scholarly journals New Insight into the Toughening Mechanisms of Seashell: From Arch Shape to Multilayer Structure

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Quan Yuan ◽  
Botao Chen ◽  
Bin Chen ◽  
Zeyun Wang
Keyword(s):  
Aspect Ratio ◽  
Multilayer Structure ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Structure Property ◽  
Soft Layer ◽  
Structure Property Relationships ◽  
Straight Beam ◽  
Overlap Ratio ◽  
Arch Shape

A seashell is a closed three-dimensional curved surface formed by two symmetrical open shells. Three-point bending is performed on a pure aragonite straight beam (PASB) model and a multilayer structure curved beam (MSCB) model to elucidate the structure-property relationships of seashells. The integrity of the PASB is broken because of the introduction of a soft layer, but this drawback is compensated by the peculiar arch shape and the internal multilayer structure. The effective modulus, stiffness, and fracture energy of MSCB increase with an increase in volume fraction, aspect ratio of aragonite platelet, overlap ratio of hard layers, and ratio of the elastic modulus of the hard layer to the shear modulus of the soft layer. New design disciplines drawn from the MSCB model are peculiar arch shape, internal multilayer structure of larger volume fraction, and aspect ratio of hard layers and nanoscaled soft layers.

Improving UV Resistance of Fibers: Idealized Computational Model Predicting the Distribution of UV Blocking Cylindrical Nanoparticles in Protective Polymeric Layer

2015 ◽  
Vol 10 (1) ◽  
pp. 155892501501000
Author(s):  
Abdelfattah Mohamed Seyam ◽  
Rahul Vallabh ◽  
Ahmed H. Hassanin
Keyword(s):  
Aspect Ratio ◽  
Computational Model ◽  
High Performance ◽  
Volume Fraction ◽  
Three Dimensional ◽  
High Strength ◽  
Uv Protection ◽  
Uv Resistance ◽  
Premature Failure ◽  
Areal Coverage

High strength fibers such as PBO and Kevlar are used to produce composites, bulletproof vests, tendons of giant scientific balloons, and other high performance products. These fibers, however, are known to degrade upon exposure to Ultraviolet (UV) radiation which causes premature failure of the end-products. Improving UV resistance of high strength fibers like PBO through methods such as adding UV inhibiting particles during filament spinning or dyeing/coating process is not only extremely difficult, but often fails to provide the adequate UV protection. As an alternative to conventional approaches, UV protection of high performance yarns/braids can be effectively achieved by covering them with a polymeric sheath containing dispersed UV inhibiting nanoparticles. In this work, a computational model was developed to optimize critical factors such as thickness (weight) of the protective sheath and the amount of UV blockers for a given particle size, which influence the UV protective efficiency of the sheath. In order to simulate three-dimensional dispersion of nanoparticles in a polymer matrix, the model considers a random distribution of cylindrical nanoparticles of different size, aspect ratio, and volume fraction in a three-dimensional volume of protective sheath of a given length, width, and thickness. 2D visualization and image analysis techniques were utilized to determine the area projected by the particles on the x-y plane (areal coverage provided by nanoparticles). The areal coverage values obtained from the model were found to be higher than the experimental results due to the agglomeration of nanoparticles in the sheath caused during the polymer compounding process. However, the purpose of the model is to serve as a benchmarking tool to aid in the design and development of UV protective sheaths and films, and not to estimate absolute UV protection values. Analysis of the relationship between areal coverage and various input parameters in the model show that areal coverage increases with an increase in particle volume fraction and film thickness, and a decrease in particle diameter and length. It was also found that areal coverage was more significantly influenced by particle aspect ratio than by particle length.

X-ray microtomographic imaging and analysis for basic research

2006 ◽  
Vol 21 (2) ◽  
pp. 125-131 ◽  
Author(s):  
J. H. Dunsmuir ◽  
S. Bennett ◽  
L. Fareria ◽  
A. Mingino ◽  
M. Sansone
Keyword(s):  
Spatial Resolution ◽  
Three Dimensional ◽  
Basic Research ◽  
Integrated Approach ◽  
Imaging Method ◽  
Structure Property ◽  
3D Images ◽  
X Ray ◽  
Structure Property Relationships ◽  
Essential Components

For research facilities with access to synchrotron X-ray sources, X-ray absorption microtomography (XMT) has evolved from an experimental imaging method to a specialized, if not yet routine, microscopy for imaging the three-dimensional (3D) distribution of linear attenuation coefficients and, in some cases, elemental concentration with micron spatial resolution. Recent advances in source and detector design have produced conventional X-ray source instruments with comparable spatial resolution but with lower throughput and without element specific imaging. Both classes of instrument produce 3D images for analysis. We discuss an integrated approach for the implementation of analytical XMT to support basic research into the structure-property relationships of a variety of materials. The essential components include instrumentation for collecting quantitative 3D images, a 3D image processing environment to address questions as to the quantity, composition, geometry, and relationships among the features in one or more images, and visualization to provide insight and communicate results. We give examples of image analysis of resolved and unresolved pore spaces of sandstones.

scholarly journals Multifractal investigation of Ag/DLC nanocomposite thin films

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ştefan Ţălu ◽  
Bandar Astinchap ◽  
Senour Abdolghaderi ◽  
Azizollah Shafiekhani ◽  
Ilya A. Morozov
Keyword(s):  
Graphical Representation ◽  
Three Dimensional ◽  
Rf Sputtering ◽  
Chemical Vapor ◽  
Structure Property ◽  
Force Microscopy ◽  
Additional Information ◽  
Structure Property Relationships ◽  
Surface Micromorphology ◽  
Novel Algorithms

AbstractThe objective of this study is the experimental investigation of the silver in diamond-like carbon (Ag/DLC) nanocomposite prepared by the co-deposition of radio frequency plasma-enhanced chemical vapor deposition (RF-PECVD) and RF-sputtering. Atomic force microscopy (AFM), X-ray diffraction analyses, ultraviolet–visible (UV–visible) spectroscopy measurements were applied to describe the three-dimensional surface texture data in connection with the statistical, and multifractal analyses. Additional information about structure–property relationships in prepared Ag/DLC nanocomposite was studied in detail to allow a better understanding of the surface micromorphology. The performed analysis revealed the studied samples have multifractal properties and can be included in novel algorithms for graphical representation of complex geometrical shapes and implemented in computer simulation algorithms.

Combined TEM/SEI of polymer membranes

1984 ◽  
Vol 42 ◽  
pp. 386-387
Author(s):  
L. C. Sawyer
Keyword(s):  
Three Dimensional ◽  
Polymer Membranes ◽  
Industrial Process ◽  
Polymeric Materials ◽  
Structure Property ◽  
Shape Distribution ◽  
Structure Property Relationships ◽  
Wide Range ◽  
Fundamental Understanding ◽  
Potential Applications

Structure-property relationships are important in the process optimization and fundamental understanding of many polymeric materials, including membranes. Polymer membranes are currently being used for separation, concentration or purification in a wide range of industrial process applications. The process used to manufacture the membrane, and the polymer type, determines the morphology, which influences the membrane transport properties and potential applications. The morphology includes: pore size, shape, distribution and their overall three dimensional arrangement. Microscopical methods are needed to image the structures formed by the various processes, in order to systematically study changes in variables for specific applications.

scholarly journals Modeling of Structure-Property Relationships of Polymerizable Surfactants with Antimicrobial Activity

2018 ◽  
Vol 8 (10) ◽  
pp. 1972 ◽  
Author(s):  
Giorgio De Luca ◽  
Roberta Amuso ◽  
Alberto Figoli ◽  
Raffaella Mancuso ◽  
Lucio Lucadamo ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Molecular Structures ◽  
Maximum Length ◽  
Aliphatic Chain ◽  
Structure Property ◽  
Net Charge ◽  
Structure Property Relationships ◽  
Electrostatic Charges ◽  
Partial Charges ◽  
The Relationship

Polymerizable quaternary ammonium salts (PQASs) were synthesized in a previous work and some of them were used as surfactants in the antimicrobial coating of commercial membranes. Herein, the electrostatic charges, maximum length, and aspect ratio of these antibacterial surfactants were calculated with the aim of investigating the relationship between the properties, recognized to control the biocidal activity of these molecules, and the molecular structures. The effect of the water molecules was considered through a quantum and molecular mechanics approach. The correlation between the number of carbons in the main aliphatic chain of PQAS and the above properties was investigated, by finding that the net charge on the ammonium group does not increase as the number of carbons in the aliphatic chain increase. Thus, although this number influences the antibacterial activity of the surfactants, this influence is not correlated with an increase of the ammonium positive charge. Unlike the partial charges, a different trend was obtained for the surfactants’ maximum length and aspect ratio in agreement with the experimental behavior. As this modeling does not use empirical or adjustable parameters, it can assist the synthetic plan of new structures for surface functionalization, in order to improve the biofouling resistance of the membranes.

3D Reconstruction of Microstructure for Centrifugal Casting Babbitt Lining of Bimetallic Bearing Based on Mimics

2020 ◽  
Vol 841 ◽  
pp. 94-98
Author(s):  
Qin Dong ◽  
Zhong Wei Yin ◽  
Hu Lin Li ◽  
Yang Mao ◽  
Geng Yuan Gao
Keyword(s):  
3D Reconstruction ◽  
Volume Fraction ◽  
Centrifugal Casting ◽  
Microstructural Characterization ◽  
Structure Property ◽  
Hard Phase ◽  
Comprehensive Understanding ◽  
Structure Property Relationships ◽  
Medical Software ◽  
Bearing Materials

Babbitt alloys are the most commonly used bearing materials for low speed diesel engines due to their excellent attributes. An understanding of microstructures in these alloys is important, especially quantifying microstructure in 3D. In this study, we used serial sectioning technique to reconstruct 3D microstructure of tin-based Babbitt lining of bimetallic bearing made by centrifugal casting based on medical software Mimics. The morphologies and volume fraction of hard phase particles and α-Sn matrix were obtained. The volume fraction of the reconstructed microstructures was verified by the area fraction of the metallographic sections, which proved a higher reliability of 3D reconstruction. The results of 3D microstructural characterization and analysis will enable a comprehensive understanding the structure–property relationships of these materials.

Structure–property relationships in lithium superionic conductors having a Li10GeP2S12-type structure

2015 ◽  
Vol 71 (6) ◽  
pp. 727-736 ◽  
Author(s):  
Satoshi Hori ◽  
Sou Taminato ◽  
Kota Suzuki ◽  
Masaaki Hirayama ◽  
Yuki Kato ◽  
...  
Keyword(s):  
Maximum Entropy Method ◽  
Ionic Conduction ◽  
Three Dimensional ◽  
Entropy Method ◽  
Type Structure ◽  
Superionic Conductors ◽  
Structural Parameter ◽  
Structure Property ◽  
Temperature Range ◽  
Structure Property Relationships

The crystal structures of the superionic conductors Li9.81Sn0.81P2.19S12 and Li10.35Si1.35P1.65S12, both having a Li10GeP2S12 (LGPS)-type structure, were determined by neutron diffraction analysis over the temperature range 12–800 K. The maximum entropy method was also employed to clarify the lithium distribution in these materials. The Sn system showed one-dimensional diffusion in the c direction over a wide temperature range, even though the Ge-based system typically exhibits three-dimensional conduction at higher temperatures. The ionic conduction mechanisms of analogous Si, Ge and Sn phases with LGPS-type structures are discussed on the basis of the observed structural parameter changes.

Investigating the impact of three-dimensional learning interventions on student understanding of structure–property relationships

2021 ◽  
Author(s):  
Sonia M. Underwood ◽  
Alex T. Kararo ◽  
Gabriela Gadia
Keyword(s):  
General Chemistry ◽  
Active Learning ◽  
Boiling Point ◽  
Three Dimensional ◽  
Intermolecular Forces ◽  
Control Group ◽  
Chemistry Curriculum ◽  
Structure Property ◽  
Structure Property Relationships ◽  
The Impact

The ability to predict macroscopic properties using a compound's chemical structure is an essential idea for chemistry as well as other disciplines such as biology. In this study we investigate how different levels of interventions impact the components of students’ explanations (claims, evidence, and reasoning) of structure–property relationships, particularly related to boiling point trends. These interventions, aligned with Three-Dimensional Learning (3DL), were investigated with four different cohorts of students: Cohort 1 – a control group of students enrolled in an active learning general chemistry course; Cohort 2 – students enrolled in the same active learning general chemistry course but given Intervention 1 (a 3DL worksheet administered during class time); Cohort 3 – students enrolled in the same active learning general chemistry course but given Intervention 1 and Intervention 2 (a 3DL course exam question administered after instruction); and Cohort 4 – a reference group of students enrolled in a transformed active learning general chemistry curriculum in which 3DL is an essential feature and includes Intervention 1 and Intervention 2 as part of the curriculum. We found that Cohort 2 students (with the 3DL worksheet intervention) were more likely than the control group (Cohort 1) to correctly predict the compound with a higher boiling point as well as incorporate ideas of strength of intermolecular forces into their explanations of boiling point differences. When a 3DL exam question was given as a follow up to the 3DL worksheet, students in Cohort 3 were more likely than Cohorts 1 and 2 to correctly identify the claim. Further comparison showed that Cohort 4 (transformed general chemistry curriculum) were more likely than Cohorts 1–3 to also include the ideas of energy needed to overcome stronger forces for a more sophisticated explanation (50% of Cohort 4 students compared to 17–33% for Cohorts 1–3). In addition, 80% of Cohort 4 students were able to construct a correct representation of hydrogen bonding as a non-covalent interaction compared to 13–57% for the other three cohorts.

Three-Dimensional Numerical Simulation of Random Fiber Composites With High Aspect Ratio and High Volume Fraction

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Bo Cheng Jin ◽  
Assimina A. Pelegri
Keyword(s):  
Aspect Ratio ◽  
Volume Fraction ◽  
Fiber Composite ◽  
Three Dimensional ◽  
High Volume ◽  
Fiber Composites ◽  
High Volume Fraction ◽  
Fiber Networks ◽  
Representative Volume ◽  
Representative Volume Elements

Organic and inorganic fiber reinforced composites with various fiber orientation distributions and fiber geometries are abundantly available in several natural and synthetic structures. Inorganic glass fiber composites have been introduced to numerous applications due to their economical fabrication and tailored structural properties. Numerical characterization of such composite materials is necessitated due to their intrinsic statistical nature, since elaborate experiments are prohibitively costly and time consuming. In this work, representative volume elements of unidirectional random filaments and fibers are numerically developed in PYTHON to enhance accuracy and efficiency of complex geometric representations encountered in random fiber networks. A modified random sequential adsorption algorithm is applied to increase the volume fraction of the representative volume elements, and a spatial segment shortest distance algorithm is introduced to construct a 3D random fiber composite with high fiber aspect ratio (100:1) and high volume fraction (31.8%). For the unidirectional fiber networks, volume fractions as high as 70% are achieved when an assortment of circular fiber diameters are used in the representative volume element.

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