
Mechanical Scanning ◽  
Scanning Electron

This article presents groundbreaking research on wool felt for use in hospital accessories. The results of mechanical, scanning electron microscopy (SEM), chemical, flammability, and microbiological tests are presented, as well as research on the acceptability of three wool felt hospital accessories (i.e. sheet cover, pillowcase cover, and insole). An innovative approach was utilized to compare the mechanical properties of unwashed and washed wool felt samples by three different washing machines, with textiles commonly used in hospital (i.e. nonwoven of polyester felt, woven of 100% cotton, and woven of a blend of 67% cotton and 33% polyester). The mechanical tests showed that the wool felt had tensile resistance similar to that of polyester felt, superior elongation to the 100% cotton and the blend, inferior tearing stress, lower resistance to slippage, and good pilling resistance. After washing, the wool felt washed with the extractor washer and dry washer increased their tensile strength 33% and 19%; the tear strength did not change; the slippage decreased; and the samples washed with the dry washer showed 14% less pilling than those not washed. The SEM tests showed differences in appearance of the fibers after the washing processes. Chemical tests revealed that 0.11% of lanolin was retained in the wool felt after washing the samples with the dry process. The flammability tests showed the dependence of carbonization length with the wool felt washing process. The volunteers showed a good acceptance of the wool felt accessories emphasizing the feeling of freshness, release of pain, and reduction in sweating and unpleasant odors. Microbiological tests showed growth in the insoles of the bacterium Staphylococcus aureus and the fungus Candida albicans, commonly found in the hospital environment.

Effect of sodium bicarbonate treatment on mechanical properties of flax-reinforced epoxy composite materials

2017 ◽  
Vol 52 (8) ◽  
pp. 1061-1072 ◽  
Author(s):  
V Fiore ◽  
T Scalici ◽  
A Valenza
Keyword(s):  
Mechanical Properties ◽  
Sodium Bicarbonate ◽  
Epoxy Composite ◽  
Sodium Bicarbonate Solution ◽  
Cost Effective ◽  
Mechanical Tests ◽  
Epoxy Composites ◽  
Effective Surface ◽  
Fracture Surfaces ◽  
Scanning Electron

This paper deals with the evaluation of the effect of an eco-friendly and cost-effective surface treatment based on the use of sodium bicarbonate on the mechanical properties of flax-reinforced epoxy composites. To this aim, unidirectional fabrics were soaked for five days in 5 and 10% in weight of sodium bicarbonate solution at 25℃. Quasi-static and dynamic mechanical tests were performed and the fracture surfaces of the composites were analyzed through scanning electron microscopy. Results evidenced that this treatment improves the fiber–matrix adhesion thus increasing the performances of the composites. Treating the fabrics with 10% w/w of bicarbonate solution leads to improvements of ∼20 and ∼45% in tensile strength and modulus of the composites, respectively, compared to untreated ones. Furthermore, by increasing the concentration, negligible changes in the glass transition temperature and reductions in the tanδ peak heights were found. The observation of the fracture surfaces confirmed the beneficial effect of the proposed treatment.

An evaluation of tribological and mechanical properties of Al-Si-Cu alloy with nano-clay particles reinforcement

2019 ◽  
Vol 233 (19-20) ◽  
pp. 7062-7076 ◽  
Author(s):  
Fahimeh Kamali ◽  
Mahboobeh Azadi
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Elastic Modulus ◽  
Base Alloy ◽  
Nano Composites ◽  
Clay Particles ◽  
Cu Alloy ◽  
Nano Clay ◽  
Scanning Electron

In this paper, comparative evaluations on the mechanical properties of Al-Si-Cu alloy reinforced by nano-clay mineral particles were carried out. Such nano-composites contained 1 wt% nano-clay particles and were manufactured through the stir casting with various stirring temperatures and times. Mechanical behaviors such as the hardness and compressive strengths, the elastic modulus and wear properties were studied. The microstructural observations were conducted by the optical and the scanning electron microscopy. Field emission scanning electron microscopy (FESEM) images showed that nano-clay particles distributed uniformly in the aluminum matrix for the nano-composite fabricated at 800 ℃ and was stirred for 2 min. Besides, the lower stirring temperature of 750 ℃ caused a degree of clustering with a size of lower than 200 nm in some places. In comparison with the base alloy, an improvement of 5% to 33% in Brinell hardness value observed for various nano-composites. The wear resistance of various nano-composites also increased two to five times regarding the base alloy. The parameter of µ/E. H2 would predict the wear rate for all specimens. It was found that nano-composites fabricated at the temperature of 750 ℃ exhibited the lower porosity content and the higher ultimate compressive strength, and the elastic modulus.

Electron Microscopic Observation of the Longitudinal Organization of Poly (p-Phenylene Terephthalamide) Fibers

1982 ◽  
Vol 40 ◽  
pp. 680-681
Author(s):  
Li Li-Sheng ◽  
L.F. Allard ◽  
W.C. Bigelow
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Microscopic Observation ◽  
Electron Microscopic Observation ◽  
Electron Microscopic ◽  
Aromatic Polyamides ◽  
Radial Arrangement ◽  
Scanning Electron ◽  
Better Than

The aromatic polyamides form a class of fibers having mechanical properties which are much better than those of aliphatic polyamides. Currently, the accepted morphology of these fibers as proposed by M.G. Dobb, et al. is a radial arrangement of pleated sheets, with the plane of the pleats parallel to the axis of the fiber. We have recently obtained evidence which supports a different morphology of this type of fiber, using ultramicrotomy and ion-thinning techniques to prepare specimens for transmission and scanning electron microscopy.

Effect of silver nitrate on some mechanical properties of heat polymerizing acrylic resins

2019 ◽  
Vol 14 (1) ◽  
pp. 110
Author(s):  
Assiss. Prof. Dr. Sabiha Mahdi Mahdi ◽  
Dr. Firas Abd K. Abd K.
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Silver Nitrate ◽  
Surface Hardness ◽  
Mechanical Tests ◽  
Hardness Tester ◽  
Acrylic Resins ◽  
The Difference

Aim: The aimed study was to evaluate the influence of silver nitrate on surfacehardness and tensile strength of acrylic resins.Materials and methods: A total of 60 specimens were made from heat polymerizingresins. Two mechanical tests were utilized (surface hardness and tensile strength)and 4 experimental groups according to the concentration of silver nitrate used.The specimens without the use of silver nitrate were considered as control. Fortensile strength, all specimens were subjected to force till fracture. For surfacehardness, the specimens were tested via a durometer hardness tester. Allspecimens data were analyzed via ANOVA and Tukey tests.Results: The addition of silver nitrate to acrylic resins reduced significantly thetensile strength. Statistically, highly significant differences were found among allgroups (P≤0.001). Also, the difference between control and experimental groupswas highly significant (P≤0.001). For surface hardness, the silver nitrate improvedthe surface hardness of acrylics. Highly significant differences were statisticallyobserved between control and 900 ppm group (P≤0.001); and among all groups(P≤0.001)with exception that no significant differences between control and150ppm; and between 150ppm and 900ppm groups(P>0.05).Conclusion: The addition of silver nitrate to acrylics reduced significantly the tensilestrength and improved slightly the surface hardness.

Sign in / Sign up

Export Citation Format

Share Document