scholarly journals Material properties of brachiopod shell ultrastructure by nanoindentation

2006 ◽  
Vol 4 (12) ◽  
pp. 33-39 ◽  
Author(s):  
Alberto Pérez-Huerta ◽  
Maggie Cusack ◽  
Wenzhong Zhu ◽  
Jennifer England ◽  
John Hughes
Keyword(s):  
Life Cycle ◽  
Material Properties ◽  
Materials Science ◽  
Adult Life ◽  
Young Modulus ◽  
Chemical Components ◽  
Wide Range ◽  
Mode Of Life ◽  
Modes Of Life

Mineral-producing organisms exert exquisite control on all aspects of biomineral production. Among shell-bearing organisms, a wide range of mineral fabrics are developed reflecting diverse modes of life that require different material properties. Our knowledge of how biomineral structures relate to material properties is still limited because it requires the determination of these properties on a detailed scale. Nanoindentation, mostly applied in engineering and materials science, is used here to assess, at the microstructural level, material properties of two calcite brachiopods living in the same environment but with different modes of life and shell ultrastructure. Values of hardness ( H ) and the Young modulus of elasticity ( E ) are determined by nanoindentation. In brachiopod shells, calcite semi-nacre provides a harder and stiffer structure ( H ∼3–6 GPa; E =60–110/120 GPa) than calcite fibres ( H =0–3 GPa; E =20–60/80 GPa). Thus, brachiopods with calcite semi-nacre can cement to a substrate and remain immobile during their adult life cycle. This correlation between mode of life and material properties, as a consequence of ultrastructure, begins to explain why organisms produce a wide range of structures using the same chemical components, such as calcium carbonate.

scholarly journals Adaptation and Evolution of Biological Materials

2019 ◽  
Vol 59 (6) ◽  
pp. 1629-1635
Author(s):  
Robert A Campbell ◽  
Mason N Dean
Keyword(s):  
Material Properties ◽  
Phylogenetic Relationships ◽  
Biological Material ◽  
Materials Science ◽  
Biological Materials ◽  
Materials Characterization ◽  
Selective Pressures ◽  
Wide Range ◽  
Materials Research ◽  
Biological Innovations

Abstract Research into biological materials often centers on the impressive material properties produced in Nature. In the process, however, this research often neglects the ecologies of the materials, the organismal contexts relating to how a biological material is actually used. In biology, materials are vital to organismal interactions with their environment and their physiology, and also provide records of their phylogenetic relationships and the selective pressures that drive biological novelties. With the papers in this symposium, we provide a view on cutting-edge work in biological materials science. The collected research delivers new perspectives on fundamental materials concepts, offering surprising insights into biological innovations and challenging the boundaries of materials’ characterization techniques. The topics, systems, and disciplines covered offer a glimpse into the wide range of contemporary biological materials work. They also demonstrate the need for progressive “whole organism thinking” when characterizing biological materials, and the importance of framing biological materials research in relevant, biological contexts.

scholarly journals Features of the design of structures in the conditions of Mars

2020 ◽  
Vol 26 (5) ◽  
pp. 73-89
Author(s):  
А.S. Bilyk ◽  
◽  
I.V. Hrebenieva ◽  
Keyword(s):  
Life Cycle ◽  
Negative Impact ◽  
Effective Means ◽  
Physical Parameters ◽  
Building Structures ◽  
Project Proposal ◽  
Human Needs ◽  
Research Mission ◽  
Wide Range

The article discusses the basic physical parameters and climatic features of Mars as a possible site for the construction of the first stationary research mission. They are the main factors of influence in the development of building structures for this planet. The analysis includes existing project proposals for buildings on Mars and effective means of protecting them against the negative impact of the environment, taking into account the experience of construction in complicated conditions on Earth. The detailed analysis of data allowed us to determine the parameters for the choice of location for building a colony. The parameters include soil composition, climatic indicators, terrain, level of cosmic radiation, methane fluctuations places, the equator zone, promising places for research, and successful landing places of the previous missions. Based on this, we justified the choice of the building complex location, which is the decisive factor for construction. An important aspect is also the determination of the planet colonization stages and the building requirements based on the needs of the colony. A project proposal has been developed for the second stage of planetary colonization. A colony is a quasi-closed system with its own “life cycle”, consuming only its own resources and available resources of the planet. The viability parameters of the project determine the full colony “life cycle”. We propose the hierarchical system of functions of the research mission complex. It includes five main functions: research, transport, residential, production, and recycling. The principle of hierarchy is used for the development of functional parameters of premises and the determination of links between them. In general, three blocks can be distinguished: residential, scientific, technical, and warehouse, which is organically interconnected. The system of functions is maximally optimized for human needs in Martian conditions and is designed to integrate artificial intelligence into the colony. However, the problems considered in the article are only a part of a wide range of technical, transport, financial, and other tasks that make up the range of issues of Mars development.

scholarly journals Assessment of crystallographic influence on material properties of calcite brachiopods

2008 ◽  
Vol 72 (2) ◽  
pp. 563-568 ◽  
Author(s):  
A. Pérez-Huerta ◽  
M. Cusack ◽  
W. Zhu
Keyword(s):  
Material Properties ◽  
Materials Science ◽  
High Spatial Resolution ◽  
Electron Backscatter Diffraction ◽  
Longitudinal Section ◽  
Nano Indentation ◽  
Wide Range ◽  
Unique Material ◽  
Backscatter Diffraction ◽  
Insufficient Knowledge

AbstractCalcium carbonate biominerals are frequently analysed in materials science due to their abundance, diversity and unique material properties. Aragonite nacre is intensively studied, but less information is available about the material properties of biogenic calcite, despite its occurrence in a wide range of structures in different organisms. In particular, there is insufficient knowledge about how preferential crystallographic orientations influence these material properties. Here, we study the influence of crystallography on material properties in calcite semi-nacre and fibres of brachiopod shells using nanoindentation and electron backscatter diffraction (EBSD). The nano-indentation results show that calcite semi-nacre is a harder and stiffer (H ≈ 3—5 GPa; E = 50–85 GPa) biomineral structure than calcite fibres (H = 0.4—3 GPa; E = 30—60 GPa). The integration of EBSD to these studies has revealed a relationship between the crystallography and material properties at high spatial resolution for calcite semi-nacre. The presence of crystals with the c-axis perpendicular to the plane-of-view in longitudinal section increases hardness and stiffness. The present study determines how nano-indentation and EBSD can be combined to provide a detailed understanding of biomineral structures and their analysis for application in materials science.

XBroad: program for extracting basic microstructure information from X-ray diffraction patterns in few clicks

2012 ◽  
Vol 45 (3) ◽  
pp. 594-597 ◽  
Author(s):  
Zeljko Skoko ◽  
Jasminka Popovic ◽  
Kresimir Dekanic ◽  
Vladimir Kolbas ◽  
Stanko Popovic
Keyword(s):  
Particle Size ◽  
Material Properties ◽  
Materials Science ◽  
Strain Analysis ◽  
Line Broadening ◽  
X Ray Diffraction ◽  
X Ray ◽  
Particle Size And Shape ◽  
Diffraction Patterns

XBroadis a public domain program designed for easy determination of basic microstructural information from powder X-ray diffraction data. Nowadays, preparation of nanomaterials with controlled particle size and shape has been found to be essential for tailoring the desired material properties, so a quick and effective line broadening analysis is an imperative. Although the methods implemented in the program are considered to be `traditional' ones, the authors believe that the program will provide a very fast platform for non-crystallographers working in the field of materials science, as well as for students learning the basics of size–strain analysis.

scholarly journals Determination of Modulus of Elasticity and Shear Modulus by the Measurement of Relative Strains

2016 ◽  
Vol 24 (39) ◽  
pp. 85-92
Author(s):  
Eva Labašová
Keyword(s):  
Shear Modulus ◽  
Material Properties ◽  
Modulus Of Elasticity ◽  
Theoretical Basis ◽  
Young Modulus ◽  
Secondary Level ◽  
Intellectual Skills ◽  
System Quantum ◽  
Load Conditions

Abstract This contribution is focused on determining the material properties (Young modulus and shear modulus) of the testing samples. The theoretical basis for determining material properties are the knowledge of linear elasticity and strength. The starting points are dependencies among the modulus of elasticity, shear modulus, normal stress and relative strain. The relative strains of the testing samples were obtained by measuring predefined load conditions using a strain-gauge bridge and the universal measurement system Quantum X MX 840. The integration of these tasks into the teaching process enhances practical and intellectual skills of students at secondary level technical universities.

Determination of interface width using EELS fine structure changes

1991 ◽  
Vol 49 ◽  
pp. 730-731
Author(s):  
Vinayak P. Dravid ◽  
M.R. Notis ◽  
C.E. Lyman
Keyword(s):  
Fine Structure ◽  
Materials Science ◽  
Input Parameter ◽  
Core Loss ◽  
Directionally Solidified ◽  
Interface Width ◽  
Structure Changes ◽  
Important Input ◽  
Directionally Solidified Eutectics

The concept of interfacial width is often invoked in many materials science phenomena which relate to the structure and properties of internal interfaces. The numerical value of interface width is an important input parameter in diffusion equations, sintering theories as well as in many electronic devices/processes. Most often, however, this value is guessed rather than determined or even estimated. In this paper we present a method of determining the effective structural and electronic- structural width of interphase interfaces using low- and core loss fine structure effects in EELS spectra.The specimens used in the study were directionally solidified eutectics (DSEs) in the system; NiO-ZrO2(CaO), NiO-Y2O3 and MnO-ZrO2(ss). EELS experiments were carried out using a VG HB-501 FE STEM and a Hitachi HF-2000 FE TEM.

The many faces of STEM in materials science

1991 ◽  
Vol 49 ◽  
pp. 440-441
Author(s):  
John Silcox
Keyword(s):  
Materials Science ◽  
Auger Spectroscopy ◽  
Dark Field ◽  
High Tc Superconductors ◽  
High Tc ◽  
Acoustic Environment ◽  
Electromagnetic Vibration ◽  
The Many ◽  
Serial Mode

Determination of the microstructure and microchemistry of small features often provides the insight needed for the understanding of processes in real materials. In many cases, it is not adequate to use microscopy alone. Microdiffraction and microspectroscopic information such as EELS, X-ray microprobe analysis and Auger spectroscopy can all contribute vital parts of the picture. For a number of reasons, dedicated STEM offers considerable promise as a quantitative instrument. In this paper, we review progress towards effective quantitative use of STEM with illustrations drawn from studies of high Tc superconductors, compound semiconductors and metallization of H-terminated silicon.Intrinsically, STEM is a quantitative instrument. Images are acquired directly by detectors in serial mode which is particularly convenient for digital image acquisition, control and display. The VG HB501A at Cornell has been installed in a particularly stable electromagnetic, vibration and acoustic environment. Care has been paid to achieving UHV conditions (i.e., 10-10 Torr). Finally, it has been interfaced with a VAX 3200 work station by Kirkland. This permits, for example, the acquisition of bright field (or energy loss) images and dark field images simultaneously as quantitative arrays in perfect registration.

DINAMIKA POLITIK PERSETUJUAN BERSAMA TENTANG PENETAPAN DESA ADAT DI KABUPATEN ROKAN HULU TAHUN 2014

2017 ◽  
Vol 15 (1) ◽  
pp. 21
Author(s):  
Haryo Suganda ◽  
Raja Muhammad Amin
Keyword(s):  
Regulatory Region ◽  
Field Research ◽  
Analysis Techniques ◽  
Political Dynamics ◽  
Political Interests ◽  
Wide Range ◽  
Information Method ◽  
Qualitative Descriptive ◽  
The Village

This study is motivated the identification of policies issued by the regional Governmentof Rokan Hulu in the form of Regulatory region number 1 by 2015 on the determination of thevillage and Indigenous Village. Political dynamics based on various interests against themanufacture of, and decision-making in the process of formation of the corresponding localregulations determination of Indigenous Villages in the Rokan Hulu is impacted to a verysignificantamount of changes from the initial draft of the number i.e. 21 (twenty one) the villagebecame Customary 89 (eighty-nine) the Indigenous Villages who have passed. Type of thisresearch is a qualitative descriptive data analysis techniques. The research aims to describe theState of the real situation in a systematic and accurate fact analysis unit or related research, aswell as observations of the field based on the data (information). Method of data collectionwas done with interviews, documentation, and observations through fieldwork (field research).The results of the research on the process of discussion of the draft local regulations andmutual agreement about Designation of Indigenous Villages in the Rokan Hulu is, showed thatthe political dynamics that occur due to the presence of various political interests, rejectionorally by Villagers who were judged to have met the requirements of Draft Regulations to beformulated and the area for the set to be Indigenous Villages, and also there is a desire fromsome villages in the yet to Draft local regulations in order to set the Indigenous village , there isa wide range of interests of these aspects influenced the agreement to assign the entire localVillage which is in the Rokan Hulu become Indigenous village, and the village of Transmigrationinto administrative Villages where the initiator of the changes in the number of IndigenousVillages in the Rokan Hulu it is the desire of the local Government of its own.

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