scholarly journals Physical Mechanical Properties and Producing Areas of Greek Dimension Stones

2021 ◽  
Vol 5 (1) ◽  
pp. 64
Author(s):  
Konstantinos Laskaridis ◽  
Angeliki Arapakou ◽  
Michael Patronis ◽  
Ioannis Kouseris
Keyword(s):  
Mechanical Properties ◽  
Current Status ◽  
Ornamental Stone ◽  
Ancient Times ◽  
Marble Industry

The most important Greek ornamental stone types are marbles, limestones, schists, slates, travertines and sandstones. Since ancient times, quarryinghas been connected to history and civilisation, i.e., the white “Pentelikon” marble being famous for the construction of Parthenon (Acropolis). Greek marble industry is a dynamic sector, among the top world producers of dimension stones, concerning both the volume of production and exports. This paper describes the current status of the major ornamental stone producing areas in Greece and presents typical average values of physical mechanical properties of the extracted stones, determined in LITHOS laboratory.

scholarly journals Dental Applications of Carbon Nanotubes

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4423
Author(s):  
Marco A. Castro-Rojas ◽  
Yadira I. Vega-Cantu ◽  
Geoffrey A. Cordell ◽  
Aida Rodriguez-Garcia
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Oral Cavity ◽  
Current Status ◽  
Glass Ionomer ◽  
Oral Infections ◽  
Functional Behavior ◽  
The Status ◽  
Comprehensive Survey ◽  
Dental Applications

Glass ionomer cements and resin-based composites are promising materials in restorative dentistry. However, their limited mechanical properties and the risk of bulk/marginal fracture compromise their lifespan. Intensive research has been conducted to understand and develop new materials that can mimic the functional behavior of the oral cavity. Nanotechnological approaches have emerged to treat oral infections and become a part of scaffolds for tissue regeneration. Carbon nanotubes are promising materials to create multifunctional platforms for dental applications. This review provides a comprehensive survey of and information on the status of this state-of-the-art technology and describes the development of glass ionomers reinforced with carbon nanotubes possessing improved mechanical properties. The applications of carbon nanotubes in drug delivery and tissue engineering for healing infections and lesions of the oral cavity are also described. The review concludes with a summary of the current status and presents a vision of future applications of carbon nanotubes in the practice of dentistry.

Determination of Cellular Mechanical Properties by Cell Poking, With an Application to Leukocytes

1990 ◽  
Vol 112 (3) ◽  
pp. 283-294 ◽  
Author(s):  
G. I. Zahalak ◽  
W. B. McConnaughey ◽  
E. L. Elson
Keyword(s):  
Mechanical Properties ◽  
Final Section ◽  
Mechanical Response ◽  
Living Cells ◽  
Micropipette Aspiration ◽  
Current Status ◽  
Technical Description ◽  
Analytical Results ◽  
Simple Models

In this paper we review the cell-poking technique as an approach for investigating the mechanical properties of living cells. We first summarize the rationale for the technique and the mainly qualitative results obtained so far. Then we provide a technical description of the instrument as it is configured at present. This is followed by a discussion of the current status of analytical results available for interpreting cell-poking measurements. In the final section we apply these results to an analysis of unmodulated and modulated lymphocytes and neutrophils, and conclude that the mechanical response of these leukocytes to indentation is not consistent with simple models developed by previous investigators on the basis of micropipette-aspiration experiments.

scholarly journals Porcelain enamel coatings, from the past to the future: solved and unsolved issues for the improvement of their mechanical properties.

2020 ◽  
Author(s):  
Stefano Rossi ◽  
Francesca Russo
Keyword(s):  
Mechanical Properties ◽  
Industrial Revolution ◽  
Chemical Degradation ◽  
Protective Properties ◽  
The Past ◽  
Enhanced Resistance ◽  
Mechanical Study ◽  
The Future ◽  
Ancient Times

Porcelain enamel coatings have their origins in ancient times when they were mainly used for decorative and ornamental purposes. From the industrial revolution onwards, these coatings have started to be used also as functional layers, ranging from home applications up to the use in high-technological fields, such as in chemical reactors. The excellent properties of enamel coatings, such as fire resistance, protection of the substrate from corrosion, resistance to atmospheric and chemical degradation, mainly depend and originate from the glassy nature of the enamel matrix itself. On the other side, the vitreous nature of enamel coatings limits their application in many fields, where mechanical stress and heavy abrasion phenomena could lead to nucleation and propagation of cracks inside the material, thus negatively affecting the protective properties of this coating. Many efforts have been made to improve the abrasion resistance of enamelled materials. On this regard, researchers showed encouraging results and proposed many different improvement approaches. Now it is possible to obtain enamels with enhanced resistance to abrasion. Differently, the investigation of the mechanical properties of enamel coatings remains a poorly studied topic. In the literature, there are interesting methodological ideas, which could be successfully applied to the mechanical study of enamelled materials and could allow to have further insights on their behaviour. Thus, the path that should be followed in the future includes the mechanical characterization of these coatings and the search for new solutions to address their brittle behaviour.

scholarly journals Role of Piezoelectric Elements in Finding the Mechanical Properties of Solid Industrial Materials

2018 ◽  
Vol 8 (10) ◽  
pp. 1737 ◽  
Author(s):  
Arshed Mohammed ◽  
Sallehuddin Haris ◽  
Mohd Nuawi
Keyword(s):  
Mechanical Properties ◽  
State Of The Art ◽  
New Technology ◽  
Material Testing ◽  
Current Status ◽  
Piezoelectric Elements ◽  
Need To Evaluate ◽  
Recent Developments ◽  
The Many

Recent developments in ultrasonic material testing have increased the need to evaluate the current status of the different applications of piezoelectric elements (PEs). This research have reviewed state-of-the-art emerging new technology and the role of PEs in tests for a number of mechanical properties, such as creep, fracture toughness, hardness, and impact toughness, among others. In this field, importance is given to the following variables, namely, (a) values of the natural frequency to PEs, (b) type and dimensions of specimens, and (c) purpose of the tests. All these variables are listed in three tables to illustrate the nature of their differences in these kinds of tests. Furthermore, recent achievements in this field are emphasized in addition to the many important studies that highlight the role of PEs.

scholarly journals Graphene-Based Films: Fabrication, Interfacial Modification, and Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2539
Author(s):  
Sihua Guo ◽  
Jin Chen ◽  
Yong Zhang ◽  
Johan Liu
Keyword(s):  
Mechanical Properties ◽  
Graphene Film ◽  
Current Status ◽  
Mechanical And Thermal Properties ◽  
Coating Technology ◽  
New Class ◽  
Interfacial Modification ◽  
Challenges And Opportunities ◽  
Potential Applications ◽  
Preparation Strategy

Graphene-based film attracts tremendous interest in many potential applications due to its excellent thermal, electrical, and mechanical properties. This review focused on a critical analysis of fabrication, processing methodology, the interfacial modification approach, and the applications of this novel and new class material. Strong attention was paid to the preparation strategy and interfacial modification approach to improve its mechanical and thermal properties. The overview also discussed the challenges and opportunities regarding its industrial production and the current status of the commercialization. This review showed that blade coating technology is an effective method for industrial mass-produced graphene film with controllable thickness. The synergistic effect of different interface interactions can effectively improve the mechanical properties of graphene-based film. At present, the application of graphene-based film on mobile phones has become an interesting example of the use of graphene. Looking for more application cases is of great significance for the development of graphene-based technology.

scholarly journals Artificial Thermal Decay: Influence of Mineralogy and Microstructure of Sandstone, Calcarenite and Marble

2021 ◽  
Vol 906 (1) ◽  
pp. 012123
Author(s):  
Andrea Aquino ◽  
Stefano Pagnotta ◽  
Marco Lezzerini
Keyword(s):  
Mechanical Properties ◽  
Thermal Stresses ◽  
Construction Materials ◽  
Physical And Mechanical Properties ◽  
Thermal Decay ◽  
Ornamental Stone ◽  
Aesthetic Appearance ◽  
Ornamental Stones ◽  
Before And After ◽  
Volume Measurements

Abstract Within a major framework of studies around artificial weathering and its effects on different lithotypes, in this work we study the effects of thermal stresses after artificial thermal decay on different types of stones used in historical buildings: a sandstone, a calcarenite and a marble. The sandstone belongs to the so called “Macigno” Formation and mainly outcrops along the northern Apennine (North Western Tuscany) and it has been widely used around Tuscany for building purposes (e.g., in Florence, Lucca, Pisa, Pistoia, etc.); the analysed calcarenite (Gravina) comes from the surrounding of Matera Town and has been deeply used for the construction of the ancient buildings of the town itself; and the marble comes from the Carrara marble district (Northern Tuscany), a highly used stone throughout the centuries as ornamental stone. All these types of stone for their physical and mechanical properties, and aesthetic appearance, have been extensively used as both ornamental stones and as construction materials. To reproduce a plausible effect of natural thermal decay of the stones due to day-to-night and season-to-season fluctuations, we subjected the samples to artificial thermal decay. We carried out different thermal cycles on the samples by using a stove at 150°C and a muffle furnace at 300°C and 450°C. We analysed the physical and mechanical properties before and after each cycle to compare and evaluate the effects of thermal stresses on the stones. Among the different analyses: mass and volume measurements, water absorption tests, mercury intrusion porosimetry, thin-section observations and determination of chromatic alterations through image analysis and Munsell charts method. It was then possible to evaluate the influence of both mineralogy and microstructures on thermal decay of the studied stones (variations in fabric and modifications on physical and mechanical properties).

Automotive Brake Disc Materials

2021 ◽  
Author(s):  
Costel FLOREA ◽  
Costica BEJINARIU ◽  
Nicanor CIMPOESU ◽  
Ramona CIMPOESU
Keyword(s):  
Mechanical Properties ◽  
Material Characterization ◽  
Current Status ◽  
Brake Disc ◽  
Friction Materials ◽  
Automotive Brake

The book reviews the current status of vehicle brake disc materials and technology. Topics covered include friction materials for braking systems, material characterization, mechanical properties, corrosion processes and methods for disc break investigations. The book references 158 original resources with their direct web links for in-depth reading.

scholarly journals Combined Effects of Chopped Carbon and Glass Fibres on Mechanical Properties of Lime-Based Mortar

2017 ◽  
Vol 26 (2) ◽  
pp. 096369351702600
Author(s):  
Burcin S. Seker ◽  
Ferit Cakir ◽  
Volkan Acar ◽  
Mehmet O. Seydibeyoglu ◽  
Hamit Akbulut
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Combined Effects ◽  
High Definition ◽  
Hydraulic Lime ◽  
Glass Fibres ◽  
Inorganic Substances ◽  
Third Stage ◽  
Ancient Times ◽  
Stage Scanning

Lime-based mortars have been used as bonding materials between stones or bricks since ancient times. It is an integral part of many structures and generally is used to fill the gaps between construction blocks (mortar joint) and strengthen the structures. Nowadays, different organic and inorganic substances are added to mortars in order to improve their physical and mechanical properties. This study deals with the combined effects of chopped carbon and glass fibres on mechanical properties of hydraulic lime-based mortar. Accordingly, lime-based mortar is prepared and chopped carbon (CCF) and glass (CGF) fibres are used as reinforcing materials in the lime-based mortar (1% by plain mortar weight). Five different combinations are investigated: Mixture-1 (100% CCF + 0% CGF), Mixture-2 (75% CCF + 25% CGF), Mixture-3 (50% CCF + 50% CGF), Mixture-4 (25% CCF + 75% CGF), Mixture-5 (0% CCF + 100% CGF). After reinforcing process, mechanical characterization tests are conducted on the mixtures at the end of 28 days curing. In the second stage, scanning electron microscope (SEM) observations and high definition visual inspection are carried out in order to investigate the interface mechanism between fibres and mortar. In the third stage, one-way analysis of variance (ANOVA) is performed to see whether differences between mechanical properties are statistically significant.

scholarly journals Examination of the Properties of Historical Wrought Iron in Architectural Structures

2018 ◽  
Author(s):  
István Vidovszky ◽  
Jenő Kiss
Keyword(s):  
Mechanical Properties ◽  
Vertical Component ◽  
Structural Elements ◽  
Modern Times ◽  
Wrought Iron ◽  
Reinforced Concrete Slabs ◽  
Hardness Tests ◽  
Ancient Times ◽  
Architectural Structures ◽  
Structural Connection

Wrought iron elements were produced of material with various quality from the ancient times to the early 20th century however played increasingly enhanced roles in the structural stability of buildings up to the modern times when reinforced concrete slabs and ring beams appeared. Wall ties and anchors were responsible for establishing a structural connection between slabs (beams) and walls or in case of vaults, such ties balanced the vertical component of the loads. There were some analyses in the literature on the strength of wrought iron structural elements, mainly bridge elements, manufactured in ironworks. However, there are a few studies only on the mechanical properties of the material of structures, which were manufactured manually in workshops that was typical in case of smaller construction elements. In this study, two types of hardness tests and tensile strength examinations were carried out on wrought iron structural elements taken from Hungarian buildings originating from the 18th, 19th and early 20th centuries to study the mechanical properties. Additionally, X-ray tests were performed to explore some features of manufacturing for the better understanding of the measured values. As a result, some information was gained about the structural analyses of the manually forged wrought iron elements.

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