scholarly journals Mechanical and Fracture Properties of Long Fiber Reinforced Geopolymer Composites

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5183
Author(s):  
Kinga Korniejenko ◽  
Beata Figiela ◽  
Krzysztof Miernik ◽  
Celina Ziejewska ◽  
Joanna Marczyk ◽  
...  
Keyword(s):  
Bending Strength ◽  
Volume Ratio ◽  
Fold Increase ◽  
Aramid Fiber ◽  
European Standard ◽  
River Sand ◽  
Fracture Properties ◽  
Strength Tests ◽  
Mechanical And Fracture Properties ◽  
Geopolymer Composites

The aim of the article is to analyze the structure and mechanical properties in terms of the cracking mechanics of geopolymer composites based on fly ash and river sand, as well as metakaolin and river sand with three types of reinforcement material: glass fiber, carbon fiber, and aramid fiber, in terms of their use in additive manufacturing. Geopolymer composites were reinforced with fibers in a volume ratio of 0.5%, 1.0%, and 2.0%. Subsequently, these samples were subjected to bending strength tests in accordance with the European standard EN 12390-3. The addition of fibers significantly improved the bending strength of all composites made of metakaolin and sand. The reinforcement with aramid fiber in the amount of 2.0% resulted in more than a 3-fold increase in strength compared to the reinforcement-free composites. An analysis of the morphology of the fibers was carried out on the basis of photos taken from an electron microscope. The correct addition of fibers changes the nature of the fracture from brittle to more ductile and reduces the number of cracks in the material.

scholarly journals Fracture Behavior of Long Fiber Reinforced Geopolymer Composites at Different Operating Temperatures

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 482
Author(s):  
Kinga Korniejenko ◽  
Beata Figiela ◽  
Celina Ziejewska ◽  
Joanna Marczyk ◽  
Patrycja Bazan ◽  
...  
Keyword(s):  
Fracture Behavior ◽  
Bending Strength ◽  
Aramid Fiber ◽  
Fine Aggregate ◽  
River Sand ◽  
Main Research ◽  
Glass Carbon ◽  
Different Temperatures ◽  
Almost All ◽  
Geopolymer Composites

The aim of this article was to analyze the fracture behavior of geopolymer composites based on fly ash or metakaolin with fine aggregate and river sand, with three types of reinforcement: glass, carbon, and aramid fiber, at three different temperatures, approximately: 3 °C, 20 °C, and 50 °C. The temperatures were selected as a future work temperature for composites designed for additive manufacturing technology. The main research method used was bending strength tests in accordance with European standard EN 12390-5. The results showed that the addition of fibers significantly improved the bending strength of all composites. The best results at room temperature were achieved for the metakaolin-based composites and sand reinforced with 2% wt. aramid fiber—17 MPa. The results at 50 °C showed a significant decrease in the bending strength for almost all compositions, which are unexpected results, taking into account the fact that geopolymers are described as materials dedicated to working at high temperatures. The test at low temperature (ca. 3 °C) showed an increase in the bending strength for almost all compositions. The grounds of this type of behavior have not been clearly stated; however, the likely causes of this are discussed.

Micromechanics Measurements Applied to Integrated Circuit Microelectronics

1997 ◽  
Vol 473 ◽  
Author(s):  
David R. Clarke
Keyword(s):  
Integrated Circuits ◽  
Integrated Circuit ◽  
Fracture Resistance ◽  
Interface Fracture ◽  
New Techniques ◽  
Fracture Properties ◽  
Engineered Structures ◽  
Mechanical And Fracture Properties ◽  
Interconnect Lines ◽  
Metallic Interconnect

ABSTRACTAs in other engineered structures, fracture occasionally occurs in integrated microelectronic circuits. Fracture can take a number of forms including voiding of metallic interconnect lines, decohesion of interfaces, and stress-induced microcracking of thin films. The characteristic feature that distinguishes such fracture phenomena from similar behaviors in other engineered structures is the length scales involved, typically micron and sub-micron. This length scale necessitates new techniques for measuring mechanical and fracture properties. In this work, we describe non-contact optical techniques for probing strains and a microscopic “decohesion” test for measuring interface fracture resistance in integrated circuits.

Novel Applications of Nanotechnology in Controlling HIV and HSV Infections

2020 ◽  
Vol 12 ◽  
Author(s):  
Sai Akilesh M ◽  
Ashish Wadhwani
Keyword(s):  
Drug Delivery ◽  
Viral Infections ◽  
Polymeric Nanoparticles ◽  
Volume Ratio ◽  
Fold Increase ◽  
Multi Drug Resistance ◽  
Health Crisis ◽  
Pharmaceutical Properties ◽  
Simplex Virus ◽  
The Impact

: Infectious diseases have been prevalent since many decades and viral pathogens have caused global health crisis and economic meltdown on a devastating scale. High occurrence of newer viral infections in the recent years, in spite of the progress achieved in the field of pharmaceutical sciences defines the critical need for newer and more effective antiviral therapies and diagnostics. The incidence of multi-drug resistance and adverse effects due to the prolonged use of anti-viral therapy is also a major concern. Nanotechnology offers a cutting edge platform for the development of novel compounds and formulations for biomedical applications. The unique properties of nano-based materials can be attributed to the multi-fold increase in the surface to volume ratio at the nano-scale, tunable surface properties of charge and chemical moieties. Idealistic pharmaceutical properties such as increased bioavailability and retention times, lower toxicity profiles, sustained release formulations, lower dosage forms and most importantly, targeted drug delivery can be achieved through the approach of nanotechnology. The extensively researched nano-based materials are metal and polymeric nanoparticles, dendrimers and micelles, nano-drug delivery vesicles, liposomes and lipid based nanoparticles. In this review article, the impact of nanotechnology on the treatment of Human Immunodeficiency Virus (HIV) and Herpes Simplex Virus (HSV) viral infections during the last decade are outlined.

scholarly journals Utilization of Birch Bark as an Eco-Friendly Filler in Urea-Formaldehyde Adhesives for Plywood Manufacturing

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 511
Author(s):  
Roman Réh ◽  
Ľuboš Krišťák ◽  
Ján Sedliačik ◽  
Pavlo Bekhta ◽  
Monika Božiková ◽  
...  
Keyword(s):  
Bending Strength ◽  
Urea Formaldehyde ◽  
Formaldehyde Emission ◽  
Birch Bark ◽  
Gravimetric Analysis ◽  
European Standard ◽  
Scanning Calorimetry ◽  
Wood Processing ◽  
Fagus Sylvatica L ◽  
Positive Effect

The potential of using ground birch (Betula verrucosa Ehrh.) bark as an eco-friendly additive in urea-formaldehyde (UF) adhesives for plywood manufacturing was investigated in this work. Five-ply plywood panels were fabricated in the laboratory from beech (Fagus sylvatica L.) veneers bonded with UF adhesive formulations comprising three addition levels of birch bark (BB) as a filler (10%, 15%, and 20%). Two UF resin formulations filled with 10% and 20% wheat flour (WF) were used as reference samples. The mechanical properties (bending strength, modulus of elasticity and shear strength) of the laboratory-fabricated plywood panels, bonded with the addition of BB in the adhesive mixture, were evaluated and compared with the European standard requirements (EN 310 and EN 314-2). The mechanical strength of the plywood with the addition of BB in the adhesive mixture is acceptable and met the European standard requirements. Markedly, the positive effect of BB in the UF adhesive mixture on the reduction of formaldehyde emission from plywood panels was also confirmed. Initially, the most significant decrease in formaldehyde release (up to 14%) was measured for the plywood sample, produced with 15% BB. After four weeks, the decrease in formaldehyde was estimated up to 51% for the sample manufactured with 20% BB. The performed differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and derivative thermogravimetry (DTG), also confirmed the findings of the study. As this research demonstrated, BB as a waste or by-product of wood processing industry, can be efficiently utilized as an environmentally friendly, inexpensive alternative to WF as a filler in UF adhesive formulations for plywood manufacturing.

scholarly journals Mechanical and Durability Properties of Fibre Reinforced Concrete made with OPC, GGBS and Metakaolin

2019 ◽  
Vol 8 (10) ◽  
pp. 3286-3290
Keyword(s):  
Reinforced Concrete ◽  
Fiber Reinforced Concrete ◽  
Industrial Wastes ◽  
Test Results ◽  
River Sand ◽  
Manufactured Sand ◽  
Durability Properties ◽  
Strength Tests ◽  
Massive Scale ◽  
Strength And Durability

Concrete is a globally utilized material in the construction field. In the last few decades, Concrete consumption has become multifold and usage has enhanced in massive scale due to the rapid growth of infra sector. Generally, Concrete consists of cement, aggregate, and water; these ingredients become more expensive day by day and additionally hard to please and is increasing widely. During the process of making Ordinary Portland Cement(OPC) produces a large amount of greenhouse gases and the environment being polluted. To minimize the cement utilization and environmental issues is essential to switch the cement by another alternate materials such as pozzolanas. The various number of pozzolanic materials comes from industrial wastes are Groundz Granulatedz Blastz furnacez Slagz (GGBS), xFlyqAsh (FA), zSilicazFume (SF), Metakaolin (MK) etc are utilized in concrete. Similarly, the availability of river sand is getting drained furthermore it turns out troublesome. In order to avoid this problem river sand is alter by zManufacturedkSand (M Sand). An attempt is made in the present investigation to study on properties of fiber reinforced concrete (qsteelu fibers @ 1% of binder) of M40 grade made with OPC, GGBS, MK and manufactured sand. In this study, OPC is replaced by GGBS and MK in different proportions. By casting requisite number of cubes, cylinders then zMechanical properties are determined such as fCompressivekstrength,sSplitdtensile strength tests and durability properties are determined by conducting Water absorption and Sorptivity tests. Test results are compared between controlled concrete and innovative concrete of M40 grade.It is observed that 30%(15%GGBS,15%MK) replacement is optimum for strength and durability criteria.

Friction Stir-Welded Titanium Alloy Ti-6Al-4V: Microstructure, Mechanical and Fracture Properties

JOM ◽  
2015 ◽  
Vol 67 (5) ◽  
pp. 1054-1063 ◽  
Author(s):  
D. G. Sanders ◽  
P. Edwards ◽  
A. M. Cantrell ◽  
K. Gangwar ◽  
M. Ramulu
Keyword(s):  
Titanium Alloy ◽  
Fracture Properties ◽  
Friction Stir ◽  
Mechanical And Fracture Properties
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