scholarly journals Structure and properties of masonry mortars based on ceramic microspheres

2018 ◽  
Vol 251 ◽  
pp. 01045 ◽  
Author(s):  
Vyacheslav Semenov
Keyword(s):  
High Performance ◽  
Chemical Interaction ◽  
Structural Characteristics ◽  
Test Methods ◽  
Standard Test ◽  
Cement Matrix ◽  
X Ray Diffraction ◽  
Resource Saving ◽  
Composition And Structure ◽  
Masonry Mortar

Modern requirements in the field of energy and resource saving determines the need to apply effective fencing structures. To ensure the thermal homogeneity of the structures erected with small-piece masonry elements (ceramic and light-weight concrete units etc.), it is necessary to use lightweight mortars. One of the most effective methods to obtain such mortars is the introduction of hollow ceramic microspheres as a filler into their composition. The purpose of this work is studying of the composition and structure of a cement masonry mortar with hollow ceramic microspheres and modifying additives in correlation with its properties. The methods of thermogravimetric analysis, scanning electron microscopy, X-ray diffraction and standard test methods for the masonry mortars were used. The effect of the structural characteristics of the composite on the properties of final product was analyzed. It is established that the microstructure of the modified mortar samples is more compact in compare with basic composition, and the surface of the microspheres is covered by the products of the chemical interaction of its walls with the cement matrix. The aforesaid research allowed to obtain the high-performance lightweight mortars with hollow ceramic microspheres.

scholarly journals Enhancing the Mechanical Properties of Glass-Ionomer Dental Cements: A Review

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2510 ◽  
Author(s):  
John W. Nicholson ◽  
Sharanbir K. Sidhu ◽  
Beata Czarnecka
Keyword(s):  
Test Methods ◽  
Standard Test ◽  
Literature Survey ◽  
Cement Matrix ◽  
Particle Sizes ◽  
Clinical Use ◽  
Current Clinical Practice ◽  
Glass Ionomer ◽  
Limited Extent ◽  
Substantial Body

This paper reviews the strategies that have been reported in the literature to attempt to reinforce glass-ionomer dental cements, both conventional and resin-modified. These cements are widely used in current clinical practice, but their use is limited to regions where loading is not high. Reinforcement might extend these applications, particularly to the posterior dentition. A variety of strategies have been identified, including the use of fibres, nanoparticles, and larger particle additives. One problem revealed by the literature survey is the limited extent to which researchers have used International Standard test methods. This makes comparison of results very difficult. However, it does seem possible to draw conclusions from this substantial body of work and these are (1) that powders with conventional particle sizes do not reinforce glass-ionomer cements, (2) certain fibres and certain nanoparticles give distinct improvements in strength, and (3) in the case of the nanoparticles these improvements are associated with differences in the morphology of the cement matrix, in particular, a reduction in the porosity. Despite these improvements, none of the developments has yet been translated into clinical use.

scholarly journals Thermal Analysis and Crystal Structure of Poly(Acrylonitrile-Co-Itaconic Acid) Copolymers Synthesized in Water

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 221
Author(s):  
Hailong Zhang ◽  
Ling Quan ◽  
Aijun Gao ◽  
Yuping Tong ◽  
Fengjun Shi ◽  
...  
Keyword(s):  
Carbon Fibers ◽  
High Performance ◽  
Thermal Stabilization ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Air Atmosphere ◽  
Composition And Structure ◽  
Average Size ◽  
Dsc Curves

The composition and structure of polyacrylonitrile (PAN) precursors play an important role during thermal stabilization, which influences the properties of the resulting carbon fibers. In this paper, PAN homopolymer and PAN-itaconic (IA) copolymers with different IA contents were synthesized by aqueous phase precipitation polymerization. The effects of IA content on the structure and thermal properties were studied using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The morphology of PAN polymers showed that the average size of the PAN particles increased with the increase of IA content in the feed. The content of the IA comonomer on the copolymers was quantitatively characterized by the relative absorbance intensity (A1735/A2243) in FTIR spectrum. With the increase of IA content in the feed, PAN-IA copolymers exhibited lower degree of crystallinity and crystal size than the control PAN homopolymer. The results from DSC curves indicated that PAN-IA1.0 copolymers had lower initial exothermic temperature (192.4 °C) and velocity of evolving heat (6.33 J g−1 °C−1) in comparison with PAN homopolymer (Ti = 238.1 °C and ΔH/ΔT = 34.6 J g−1 °C−1) in an air atmosphere. TGA results suggested that PAN-IA1.0 copolymers had higher thermal stability than PAN homopolymer, which can form a ladder structure easier during thermal processing. Therefore, PAN-IA1.0 copolymers would be a suitable candidate for preparing high performance PAN based carbon fibers.

GaP-TiO2-C Nanocomposite as High-Performance Sodium-Ion Batteries Anode

2021 ◽  
Vol 21 (7) ◽  
pp. 3897-3902
Author(s):  
Vo Pham Hoang Huy ◽  
Jaehyun Hur
Keyword(s):  
Current Density ◽  
High Performance ◽  
Structural Characteristics ◽  
Rate Capability ◽  
Cycling Performance ◽  
High Energy ◽  
X Ray Diffraction ◽  
Volume Changes ◽  
X Ray ◽  
Transmission Electron

GaP-TiO2-C composites with three different C concentrations are synthesized via a high-energy mechanical milling. The analysis of the structural characteristics of GaP-TiO2-C using X-ray diffraction and high-resolution transmission electron microscopy reveals that the nanosized GaP and TiO2 crystallites are uniformly distributed in the amorphous C matrix. The GaP-TiO2-C(20%) composite exhibits a high Na storage capacity of 266 mAh g−1 at the current density of 0.1 A g−1 after 100 cycles, and the remarkable rate capability of 224 mAh g−1 even at the higher current density of 10 A g−1. In addition, the GaP-TiO2-C(20%) composite presents great cycling performance and the capacity of 213 mAh g−1 at the current density of 0.5 A g−1 after 300 cycles. The outstanding cycling performance and rate capability of GaP-TiO2-C(20%) anode can be attributed to the favorable morphology of GaP-TiO2-C composite that accommodates large volume changes during cycling.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

scholarly journals Flux Method Growth of Large Size Group IV–V 2D GeP Single Crystals and Photoresponse Application

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 235
Author(s):  
Shuqi Zhao ◽  
Tongtong Yu ◽  
Ziming Wang ◽  
Shilei Wang ◽  
Limei Wei ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Single Crystals ◽  
High Performance ◽  
Group Iv ◽  
X Ray Diffraction ◽  
High Quality ◽  
Practical Applications ◽  
Large Size ◽  
Growth Method ◽  
Polarized Raman

Two-dimensional (2D) materials driven by their unique electronic and optoelectronic properties have opened up possibilities for their various applications. The large and high-quality single crystals are essential to fabricate high-performance 2D devices for practical applications. Herein, IV-V 2D GeP single crystals with high-quality and large size of 20 × 15 × 5 mm3 were successfully grown by the Bi flux growth method. The crystalline quality of GeP was confirmed by high-resolution X-ray diffraction (HRXRD), Laue diffraction, electron probe microanalysis (EPMA) and Raman spectroscopy. Additionally, intrinsic anisotropic optical properties were investigated by angle-resolved polarized Raman spectroscopy (ARPRS) and transmission spectra in detail. Furthermore, we fabricated high-performance photodetectors based on GeP, presenting a relatively large photocurrent over 3 mA. More generally, our results will significantly contribute the GeP crystal to the wide optoelectronic applications.

scholarly journals Enhancement of Chloroprene/Natural/Butadiene Rubber Nanocomposite Properties Using Organoclays and Their Combination with Carbon Black as Fillers

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1085
Author(s):  
Patricia Castaño-Rivera ◽  
Isabel Calle-Holguín ◽  
Johanna Castaño ◽  
Gustavo Cabrera-Barjas ◽  
Karen Galvez-Garrido ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Black ◽  
High Performance ◽  
Rubber Matrix ◽  
Butadiene Rubber ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rubber Blends ◽  
Ft Ir ◽  
Chloroprene Rubber

Organoclay nanoparticles (Cloisite® C10A, Cloisite® C15) and their combination with carbon black (N330) were studied as fillers in chloroprene/natural/butadiene rubber blends to prepare nanocomposites. The effect of filler type and load on the physical mechanical properties of nanocomposites was determined and correlated with its structure, compatibility and cure properties using Fourier Transformed Infrared (FT-IR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA) and rheometric analysis. Physical mechanical properties were improved by organoclays at 5–7 phr. Nanocomposites with organoclays exhibited a remarkable increase up to 46% in abrasion resistance. The improvement in properties was attributed to good organoclay dispersion in the rubber matrix and to the compatibility between them and the chloroprene rubber. Carbon black at a 40 phr load was not the optimal concentration to interact with organoclays. The present study confirmed that organoclays can be a reinforcing filler for high performance applications in rubber nanocomposites.

scholarly journals High-performance quasi-2D perovskite light-emitting diodes: from materials to devices

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Li Zhang ◽  
Changjiu Sun ◽  
Tingwei He ◽  
Yuanzhi Jiang ◽  
Junli Wei ◽  
...  
Keyword(s):  
Energy Transfer ◽  
High Performance ◽  
Light Emitting Diodes ◽  
Structural Characteristics ◽  
Quantum Yields ◽  
Research Directions ◽  
Light Emitting ◽  
Perovskite Materials ◽  
Quantum Confinement Effects ◽  
Semiconducting Properties

AbstractQuasi-two-dimensional (quasi-2D) perovskites have attracted extraordinary attention due to their superior semiconducting properties and have emerged as one of the most promising materials for next-generation light-emitting diodes (LEDs). The outstanding optical properties originate from their structural characteristics. In particular, the inherent quantum-well structure endows them with a large exciton binding energy due to the strong dielectric- and quantum-confinement effects; the corresponding energy transfer among different n-value species thus results in high photoluminescence quantum yields (PLQYs), particularly at low excitation intensities. The review herein presents an overview of the inherent properties of quasi-2D perovskite materials, the corresponding energy transfer and spectral tunability methodologies for thin films, as well as their application in high-performance LEDs. We then summarize the challenges and potential research directions towards developing high-performance and stable quasi-2D PeLEDs. The review thus provides a systematic and timely summary for the community to deepen the understanding of quasi-2D perovskite materials and resulting LED devices.

Depositing High-Performance Conductive Thin Films by Using Atomic Layer Deposition

2015 ◽  
Vol 764-765 ◽  
pp. 138-142 ◽  
Author(s):  
Fa Ta Tsai ◽  
Hsi Ting Hou ◽  
Ching Kong Chao ◽  
Rwei Ching Chang
Keyword(s):  
Thin Films ◽  
Atomic Layer Deposition ◽  
High Performance ◽  
Atomic Layer ◽  
Electric Properties ◽  
X Ray Diffraction ◽  
Layer Deposition ◽  
Azo Thin Film ◽  
Aluminum Doped Zinc Oxide ◽  
Conductive Thin Films

This work characterizes the mechanical and opto-electric properties of Aluminum-doped zinc oxide (AZO) thin films deposited by atomic layer deposition (ALD), where various depositing temperature, 100, 125, 150, 175, and 200 °C are considered. The transmittance, microstructure, electric resistivity, adhesion, hardness, and Young’s modulus of the deposited thin films are tested by using spectrophotometer, X-ray diffraction, Hall effect analyzer, micro scratch, and nanoindentation, respectively. The results show that the AZO thin film deposited at 200 °C behaves the best electric properties, where its resistance, Carrier Concentration and mobility reach 4.3×10-4 Ωcm, 2.4×1020 cm-3, and 60.4 cm2V-1s-1, respectively. Furthermore, microstructure of the AZO films deposited by ALD is much better than those deposited by sputtering.

scholarly journals Comparison of Two Intergranular Corrosion Tests on EN AW-6016 Sheet Material

2021 ◽  
Vol 11 (11) ◽  
pp. 5294
Author(s):  
Peer Decker ◽  
Ines Zerbin ◽  
Luisa Marzoli ◽  
Marcel Rosefort
Keyword(s):  
Optical Microscopy ◽  
Intergranular Corrosion ◽  
Sheet Material ◽  
Test Methods ◽  
Standard Test ◽  
Corrosion Depth ◽  
Corrosion Tests ◽  
Automotive Company ◽  
Test Parameters

Two different intergranular corrosion tests were performed on EN AW-6016 sheet material, an ISO 11846:1995-based test with varying solution amounts and acid concentrations, and a standard test of an automotive company (PV1113, VW-Audi). The average intergranular corrosion depth was determined via optical microscopy. The differences in the intergranular corrosion depths were then discussed with regard to the applicability and quality of the two different test methods. The influence of varying test parameters for ISO 11846:1995 was discussed as well. The determined IGC depths were found to be strongly dependent on the testing parameters, which will therefore have a pronounced influence on the determined IGC susceptibility of a material. In general, ISO 11846:1995 tests resulted in a significantly lower corrosion speed, and the corrosive attack was found to be primarily along grain boundaries.

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