scholarly journals The Influence of Pore Size and Material Properties on Biomechanical Analysis of Parietal-Temporal Implant

Evergreen ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 750-758
Author(s):  
Wan Nur Fatini Syahirah W. Dagang ◽  
Shahrul Hisyam Marwan ◽  
Jamaluddin Mahmud ◽  
Nor Fazli Adull Manan ◽  
Abdul Halim Abdullah
Keyword(s):  
Pore Size ◽  
Material Properties ◽  
Biomechanical Analysis

scholarly journals Ten different hip resurfacing systems: biomechanical analysis of design and material properties

2008 ◽  
Vol 33 (4) ◽  
pp. 939-943 ◽  
Author(s):  
Christian Heisel ◽  
Jennifer A. Kleinhans ◽  
Michael Menge ◽  
Jan Philippe Kretzer
Keyword(s):  
Material Properties ◽  
Hip Resurfacing ◽  
Biomechanical Analysis

OPTIMIZATION OF FEMORAL PROSTHESIS BASED ON COMPREHENSIVE EVALUATION OF STRUCTURE AND MATERIAL PROPERTIES

2016 ◽  
Vol 16 (08) ◽  
pp. 1640013 ◽  
Author(s):  
MONAN WANG
Keyword(s):  
Carbon Fiber ◽  
Femoral Head ◽  
Material Properties ◽  
Comprehensive Evaluation ◽  
Niobium Alloy ◽  
Biomechanical Analysis ◽  
Femoral Prosthesis ◽  
Suitable Material ◽  
Multi Objective ◽  
Element Method

In this study, the optimized structure of a femoral prosthesis for a patient was determined by biomechanical analysis, and the materials that match the model of the prosthesis were determined by multi-objective comprehensive evaluation using a fuzzy matter-element method. The suitable material for the ellipsoidal femoral head of the prosthesis was determined to be a carbon-fiber-enhanced polyether-ketone (CF/PEK) composite, and that for the stem was determined to be a zirconium–niobium alloy (Zr–Nb alloy). The study successfully demonstrated the potential of the developed method for use in selecting the best structure and materials for fabricating a customized prosthesis.

scholarly journals Biomechanics of the cardiovascular system: the aorta as an illustratory example

2006 ◽  
Vol 3 (11) ◽  
pp. 719-740 ◽  
Author(s):  
Ghassan S Kassab
Keyword(s):  
Boundary Conditions ◽  
Boundary Value Problems ◽  
Material Properties ◽  
Vessel Wall ◽  
Boundary Value ◽  
Biomechanical Analysis ◽  
Surrounding Tissue ◽  
Balance Laws ◽  
Mechanical Homeostasis ◽  
Well Posed

Biomechanics relates the function of a physiological system to its structure. The objective of biomechanics is to deduce the function of a system from its geometry, material properties and boundary conditions based on the balance laws of mechanics (e.g. conservation of mass, momentum and energy). In the present review, we shall outline the general approach of biomechanics. As this is an enormously broad field, we shall consider a detailed biomechanical analysis of the aorta as an illustration. Specifically, we will consider the geometry and material properties of the aorta in conjunction with appropriate boundary conditions to formulate and solve several well-posed boundary value problems. Among other issues, we shall consider the effect of longitudinal pre-stretch and surrounding tissue on the mechanical status of the vessel wall. The solutions of the boundary value problems predict the presence of mechanical homeostasis in the vessel wall. The implications of mechanical homeostasis on growth, remodelling and postnatal development of the aorta are considered.

Ultra Low-k Materials Based on Self-Assembled Organic Polymers

2011 ◽  
Vol 1335 ◽  
Author(s):  
M. Pantouvaki ◽  
L. Zhao ◽  
C. Huffman ◽  
K. Vanstreels ◽  
I. Ciofi ◽  
...  
Keyword(s):  
Pore Size ◽  
Material Properties ◽  
Open Porosity ◽  
Dielectric Breakdown ◽  
Organic Polymers ◽  
Plasma Damage ◽  
Small Pore Size ◽  
Small Pore ◽  
Lower Porosity ◽  
Low K

ABSTRACTThe material properties of two ultra low-k organic polymers are characterized for copper interconnect integration. The k-values are 2.2-2.3 for both. Compared to OSG materials of similar k-values, these polymers have lower porosity and smaller pore size, achieved using selfassembled chemistry. Both materials demonstrate excellent resistance to plasma damage: no water uptake was detected after exposure to selected etching plasmas. This characteristic, combined with the small pore size and low porosity, results in the successful integration of the organic low-ks in 80 nm spacing with no significant increase in the integrated k-values.It is found that higher open porosity in polymer A is accompanied by higher leakage current, which is not however linked to lower dielectric breakdown lifetimes.

scholarly journals Dynamic Biomechanical Analysis of Vocal Folds Using Pipette Aspiration Technique

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 2923
Author(s):  
Florian Scheible ◽  
Raphael Lamprecht ◽  
Marion Semmler ◽  
Alexander Sutor
Keyword(s):  
Material Properties ◽  
Vocal Fold ◽  
Soft Tissues ◽  
Vocal Folds ◽  
Biomechanical Analysis ◽  
Tissue Movement ◽  
Aspiration Technique ◽  
The Voice ◽  
Shed Light

The voice producing process is a complex interplay between glottal pressure, vocal folds, their elasticity and tension. The material properties of vocal folds are still insufficiently studied, because the determination of material properties in soft tissues is often difficult and connected to extensive experimental setups. To shed light on this less researched area, in this work, a dynamic pipette aspiration technique is utilized to measure the elasticity in a frequency range of 100–1000 Hz. The complex elasticity could be assessed with the phase shift between exciting pressure and tissue movement. The dynamic pipette aspiration setup has been miniaturized with regard to a future invivo application. The techniques were applied on 3 different porcine larynges 4 h and 1 d postmortem, in order to investigate the deterioration of the tissue over time and analyze correlation in elasticity values between vocal fold pairs. It was found that vocal fold pairs do have different absolute elasticity values but similar trends. This leads to the assumption that those trends are more important for phonation than having same absolute values.

scholarly journals Effects of Pentagonal Pore Sizes in the Zinc Hydroxyapatite Parietal-Temporal Implant

2021 ◽  
Vol 11 (11) ◽  
pp. 76-85
Author(s):  
Wan Nur Fatini Syahirah W. Dagang ◽  
◽  
Nik Harisha Qistina Nik Hamdi ◽  
Shahrul Hisyam Marwan ◽  
Jamaluddin Mahmud ◽  
...  
Keyword(s):  
Pore Size ◽  
Mechanical Performance ◽  
Biomechanical Properties ◽  
Biomechanical Analysis ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Pore Sizes ◽  
Alloplastic Materials ◽  
Cranial Implant ◽  
Von Mises

To reconstruct the fractured skull, affected patients are advised to undergo cranioplasty, which is a surgical procedure to repair the cranial defect by implanting materials such as autologous bone grafts or synthetic alloplastic materials. The use of synthetic alloplastic materials such as hydroxyapatite (HA) has been widely accepted due to their biocompatibility and suitability for larger cranial defects. The zinc hydroxyapatite (ZnHA) material is favourable as HA mimics 60% of the actual human bone, whereas zinc helps to improve its biomechanical properties. The purpose of this study is to construct the ZnHA cranial implant with different pore sizes of 600, 900, and 1200 µm in pentagonal shapes and to study its mechanical performance. At the end of the research, it was found that the implant with a pore size of 900 µm is the most appropriate implant to be utilized without affecting its mechanical performance. Aspects such as the deformation and von Mises stress are discussed to assist on the development of the ZnHA cranial implant. Keywords — Biomechanical analysis, cranial implant, finite element analysis, pore size, zinc hydroxyapatite

scholarly journals A smartphone microscopic method for rapid screening of cloth facemask fabrics during pandemics

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9647
Author(s):  
Bhanu B. Neupane ◽  
Ravindra K. Chaudhary ◽  
Amita Sharma
Keyword(s):  
Pore Size ◽  
Surface Properties ◽  
Material Properties ◽  
Low Cost ◽  
Rapid Screening ◽  
Microscopic Method ◽  
Resource Limited ◽  
Fabric Materials ◽  
Local Levels ◽  
Selection Of

Background In pandemics, because of increased demand and subsequent shortage of commercial facemasks, people need to use cloth facemasks, although such masks are reported to provide reduced protection. These masks can be prepared in local levels from different fabric materials. In developing countries, cloth masks are preferable because of low cost and added advantages of reusability. The filtering performance of a cloth facemask depends on the facial fit and on the material properties of fabrics such as porosity, yarn spacing or packing, and pore size. In resource limited settings, an affordable and easy to implement method that can assess the surface properties of cloth facemask fabrics would be important. Methods In this work, we developed a smartphone microscopic method for rapid screening of fabric quality. We measured the field of view of the microscope and as a proof of concept, we implemented the method to examine surfaces of sixteen locally available cloth mask fabrics. Results Out of the 16 masks examined, we found very diverse yarn packing and pore morphology (pore size and shape) in the fabrics. The pore size ranged from ~80 to 720 μm; much larger than respiratory droplet and bio-aerosol. This observation partly explains why such cloth facemasks provide reduced protection to the user during pandemics. The performance of a cloth facemask partly depends on the material properties of fabric such as yarn packing, pore size, porosity. Therefore, the surface properties of fabrics obtained from the smartphone method can be used to get preliminary idea on the facemask quality. We believe that the method can be an affordable and rapid method for selection of better fabrics for cloth facemask during pandemics.

scholarly journals Orientation definition of anisotropy is important to finite element simulation of bone material properties

2008 ◽  
Author(s):  
Haisheng Yang ◽  
Tongtong Guo ◽  
Xin Ma
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Material Property ◽  
Material Properties ◽  
Great Influence ◽  
Biomechanical Analysis ◽  
Von Mises Stress ◽  
Bone Material ◽  
Bone Material Properties ◽  
Element Simulation

The assignment of bone material properties to finite element model is a fundamental step in finite element analysis and has great influence on analysis results. Most work done in this area has adopted isotropic assignment strategy as its simplicity. However, bone material is widely recognized as being anisotropic rather than isotropic. Therefore, this work is aimed to simulate the inhomogeneity and anisotropy of femur by assigning each element of the mesh model the material properties with a numerical integration method and properly defining the principal material orientation, and then compare the biomechanical analysis results of isotropic model with that of anisotropic model under six different loading conditions. Based on the analysis results of the equivalent Von Mises stress and the nodal displacement, four different regions of interest are chosen to achieve this comparison. The results show that significant differences between the two material property assignments exist in the regions where anisotropic material property is sensitive to orientation definition. Thus, orientation definition is important to finite element simulation of bone material properties.

Transfer Technique for Electron Microscopy of Membrance Filter Samples

1974 ◽  
Vol 32 ◽  
pp. 554-555
Author(s):  
Lawrence W. Ortiz ◽  
Bonnie L. Isom
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Pore Size ◽  
Membrane Filters ◽  
Size Dependent

A procedure is described for the quantitative transfer of fibers and particulates collected on membrane filters to electron microscope (EM) grids. Various Millipore MF filters (Millipore AA, HA, GS, and VM; 0.8, 0.45, 0.22 and 0.05 μm mean pore size) have been used with success. Observed particle losses have not been size dependent and have not exceeded 10%. With fibers (glass or asbestos) as the collected media this observed loss is approximately 3%.

Grain boundary segregation in metals

1992 ◽  
Vol 50 (2) ◽  
pp. 1204-1205
Author(s):  
C.L. Briant
Keyword(s):  
Fracture Surface ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Material Properties ◽  
Electron Spectroscopy ◽  
High Vacuum ◽  
Boundary Segregation ◽  
Grain Boundary Segregation ◽  
Local Concentration ◽  
The One

Grain boundary segregation is the process by which solute elements in a material diffuse to the grain boundaries, become trapped there, and increase their local concentration at the boundary over that in the bulk. As a result of this process this local concentration of the segregant at the grain boundary can be many orders of magnitude greater than the bulk concentration of the segregant. The importance of this problem lies in the fact that grain boundary segregation can affect many material properties such as fracture, corrosion, and grain growth.One of the best ways to study grain boundary segregation is with Auger electron spectroscopy. This spectroscopy is an extremely surface sensitive technique. When it is used to study grain boundary segregation the sample must first be fractured intergranularly in the high vacuum spectrometer. This fracture surface is then the one that is analyzed. The development of scanning Auger spectrometers have allowed researchers to first image the fracture surface that is created and then to perform analyses on individual grain boundaries.

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