Technique for accurate determination of tensor properties of materials used in medical transducers

2002 ◽  
Author(s):  
T. Sheljaskow ◽  
A.R. Ramachandran ◽  
G. Palczewska ◽  
F. Cha
Keyword(s):  
Accurate Determination ◽  
Properties Of Materials ◽  
Materials Used

Evaluation of Micro-Pillar Compression Tests for Accurate Determination of Elastic-Plastic Constitutive Relations

2012 ◽  
Vol 79 (6) ◽  
Author(s):  
Huiyang Fei ◽  
Amit Abraham ◽  
Nikhilesh Chawla ◽  
Hanqing Jiang
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Compression Test ◽  
Constitutive Relations ◽  
Accurate Determination ◽  
Compression Tests ◽  
Element Analysis ◽  
Plastic Materials ◽  
Properties Of Materials

The micro-pillar compression test is emerging as a novel way to measure the mechanical properties of materials. In this paper, we systematically conducted finite element analysis to evaluate the capability of using a micro-compression test to probe the mechanical properties of both elastic and plastic materials. We found that this test can provide an alternative way to accurately and robustly measure strain, and to some extent, stress. Therefore, this test can be used to measure some strain related quantities, such as strain to failure, or the stress-strain relations for plastic materials.

Development of Methodological Support for the Study of Materials’ Air Permeability

2019 ◽  
Vol 945 ◽  
pp. 938-943
Author(s):  
I.A. Sheromova ◽  
A.S. Zheleznyakov
Keyword(s):  
Air Permeability ◽  
Control Procedure ◽  
Fibrous Materials ◽  
Additional Advantage ◽  
Textile Materials ◽  
The Subject ◽  
Properties Of Materials ◽  
Materials Used ◽  
Different Levels

The object of research of the article is the methodological and technical support for the process of studying the characteristics of ergonomic properties of materials used in the manufacture of garments, and the subject – the method for the determination of textile materials’ air permeability. The aim of the work is to simplify the method for determination of fibrous materials’ air permeability and to expand the technological capabilities of its instrument base while increasing the flexibility of the control procedure. To achieve this goal, the tasks related to the analysis of existing methods and technical means, and the development of a new method for determining the air permeability of textile materials were solved. The principal difference in the developed method is the possibility to conduct studies on the air permeability of textile materials at different levels of pressure drop on both sides of the sample, and not only in accordance with the standardized requirements. An additional advantage of the method is the possibility to create an online electronic database on the properties of materials. In comparison with analogues, the proposed method for the determination of air permeability ensures the accuracy and reliability of the data obtained, as well as facilitates the testing process by automation.

Measurement System for Determination of Supercapacitor Equivalent Parameters

2013 ◽  
Vol 20 (4) ◽  
pp. 581-590 ◽  
Author(s):  
Ryszard Kopka ◽  
Wiesław Tarczyński
Keyword(s):  
Measurement System ◽  
Properties Of Materials ◽  
Materials Used ◽  
Measurement Capabilities

Abstract In this paper a measurement system for determination of supercapacitor equivalent parameters is proposed. Specific properties of materials used for supercapacitor construction require some advanced tools and measurement procedures to be applied during tests. The measurement system allows to measure values of equivalent parameters by both the DC and AC method whilst keeping appropriate time criteria required by this type of devices. Furthermore, in this paper the most relevant properties and measurement capabilities of the proposed system are described as well as some exemplary values of the supercapacitor equivalent parameters measured experimentally are presented.

scholarly journals Determination of mechanical properties of materials used for 3D printing

2020 ◽  
Vol 20 (2) ◽  
pp. 190-194
Author(s):  
Josef Sedlak ◽  
Josef Chladil ◽  
Martin Cerny ◽  
Ales Polzer ◽  
Matus Varhanik ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Mechanical Properties Of Materials ◽  
Properties Of Materials ◽  
Materials Used

Defect concentration and Δn change in light- and elevated temperature- induced degradation

2021 ◽  
Author(s):  
Moonyong Kim ◽  
Matthew Wright ◽  
Daniel Chen ◽  
Catherine Chan ◽  
Alison Ciesla ◽  
...  
Keyword(s):  
Surface Passivation ◽  
Defect Density ◽  
Accurate Determination ◽  
Defect Concentration ◽  
Doping Density ◽  
Lifetime Analysis ◽  
Materials Used ◽  
New Formulation ◽  
The Impact

Abstract The wide variety of silicon materials used by various groups to investigate LeTID make it difficult to directly compare the defect concentrations (Nt) using the typical normalised defect density (NDD) metric. Here, we propose a new formulation for a relative defect concentration (β) as a correction for NDD that allows flexibility to perform lifetime analysis at arbitrary injection levels (Δn), away from the required ratio between Δn and the background doping density (Ndop) for NDD of Δn/N dop = 0.1. As such, β allows for a meaningful comparison of the maximum degradation extent between different samples in different studies and also gives a more accurate representative value to estimate the defect concentration. It also allows an extraction at the cross-over point in the undesirable presence of iron, or flexibility to reduce the impact of modulation in surface passivation. Although the accurate determination of β at a given Δn requires knowledge of the capture cross-section ratio (k), the injection-independent property of the β formulation allows a self-consistent determination of k. Experimental verification is also demonstrated for boron-oxygen related defects and LeTID defects, yielding k-values of 10.6 ± 3.2 and 30.7 ± 4.0, respectively, which are within the ranges reported in the literature. With this, when extracting the defect density at different Δn ranging between 1014 /cm3 to 1015 /cm3 with Ndop = 9.1 ×1015 /cm3, the error is less than 12% using β, allowing for a greatly improved understanding of the defect concentration in a material.

scholarly journals Equation of State of Warm Condensed Matter

1997 ◽  
Vol 499 ◽  
Author(s):  
T. W. Barbee ◽  
D. A. Young ◽  
F. J. Rogers
Keyword(s):  
Equation Of State ◽  
Finite Temperature ◽  
Condensed Matter ◽  
Accurate Determination ◽  
Temperature Limit ◽  
High Temperature Limit ◽  
Condensed Matter Theory ◽  
Matter Theory ◽  
Properties Of Materials

ABSTRACTRecent advances in computational condensed matter theory have yielded accurate calculations of properties of materials. These calculations have, for the most part, focused on the low temperature (T=0) limit. An accurate determination of the equation of state (EOS) at finite temperature also requires knowledge of the behavior of the electron and ion thermal pressure as a function of T. Current approaches often interpolate between calculated T=0 results and approximations valid in the high T limit. Plasma physics-based approaches are accurate in the high temperature limit, but lose accuracy below T∼Tfermi. We seek to “connect up” these two regimes by using ab initio finite temperature methods (including linear-response[l] based phonon calculations) to derive an equation of state of condensed matter for T<Tfermi.We will present theoretical results for the principal Hugoniot of shocked materials, including carbon and aluminum, up to pressures P>100 GPa and temperatures T> 104K, and compare our results with available experimental data.

Express-Method for Determination the Fibrous Materials Resistance to Bending

2019 ◽  
Vol 945 ◽  
pp. 407-411 ◽  
Author(s):  
I.A. Sheromova ◽  
G.P. Starkova ◽  
A.S. Zheleznyakov
Keyword(s):  
Universal Method ◽  
Fibrous Materials ◽  
Electronic Database ◽  
Natural Oscillations ◽  
The Subject ◽  
Properties Of Materials ◽  
Methodological Approaches ◽  
Materials Used ◽  
Express Methods

The object of research of the article is the characteristics of mechanical properties of fibrous systems under the bending deformation, and the subject is the method of determination of the resistance to bending. The aim of the work is to develop a new universal method for evaluating the resistance of fibrous materials to bending, including, among other things, the possibility of forming an electronic database on the characteristic properties of materials. To achieve this goal, a set of problems related to the analysis of existing methodological approaches and technical means, the rationale for possible solutions to the problem posed, and the development of a new patentable method for evaluating the materials’ resistance to bending, have been solved in the research. In the course of the project, a study was developed of the required characteristics for textile and leather-fur materials used for the manufacture of garments. The method is based on the use of natural oscillations frequencies of the material as an informative parameter of their resistance to bending. The method belongs to the class of express methods and provides an opportunity to create an electronic database on the properties of materials online. The approbation of the proposed solution by comparing the estimates obtained with the results of studies obtained on the basis of a standardized method (the method of the console), showed sufficient accuracy and the possibility of practical application of the developed method.

scholarly journals EFFECT OF DOSAGE OF REDISPUTABLE POWDERS AND THE TYPE OF LOW-MODULAR INCLUSIONS ON THE PROPERTIES OF FINE-AGGREGATE CONCRETE

2019 ◽  
Vol 46 (2) ◽  
pp. 167-175 ◽  
Author(s):  
A. V. Dolgova ◽  
G. V. Nesvetaev
Keyword(s):  
Fine Aggregate ◽  
Fine Grained ◽  
Deformation Properties ◽  
Low Modulus ◽  
Strength And Deformation ◽  
Properties Of Materials ◽  
Materials Used ◽  
Entrained Air ◽  
Polymer Powders

Objectives Reliability and durability of structures using materials with various properties (plaster coatings, cement glue, new concrete during repair and restoration of structures, etc.) largely depends on the adhesion of the layers and the deformation properties of the coatings. To obtain the required properties of materials used for coatings, modifiers based on polymers and low-modulus inclusions are introduced into the composition of new concretes, for example, entrained air. The aim of the work is to identify some patterns of change in the properties of concrete with the joint introduction of these modifiers.Method Experimental determination of the tensile strength in bending, compression, E-modulus, adhesion to the concrete base by standard methods.Result The influence of separate and joint introduction of dispersible polymer powders and various low-modulus inclusions into the composition of fine-grained concrete has been established.Conclusion The joint introduction to the composition of fine-grained concrete of various low-modulus inclusions and redispersible polymer powders provides a reduction in the stress level during forced deformations due to the different effects additives on the strength and deformation properties and contributes to increased adhesion to the concrete. 

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