scholarly journals Longitudinal Tension and Mechanical Stability of a Pressurized Straw Tube

Instruments ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 27
Author(s):  
Levan Glonti ◽  
Temur Enik ◽  
Vladimir Kekelidze ◽  
Alexander Kolesnikov ◽  
Dmitry Madigozhin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Charged Particle ◽  
Measurement Technique ◽  
Mechanical Stability ◽  
Stability Conditions ◽  
Particle Detectors ◽  
Straw Tube ◽  
Special Measurement ◽  
The Stability ◽  
Tube Study

For the development of charged particle detectors based on straw tubes operating in vacuum, a special measurement technique is required for the evaluation of their mechanical properties. A summary of the known equations that govern straw behavior under internal pressure is provided, and a new experimental method of a strained pressurized straw tube study is presented in this paper. The Poisson’s ratio of the straw wall, which defines the stability conditions of a built-in tube, was measured for the NA62 spectrometer straw, and its minimum pre-tension was estimated.

An analysis of the transport properties and mechanical stability of rapidly solidified Al-Sb alloy

2015 ◽  
Vol 10 (2) ◽  
pp. 2663-2681
Author(s):  
Rizk El- Sayed ◽  
Mustafa Kamal ◽  
Abu-Bakr El-Bediwi ◽  
Qutaiba Rasheed Solaiman
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Melt Spinning ◽  
Elastic Moduli ◽  
Mechanical Stability ◽  
Microstructural Analysis ◽  
Alloy System ◽  
Antimony Content ◽  
The Stability ◽  
Rapidly Solidified

The structure of a series of AlSb alloys prepared by melt spinning have been studied in the as melt–spun ribbons  as a function of antimony content .The stability  of these structures has  been  related to that of the transport and mechanical properties of the alloy ribbons. Microstructural analysis was performed and it was found that only Al and AlSb phases formed for different composition.  The electrical, thermal and the stability of the mechanical properties are related indirectly through the influence of the antimony content. The results are interpreted in terms of the phase change occurring to alloy system. Electrical resistivity, thermal conductivity, elastic moduli and the values of microhardness are found to be more sensitive than the internal friction to the phase changes. 

scholarly journals New crosslinkers for electrospun chitosan fibre mats. I. Chemical analysis

2012 ◽  
Vol 9 (75) ◽  
pp. 2551-2562 ◽  
Author(s):  
Marjorie S. Austero ◽  
Amalie E. Donius ◽  
Ulrike G. K. Wegst ◽  
Caroline L. Schauer
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Mechanical Stability ◽  
Dissolution Tests ◽  
Natural Polysaccharide ◽  
Biomedical Field ◽  
The Stability ◽  
Scanning Electron

Chitosan (CS), the deacetylated form of chitin, the second most abundant, natural polysaccharide, is attractive for applications in the biomedical field because of its biocompatibility and resorption rates, which are higher than chitin. Crosslinking improves chemical and mechanical stability of CS. Here, we report the successful utilization of a new set of crosslinkers for electrospun CS. Genipin, hexamethylene-1,6-diaminocarboxysulphonate (HDACS) and epichlorohydrin (ECH) have not been previously explored for crosslinking of electrospun CS. In this first part of a two-part publication, we report the morphology, determined by field emission scanning electron microscopy (FESEM), and chemical interactions, determined by Fourier transform infrared microscopy, respectively. FESEM revealed that CS could successfully be electrospun from trifluoroacetic acid with genipin, HDACS and ECH added to the solution. Diameters were 267 ± 199 nm, 644 ± 359 nm and 896 ± 435 nm for CS–genipin, CS–HDACS and CS–ECH, respectively. Short- (15 min) and long-term (72 h) dissolution tests (T 600 ) were performed in acidic, neutral and basic pHs (3, 7 and 12). Post-spinning activation by heat and base to enhance crosslinking of CS–HDACS and CS–ECH decreased the fibre diameters and improved the stability. In the second part of this publication, we report the mechanical properties of the fibres.

scholarly journals Effect of Metallic Inclusions on the Compressive Strength of Cement-Based Materials

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Tomáš Ficker
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Mechanical Stability ◽  
Transition Zones ◽  
Metallic Inclusions ◽  
Cement Based Materials ◽  
Concrete Materials ◽  
Materials Used ◽  
The Stability ◽  
Critical Limits

In the concrete foundations, materials come into contact with bedrocks. The surfaces of bedrocks are often covered by sharp protrusions called asperities. Although geotechnical engineers have developed a reliable theory for assessing the mechanical stability of rocky terrains, the stability of transition zones between concrete and sharp asperities remains unsolved. Due to the large pressures that exist in these transition zones, the invasive influence of sharp asperities on the integrity of the concrete raises a question about possible changes of the mechanical properties of concrete materials used in foundations. These circumstances have inspired experiments in which metallic needles of various lengths have been embedded into cement-based materials to assess the influence of the needles on the compressive strength. This influence has been quantified, and the critical limits identifying the changes of material integrity have been determined. It has been conjectured that sharp rock asperities or needle-like rods of steel reinforcement in concrete may cause similar changes of material integrity as the metallic needles used in the experiments performed.

Microstructures and Mechanical Properties of Annealed Fe-8Mn-6Al-0.4C Duplex Low-Density Steels

2021 ◽  
Vol 1035 ◽  
pp. 337-343
Author(s):  
Rong Chen ◽  
Peng Chen ◽  
Xiao Wu Li
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Mechanical Stability ◽  
Volume Fraction ◽  
Electron Back Scatter Diffraction ◽  
Low Density ◽  
X Ray Diffraction ◽  
Austenite Grain Size ◽  
The Stability

The cold-rolled Fe-8Mn-6Al-0.4C duplex low-density steel was annealed at different conditions to obtain ferrite + austenite duplex microstructure. The excellent mechanical properties (i.e., elongation of 52%, tensile strength of 785 MPa, and a product of tensile strength and elongation of 40.9 GPa·%) have been obtained by adjusting the volume fraction and the stability of austenite. The microstructure of the experimental steels was analyzed by scanning electron microscopy (SEM) and electron back-scatter diffraction (EBSD), and the volume fraction of austenite was estimated by the X-ray diffraction (XRD). The results show that the distribution of austenite grain size is inhomogeneous, and that the mechanical stability of austenite is mainly affected by the alloying partitioning and the variation of grain size during the annealing process. The increase of elongation is attributed to the degradation in mechanical stability of austenite, which can efficiently promote an occurrence of transformation induced plasticity (TRIP) effect.

Improving the mechanical stability of proton conducting SPEEK membranes by in situ precipitation of zirconium phosphate phenylphosphonates

RSC Advances ◽  
2016 ◽  
Vol 6 (43) ◽  
pp. 36606-36614 ◽  
Author(s):  
Monica Pica ◽  
Roberto D'Amato ◽  
Anna Donnadio ◽  
Donatella Capitani ◽  
Elisabetta Troni ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Proton Conductivity ◽  
Zirconium Phosphate ◽  
Mechanical Stability ◽  
Proton Conducting ◽  
The Stability

Zirconium phosphate phenylphosphonate nanoparticles improve mechanical properties and the stability of the proton conductivity of composite SPEEK membranes.

scholarly journals Thermodynamic Stability Conditions as an Eigenvalues Fundamental Problem

2021 ◽  
Author(s):  
Francisco Nogueira Lima
Keyword(s):  
Thermodynamic Stability ◽  
Quadratic Forms ◽  
Mechanical Stability ◽  
Fundamental Problem ◽  
Physical Stability ◽  
Analytical Techniques ◽  
Stability Conditions ◽  
Mathematical Techniques ◽  
The Stability ◽  
Physical Laws

Quadratic forms diagonalization methods can be used in addressing the stability of physical systems. Thermodynamic stability conditions appears as an eigenvalues fundamental problem, in particular when postulational approaches is taken. The second-order derivatives or appropriate relations between such derivatives of the energy, entropy or any considered thermodynamic potential, as Helmholtz, enthalpy and Gibbs, have interesting mathematical features that directly imply in the physical stability, obtained by use and as consequence of analytical techniques. Formal aspects on the thermal and mechanical stability become simple consequences, but no less formal, of the superposition of rigorously established physical laws, and appropriate applications of mathematical techniques.

The Sintering Behaviour and Mechanical Properties of Hydroxyapatite - Based Composites for Bone Tissue Regeneration

2018 ◽  
Vol 69 (5) ◽  
pp. 1272-1275 ◽  
Author(s):  
Camelia Tecu ◽  
Aurora Antoniac ◽  
Gultekin Goller ◽  
Mustafa Guven Gok ◽  
Marius Manole ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tricalcium Phosphate ◽  
Cosmetic Surgery ◽  
Mechanical Stability ◽  
Raw Materials ◽  
Oyster Shell ◽  
Bone Tissue Regeneration ◽  
Sintering Behavior ◽  
Bovine Bone ◽  
Human Teeth

Bone reconstruction is a complex process which involves an osteoconductive matrix, osteoinductive signaling, osteogenic cells, vascularization and mechanical stability. Lately, to improve the healing of the bone defects and to accelerate the bone fusion and bone augmentation, bioceramic composite materials have been used as bone substitutes in the field of orthopedics and dentistry, as well as in cosmetic surgery. Of all types of bioceramics, the most used is hydroxyapatite, because of its similar properties to those of the human bone and better mechanical properties compared to b-tricalcium phosphate [1]. Currently, the most used raw materials sources for obtaining the hydroxyapatite are: bovine bone, seashells, corals, oyster shell, eggshells and human teeth. There are two common ways to obtain hydroxyapatite: synthetically and naturally. Generally, for the improvement of the mechanical properties and the structural one, hydroxyapatite is subjected to the sintering process. Considering the disadvantages of hydroxyapatite such as poor biodegradation rate, b-TCP has been developed, which has some disadvantages too, such as brittleness. For this reason, the aim of this study is to look into the effect of adding magnesium oxide on the sintering behavior, the structure and the mechanical properties of the hydroxyapatite-tricalcium phosphate composites.

Effect of the surface chemistry on the stability and mechanical properties of the Zirconia-Hydroxyapatite bioceramic

2021 ◽  
Vol 23 ◽  
pp. 100980
Author(s):  
M. Es-saddik ◽  
S. Laasri ◽  
M. Taha ◽  
A. Laghzizil ◽  
A. Guidara ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Chemistry ◽  
The Stability
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