scholarly journals Irregular and suppressed elastic deformation by a structural twist in cellulose nanofibre models

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kojiro Uetani ◽  
Takuya Uto ◽  
Nozomu Suzuki
Keyword(s):  
Tensile Load ◽  
Functional Materials ◽  
Biological Tissues ◽  
Bending Stress ◽  
Deformation Response ◽  
Cellulose Nanofibres ◽  
Curvilinear Coordinate ◽  
Dimensional Parameters ◽  
Advanced Analysis ◽  
Orthotropic Properties

AbstractThe elastic responsiveness of single cellulose nanofibres is important for advanced analysis of biological tissues and their use in sophisticated functional materials. However, the mechanical responsiveness derived from the twisted structure of cellulose nanofibres (CNFs) has remained unexplored. In this study, finite element simulations were applied to characterize the deformation response derived from the torsional structure by performing tensile and bending tests of an unconventionally very long and twisted rod model, having the known dimensional parameters and properties of CNFs. The antagonistic action of two types of structural elements (a contour twist and a curvilinear coordinate) was found to result in an irregular deformation response but with only small fluctuations. The contour twist generated rotational displacements under tensile load, but the curvilinear coordinate suppressed rotational displacement. Under bending stress, the contour twist minimized irregular bending deformation because of the orthotropic properties and made the bending stress transferability a highly linear response.

scholarly journals Microstructural Characterization and Mechanical Behavior of NiTi Shape Memory Alloys Ultrasonic Joints Using Cu Interlayer

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1830 ◽  
Author(s):  
Wei Zhang ◽  
Sansan Ao ◽  
Joao Oliveira ◽  
Zhi Zeng ◽  
Yifei Huang ◽  
...  
Keyword(s):  
Shape Memory Alloys ◽  
Mechanical Behavior ◽  
Shape Memory ◽  
Energy Levels ◽  
Tensile Load ◽  
Functional Materials ◽  
Microstructural Characterization ◽  
Fusion Welding ◽  
Niti Shape Memory Alloys ◽  
Cu Interlayer

NiTi shape memory alloys (SMAs) are a class of functional materials which can be significantly deformed and recover their original shape via a reversible martensitic phase transformation. Developing effective joining techniques can expand the application of SMAs in the medical and engineering fields. In this study, ultrasonic spot welding (USW), a solid-state joining technique, was used to join NiTi sheets using a Cu interlayer in between the two joining sheets. The influence of USW process on the microstructural characteristics and mechanical behavior of the NiTi joints was investigated. Compared with conventional fusion welding techniques, no intermetallic compounds formed in the joints, which is extreme importance for this particular class of alloys. The joining mechanisms involve a combination of shear plastic deformation, mechanical interlocking and formation of micro-welds. A better bonding interface was obtained with higher welding energy levels, which contributed to a higher tensile load. An interfacial fracture mode occurred and the fracture surfaces exhibited both brittle and ductile-like characteristics with the existence of tear ridges and dimples. The fracture initiated at the weak region of the joint border and then propagated through it, leading to tearing of Cu foil at the fracture interface.

C(t) Estimation of Cracked Pipe Under Radial Thermal Gradient or Axial Displacement Control Load

2016 ◽  
Author(s):  
Jin-Ho Je ◽  
Kuk-Hee Lee ◽  
Yun-Jae Kim ◽  
Young-Ryun Oh
Keyword(s):  
Thermal Gradient ◽  
Radial Direction ◽  
Tensile Load ◽  
Bending Stress ◽  
Uniform Stress ◽  
Displacement Control ◽  
Element Analysis ◽  
Axial Tensile ◽  
Control Load

The present study analyzes the elastic follow-up factor under various secondary loads in the piping with cracks through finite element analysis. The secondary loads being considered included axial tensile load caused by the displacement applied in form of uniform stress through thickness and the load due to the thermal gradient in the radial direction applied as bending stress. According to this study, under displacement control loads, elastic follow-up factor can increase greatly.

scholarly journals Advanced analysis of nanoparticle composites – a means toward increasing the efficiency of functional materials

RSC Advances ◽  
2015 ◽  
Vol 5 (66) ◽  
pp. 53789-53795 ◽  
Author(s):  
C. R. Crick ◽  
S. Noimark ◽  
William J. Peveler ◽  
J. C. Bear ◽  
A. P. Ivanov ◽  
...  
Keyword(s):  
Functional Materials ◽  
Host Matrix ◽  
Advanced Analysis ◽  
Embedded Nanoparticles ◽  
Nanoparticle Composites

Direct visualisation of embedded nanoparticles allows for quantification of their concentration, at the surface and the bulk of host matrix.

Measurements of Magnetic Properties of Fe-Mn-Cr-Si-Sm-B Ferromagnetic Shape Memory Ribbons Depending on Stress and Temperature

2010 ◽  
Vol 670 ◽  
pp. 122-130
Author(s):  
Takashi Todaka ◽  
D. Yamamichi ◽  
Masato Enokizono
Keyword(s):  
Magnetic Properties ◽  
Shape Memory ◽  
Melt Spinning ◽  
Tensile Load ◽  
Functional Materials ◽  
Magnetic Sensors ◽  
Sensors And Actuators ◽  
Ferromagnetic Property ◽  
Shape Memory Property ◽  
Ferromagnetic Shape Memory

This paper presents measured magnetic and shape memory properties of Fe-Mn-Cr-Si-Sm-B ferromagnetic shape memory ribbons depending on tensile stress and temperature. The samples were produced with the melt spinning method in air and the magnetic properties were measured with an open solenoid type measurement system under controlling their temperature and tensile load. The alloys are multi-functional materials, which have both the ferromagnetic property and shape memory property. The measured results show applicability of the produced ribbon in applications for magnetic sensors and actuators.

scholarly journals ROLE OF FLUID ON THE CONTACT DEFORMATION RESPONSE OF BIOLOGICAL TISSUE

2020 ◽  
Vol 27 ◽  
pp. 22-31
Author(s):  
Michael V. Swain
Keyword(s):  
Soft Tissues ◽  
Mechanical Response ◽  
Critical Role ◽  
Biological Tissues ◽  
Complex Situation ◽  
Indentation Force ◽  
Deformation Response ◽  
Eye Tissues ◽  
Force Displacement

This paper will focus on the role of fluids on the indentation deformation response of tooth and eye tissues. All natural biological materials contain fluid and function in a fluidic environment, which plays a critical role in responding to loading events as well as tissue nutrition. The location of this fluid varies and is considered as both bound and mobile with much of it located in cell compartments that are also able to respond directly to loading. The extent of the fluid content varies from less than 10 % in the case of the highly mineralised enamel to more than 80 % in the case of soft eye tissues. The role of the fluid and its response during loading is also complicated by the hierarchical structure of biological tissues, be they mineralised or not. The mechanisms by which the presence of fluid in these materials influences the mechanical response is still poorly understood and has not been systematically investigated. The present paper presents data generated over many years on both the above biological tissues and attempts to present indications as to the mechanism(s) by which the presence of fluid contributes to the deformation. The situation associated with contact loading with the presence of mobile fluid in the tissues results in a more complex situation than the classic elastic-plastic contact situation, but the latter still forms the basis for much of the analysis of instrumented indentation force-displacement load-unloading curves using various shapes of indenters, especially for mineralised structures. In the case of soft tissues the absence of agreed protocols for interpretation of force-displacement-time responses is restricting clinical/biological applications.

Three-Dimensional Visualization of the T-System of Frog Muscle Using High Voltage Electron Microscopy and a Lanthanum Stain

1977 ◽  
Vol 35 ◽  
pp. 570-571 ◽  
Author(s):  
Lee D. Peachey ◽  
Clara Franzini-Armstrong
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Three Dimensional ◽  
Biological Tissues ◽  
High Voltage Electron Microscopy ◽  
Transverse Tubular System ◽  
Peroxidase Reaction ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
T System

The effective study of biological tissues in thick slices of embedded material by high voltage electron microscopy (HVEM) requires highly selective staining of those structures to be visualized so that they are not hidden or obscured by other structures in the image. A tilt pair of micrographs with subsequent stereoscopic viewing can be an important aid in three-dimensional visualization of these images, once an appropriate stain has been found. The peroxidase reaction has been used for this purpose in visualizing the T-system (transverse tubular system) of frog skeletal muscle by HVEM (1). We have found infiltration with lanthanum hydroxide to be particularly useful for three-dimensional visualization of certain aspects of the structure of the T- system in skeletal muscles of the frog. Specifically, lanthanum more completely fills the lumen of the tubules and is denser than the peroxidase reaction product.

On the High Voltage Electron Microscopy (1 MeV) of Biological Thick Sections

1972 ◽  
Vol 30 ◽  
pp. 464-465
Author(s):  
William H. Massover
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Present Report ◽  
Biological Tissues ◽  
Specimen Preparation ◽  
Technical Problems ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
Voltage Electron ◽  
High Voltage Electron

Stereoscopic examination of thick sections of fixed and embedded biological tissues by high voltage electron microscopy has been shown to allow direct visualization of three-dimensional fine structure. The present report will consider the occurrence of some new technical problems in specimen preparation and Image interpretation that are not common during lower voltage studies of thin sections.Thick Sectioning and Tissue Coloration - Epon sections of 0.5 μm or more that are cut with glass knives do not have a uniform thickness as Judged by their interference colors; these colors change with time during their flotation on the knife bath, and again when drying onto the specimen support. Quoted thicknesses thus must be considered only as rough estimates unless measured in specific regions by other methods. Chloroform vapors do not always result in good spreading of thick sections; however, they will spread spontaneously to large degrees after resting on the flotation bath for several minutes. Ribbons of thick sections have been almost impossible to obtain.

Rapid Critical Point Drying of Tissues in a Parr Bomb

1972 ◽  
Vol 30 ◽  
pp. 400-401
Author(s):  
C.A. Baechler ◽  
W. C. Pitchford ◽  
J. M. Riddle ◽  
C.B. Boyd ◽  
H. Kanagawa ◽  
...  
Keyword(s):  
Critical Point ◽  
Critical Pressure ◽  
Soft Tissues ◽  
Biological Tissues ◽  
Critical Temperatures ◽  
Air Drying ◽  
The Past ◽  
Critical Point Drying ◽  
Great Stress ◽  
Infiltration Techniques

Preservation of the topographic ultrastructure of soft biological tissues for examination by scanning electron microscopy has been accomplished in the past by using lengthy epoxy infiltration techniques, or dehydration in ethanol or acetone followed by air drying. Since the former technique requires several days of preparation and the latter technique subjects the tissues to great stress during the phase change encountered during air-drying, an alternate rapid, economical, and reliable method of surface structure preservation was developed. Turnbill and Philpott had used a fluorocarbon for the critical point drying of soft tissues and indicated the advantages of working with fluids having both moderately low critical pressures as well as low critical temperatures. Freon-116 (duPont) which has a critical temperature of 19. 7 C and a critical pressure of 432 psi was used in this study.

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