scholarly journals Atomistic insights into the anisotropic mechanical properties and role of ripples on the thermal expansion of h-BCN monolayers

RSC Advances ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 1238-1246 ◽  
Author(s):  
Siby Thomas ◽  
Sang Uck Lee
Keyword(s):  
Mechanical Properties ◽  
Thermal Expansion ◽  
Composite Materials ◽  
Mechanical Stability ◽  
Conducting Material ◽  
Anisotropic Mechanical Properties

2D h-BCN is a novel planar semi-conducting material akin to graphene and h-BN with high thermal mechanical stability suitable for the design of h-BCN-based composite materials.

scholarly journals Maize brace root biomechanics are determined by geometry within a genotype and material properties between genotypes

2019 ◽  
Author(s):  
Lindsay Erndwein ◽  
Elahe Ganji ◽  
Ashley N. Hostetler ◽  
Adam Stager ◽  
Megan L. Killian ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Zea Mays ◽  
Material Properties ◽  
Growth Stage ◽  
Yield Loss ◽  
Mechanical Stability ◽  
Bending Tests ◽  
Bending Modulus ◽  
Root Biomechanics

ABSTRACTCrop plants are susceptible to yield loss by mechanical failure, which is called lodging. In maize (Zea mays), aerial nodal brace roots impart mechanical stability to plants, with previous studies showing that the lowest whorl of brace roots contributes the most. The features of brace roots that determine their contribution to mechanical stability are poorly defined. Here we tested the hypothesis that brace root mechanical properties vary between whorls, which may influence their contribution to mechanical stability. 3-point bending tests were used to determine that brace roots from the lowest whorl have the highest structural mechanical properties regardless of growth stage, and that these differences are largely due to brace root geometry within a genotype. Analysis of the brace root bending modulus determined that differences between genotypes are attributable to both geometry and material properties. These results support the role of brace root biomechanics to determine the brace root contribution to mechanical stability.HIGHLIGHTBrace root biomechanics vary within and between genotypes. These results support the importance of biomechanics to define the contribution of brace roots to mechanical stability.

THE ROLE OF THE SCALE FACTOR IN ESTIMATION OF THE MECHANICAL PROPERTIES OF COMPOSITE MATERIALS WITH NANOFILLERS

2010 ◽  
Vol 1 (3) ◽  
pp. 187-210 ◽  
Author(s):  
Yuri G. Yanovsky ◽  
Kh. Kh. Valiev ◽  
Yu. V. Kornev ◽  
Yu. N. Karnet ◽  
O. V. Boiko ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Scale Factor

Role of the crystallographic texture in anisotropic mechanical properties of a newly-developed hot-rolled TRIP steel

2020 ◽  
Vol 790 ◽  
pp. 139683
Author(s):  
Shih-Che Chen ◽  
Cheng-Yao Huang ◽  
Yuan-Tsung Wang ◽  
Ching-Yuan Huang ◽  
Hung-Wei Yen
Keyword(s):  
Mechanical Properties ◽  
Crystallographic Texture ◽  
Trip Steel ◽  
Anisotropic Mechanical Properties ◽  
Hot Rolled

scholarly journals The structural role of bacterial eDNA in the formation of biofilm streamers

2021 ◽  
Author(s):  
Eleonora Secchi ◽  
Giovanni Savorana ◽  
Alessandra Vitale ◽  
Leo Eberl ◽  
Roman Stocker ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Extracellular Polymeric Substances ◽  
Bacterial Resistance ◽  
Mechanical Stability ◽  
Antimicrobial Treatment ◽  
Geometric Constraints ◽  
Extracellular Dna ◽  
Clinical Settings ◽  
Biofilm Matrix

Across diverse habitats, bacteria are mainly found as biofilms, surface-attached communities embedded in a self-secreted matrix of extracellular polymeric substances (EPS), which enhances bacterial resistance to antimicrobial treatment and mechanical stresses. In the presence of flow and geometric constraints such as corners or constrictions, biofilms take the form of long, suspended threads known as streamers, which bear important consequences in industrial and clinical settings by causing clogging and fouling. The formation of streamers is thought to be driven by the viscoelastic nature of the biofilm matrix. Yet, little is known about the structural composition of streamers and how it affects their mechanical properties. Here, using a microfluidic platform that allows growing and precisely examining biofilm streamers, we show that extracellular DNA (eDNA) constitutes the backbone and is essential for the mechanical stability of Pseudomonas aeruginosa' s streamers. This finding is supported by the observations that DNA-degrading enzymes prevent the formation of streamers and clear already formed ones, and that the antibiotic ciprofloxacin promotes their formation by increasing the release of eDNA. Furthermore, using mutants for production of the exopolysaccharide Pel, an important component of P. aeruginosa' s EPS, we reveal a new, although indirect role of Pel, in tuning the mechanical properties of the streamers. Taken together, these results highlight the importance of eDNA and of its interplay with Pel in determining the mechanical properties of P. aeruginosa streamers, and suggest that targeting the composition of streamers can be an effective approach to control the formation of these biofilm structures.

scholarly journals Aging of Polymer Composites in Extremely Cold Climates

2020 ◽  
pp. 41-51 ◽  
Author(s):  
O.V. Startsev ◽  
M. P. Lebedev ◽  
A.K. Kychkin
Keyword(s):  
Mechanical Properties ◽  
Thermal Expansion ◽  
Composite Materials ◽  
Solar Radiation ◽  
Solid Phase ◽  
Climatic Conditions ◽  
Internal Stresses ◽  
Cold Climates ◽  
Reinforcing Fibers ◽  
Effects Of Temperature

A review of studies of effects of temperature, moisture, solar radiation, and other aggressive environmental factors on the properties of polymer composite materials are presented to substantiate the mechanism of their aging in extremely cold climates. It has been shown that composites develop internal stresses caused by unequal thermal expansion of reinforcing fibers and polymer matrices. These internal stresses cause the occurrence of microcracks, their coalescence, and formation of macro-damages in the bulk of the binder or at the interface with fibers. Fiberglass, carbon fiber, and other reinforced materials exposed to climatic conditions can accumulate water in pores and capillaries, which can turn into a solid phase at temperatures below 0 °C and increase internal stresses. Even in cold climates, the surface of materials undergoes destruction and microcracking under the impacts of UV components of solar radiation, thus increasing the number of sources of internal stresses. The mechanical properties of composite materials deteriorate under the effects of seasonal and daily thermal cycles.

Study on the Relationship between the Bonding Surface and Mechanical Properties of PLA/Epoxy Laminated Composites

2021 ◽  
Vol 36 (4) ◽  
pp. 410-416
Author(s):  
C. Li ◽  
X.-J. Shi ◽  
X.-H. Tuo ◽  
Y.-M. Gong ◽  
J. Guo
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Structural Design ◽  
Mechanical Performance ◽  
Laminated Composite ◽  
Reference Information ◽  
Laminated Composite Materials ◽  
The Relationship ◽  
Bonding Surface

Abstract Rule of mixtures (RoMs) of composite materials is continuously modified according to different component materials and their composition forms to play the role of theoretical verification and evaluation. This paper studied the regular relationship between the bonding surface and mechanical performance of the composites. The three bonding surface designs were made into PLA/EP test samples by 3D printing technology. The tensile and bending properties of the composite materials were proved to be stronger than the average of those of their component materials. The mechanical properties show regular changes with the bonding surface and structural design. The bonding surface between components is an important reference information that cannot be ignored for the performance prediction and adjustment of laminated composite materials.

Rod-Textured Zircaloy-2: A Case Study of an Anisotropic Metal with Multiple Deformation Modes, Strong Texture and Thermal Strains

2008 ◽  
Vol 571-572 ◽  
pp. 77-82 ◽  
Author(s):  
Thomas Holden
Keyword(s):  
Mechanical Properties ◽  
Applied Stress ◽  
Prism Slip ◽  
Hexagonal Close Packed ◽  
Road Map ◽  
Anisotropic Mechanical Properties ◽  
Residual Strains ◽  
Multiple Deformation ◽  
Applied Stresses

Hexagonal close-packed and lower symmetry metals often exhibit anisotropic mechanical properties because the dominant slip system forbids slip in certain lattice directions. Rod-textured Zircaloy-2 is a model system which can act as a road map for understanding more complex cases. In this case prism slip is dominant and pyramidal slip is only initiated at higher applied stresses. Tensile twinning does not always play a role since its initiation depends on the starting texture. Along the rod axis, Zircaloy-2 exhibits a very strong weighting of poles lying within the basal plane of the structure such as <10 1 0>, <11 2 0> etc. However, perpendicular to the rod axis, all <hkil> poles are present. The coefficients of thermal expansion are unequal along the a- and c-axes of the crystal structure, so there are always large intrinsic thermal strains. Likewise, the mechanical properties perpendicular to the rod axis are dominated by the interaction of grains with hard and soft plastic response. Over two decades, the residual strains and the in-situ strain response parallel and perpendicular to the rod axis have been measured by neutron diffraction for both tensile and compressive applied stress. The paper reviews our understanding of the strain development for tensile and compressive applied stress in Zircaloy-2 in terms of slip and tensile twinning, the crucial part played by the thermal strains and the simplifying role of the strong texture.

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. 

Aging of polymer composite materials under loading. (See Beginning in #10-2020)

2020 ◽  
pp. 2-12
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Polymer Composite ◽  
Polymer Composite Materials ◽  
Cyclic Loads ◽  
Reinforced Plastics ◽  
Water Exposure ◽  
Laboratory Conditions ◽  
Bending Loads ◽  
Moisture Conditions

A study review of aging polymer composite materials (PCM) under different heat-moisture conditions or water exposure with the sequential or parallel influence of static or cyclic loads in laboratory conditions is presented. The influence of tension and bending loads is compared. Conditions of the different load influence on parameters of carbon-reinforced plastics and glass-reinforced plastics are discussed. Equipment and units for climatic tests of PCM under loading are described. Simulation examples of indices of mechanical properties of PCM under the influence of environment and loads are shown.

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