The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Steve Weiner - One of the best experts on this subject based on the ideXlab platform.
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microstructure Microhardness relations in parallel fibered and lamellar bone
Bone, 1996Co-Authors: H D Wagner, Steve WeinerAbstract:Abstract Understanding the mechanical function of bone material in relation to its structure is a fascinating but very complicated problem to resolve. Part of the complexity arises from the hierarchical structural organization of bone. Microhardness measurements, initially on relatively simply structured parallel-fibered bone, show a marked anisotropy in three orthogonal directions. This may, in part, be due to the highly anisotropic structure of the basic building block of bone, the mineralized collagen fibril. Microhardness measurements made face-on to the layers of crystals and collagen triple helical molecules, show much lower values than those made edge-on to these layers. Microhardness measurements of the much more complex “rotated-plywood” structure of lamellar bone, reveal the well-known general tendency toward anisotropy in relation to the long axis of the bone. A detailed examination of Microhardness-microstructure relations of lamellar bone, however, shows that only in certain orientations can Microhardness values be related directly to a specific attribute of the lamellar structure. Clearly, the gradual tilting and rotating of the mineralized collagen fibrils that form this structure produce a material that tends toward having isotropic Microhardness properties, even though its basic building block is highly anisotropic. This may be an important structural attribute that allows lamellar bone to withstand a variety of mechanical challenges.
Luiz Andre Freire Pimenta - One of the best experts on this subject based on the ideXlab platform.
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Microhardness evaluation of in situ vital bleaching on human dental enamel using a novel study design
Dental Materials, 2005Co-Authors: Jose Augusto Rodrigues, Giselle Maria Marchi, Glaucia Maria Bovi Ambrosano, Harald O Heymann, Luiz Andre Freire PimentaAbstract:Summary Objectives The aim of this ‘in situ’ study was to evaluate the Microhardness of dental enamel following treatment with an in-office and an at-home vital bleaching agent through a novel approach using samples temporarily bonded ‘in vivo’. Methods Human dental enamel slabs ( n =88) were subjected to sequential polishing and initial Knoop Microhardness tests were performed. The slabs were fixed to the facial surfaces of the maxillary first molars of 44 human volunteers. They were divided into four groups ( n =11) according to the treatment group: G1- in-office-CP37+ at-home-CP10; G2- in-office-CP37+ at-home-PLA; G3- in-office-PLA and at-home-CP10; G4- in-office and at-home-PLA. After 3 weeks of treatment, final Microhardness measurements were performed. Results and Significance ANOVA and Tukey's HSD hoc analysis ( α =0.05) revealed no differences among initial or final Microhardness values ( p >0.05); however, significant differences occurred between initial and final values for each group ( p
Weng Yuqing - One of the best experts on this subject based on the ideXlab platform.
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analysis study of adiabatic shear band in ultra high strength low alloy steel plate
Ordnance Material Science and Engineering, 2006Co-Authors: Weng YuqingAbstract:Microstructure and Microhardness of adiabatic shear band(ASB) and those near ASB in medium carbon Cr-Ni-Mo-V ultra-high strength low alloy steel plate have been investigated.The results show that Microhardness of ASB can reach 700～830HV0.2,which is much higher than that of matrix.The microstructure of ASB is amorphous and porous.A narrow transitional band surrounds ASB and its microstructure is fine re-transformed martensite.Microstructure of a soft band(about 20 μm width) outside ASB is high temperature tempered martensite,whose Microhardness is lower than that of matrix.
C C Berndt - One of the best experts on this subject based on the ideXlab platform.
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evaluation of Microhardness and elastic modulus of thermally sprayed nanostructured zirconia coatings
Surface & Coatings Technology, 2001Co-Authors: R S Lima, Ahmet Kucuk, C C BerndtAbstract:Abstract Results concerning Microhardness and roughness ( R a ) of plasma sprayed coatings fabricated from nanostructured partially stabilized zirconia (PSZ) feedstock are presented. Nanostructured zirconia particles were plasma sprayed (Ar/H 2 ) at three power levels, with two argon flow rates at two spray distances. The results indicate that the Microhardness, elastic modulus and roughness of the nanostructured zirconia coatings exhibit the following trends: the smoother the roughness, the higher the Microhardness and elastic modulus. It was found that roughness is an indicator of the coating state that reflects the intrinsic microstructure of the coatings. It was ascertained that a surface profilometer could be used to determine the level of Microhardness and elastic modulus as a non-destructive and in situ test by simple comparison with standard samples.
H D Wagner - One of the best experts on this subject based on the ideXlab platform.
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microstructure Microhardness relations in parallel fibered and lamellar bone
Bone, 1996Co-Authors: H D Wagner, Steve WeinerAbstract:Abstract Understanding the mechanical function of bone material in relation to its structure is a fascinating but very complicated problem to resolve. Part of the complexity arises from the hierarchical structural organization of bone. Microhardness measurements, initially on relatively simply structured parallel-fibered bone, show a marked anisotropy in three orthogonal directions. This may, in part, be due to the highly anisotropic structure of the basic building block of bone, the mineralized collagen fibril. Microhardness measurements made face-on to the layers of crystals and collagen triple helical molecules, show much lower values than those made edge-on to these layers. Microhardness measurements of the much more complex “rotated-plywood” structure of lamellar bone, reveal the well-known general tendency toward anisotropy in relation to the long axis of the bone. A detailed examination of Microhardness-microstructure relations of lamellar bone, however, shows that only in certain orientations can Microhardness values be related directly to a specific attribute of the lamellar structure. Clearly, the gradual tilting and rotating of the mineralized collagen fibrils that form this structure produce a material that tends toward having isotropic Microhardness properties, even though its basic building block is highly anisotropic. This may be an important structural attribute that allows lamellar bone to withstand a variety of mechanical challenges.
