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Sample records for bone material properties

  1. Bone strength and material properties of the glenoid

    DEFF Research Database (Denmark)

    Frich, Lars Henrik; Jensen, N.C.; Odgaard, A.; Pedersen, C.M.; Sjøbjerg, J.O.; Dalstra, M.

    1997-01-01

    models were all based on assumptions that the material properties of the glenoid were similar to those of the tibial plateau. The osteopenetrometer was used to assess the topographic strength distribution at the glenoid. Strength at the proximal subchondral level of the glenoid averaged 66.9 MPa. Higher...... of the cortical bone to the total glenoid strength was assessed by compression tests of pristine and cancellous-free glenoid specimens. Strength decreased by an average of 31% after the cancellous bone was removed. The material properties of the glenoid cancellous bone were determined by axial......The quality of the glenoid bone is important to a successful total shoulder replacement. Finite element models have been used to model the response of the glenoid bone to an implanted prosthesis. Because very little is known about the bone strength and the material properties at the glenoid, these...

  2. [Effects of antiresorptive therapy on the structural and material properties of bone strength].

    Science.gov (United States)

    Kishimoto, Hideaki

    2016-01-01

    Bone strength depends on its structural and material properties. Structural properties are determined by the size and shape of bone and also the microarchitecture. Material properties are determined by mineral crystallinity, collagen structure and microdamage in bone. The strength of bone is adapted to the needs of physical activities by biologic mechanisms, bone modeling and remodeling. The deterioration of bone strength in postmenopausal women is characterized by a trabecular bone deficit with poor trabecular connectivity and followed by a cortical bone deficit with trabeculation of endocortical bone and intracortical porosity due to accelerated bone remodeling. In high turnover osteoporosis antiresorptive therapy is effective in preventing the structural deficit and in increasing the stiffness and the toughness(bone strength)by increasing the mean degree of mineralization of bone tissue through the prolongation of secondary mineralization. But the long-term use of strong antiresorber, i.e. bisphosphonate or denosumab, would result in highly mineralized bone and disturbed repair of microcracks by inhibition of bone remodeling. Intermittent use or discontinuation of strong antiresorber after about 3-5 years of administration could be recommended to avoid the deterioration of bone strength. PMID:26728537

  3. The Effects of Surface Properties of Nanostructured Bone Repair Materials on Their Performances

    Directory of Open Access Journals (Sweden)

    Feng Zhao

    2015-01-01

    Full Text Available Nanotechnology has been expected to be an extraordinarily promising method for bone repair. Meanwhile, the promise of nanobiomaterials for therapeutic applications has been widely reported, and a lot of studies have been made in terms of repairing bone using nanomaterials accompanied by rapid development of nanotechnology. Compared with conventional biomaterials, nanostructured implants have been shown to possess positive effects on cellular functions because of their unique surface properties, such as nanotopography, increased wettability, larger surface area, and microenvironment similar to extracellular matrix. Moreover, many positive cellular responses have been found to take place at the interface between nanostructured implants and host bone. In this paper, we will give a review about the effects of surface properties of nanostructured bone repair materials on their performances in terms of several aspects and a detailed interpretation or introduction on the specific cellular recognitions at the interface between nanostructured implants and host bone.

  4. New insights to the role of aryl hydrocarbon receptor in bone phenotype and in dioxin-induced modulation of bone microarchitecture and material properties

    International Nuclear Information System (INIS)

    Bone is a target for high affinity aryl hydrocarbon receptor (AHR) ligands, such as dioxins. Although bone morphology, mineral density and strength are sensitive endpoints of dioxin toxicity, less is known about effects on bone microarchitecture and material properties. This study characterizes TCDD-induced modulations of bone tissue, and the role of AHR in dioxin-induced bone toxicity and for normal bone phenotype. Six AHR-knockout (Ahr−/−) and wild-type (Ahr+/+) mice of both genders were exposed to TCDD weekly for 10 weeks, at a total dose of 200 μg/kg bw. Bones were examined with micro-computed tomography, nanoindentation and biomechanical testing. Serum levels of bone remodeling markers were analyzed, and the expression of genes related to osteogenic differentiation was profiled using PCR array. In Ahr+/+ mice, TCDD-exposure resulted in harder bone matrix, thinner and more porous cortical bone, and a more compact trabecular bone compartment. Bone remodeling markers and altered expression of a number of osteogenesis related genes indicated imbalanced bone remodeling. Untreated Ahr−/− mice displayed a slightly modified bone phenotype as compared with untreated Ahr+/+ mice, while TCDD exposure caused only a few changes in bones of Ahr−/− mice. Part of the effects of both TCDD-exposure and AHR-deficiency were gender dependent. In conclusion, exposure of adult mice to TCDD resulted in harder bone matrix, thinner cortical bone, mechanically weaker bones and most notably, increased trabecular bone volume fraction in Ahr+/+ mice. AHR is involved in bone development of a normal bone phenotype, and is crucial for manifestation of TCDD-induced bone alterations. - Highlights: • TCDD disrupts bone remodeling resulting in altered cortical and trabecular bone. • In trabecular bone an anabolic effect is observed. • Cortical bone is thinner, more porous, harder, stiffer and mechanically weaker. • AHR ablation results in increased trabecular bone and softer

  5. Material properties assignment to finite element models of bone structures: a new method.

    Science.gov (United States)

    Zannoni, C; Mantovani, R; Viceconti, M

    1998-12-01

    Finite element analysis (FEA) is widely adopted to investigate the mechanical behaviour of bone structures. Computed tomography (CT) data are frequently used to generate FE models of bone. If properly calibrated, CT images are capable of providing accurate information about the bone morphology and tissue density. The aim of this work was to develop a special program able to read a CT data set as well as the FEA mesh generated from it, and to assign to each element of the mesh the material properties derived from the bone tissue density at the element location. The program was tested on phantom data sets and was adopted to evaluate the effects of the discrete description of the bone material properties. A three-dimensional FE model was generated automatically from a 16 bit CT data set of a distal femur acquired in vivo. The strain energy density (SED) was evaluated for each model element for increasing model complexity (number of different material cards assigned to the model). The computed SED were strongly dependent on the material mapping strategy. PMID:10223642

  6. Micromechanical properties of biocompatible materials for bone tissue engineering produced by direct 3D printing

    Czech Academy of Sciences Publication Activity Database

    Koudelka_ml., P.; Doktor, T.; Kytýř, Daniel; Fenclová, Nela; Šepitka, J.; Lukeš, J.

    Vol. 662. Durnten: Trans Tech Publications, 2015 - (Kovalčíková, A.; Lofaj, F.), s. 138-141 ISBN 978-3-03835-555-7. ISSN 1013-9826. [Conference on Local Mechanical Properties (LMP 2014) /11./. Stará Lesná (SK), 12.11.2014-14.11.2014] Institutional support: RVO:68378297 Keywords : bone scaffold * nanoindenation * mechanical properties * additive manufacturing Subject RIV: JJ - Other Materials http://www.scientific.net/KEM.662.138

  7. Properties of the "Orgamax" osteoplastic material made of a demineralized allograft bone

    Science.gov (United States)

    Podorognaya, V. T.; Kirilova, I. A.; Sharkeev, Yu. P.; Uvarkin, P. V.; Zhelezny, P. A.; Zheleznaya, A. P.; Akimova, S. E.; Novoselov, V. P.; Tupikova, L. N.

    2016-08-01

    We investigated properties of the "Orgamax" osteoplastic material, which was produced from a demineralized bone, in the treatment of extensive caries, in particular chronic pulpitis of the permanent teeth with unformed roots in children. The "Orgamax" osteoplastic material consists of demineralized bone chips, a collagen additive, and antibiotics. The surface morphology of the "Orgamax" osteoplastic material is macroporous, with the maximum pore size of 250 µm, whereas the surface morphology of the major component of "Orgamax", demineralized bone chips, is microporous, with a pore size of 10-20 µm. Material "Orgamax" is used in the treatment of complicated caries, particularly chronic pulpitis of permanent teeth with unformed roots in children. "Orgamax" filling a formed cavity exhibits antimicrobial properties, eliminates inflammation in the dental pulp, and, due to its osteoconductive and osteoinductive properties, undergoes gradual resorption, stimulates regeneration, and provides replacement of the defect with newly formed tissue. The dental pulp viability is completely restored, which ensures the complete formation of tooth roots with root apex closure in the long-term period.

  8. An Injectable Hydrogel as Bone Graft Material with Added Antimicrobial Properties.

    Science.gov (United States)

    Tommasi, Giacomo; Perni, Stefano; Prokopovich, Polina

    2016-06-01

    Currently, the technique which provides the best chances for a successful bone graft, is the use of bone tissue from the same patient receiving it (autograft); the main limitations are the limited availability and the risks involved in removing living bone tissue, for example, explant site pain and morbidity. Allografts and xenografts may overcome these limitations; however, they increase the risk of rejection. For all these reasons the development of an artificial bone graft material is particularly important and hydrogels are a promising alternative for bone regeneration. Gels were prepared using 1,4-butanediol diacrylate as crosslinker and alpha tricalciumphosphate; ZnCl2 and SrCl2 were added to the aqueous phase. MTT results demonstrated that the addition of strontium had a beneficial effect on the osteoblast cells density on hydrogels, and zinc instead did not increase osteoblast proliferation. The amount of calcium produced by the osteoblast cells quantified through the Alizarin Red protocol revealed that both strontium and zinc positively influenced the formation of calcium; furthermore, their effect was synergistic. Rheology properties were used to mechanically characterize the hydrogels and especially the influence of crosslinker's concentration on them, showing the hydrogels presented had extremely good mechanical properties. Furthermore, the antimicrobial activity of strontium and zinc in the hydrogels against methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis was determined. PMID:27174392

  9. Properties of carbon nanotube-dispersed Sr-hydroxyapatite injectable material for bone defects

    OpenAIRE

    Raucci, M. G.; Alvarez-Perez, M.; Giugliano, D.; Zeppetelli, S.; Ambrosio, L.

    2016-01-01

    This study concerns the synthesis of gel materials based on carbon nanotubes dispersed strontium-modified hydroxyapatite (Sr-HA) at different compositions obtained by sol–gel technology and their influence on human-bone-marrow-derived mesenchymal stem cells. Furthermore, an evaluation of the influence of nanotubes and Strontium on physico-chemical, morphological, rheological and biological properties of hydroxyapatite gel was also performed. Morphological analysis (scanning electron microscop...

  10. New insights to the role of aryl hydrocarbon receptor in bone phenotype and in dioxin-induced modulation of bone microarchitecture and material properties

    Energy Technology Data Exchange (ETDEWEB)

    Herlin, Maria, E-mail: maria.herlin@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Finnilä, Mikko A.J., E-mail: mikko.finnila@oulu.fi [Department of Medical Technology, Institute of Biomedicine, University of Oulu, Oulu (Finland); Department of Anatomy and Cell Biology, Institute of Biomedicine, University of Oulu, Oulu (Finland); Zioupos, Peter, E-mail: p.zioupos@cranfield.ac.uk [Biomechanics Laboratories, Department of Engineering and Applied Science, Cranfield University, Shrivenham SN6 8LA (United Kingdom); Aula, Antti, E-mail: antti.aula@gmail.com [Department of Medical Physics, Imaging Centre, Tampere University Hospital, Tampere (Finland); Department of Biomedical Engineering, Tampere University of Technology, Tampere (Finland); Risteli, Juha, E-mail: juha.risteli@ppshp.fi [Department of Clinical Chemistry, Oulu University Hospital, Oulu (Finland); Miettinen, Hanna M., E-mail: hanna.miettinen@crl.com [Department of Environmental Health, National Institute for Health and Welfare, Kuopio (Finland); Jämsä, Timo, E-mail: timo.jamsa@oulu.fi [Department of Medical Technology, Institute of Biomedicine, University of Oulu, Oulu (Finland); Department of Diagnostic Radiology, Oulu University Hospital, Oulu (Finland); Tuukkanen, Juha, E-mail: juha.tuukkanen@oulu.fi [Department of Anatomy and Cell Biology, Institute of Biomedicine, University of Oulu, Oulu (Finland); Korkalainen, Merja, E-mail: merja.korkalainen@thl.fi [Department of Environmental Health, National Institute for Health and Welfare, Kuopio (Finland); Håkansson, Helen, E-mail: Helen.Hakansson@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Viluksela, Matti, E-mail: matti.viluksela@thl.fi [Department of Environmental Health, National Institute for Health and Welfare, Kuopio (Finland); Department of Environmental Science, University of Eastern Finland, Kuopio (Finland)

    2013-11-15

    Bone is a target for high affinity aryl hydrocarbon receptor (AHR) ligands, such as dioxins. Although bone morphology, mineral density and strength are sensitive endpoints of dioxin toxicity, less is known about effects on bone microarchitecture and material properties. This study characterizes TCDD-induced modulations of bone tissue, and the role of AHR in dioxin-induced bone toxicity and for normal bone phenotype. Six AHR-knockout (Ahr{sup −/−}) and wild-type (Ahr{sup +/+}) mice of both genders were exposed to TCDD weekly for 10 weeks, at a total dose of 200 μg/kg bw. Bones were examined with micro-computed tomography, nanoindentation and biomechanical testing. Serum levels of bone remodeling markers were analyzed, and the expression of genes related to osteogenic differentiation was profiled using PCR array. In Ahr{sup +/+} mice, TCDD-exposure resulted in harder bone matrix, thinner and more porous cortical bone, and a more compact trabecular bone compartment. Bone remodeling markers and altered expression of a number of osteogenesis related genes indicated imbalanced bone remodeling. Untreated Ahr{sup −/−} mice displayed a slightly modified bone phenotype as compared with untreated Ahr{sup +/+} mice, while TCDD exposure caused only a few changes in bones of Ahr{sup −/−} mice. Part of the effects of both TCDD-exposure and AHR-deficiency were gender dependent. In conclusion, exposure of adult mice to TCDD resulted in harder bone matrix, thinner cortical bone, mechanically weaker bones and most notably, increased trabecular bone volume fraction in Ahr{sup +/+} mice. AHR is involved in bone development of a normal bone phenotype, and is crucial for manifestation of TCDD-induced bone alterations. - Highlights: • TCDD disrupts bone remodeling resulting in altered cortical and trabecular bone. • In trabecular bone an anabolic effect is observed. • Cortical bone is thinner, more porous, harder, stiffer and mechanically weaker. • AHR ablation

  11. The relation of microdamage to fracture and material property degradation in human cortical bone tissue

    Science.gov (United States)

    Akkus, Ozan

    This dissertation investigates the relation of microdamage to fracture and material property degradation of human cortical bone tissue. Fracture resistance and fatigue crack growth of microcracks were examined experimentally and material property degradation was examined through theoretical modeling. To investigate the contribution of microdamage to static fracture resistance, fracture toughness tests were conducted in the transverse and longitudinal directions to the osteonal orientation of normal bone tissue. Damage accumulation was monitored by acoustic emission during testing and was spatially observed by histological observation following testing. The results suggested that the propagation of the main crack involved weakening of the tissue by diffuse damage at the fracture plane and by formation of linear microcracks away from the fracture plane for the transverse specimens. For the longitudinal specimens, growth of the main crack occurred in the form of separations at lamellar interfaces. Acoustic emission results supported the histological observations. To investigate the contribution of ultrastructure to static fracture resistance, fracture toughness tests were conducted after altering the collagen phase of the bone tissue by gamma radiation. A significant decrease in the fracture toughness, Work-to-Fracture and the amount damage was observed due to irradiation in both crack growth directions. For cortical bone irradiated at 27.5kGy, fracture toughness is reduced due to the inhibition of damage formation at and near the crack tip. Microcrack fatigue crack growth and arrest were investigated through observations of surface cracks during cyclic loading. At the applied cyclic stresses, the microcracks propagated and arrested in less than 10,000 cycles. In addition, the microcracks were observed not to grow beyond a length of 150mum and a DeltaK of 0.5MNm-3/2, supporting a microstructural barrier concept. Finally, the contribution of linear microcracks to

  12. Obesity-related changes in bone structural and material properties in hyperphagic OLETF rats and protection by voluntary wheel running

    Science.gov (United States)

    We conducted a study to examine how the development of obesity and the associated insulin resistance affect bone structural and material properties, and bone formation and resorption markers in the Otsuka Long-Evans Tokushima Fatty (OLETF) rat model. This was a 36-week study of sedentary, hyperphag...

  13. Properties of carbon nanotube-dispersed Sr-hydroxyapatite injectable material for bone defects

    Science.gov (United States)

    Raucci, M. G.; Alvarez-Perez, M.; Giugliano, D.; Zeppetelli, S.; Ambrosio, L.

    2016-01-01

    This study concerns the synthesis of gel materials based on carbon nanotubes dispersed strontium-modified hydroxyapatite (Sr-HA) at different compositions obtained by sol–gel technology and their influence on human-bone-marrow-derived mesenchymal stem cells. Furthermore, an evaluation of the influence of nanotubes and Strontium on physico-chemical, morphological, rheological and biological properties of hydroxyapatite gel was also performed. Morphological analysis (scanning electron microscopy) shows a homogeneous distribution of modified nanotubes in the ceramic matrix improving the bioactive properties of materials. The biological investigations proved that Sr-HA/carbon nanotube gel containing 0–20 mol (%) of Sr showed no toxic effect and promote the expression of early and late markers of osteogenic differentiation in cell culture performed in basal medium without osteogenic factors. Finally, the SrHA/carbon nanotube gels could have a good potential application as filler in bone repair and regeneration and may be used in the osteoporotic disease treatment. PMID:26816652

  14. Tensile material properties of human rib cortical bone under quasi-static and dynamic failure loading and influence of the bone microstucture on failure characteristics

    CERN Document Server

    Subit, Damien; Valazquez-Ameijide, Juan; Arregui-Dalmases, Carlos; Crandall, Jeff

    2011-01-01

    Finite element models of the thorax are under development to assist vehicle safety researchers with the design of countermeasures such as advanced restrain systems. Computational models have become more refined with increasing geometrical complexity as element size decreases. These finite element models can now capture small geometrical features with an attempt to predict fracture. However, the bone material properties currently available, and in particular the rate sensitivity, have been mainly determined from compression tests or tests on long bones. There is a need for a new set of material properties for the human rib cortical bone. With this objective, a new clamping technique was developed to test small bone coupons under tensile loading. Ten coupons were harvested from the cortical shell of the sixth and seventh left ribs from three cadavers. The coupons were tested to fracture under quasi-static (target strain rate of 0.07 %/s) and dynamic loading (target strain rate of 170 %/s). Prior to testing, eac...

  15. Effects of deleting cannabinoid receptor-2 on mechanical and material properties of cortical and trabecular bone

    Directory of Open Access Journals (Sweden)

    Aysha B. Khalid

    2015-12-01

    Full Text Available Cnr2 is one of two cannabinoid receptors known to regulate bone metabolism. Here, we compared the whole bone properties of femora and tibiae from three-month-old Cnr2−/- mice with wild-type controls using a C57BL/6 background. Bending stiffness was measured by three-point bending. The elastic modulus, density and mineral content were measured using ultrasound, Archimedes’ principle and ashing. Micro-CT was used to measure the second moment of area, inner and outer perimeters of the cortical shaft and trabecular parameters. Deleting Cnr2 increased the bending stiffness by increasing the second moment of area. Bone from affected male mice had a greater modulus than controls, although no difference was observed in females. The fractional volume of trabecular bone was greater in Cnr2−/- females than controls, while no difference was seen in males. These data indicate that inactivating Cnr2 increases the amount of cortical bone in both males and females at 3 months of age, but the effect on trabecular bone is different in the two sexes. These findings extend previous studies looking only at trabecular bone and provide further support for the possible use of Cnr2 antagonists for improving bone properties that may be of value in the treatment of bone disorders.

  16. The Role of Water Compartments in the Material Properties of Cortical Bone.

    Science.gov (United States)

    Granke, Mathilde; Does, Mark D; Nyman, Jeffry S

    2015-09-01

    Comprising ~20% of the volume, water is a key determinant of the mechanical behavior of cortical bone. It essentially exists in two general compartments: within pores and bound to the matrix. The amount of pore water-residing in the vascular-lacunar-canalicular space-primarily reflects intracortical porosity (i.e., open spaces within the matrix largely due to Haversian canals and resorption sites) and as such is inversely proportional to most mechanical properties of bone. Movement of water according to pressure gradients generated during dynamic loading likely confers hydraulic stiffening to the bone as well. Nonetheless, bound water is a primary contributor to the mechanical behavior of bone in that it is responsible for giving collagen the ability to confer ductility or plasticity to bone (i.e., allows deformation to continue once permanent damage begins to form in the matrix) and decreases with age along with fracture resistance. Thus, dehydration by air-drying or by solvents with less hydrogen bonding capacity causes bone to become brittle, but interestingly, it also increases stiffness and strength across the hierarchical levels of organization. Despite the importance of matrix hydration to fracture resistance, little is known about why bound water decreases with age in hydrated human bone. Using (1)H nuclear magnetic resonance (NMR), both bound and pore water concentrations in bone can be measured ex vivo because the proton relaxation times differ between the two water compartments, giving rise to two distinct signals. There are also emerging techniques to measure bound and pore water in vivo with magnetic resonance imaging (MRI). The NMR/MRI-derived bound water concentration is positively correlated with both the strength and toughness of hydrated bone and may become a useful clinical marker of fracture risk. PMID:25783011

  17. Microscale Material Properties of Bone and the Mineralized Tissues of the Intervertebral Disc-Vertebral Body Interface

    Science.gov (United States)

    Paietta, Rachel C.

    The objective of this dissertation is to understand the influences of material structure on the properties, function and failure of biological connective tissues. Biological interfaces are becoming an increasingly studied system within mechanics and tissue engineering as a model for attaching dissimilar materials. The elastic modulus of bone (≈ 20 GPa) and cartilage (≈ 0.1-1 MPa) differ over orders of magnitude, which should intuitively create high stress concentrations and failure at the interface. Yet, these natural interface systems rarely fail in vivo, and the mechanism by which loads are transferred between tissues has not yet been established. Tissue quality is one major contributor to the mechanical behavior of bone and cartilage, and is defined by properties such as collagen orientation, mineral volume fraction, porosity and tissue geometry. These properties have yet to be established at the bone-cartilage interface in the spine, and the lack of quantitative data on material microstructure and behavior limits treatments and tissue engineering construct design. In this dissertation, second harmonic generation imaging, quantitative backscattered scanning electron imaging and nanoindentation are combined to characterize micrometer scale tissue quality and modulus in both bone and calcified cartilage. These techniques are utilized to: 1) determine the hierarchical micrometer to millimeter scale properties of lamellar bone, 2) quantify changes throughout development and aging at the human intervertebral disc-vertebral body junction, and 3) explore compressive fractures at this interface. This work is the first to provide quantitative data on the mineral volume fraction, collagen orientation and modulus from the same, undecalcified sections of tissue to corroborate tissue structure and mineralization and describe quantitative parameters of the interface. The principal findings from this work indicate that the underlying matrix, or collagen, organization in

  18. Measurement of material properties of cancellous bone using small specimens and optical identification method

    Czech Academy of Sciences Publication Activity Database

    Jiroušek, Ondřej; Jírová, Jitka; Vavřík, Daniel

    Calgary : ACTA Press, 2003 - (Hamza, M.), s. 262-264 ISBN 0-88986-359-8. [IASTED International Conference on Biomechanics BioMECH 2003. Rhodos (GR), 30.06.2003-02.07.2003] R&D Projects: GA ČR GA106/01/0535 Institutional research plan: CEZ:AV0Z2071913; CEZ:MSM 212600025 Keywords : optical measurement * cancellous bone * viscoelastic properties Subject RIV: FI - Traumatology, Orthopedics

  19. Advanced Glycation Endproducts and Bone Material Properties in Type 1 Diabetic Mice

    Science.gov (United States)

    Rubin, Mishaela R.; Paschalis, Eleftherios P.; Poundarik, Atharva; Sroga, Gyna E.; McMahon, Donald J.; Gamsjaeger, Sonja; Klaushofer, Klaus; Vashishth, Deepak

    2016-01-01

    Fractures, particularly at the lower extremities and hip, are a complication of diabetes. In both type 1 (T1D) and type 2 diabetes (T2D), fracture risk is disproportionately worse than that predicted from the measurement of bone mineral density. Although an explanation for this discrepancy is the presence of organic matrix abnormalities, it has not been fully elucidated how advanced glycation endproducts (AGEs) relate to bone deterioration at both the macroscopic and microscopic levels. We hypothesized that there would be a relationship between skeletal AGE levels (determined by Raman microspectroscopy at specific anatomical locations) and bone macroscopic and microscopic properties, as demonstrated by the biomechanical measures of crack growth and microindentation respectively. We found that in OVE26 mice, a transgenic model of severe early onset T1D, AGEs were increased by Raman (carboxymethyl-lysine [CML] wildtype (WT): 0.0143 ±0.0005 vs T1D: 0.0175 ±0.0002, p = 0.003) at the periosteal surface. These differences were associated with less tough bone in T1D by fracture mechanics (propagation toughness WT: 4.73 ± 0.32 vs T1D: 3.39 ± 0.24 NM/m1/2, p = 0.010) and by reference point indentation (indentation distance increase WT: 6.85 ± 0.44 vs T1D: 9.04 ± 0.77 μm; p = 0.043). Within T1D, higher AGEs by Raman correlated inversely with macroscopic bone toughness. These data add to the existing body of knowledge regarding AGEs and the relationship between skeletal AGEs with biomechanical indices. PMID:27140650

  20. Material properties and in vitro biocompatibility of a newly developed bone cement

    OpenAIRE

    Elke Mitzner; Paco Albertus Hubert Maria Pelt; Christian Mueller; Angela Strohwig; Wolf-Dieter Mueller

    2009-01-01

    In this study mechanical properties and biocompatibility (In Vitro) of a new bone cement were investigated. A new platform technology named COOL is a variable composite of dissolved, chemically modified PMMA and different bioceramics. COOL cures at body temperature via a classical cementation reaction. Compressive strengths ranging from 3.6 ± 0.8 to 62.8 ± 1.3 MPa and bending strengths ranging from 9.9 ± 2.4 to 26.4 ± 3.0 MPa were achieved with different COOL formulations. Porosity varied bet...

  1. Tissue-specific calibration of extracellular matrix material properties by transforming growth factor-β and Runx2 in bone is required for hearing

    OpenAIRE

    Chang, Jolie L; Brauer, Delia S.; Johnson, Jacob; Chen, Carol G.; Akil, Omar; Balooch, Guive; Humphrey, Mary Beth; Chin, Emily N.; Porter, Alexandra E.; Butcher, Kristin; Ritchie, Robert O.; Schneider, Richard A; Lalwani, Anil; Derynck, Rik; Marshall, Grayson W.

    2010-01-01

    By investigating the role of bone quality in hearing, this study provides evidence that signaling pathways and lineage-specific transcription factors cooperate to define the tissue-specific and functionally essential material properties of the extracellular matrix.

  2. Material properties and in vitro biocompatibility of a newly developed bone cement

    Directory of Open Access Journals (Sweden)

    Elke Mitzner

    2009-01-01

    Full Text Available In this study mechanical properties and biocompatibility (In Vitro of a new bone cement were investigated. A new platform technology named COOL is a variable composite of dissolved, chemically modified PMMA and different bioceramics. COOL cures at body temperature via a classical cementation reaction. Compressive strengths ranging from 3.6 ± 0.8 to 62.8 ± 1.3 MPa and bending strengths ranging from 9.9 ± 2.4 to 26.4 ± 3.0 MPa were achieved with different COOL formulations. Porosity varied between 31 and 43%. Varying the components of each formulation mechanical properties and porosity could be adjusted. In Vitro biocompatibility studies with primary human osteoblasts (pHOB in direct contact with different COOL formulations, did not reveal any signs of toxicity. In contrast to Refobacin® R, cells incubated with COOL showed similar density, viability and ALP activity compared to control, if specimen were added immediately to the cell monolayer after preparation. In conclusion, COOL has promising mechanical properties in combination with high biocompatibility In Vitro and combines different advantages of both CPCs and PMMA cements by avoiding some of the respective shortcomings.

  3. Fabrication and materials properties of high-density polyethylene (HDPE)/biphasic calcium phosphate (BCP) hybrid bone plates

    International Nuclear Information System (INIS)

    Biphasic calcium phosphate-reinforced high-density polyethylene (BCP/HDPE) hybrid composite is a new orthopedic biomaterial, which was made to simulate a natural bone composition. Calcium phosphate systems and HDPE hybrid composites have been used in biomedical applications without any inflammatory response. Differences in natural bone of both materials have motivated the use of coupling agents to improve their interfacial interfacial interactions. The composites were prepared using medical grade BCP powder and granular polyethylene. This material was produced by replacing the mineral component and collagen soft tissue of the bone with BCP and HDPE, respectively. As expected, increased volume fraction of either reinforcement type over 0 ∼ 50 vol.% resulted in a increased Vickers hardness and Young's modulus. Thus, BCP particle-reinforced HDPE composites possessed improved material and mechanical properties. BCP particles-reinforced composites were anisotropic due to an alignment of the particles in the matrix during a processing. On the other hand, bending and tensile strength was dramatically changed in the matrix. To change the material and mechanical properties of HDPE/BCP composites, the process of a blending was used, and its effect on the microstructure and mechanical proprieties of HDPE/BCP composites were investigated by means of FT-IR/ATR spectroscopy, XRD, FE-SEM, Vickers Hardness Testing Machine, Universal Testing Machine, Mercury Porosimeter and Ultrasonic Flaw Detector at room temperature. For the evaluation of the cell viability and proliferation onto the external surface of HDPE/BCP hybrid plates with a HaCaT cell line, which is a multipotent cell line able to differentiate towards different phenotypes under the action of biological factors, has been evaluated with in vitro studies and quantified by colormetric assays. These findings indicate that the HDPE/BCP hybrid plates are biocompatible and non-toxic

  4. Trabecular bone as a hierarchical material

    Science.gov (United States)

    Jasiuk, Iwona

    2004-03-01

    Trabecular bone is studied as a hierarchical material. The analysis includes the experimental characterization of bone's structure, the measurement of its mechanical properties, and the mechanics modeling at several different length scales: nanoscale (under 1 micron, crystal/fiber level), sub-microscale (1-10 microns, single lamella level), microscale (10-500 microns, single trabecula level), and mesoscale (1 mm - 10 cm, trabecular structure, random network of struts or plates). Experiments include the characterization of bone's ultrastructure using SEM (scanning electron microscopy) and TEM (transmission electron microscopy) at nano and sub-microscale levels. In addition, we use the x-ray microtomography, a nondestructive technique, which can provide the three-dimensional details of bone at mesostructural level. Measurements of mechanical properties are done using the MTS machine and nanoindentation apparatus. We use the MTS testing machine to determine constitutive relations of bone at mesoscale and the nanoindentation technique to determine the properties at lower scales. The experimental observations of bone's hierarchical structure are used in the theoretical analysis of bone's mechanical properties. The calculated results are compared with the experimentally measured ones. The material properties are determined at each scale both analytically (using micromechanics theories) and numerically (using a finite element method, a spring network, and beam network approaches). The computational challenges include a complex irregular, random structure at each level, spatial heterogeneity of bone's structure, applicability of separation of scales law, size of the representative volume element, and in general the dependence of properties on specimen size and boundary conditions.

  5. Comparative evaluation of the biological properties of bone bioimplants Tutoplast® and bioactive ceramic material "Syntekost" when implanted in the middle ear in the experiment

    Directory of Open Access Journals (Sweden)

    Kravchenko S.V.

    2014-09-01

    Full Text Available Background. Trepanation cavity formed during sanitizing operation subsequently leads to a recurrence of inflammation in the middle ear cavity. A special importance in mastoidoplastics is to eliminate the postoperative cavity. One of the current problems is to create an alternative plastic material that could be used for healing of the bone defect with the newly formed bone tissue without causing further injury to the patient. Objective. The purpose of this study was to investigate and compare the features of reparative processes of bone implant Tutoplast® and bioactive ceramic material "Sintekost" as well as to assess the reaction of the inner ear to the materials which were replanted into the tympanic bullae of guinea pigs while creating an experimental model of antromastoidotomy. Methods. Experimental studies were carried out on 72 male guinea pigs of 300-400 g. Depending on the used plastic material animals were divided into 3 groups. Studies were performed on the left ear of the animal, the right ear was used as a control. Animals were withdrawn from the experiment on the 14th, 30th, 90th, 120th, 330th day. To evaluate the results of the study common histological methods were used. Results. After implanting of bioactive ceramic material "Sintekost" into tympanic bullae of guinea pigs signs of resorption of the material were mild and these processes were not always accompanied by the formation of bone tissue. The newly formed bone trabeculae were not observed until 90 day. After implanting cancellous bone crumbs "Tutoplast" into tympanic bullae of guinea pigs the initiation of osteogenesis was observed on the one hand and the resorption of bone fragments on the other. This resulted in formation of newly formed bone tissue whose volume gradually grew, filling the cavity of the tympanic bullae in that area. Implant "Tutoplast" possessed osteoplastic properties, which contributed to the growth of bone, acting as a matrix on which bone islands

  6. The Use of Micro and Nano Particulate Fillers to Modify the Mechanical and Material Properties of Acrylic Bone Cement

    Science.gov (United States)

    Slane, Joshua A.

    Acrylic bone cement (polymethyl methacrylate) is widely used in total joint replacements to provide long-term fixation of implants. In essence, bone cement acts as a grout by filling in the voids left between the implant and the patient's bone, forming a mechanical interlock. While bone cement is considered the `gold standard' for implant fixation, issues such as mechanical failure of the cement mantle (aseptic loosening) and the development of prosthetic joint infection (PJI) still plague joint replacement procedures and often necessitate revision arthroplasty. In an effort to address these failures, various modifications are commonly made to bone cement such as mechanical reinforcement with particles/fibers and the addition of antibiotics to mitigate PJI. Despite these attempts, issues such as poor particle interfacial adhesion, inadequate drug release, and the development of multidrug resistant bacteria limit the effectiveness of bone cement modifications. Therefore, the overall goal of this work was to use micro and nanoparticles to enhance the properties of acrylic bone cement, with particular emphasis placed on improving the mechanical properties, cumulative antibiotic release, and antimicrobial properties. An acrylic bone cement (Palacos R) was modified with three types of particles in various loading ratios: mesoporous silica nanoparticles (for mechanical reinforcement), xylitol microparticles (for increased antibiotic release), and silver nanoparticles (as an antimicrobial agent). These particles were used as sole modifications, not in tandem with one another. The resulting cement composites were characterized using a variety of mechanical (macro to nano, fatigue, fracture, and dynamic), imaging, chemical, thermal, biological, and antimicrobial testing techniques. The primary outcomes of this dissertation demonstrate that: (1) mesoporous silica, as used in this work, is a poor reinforcement phase for acrylic bone cement, (2) xylitol can significantly

  7. Structural properties of a bone-ceramic composite as a promising material in spinal surgery

    International Nuclear Information System (INIS)

    The paper describes the results of in vitro tests of composite bone-ceramic implants and procedures for modifying implant surfaces to enhance osteogenesis. Analysis of CBCI ESs demonstrated that they have a porous structure with the mean longitudinal pore size of 70 µm and the mean transverse pore size of 46 µm; surface pores are open, while inner pores are closed. Elemental analysis of the CBCI surface demonstrates that CBCIs are composed of aluminum and zirconium oxides and contain HA inclusions. Profilometry of the CBCI ES surface revealed the following deviations: the maximum deviation of the profile in the sample center is 15 µm and 16 µm on the periphery, while the arithmetical mean and mean square deviations of the profile are 2.65 and 3.4 µm, respectively. In addition, CBCI biodegradation products were pre-examined; a 0.9% NaCl solution was used as a comparison group. Potentially toxic and tissue accumulated elements, such as cadmium, cobalt, mercury, and lead, are present only in trace amounts and have no statistically significant differences with the comparison group, which precludes their potential toxic effects on the macroorganism. Ceramic-based CBCI may be effective and useful in medicine for restoration of the anatomic integrity and functions of the bone tissue

  8. Structural properties of a bone-ceramic composite as a promising material in spinal surgery

    Energy Technology Data Exchange (ETDEWEB)

    Kirilova, I. A., E-mail: IKirilova@mail.ru; Sadovoy, M. A.; Podorozhnaya, V. T., E-mail: VPodorognaya@niito.ru; Taranov, O. S. [Novosibirsk Research Institute of Traumatology and Orthopedics n.a. Ya.L. Tsivyan, Novosibirsk (Russian Federation); Klinkov, S. V.; Kosarev, V. F. [Christianovich Institute of Theoretical and Applied Mechanics, SB RAS, Novosibirsk (Russian Federation); Shatskaya, S. S. [Institute of Solid State Chemistry and Mechanochemistry, SB RAS, Novosibirsk (Russian Federation)

    2015-11-17

    The paper describes the results of in vitro tests of composite bone-ceramic implants and procedures for modifying implant surfaces to enhance osteogenesis. Analysis of CBCI ESs demonstrated that they have a porous structure with the mean longitudinal pore size of 70 µm and the mean transverse pore size of 46 µm; surface pores are open, while inner pores are closed. Elemental analysis of the CBCI surface demonstrates that CBCIs are composed of aluminum and zirconium oxides and contain HA inclusions. Profilometry of the CBCI ES surface revealed the following deviations: the maximum deviation of the profile in the sample center is 15 µm and 16 µm on the periphery, while the arithmetical mean and mean square deviations of the profile are 2.65 and 3.4 µm, respectively. In addition, CBCI biodegradation products were pre-examined; a 0.9% NaCl solution was used as a comparison group. Potentially toxic and tissue accumulated elements, such as cadmium, cobalt, mercury, and lead, are present only in trace amounts and have no statistically significant differences with the comparison group, which precludes their potential toxic effects on the macroorganism. Ceramic-based CBCI may be effective and useful in medicine for restoration of the anatomic integrity and functions of the bone tissue.

  9. The materials used in bone tissue engineering

    International Nuclear Information System (INIS)

    Bone tissue engineering looking for an alternative solution to the problem of skeletal injuries. The method is based on the creation of tissue engineered bone tissue equivalent with stem cells, osteogenic factors, and scaffolds - the carriers of these cells. For production of tissue engineered bone equivalent is advisable to create scaffolds similar in composition to natural extracellular matrix of the bone. This will provide optimal conditions for the cells, and produce favorable physico-mechanical properties of the final construction. This review article gives an analysis of the most promising materials for the manufacture of cell scaffolds. Biodegradable synthetic polymers are the basis for the scaffold, but it alone cannot provide adequate physical and mechanical properties of the construction, and favorable conditions for the cells. Addition of natural polymers improves the strength characteristics and bioactivity of constructions. Of the inorganic compounds, to create cell scaffolds the most widely used calcium phosphates, which give the structure adequate stiffness and significantly increase its osteoinductive capacity. Signaling molecules do not affect the physico-mechanical properties of the scaffold, but beneficial effect is on the processes of adhesion, proliferation and differentiation of cells. Biodegradation of the materials will help to fulfill the main task of bone tissue engineering - the ability to replace synthetic construct by natural tissues that will restore the original anatomical integrity of the bone

  10. The materials used in bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Tereshchenko, V. P., E-mail: tervp@ngs.ru; Kirilova, I. A.; Sadovoy, M. A.; Larionov, P. M. [Novosibirsk Research Institute of Traumatology and Orthopedics n.a. Ya.L. Tsivyan, Novosibirsk (Russian Federation)

    2015-11-17

    Bone tissue engineering looking for an alternative solution to the problem of skeletal injuries. The method is based on the creation of tissue engineered bone tissue equivalent with stem cells, osteogenic factors, and scaffolds - the carriers of these cells. For production of tissue engineered bone equivalent is advisable to create scaffolds similar in composition to natural extracellular matrix of the bone. This will provide optimal conditions for the cells, and produce favorable physico-mechanical properties of the final construction. This review article gives an analysis of the most promising materials for the manufacture of cell scaffolds. Biodegradable synthetic polymers are the basis for the scaffold, but it alone cannot provide adequate physical and mechanical properties of the construction, and favorable conditions for the cells. Addition of natural polymers improves the strength characteristics and bioactivity of constructions. Of the inorganic compounds, to create cell scaffolds the most widely used calcium phosphates, which give the structure adequate stiffness and significantly increase its osteoinductive capacity. Signaling molecules do not affect the physico-mechanical properties of the scaffold, but beneficial effect is on the processes of adhesion, proliferation and differentiation of cells. Biodegradation of the materials will help to fulfill the main task of bone tissue engineering - the ability to replace synthetic construct by natural tissues that will restore the original anatomical integrity of the bone.

  11. Mechanical properties of nacre and highly mineralized bone

    OpenAIRE

    Davies, P; Casinos, A.; Currey, J D; Zioupos, P

    2001-01-01

    We compared the mechanical properties of 'ordinary' bovine bone, the highly mineralized bone of the rostrum of the whale Mesoplodon densirostris, and mother of pearl (nacre) of the pearl oyster Pinctada margaritifera. The rostrum and the nacre are similar in having very little organic material. However, the rostral bone is much weaker and more brittle than nacre, which in these properties is close to ordinary bone. The ability of nacre to outperform rostral bone is the result of its extremely...

  12. Properties of deproteinized bone for reparation of big segmental defect in long bone

    Institute of Scientific and Technical Information of China (English)

    JIAN Yue-kui; TIAN Xiao-bin; LI Bo; QIU Bing; ZHOU Zuo-jia; YANG Zheng; LI Qi-hong

    2008-01-01

    Objective: To explore suitable scaffold material for big segmental long bone defect by studying the properties of the prepared deproteinized bone. Methods: Cancellated bone were made as 30 mm ×3 mm ×3 mm bone blocks from inferior extremity of pig femur along bone trabecula. The deproteinized bone was prepared with an improved method. Their morphological features, components, cell compatibility, mechanical and immunological properties were investigated respectively. Results: Deproteinized bone maintained natural re ticular pore system. The main organic material is collagen Ⅰand inorganic composition is hydroxyapatite. It has good mechanical properties, cell adhesion rate and histocompatibility. Conlusion: This deproteinized bone can be applicable as scaffold for reparation of big segmental defect in long bone.

  13. Effects of increased collagen-matrix density on the mechanical properties and in vivo absorbability of hydroxyapatite-collagen composites as artificial bone materials

    International Nuclear Information System (INIS)

    The aim of this study was to evaluate the effects of increased collagen-matrix density on the mechanical properties and in vivo absorbability of porous hydroxyapatite (HAp)-collagen composites as artificial bone materials. Seven types of porous HAp-collagen composites were prepared from HAp nanocrystals and dense collagen fibrils. Their densities and HAp/collagen weight ratios ranged from 122 to 331 mg cm-3 and from 20/80 to 80/20, respectively. The flexural modulus and strength increased with an increase in density, reaching 2.46 ± 0.48 and 0.651 ± 0.103 MPa, respectively. The porous composites with a higher collagen-matrix density exhibited much higher mechanical properties at the same densities, suggesting that increasing the collagen-matrix density is an effective way of improving the mechanical properties. It was also suggested that other structural factors in addition to collagen-matrix density are required to achieve bone-like mechanical properties. The in vivo absorbability of the composites was investigated in bone defects of rabbit femurs, demonstrating that the absorption rate decreased with increases in the composite density. An exhaustive increase in density is probably limited by decreases in absorbability as artificial bones.

  14. Bone Quality: The Mechanical Effects of Microarchitecture and Matrix Properties

    OpenAIRE

    Day, Judd

    2005-01-01

    textabstractIn this body of work we have examined some of the current concepts pertaining to the relation between bone mass, bone quality and the mechanical properties of bone. In our first series of studies we used a model of human osteoarthritis to investigate the implications of changes in the effective tissue modulus. Having established that the material properties of the trabecular bone were altered in the earliest stages of osteoarthritis, we then investigated a possible cause, namely th...

  15. Effect of Concurrent Use of Whole-Body Vibration and Parathyroid Hormone on Bone Structure and Material Properties of Ovariectomized Mice.

    Science.gov (United States)

    Matsumoto, Takeshi; Itamochi, Shinya; Hashimoto, Yoshihiro

    2016-05-01

    This study was designed to determine the effectiveness of whole-body vibration (WBV) and intermittent parathyroid hormone (iPTH) in combination against estrogen deficiency-induced osteoporosis. Female C57BL/6J mice were bilaterally ovariectomized (OVX, n = 40) or sham-operated (sham-OVX, n = 8) at 9 weeks of age. Two weeks later, the OVX mice were randomly divided into four groups (n = 10 each): the control group (c-OVX) and groups treated with iPTH (p-OVX), WBV (w-OVX) and both (pw-OVX). The p-OVX and pw-OVX groups were given human PTH (1-34) at a dose of 30 µg/kg/day. The w-OVX and pw-OVX groups were exposed to WBV at an acceleration of 0.3 g and 45 Hz for 20 min/day. All mice were euthanized after the 18-day treatment, and the left tibiae were harvested. The proximal metaphyseal region was µCT-scanned, and its cortical bone cross-section was analyzed by Fourier transform infrared microspectroscopy and nanoindentation testing. A single application of iPTH or WBV to OVX mice had no effect on bone structure or material properties of cortical bone, which were compromised in comparison to those in sham-OVX mice. The combination of iPTH and WBV improved trabecular bone volume, thickness, and connectivity in OVX mice. Although the combined treatment failed to improve cortical bone structure, its mineral maturity and hardness were restored to the levels observed in sham-OVX mice. There was no evidence of interaction between the two treatments, and the combined effects seemed to be additive. These results suggest combining WBV with iPTH has great potential for treating postmenopausal osteoporosis. PMID:26746476

  16. Development of highly-filled, bioactive acrylic-based composite bone cements for orthopedic and craniofacial surgery: Tuning of material properties after incorporation of calcium phosphate and antimicrobial fillers

    Science.gov (United States)

    Rodriguez, Lucas Carlos

    Bone cements are used in a variety of healthcare specialties ranging from orthopedics to dentistry to craniofacial surgery to spinal disc reconstruction. These materials need characteristics which mimic their surrounding tissues. Currently available materials have struggled to maintain these necessary characteristics. Poly (methyl methacrylate) is a very high strength bio-inert polymer which has been utilized in healthcare since the 1940's. Calcium phosphate cements are well established as being bone mimicking, but cannot sustain the compressive loads in a weight bearing application. This study sought to solve the problem of currently available bone cements by filling calcium phosphates and antimicrobials into an acrylic polymer matrix. The intended outcome was a material capable of retaining high mechanical stability from the acrylic polymer phase, while becoming sufficiently bone mimicking and antimicrobial. This thesis work presented, characterizes the material properties of the developed materials and eventually isolates a material of interest for future studies.

  17. Can the material properties of regenerate bone be predicted with non-invasive methods of assessment? Exploring the correlation between dual X-ray absorptiometry and compression testing to failure in an animal model of distraction osteogenesis

    OpenAIRE

    Monsell, Fergal; Hughes, Andrew William; Turner, James; Bellemore, Michael C.; Bilston, Lynne

    2014-01-01

    Evaluation of the material properties of regenerate bone is of fundamental importance to a successful outcome following distraction osteogenesis using an external fixator. Plain radiographs are in widespread use for assessment of alignment and the distraction gap but are unable to detect bone formation in the early stages of distraction osteogenesis and do not quantify accurately the structural properties of the regenerate. Dual X-ray absorptiometry (DXA) is a widely available non-invasive im...

  18. Mechanical properties of nacre and highly mineralized bone.

    Science.gov (United States)

    Currey, J D; Zioupos, P; Davies, P; Casino, A

    2001-01-01

    We compared the mechanical properties of 'ordinary' bovine bone, the highly mineralized bone of the rostrum of the whale Mesoplodon densirostris, and mother of pearl (nacre) of the pearl oyster Pinctada margaritifera. The rostrum and the nacre are similar in having very little organic material. However, the rostral bone is much weaker and more brittle than nacre, which in these properties is close to ordinary bone. The ability of nacre to outperform rostral bone is the result of its extremely well-ordered microstructure, with organic material forming a nearly continuous jacket round all the tiny aragonite plates, a design well adapted to produce toughness. In contrast, in the rostrum the organic material, mainly collagen, is poorly organized and discontinuous, allowing the mineral to join up to form, in effect, a brittle stony material. PMID:12123292

  19. Theory-Guided Materials Design of Multi-Phase Ti-Nb Alloys with Bone-Matching Elastic Properties

    Directory of Open Access Journals (Sweden)

    Jörg Neugebauer

    2012-10-01

    Full Text Available We present a scale-bridging approach for modeling the integral elasticresponse of polycrystalline composite that is based on a multi-disciplinary combination of(i parameter-free first-principles calculations of thermodynamic phase stability andsingle-crystal elastic stiffness; and (ii homogenization schemes developed forpolycrystalline aggregates and composites. The modeling is used as a theory-guidedbottom-up materials design strategy and applied to Ti-Nb alloys as promising candidatesfor biomedical implant applications. The theoretical results (i show an excellent agreementwith experimental data and (ii reveal a decisive influence of the multi-phase character ofthe polycrystalline composites on their integral elastic properties. The study shows thatthe results based on the density functional theory calculations at the atomistic level canbe directly used for predictions at the macroscopic scale, effectively scale-jumping severalorders of magnitude without using any empirical parameters.

  20. Recent progress in injectable bone repair materials research

    Science.gov (United States)

    Chen, Zonggang; Zhang, Xiuli; Kang, Lingzhi; Xu, Fei; Wang, Zhaoling; Cui, Fu-Zhai; Guo, Zhongwu

    2015-12-01

    Minimally invasive injectable self-setting materials are useful for bone repairs and for bone tissue regeneration in situ. Due to the potential advantages of these materials, such as causing minimal tissue injury, nearly no influence on blood supply, easy operation and negligible postoperative pain, they have shown great promises and successes in clinical applications. It has been proposed that an ideal injectable bone repair material should have features similar to that of natural bones, in terms of both the microstructure and the composition, so that it not only provides adequate stimulus to facilitate cell adhesion, proliferation and differentiation but also offers a satisfactory biological environment for new bone to grow at the implantation site. This article reviews the properties and applications of injectable bone repair materials, including those that are based on natural and synthetic polymers, calcium phosphate, calcium phosphate/polymer composites and calcium sulfate, to orthopedics and bone tissue repairs, as well as the progress made in biomimetic fabrication of injectable bone repair materials.

  1. New generation poly(ε-caprolactone)/gel-derived bioactive glass composites for bone tissue engineering: Part I. Material properties.

    Science.gov (United States)

    Dziadek, Michal; Menaszek, Elzbieta; Zagrajczuk, Barbara; Pawlik, Justyna; Cholewa-Kowalska, Katarzyna

    2015-11-01

    Poly(ε-caprolactone) (PCL) based composite films containing 12 and 21vol.% bioactive glass (SBG) microparticles were prepared by solvent casting method. Two gel-derived SBGs of SiO2-CaO-P2O5 system differing in SiO2 and CaO contents were applied (mol%): S2: 80SiO2, 16CaO, 4P2O5 and A2: 40SiO2, 54CaO, 6P2O5. The surfaces of the films in contact with Petri dish and exposed to the gas phase during casting were denoted as GS and AS, respectively. Both surfaces of films were characterised in terms of their morphology, micro- and nano-topography as well as wettability. Also mechanical properties (tensile strength, Young's modulus) and PCL matrix crystallinity (degree of crystallinity, crystal size) were evaluated. Degradation behaviour was examined by incubation of materials in UHQ-water at 37°C for 56weeks. The crystallinity, melting temperature and mass loss of incubated materials and pH changes of water were monitored. Furthermore, proliferation of MG-63 osteoblastic cells by direct contact and cytotoxic effect of obtained materials were investigated. Results showed that opposite surfaces of the same polymer and composite films differ in studied surface parameters. The addition of SBG particles into PCL matrix improves nano- and micro-roughness of both surfaces, enhances the hydrophilicity of GS surfaces (~67° for 21A2-PCL compared to ~78° for pure PCL) and also makes AS surface more hydrophobic (~94° for 21S2-PCL compared to ~86° for pure PCL). The nucleation density of PCL was increased with increasing content of SBG particles, which results in the large number of fine spherulites on composite AS surfaces observed using polarized optical (POM), scanning electron (SEM), and atomic force (AFM) microscopies. Higher content of SBG particles causes a notable increase of Young's modulus (from 0.38GPa for pure PCL, 0.90GPa for 12A2-PCL to 1.31GPa for 21A2-PCL), which also depends on SBG chemical composition. After 56-week degradation test, considerably higher

  2. New generation poly(ε-caprolactone)/gel-derived bioactive glass composites for bone tissue engineering: Part I. Material properties

    Energy Technology Data Exchange (ETDEWEB)

    Dziadek, Michal, E-mail: dziadek@agh.edu.pl [AGH University of Science and Technology, Faculty of Materials Science and Ceramics, Department of Glass Technology and Amorphous Coatings, 30 Mickiewicza Ave., 30-059 Krakow (Poland); Menaszek, Elzbieta, E-mail: elzbieta.menaszek@uj.edu.pl [Jagiellonian University, Collegium Medicum, Department of Cytobiology, 9 Medyczna St., 30-688 Krakow (Poland); Zagrajczuk, Barbara, E-mail: b.zagrajczuk@gmail.com [AGH University of Science and Technology, Faculty of Materials Science and Ceramics, Department of Glass Technology and Amorphous Coatings, 30 Mickiewicza Ave., 30-059 Krakow (Poland); Pawlik, Justyna, E-mail: pawlikj@agh.edu.pl [AGH University of Science and Technology, Faculty of Materials Science and Ceramics, Department of Glass Technology and Amorphous Coatings, 30 Mickiewicza Ave., 30-059 Krakow (Poland); Cholewa-Kowalska, Katarzyna, E-mail: cholewa@agh.edu.pl [AGH University of Science and Technology, Faculty of Materials Science and Ceramics, Department of Glass Technology and Amorphous Coatings, 30 Mickiewicza Ave., 30-059 Krakow (Poland)

    2015-11-01

    Poly(ε-caprolactone) (PCL) based composite films containing 12 and 21 vol.% bioactive glass (SBG) microparticles were prepared by solvent casting method. Two gel-derived SBGs of SiO{sub 2}–CaO–P{sub 2}O{sub 5} system differing in SiO{sub 2} and CaO contents were applied (mol%): S2: 80SiO{sub 2}, 16CaO, 4P{sub 2}O{sub 5} and A2: 40SiO{sub 2}, 54CaO, 6P{sub 2}O{sub 5}. The surfaces of the films in contact with Petri dish and exposed to the gas phase during casting were denoted as GS and AS, respectively. Both surfaces of films were characterised in terms of their morphology, micro- and nano-topography as well as wettability. Also mechanical properties (tensile strength, Young's modulus) and PCL matrix crystallinity (degree of crystallinity, crystal size) were evaluated. Degradation behaviour was examined by incubation of materials in UHQ-water at 37 °C for 56 weeks. The crystallinity, melting temperature and mass loss of incubated materials and pH changes of water were monitored. Furthermore, proliferation of MG-63 osteoblastic cells by direct contact and cytotoxic effect of obtained materials were investigated. Results showed that opposite surfaces of the same polymer and composite films differ in studied surface parameters. The addition of SBG particles into PCL matrix improves nano- and micro-roughness of both surfaces, enhances the hydrophilicity of GS surfaces (~ 67° for 21A2-PCL compared to ~ 78° for pure PCL) and also makes AS surface more hydrophobic (~ 94° for 21S2-PCL compared to ~ 86° for pure PCL). The nucleation density of PCL was increased with increasing content of SBG particles, which results in the large number of fine spherulites on composite AS surfaces observed using polarized optical (POM), scanning electron (SEM), and atomic force (AFM) microscopies. Higher content of SBG particles causes a notable increase of Young's modulus (from 0.38 GPa for pure PCL, 0.90 GPa for 12A2-PCL to 1.31 GPa for 21A2-PCL), which also depends on

  3. New generation poly(ε-caprolactone)/gel-derived bioactive glass composites for bone tissue engineering: Part I. Material properties

    International Nuclear Information System (INIS)

    Poly(ε-caprolactone) (PCL) based composite films containing 12 and 21 vol.% bioactive glass (SBG) microparticles were prepared by solvent casting method. Two gel-derived SBGs of SiO2–CaO–P2O5 system differing in SiO2 and CaO contents were applied (mol%): S2: 80SiO2, 16CaO, 4P2O5 and A2: 40SiO2, 54CaO, 6P2O5. The surfaces of the films in contact with Petri dish and exposed to the gas phase during casting were denoted as GS and AS, respectively. Both surfaces of films were characterised in terms of their morphology, micro- and nano-topography as well as wettability. Also mechanical properties (tensile strength, Young's modulus) and PCL matrix crystallinity (degree of crystallinity, crystal size) were evaluated. Degradation behaviour was examined by incubation of materials in UHQ-water at 37 °C for 56 weeks. The crystallinity, melting temperature and mass loss of incubated materials and pH changes of water were monitored. Furthermore, proliferation of MG-63 osteoblastic cells by direct contact and cytotoxic effect of obtained materials were investigated. Results showed that opposite surfaces of the same polymer and composite films differ in studied surface parameters. The addition of SBG particles into PCL matrix improves nano- and micro-roughness of both surfaces, enhances the hydrophilicity of GS surfaces (~ 67° for 21A2-PCL compared to ~ 78° for pure PCL) and also makes AS surface more hydrophobic (~ 94° for 21S2-PCL compared to ~ 86° for pure PCL). The nucleation density of PCL was increased with increasing content of SBG particles, which results in the large number of fine spherulites on composite AS surfaces observed using polarized optical (POM), scanning electron (SEM), and atomic force (AFM) microscopies. Higher content of SBG particles causes a notable increase of Young's modulus (from 0.38 GPa for pure PCL, 0.90 GPa for 12A2-PCL to 1.31 GPa for 21A2-PCL), which also depends on SBG chemical composition. After 56-week degradation test

  4. Can the material properties of regenerate bone be predicted with non-invasive methods of assessment? Exploring the correlation between dual X-ray absorptiometry and compression testing to failure in an animal model of distraction osteogenesis.

    Science.gov (United States)

    Monsell, Fergal; Hughes, Andrew William; Turner, James; Bellemore, Michael C; Bilston, Lynne

    2014-04-01

    Evaluation of the material properties of regenerate bone is of fundamental importance to a successful outcome following distraction osteogenesis using an external fixator. Plain radiographs are in widespread use for assessment of alignment and the distraction gap but are unable to detect bone formation in the early stages of distraction osteogenesis and do not quantify accurately the structural properties of the regenerate. Dual X-ray absorptiometry (DXA) is a widely available non-invasive imaging modality that, unlike X-ray, can be used to measure bone mineral content (BMC) and density quantitatively. In order to be useful as a clinical investigation; however, the structural two-dimensional geometry and density distributions assessed by DXA should reflect material properties such as modulus and also predict the structural mechanical properties of the regenerate bone formed. We explored the hypothesis that there is a relationship between DXA assessment of regenerate bone and structural mechanical properties in an animal model of distraction osteogenesis. Distraction osteogenesis was carried out on the tibial diaphysis of 41 male, 12 week old, New Zealand white rabbits as part of a larger study. Distraction started after a latent period of 24 h at a rate of 0.375 mm every 12 h and continued for 10-days, achieving average lengthening of 7.1 mm. Following an 18-day period of consolidation, the regenerate bone was subject to bone density measurements using a total body dual-energy X-ray densitometer. This produced measurement of BMC, bone mineral density (BMD) and volumetric bone mineral density (vBMD). The tibiae were then disarticulated and cleaned of soft tissue before loading in compression to failure using an Instron mechanical testing machine (Instron Corporation, Massachusetts USA). Using Spearman rank correlation and linear regression, there was a significant correlation between vBMD and the Modulus of Elasticity, Yield Stress and Failure Stress of the

  5. Material for bone tissue engineering

    Czech Academy of Sciences Publication Activity Database

    Vetrík, Miroslav; Pařízek, Martin; Policianová, Olivia; Hlídková, Helena; Přádný, Martin; Hrubý, Martin; Lisá, Věra; Bačáková, Lucie

    Bratislava : Young Scientists Council of Polymer Institute of Slovak Academy of Sciences, 2016. s. 77. ISBN 978-80-970923-8-2. [Bratislava Young Polymer Scientists workshop /6./ - BYPoS 2016. 14.03.2016-18.03.2016, Ždiar] R&D Projects: GA MŠk(CZ) LM2015064 Institutional support: RVO:61389013 ; RVO:67985823 Keywords : black orlon * bone tissue * tissue engineering Subject RIV: CE - Biochemistry; EI - Biotechnology ; Bionics (FGU-C)

  6. Multifunctional materials for bone cancer treatment

    Directory of Open Access Journals (Sweden)

    Marques C

    2014-05-01

    Full Text Available Catarina Marques,1 José MF Ferreira,1 Ecaterina Andronescu,2 Denisa Ficai,2 Maria Sonmez,3 Anton Ficai21Department of Materials and Ceramics Engineering, Centre for Research in Ceramics and Composite Materials, University of Aveiro, Aveiro, Portugal; 2Faculty of Applied Chemistry and Material Science, University Politehnica of Bucharest, Bucharest, Romania; 3National Research and Development Institute for Textiles and Leather, Bucharest, RomaniaAbstract: The purpose of this review is to present the most recent findings in bone tissue engineering. Special attention is given to multifunctional materials based on collagen and collagen–hydroxyapatite composites used for skin and bone cancer treatments. The multifunctionality of these materials was obtained by adding to the base regenerative grafts proper components, such as ferrites (magnetite being the most important representative, cytostatics (cisplatin, carboplatin, vincristine, methotrexate, paclitaxel, doxorubicin, silver nanoparticles, antibiotics (anthracyclines, geldanamycin, and/or analgesics (ibuprofen, fentanyl. The suitability of complex systems for the intended applications was systematically analyzed. The developmental possibilities of multifunctional materials with regenerative and curative roles (antitumoral as well as pain management in the field of skin and bone cancer treatment are discussed. It is worth mentioning that better materials are likely to be developed by combining conventional and unconventional experimental strategies.Keywords: bone graft, cancer, collagen, magnetite, cytostatics, silver

  7. Using the gradient of human cortical bone properties to determine age-related bone changes via ultrasonic guided waves.

    Science.gov (United States)

    Baron, Cécile

    2012-06-01

    Bone fragility depends not only on bone mass but also on bone quality (structure and material). To accurately evaluate fracture risk or propose therapeutic treatment, clinicians need a criterion, which reflects the determinants of bone strength: geometry, structure and material. In human long bone, the changes due to aging, accentuated by osteoporosis are often revealed through the trabecularization of cortical bone, i.e., increased porosity of endosteal bone inducing a thinning of the cortex. Consequently, the intracortical porosity gradient corresponding to the spatial variation in porosity across the cortical thickness is representative of loss of mass, changes in geometry (thinning) and variations in structure (porosity). This article examines the gradient of material properties and its age-related evolution as a relevant parameter to assess bone geometry, structure and material. By applying a homogenization process, cortical bone can be considered as an anisotropic functionally graded material with variations in material properties. A semi-analytical method based on the sextic Stroh formalism is proposed to solve the wave equation in an anisotropic functionally graded waveguide for two geometries, a plate and a tube, without using a multilayered model to represent the structure. This method provides an analytical solution called the matricant and explicitly expressed under the Peano series expansion form. Our findings indicate that ultrasonic guided waves are sensitive to the age-related evolution of realistic gradients in human bone properties across the cortical thickness and have their place in a multimodal clinical protocol. PMID:22502890

  8. Technologies to explore gamma radiation influence on structurally depended exoemission properties of bone

    Energy Technology Data Exchange (ETDEWEB)

    Zakaria, M.; Bogucarska, T.; Noskov, V.; Dekhtyar, Y. [Riga Technical Univ. (Latvia). Inst. of Biomedical Engineering and Nanotechnologies

    2005-09-15

    This article deals with the estimation of inserted defects in bone material by gamma radiation used for radiation therapy. Exoelectron emission (EE) phenomenon underlies a new electron spectroscopy to explore alteration of the electronic structurally dependence properties of bone material. The influence of gamma radiation with different energies on the bone structure had been discussed.

  9. Physical properties of aged and non-aged human bones

    International Nuclear Information System (INIS)

    The main purpose of the present research was to select physical methods to characterise the electronic and mechanical properties of human bones from XIII-XX centuries. The compared technologies were targeted to explore the bone material at macro, micro and nano scales. For this roentgenography, magnetic nuclear resonance, X-ray computer and ultrasound tomography, micro-hardness, atomic force microscope, X-ray diffraction and exoelectron spectroscopy (ES) were employed. The results demonstrate that the most sensitive technology to characterise of the bones is ES. (authors)

  10. Biomimetic strengthening polylactide scaffold materials for bone tissue engineering

    Institute of Scientific and Technical Information of China (English)

    XU Guofu; MOU Shenzhou; ZHOU Lingping; LIAO Susan; YIN Zhimin; CUI Fuzhai

    2007-01-01

    In this paper,a new polylactide(PLA)-based scaffold composite by biomimetic synthesis was designed.The novel composite mainly consists ofnano-hydroxyapatite (n-HA),which is the main inorganic content in natural bone tissue for the PLA.The crystal degree of the n-HA in the composite is low and the crystal size is very small,which is similar to that of natural bone.The compressive strength of the composite is higher than that of the PLA scaffold.Using the osteoblast culture technique,we detected cell behaviors on the biomaterial in vitro by SEM,and the cell affinity of the composite was found to be higher than that of the PLA scaffold.The biomimetic three-dimensional porous composite can serve as a kind of excellent scaffold material for bone tissue engineering because of its microstructure and properties.

  11. OSL properties of anthropological bone and tooth

    Energy Technology Data Exchange (ETDEWEB)

    Meric, Niyazi [Department of Engineering Physics, Faculty of Engineering, Ankara University, 06100 Besevler-Ankara (Turkey)], E-mail: meric@ankara.edu.tr; Kosal, Mehmet [Department of Engineering Physics, Faculty of Engineering, Ankara University, 06100 Besevler-Ankara (Turkey)], E-mail: kosal@eng.ankara.edu.tr; Altay Atlihan, M. [Department of Engineering Physics, Faculty of Engineering, Ankara University, 06100 Besevler-Ankara (Turkey)], E-mail: atlihan@eng.ankara.edu.tr; Rabia Yuece, Ulkue [Department of Engineering Physics, Faculty of Engineering, Ankara University, 06100 Besevler-Ankara (Turkey)], E-mail: ulku.yuce@taek.gov.tr

    2008-06-15

    The aim of present work was to investigate whether anthropological bone and teeth can be used in dosimetric and dating studies. The radiation dose responses of anthropological human bone and pig teeth were obtained and studied using infrared stimulated luminescence (IRSL). The radiation dose responses of these materials were found to be compatible with commonly used feldspar and quartz compounds. The IRSL signal was shown to be linear with a radiation dose until {approx}200 Gy and stable at ambient temperature, which may allow the use of such materials for dating.

  12. OSL properties of anthropological bone and tooth

    International Nuclear Information System (INIS)

    The aim of present work was to investigate whether anthropological bone and teeth can be used in dosimetric and dating studies. The radiation dose responses of anthropological human bone and pig teeth were obtained and studied using infrared stimulated luminescence (IRSL). The radiation dose responses of these materials were found to be compatible with commonly used feldspar and quartz compounds. The IRSL signal was shown to be linear with a radiation dose until ∼200 Gy and stable at ambient temperature, which may allow the use of such materials for dating

  13. Physicomechanical properties of the extracellular matrix of a demineralized bone

    Science.gov (United States)

    Kirilova, I. A.; Sharkeev, Yu. P.; Nikolaev, S. V.; Podorozhnaya, V. T.; Uvarkin, P. V.; Ratushnyak, A. S.; Chebodaeva, V. V.

    2016-08-01

    The article describes the results of a study of physicomechanical properties of a demineralized bone matrix of human cancellous and compact bones. A demineralized cancellous bone was shown to have the best characteristics of a porous system for colonization of matrices by cells. The ultimate stress and elasticity modulus of samples of demineralized femoral heads isolated in primary hip replacement was demonstrated to vary in wide ranges. The elasticity modulus ranged from 50 to 250 MPa, and the tensile strength varied from 1.1 to 5.5 MPa. Microhardness measurements by the recovered indentation method were not possible because of the viscoelastic properties of a bone material. To study the piezoelectric properties of samples, a measuring system was developed that comprised a measuring chamber with contact electrodes, a system for controlled sample loading, an amplifier-converter unit, and signal recording and processing software. The measurement results were used to determine the dependence of the signal amplitude on the dynamic deformation characteristics. The findings are discussed in terms of the relationship between the mechanical and electrical properties and the structure of the organic bone component.

  14. Post-yield and failure properties of cortical bone.

    Science.gov (United States)

    Wolfram, Uwe; Schwiedrzik, Jakob

    2016-01-01

    Ageing and associated skeletal diseases pose a significant challenge for health care systems worldwide. Age-related fractures have a serious impact on personal, social and economic wellbeing. A significant proportion of physiological loading is carried by the cortical shell. Its role in the fracture resistance and strength of whole bones in the ageing skeleton is of utmost importance. Even though a large body of knowledge has been accumulated on this topic on the macroscale, the underlying micromechanical material behaviour and the scale transition of bone's mechanical properties are yet to be uncovered. Therefore, this review aims at providing an overview of the state-of-the-art of the post-yield and failure properties of cortical bone at the extracellular matrix and the tissue level. PMID:27579166

  15. Development of a piezoelectric bone substitute material

    CERN Document Server

    Al-Bader, Y A

    2000-01-01

    The thesis deals with the preparation and testing of ceramic compositions to be used as bone substitute. The proposed composition consisted of calcium enriched calcium phosphate, kaolin and barium titanate in different ratios. The homogeneous powder mixture was dry pressed at different pressures and fired at temperatures up to 1350 degC for different soaking times. The physical properties of the fired compacts that were tested are bulk density and porosity. These were determined as function of pressing pressure, firing temperature and soaking time for different compositions. The mechanical properties investigated were the ultimate compressive strength and Young's modulus, which were determined for different compositions and forming pressures. The electrical properties investigated were D.C. characteristics (resistivity) and A.C. characteristics (A.C. resistivity, dielectric constant, dielectric loss and loss tangent). The piezoelectric behaviour of the fired compacts was investigated and the piezoelectric coe...

  16. [Sarcopenia and bone mineral property with age].

    Science.gov (United States)

    Ogawa, Sumito

    2016-08-01

    In order to maintain functional activities in the elderly, promotion of musculoskeletal care is important toward successful aging and healthy longevity. In practice, reduction of falls and fall-related injuries together with treatment of osteoporosis is important to keep activities of daily living. Recent findings suggest the possibility that there is a relationship between skeletal muscle and bone mineral property, represented by pathophysiological linkage between sarcopenia and osteoporosis. PMID:27461501

  17. Bone loss without the loss of bone mineral material? A new perspective on anorexia nervosa.

    Science.gov (United States)

    Bolotin, H H

    2009-06-01

    Since the advent on non-invasive in vivo clinical bone densitometry, investigators have reported that regional bone mineral material loss accompanies the onset and continuance of anorexia nervosa (AN). Initial single-energy photon absorptiometric (SPA) studies were followed by a succession of dual-energy X-ray absorptiometric (DXA) investigations, and a few single-energy quantitative computer assisted tomographic (SEQCT) bone densitometry vertebral measurements. Although most all DXA studies found a relatively small diminution (approximately 3%) of bone mineral material at lumbar vertebral and proximal femoral bone-sites of AN-afflicted adolescent girls and young women, these findings have been consensually interpreted and near-universally accepted as losses of actual bone mineral material accompanying AN. It has also been claimed by some that about 50% of those beset by AN while still young adolescents were osteoporotic. Nonetheless, over the last intervening 2 decades of these studies, no specific underlying direct bone-biological causal link between AN and trabecular bone material loss has yet been uncovered. The present exposition shows that in vivo SPA, DXA, and SEQCT measurements of bone mineral material losses do not constitute evidence of actual loss of bone material, and that the attribution of osteopenia and osteoporosis to AN-afflicted younger adolescent girls is not sustainable. Rather, the full gamut of these reported bone material "losses" can be accounted for by the already well-documented AN-induced changes in the anthropometrics and compositional mixes of extra-osseous soft tissues (primarily in a very noticeable reduction of extra-skeletal fat) and intra-osseous bone marrow yellowing (marrow hypoplasia and marrow cell necrosis). These changes in soft tissue compositions and anthropometrics alone have been shown to be sufficient to cause in vivo SPA, DXA, and SEQCT to systematically mis-estimate true bone material density and erroneously register

  18. Organ and tissue level properties are more sensitive to age than osteocyte lacunar characteristics in rat cortical bone

    DEFF Research Database (Denmark)

    Wittig, Nina; Bach-Gansmo, Fiona Linnea; Birkbak, Mie Elholm;

    2016-01-01

    Modeling and remodeling induce significant changes of bone structure and mechanical properties with age. Therefore, it is important to gain knowledge of the processes taking place in bone over time. The rat is a widely used animal model, where much data has been accumulated on age-related changes...... orientation with animal age. Hence, the evolution of organ and tissue level properties with age in rat cortical bone is not accompanied by related changes in osteocyte lacunar properties. This suggests that bone microstructure and bone matrix material properties and not the geometric properties...

  19. Electrical properties of materials

    CERN Document Server

    Solymar, L; Syms, R R A

    2014-01-01

    An informal and highly accessible writing style, a simple treatment of mathematics, and clear guide to applications have made this book a classic text in electrical and electronic engineering. Students will find it both readable and comprehensive. The fundamental ideas relevant to the understanding of the electrical properties of materials are emphasized; in addition, topics are selected in order to explain the operation of devices having applications (or possible future applications) in engineering. The mathematics, kept deliberately to a minimum, is well within the grasp of a second-year student. This is achieved by choosing the simplest model that can display the essential properties of a phenomenom, and then examining the difference between the ideal and the actual behaviour. The whole text is designed as an undergraduate course. However most individual sections are self contained and can be used as background reading in graduate courses, and for interested persons who want to explore advances in microele...

  20. Effect of storage on osteoinductive properties of demineralized bone in rats

    DEFF Research Database (Denmark)

    Pinholt, E M; Solheim, E

    1994-01-01

    A requirement for the clinical use of demineralized bone is the possibility of storing the material without loss of its osteoinductive properties. Seventy-five 8-week-old male Wistar rats were randomly assigned to one of five groups of 15 rats each. Lyophilized demineralized allogeneic bone...

  1. Degradability of injectable calcium sulfate/mineralized collagen-based bone repair material and its effect on bone tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zonggang, E-mail: chenzg@sdu.edu.cn [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Kang, Lingzhi [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Meng, Qing-Yuan [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Liu, Huanye [Department of Prosthodontics, School of Stomatology, China Medical University, Shenyang 110001 (China); Wang, Zhaoliang [Jinan Military General Hospital of PLA, Jinan 250031 (China); Guo, Zhongwu, E-mail: zwguo@sdu.edu.cn [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Cui, Fu-Zhai, E-mail: cuifz@mail.tsinghua.edu.cn [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2014-12-01

    The nHAC/CSH composite is an injectable bone repair material with controllable injectability and self-setting properties prepared by introducing calcium sulfate hemihydrate (CSH) into mineralized collagen (nHAC). When mixed with water, the nHAC/CSH composites can be transformed into mineralized collagen/calcium sulfate dihydrate (nHAC/CSD) composites. The nHAC/CSD composites have good biocompatibility and osteogenic capability. Considering that the degradation behavior of bone repair material is another important factor for its clinical applications, the degradability of nHAC/CSD composites was studied. The results showed that the degradation ratio of the nHAC/CSD composites with lower nHAC content increased with the L/S ratio increase of injectable materials, but the variety of L/S ratio had no significant effect on the degradation ratio of the nHAC/CSD composites with higher nHAC content. Increasing nHAC content in the composites could slow down the degradation of nHAC/CSD composite. Setting accelerator had no significant effect on the degradability of nHAC/CSD composites. In vivo histological analysis suggests that the degradation rate of materials can match the growth rate of new mandibular bone tissues in the implanted site of rabbit. The regulable degradability of materials resulting from the special prescriptions of injectable nHAC/CSH composites will further improve the workability of nHAC/CSD composites. - Highlights: • The nHAC/CSH composite can be as an injectable bone repair material. • The L/S ratio and nHAC content have a significant effect on material degradability. • The degradability of bone materials can be regulated to match tissue repair. • The regulable degradability will further improve the workability of bone materials.

  2. Degradability of injectable calcium sulfate/mineralized collagen-based bone repair material and its effect on bone tissue regeneration

    International Nuclear Information System (INIS)

    The nHAC/CSH composite is an injectable bone repair material with controllable injectability and self-setting properties prepared by introducing calcium sulfate hemihydrate (CSH) into mineralized collagen (nHAC). When mixed with water, the nHAC/CSH composites can be transformed into mineralized collagen/calcium sulfate dihydrate (nHAC/CSD) composites. The nHAC/CSD composites have good biocompatibility and osteogenic capability. Considering that the degradation behavior of bone repair material is another important factor for its clinical applications, the degradability of nHAC/CSD composites was studied. The results showed that the degradation ratio of the nHAC/CSD composites with lower nHAC content increased with the L/S ratio increase of injectable materials, but the variety of L/S ratio had no significant effect on the degradation ratio of the nHAC/CSD composites with higher nHAC content. Increasing nHAC content in the composites could slow down the degradation of nHAC/CSD composite. Setting accelerator had no significant effect on the degradability of nHAC/CSD composites. In vivo histological analysis suggests that the degradation rate of materials can match the growth rate of new mandibular bone tissues in the implanted site of rabbit. The regulable degradability of materials resulting from the special prescriptions of injectable nHAC/CSH composites will further improve the workability of nHAC/CSD composites. - Highlights: • The nHAC/CSH composite can be as an injectable bone repair material. • The L/S ratio and nHAC content have a significant effect on material degradability. • The degradability of bone materials can be regulated to match tissue repair. • The regulable degradability will further improve the workability of bone materials

  3. Biomechanical Properties of Bone and Biomechanics of Age - Related Fractures - Review

    Directory of Open Access Journals (Sweden)

    Rezzan Günaydın

    2007-06-01

    Full Text Available From a biomechanical viewpoint, fractures are due to a structural failure of the bone. This failure occurs when the forces applied to the bone exceed its load – bearing capacity. The load – bearing capacity of a bone depends on the geometry (its size, shape and distribution of bone mass, and the material properties of a bone as well as the direction and magnitude of applied load. Bone fragility can be defined by biomechanical parameters such as strength, brittleness and work to failure. Strategies to reduce fracture risk must be based on a sound understanding of the cellular, molecular and biomechanical mechanisms that underlie the increased risk of fractures while aging. In this review biomechanics of bone and the etiology of age – related fractures from a biomechanical viewpoint have been discussed in the view of current literature. (From the World of Osteoporosis 2007;13:44-8

  4. Macroscopic properties of model disordered materials

    International Nuclear Information System (INIS)

    Disordered materials are ubiquitous in nature and in industry. Soils, sedimentary rocks, wood, bone, polymer composites, foams, catalysts, gels, concretes and ceramics have properties that depend on material structure. Present techniques for predicting properties are limited by the theoretical and computational difficulty of incorporating a realistic description of material structure. A general model for microstructure was recently proposed by Berk [Berk, Phys.Rev.A, 44 5069 (1991)]. The model is based on level cuts of a Gaussian random field with arbitrary spectral density. The freedom in specifying the parameters of the model allows the modeling of physical materials with diverse morphological characteristics. We have shown that the model qualitatively accounts for the principal features of a wider variety of disordered materials including geologic media, membranes, polymer blends, ceramics and foams. Correlation functions are derived for the model microstructure. From this characterisation we derive mechanical and conductive properties of the materials. Excellent agreement with experimentally measured properties of disordered solids is obtained. The agreement provides a strong hint that it is now possible to correlate effective physical properties of porous solids to microstructure. Simple extensions to modelling properties of non-porous multicomponent blends; metal alloys, ceramics, metal/matrix and polymer composites are also discussed

  5. Anisotropy of bovine cortical bone tissue damage properties.

    Science.gov (United States)

    Szabó, M E; Thurner, P J

    2013-01-01

    Bone is a heterogeneous, anisotropic natural composite material. Several studies have measured human cortical bone elastic properties in different anatomical directions and found that the Young's modulus was highest in the longitudinal, followed by the tangential and then by the radial direction. This study compared the Young's modulus, the accumulated microdamage and local strains related to the failure process in these three anatomical directions. Cortical bone samples (≈360 μm×360 μm) were mechanically tested in three-point bending and concomitantly imaged to assess local strains using digital image correlation technique. The bone whitening effect was used to detect microdamage formation and propagation. No statistically significant difference was found between the Young's modulus of longitudinal (9.4±2.0 GPa) and tangential (9.9±1.8 GPa) bovine bone samples, as opposed to previous findings on human bone samples. The same similarity was found for the whitening values (5000±1900 pix/mm(2) for longitudinal, 5800±2600 pix/mm(2) for tangential) and failure strains (16.8±7.0% for longitudinal, 19.1±3.2% for tangential) as well. However, significantly lower values were observed in the radial samples for Young's modulus (5.92±0.77 GPa), whitening (none or minimal) and failure strain (10.8±3.8%). For strains at whitening onset, no statistically significant difference was seen for the longitudinal (5.1±1.6%) and radial groups (4.2±2.0%), however, the tangential values were significantly greater (7.0±2.4%). The data implies that bovine cortical bone tissue in long bones is designed to withstand higher loads in the longitudinal and tangential directions than in the radial one. A possible explanation of the anisotropy in the mechanical parameters derived here might be the structure of the tissues in the three directions tested. PMID:23063771

  6. A comparative study of zirconium and titanium implants in rat: osseointegration and bone material quality.

    Science.gov (United States)

    Hoerth, Rebecca M; Katunar, María R; Gomez Sanchez, Andrea; Orellano, Juan C; Ceré, Silvia M; Wagermaier, Wolfgang; Ballarre, Josefina

    2014-02-01

    Permanent metal implants are widely used in human medical treatments and orthopedics, for example as hip joint replacements. They are commonly made of titanium alloys and beyond the optimization of this established material, it is also essential to explore alternative implant materials in view of improved osseointegration. The aim of our study was to characterize the implant performance of zirconium in comparison to titanium implants. Zirconium implants have been characterized in a previous study concerning material properties and surface characteristics in vitro, such as oxide layer thickness and surface roughness. In the present study, we compare bone material quality around zirconium and titanium implants in terms of osseointegration and therefore characterized bone material properties in a rat model using a multi-method approach. We used light and electron microscopy, micro Raman spectroscopy, micro X-ray fluorescence and X-ray scattering techniques to investigate the osseointegration in terms of compositional and structural properties of the newly formed bone. Regarding the mineralization level, the mineral composition, and the alignment and order of the mineral particles, our results show that the maturity of the newly formed bone after 8 weeks of implantation is already very high. In conclusion, the bone material quality obtained for zirconium implants is at least as good as for titanium. It seems that the zirconium implants can be a good candidate for using as permanent metal prosthesis for orthopedic treatments. PMID:24170339

  7. Mechanical Properties of Cranial Bones and Sutures in 1–2-Year-Old Infants

    OpenAIRE

    Wang, Jiawen; Zou, Donghua; LI, ZHENGDONG; Huang, Ping; Li, Dongri; Shao, Yu; Wang, Huijun; Chen, Yijiu

    2014-01-01

    Background The mechanical properties of 1–2-year-old pediatric cranial bones and sutures and their influential factors were studied to better understand how the pediatric calvarium reacts to loading. Material/Methods Cranial bone and suture specimens were extracted from seven fresh-frozen human infant cadavers (1.5±0.5 years old). Eight specimens were obtained from each subject: two frontal bones, two parietal bones, two sagittal suture samples, and two coronal suture samples. The specimens w...

  8. APPLICATION OF A BIODEGRADABLE MATERIAL FOR BONE REPLACEMENT IN TRAUMATOLOGY

    Directory of Open Access Journals (Sweden)

    T. V. Druzhinina

    2014-01-01

    Full Text Available 20 men (medium age (31.5 ± 13.5 years were studied. All patients underwent arthroscopic auditing plastic anterior cruciate ligament of the knee. Osteoregeneration dynamics were determined by biochemical testing of blood serum and X-ray computed tomography (CT of the fracture in 1–4 months after surgery. As a result, an estimation of the bone tissue reparative regeneration according to CT data in 10 patients with a defect of the patella, treated with the material is provided. The obtained results of the clinical study indicate the reparative effect of the biodegradable material for bone replacing on bone regeneration

  9. Material properties in complement activation

    DEFF Research Database (Denmark)

    Moghimi, S. Moein; Andersen, Alina Joukainen; Ahmadvand, Davoud;

    2011-01-01

    activation differently and through different sensing molecules and initiation pathways. The importance of material properties in triggering complement is considered and mechanistic aspects discussed. Mechanistic understanding of complement events could provide rational approaches for improved material design...

  10. Study on the storage stability of Xeno-bone graft material by irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hak Jyung; Kim, Jae Hun; Lee, Ju Woon; Choi, Jong Il [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Kim, Tae Woon [R and D Center, Jeonbuk Technopark, Jeongeup (Korea, Republic of)

    2010-12-15

    In this study, the microbial safety and mechanical properties of xeno-bone graft material irradiated were investigated during the storage. Xeno-bone graft of the deminerlized bone matrix in carboxy-methyl-cellulose was gamma-irradiated and was cultured in PCA and PDA agar to check microbial contamination. Total aerobic bacteria and fungi were not detected in the irradiated and non-irradiated sample stored in accelerator at 30 .deg. C for 10 months. Viscosity of CMC treated gamma irradiation was also not changed by holding period.

  11. Topography of Acoustical Properties of Long Bones: From Biomechanical Studies to Bone Health Assessment

    OpenAIRE

    Tatarinov, Alexey; Sarvazyan, Armen

    2008-01-01

    The article presents a retrospective view on the assessment of long bones condition using topographical patterns of the acoustic properties. The application of ultrasonic point-contact transducers with exponential waveguides on a short acoustic base for detailed measurements in human long bones by the surface transmission was initiated during the 1980s in Latvia. The guided wave velocity was mapped on the surface of the long bones and the topographical patterns reflected the biomechanical pec...

  12. Instrumental neutron activation analysis of rib bone samples and of bone reference materials

    International Nuclear Information System (INIS)

    The instrumental neutron activation analysis method was used for the determination of trace elements in rib bone samples taken from autopsies of accident victims. The elements Br, Ca, Cl, Cr, Fe, Mg, Mn, Na, P, Sr, Rb and Zn were determined in cortical tissues by using short and long irradiations with thermal neutron flux of the IEA-R1m nuclear reactor. The reference materials NIST SRM 1400 Bone Ash and NIST SRM 1486 Bone Meal were also analyzed in order to evaluate the precision and the accuracy of the results. It was verified that lyophilization is the most convenient process for drying bone samples since it does not cause any element losses. Comparisons were made between the results obtained for rib samples and the literature values as well as between the results obtained for different ribs from a single individual and for bones from different individuals. (author)

  13. Tensile behaviour and properties of a bone analogue composite (HA, HDPE) crosslinked by gamma radiation

    International Nuclear Information System (INIS)

    A natural composite material, hydroxyapatite (HA) and high density polyethylene (HDPE) crosslinked by ionizing radiations is been developed as a bioactive analogue material for bone replacement. Mechanical properties of the composites irradiated up to 300 kGy under tensile tests was studied. Gel content and micrographs of different composite fractures are shown. (author)

  14. Porous Materials - Structure and Properties

    DEFF Research Database (Denmark)

    Nielsen, Anders

    The paper presents some viewpoints on the description of the pore structure and the modelling of the properties of the porous building materials. Two examples are given , where it has been possible to connect the pore structure to the properties: Shrinkage of autoclaved aerated concrete and the...... properties of lime mortar....

  15. Osteocyte lacunar properties in rat cortical bone

    DEFF Research Database (Denmark)

    Bach-Gansmo, Fiona Linnea; Weaver, James C.; Jensen, Mads Hartmann;

    2015-01-01

    Recently, the roles of osteocytes in bone maintenance have gained increasing attention. Osteocytes reside in lacunae that are interconnected by canaliculi resulting in a vast cellular network within the mineralized bone matrix. As the structure of the lacuno-canalicular network is highly connecte...

  16. Effect of biomaterial properties on bone healing in a rabbit tooth extraction socket model.

    Science.gov (United States)

    Fisher, John P; Lalani, Zahid; Bossano, Carla M; Brey, Eric M; Demian, Nagi; Johnston, Carol M; Dean, David; Jansen, John A; Wong, Mark E K; Mikos, Antonios G

    2004-03-01

    In this work we sought to understand the effect of biomaterial properties upon healing bone tissue. We hypothesized that a hydrophilic polymer gel implanted into a bone tissue defect would impede the healing process owing to the biomaterial's prevention of protein adsorption and thus cell adhesion. To test this hypothesis, healing bone was investigated within a rabbit incisor extraction socket, a subcritical size bone defect that resists significant soft tissue invasion by virtue of its conformity. After removal of the incisor teeth, one tooth socket was left as an empty control, one was filled with crosslinked polymer networks formed from the hydrophobic polymer poly(propylene fumarate) (PPF), and one was filled with a hydrogel formed from the hydrophilic oligomer oligo(poly(ethylene glycol) fumarate) (OPF). At five different times (4 days as well as 1, 2, 4, and 8 weeks), jaw bone specimens containing the tooth sockets were removed. We analyzed bone healing by histomorphometrical analysis of hematoxylin and eosin stained sections as well as immunohistochemically stained sections. The proposed hypothesis, that a hydrophilic material would hinder bone healing, was supported by the histomorphometrical results. In addition, the immunohistochemical results reflect molecular signaling indicative of the early invasion of platelets, the vascularization of wound-healing tissue, the differentiation of migrating progenitor cells, and the formation and remodeling of bone tissue. Finally, the results emphasize the need to consider biomaterial properties and their differing effects upon endogenous growth factors, and thus bone healing, during the development of tissue engineering devices. PMID:14762922

  17. Optical properties of advanced materials

    CERN Document Server

    Kajikawa, Kotaro

    2013-01-01

    In the last decade, optically functionalized materials have developed rapidly, from bulk matters to structured forms. Now we have a rich variety of attractive advanced materials. They are applied to optical and electrical devices that support the information communication technology in the mid 21-th century. Accordingly, it is quite important to have a broad knowledge of the optical properties of advanced materials for students, scientists and engineers working in optics and related fields. This book is designed to teach fundamental optical properties of such advanced materials effectively. These materials have their own peculiarities which are very interesting in modern optical physics and also for applications because the concepts of optical properties are quite different from those in conventional optical materials. Hence each chapter starts to review the basic concepts of the materials briefly and proceeds to the practical use. The important topics covered in this book include:  quantum structures of sem...

  18. The Role of Collagen Organization on the Properties of Bone.

    Science.gov (United States)

    Garnero, Patrick

    2015-09-01

    Bone is a complex tissue constituted by a collagen matrix filled in with crystal of hydroxyapatite (HAP). Bone mechanical properties are influenced by the collagen matrix which is organized into hierarchical structures from the individual type I collagen heterotrimer flanked by linear telopeptides at each end to the collagen fibrils that are interconnected by enzymatic and non-enzymatic cross-links. Although most studies focused on the role of collagen cross-links in bone strength, other organizational features may also play a role. At the molecular level it has been shown that homotrimer of type I collagen found in bone tissue of some patients with osteogenesis imperfecta (OI) is characterized by decreased mechanical competence compared to the regular heterotrimer. The state of C-telopeptide isomerization-which can be estimated by the measurement in body fluids of the native and isomerized isoforms-has also been shown to be associated with bone strength, particularly the post-yield properties independent of bone size and bone mineral density. Other higher hierarchical features of collagen organization have shown to be associated with changes in bone mechanical behavior in ex vivo models and may also be relevant to explain bone fragility in diseases characterized by collagen abnormalities e.g., OI and Paget's disease. These include the orientation of collagen fibrils in a regular longitudinal direction, the D-spacing period between collagen fibrils and the collagen-HAP interfacial bonding. Preliminary data indicate that some of these organizational features can change during treatment with bisphosphonate, raloxifene, and PTH suggesting that they may contribute to their anti-fracture efficacy. It remains however to be determined which of these parameters play a specific and independent role in bone matrix properties, what is the magnitude of mechanical strength explained by collagen organization, whether they are relevant to explain osteoporosis-induced bone

  19. Autologous bone marrow stem cells--properties and advantages.

    Science.gov (United States)

    Rice, Claire M; Scolding, Neil J

    2008-02-15

    The properties of self-renewal and multi-lineage differentiation make stem cells attractive candidates for use in cellular reparative therapy, particularly in neurological diseases where there is a paucity of treatment options. However, clinical trials using foetal material in Parkinson's disease have been disappointing and highlighted problems associated with the use of embryonic stem cells, including ethical issues and practical concerns regarding teratoma formation. Understandably, this has led investigators to explore alternative sources of stem cells for transplantation. The expression of neuroectodermal markers by cells of bone marrow origin focused attention on these adult stem cells. Although early enthusiasm has been tempered by dispute regarding the validity of reports of in vitro (trans)differentiation, the demonstration of functional benefit in animal models of neurological disease is encouraging. Here we will review some of the required properties of stem cells for use in transplantation therapy with specific reference to the development of bone marrow-derived cells as a source of cells for repair in demyelination. PMID:17669432

  20. Various effects of antidepressant drugs on bone microarchitectecture, mechanical properties and bone remodeling

    International Nuclear Information System (INIS)

    The aim of this study was to evaluate the effects of various drugs which present antidepressant properties: selective serotonin-reuptake inhibitors (SSRIs, fluoxetine), serotonin and noradrenaline-reuptake inhibitors (Desipramine) and phosphodiesterase inhibitors (PDE, rolipram and tofisopam) on bone microarchitecture and biomechanical properties. Twelve female mice were studied per group starting at an age of 10 weeks. During 4 weeks, they received subcutaneously either placebo or 20 mg kg-1 day-1 of desipramine, fluoxetine or 10 mg kg-1 day-1 of rolipram or tofisopam. Serum Osteocalcin and CTx were evaluated by ELISA. Bone microarchitecture of the distal femur was characterized by X-ray microCT (Skyscan1072). Mechanical properties were assessed by three-point bending test (Instron 4501) and antidepressant efficacy by forced swimming and open field tests. Fluoxetine displayed lower TbTh (- 6.1%, p -1, 6431 ± 1182 MPa) than in placebo (101 ± 9 N mm-1, 8441 ± 1180 MPa). Bone markers indicated a significantly higher bone formation in tofisopam (+ 8.6%) and a lower in fluoxetine (- 56.1%) compared to placebo. These data suggest deleterious effects for SSRIs, both on trabecular and cortical bone and a positive effect of PDE inhibitors on trabecular bone. Furthermore tofisopam anabolic effect in terms of bone markers, suggests a potential therapeutic effect of the PDE inhibitors on bone

  1. Chemical and physical properties of bone cement for vertebroplasty

    Directory of Open Access Journals (Sweden)

    Po-Liang Lai

    2013-08-01

    Full Text Available Vertebral compression fracture is the most common complication of osteoporosis. It may result in persistent severe pain and limited mobility, and significantly impacts the quality of life. Vertebroplasty involves a percutaneous injection of bone cement into the collapsed vertebrae by fluorescent guide. The most commonly used bone cement in percutaneous vertebroplasty is based on the polymerization of methylmethacrylate monomers to polymethylmethacrylate (PMMA polymers. However, information on the properties of bone cement is mostly published in the biomaterial sciences literature, a source with which the clinical community is generally unfamiliar. This review focuses on the chemistry of bone cement polymerization and the physical properties of PMMA. The effects of altering the portions and contents of monomer liquid and polymer powders on the setting time, polymerization temperature, and compressive strength of the cement are also discussed. This information will allow spine surgeons to manipulate bone cement characteristics for specific clinical applications and improve safety.

  2. Multifunctional materials for bone cancer treatment

    OpenAIRE

    Marques C; JMF Ferreira; Andronescu E; Ficai D; Sonmez M.; Ficai A

    2014-01-01

    Catarina Marques,1 José MF Ferreira,1 Ecaterina Andronescu,2 Denisa Ficai,2 Maria Sonmez,3 Anton Ficai21Department of Materials and Ceramics Engineering, Centre for Research in Ceramics and Composite Materials, University of Aveiro, Aveiro, Portugal; 2Faculty of Applied Chemistry and Material Science, University Politehnica of Bucharest, Bucharest, Romania; 3National Research and Development Institute for Textiles and Leather, Bucharest, RomaniaAbstract: The purpose of this review ...

  3. High rate properties of porcine skull bone tissue

    Science.gov (United States)

    Herwig, Kyle Jeffry

    Several recent studies have shown the importance of understanding the nature of blast injuries. Traditionally, the lungs and other air filled organs were the focus of these injuries but it is being discovered that some level of brain trauma may result after encountering a blast. These injuries are referred to as traumatic brain injuries, or TBI. There has been many clinical studies and statistical analyses done concerning these injuries, but there is still no physical understanding of the problem. In order to develop a model of how this injury can occur, rate dependent material properties of the tissues the stress wave will travel through are needed. In this study, the compressive response of porcine skull bone through the thickness direction was experimentally determined over a wide range of rates, ranging from 0.001 sec -1 to approximately 3000 sec-1. The results reveal that for most mechanical properties there is a clear rate dependence of the material. However, only one subset of the skull section appeared to have a rate dependent initial modulus, with the rest showing no significant statistical dependence on loading rate. Other mechanical properties appeared to be affected by the loading rate, including the strain energy density.

  4. Porous Materials - Structure and Properties

    DEFF Research Database (Denmark)

    Nielsen, Anders

    1997-01-01

    The paper presents some viewpoints on the description of the pore structure and the modelling of the properties of the porous building materials. Two examples are given , where it has been possible to connect the pore structure to the properties: Shrinkage of autoclaved aerated concrete and the...

  5. Tailoring of epoxy material properties

    OpenAIRE

    Nakka, J.S.

    2010-01-01

    This research work is aimed to understand the effect of resin chemistry on the physical properties (e.g. moduli, viscoelasticity, moisture uptake, coefficient of thermal expansion) of cured aromatic epoxy-amine thermoset resins. This understanding will result into a good first approximation of the final properties. As a consequence in future it will be possible to design a resin with a well defined set of material properties. Although this research work cannot be generalized to all kinds of p...

  6. Mechanical Properties of Materials

    CERN Document Server

    Pelleg, Joshua

    2013-01-01

    The subject of mechanical behavior has been in the front line of basic studies in engineering curricula for many years.  This textbook was written for engineering students with the aim of presenting, in a relatively simple manner, the basic concepts of mechanical behavior in solid materials. A second aim of the book is to guide students in their laboratory experiments by helping them to understand their observations in parallel with the lectures of their various courses; therefore the first chapter of the book is devoted to mechanical testing. Another aim of the book is to provide practicing engineers with basic help to bridge the gap of time that has passed from their graduation up to their actual involvement in engineering work. The book also serves as the basis for more advanced studies and seminars when pursuing courses on a graduate level. The content of this textbook and the topics discussed correspond to courses that are usually taught in universities and colleges all over the world, but with a differ...

  7. Influence of cortical endplates on ultrasonic properties of trabecular bone

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yoon Mi; Lee, Kang Il [Dept. of Physics, Kangwon National University, Chuncheon (Korea, Republic of)

    2015-04-15

    The present study investigated the influence of thick cortical endplates on the ultrasonic properties of trabecular bone in a femur with a high fracture risk. Twelve trabecular bone samples were prepared from bovine femurs, and acrylic plates with thicknesses of 1.25, 1.80, and 2.75 mm were manufactured to simulate the cortical endplates using acrylic with a density and a sound speed similar to cortical bone. Although the thickness of the acrylic plates attached to the two sides of the trabecular bone increased, high correlations were observed between the speed of sound and the apparent bone density of the trabecular bone, with Pearson's correlation coefficients of 0.80-0.86. High correlations were also observed between the attenuation coefficient at 0.5 mm and the apparent bone density of the trabecular bone, with Pearson's correlation coefficients of 0.84-0.91. These results suggest that the speed of sound and attenuation coefficient at a specific frequency measured in a femur with relatively thick cortical endplates compared to the calcaneus could be used as indices for predicting the bone mineral density of the femur.

  8. Influence of cortical endplates on ultrasonic properties of trabecular bone

    International Nuclear Information System (INIS)

    The present study investigated the influence of thick cortical endplates on the ultrasonic properties of trabecular bone in a femur with a high fracture risk. Twelve trabecular bone samples were prepared from bovine femurs, and acrylic plates with thicknesses of 1.25, 1.80, and 2.75 mm were manufactured to simulate the cortical endplates using acrylic with a density and a sound speed similar to cortical bone. Although the thickness of the acrylic plates attached to the two sides of the trabecular bone increased, high correlations were observed between the speed of sound and the apparent bone density of the trabecular bone, with Pearson's correlation coefficients of 0.80-0.86. High correlations were also observed between the attenuation coefficient at 0.5 mm and the apparent bone density of the trabecular bone, with Pearson's correlation coefficients of 0.84-0.91. These results suggest that the speed of sound and attenuation coefficient at a specific frequency measured in a femur with relatively thick cortical endplates compared to the calcaneus could be used as indices for predicting the bone mineral density of the femur.

  9. Organ and tissue level properties are more sensitive to age than osteocyte lacunar characteristics in rat cortical bone

    Directory of Open Access Journals (Sweden)

    Nina Kølln Wittig

    2016-06-01

    Full Text Available Modeling and remodeling induce significant changes of bone structure and mechanical properties with age. Therefore, it is important to gain knowledge of the processes taking place in bone over time. The rat is a widely used animal model, where much data has been accumulated on age-related changes of bone on the organ and tissue level, whereas features on the nano- and micrometer scale are much less explored. We investigated the age-related development of organ and tissue level bone properties such as bone volume, bone mineral density, and load to fracture and correlated these with osteocyte lacunar properties in rat cortical bone. Femora of 14 to 42-week-old female Wistar rats were investigated using multiple complementary techniques including X-ray micro-computed tomography and biomechanical testing. The body weight, femoral length, aBMD, load to fracture, tissue volume, bone volume, and tissue density were found to increase rapidly with age at 14–30 weeks. At the age of 30–42 weeks, the growth rate appeared to decrease. However, no accompanying changes were found in osteocyte lacunar properties such as lacunar volume, ellipsoidal radii, lacunar stretch, lacunar oblateness, or lacunar orientation with animal age. Hence, the evolution of organ and tissue level properties with age in rat cortical bone is not accompanied by related changes in osteocyte lacunar properties. This suggests that bone microstructure and bone matrix material properties and not the geometric properties of the osteocyte lacunar network are main determinants of the properties of the bone on larger length scales.

  10. Prediction of the Setting Properties of Calcium Phosphate Bone Cement

    Directory of Open Access Journals (Sweden)

    Seyed Mahmud Rabiee

    2012-01-01

    Full Text Available Setting properties of bone substitutes are improved using an injectable system. The injectable bone graft substitutes can be molded to the shape of the bone cavity and set in situ when injected. Such system is useful for surgical operation. The powder part of the injectable bone cement is included of β-tricalcium phosphate, calcium carbonate, and dicalcium phosphate and the liquid part contains poly ethylene glycol solution with different concentrations. In this way, prediction of the mechanical properties, setting times, and injectability helps to optimize the calcium phosphate bone cement properties. The objective of this study is development of three different adaptive neurofuzzy inference systems (ANFISs for estimation of compression strength, setting time, and injectability using the data generated based on experimental observations. The input parameters of models are polyethylene glycol percent and liquid/powder ratio. Comparison of the predicted values and measured data indicates that the ANFIS model has an acceptable performance to the estimation of calcium phosphate bone cement properties.

  11. Prediction of the setting properties of calcium phosphate bone cement.

    Science.gov (United States)

    Rabiee, Seyed Mahmud; Baseri, Hamid

    2012-01-01

    Setting properties of bone substitutes are improved using an injectable system. The injectable bone graft substitutes can be molded to the shape of the bone cavity and set in situ when injected. Such system is useful for surgical operation. The powder part of the injectable bone cement is included of β-tricalcium phosphate, calcium carbonate, and dicalcium phosphate and the liquid part contains poly ethylene glycol solution with different concentrations. In this way, prediction of the mechanical properties, setting times, and injectability helps to optimize the calcium phosphate bone cement properties. The objective of this study is development of three different adaptive neurofuzzy inference systems (ANFISs) for estimation of compression strength, setting time, and injectability using the data generated based on experimental observations. The input parameters of models are polyethylene glycol percent and liquid/powder ratio. Comparison of the predicted values and measured data indicates that the ANFIS model has an acceptable performance to the estimation of calcium phosphate bone cement properties. PMID:22919372

  12. Bone tissue induction, using a COLLOSS-filled titanium fibre mesh-scaffolding material.

    Science.gov (United States)

    Walboomers, X Frank; Jansen, John A

    2005-08-01

    Scaffold materials for bone tissue engineering often are supplemented with bone morphogenetic proteins (BMPs). In the current study we aimed to investigate COLLOSS, a bovine extracellular matrix product containing native BMPs. Hollow cylindrical implants were made, with a length of 10 mm, a 3 mm inner diameter, and a 5 mm outer diameter, from titanium fibre mesh. The central space of the tube was filled with 20 mg COLLOSS. Subsequently, these implants, as well as non-loaded controls, were implanted subcutaneously into the back of Wistar rats, with n=6 for all study groups. After implantation periods of 2, 8, and 12 weeks, tissue-covered implants were retrieved, and sections were made, perpendicular to the long axis of the tube. Histology showed, that all implants were surrounded by a thin fibrous tissue capsule. After 2 weeks of implantation, the COLLOSS material was reduced in size inside the loaded implants, but no bone-like tissue formation was evident. After 8 weeks, in two out of six loaded specimens, new-formed bone- and bone marrow-like tissues could be observed. After 12 weeks, this had increased to five out of six COLLOSS-loaded samples. The amount of bone-like tissue did not differ between 8 and 12 weeks, and on average occupied 15% of the central space of the tube. In the non-loaded control samples, only connective tissue ingrowth was observed. In conclusion, we can say that COLLOSS material loaded in a titanium fibre mesh tube, showed bone-inducing properties. The final efficacy of these osteo-inductive properties has to be confirmed in future large animal studies. PMID:15763257

  13. Analysis of anisotropic viscoelastoplastic properties of cortical bone tissues.

    Science.gov (United States)

    Abdel-Wahab, Adel A; Alam, Khurshid; Silberschmidt, Vadim V

    2011-07-01

    Bone fractures affect the health of many people and have a significant social and economic effect. Often, bones fracture due to impacts, sudden falls or trauma. In order to numerically model the fracture of a cortical bone tissue caused by an impact it is important to know parameters characterising its viscoelastoplastic behaviour. These parameters should be measured for various orientations in a bone tissue to assess bone's anisotropy linked to its microstructure. So, the first part of this study was focused on quantification of elastic-plastic behaviour of cortical bone using specimens cut along different directions with regard to the bone axis-longitudinal (axial) and transverse. Due to pronounced non-linearity of the elastic-plastic behaviour of the tissue, cyclic loading-unloading uniaxial tension tests were performed to obtain the magnitudes of elastic moduli not only from the initial loading part of the cycle but also from its unloading part. Additional tests were performed with different deformation rates to study the bone's strain-rate sensitivity. The second part of this study covered creep and relaxation properties of cortical bone for two directions and four different anatomical positions-anterior, posterior, medial and lateral-to study the variability of bone's properties. Since viscoelastoplasticity of cortical bone affects its damping properties due to energy dissipation, the Dynamic Mechanical Analysis (DMA) technique was used in the last part of our study to obtain magnitudes of storage and loss moduli for various frequencies. Based on analysis of elastic-plastic behaviour of the bovine cortical bone tissue, it was found that magnitudes of the longitudinal Young's modulus for four cortical positions were in the range of 15-24 GPa, while the transversal modulus was lower--between 10 and 15 GPa. Axial strength for various anatomical positions was also higher than transversal strength with significant differences in magnitudes for those positions

  14. How Does The Bone Shaft Geometry Affect its Bending Properties?

    Directory of Open Access Journals (Sweden)

    Kaveh P. Saffar

    2009-01-01

    Full Text Available In this research, ten fresh specimens of sheep tibiae were provided from slaughtered animals. Whole bone specimens were loaded in three-point bending according to standard wet bone test protocols. Mechanical properties were determined and compared with the results which were obtained from two dry bone tests. The results showed that fracture bending moment and bone extrinsic stiffness had significant relations with fracture cross-section dependent parameters (i.e., cross-section area and area moment of inertia. Where, fracture energy and ultimate strength did not have such a relation with these parameters. Finite element modeling of bone shaft was made with simplified geometry (neglecting cross-section variations along bone shaft in two steps: First, by elliptical cross-section and second, by circular cross-section, assuming linear elastic and isotropic properties for the specimens. Elastic (Young’s modulus and fracture load, evaluated from curves obtained from tests, were applied to the finite element model and close results of maximum stress in both test specimen and first (elliptical cross-section model showed up. There was an average difference of about 2% between ultimate strength of wet bone specimens and maximum (tensile stress occurred in the elliptical models. However, this value for circular models was about 16%.

  15. Comparative experiment of four different materials as carriers of Bone morphogenetic protein to repair long bone defect

    Institute of Scientific and Technical Information of China (English)

    WEI Kuan-hai; PEI Guo-xian; YANG Run-gong

    2001-01-01

    @@ OBJECTIVE To investigate the effects of four different materials as carriers of bone morphogenetic protein (BMP) to repair long bone defect. METHODS 12 mm radius bone defects were made. They were divided into 4 groups in random and repaired respectively with the vascular muscle flap combined with FS/BMP (group A), vascular muscle flap/BMP (group B), bloodless muscle flap/BMP (group C) and autolyzed antigen-extracted allogeneic bone (AAA)/BMP (group D).Their abilities of bone forming to repair bone defects were observed.

  16. Property Status of Lunar Material

    Science.gov (United States)

    Pop, V.

    Most of the lunar material in private hands is of meteoric origin, and its property sta- tus does not present many challenges. The intention of Applied Space Resources, Inc, to fly a commercial lunar sample return mission and to subsequently offer lunar ma- terial for sale, raises the issue of the legality of exploitation and private ownership of retrieved lunar material. Lunar samples have been returned in the past by means of the Apollo (US) and Luna (USSR) missions and, while most of the material re- mains government property and is used for scientific means, a small fraction has been transferred abroad and some has entered the private market. Apollo-collected moon- rocks have been offered, symbolically, to heads of States, and some foreign nations have subsequently transferred ownership to private individuals. The same, lunar ma- terial of Soviet provenience has entered the private market, this forming a valuable legal precedent for the lawfulness of sale of lunar material. Recently, plans were made public to award the Apollo astronauts with lunar rocks. While in the US there is a popular misconception that it is illegal to own lunar material, the truth lies elsewhere. As the Apollo samples are the property of the US government and a small fraction was stolen, lost, or misplaced, the US government intends to recover this material, unlawfully owned. In the same time, a significant number of individuals have been prosecuted for offering for sale fake lunar rocks. The present paper will analyse the different categories of lunar material according to its ownership status, and will as- sert that private property of lunar material is lawful, and lunar material that will be returned in the future will be able to enter the market without hindrances.

  17. I. The metabolic properties of plutonium and allied materials

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, J.G.

    1948-05-24

    This report on the metabolic properties of plutonium and related radioactive materials presents experimental information in the following areas: radioautographic studies; tracer studies (with tables of accumulation in tissues) of actinium, radio-zirconium, technetium, radio-rubidium, radio-germanium, beryllium, and cadmium; decontamination and bone metabolism studies; and radio-chemical isolation.

  18. Electrical and dielectric properties of bovine trabecular bone - relationships with mechanical properties and mineral density

    International Nuclear Information System (INIS)

    Interrelationships of trabecular bone electrical and dielectric properties with mechanical characteristics and density are poorly known. While electrical stimulation is used for healing fractures, better understanding of these relations has clinical importance. Furthermore, earlier studies have suggested that bone electrical and dielectric properties depend on the bone density and could, therefore, be used to predict bone strength. To clarify these issues, volumetric bone mineral density (BMDvol), electrical and dielectric as well as mechanical properties were determined from 40 cylindrical plugs of bovine trabecular bone. Phase angle, relative permittivity, loss factor and conductivity of wet bovine trabecular bone were correlated with Young's modulus, yield stress, ultimate strength, resilience and BMDvol. The reproducibility of in vitro electrical and dielectric measurements was excellent (standardized coefficient of variation less than 1%, for all parameters), especially at frequencies higher than 1 kHz. Correlations of electrical and dielectric parameters with the bone mechanical properties or density were frequency-dependent. The relative permittivity showed the strongest linear correlations with mechanical parameters (r > 0.547, p vol (r 0.866, p vol were highest at frequencies over 6 kHz. In addition, a significant site-dependent variation of electrical and dielectric characteristics, mechanical properties and BMDvol was revealed in bovine femur (p < 0.05, Kruskall-Wallis H-test). Based on the present results, we conclude that the measurement of electrical and dielectric properties provides quantitative information that is related to bone quantity and quality

  19. A new Fe-Mn-Si alloplastic biomaterial as bone grafting material: In vivo study

    Science.gov (United States)

    Fântânariu, Mircea; Trincă, Lucia Carmen; Solcan, Carmen; Trofin, Alina; Strungaru, Ştefan; Şindilar, Eusebiu Viorel; Plăvan, Gabriel; Stanciu, Sergiu

    2015-10-01

    Designing substrates having suitable mechanical properties and targeted degradation behavior is the key's development of bio-materials for medical application. In orthopedics, graft material may be used to fill bony defects or to promote bone formation in osseous defects created by trauma or surgical intervention. Incorporation of Si may increase the bioactivity of implant locally, both by enhancing interactions at the graft-host interface and by having a potential endocrine like effect on osteoblasts. A Fe-Mn-Si alloy was obtained as alloplastic graft materials for bone implants that need long recovery time period. The surface morphology of the resulted specimens was investigated using scanning electrons microscopy (VegaTescan LMH II, SE detector, 30 kV), X-ray diffractions (X'Pert equipment) or X-ray dispersive energy analyze (Bruker EDS equipment). This study objective was to evaluate in vivo the mechanisms of degradation and the effects of its implantation over the main metabolic organs. Biochemical, histological, plain X radiography and computed tomography investigations showed good compatibility of the subcutaneous implants in the rat organism. The implantation of the Fe-Mn-Si alloy, in critical size bone (tibiae) defect rat model, did not induced adverse biological reactions and provided temporary mechanical support to the affected bone area. The biodegradation products were hydroxides layers which adhered to the substrate surface. Fe-Mn-Si alloy assured the mechanical integrity in rat tibiae defects during bone regeneration.

  20. Prediction of trabecular bone qualitative properties using scanning quantitative ultrasound

    Science.gov (United States)

    Qin, Yi-Xian; Lin, Wei; Mittra, Erik; Xia, Yi; Cheng, Jiqi; Judex, Stefan; Rubin, Clint; Müller, Ralph

    2013-11-01

    Microgravity induced bone loss represents a critical health problem in astronauts, particularly occurred in weight-supporting skeleton, which leads to osteopenia and increase of fracture risk. Lack of suitable evaluation modality makes it difficult for monitoring skeletal status in long term space mission and increases potential risk of complication. Such disuse osteopenia and osteoporosis compromise trabecular bone density, and architectural and mechanical properties. While X-ray based imaging would not be practical in space, quantitative ultrasound may provide advantages to characterize bone density and strength through wave propagation in complex trabecular structure. This study used a scanning confocal acoustic diagnostic and navigation system (SCAN) to evaluate trabecular bone quality in 60 cubic trabecular samples harvested from adult sheep. Ultrasound image based SCAN measurements in structural and strength properties were validated by μCT and compressive mechanical testing. This result indicated a moderately strong negative correlations observed between broadband ultrasonic attenuation (BUA) and μCT-determined bone volume fraction (BV/TV, R2=0.53). Strong correlations were observed between ultrasound velocity (UV) and bone's mechanical strength and structural parameters, i.e., bulk Young's modulus (R2=0.67) and BV/TV (R2=0.85). The predictions for bone density and mechanical strength were significantly improved by using a linear combination of both BUA and UV, yielding R2=0.92 for BV/TV and R2=0.71 for bulk Young's modulus. These results imply that quantitative ultrasound can characterize trabecular structural and mechanical properties through measurements of particular ultrasound parameters, and potentially provide an excellent estimation for bone's structural integrity.

  1. Electrical and dielectric properties of bovine trabecular bone - relationships with mechanical properties and mineral density

    Science.gov (United States)

    Sierpowska, J.; Töyräs, J.; Hakulinen, M. A.; Saarakkala, S.; Jurvelin, J. S.; Lappalainen, R.

    2003-03-01

    Interrelationships of trabecular bone electrical and dielectric properties with mechanical characteristics and density are poorly known. While electrical stimulation is used for healing fractures, better understanding of these relations has clinical importance. Furthermore, earlier studies have suggested that bone electrical and dielectric properties depend on the bone density and could, therefore, be used to predict bone strength. To clarify these issues, volumetric bone mineral density (BMDvol), electrical and dielectric as well as mechanical properties were determined from 40 cylindrical plugs of bovine trabecular bone. Phase angle, relative permittivity, loss factor and conductivity of wet bovine trabecular bone were correlated with Young's modulus, yield stress, ultimate strength, resilience and BMDvol. The reproducibility of in vitro electrical and dielectric measurements was excellent (standardized coefficient of variation less than 1%, for all parameters), especially at frequencies higher than 1 kHz. Correlations of electrical and dielectric parameters with the bone mechanical properties or density were frequency-dependent. The relative permittivity showed the strongest linear correlations with mechanical parameters (r > 0.547, p femur (p < 0.05, Kruskall-Wallis H-test). Based on the present results, we conclude that the measurement of electrical and dielectric properties provides quantitative information that is related to bone quantity and quality.

  2. Tof-Sims Application for Evaluating the Atomic Structure of New Bone Substitute Material

    Science.gov (United States)

    Oteri, G.; Pisanom, M.; Cicciù, M.

    2016-05-01

    The aim of this experimental study is to evaluate, in vitro, the chemical composition and the micromorphological structure of a bone substitute material surface. This material is based on calcium triphosphate and hydroxyapatite microgranules. Some results of a preliminary surface study of the above mentioned bioceramic materials are reported. The study has been carried out by means of time-of-flight secondary ion mass spectrometry (TOF-SIMS), complemented by X-ray photoelectron spectrometry (XPS) measurements. Whereas XPS data supplies the average surface composition of the system, TOF-SIMS supplies laterally and depth resolved information on the sample. This preliminary study confirms the properties of osteoconduction and scaffold features of the material. Moreover, a possible osteoinductive capability could be due to the presence of surface micropores, which could help in the attraction of bone morphogenetic protein (BMP), thus promoting the osteogenesis.

  3. Mechanical Properties of Composite Materials

    Directory of Open Access Journals (Sweden)

    Mitsuhiro Okayasu

    2014-10-01

    Full Text Available An examination has been made of the mechanical and failure properties of several composite materials, such as a short and a long carbon fiber reinforced plastic (short- and long-CFRP and metal based composite material. The short CFRP materials were used for a recycled CFRP which fabricated by the following process: the CFRP, consisting of epoxy resin with carbon fiber, is injected to a rectangular plate cavity after mixing with acrylonitrile butadiene styrene resin with different weight fractions of CFRP. The fatigue and ultimate tensile strength (UTS increased with increasing CFRP content. These correlations, however, break down, especially for tensile strength, as the CFPR content becomes more than 70%. Influence of sample temperature on the bending strength of the long-CFRP was investigated, and it appears that the strength slightly decreases with increasing the temperature, due to the weakness in the matrix. Broken fiber and pull-out or debonding between the fiber and matrix were related to the main failure of the short- and long-CFRP samples. Mechanical properties of metal based composite materials have been also investigated, where fiber-like high hardness CuAl2 structure is formed in aluminum matrix. Excellent mechanical properties were obtained in this alloy, e.g., the higher strength and the higher ductility, compared tothe same alloy without the fiber-like structure. There are strong anisotropic effects on the mechanical properties due to the fiber-like metal composite in a soft Al based matrix.

  4. Modern materials in fabrication of scaffolds for bone defect replacement

    Science.gov (United States)

    Bazlov, V. A.; Mamuladze, T. Z.; Pavlov, V. V.; Kirilova, I. A.; Sadovoy, M. A.

    2016-08-01

    The article defines the requirements for modern scaffold-forming materials and describes the main advantages and disadvantages of various synthetic materials. Osseointegration of synthetic scaffolds approved for use in medical practice is evaluated. Nylon 618 (certification ISO9001 1093-1-2009) is described as the most promising synthetic material used in medical practice. The authors briefly highlight the issues of individual bone grafting with the use of 3D printing technology. An example of contouring pelvis defect after removal of a giant tumor with the use of 3D models is provided.

  5. Antibacterial and osteoinductive properties of demineralized bone matrix treated with silver

    International Nuclear Information System (INIS)

    The problems incurred by storage of demineralized bone allograft material and its potential use in contaminated operative sites make an antibacterial property desirable. Silver was considered for this role because of its wide spectrum of antibacterial susceptibility, low incidence of resistance, and its ability to persistently inhibit bacteria after binding to collagen matrices. Demineralized bone matrix prepared from rat diaphyseal bone segments was treated by exposure fo AgCl, AgNO3 and NaNO3 solutions prior to lyophilization. The resulting material was tested for bacterial inhibition after incubation in saline solutions for various times and showed inhibition persisting for at least four weeks (Ag-treated material only). Silver treating the matrix was found to partially inhibit the osteoinductive capacity at 10(-3) and 10(-2) M but not at 10(-5) M as measured by intramuscular implantation in the rat for six weeks. Control and NaNo3-treated specimens showed normal bone growth as measured by ashing and by 99mTc binding, and confirmed by radiologic densities. Histologic sections showed dense microdeposits on dense material predominately near the decalcified bone surfaces, but also within the matrix. The results suggest that pretreatment with silver at concentrations in the 10(-4) range would render the implant material antibacterial, protect its sterility, and leave the osteoinductive capacity intact

  6. Antibacterial and osteoinductive properties of demineralized bone matrix treated with silver

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, S.J.; Spadaro, J.A.; Webster, D.A.

    The problems incurred by storage of demineralized bone allograft material and its potential use in contaminated operative sites make an antibacterial property desirable. Silver was considered for this role because of its wide spectrum of antibacterial susceptibility, low incidence of resistance, and its ability to persistently inhibit bacteria after binding to collagen matrices. Demineralized bone matrix prepared from rat diaphyseal bone segments was treated by exposure fo AgCl, AgNO3 and NaNO3 solutions prior to lyophilization. The resulting material was tested for bacterial inhibition after incubation in saline solutions for various times and showed inhibition persisting for at least four weeks (Ag-treated material only). Silver treating the matrix was found to partially inhibit the osteoinductive capacity at 10(-3) and 10(-2) M but not at 10(-5) M as measured by intramuscular implantation in the rat for six weeks. Control and NaNo3-treated specimens showed normal bone growth as measured by ashing and by 99mTc binding, and confirmed by radiologic densities. Histologic sections showed dense microdeposits on dense material predominately near the decalcified bone surfaces, but also within the matrix. The results suggest that pretreatment with silver at concentrations in the 10(-4) range would render the implant material antibacterial, protect its sterility, and leave the osteoinductive capacity intact.

  7. Bone Replacement Materials and Techniques Used for Achieving Vertical Alveolar Bone Augmentation

    Directory of Open Access Journals (Sweden)

    Zeeshan Sheikh

    2015-05-01

    Full Text Available Alveolar bone augmentation in vertical dimension remains the holy grail of periodontal tissue engineering. Successful dental implant placement for restoration of edentulous sites depends on the quality and quantity of alveolar bone available in all spatial dimensions. There are several surgical techniques used alone or in combination with natural or synthetic graft materials to achieve vertical alveolar bone augmentation. While continuously improving surgical techniques combined with the use of auto- or allografts provide the most predictable clinical outcomes, their success often depends on the status of recipient tissues. The morbidity associated with donor sites for auto-grafts makes these techniques less appealing to both patients and clinicians. New developments in material sciences offer a range of synthetic replacements for natural grafts to address the shortcoming of a second surgical site and relatively high resorption rates. This narrative review focuses on existing techniques, natural tissues and synthetic biomaterials commonly used to achieve vertical bone height gain in order to successfully restore edentulous ridges with implant-supported prostheses.

  8. Influence of interfacial properties and inhomogeneity on formation of microdamage in bone

    Science.gov (United States)

    Nakade, Rugved

    Microdamage accumulation at the nanoscopic level of bone affects the overall mechanical behavior of the bone. This makes it necessary to study the mechanisms through which microdamage accumulation can take place at the nanoscopic level. Experiments on bone's different hierarchy are difficult because of the small sizes of these hierarchical structures. Prevention of bone fractures is greatly enhanced with the help of predictive computational tools and hence used to evaluate the effects of microdamage in bone. There are two main types of microdamage that can form in the bone; linear cracks and diffuse damage. The bone nanostructure consists of mineral platelets embedded in soft protein called collagen and can be treated as a composite material. In this study, a two-dimensional probabilistic finite element model of the bone nanostructure was developed to evaluate the likely formation of the microdamage in the nanostructure due to changes in material properties of the nanostructure. The influence of the microdamage formation due to the collagen-mineral interface strength and also the effects of inhomogeneity were studied. To study interfacial strength effects, cohesive elements using bilinear traction separation laws were used to simulate the behavior of the interface (by way of interfacial debonding) between the collegen-mineral layers. Random field theory was used to assign spatially correlated random variables in order to assign inhomogeneous material properties to the bone. Correlation lengths were used to control the level of inhomogeneity in the model. The analysis showed that the type of microdamage was significantly influenced by the strength of the mineral-collagen interface. Probabilistic failure analyses indicated that strong interfaces resulted in limited interfacial debonding and narrow stress concentrations around an initial defect in the mineral-collagen composite, thereby suggesting that the likely location of failure was in same plane of the initial

  9. PCL-coated hydroxyapatite scaffold derived from cuttlefish bone: morphology, mechanical properties and bioactivity.

    Science.gov (United States)

    Milovac, Dajana; Gallego Ferrer, Gloria; Ivankovic, Marica; Ivankovic, Hrvoje

    2014-01-01

    In the present study, poly(ε-caprolactone)-coated hydroxyapatite scaffold derived from cuttlefish bone was prepared. Hydrothermal transformation of aragonitic cuttlefish bone into hydroxyapatite (HAp) was performed at 200°C retaining the cuttlebone architecture. The HAp scaffold was coated with a poly(ε-caprolactone) (PCL) using vacuum impregnation technique. The compositional and morphological properties of HAp and PCL-coated HAp scaffolds were studied by means of X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis. Bioactivity was tested by immersion in Hank's balanced salt solution (HBSS) and mechanical tests were performed at compression. The results showed that PCL-coated HAp (HAp/PCL) scaffold resulted in a material with improved mechanical properties that keep the original interconnected porous structure indispensable for tissue growth and vascularization. The compressive strength (0.88MPa) and the elastic modulus (15.5MPa) are within the lower range of properties reported for human trabecular bones. The in vitro mineralization of calcium phosphate (CP) that produces the bone-like apatite was observed on both the pure HAp scaffold and the HAp/PCL composite scaffold. The prepared bioactive scaffold with enhanced mechanical properties is a good candidate for bone tissue engineering applications. PMID:24268280

  10. PCL-coated hydroxyapatite scaffold derived from cuttlefish bone: Morphology, mechanical properties and bioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Milovac, Dajana, E-mail: dmilovac@fkit.hr [Faculty of Chemical Engineering and Technology, University of Zagreb (Croatia); Gallego Ferrer, Gloria [Center for Biomaterials and Tissue Engineering, Polytechnic University of Valencia (Spain); Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) (Spain); Ivankovic, Marica; Ivankovic, Hrvoje [Faculty of Chemical Engineering and Technology, University of Zagreb (Croatia)

    2014-01-01

    In the present study, poly(ε-caprolactone)-coated hydroxyapatite scaffold derived from cuttlefish bone was prepared. Hydrothermal transformation of aragonitic cuttlefish bone into hydroxyapatite (HAp) was performed at 200 °C retaining the cuttlebone architecture. The HAp scaffold was coated with a poly(ε-caprolactone) (PCL) using vacuum impregnation technique. The compositional and morphological properties of HAp and PCL-coated HAp scaffolds were studied by means of X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis. Bioactivity was tested by immersion in Hank's balanced salt solution (HBSS) and mechanical tests were performed at compression. The results showed that PCL-coated HAp (HAp/PCL) scaffold resulted in a material with improved mechanical properties that keep the original interconnected porous structure indispensable for tissue growth and vascularization. The compressive strength (0.88 MPa) and the elastic modulus (15.5 MPa) are within the lower range of properties reported for human trabecular bones. The in vitro mineralization of calcium phosphate (CP) that produces the bone-like apatite was observed on both the pure HAp scaffold and the HAp/PCL composite scaffold. The prepared bioactive scaffold with enhanced mechanical properties is a good candidate for bone tissue engineering applications. - Highlights: • Hydroxyapatite/poly(ε-caprolactone) scaffolds with interconnected pores were prepared. • Hydrothermal transformation of cuttlefish bone and vacuum impregnation were used. • A material with improved mechanical properties was obtained. • The in vitro mineralization of calcium phosphate was observed.

  11. PCL-coated hydroxyapatite scaffold derived from cuttlefish bone: Morphology, mechanical properties and bioactivity

    International Nuclear Information System (INIS)

    In the present study, poly(ε-caprolactone)-coated hydroxyapatite scaffold derived from cuttlefish bone was prepared. Hydrothermal transformation of aragonitic cuttlefish bone into hydroxyapatite (HAp) was performed at 200 °C retaining the cuttlebone architecture. The HAp scaffold was coated with a poly(ε-caprolactone) (PCL) using vacuum impregnation technique. The compositional and morphological properties of HAp and PCL-coated HAp scaffolds were studied by means of X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis. Bioactivity was tested by immersion in Hank's balanced salt solution (HBSS) and mechanical tests were performed at compression. The results showed that PCL-coated HAp (HAp/PCL) scaffold resulted in a material with improved mechanical properties that keep the original interconnected porous structure indispensable for tissue growth and vascularization. The compressive strength (0.88 MPa) and the elastic modulus (15.5 MPa) are within the lower range of properties reported for human trabecular bones. The in vitro mineralization of calcium phosphate (CP) that produces the bone-like apatite was observed on both the pure HAp scaffold and the HAp/PCL composite scaffold. The prepared bioactive scaffold with enhanced mechanical properties is a good candidate for bone tissue engineering applications. - Highlights: • Hydroxyapatite/poly(ε-caprolactone) scaffolds with interconnected pores were prepared. • Hydrothermal transformation of cuttlefish bone and vacuum impregnation were used. • A material with improved mechanical properties was obtained. • The in vitro mineralization of calcium phosphate was observed

  12. 'Universal' microstructural patterns in cortical and trabecular, extracellular and extravascular bone materials: micromechanics-based prediction of anisotropic elasticity.

    Science.gov (United States)

    Fritsch, Andreas; Hellmich, Christian

    2007-02-21

    Bone materials are characterized by an astonishing variability and diversity. Still, because of 'architectural constraints' due to once chosen material constituents and their physical interaction, the fundamental hierarchical organization or basic building plans of bone materials remain largely unchanged during biological evolution. Such universal patterns of microstructural organization govern the mechanical interaction of the elementary components of bone (hydroxyapatite, collagen, water; with directly measurable tissue-independent elastic properties), which are here quantified through a multiscale homogenization scheme delivering effective elastic properties of bone materials: at a scale of 10nm, long cylindrical collagen molecules, attached to each other at their ends by approximately 1.5nm long crosslinks and hosting intermolecular water inbetween, form a contiguous matrix called wet collagen. At a scale of several hundred nanometers, wet collagen and mineral crystal agglomerations interpenetrate each other, forming the mineralized fibril. At a scale of 5-10microm, the extracellular solid bone matrix is represented as collagen fibril inclusions embedded in a foam of largely disordered (extrafibrillar) mineral crystals. At a scale above the ultrastructure, where lacunae are embedded in extracellular bone matrix, the extravascular bone material is observed. Model estimates predicted from tissue-specific composition data gained from a multitude of chemical and physical tests agree remarkably well with corresponding acoustic stiffness experiments across a variety of cortical and trabecular, extracellular and extravascular materials. Besides from reconciling the well-documented, seemingly opposed concepts of 'mineral-reinforced collagen matrix' and 'collagen-reinforced mineral matrix' for bone ultrastructure, this approach opens new possibilities in the exploitation of computer tomographic data for nano-to-macro mechanics of bone organs. PMID:17074362

  13. Mineralized polymer composites as biogenic bone substitute material

    Science.gov (United States)

    Shah, Rushita; Saha, Nabanita; Kitano, Takeshi; Saha, Petr

    2015-05-01

    Mineralized polymer composites (MPC) are recognized as potential fillers of bone defects. Though bioceramics exhibits quite a good bone-bonding and vascularization, it is considered to be too stiff and brittle for using alone. Thus, the use of polymer scaffold instead of bioceramics has several advantages including combining the osteoconductivity and bone-bonding potential of the inorganic phase with the porosity and interconnectivity of the three-dimensional construction. Aiming the advantages of ceramic-polymer composite scaffolds, the calcium carbonate (CaCO3) based biomineralized scaffold was prepared, where the PVP-CMC hydrogel was used as an extracellular matrix. This paper is reported about the morphology, swelling trend (in physiological solution) and viscoelastic behavior of (90 min mineralized) MPC. The dry MPC are off-white, coarse in texture, comparatively less flexible than the original PVP-CMC based hydrogel film, and the deposition of granular structures on the surface of the hydrogel film confirms about the development of biomineralized scaffold/polymer composites. Irrespective of thickness, the dry MPC shows higher values of swelling ratio within 30 min, which varies between 200-250 approximately. The dynamic viscoelastic nature of freshly prepared MPC was investigated applying 1% and 10% strain. At higher strain the viscoelastic moduli (G' and G") show significant change, and the nature of MPC turns from elastic to viscous. Based on the observed basic properties, the MPC (calcite based polymer composites) can be recommended for the treatment of adyanamic bone disorder.

  14. Mechanical properties of femoral trabecular bone in dogs

    Directory of Open Access Journals (Sweden)

    Nolte Ingo

    2005-03-01

    Full Text Available Abstract Background Studying mechanical properties of canine trabecular bone is important for a better understanding of fracture mechanics or bone disorders and is also needed for numerical simulation of canine femora. No detailed data about elastic moduli and degrees of anisotropy of canine femoral trabecular bone has been published so far, hence the purpose of this study was to measure the elastic modulus of trabecular bone in canine femoral heads by ultrasound testing and to assess whether assuming isotropy of the cancellous bone in femoral heads in dogs is a valid simplification. Methods From 8 euthanized dogs, both femora were obtained and cubic specimens were cut from the centre of the femoral head which were oriented along the main pressure and tension trajectories. The specimens were tested using a 100 MHz ultrasound transducer in all three orthogonal directions. The directional elastic moduli of trabecular bone tissue and degrees of anisotropy were calculated. Results The elastic modulus along principal bone trajectories was found to be 11.2 GPa ± 0.4, 10.5 ± 2.1 GPa and 10.5 ± 1.8 GPa, respectively. The mean density of the specimens was 1.40 ± 0.09 g/cm3. The degrees of anisotropy revealed a significant inverse relationship with specimen densities. No significant differences were found between the elastic moduli in x, y and z directions, suggesting an effective isotropy of trabecular bone tissue in canine femoral heads. Discussion This study presents detailed data about elastic moduli of trabecular bone tissue obtained from canine femoral heads. Limitations of the study are the relatively small number of animals investigated and the measurement of whole specimen densities instead of trabecular bone densities which might lead to an underestimation of Young's moduli. Publications on elastic moduli of trabecular bone tissue present results that are similar to our data. Conclusion This study provides data about directional elastic

  15. Relationship between nanoscale mineral properties and calcein labeling in mineralizing bone surfaces

    OpenAIRE

    Aido, Marta; Kerschnitzki, Michael; Hoerth, Rebecca; Burghammer, Manfred; Montero, Cédric; Checa, Sara; Fratzl, Peter; Duda, Georg; Willie, Bettina; Wagermaier, Wolfgang

    2014-01-01

    Bone's mineral properties, such as particle thickness and degree of alignment have been associated with bone quality. Bone formation, remodeling, aging of the tissue and mineral homeostasis influence mineral particle properties leading to specific patterns across bone. Scanning small angle X-ray scattering (sSAXS) with synchrotron radiation is a powerful tool, which allows us to study bone's nanoscale mineral properties in a position-resolved way. We used sSAXS, fluorescence light microscopy ...

  16. Cell response of calcium phosphate based ceramics, a bone substitute material

    Directory of Open Access Journals (Sweden)

    Juliana Marchi

    2013-01-01

    Full Text Available The aim of this study was to characterize calcium phosphate ceramics with different Ca/P ratios and evaluate cell response of these materials for use as a bone substitute. Bioceramics consisting of mixtures of hydroxyapatite (HAp and β-tricalcium phosphate (β-TCP powders in different proportions were pressed and sintered. The physical and chemical properties of these bioceramics were then characterized. Characterization of the biological properties of these materials was based on analysis of cell response using cultured fibroblasts. The number of cells attached to the samples was counted from SEM images of samples exposed to cell culture solution for different periods. These data were compared by analysis of variance (ANOVA complemented by the Tukey's test. The TCP sample had higher surface roughness and lower density. The adherence and growth of FMM1 cells on samples from all groups was studied. Even though the different calcium based ceramics exhibited properties which made them suitable as bone substitutes, those with higher levels of β-TCP revealed improved cell growth on their surfaces. These observations indicated two-phase calcium phosphate based materials with a β-TCP surface layer to be a promising bone substitute.

  17. Material properties of oxide superconductors

    International Nuclear Information System (INIS)

    The differences between the old (inter-) metallic superconductors and the new oxide superconductors are not limited to the much higher values of Tc attainable in the latter. There are many pervasive differences caused directly by oxide chemistry, quasi-perovskite local coordination configurations, and layered metal-semiconductor-metal'-semiconductor-structures. When these differences are ignored, for instance in theoretical models which make effective medium approximations, many experiments appear to present anomalous results. These anomalies largely disappear when account is taken of the real materials properties of the cuprates and other new oxide superconductors, for instance in theoretical models which treat transport as a partially percolative process. This percolative process directly reflects the fact that the highest values of Tc, as well as the most anomalous normal-state transport properties, occur in materials vicinal to a metal-insulator transition. As the metallic and insulating regions alternate even in single-crystal samples, effective medium models, and most effective-medium parameters, lose their significance. Examples of attempts to measure microscopic properties illustrate the importance of filamentary effects on both normal-state and superconductive properties

  18. Nonlinear Optical Properties of Materials

    CERN Document Server

    Ganeev, Rashid A

    2013-01-01

    This book is mostly concerned on the experimental research of the nonlinear optical characteristics of various media, low- and high-order harmonic generation in different materials, and formation, and nonlinear optical characterization of clusters. We also demonstrate the inter-connection between these areas of nonlinear optics.   Nonlinear optical properties of media such as optical limiting can be applied in various areas of science and technology. To define suitable materials for these applications, one has to carefully analyse the nonlinear optical characteristics of various media, such as the nonlinear refractive indices, coefficients of nonlinear absorption, saturation absorption intensities, etc. Knowing the nonlinear optical parameters of materials is also important for describing the propagation effects, self-interaction of intense laser pulses, and optimisation of various nonlinear optical processes. Among those processes one can admit the importance of the studies of the frequency conversion of c...

  19. Interrelationships between densitometric, geometric, and mechanical properties of rat femora: inferences concerning mechanical regulation of bone modeling.

    Science.gov (United States)

    Ferretti, J L; Capozza, R F; Mondelo, N; Zanchetta, J R

    1993-11-01

    A compensation for differences in bone material quality by bone geometric properties in femora from two different strains of rats was previously shown by us. A feedback mechanism controlling the mechanical properties of the integrated bones was then proposed, in accordance with Frost's mechanostat theory. Evidence of such a system is now offered by the finding of a negative correlation between the modeling-dependent cross-sectional architecture (moment of inertia) and the mineral-dependent stiffness (elastic modulus) of bone material in the femoral diaphyses of 45 normal Wistar rats of different sexes, ages, and sizes. The strength and stiffness of the integrated diaphyses were found to depend on both cross-sectional inertia and body weight, not on bone mineral density. These findings are interpreted as supporting the hypothesis that the architectural efficiency of diaphyseal cross-sectional design resulting from the spatial orientation of bone modeling during growth is optimized as a function of the body weight-dependent bone strain history, within the constraints imposed by bone stiffness. Results suggest a modulating role of biomass, related to the system set point determination, and explain the usually observed lack of a direct correlation between mineral density and strength or stiffness of long bones in studies of geometrically inhomogeneous populations. PMID:8266830

  20. Electrical and dielectric properties of bovine trabecular bone - relationships with mechanical properties and mineral density

    Energy Technology Data Exchange (ETDEWEB)

    Sierpowska, J [Department of Applied Physics, University of Kuopio, POB 1627, 70211 Kuopio (Finland); Toeyraes, J [Department of Applied Physics, University of Kuopio, POB 1627, 70211 Kuopio (Finland); Hakulinen, M A [Department of Surgery, Kuopio University Hospital, POB 1777, 70211 Kuopio (Finland); Saarakkala, S [Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital and University of Kuopio, POB 1777, 70211 Kuopio (Finland); Jurvelin, J S [Department of Applied Physics, University of Kuopio, POB 1627, 70211 Kuopio (Finland); Lappalainen, R [Department of Applied Physics, University of Kuopio, POB 1627, 70211 Kuopio (Finland)

    2003-03-21

    Interrelationships of trabecular bone electrical and dielectric properties with mechanical characteristics and density are poorly known. While electrical stimulation is used for healing fractures, better understanding of these relations has clinical importance. Furthermore, earlier studies have suggested that bone electrical and dielectric properties depend on the bone density and could, therefore, be used to predict bone strength. To clarify these issues, volumetric bone mineral density (BMD{sub vol}), electrical and dielectric as well as mechanical properties were determined from 40 cylindrical plugs of bovine trabecular bone. Phase angle, relative permittivity, loss factor and conductivity of wet bovine trabecular bone were correlated with Young's modulus, yield stress, ultimate strength, resilience and BMD{sub vol}. The reproducibility of in vitro electrical and dielectric measurements was excellent (standardized coefficient of variation less than 1%, for all parameters), especially at frequencies higher than 1 kHz. Correlations of electrical and dielectric parameters with the bone mechanical properties or density were frequency-dependent. The relative permittivity showed the strongest linear correlations with mechanical parameters (r > 0.547, p < 0.01, n = 40, at 50 kHz) and with BMD{sub vol} (r 0.866, p < 0.01, n = 40, at 50 kHz). In general, linear correlations between relative permittivity and mechanical properties or BMD{sub vol} were highest at frequencies over 6 kHz. In addition, a significant site-dependent variation of electrical and dielectric characteristics, mechanical properties and BMD{sub vol} was revealed in bovine femur (p < 0.05, Kruskall-Wallis H-test). Based on the present results, we conclude that the measurement of electrical and dielectric properties provides quantitative information that is related to bone quantity and quality.

  1. Dynamic behavior and microstructural properties of cancellous bone

    CERN Document Server

    Laporte, Sébastien; Bousson, Valérie; Pattofatto, Stephane

    2009-01-01

    The aim of the presented study is to identify some properties of the dynamic behavior of the cancellous bone and to identify the link between this mechanical behavior and the microstructural properties. 7 cylinders of bovine cancellous bone (diameter 41 mm, thickness 14 mm) were tested in quasi static loading (0.001 s-1), 8 in dynamic loading (1000 s-1) and 10 in dynamic loading (1500 s-1) with a confinement system. All the specimens were submitted to imaging before the tests (pQCT) in order to indentify two microstructural properties: Bone Volume / Total Volume ? BV/TV ? and Trabeculae Thickness ? Tb.Th. The behavior of bovine cancellous bone under compression exhibits a foam-type behavior over the whole range of strain rates explored in this study. The results show that for the quasi-static tests only the stresses are correlated with BV/TV. For the unconfined dynamic tests, the yield stress is correlated to BV/TV and the plateau stress to BV/TV and Tb.Th. For the confined tests, only the plateau stress is c...

  2. Use of osteoplastic material to guide bone tissue regeneration deffect.

    Science.gov (United States)

    Machavariani, A; Mazmishvili, K; Grdzelidze, T; Menabde, G; Amiranashvili, I

    2011-12-01

    The goal of research was study of restoration processes in jaw-teeth bone defects by application of osteoplastic materials in the experiment. The experiment was performed over 32 white (6-12 month old) rats; the animals were divided into 2 groups; 16 animals were enrolled in the first group; the section was performed in the edge of lower jaw; the lower jaw body was revealed. Under the effect of the dental drilling machine and the # 1 cooling mean by the fissure bohrium (distilled water) the defect of the dimension of 2x2 mm was created; the defect was washed by 0/9% saline to remove the bone sawdust; the wound was sutured tightly, in layers. The second group of the experiment was staffed with 16 animals (main group); the similar bone defect of the size 2 x 2mm was created on the rat's jaw's body. After washing of modeled defect we inserted osteopathic materials PORESORB-TCP crystals with the size of 0,6-1.0 mm the wound was sutured tightly, in layers. After the 3-rd, 15-th, 30-th and 90-th days from the date of operation there was performed X-ray and morphological examination over the animals in the control as well as the main group. The analysis of the examination performed over the experimental materials showed that in the control group in samples taken at 90th day the defects were not completely restored. In the test group in samples taken at 90th day reparative regeneration is confirmed. This is stimulated by the factor that within the main group's animals the defect regeneration process is supported with the osteoplastic material PORESORB-TCP. PMID:22306506

  3. Mycobacterium tuberculosis Contaminant Risk on Bone Marrow Aspiration Material from Iliac Bone Patients with Active Tuberculous Spondylitis

    OpenAIRE

    Ahmad Jabir Rahyussalim; Tri Kurniawati; Andriansjah Rukmana

    2016-01-01

    There was a concern on Mycobacterium tuberculosis spreading to the bone marrow, when it was applied on tuberculous spine infection. This research aimed to study the probability of using autologous bone marrow as a source of mesenchymal stem cell for patients with tuberculous spondylitis. As many as nine patients with tuberculous spondylitis were used as samples. During the procedure, the vertebral lesion material and iliac bone marrow aspirates were obtained for acid fast staining, bacteria c...

  4. Interrelationships between electrical properties and microstructure of human trabecular bone

    Science.gov (United States)

    Sierpowska, J.; Hakulinen, M. A.; Töyräs, J.; Day, J. S.; Weinans, H.; Kiviranta, I.; Jurvelin, J. S.; Lappalainen, R.

    2006-10-01

    Microstructural changes, such as reduction of trabecular thickness and number, are characteristic signs of osteoporosis leading to diminished bone strength. Electrical and dielectric parameters might provide diagnostically valuable information on trabecular bone microstructure not extractable from bone mineral density measurements. In this study, structural properties of human trabecular bone samples (n = 26) harvested from the distal femur and proximal tibia were investigated using the computed microtomography (microCT) technique. Quantitative parameters, e.g. structural model index (SMI) or trabecular bone volume fraction (BV/TV), were calculated. In addition, the samples were examined electrically over a wide frequency range (50 Hz-5 MHz) using a two-electrode impedance spectroscopy set-up. Relative permittivity, loss factor, conductivity, phase angle, specific impedance and dissipation factor were determined. Significant linear correlations were obtained between the dissipation factor and BV/TV or SMI (|r| >= 0.70, p < 0.01, n = 26). Principal component analyses, conducted on electrical and structural parameters, revealed that the high frequency principal component of the dissipation factor was significantly related to SMI (r = 0.72, p < 0.01, n = 26). The linear combination of high and low frequency relative permittivity predicted 73% of the variation in BV/TV. To conclude, electrical and dielectric parameters of trabecular bone, especially relative permittivity and dissipation factor, were significantly and specifically related to a trabecular microstructure as characterized with microCT. The data gathered in this study constitute a useful basis for theoretical and experimental work towards the development of impedance spectroscopy techniques for detection of bone quality in vitro or in special cases of open surgery.

  5. Interrelationships between electrical properties and microstructure of human trabecular bone

    Energy Technology Data Exchange (ETDEWEB)

    Sierpowska, J [Department of Physics, University of Kuopio, PO Box 1627, FI-70211 Kuopio (Finland); Hakulinen, M A [Department of Physics, University of Kuopio, PO Box 1627, FI-70211 Kuopio (Finland); Toeyraes, J [Department of Clinical Neurophysiology, Kuopio University Hospital and University of Kuopio, PO Box 1777, FI-70211 Kuopio (Finland); Day, J S [Erasmus Orthopaedic Research Laboratory, Erasmus MC EE1614, PO Box 1738, 3000 DR Rotterdam (Netherlands); Weinans, H [Erasmus Orthopaedic Research Laboratory, Erasmus MC EE1614, PO Box 1738, 3000 DR Rotterdam (Netherlands); Kiviranta, I [Department of Orthopaedics and Traumatology, Jyvaeskylae Central Hospital, Keskussairaalantie 19, FI-40620 Jyvaeskylae (Finland); Jurvelin, J S [Department of Physics, University of Kuopio, PO Box 1627, FI-70211 Kuopio (Finland); Lappalainen, R [Department of Physics, University of Kuopio, PO Box 1627, FI-70211 Kuopio (Finland)

    2006-10-21

    Microstructural changes, such as reduction of trabecular thickness and number, are characteristic signs of osteoporosis leading to diminished bone strength. Electrical and dielectric parameters might provide diagnostically valuable information on trabecular bone microstructure not extractable from bone mineral density measurements. In this study, structural properties of human trabecular bone samples (n = 26) harvested from the distal femur and proximal tibia were investigated using the computed microtomography (microCT) technique. Quantitative parameters, e.g. structural model index (SMI) or trabecular bone volume fraction (BV/TV), were calculated. In addition, the samples were examined electrically over a wide frequency range (50 Hz-5 MHz) using a two-electrode impedance spectroscopy set-up. Relative permittivity, loss factor, conductivity, phase angle, specific impedance and dissipation factor were determined. Significant linear correlations were obtained between the dissipation factor and BV/TV or SMI (vertical bar r vertical bar {>=} 0.70, p < 0.01, n = 26). Principal component analyses, conducted on electrical and structural parameters, revealed that the high frequency principal component of the dissipation factor was significantly related to SMI (r = 0.72, p < 0.01, n = 26). The linear combination of high and low frequency relative permittivity predicted 73% of the variation in BV/TV. To conclude, electrical and dielectric parameters of trabecular bone, especially relative permittivity and dissipation factor, were significantly and specifically related to a trabecular microstructure as characterized with microCT. The data gathered in this study constitute a useful basis for theoretical and experimental work towards the development of impedance spectroscopy techniques for detection of bone quality in vitro or in special cases of open surgery.

  6. Improved workability of injectable calcium sulfate bone cement by regulation of self-setting properties

    International Nuclear Information System (INIS)

    Calcium sulfate hemihydrate (CSH) powder as an injectable bone cement was prepared by hydrothermal synthesis of calcium sulfate dihydrate (CSD). The prepared materials showed X-ray diffraction peaks corresponding to the CSH structure without any secondary phases, implying complete conversion from CSD phase to CSH phase. Thermogravimetric (TG) analyses showed the crystal water content of CSH was about 6.0% (wt.), which is near to the theoretic crystal water value of CSH. From scanning electron microscopy (SEM) micrographs, sheet crystal structure of CSD was observed to transform into rod-like crystal structure of CSH. Most interesting and important of all, CSD as setting accelerator was also introduced into CSH powder to regulate self-setting properties of injectable CSH paste, and thus the self-setting time of CSH paste can be regulated from near 30 min to less than 5 min by adding various amounts of setting accelerator. Because CSD is not only the reactant of preparing CSH but also the final solidified product of CSH, the setting accelerator has no significant effect on the other properties of materials, such as mechanical properties. In vitro biocompatibility and in vivo histology studies have demonstrated that the materials have good biocompatibility and good efficacy in bone regeneration. All these will further improve the workability of CSH in clinic applications. Highlights: ► Calcium sulfate hemihydrate (CSH) can be an injectable bone cement. ► CSH was produced by hydrothermal synthesis of calcium sulfate dihydrate (CSD). ► CSD was introduced into CSH powder to regulate self-setting properties of CSH. ► Setting accelerator has no significant effect on the other properties of materials. ► Injectable CSH has good biocompatibility and good efficacy in bone regeneration

  7. Improved workability of injectable calcium sulfate bone cement by regulation of self-setting properties

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zonggang, E-mail: chenzg@sdu.edu.cn [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Liu, Huanye [Department of Orthodontics, School of Stomatology, China Medical University, Shenyang 110001 (China); Liu, Xi [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Lian, Xiaojie [College of Mechanics, Taiyuan University of Technology, Taiyuan 030024 (China); Guo, Zhongwu [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Jiang, Hong-Jiang [Wendeng Hospital of Traditional Chinese Orthopedics and Traumatology, Shandong 264400 (China); Cui, Fu-Zhai, E-mail: cuifz@mail.tsinghua.edu.cn [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2013-04-01

    Calcium sulfate hemihydrate (CSH) powder as an injectable bone cement was prepared by hydrothermal synthesis of calcium sulfate dihydrate (CSD). The prepared materials showed X-ray diffraction peaks corresponding to the CSH structure without any secondary phases, implying complete conversion from CSD phase to CSH phase. Thermogravimetric (TG) analyses showed the crystal water content of CSH was about 6.0% (wt.), which is near to the theoretic crystal water value of CSH. From scanning electron microscopy (SEM) micrographs, sheet crystal structure of CSD was observed to transform into rod-like crystal structure of CSH. Most interesting and important of all, CSD as setting accelerator was also introduced into CSH powder to regulate self-setting properties of injectable CSH paste, and thus the self-setting time of CSH paste can be regulated from near 30 min to less than 5 min by adding various amounts of setting accelerator. Because CSD is not only the reactant of preparing CSH but also the final solidified product of CSH, the setting accelerator has no significant effect on the other properties of materials, such as mechanical properties. In vitro biocompatibility and in vivo histology studies have demonstrated that the materials have good biocompatibility and good efficacy in bone regeneration. All these will further improve the workability of CSH in clinic applications. Highlights: ► Calcium sulfate hemihydrate (CSH) can be an injectable bone cement. ► CSH was produced by hydrothermal synthesis of calcium sulfate dihydrate (CSD). ► CSD was introduced into CSH powder to regulate self-setting properties of CSH. ► Setting accelerator has no significant effect on the other properties of materials. ► Injectable CSH has good biocompatibility and good efficacy in bone regeneration.

  8. Determination of reliable material properties

    International Nuclear Information System (INIS)

    As a result of the popularity of the Agencies report 'Neutron Irradiation Embrittlement of Reactor Pressure Vessel Steels' of 1975, it was decided that another report on this broad subject would be of use. In this report, background and contemporary views on specially identified areas of the subject are considered as self-contained chapters, written by experts. Chapter 5 is about the determination of reliable material properties. This concerns mainly mechanical test procedures and their interpretation. Some background concerning crack and fracture mechanisms is given

  9. The influence of lead on the biomechanical properties of bone tissue in rats

    Directory of Open Access Journals (Sweden)

    Grazyna Olchowik

    2014-06-01

    Full Text Available introduction and objective. Environmental lead (Pb is a serious public health problem. At high levels, Pb is devastating to almost all organs. On the other hand, it is difficult to determine a safe level of exposure to Pb. More than 90% of the Pb in the adult human body and 70% in a child’s body is stored in the bones. In the presented study, the effects of lead exposure on bones were studied for rats treated orally with Pb acetate in drinking water for 14 days. The hypothesis was tested that lead exposure negatively affects bone structure. materials and methods. Femur strength was measured in a three-point bending test, whereas infrared spectroscopy (FTIR was used to measure molecular structural changes. results. Lead significantly decreased the ratio of area of two types of vibrational transitions, which are highly specific to mineral to matrix ratio. The results of the biomechanical study show that femurs of rats treated by Pb-acetate appeared to be weaker than bones of the control group, and may produce a condition for the development of higher risk of fractures. Additionally, a great difference in body mass was observed between control and the Pb acetate-treated groups. conclusions. The lower bone mineral content and the weaker mechanical properties of bones from Pb-treated rats are associated with the pathologic state dependent of the exposure of lead.

  10. APPLICATION OF A BIODEGRADABLE MATERIAL FOR BONE REPLACEMENT IN TRAUMATOLOGY

    OpenAIRE

    T. V. Druzhinina; K. V. Trofimov; V. F. Naydanov; A. V. Rostovzev; D. V. Burkov; A. V. Zhulyabin; A. A. Isupov; A. V. Verevin

    2014-01-01

    20 men (medium age (31.5 ± 13.5) years) were studied. All patients underwent arthroscopic auditing plastic anterior cruciate ligament of the knee. Osteoregeneration dynamics were determined by biochemical testing of blood serum and X-ray computed tomography (CT) of the fracture in 1–4 months after surgery. As a result, an estimation of the bone tissue reparative regeneration according to CT data in 10 patients with a defect of the patella, treated with the material is provided. The obtained r...

  11. Tissue reaction and material characteristics of four bone substitutes

    DEFF Research Database (Denmark)

    Jensen, S S; Aaboe, M; Pinholt, E M; Hjørting-Hansen, E; Melsen, F; Ruyter, I E

    1996-01-01

    and Interpore 500 HA/CC) were implanted into 5-mm bur holes in rabbit tibiae. There was no difference in the amount of newly formed bone around the four biomaterials. Interpore 500 HA/CC resorbed completely, whereas the other three biomaterials did not undergo any detectable biodegradation. Bio......-Oss was osseointegrated to a higher degree than the other biomaterials. Material characteristics obtained by diffuse reflectance infrared Fourier transform spectrometry analysis and energy-dispersive spectrometry did not explain the differences in biologic behavior....

  12. Hard tissue regeneration using bone substitutes: an update on innovations in materials

    OpenAIRE

    Sarkar, Swapan Kumar; Lee, Byong Taek

    2015-01-01

    Bone is a unique organ composed of mineralized hard tissue, unlike any other body part. The unique manner in which bone can constantly undergo self-remodeling has created interesting clinical approaches to the healing of damaged bone. Healing of large bone defects is achieved using implant materials that gradually integrate with the body after healing is completed. Such strategies require a multidisciplinary approach by material scientists, biological scientists, and clinicians. Development o...

  13. Design, synthesis, and initial evaluation of D-glyceraldehyde crosslinked gelatin-hydroxyapatite as a potential bone graft substitute material

    Science.gov (United States)

    Florschutz, Anthony Vatroslav

    Utilization of bone grafts for the treatment of skeletal pathology is a common practice in orthopaedic, craniomaxillofacial, dental, and plastic surgery. Autogenous bone graft is the established archetype but has disadvantages including donor site morbidity, limited supply, and prolonging operative time. In order to avoid these and other issues, bone graft substitute materials are becoming increasingly prevalent among surgeons for reconstructing skeletal defects and arthrodesis applications. Bone graft substitutes are biomaterials, biologics, and guided tissue/bone regenerative devices that can be used alone or in combinations as supplements or alternatives to autogenous bone graft. There is a growing interest and trend to specialize graft substitutes for specific indications and although there is good rationale for this indication-specific approach, the development and utility of a more universal bone graft substitute may provide a better answer for patients and surgeons. The aim of the present research focuses on the design, synthesis, and initial evaluation of D-glyceraldehyde crosslinked gelatin-hydroxyapatite composites for potential use as a bone graft substitutes. After initial establishment of rational material design, gelatinhydroxyapatite scaffolds were fabricated with different gelatin:hydroxyapatite ratios and crosslinking concentrations. The synthesized scaffolds were subsequently evaluated on the basis of their swelling behavior, porosity, density, percent composition, mechanical properties, and morphology and further assessed with respect to cell-biomaterial interaction and biomineralization in vitro. Although none of the materials achieved mechanical properties suitable for structural graft applications, a reproducible material design and synthesis was achieved with properties recognized to facilitate bone formation. Select scaffold formulations as well as a subset of scaffolds loaded with recombinant human bone morphogenetic protein-2 were

  14. Influence of liquid phase on physical properties of the new triphasic bone cement

    OpenAIRE

    A. Ślósarczyk; N. Osypanka; J. Czechowska; Z. Paszkiewicz; A. Zima

    2012-01-01

    Purpose: The aim of this work was to develop a new bone cement based on hydroxyapatite (HAp), βTCP and calcium sulfate hemihydrate (CSH) and to determine the influence of a liquid phase, used for cement pastes preparation, on physical properties of the final implant material.Design/methodology/approach: The powder phase consisting of CSH (60 wt.%) and HAp+ βTCP (40 wt.%) was applied. Composite samples were prepared using distilled water, chitosan and methylcellulose solutions as the liquid ph...

  15. Effect of Nanoparticle Incorporation and Surface Coating on Mechanical Properties of Bone Scaffolds: A Brief Review

    Directory of Open Access Journals (Sweden)

    Jesus Corona-Gomez

    2016-07-01

    Full Text Available Mechanical properties of a scaffold play an important role in its in vivo performance in bone tissue engineering, due to the fact that implanted scaffolds are typically subjected to stress including compression, tension, torsion, and shearing. Unfortunately, not all the materials used to fabricate scaffolds are strong enough to mimic native bones. Extensive research has been conducted in order to increase scaffold strength and mechanical performance by incorporating nanoparticles and/or coatings. An incredible improvement has been achieved; and some outstanding examples are the usage of nanodiamond, hydroxyapatite, bioactive glass particles, SiO2, MgO, and silver nanoparticles. This review paper aims to present the results, to summarize significant findings, and to give perspective for future work, which could be beneficial to future bone tissue engineering.

  16. Bioeutectic: a new ceramic material for human bone replacement.

    Science.gov (United States)

    De Aza, P N; Guitián, F; De Aza, S

    1997-10-01

    In the present work, a new way of obtaining bioactive ceramic materials with eutectic morphology is presented. To this purpose the binary system wollastonite-tricalcium phosphate was selected, taking into account the different bioactivity behaviour of both phases. The material is formed by quasi-spherical colonies composed of alternating radial lamellae of wollastonite and tricalcium phosphate. In in vitro experiments the material presents a high reactivity, with the formation of two well-differentiated zones of hydroxyapatite, one formed by alteration of the eutectic material with solution of the wollastonite into the simulated body fluid and subsequent pseudomorphic transformation of the tricalcium phosphate into hydroxyapatite, and the other, in the last stages of the experiments, by deposition of hydroxyapatite onto the surface of the material. The hydroxyapatite morphology, formed at the beginning of the reaction, is similar to that of porous bone. The method used opens the opportunity to develop a new family of bioactive materials with different constituents, binary or ternary, for which the authors propose the general name of bioeutectics. PMID:9307217

  17. Determination of Small Animal Long Bone Properties Using Densitometry

    Science.gov (United States)

    Breit, Gregory A.; Goldberg, BethAnn K.; Whalen, Robert T.; Hargens, Alan R. (Technical Monitor)

    1996-01-01

    Assessment of bone structural property changes due to loading regimens or pharmacological treatment typically requires destructive mechanical testing and sectioning. Our group has accurately and non-destructively estimated three dimensional cross-sectional areal properties (principal moments of inertia, Imax and Imin, and principal angle, Theta) of human cadaver long bones from pixel-by-pixel analysis of three non-coplanar densitometry scans. Because the scanner beam width is on the order of typical small animal diapbyseal diameters, applying this technique to high-resolution scans of rat long bones necessitates additional processing to minimize errors induced by beam smearing, such as dependence on sample orientation and overestimation of Imax and Imin. We hypothesized that these errors are correctable by digital image processing of the raw scan data. In all cases, four scans, using only the low energy data (Hologic QDR-1000W, small animal mode), are averaged to increase image signal-to-noise ratio. Raw scans are additionally processed by interpolation, deconvolution by a filter derived from scanner beam characteristics, and masking using a variable threshold based on image dynamic range. To assess accuracy, we scanned an aluminum step phantom at 12 orientations over a range of 180 deg about the longitudinal axis, in 15 deg increments. The phantom dimensions (2.5, 3.1, 3.8 mm x 4.4 mm; Imin/Imax: 0.33-0.74) were comparable to the dimensions of a rat femur which was also scanned. Cross-sectional properties were determined at 0.25 mm increments along the length of the phantom and femur. The table shows average error (+/- SD) from theory of Imax, Imin, and Theta) over the 12 orientations, calculated from raw and fully processed phantom images, as well as standard deviations about the mean for the femur scans. Processing of phantom scans increased agreement with theory, indicating improved accuracy. Smaller standard deviations with processing indicate increased

  18. Age variations in the properties of human tibial trabecular bone and cartilage

    DEFF Research Database (Denmark)

    Ding, Ming

    2000-01-01

    Initiated and motivated by clinical and scientific problems such as age-related bone fracture, prosthetic loosening, bone remodeling, and degenerative bone diseases, much significant research on the properties of trabecular bone has been carried out over the last two decades. This work has mainly...... investigate the age-related and osteoarthrosis-related changes in the mechanical properties of the human tibial cartilage-bone complex; and 3) to evaluate mutual associations among various properties. Normal specimens from human autopsy proximal tibiae were used for investigation of age variations in the...... focused on the central vertebral trabecular bone, while little is known about age-related changes in the properties of human peripheral (tibial) trabecular bone. Knowledge of the properties of peripheral (tibial) trabecular bone is of major importance for the understanding of degenerative diseases such as...

  19. Influence of liquid phase on physical properties of the new triphasic bone cement

    Directory of Open Access Journals (Sweden)

    A. Ślósarczyk

    2012-04-01

    Full Text Available Purpose: The aim of this work was to develop a new bone cement based on hydroxyapatite (HAp, βTCP and calcium sulfate hemihydrate (CSH and to determine the influence of a liquid phase, used for cement pastes preparation, on physical properties of the final implant material.Design/methodology/approach: The powder phase consisting of CSH (60 wt.% and HAp+ βTCP (40 wt.% was applied. Composite samples were prepared using distilled water, chitosan and methylcellulose solutions as the liquid phases. Rheological properties of the solutions were measured by Brookfield rheometer. Initial and final setting times of the cement pastes were determined. Phase composition of hardened bodies was established using XRD method. Microstructure was investigated by SEM while pore size distribution by mercury porosimetry. Compressive strength was measured by Instron Universal Testing Machine.Findings: According to the conducted rheological measurements of the methylcellulose and chitosan solutions as well as evaluated cement pastes and hardened bodies properties, the optimal setting liquids were chosen.Research limitations/implications: The evaluation of a biological response to the developed materials, including in vitro and in vivo experiments, need to be done.Practical implications: The possibility of creation the physical properties of setting in vivo composites, designed for filling bone defects, via establishing the suitable liquid phase was confirmed.Originality/value: The new composite type triphasic bone substitute, based on CSH, HAp and βTCP, with superior resorbability in comparison to the commercially available calcium phosphate bone cements was developed. The influence of liquid phase on the microstructure and mechanical strength of this implant material was determined.

  20. The Development of Biomimetic Spherical Hydroxyapatite/Polyamide 66 Biocomposites as Bone Repair Materials

    Directory of Open Access Journals (Sweden)

    Xuesong Zhang

    2014-01-01

    Full Text Available A novel biomedical material composed of spherical hydroxyapatite (s-HA and polyamide 66 (PA biocomposite (s-HA/PA was prepared, and its composition, mechanical properties, and cytocompatibility were characterized and evaluated. The results showed that HA distributed uniformly in the s-HA/PA matrix. Strong molecule interactions and chemical bonds were presented between the s-HA and PA in the composites confirmed by IR and XRD. The composite had excellent compressive strength in the range between 95 and 132 MPa, close to that of natural bone. In vitro experiments showed the s-HA/PA composite could improve cell growth, proliferation, and differentiation. Therefore, the developed s-HA/PA composites in this study might be used for tissue engineering and bone repair.

  1. Study on β-TCP Coated Porous Mg as a Bone Tissue Engineering Scaffold Material

    Institute of Scientific and Technical Information of China (English)

    Fang Geng; Lili Tan; Bingchun Zhang; Chunfu Wu; Yonglian He; Jingyu Yang; Ke Yang

    2009-01-01

    Three-dimensional honeycomb-structured magnesium (Mg) scaffolds with interconnected pores of accurately controlled pore size and porosity were fabricated by laser perforation technique. Biodegradable and bioactive β-tricalcium phosphate (β-TCP) coatings were prepared on the porous Mg to further improve its biocompatibility, and the biodegradation mechanism was simply evaluated in vitro. It was found that the mechanical properties of this type of porous Mg significantly depended on its porosity. Elastic modulus and compressive strength similar to human bones could be obtained for the porous Mg with porosity of 42.6%-51%. It was observed that the human osteosarcoma cells (UMR106) were well adhered and proliferated on the surface of the β-TCP coated porous Mg, which indicates that the β-TCP coated porous Mg is promising to be a bone tissue engineering scaffold material.

  2. Nano hydroxyapatite-coated implants improve bone nanomechanical properties.

    Science.gov (United States)

    Jimbo, R; Coelho, P G; Bryington, M; Baldassarri, M; Tovar, N; Currie, F; Hayashi, M; Janal, M N; Andersson, M; Ono, D; Vandeweghe, S; Wennerberg, A

    2012-12-01

    Nanostructure modification of dental implants has long been sought as a means to improve osseointegration through enhanced biomimicry of host structures. Several methods have been proposed and demonstrated for creating nanotopographic features; here we describe a nanoscale hydroxyapatite (HA)-coated implant surface and hypothesize that it will hasten osseointegration and improve its quality relative to that of non-coated implants. Twenty threaded titanium alloy implants, half prepared with a stable HA nanoparticle surface and half grit-blasted, acid-etched, and heat-treated (HT), were inserted into rabbit femurs. Pre-operatively, the implants were morphologically and topographically characterized. After 3 weeks of healing, the samples were retrieved for histomorphometry. The nanomechanical properties of the surrounding bone were evaluated by nanoindentation. While both implants revealed similar bone-to-implant contact, the nanoindentation demonstrated that the tissue quality was significantly enhanced around the HA-coated implants, validating the postulated hypothesis. PMID:23045363

  3. Hyaluronic Acid Hydrogels with Controlled Degradation Properties for Oriented Bone Regeneration

    OpenAIRE

    J. Patterson; Siew, R; Herring, SW; Lin, ASP; Guldberg, R; Stayton, PS

    2010-01-01

    Non-healing fractures can result from trauma, disease, or age-related bone loss. While many treatments focus on restoring bone volume, few try to recapitulate bone organization. However, the native architecture of bone is optimized to provide its necessary mechanical properties. Hyaluronic acid (HA) hydrogel scaffold systems with tunable degradation properties were developed for the controlled delivery of osteoinductive and angiogenic growth factors, thus affecting the quantity and quality of...

  4. Experimental, theoretical and numerical investigation of the nonlinear micromechanical properties of bone

    OpenAIRE

    Schwiedrzik, Johann Jakob

    2014-01-01

    Aging societies suffer from an increasing incidence of bone fractures. Bone strength depends on the amount of mineral measured by clinical densitometry, but also on the micromechanical properties of the bone hierarchical organization. A good understanding has been reached for elastic properties on several length scales, but up to now there is a lack of reliable postyield data on the lower length scales. In order to be able to describe the behavior of bone at the microscale, an anisotropic...

  5. Evaluation of bone response to synthetic bone grafting material treated with argon-based atmospheric pressure plasma

    International Nuclear Information System (INIS)

    Bone graft materials are utilized to stimulate healing of bone defects or enhance osseointegration of implants. In order to augment these capabilities, various surface modification techniques, including atmospheric pressure plasma (APP) surface treatment, have been developed. This in vivo study sought to assess the effect of APP surface treatment on degradation and osseointegration of Synthograft™, a beta-tricalcium phosphate (β-TCP) synthetic bone graft. The experimental (APP-treated) grafts were subjected to APP treatment with argon for a period of 60 s. Physicochemical characterization was performed by environmental scanning electron microscopy, surface energy (SE), and x-ray photoelectron spectroscopy analyses both before and after APP treatment. Two APP-treated and two untreated grafts were surgically implanted into four critical-size calvarial defects in each of ten New Zealand white rabbits. The defect samples were explanted after four weeks, underwent histological analysis, and the percentages of bone, soft tissue, and remaining graft material were quantified by image thresholding. Material characterization showed no differences in particle surface morphology and that the APP-treated group presented significantly higher SE along with higher amounts of the base material chemical elements on it surface. Review of defect composition showed that APP treatment did not increase bone formation or reduce the amount of soft tissue filling the defect when compared to untreated material. Histologic cross-sections demonstrated osteoblastic cell lines, osteoid deposition, and neovascularization in both groups. Ultimately, argon-based APP treatment did not enhance the osseointegration or degradation of the β-TCP graft. Future investigations should evaluate the utility of gases other than argon to enhance osseointegration through APP treatment. - Highlights: • Degradation/osseointegration of bone graft treated with argon-based APP is studied. • APP treatment did

  6. Mechanical properties and osteogenic potential of hydroxyapatite-PLGA-collagen biomaterial for bone regeneration.

    Science.gov (United States)

    Bhuiyan, Didarul B; Middleton, John C; Tannenbaum, Rina; Wick, Timothy M

    2016-08-01

    A bone graft is a complicated structure that provides mechanical support and biological signals that regulate bone growth, reconstruction, and repair. A single-component material is inadequate to provide a suitable combination of structural support and biological stimuli to promote bone regeneration. Multicomponent composite biomaterials lack adequate bonding among the components to prevent phase separation after implantation. We have previously developed a novel multistep polymerization and fabrication process to construct a nano-hydroxyapatite-poly(D,L-lactide-co-glycolide)-collagen biomaterial (abbreviated nHAP-PLGA-collagen) with the components covalently bonded to each other. In the present study, the mechanical properties and osteogenic potential of nHAP-PLGA-collagen are characterized to assess the material's suitability to support bone regeneration. nHAP-PLGA-collagen films exhibit tensile strength very close to that of human cancellous bone. Human mesenchymal stem cells (hMSCs) are viable on 2D nHAP-PLGA-collagen films with a sevenfold increase in cell population after 7 days of culture. Over 5 weeks of culture, hMSCs deposit matrix and mineral consistent with osteogenic differentiation and bone formation. As a result of matrix deposition, nHAP-PLGA-collagen films cultured with hMSCs exhibit 48% higher tensile strength and fivefold higher moduli compared to nHAP-PLGA-collagen films without cells. More interestingly, secretion of matrix and minerals by differentiated hMSCs cultured on the nHAP-PLGA-collagen films for 5 weeks mitigates the loss of mechanical strength that accompanies PLGA hydrolysis. PMID:27120980

  7. Hierarcially biomimetic bone materials: from nanometer to millimeter

    Institute of Scientific and Technical Information of China (English)

    ZHANG W.; CUI F. Z.; LIAO S. S.

    2001-01-01

    @@ The bone composite was produced by biomimetic synthesis. It shows some features of natural bone in both composition and microstructure. And the collagen moleculars and the nano-crystal hydroxyapatite assemble into ultrastructure similar to natural bone. It possesses porous structure with porosity from 100μm to 500μm after mixed with PLA (poly lactic acid).

  8. Mechanical and biological properties of the micro-/nano-grain functionally graded hydroxyapatite bioceramics for bone tissue engineering.

    Science.gov (United States)

    Zhou, Changchun; Deng, Congying; Chen, Xuening; Zhao, Xiufen; Chen, Ying; Fan, Yujiang; Zhang, Xingdong

    2015-08-01

    Functionally graded materials (FGM) open the promising approach for bone tissue repair. In this study, a novel functionally graded hydroxyapatite (HA) bioceramic with micrograin and nanograin structure was fabricated. Its mechanical properties were tailored by composition of micrograin and nanograin. The dynamic mechanical analysis (DMA) indicated that the graded HA ceramics had similar mechanical property compared to natural bones. Their cytocompatibility was evaluated via fluorescent microscopy and MTT colorimetric assay. The viability and proliferation of rabbit bone marrow mesenchymal stem cells (BMSCs) on ceramics indicated that this functionally graded HA ceramic had better cytocompatibility than conventional HA ceramic. This study demonstrated that functionally graded HA ceramics create suitable structures to satisfy both the mechanical and biological requirements of bone tissues. PMID:25910818

  9. Influence of Nano-HA Coated Bone Collagen to Acrylic (Polymethylmethacrylate Bone Cement on Mechanical Properties and Bioactivity.

    Directory of Open Access Journals (Sweden)

    Tao Li

    Full Text Available This research investigated the mechanical properties and bioactivity of polymethylmethacrylate (PMMA bone cement after addition of the nano-hydroxyapatite(HA coated bone collagen (mineralized collagen, MC.The MC in different proportions were added to the PMMA bone cement to detect the compressive strength, compression modulus, coagulation properties and biosafety. The MC-PMMA was embedded into rabbits and co-cultured with MG 63 cells to exam bone tissue compatibility and gene expression of osteogenesis.15.0%(wt impregnated MC-PMMA significantly lowered compressive modulus while little affected compressive strength and solidification. MC-PMMA bone cement was biologically safe and indicated excellent bone tissue compatibility. The bone-cement interface crosslinking was significantly higher in MC-PMMA than control after 6 months implantation in the femur of rabbits. The genes of osteogenesis exhibited significantly higher expression level in MC-PMMA.MC-PMMA presented perfect mechanical properties, good biosafety and excellent biocompatibility with bone tissues, which has profoundly clinical values.

  10. Mycobacterium tuberculosis Contaminant Risk on Bone Marrow Aspiration Material from Iliac Bone Patients with Active Tuberculous Spondylitis

    Directory of Open Access Journals (Sweden)

    Ahmad Jabir Rahyussalim

    2016-01-01

    Full Text Available There was a concern on Mycobacterium tuberculosis spreading to the bone marrow, when it was applied on tuberculous spine infection. This research aimed to study the probability of using autologous bone marrow as a source of mesenchymal stem cell for patients with tuberculous spondylitis. As many as nine patients with tuberculous spondylitis were used as samples. During the procedure, the vertebral lesion material and iliac bone marrow aspirates were obtained for acid fast staining, bacteria culture, and PCR (polymerase chain reaction tests for Mycobacterium tuberculosis at the Clinical Microbiology Laboratory of Faculty of Medicine Universitas Indonesia. This research showed that there was a relationship between diagnostic confirmation of tuberculous spondylitis based on the PCR test and bacterial culture on the solid vertebral lesion material with the PCR test and bacterial culture from the bone marrow aspirates. If the diagnostic confirmation concluded positive results, then there was a higher probability that there would be a positive result for the bone marrow aspirates, so that it was not recommended to use autologous bone marrow as a source of mesenchymal stem cell for patients with tuberculous spondylitis unless the PCR and culture examination of the bone marrow showed a negative result.

  11. Mycobacterium tuberculosis Contaminant Risk on Bone Marrow Aspiration Material from Iliac Bone Patients with Active Tuberculous Spondylitis.

    Science.gov (United States)

    Rahyussalim, Ahmad Jabir; Kurniawati, Tri; Rukmana, Andriansjah

    2016-01-01

    There was a concern on Mycobacterium tuberculosis spreading to the bone marrow, when it was applied on tuberculous spine infection. This research aimed to study the probability of using autologous bone marrow as a source of mesenchymal stem cell for patients with tuberculous spondylitis. As many as nine patients with tuberculous spondylitis were used as samples. During the procedure, the vertebral lesion material and iliac bone marrow aspirates were obtained for acid fast staining, bacteria culture, and PCR (polymerase chain reaction) tests for Mycobacterium tuberculosis at the Clinical Microbiology Laboratory of Faculty of Medicine Universitas Indonesia. This research showed that there was a relationship between diagnostic confirmation of tuberculous spondylitis based on the PCR test and bacterial culture on the solid vertebral lesion material with the PCR test and bacterial culture from the bone marrow aspirates. If the diagnostic confirmation concluded positive results, then there was a higher probability that there would be a positive result for the bone marrow aspirates, so that it was not recommended to use autologous bone marrow as a source of mesenchymal stem cell for patients with tuberculous spondylitis unless the PCR and culture examination of the bone marrow showed a negative result. PMID:27294117

  12. Correction: Mechanical properties of femoral trabecular bone in dogs

    Directory of Open Access Journals (Sweden)

    Behrens Bernd-Arno

    2005-12-01

    Full Text Available Abstract After the publication of this work 1, we became aware of the fact that the frequency of the ultrasound transmitter that we used for determining the elastic moduli of the trabecular bone specimens was not correctly specified. The oscillation frequency of the ultrasound transmitter was 2 MHz (and not 100 MHz as stated in our work while we used a sampling rate of 100 MHz. In our publication, the oscillation frequency and sampling rate were confounded. Therefore also the statement in the discussion that we might have determined elastic moduli of trabecular bone tissue rather than the elastic properties of whole specimens because we used an ultrasound frequency > 2 MHz is wrong and has to be omitted. For measurement, the cubic bone specimens were not immersed in Ringer's solution but only were kept moist all the time. Apart from these corrections concerning the methods and interpretation of the data, the results reported in our publication and the conclusions are absolutely correct. We apologize for the inconvenience that this inaccuracy may have caused.

  13. Scattering Properties of Candidate Planetary Regolith Materials

    Science.gov (United States)

    Nelson, R. M.; Smythe, W. D.; Hapke, B. W.; Hale, A. S.; Piatek, J. A.

    2001-01-01

    The laboratory investigation of the scattering properties of candidate planetary regolith materials is an important technique for understanding the physical properties of a planetary regolith. Additional information is contained in the original extended abstract.

  14. Fundamentals of semiconductors physics and materials properties

    CERN Document Server

    Yu, Peter Y

    2005-01-01

    Provides detailed explanations of the electronic, vibrational, transport, and optical properties of semiconductors. This textbook emphasizes understanding the physical properties of Si and similar tetrahedrally coordinated semiconductors and features an extensive collection of tables of material parameters, figures, and problems.

  15. Design of materials with prescribed nonlinear properties

    DEFF Research Database (Denmark)

    Wang, Fengwen; Sigmund, Ole; Jensen, Jakob Søndergaard

    2014-01-01

    We systematically design materials using topology optimization to achieve prescribed nonlinear properties under finite deformation. Instead of a formal homogenization procedure, a numerical experiment is proposed to evaluate the material performance in longitudinal and transverse tensile tests...

  16. Relationship between nanoscale mineral properties and calcein labeling in mineralizing bone surfaces.

    Science.gov (United States)

    Aido, Marta; Kerschnitzki, Michael; Hoerth, Rebecca; Burghammer, Manfred; Montero, Cédric; Checa, Sara; Fratzl, Peter; Duda, Georg N; Willie, Bettina M; Wagermaier, Wolfgang

    2014-08-01

    Bone's mineral properties, such as particle thickness and degree of alignment have been associated with bone quality. Bone formation, remodeling, aging of the tissue and mineral homeostasis influence mineral particle properties leading to specific patterns across bone. Scanning small angle X-ray scattering (sSAXS) with synchrotron radiation is a powerful tool, which allows us to study bone's nanoscale mineral properties in a position-resolved way. We used sSAXS, fluorescence light microscopy and backscattered electron (BSE) imaging to study bone's mineral properties at the tibial midshaft of in vivo-loaded mice. By combining these techniques, we could detect local changes in mineral properties. Regions labeled with calcein fluorochrome have lower mean mineral thickness and degree of mineral alignment. We also observed thinner and less aligned mineral particles near blood vessels. We conclude that mineral properties (i) are altered by fluorochrome labeling and (ii) depend on the proximity to blood vessels. PMID:25158172

  17. The Preparation and In Vitro Evaluations of a Nanoscaled Injectable Bone Repair Material

    OpenAIRE

    2015-01-01

    There are usually two forms of bone repair materials, block and granular, for common clinical use. This paper describes a novel injectable material, nano-HA/collagen/alginate (nHAC/Alg) composite biomaterial, including its preparation and evaluations in vitro. Based on the idea of bionics and the study of collagen/calcium phosphate salt composite materials, the injectable bone repair material was developed. Then, human bone marrow stem cells (hBMSCs) were cultured on the nHAC/Alg material. Th...

  18. A perfusion bioreactor system efficiently generates cell‐loaded bone substitute materials for addressing critical size bone defects

    Science.gov (United States)

    Kleinhans, Claudia; Mohan, Ramkumar Ramani; Vacun, Gabriele; Schwarz, Thomas; Haller, Barbara; Sun, Yang; Kahlig, Alexander; Kluger, Petra; Finne‐Wistrand, Anna; Walles, Heike

    2015-01-01

    Abstract Critical size bone defects and non‐union fractions are still challenging to treat. Cell‐loaded bone substitutes have shown improved bone ingrowth and bone formation. However, a lack of methods for homogenously colonizing scaffolds limits the maximum volume of bone grafts. Additionally, therapy robustness is impaired by heterogeneous cell populations after graft generation. Our aim was to establish a technology for generating grafts with a size of 10.5 mm in diameter and 25 mm of height, and thus for grafts suited for treatment of critical size bone defects. Therefore, a novel tailor‐made bioreactor system was developed, allowing standardized flow conditions in a porous poly(L‐lactide‐co‐caprolactone) material. Scaffolds were seeded with primary human mesenchymal stem cells derived from four different donors. In contrast to static experimental conditions, homogenous cell distributions were accomplished under dynamic culture. Additionally, culture in the bioreactor system allowed the induction of osteogenic lineage commitment after one week of culture without addition of soluble factors. This was demonstrated by quantitative analysis of calcification and gene expression markers related to osteogenic lineage. In conclusion, the novel bioreactor technology allows efficient and standardized conditions for generating bone substitutes that are suitable for the treatment of critical size defects in humans. PMID:26011163

  19. Remodeling of the bone material containing microcracks: A theoretical analysis

    Science.gov (United States)

    Ramtani, S.; Zidi, M.

    1999-12-01

    The question is, what happens when the bone loses its ability for load-driven adaptation, when damage is no longer repaired as it seems to be the case for bone loss associated with age, medication or disease? In this study, we tempt to show how damage can influence the remodeling process. A thermodynamic theoretical framework is therefore provided as a basis for a consistent formulation of bone remodeling involving a chemical reaction and mass transfer between two constituents in presence of microcracks.

  20. Bone-repair properties of biodegradable hydroxyapatite nano-rod superstructures

    Science.gov (United States)

    D'Elía, Noelia L.; Mathieu, Colleen; Hoemann, Caroline D.; Laiuppa, Juan A.; Santillán, Graciela E.; Messina, Paula V.

    2015-11-01

    Nano-hydroxyapatite (nano-HAp) materials show an analogous chemical composition to the biogenic mineral components of calcified tissues and depending on their topography they may mimic the specific arrangement of the crystals in bone. In this work, we have evaluated the potential of four synthesized nano-HAp superstructures for the in vitro conditions of bone-repair. Experiments are underway to investigate the effects of the material microstructure, surface roughness and hydrophilicity on their osseo-integration, osteo-conduction and osteo-induction abilities. Materials were tested in the presence of both, rat primary osteoblasts and rabbit mesenchymal stem cells. The following aspects are discussed: (i) cytotoxicity and material degradation; (ii) rat osteoblast spreading, proliferation and differentiation; and (iii) rabbit mesenchymal stem cell adhesion on nano-HAp and nano-HAp/collagen type I coatings. We effectively prepared a material based on biomimetic HAp nano-rods displaying the appropriate surface topography, hydrophilicity and degradation properties to induce the in vitro desired cellular responses for bone bonding and healing. Cells seeded on the selected material readily attached, proliferated and differentiated, as confirmed by cell viability, mitochondrial metabolic activity, alkaline phosphatase (ALP) activity and cytoskeletal integrity analysis by immunofluorescence localization of alpha-smooth muscle actin (α-SMA) protein. These results highlight the influence of material's surface characteristics to determine their tissue regeneration potential and their future use in engineering osteogenic scaffolds for orthopedic implants.Nano-hydroxyapatite (nano-HAp) materials show an analogous chemical composition to the biogenic mineral components of calcified tissues and depending on their topography they may mimic the specific arrangement of the crystals in bone. In this work, we have evaluated the potential of four synthesized nano-HAp superstructures

  1. Exploring gamma radiation effect on exoelectron emission properties of bone

    Energy Technology Data Exchange (ETDEWEB)

    Zakaria, M.; Dekhtyar, Y.; Bogucharska, T.; Noskov, V. [Riga Technical Univ., Biomedical Engineering and Nanotechnology Institute (Latvia)

    2006-07-01

    Gamma radiation is used for radiation therapy to treat carcinogenic diseases including bone cancer. Ionising radiation kills carcinogenic calls. However, there are side effects of the gamma radiation on the bone surface electron structure. One of the effects is in the form of altering electron density of states of bone that, with time, influences biomedical reactions on bone life condition. (authors)

  2. Immunological study on the transplantation of an improved deproteinized heterogeneous bone scaffold material in tissue engineering

    Institute of Scientific and Technical Information of China (English)

    LIU Lei; PEI Fu-xing; TU Chong-qi; ZHOU Zong-ke; LI Qi-hong

    2008-01-01

    Objective: To observe the immune response after the transplantation of a deproteinized heterogeneous bone scaffold and provides the theoretic reference for clinical practice. Methods: The fresh pig bone and deproteinized bone were transplanted respectively to establish BABL/C thigh muscle pouches model of male mice and take the samples for detection at 1, 2, 4, 6 weeks after operation. Lymphocyte stimulation index, subset analysis, serum specific antibody IgG, cytokine detection and topographic histologic reaction after implantation were investigated. Results: After the transplantation of deproteinized bone, lymphocyte stimulation index, CD4+ and CD8+ T-lymphocyte subsets, serum specific antibody IgG and cytokines in deproteinized bone group were significantly lower than those in fresh pig bone group at each time point (P<0.05). The histological examination found that in fresh bone group at each time point, a large quantity of inflammatory cells infiltrated in the surrounding of bone graft, and they were mainly lymphocytes, including macrophages and monocytes. In deproteinized bone group, there were few inflammatory cells infiltration around bone graft one weekafter operation.The lymphocytes were decreased as time went by.At 6 weeks,fibroblasts and fibrous tissue grew into the graft,and osteoclasts and osteoprogenitor cells appeared on the verge.Conelusions:The established heterogeneous deproteinized bone has low immunogenicity and is a poten-fially ideal scaffold material for bone tissue engineering.

  3. Mechanical properties of human bone-tendon-bone grafts preserved by different methods and radiation sterilised

    International Nuclear Information System (INIS)

    Full text: Patellar tendon auto and allografts are commonly used in orthopaedic surgery for reconstruction of the anterior crucial ligaments (ACL). Autografts are mainly used for primary reconstruction, while allografts are useful for revision surgery. To avoid the risk of infection diseases transmission allografts should be radiation-sterilised. As radiation-sterilisation is supposed to decrease the mechanical strength of tendon tissue, it is important to establish methods of allografts preservation and sterilisation resulting in their best quality and safety. Therefore, the purpose of the study was to compare the tensile strength of the central one third of human patellar tendon (as used for ACL reconstruction), preserved by different methods (deep fresh freezing, lyophilisation) and subsequently radiation-sterilised with doses of 0 (control), 25, 50 or 100 kGy. Bone-tendon-bone grafts were prepared from cadaveric human patella tendon with both patellar and tibial attachments. BTB grafts were preserved by deep freezing, glicerolisation or lyophilisation and radiation-sterilised with doses of 0 (control), 25, 50 or 100 kGy. To estimate mechanical properties all samples were subjected to tensile tests to failure using Instron system. Before these tests all lyophilised grafts were rehydrated. We found decrease of tensile strength of irradiated grafts compared to non-irradiated controls. Obtained results of the mechanical testing of studied grafts indicate their potential usefulness for clinical applications.(Author)

  4. Histological evaluation of bone response to bioactive ceramics as graft material in rats

    Directory of Open Access Journals (Sweden)

    Kršljak Elena

    2005-01-01

    Full Text Available This experimental study was carried out on 35 Albino Wister rats Artificially created bone defects were grafted with bioactive ceramic materials or control material. Histological analysis was preformed 8 weeks and 6 months after the implantation. The results revealed that bone regeneration occurred in defects treated with bioactive ceramic materials while in the defects treated with the control material signs of tissue rejection were present. As stated before, it could be concluded that bioactive ceramics can be recommended as bone substitutes in orthopedic surgery and dentistry.

  5. Bone graft materials in fixation of orthopaedic implants in sheep

    DEFF Research Database (Denmark)

    Babiker, Hassan

    2013-01-01

    bone and includes bone collagen, morphogenetic proteins and growth factors. The combination of DBM with CB and with allograft might improve the healing potential of these grafts around non-cemented orthopaedic implants and thereby the implant fixation. Study I investigates the effect of HA...

  6. Osteoconductivity and mechanical properties of a new bioactive bone cement

    Energy Technology Data Exchange (ETDEWEB)

    Shinzato, S.; Nakamura, T. [Kyoto Univ. (Japan). Dept. of Orthopaedic Surgery; Kokubo, T. [Kyoto Univ. (Japan). Dept. of Material Chemistry; Kitamura, Y. (Nippon Electric Glass Co. Ltd., Otsu)

    2001-07-01

    Osteoconductivity and mechanical properties of a new bioactive bone cement (designated GBC) consisting of high molecular weight polymethyl methacrylate (PMMA) as an organic matrix and bioactive glass beads as an inorganic filler have been evaluated. The bioactive beads consisting of MgO-CaO-SiO{sub 2}-P{sub 2}O{sub 5}CaF{sub 2} glass, have been newly designed and a novel PMMA powder was selected. The aim of the present study is to compare GBC's osteoconductivity and mechanical properties with cements consisting of the same matrix as GBC and either apatite- and wollastonite-containing glass-ceramic (AW-GC) powder (designated AWC) or sintered hydroxyapatite (HA) powder (designated HAC) and to examine effects of the amount of the bioactive glass beads filler added to GBC, and to decide the most suitable amount of the filler content. The bioactive glass beads added to the cements amounted 30, 40, 50, 60, and 70 wt%, and AW-GC powder and HA powder added to the cements amounted 70 wt%. Each cement was designated respectively GBC30, 40, 50, 60, 70, AWC70, and HAC70. The bending strength of GBC70 was significantly higher than that of AWC70 and HAC70. The compressive strength and the elastic modulus of bending of GBC increased as the glass beads content increased. The handling property of each GBC was comparable with that of conventional PMMA bone cement. Cements were packed into intramedullar canals of rat tibiae in order to evaluate osteoconductivity determined by an affinity index.

  7. Spin-crossover materials properties and applications

    CERN Document Server

    Halcrow, Malcolm A

    2013-01-01

    The phenomenon of spin-crossover has a large impact on the physical properties of a solid material, including its colour, magnetic moment, and electrical resistance. Some materials also show a structural phase change during the transition. Several practical applications of spin-crossover materials have been demonstrated including display and memory devices, electrical and electroluminescent devices, and MRI contrast agents. Switchable liquid crystals, nanoparticles, and thin films of spin-crossover materials have also been achieved. Spin-Crossover Materials: Properties and Applicat

  8. Microindentation for In Vivo Measurement of Bone Tissue Mechanical Properties in Humans

    OpenAIRE

    Diez-Perez, Adolfo; Güerri, Roberto; Nogues, Xavier; Cáceres, Enric; Peña, Maria Jesus; Mellibovsky, Leonardo; Randall, Connor; Bridges, Daniel; Weaver, James C.; Proctor, Alexander; Brimer, Davis; Koester, Kurt J.; Ritchie, Robert O.; Hansma, Paul K.

    2010-01-01

    Bone tissue mechanical properties are deemed a key component of bone strength, but their assessment requires invasive procedures. Here we validate a new instrument, a reference point indentation (RPI) instrument, for measuring these tissue properties in vivo. The RPI instrument performs bone microindentation testing (BMT) by inserting a probe assembly through the skin covering the tibia and, after displacing periosteum, applying 20 indentation cycles at 2 Hz each with a maximum force of 11 N....

  9. Mechanical properties of the normal human cartilage-bone complex in relation to age

    DEFF Research Database (Denmark)

    Ding, Ming; Dalstra, M; Linde, F; Hvid, I

    OBJECTIVE: This study investigates the age-related variations in the mechanical properties of the normal human tibial cartilage-bone complex and the relationships between cartilage and bone. DESIGN: A novel technique was applied to assess the mechanical properties of the cartilage and bone by mea...... tissues that are of importance for the understanding of the etiology and pathogenesis of degenerative joint diseases, such as arthrosis....

  10. Structural mechanical properties of radiation-sterilized human Bone-Tendon-Bone grafts preserved by different methods.

    Science.gov (United States)

    Gut, Grzegorz; Marowska, Joanna; Jastrzebska, Anna; Olender, Ewa; Kamiński, Artur

    2016-06-01

    To avoid the risk of infectious disease transmission from donor to recipient, allografts should be terminally sterilized. In the previous paper (Kaminski et al. in Cell Tissue Bank 10:215-219, 2009) we presented the effect of various methods of preservation (deep fresh freezing, glycerolization, lyophilization), followed by irradiation with different doses of electron beam (EB), on material (intrinsic) mechanical properties of human patellar tendons cut out as for anterior cruciate ligament reconstruction, obtained in failure tensile test. As structural mechanical properties are equally important to predict the behaviour of the graft as a whole functional unit, the purpose of the present paper was to show the results for failure load and elongation, obtained in the same experiment. Paired Bone-Tendon-Bone grafts (BTB) were prepared from cadaveric human patella tendons with both patellar and tibial attachments. They were preserved by deep freezing, glycerolization or lyophilization and subsequently EB-irradiated with the doses of 25, 35, 50 or 100 kGy (fresh-frozen grafts) or a single dose of 35 kGy (glycerolized and lyophilized grafts). Each experimental (irradiated) group was provided with control (non-irradiated), donor-matched group. The specimens from all groups were subjected to mechanical failure tensile test with the use of Instron system in order to measure their structural properties (failure load and elongation). All lyophilized grafts were rehydrated before mechanical testing. In our study we did not observe significant deterioration of structural mechanical properties of BTB grafts processed by fresh-freezing and then terminal sterilized with growing doses of EB up to 100 kGy. In contrast, BTB grafts processed by glycerolization or lyophilization and irradiated with 35 kGy showed significant decrease of failure load. Obtained results suggest that deep-frozen irradiated grafts retain their initial mechanical properties to an extent which does not

  11. Dynamic properties of ceramic materials

    International Nuclear Information System (INIS)

    The present study offers new data and analysis on the transient shock strength and equation-of-state properties of ceramics. Various dynamic data on nine high strength ceramics are provided with wave profile measurements, through velocity interferometry techniques, the principal observable. Compressive failure in the shock wave front, with emphasis on brittle versus ductile mechanisms of deformation, is examined in some detail. Extensive spall strength data are provided and related to the theoretical spall strength, and to energy-based theories of the spall process. Failure waves, as a mechanism of deformation in the transient shock process, are examined. Strength and equation-of-state analysis of shock data on silicon carbide, boron carbide, tungsten carbide, silicon dioxide and aluminum nitride is presented with particular emphasis on phase transition properties for the latter two. Wave profile measurements on selected ceramics are investigated for evidence of rate sensitive elastic precursor decay in the shock front failure process

  12. A new biphasic osteoinductive calcium composite material with a negative Zeta potential for bone augmentation

    Directory of Open Access Journals (Sweden)

    Maciejewski Oliver

    2009-06-01

    Full Text Available Abstract The aim of the present study was to analyze the osteogenic potential of a biphasic calcium composite material (BCC with a negative surface charge for maxillary sinus floor augmentation. In a 61 year old patient, the BCC material was used in a bilateral sinus floor augmentation procedure. Six months postoperative, a bone sample was taken from the augmented regions before two titanium implants were inserted at each side. We analyzed bone neoformation by histology, bone density by computed tomography, and measured the activity of voltage-activated calcium currents of osteoblasts and surface charge effects. Control orthopantomograms were carried out five months after implant insertion. The BCC was biocompatible and replaced by new mineralized bone after being resorbed completely. The material demonstrated a negative surface charge (negative Zeta potential which was found to be favorable for bone regeneration and osseointegration of dental implants.

  13. Determination of bone property by sound transfer function

    Institute of Scientific and Technical Information of China (English)

    QIAN Shengyou

    2001-01-01

    Sound transfer functions of bones were measured in vivo and in vitro with two accelerometers. Experimental results show that bones behave as a sound low-pass filter, and vibrate in several modes. Characteristics of sound traasfer function vary with individuals, but data obtained in both legs of one person are comparable. The resonant frequency of the sound transfer function indicates the size of defect in bone well, so it can be used for diagnosis of bone disease and assessment of fracture healing.

  14. Mechanical properties of femoral cortical bone following cemented hip replacement.

    Science.gov (United States)

    Ni, G X; Lu, W W; Chiu, P K Y; Wang, Y; Li, Z Y; Zhang, Y G; Xu, B; Deng, L F; Luk, K D K

    2007-11-01

    Femoral bone remodeling following total hip replacement is a big concern and has never been examined mechanically. In this study, six goats underwent unilateral cemented hip hemiarthroplasty with polymethyl methacrylate (PMMA) bone cement. Nine months later animals were sacrificed, and the femoral cortical bone slices at different levels were analysed using microhardness testing and microcomputed tomography (micro-CT) scanning. Implanted femurs were compared to contralateral nonimplanted femurs. Extensive bone remodeling was demonstrated at both the proximal and middle levels, but not at the distal level. Compared with the nonimplanted side, significant decreases were found in the implanted femur in cortical bone area, bone mineral density, and cortical bone hardness at the proximal level, as well as in bone mineral density and bone hardness at the middle level. However, no significant difference was observed in either variable for the distal level. In addition, similar proximal-to-distal gradient changes were revealed both in cortical bone microhardness and bone mineral density. From the mechanical point of view, the results of the present study suggested that stress shielding is an important mechanical factor associated with bone adaptation following total hip replacement. PMID:17506504

  15. X-ray spectrometric determination of thorium in bone and other biological materials

    International Nuclear Information System (INIS)

    An x-ray spectrometric method has been developed for the determination of thorium in bone and other biological materials. The limit of detection at the 95% confidence level is 20 ng. This corresponds to a concentration of 2 ppb in a 10-g sample of bone ash

  16. The influence of sterilization on the osteoinductive properties of bone in rat bone marrow cell culture

    International Nuclear Information System (INIS)

    Bone allografting is useful in the reconstruction of defects or supplementation of bone required during the treatment of bone tumors or comminuted fractures. Gamma-irradiation or heat-treatment at 60degC for 10 h or 80degC for 10 min are recognized procedures for the sterilization of bone before grafting. We investigated the ability of sterilized bone to induce proliferation in rat bone marrow cell cultures, and to induce alkaline phosphatase (ALP) activity in the cells. Addition of irradiated bone resulted in increased numbers of bone marrow cells and ALP activity in such cultures. However, larger doses of radiation to the bones suppressed this cell proliferation-inducing activity, whereas induction of ALP activity was not depressed by higher radiation doses. When the inducing activity was compared after the various sterilization processes, processed bones increased the cell number in culture by 45 percent and 35 percent compared with controls on days 7 and 14, respectively, despite sterilization. ALP activity was also increased by the processed bones (37 percent and 9 percent compared with controls on days 7 and 14, respectively), and this was again independent of the sterilization method employed. These results indicate that osteoinductive activity is retained after sterilization by either of the common methods employed. (author)

  17. Bone cell-material interactions on metal-ion doped polarized hydroxyapatite

    International Nuclear Information System (INIS)

    The objective of this work is to study the influence of Mg2+ and Sr2+ dopants on in vitro bone cell-material interactions of electrically polarized hydroxyapatite [HAp, Ca10(PO4)6(OH)2] ceramics with an aim to achieve additional advantage of matching bone chemistry along with the original benefits of electrical polarization treatment relevant to biomedical applications. To achieve our research objective, commercial phase pure HAp has been doped with MgO, and SrO in single, and binary compositions. All samples have been sintered at 1200 deg. C for 2 h and subsequently polarized using an external d.c. field (2.0 kV/cm) at 400 deg. C for 1 h. Combined addition of 1 wt.% MgO/1 wt.% SrO in HAp has been most beneficial in enhancing the polarizability in which stored charge was 4.19 μC/cm2 compared to pure HAp of 2.23 μC/cm2. Bone cell-material interaction has been studied by culturing with human fetal osteoblast cells (hFOB) for a maximum of 7 days. Scanning electron microscope (SEM) images of cell morphology reveal that favorable surface properties and dopant chemistry lead to good cellular adherence and spreading on negatively charged surfaces of both Sr2+ and Mg2+ doped HAp samples over undoped HAp. MTT assay results at 7 days show the highest viable cell densities on the negatively charged surfaces of binary doped HAp samples, while positive charged doped HAp surfaces exhibit limited cellular growth in comparison to neutral surfaces.

  18. Sterilisation of allograft cortical bone using gamma irradiation: effect on strength and material ultrastructure

    International Nuclear Information System (INIS)

    Full text: The use of allograft bone in revision joint and limb salvage surgery is widespread and increasing (Buck B.E. et al, Clin Orthop 303: 8-17, 1994). To reduce the risk of disease transmission from donor graft contamination (particularly HIV and hepatitis) sterilisation is practiced worldwide. Gamma (γ)-irradiation using a dose of 1.5 - 2.5 Mrads is common. However, γ-irradiation is known to reduce bone strength, though the extent and mechanisms are controversial (eg Bright RW et al, Trans Orthop Res Soc 3: 210, 1978). We measured the effect of γ-irradiation on bone strength and properties reflecting bone material ultrastructure. Diaphyseal bone was obtained from the femur of a 47 year-old male would-be donor with suspicious hepatitis serology. Beams of cortical bone (long axes parallel to the femur) were cut using a low speed diamond saw bathed in Ringer's solution. Four groups were irradiated with γ-rays (0, 1.5, 2.5 and 5.0±0.5[SD] Mrads). Blinded investigations were performed: Ultimate stress (Ult Stress, N= 16 replicates in each dose group). Each beam was loaded at its midpoint at a rate of 25 mm/min until failure, while its ends were supported 40 mms apart. Ult stress was calculated from 3-point bending theory using the load vs displacement curve and the cross-sectional area of the break (Power RA et al, submitted to J Bone and Joint Surg). Differential scanning calorimetry (DSC) was performed over the range -15 to +5 deg C. Samples were demineralized and small (7-10 mg) blocks were cut and sealed in stainless steel calorimetry capsules. The enthalpy (reflecting the normalised free water content) was calculated from the sample mass plus area under the heat capacity curve. Pyridinoline collagen (acid-insoluble) crosslinks (Pyrid, N=10) (Randall D et al, JBone and Min Res, 1996, in press) were determined from 5-mm3 demineralised, freeze dried samples. Small and medium angle X-ray diffraction (XRD, N=5). Demineralised bone was sliced into thin strips

  19. Study of osteoporosis through the measurement of bone density, trace elements, biomechanical properties and immunocytochemicals

    International Nuclear Information System (INIS)

    Osteoporosis is defined as an absolute decrease in the amount of bone to a level below required for mechanical support. It is an important bone disease in elderly people in many countries. Unfortunately, there is no reliable statistical data in Turkey for the incidence of osteoporosis. A decrease in bone mass is the important cause in fractures in osteoporosis. Therefore, we intend to study both bone density and other variables such as trace elements, biomechanical properties and other immunocytochemicals in bone, all combined might give an information about the cause and prevention of osteoporosis. (author)

  20. Magnetic materials fundamentals, products, properties, applications

    CERN Document Server

    Hilzinger, Rainer

    2013-01-01

    At a practical level, this compendium reviews the basics of soft and hard magnetic materials, discusses the advantages of the different processing routes for the exploitation of the magnetic properties and hence assists in proper, fail-safe and economic application of magnetic materials. Essential guidelines and formulas for the calculation of the magnetic and electrical properties, temperature and long-term stability of permanent magnets, of inductive components and magnetic shielding are compiled. Selected fields of application and case studies illustrate the large diversity of technical applications. Application engineers will appreciate the comprehensive compilation of the properties and detailed characteristic curves of modern soft and hard magnetic materials. Materials scientists will enjoy the presentation of the different processing routes and their impact on the magnetic properties and students will profit from the survey from the basics of magnetism down to the applications in inductive components, ...

  1. Materials Properties Research at MSFC

    Science.gov (United States)

    Presson, Joan B.; Burdine, Robert (Technical Monitor)

    2002-01-01

    MSFC is currently planning, organizing and directing test coupon fabrication and subsequent CTE testing for two mirror materials of specific interest to the AMSD and NGST programs, Beryllium 0-30H (Be 0-30H) and Ultra Low Expansion glass (ULE). The ULE test coupons are being fabricated at MSFC from AMSD core residuals provided by Kodak, The Be 0-30H test coupons are being fabricated at Brush Wellman using residuals from the SBMD. Both sets of test coupons will be sent to a test vendor selected through the NASA competitive proposal process with the test results being provided by written report to MSFC by the end of the fiscal year. The test results will become model input data for the AMSD analysts, both MSFC and contractor, providing an enhancement to the historical CTE data currently available.

  2. Spacecraft Charging Sensitivity to Material Properties

    Science.gov (United States)

    Minow, Joseph I.; Edwards, David L.

    2015-01-01

    Evaluating spacecraft charging behavior of a vehicle in the space environment requires knowledge of the material properties relevant to the charging process. Implementing surface and internal charging models requires a user to specify a number of material electrical properties including electrical resistivity parameters (dark and radiation induced), dielectric constant, secondary electron yields, photoemission yields, and breakdown strength in order to correctly evaluate the electric discharge threat posed by the increasing electric fields generated by the accumulating charge density. In addition, bulk material mass density and/or chemical composition must be known in order to analyze radiation shielding properties when evaluating internal charging. We will first describe the physics of spacecraft charging and show how uncertainties in material properties propagate through spacecraft charging algorithms to impact the results obtained from charging models. We then provide examples using spacecraft charging codes to demonstrate their sensitivity to material properties. The goal of this presentation is to emphasize the importance in having good information on relevant material properties in order to best characterize on orbit charging threats.

  3. Numerical investigation of the mechanical properties of the additive manufactured bone scaffolds fabricated by FDM: The effect of layer penetration and post-heating.

    Science.gov (United States)

    Naghieh, S; Karamooz Ravari, M R; Badrossamay, M; Foroozmehr, E; Kadkhodaei, M

    2016-06-01

    In recent years, thanks to additive manufacturing technology, researchers have gone towards the optimization of bone scaffolds for the bone reconstruction. Bone scaffolds should have appropriate biological as well as mechanical properties in order to play a decisive role in bone healing. Since the fabrication of scaffolds is time consuming and expensive, numerical methods are often utilized to simulate their mechanical properties in order to find a nearly optimum one. Finite element analysis is one of the most common numerical methods that is used in this regard. In this paper, a parametric finite element model is developed to assess the effects of layers penetration׳s effect on inter-layer adhesion, which is reflected on the mechanical properties of bone scaffolds. To be able to validate this model, some compression test specimens as well as bone scaffolds are fabricated with biocompatible and biodegradable poly lactic acid using fused deposition modeling. All these specimens are tested in compression and their elastic modulus is obtained. Using the material parameters of the compression test specimens, the finite element analysis of the bone scaffold is performed. The obtained elastic modulus is compared with experiment indicating a good agreement. Accordingly, the proposed finite element model is able to predict the mechanical behavior of fabricated bone scaffolds accurately. In addition, the effect of post-heating of bone scaffolds on their elastic modulus is investigated. The results demonstrate that the numerically predicted elastic modulus of scaffold is closer to experimental outcomes in comparison with as-built samples. PMID:26874065

  4. Computer modelling integrated with micro-CT and material testing provides additional insight to evaluate bone treatments: Application to a beta-glycan derived whey protein mice model.

    Science.gov (United States)

    Sreenivasan, D; Tu, P T; Dickinson, M; Watson, M; Blais, A; Das, R; Cornish, J; Fernandez, J

    2016-01-01

    The primary aim of this study was to evaluate the influence of a whey protein diet on computationally predicted mechanical strength of murine bones in both trabecular and cortical regions of the femur. There was no significant influence on mechanical strength in cortical bone observed with increasing whey protein treatment, consistent with cortical tissue mineral density (TMD) and bone volume changes observed. Trabecular bone showed a significant decline in strength with increasing whey protein treatment when nanoindentation derived Young׳s moduli were used in the model. When microindentation, micro-CT phantom density or normalised Young׳s moduli were included in the model a non-significant decline in strength was exhibited. These results for trabecular bone were consistent with both trabecular bone mineral density (BMD) and micro-CT indices obtained independently. The secondary aim of this study was to characterise the influence of different sources of Young׳s moduli on computational prediction. This study aimed to quantify the predicted mechanical strength in 3D from these sources and evaluate if trends and conclusions remained consistent. For cortical bone, predicted mechanical strength behaviour was consistent across all sources of Young׳s moduli. There was no difference in treatment trend observed when Young׳s moduli were normalised. In contrast, trabecular strength due to whey protein treatment significantly reduced when material properties from nanoindentation were introduced. Other material property sources were not significant but emphasised the strength trend over normalised material properties. This shows strength at the trabecular level was attributed to both changes in bone architecture and material properties. PMID:26599826

  5. In ovo feeding with minerals and vitamin D3 improves bone properties in hatchlings and mature broilers.

    Science.gov (United States)

    Yair, R; Shahar, R; Uni, Z

    2015-11-01

    The objective of this study was to examine the effect of in ovo feeding (IOF) with inorganic minerals or organic minerals and vitamin D3 on bone properties and mineral consumption. Eggs were incubated and divided into 4 groups: IOF with organic minerals, phosphate, and vitamin D3 (IOF-OMD); IOF with inorganic minerals and phosphate (IOF-IM); sham; and non-treated controls (NTC). IOF was performed on embryonic day (E) 17; tibiae and yolk samples were taken on E19 and E21. Post-hatch, only chicks from the IOF-OMD, sham, and NTC were raised, and tibiae were taken on d 10 and 38. Yolk mineral content was examined by inductively coupled plasma spectroscopy. Tibiae were tested for their whole-bone mechanical properties, and mid-diaphysis bone sections were indented in a micro-indenter to determine bone material stiffness (Young's modulus). Micro-computed tomography (μCT) was used to examine cortical and trabecular bone structure. Ash content analysis was used to examine bone mineralization. A latency-to-lie (LTL) test was used to measure standing ability of the d 38 broilers. The results showed that embryos from both IOF-OMD and IOF-IM treatments had elevated Cu, Mn, and Zn amounts in the yolk on E19 and E21 and consumed more of these minerals (between E19 and E21) in comparison to the sham and NTC. On E21, these hatchlings had higher whole-bone stiffness in comparison to the NTC. On d 38, the IOF-OMD had higher ash content, elevated whole-bone stiffness, and elevated Young's modulus (in males) in comparison to the sham and NTC; however, no differences in standing ability were found. Very few structural differences were seen during the whole experiment. This study demonstrates that mineral supplementation by in ovo feeding is sufficient to induce higher mineral consumption from the yolk, regardless of its chemical form or the presence of vitamin D3. Additionally, IOF with organic minerals and vitamin D3 can increase bone ash content, as well as stiffness of the whole

  6. Anisotropy of Magnetic Properties in Textured Materials

    OpenAIRE

    J. A. Szpunar

    1989-01-01

    A short survey is presented of techniques and methods used to correlate the texture with the magnetic anisotropy of various properties of soft and hard magnetic materials. Also, examples of magnetic materials are discussed with emphasis on techniques of processing which optimize the texture.

  7. Pulmonary bone cement embolism: CT angiographic evaluation with material decomposition using gemstone spectral imaging.

    Science.gov (United States)

    Huh, Sun; Lee, Heon

    2014-01-01

    We report a case of pulmonary bone cement embolism in a female who presented with dyspnea following multiple sessions of vertebroplasty. She underwent spectral CT pulmonary angiography and the diagnosis was made based on enhanced visualization of radiopaque cement material in the pulmonary arteries and a corresponding decrease in the parenchymal iodine content. Here, we describe the CT angiography findings of bone cement embolism with special emphasis on the potential benefits of spectral imaging, providing additional information on the material composition. PMID:25053903

  8. Pulmonary bone cement embolism: CT angiographic evaluation with material decomposition using gemstone special imaging

    Energy Technology Data Exchange (ETDEWEB)

    Huh, Sun; Lee, Heon [Dept. of Radiology, Soonchunhyang University Hospital Bucheon, Bucheon (Korea, Republic of)

    2014-08-15

    We report a case of pulmonary bone cement embolism in a female who presented with dyspnea following multiple sessions of vertebroplasty. She underwent spectral CT pulmonary angiography and the diagnosis was made based on enhanced visualization of radiopaque cement material in the pulmonary arteries and a corresponding decrease in the parenchymal iodine content. Here, we describe the CT angiography findings of bone cement embolism with special emphasis on the potential benefits of spectral imaging, providing additional information on the material composition.

  9. Pulmonary bone cement embolism: CT angiographic evaluation with material decomposition using gemstone special imaging

    International Nuclear Information System (INIS)

    We report a case of pulmonary bone cement embolism in a female who presented with dyspnea following multiple sessions of vertebroplasty. She underwent spectral CT pulmonary angiography and the diagnosis was made based on enhanced visualization of radiopaque cement material in the pulmonary arteries and a corresponding decrease in the parenchymal iodine content. Here, we describe the CT angiography findings of bone cement embolism with special emphasis on the potential benefits of spectral imaging, providing additional information on the material composition.

  10. Effect of nanofillers on the physico-mechanical properties of load bearing bone implants.

    Science.gov (United States)

    Michael, Feven Mattews; Khalid, Mohammad; Walvekar, Rashmi; Ratnam, Chantara Thevy; Ramarad, Suganti; Siddiqui, Humaira; Hoque, M Enamul

    2016-10-01

    Bones are nanocomposites consisting of a collagenous fibre network, embedded with calcium phosphates mainly hydroxyapatite (HA) nanocrystallites. As bones are subjected to continuous loading and unloading process every day, they often tend to become prone to fatigue and breakdown. Therefore, this review addresses the use of nanocomposites particularly polymers reinforced with nanoceramics that can be used as load bearing bone implants. Further, nanocomposite preparation and dispersion modification techniques have been highlighted along with thorough discussion on the influence that various nanofillers have on the physico-mechanical properties of nanocomposites in relation to that of natural bone properties. This review updates the nanocomposites that meet the physico-mechanical properties (strength and elasticity) as well as biocompatibility requirement of a load bearing bone implant and also attempts to highlight the gaps in the reported studies to address the fatigue and creep properties of the nanocomposites. PMID:27287178

  11. [EFFECT OF MELATONIN ON AGE-RELATED DYNAMICS OF THE REACTIVE PROPERTIES OF BONE TISSUE].

    Science.gov (United States)

    Levashov, M I; Chaka, E G; Yanko, R V; Zamorska, T M

    2015-10-01

    The effect of melatonin (MT) on the bone tissue (BT) reactive properties was investigated among 80 male Wistar rats at the age of 3, 9, 12 and 16 months. The reactive properties of BT were judged by its ability to polarization under the influence of the alternating electric current. The value of reactance at the frequency of maximum polarization was used as the indicator of BT reactivity. Experimental animals received daily melatonin (Unipharm Inc., USA) at the rate of 1 mg/kg of body mass for 28 days. Freshly isolated femurs of rats served as a material for investigation. Introduction of MT to rats resulted in a significant increase in bone mass and polarization properties of BT. However, the clear tendency to increase the reactance not more than 2.2 % (p reactance among 9 and 12-month old rats were 6.3% and 12.1% (p reactance increased by 21.8% (p < 0.05) among 15-month old animals. Thus the introduction of MT increased the reactivity of BT. This effect had a clear dependence on the age and appeared more among older animals. PMID:26827497

  12. Optical properties of low-dimensional materials

    CERN Document Server

    Ogawa, T

    1998-01-01

    This book surveys recent theoretical and experimental studies of optical properties of low-dimensional materials. As an extended version of Optical Properties of Low-Dimensional Materials (Volume 1, published in 1995 by World Scientific), Volume 2 covers a wide range of interesting low-dimensional materials including both inorganic and organic systems, such as disordered polymers, deformable molecular crystals, dilute magnetic semiconductors, SiGe/Si short-period superlattices, GaAs quantum wires, semiconductor microcavities, and photonic crystals. There are excellent review articles by promis

  13. Bioactive glasses materials, properties and applications

    CERN Document Server

    Ylänen, Heimo

    2011-01-01

    Due to their biocompatibility and bioactivity, bioactive glasses are used as highly effective implant materials throughout the human body to replace or repair damaged tissue. As a result, they have been in continuous use since shortly after their invention in the late 1960s and are the subject of extensive research worldwide.Bioactive glasses provides readers with a detailed review of the current status of this unique material, its properties, technologies and applications. Chapters in part one deal with the materials and mechanical properties of bioactive glass, examining topics such

  14. Bone grafting: An overview

    Directory of Open Access Journals (Sweden)

    D. O. Joshi

    2010-08-01

    Full Text Available Bone grafting is the process by which bone is transferred from a source (donor to site (recipient. Due to trauma from accidents by speedy vehicles, falling down from height or gunshot injury particularly in human being, acquired or developmental diseases like rickets, congenital defects like abnormal bone development, wearing out because of age and overuse; lead to bone loss and to replace the loss we need the bone grafting. Osteogenesis, osteoinduction, osteoconduction, mechanical supports are the four basic mechanisms of bone graft. Bone graft can be harvested from the iliac crest, proximal tibia, proximal humerus, proximal femur, ribs and sternum. An ideal bone graft material is biologically inert, source of osteogenic, act as a mechanical support, readily available, easily adaptable in terms of size, shape, length and replaced by the host bone. Except blood, bone is grafted with greater frequency. Bone graft indicated for variety of orthopedic abnormalities, comminuted fractures, delayed unions, non-unions, arthrodesis and osteomyelitis. Bone graft can be harvested from the iliac crest, proximal tibia, proximal humerus, proximal femur, ribs and sternum. By adopting different procedure of graft preservation its antigenicity can be minimized. The concept of bone banking for obtaining bone grafts and implants is very useful for clinical application. Absolute stability require for successful incorporation. Ideal bone graft must possess osteogenic, osteoinductive and osteocon-ductive properties. Cancellous bone graft is superior to cortical bone graft. Usually autologous cancellous bone graft are used as fresh grafts where as allografts are employed as an alloimplant. None of the available type of bone grafts possesses all these properties therefore, a single type of graft cannot be recomm-ended for all types of orthopedic abnormalities. Bone grafts and implants can be selected as per clinical problems, the equipments available and preference of

  15. Mutual associations among microstructural, physical and mechanical properties of human cancellous bone

    DEFF Research Database (Denmark)

    Ding, Ming; Odgaard, A; Danielsen, CC; Hvid, I

    2002-01-01

    structure and mechanical properties. In this study, 160 cancellous bone specimens were produced from 40 normal human tibiae aged from 16 to 85 years at post-mortem. The specimens underwent micro-CT and the microstructural properties were calculated using unbiased three-dimensional methods. The specimens...... were tested to determine the mechanical properties and the physical/compositional properties were evaluated. The type of structure together with anisotropy correlated well with Young's modulus of human tibial cancellous bone. The plate-like structure reflected high mechanical stress and the rod......-like structure low mechanical stress. There was a strong correlation between the type of trabecular structure and the bone-volume fraction. The most effective microstructural properties for predicting the mechanical properties of cancellous bone seem to differ with age....

  16. Tooth Movement out of the Bony Wall Using Augmented Corticotomy with Nonautogenous Graft Materials for Bone Regeneration

    OpenAIRE

    Kye-Bok Lee; Dong-Yeol Lee; Hyo-Won Ahn; Seong-Hun Kim; Eun-Cheol Kim; Igor Roitman

    2014-01-01

    This prospective randomized split-mouth study was performed to compare the effects of augmented corticotomy with those of different nonautogenous bone graft materials combined with orthodontic tooth movement in dogs. Decortication was performed on the buccal bone surface of 6 male beagle dogs that were randomly assigned to receive grafts of deproteinized bovine bone mineral, irradiated cortical bone, or synthetic bone. Immediate orthodontic force was applied to the second and third premolars ...

  17. Tissue reactions to particles of bone-substitute materials in intraosseous and heterotopic sites in rats: discrimination of osteoinduction, osteocompatibility, and inflammation.

    Science.gov (United States)

    Eid, K; Zelicof, S; Perona, B P; Sledge, C B; Glowacki, J

    2001-09-01

    Two rat models were used to characterize tissue-specific reactions to particles of bone-substitute materials: one for osteocompatibility in a healing tibial wound and the other in a heterotopic, subcutaneous site. Small, unicortical tibial wounds in rats healed spontaneously, beginning with the rapid proliferation of intramedullary woven bone. That temporary bone was resorbed by osteoclasts and finally, the cortical wound was healed with lamellar bone and the medullary space was repopulated with marrow. When various particulate materials were implanted into fresh wounds, three types of reactions were observed. (1) Demineralized bone powder (DBP) and non-resorbable calcium phosphate (nrCP) were incorporated into the reactive medullary and cortical bone. (2) Polymethylmetlhacrylate (PMMA) particles were surrounded with a fibrous layer, but did not impair bone healing. (3) Polyethylene (PE) shards and resorbable calcium phosphates (rCPs) were inflammatory and inhibited osseous repair. Subcutaneous sites showed osteoinductive, fibrotic, or inflammatory responses to these materials. Only DBP induced endochondral osteogenesis subcutaneously. The nrCP evoked a fibrous reaction. In contrast, rCPs, PMMA, and PE shards generated inflammatory reactions with each particle being surrounded by fibrous tissue and large multinucleated giant cells. In conclusion, only DBP showed osteoinductive as well as osteocompatible properties. The nrCP was osteocompatible. The rCPs stimulated various degrees of inflammatory responses. PMMA was osteocompatible and did not interfere with the bone healing process. PE was not osteocompatible and generated foreign body reactions in both sites. Use of the two sites distinguishes osteoinductive, osteocompatible, and inflammatory properties of particles of bone-substitute materials. PMID:11562148

  18. Bone

    International Nuclear Information System (INIS)

    Bone scanning provides information on the extent of primary bone tumors, on possible metastatic disease, on the presence of osteomyelitis prior to observation of roentgenographic changes so that earlier therapy is possible, on the presence of collagen diseases, on the presence of fractures not disclosed by x-ray films, and on the evaluation of aseptic necrosis. However, the total effect and contribution of bone scanning to the diagnosis, treatment, and ultimate prognosis of pediatric skeletal diseases is, as yet, unknown. (auth)

  19. Multifunctional Polycrystalline Ferroelectric Materials Processing and Properties

    CERN Document Server

    Pardo, Lorena

    2011-01-01

    This book presents selected topics on processing and properties of ferroelectric materials that are currently the focus of attention in scientific and technical research. Ferro-piezoelectric ceramics are key materials in devices for many applications, such as automotive, healthcare and non-destructive testing. As they are polycrystalline, non-centrosymmetric materials, their piezoelectricity is induced by the so-called poling process. This is based on the principle of polarization reversal by the action of an electric field that characterizes the ferroelectric materials. This book was born with the aim of increasing the awareness of the multifunctionality of ferroelectric materials among different communities, such as researchers, electronic engineers, end-users and manufacturers, working on and with ferro-piezoelectric ceramic materials and devices which are based on them. The initiative to write this book comes from a well-established group of researchers at the Laboratories of Ferroelectric Materials, Mate...

  20. Bone properties surrounding hydroxyapatite-coated custom osseous integrated dental implants.

    Science.gov (United States)

    Baker, M I; Eberhardt, A W; Martin, D M; McGwin, G; Lemons, J E

    2010-10-01

    Calcium phosphate (hydroxyapatite or HA) coatings have been applied to Custom Osseous Integrated Implants (COIIs) to improve the quality of the bone-implant integration, yet little is known concerning the biomechanical properties of bone surrounding the HA-coated implants in humans over the long term. The purpose of this study was to characterize the mechanical and histomorphometric properties of the bone along the implant interface. Specimens were prepared from three similar mandibular implants that were functional in three female patients for about 11 years. Histomorphometric analyses showed bone-implant contact averaging 75% for all specimens. Area coverage of residual HA-coating ranged from 52 to 70%. When compared with previous studies, these results show a relatively high percentage of residual HA after a decade in vivo. Nanoindentation showed similar average values of hardness and modulus (p = 0.53 and p = 0.56, respectively) comparing bone adjacent to residual HA-coating and regions where the coating was absent. The elastic modulus was significantly lower for bone near the bone-implant interface (1000 μm) from the interface (p = 0.05), thereby reflecting different properties of the bone near these interfaces. Backscattered electron imaging showed darker gray levels which indicated decreased mineral content in bone adjacent to the implant, consistent with the nanoindentation results. PMID:20725958

  1. Effect of biomaterial properties on bone healing in a rabbit tooth extraction socket model

    NARCIS (Netherlands)

    Fisher, J.P.; Lalani, Z.; Bossano, C.M.; Brey, E.M.; Demian, N.; Johnston, C.M.; Dean, D.; Jansen, J.A.; Wong, M.E.; Mikos, A.G.

    2004-01-01

    In this work we sought to understand the effect of biomaterial properties upon healing bone tissue. We hypothesized that a hydrophilic polymer gel implanted into a bone tissue defect would impede the healing process owing to the biomaterial's prevention of protein adsorption and thus cell adhesion.

  2. Mechanical properties of cancellous bone in the human mandibular condyle are anisotropic

    DEFF Research Database (Denmark)

    Giesen, EB; Ding, Ming; Dalstra, M; van Eijden, TM

    2001-01-01

    ). Archimedes' principle was applied to determine bone density parameters. The cancellous bone was in axial loading 3.4 times stiffer and 2.8 times stronger upon failure than in transverse loading. High coefficients of correlation were found among the various mechanical properties and between them and the...

  3. Reloading partly recovers bone mineral density and mechanical properties in hind limb unloaded rats

    Science.gov (United States)

    Zhao, Fan; Li, Dijie; Arfat, Yasir; Chen, Zhihao; Liu, Zonglin; Lin, Yu; Ding, Chong; Sun, Yulong; Hu, Lifang; Shang, Peng; Qian, Airong

    2014-12-01

    Skeletal unloading results in decreased bone formation and bone mass. During long-term space flight, the decreased bone mass is impossible to fully recover. Therefore, it is necessary to develop the effective countermeasures to prevent spaceflight-induced bone loss. Hindlimb Unloading (HLU) simulates effects of weightlessness and is utilized extensively to examine the response of musculoskeletal systems to certain aspects of space flight. The purpose of this study is to investigate the effects of a 4-week HLU in rats and subsequent reloading on the bone mineral density (BMD) and mechanical properties of load-bearing bones. After HLU for 4 weeks, the rats were then subjected to reloading for 1 week, 2 weeks and 3 weeks, and then the BMD of the femur, tibia and lumbar spine in rats were assessed by dual energy X-ray absorptiometry (DXA) every week. The mechanical properties of the femur were determined by three-point bending test. Dry bone and bone ash of femur were obtained through Oven-Drying method and were weighed respectively. Serum alkaline phosphatase (ALP) and serum calcium were examined through ELISA and Atomic Absorption Spectrometry. The results showed that 4 weeks of HLU significantly decreased body weight of rats and reloading for 1 week, 2 weeks or 3 weeks did not recover the weight loss induced by HLU. However, after 2 weeks of reloading, BMD of femur and tibia of HLU rats partly recovered (+10.4%, +2.3%). After 3 weeks of reloading, the reduction of BMD, energy absorption, bone mass and mechanical properties of bone induced by HLU recovered to some extent. The changes in serum ALP and serum calcium induced by HLU were also recovered after reloading. Our results indicate that a short period of reloading could not completely recover bone after a period of unloading, thus some interventions such as mechanical vibration or pharmaceuticals are necessary to help bone recovery.

  4. Overexpression of DMP1 accelerates mineralization and alters cortical bone biomechanical properties in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Bhatia A.; Miller L.; Albazza, M.; Espinoza Orias, A.A.; Inoue, N.; Acerbo, A.; George, A.; Sumner, D.R.

    2011-09-29

    Dentin matrix protein-1 (DMP1) is a key regulator of biomineralization. Here, we examine changes in structural, geometric, and material properties of cortical bone in a transgenic mouse model overexpressing DMP1. Micro-computed tomography and three-point bending were performed on 90 femora of wild type and transgenic mice at 1, 2, 4, and 6 months. Fourier transform infrared imaging was performed at 2 months. We found that the transgenic femurs were longer (p < 0.01), more robust in cross-section (p < 0.05), stronger (p < 0.05), but had less post-yield strain and displacement (p < 0.01), and higher tissue mineral density (p < 0.01) than the wild type femurs at 1 and 2 months. At 2 months, the transgenic femurs also had a higher mineral-to-matrix ratio (p < 0.05) and lower carbonate substitution (p < 0.05) compared to wild type femurs. These findings indicate that increased mineralization caused by overexpressing DMP1 led to increased structural cortical bone properties associated with decreased ductility during the early post-natal period.

  5. Effects of bone materials on the screw pull-out strength in human spine.

    Science.gov (United States)

    Zhang, Qing Hang; Tan, Soon Huat; Chou, Siaw Meng

    2006-10-01

    A three-dimensional finite element model simulating the threaded connections including detailed helix curve for the bone and surgical screw was constructed. Validation of the FE model was conducted by comparing the predicted screw pull-out strength in different foam materials against experimental study. The FE model was then further analyzed to investigate the interaction of bone material and purchase length on the screw pull-out strength. The results show that failure of the connection was due to bone shearing which occurred along a cylindrical surface determined by the outer perimeter of the screw. The cortical shell resists around 50% of the pull-out strength for a screw of 4mm in major diameter and 22 mm in length. The effects of purchase length on the pull-out strength were different for different bone material. It is the bone material that determines the stability of the inserted surgical screw. The significance of the purchase length on the pull-out strength of cortical screw will be much lower than that in cancellous bone screw. PMID:16414303

  6. An alternative ultrasonic method for measuring the elastic properties of cortical bone

    CERN Document Server

    Pithioux, M; Chabrand, P; Pithioux, Martine

    2002-01-01

    We studied the elastic properties of bone to analyze its mechanical behavior. The basic principles of ultrasonic methods are now well established for varying isotropic media, particularly in the field of biomedical engineering. However, little progress has been made in its application to anisotropic materials. This is largely due to the complex nature of wave propagation in these media. In the present study, the theory of elastic waves is essential because it relates the elastic moduli of a material to the velocity of propagation of these waves along arbitrary directions in a solid. Transducers are generally placed in contact with the samples which are often cubes with parallel faces that are difficult to prepare. The ultrasonic method used here is original, a rough preparation of the bone is sufficient and the sample is in rotation. Moreover, to analyze heterogeneity of the structure we measure velocities in different points on the sample. The aim of the present study was to determine in vitro the anisotropi...

  7. Comparison about the bone material examination of JIS and ISO; Honezai shiken ni kansuru JIS to ISO no hikaku

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Sumie.; Yanagi, Kei.; Shimura, Akiharu.; Murohoshi, Shiori. [Japan Testing Center for Construction Materials, Tokyo (Japan)

    1998-12-01

    There are various things in slug bone material and so on manufactured from the macadam, crumble sand. Which crushed rock including gravel, sand to produce in the nature and which was manufactured, and a lightweight bone material and the industry by-product with the bone material used for the concrete. It is necessary with a bone material to grasp the nature of the bone material itself properly to occupy about 70% of the capacity in the concrete and to manufacture the good concrete of the quality from the influence that influence to the various concrete materiality that quality being big. When the quality of a bone material to use for the concrete is confirmed, an examination is being done in accordance with the way of examining it established as the Japanese industry standard in our country. (NEDO)

  8. Modifications of histamine receptor signaling affect bone mechanical properties in rats.

    Science.gov (United States)

    Folwarczna, Joanna; Janas, Aleksandra; Pytlik, Maria; Śliwiński, Leszek; Wiercigroch, Marek; Brzęczek, Anna

    2014-02-01

    Histamine receptors are expressed on bone cells and histamine may be involved in regulation of bone metabolism. The aim of the present study was to investigate the effects of loratadine (an H(1) receptor antagonist), ranitidine (an H(2) receptor antagonist) and betahistine (an H(3) receptor antagonist and H(1) receptor agonist) on bone mechanical properties in rats. Loratadine (5 mg/kg/day, po), ranitidine (50 mg/kg/day, po), or betahistine dihydrochloride (5 mg/kg/day, po), were administered for 4 weeks to non-ovariectomized and bilaterally ovariectomized (estrogen-deficient) 3-month-old rats, and their effects were compared with appropriate controls. Serum levels of bone turnover markers, bone mineralization and mechanical properties of the proximal tibial metaphysis, femoral diaphysis and femoral neck were studied. In rats with normal estrogen level, administration of loratadine slightly favorably affected mechanical properties of compact bone, significantly increasing the strength of the femoral neck (p < 0.05), and tending to increase the strength of the femoral diaphysis. Ranitidine did not significantly affect the investigated parameters, and betahistine decreased the strength of the tibial metaphysis (cancellous bone, p < 0.01). There were no significant effects of the drugs on serum bone turnover markers. In estrogen-deficient rats, the drugs did not significantly affect the investigated skeletal parameters. In conclusion, the effects of histamine H(1), H(2) and H(3) receptor antagonists on the skeletal system in rats were differential and dependent on estrogen status. PMID:24905313

  9. Silver-Doped Calcium Phosphate Bone Cements with Antibacterial Properties

    Science.gov (United States)

    Rau, J. V.; Fosca, M.; Graziani, V.; Egorov, A. A.; Zobkov, Yu. V.; Fedotov, A. Yu.; Ortenzi, M.; Caminiti, R.; Baranchikov, A. E.; Komlev, V. S.

    2016-01-01

    Calcium phosphate bone cements (CPCs) with antibacterial properties are demanded for clinical applications. In this study, we demonstrated the use of a relatively simple processing route based on preparation of silver-doped CPCs (CPCs-Ag) through the preparation of solid dispersed active powder phase. Real-time monitoring of structural transformations and kinetics of several CPCs-Ag formulations (Ag = 0 wt %, 0.6 wt % and 1.0 wt %) was performed by the Energy Dispersive X-ray Diffraction technique. The partial conversion of β-tricalcium phosphate (TCP) phase into the dicalcium phosphate dihydrate (DCPD) took place in all the investigated cement systems. In the pristine cement powders, Ag in its metallic form was found, whereas for CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt % cements, CaAg(PO3)3 was detected and Ag (met.) was no longer present. The CPC-Ag 0 wt % cement exhibited a compressive strength of 6.5 ± 1.0 MPa, whereas for the doped cements (CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt %) the reduced values of the compressive strength 4.0 ± 1.0 and 1.5 ± 1.0 MPa, respectively, were detected. Silver-ion release from CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt % cements, measured by the Atomic Emission Spectroscopy, corresponds to the average values of 25 µg/L and 43 µg/L, respectively, rising a plateau after 15 days. The results of the antibacterial test proved the inhibitory effect towards pathogenic Escherichia coli for both CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt % cements, better performances being observed for the cement with a higher Ag-content. PMID:27096874

  10. Extraction and characterisation of apatite- and tricalcium phosphate-based materials from cod fish bones

    International Nuclear Information System (INIS)

    Apatite- and tricalcium phosphate-based materials were produced from codfish bones, thus converting a waste by-product from the food industry into high added-valued compounds. The bones were annealed at temperatures between 900 and 1200 °C, giving a biphasic material of hydroxyapatite and tricalcium phosphate (Ca10(PO4)6(OH)2 and β-Ca(PO4)3) with a molar proportion of 75:25, a material widely used in biomedical implants. The treatment of the bones in solution prior to their annealing changed the composition of the material. Single phase hydroxyapatite, chlorapatite (Ca10(PO4)6Cl2) and fluorapatite (Ca10(PO4)6F2) were obtained using CaCl2 and NaF solutions, respectively. The samples were analysed by several techniques (X-ray diffraction, infrared spectroscopy, scanning electron microscopy and differential thermal/thermogravimetric analysis) and by elemental analyses, to have a more complete understanding of the conversion process. Such compositional modifications have never been performed before for these materials of natural origin to tailor the relative concentrations of elements. This paper shows the great potential for the conversion of this by-product into highly valuable compounds for biomedical applications, using a simple and effective valorisation process. - Highlights: ► Apatite and calcium phosphate compounds extraction from cod fish bonesBone calcination: biphasic material hydroxyapatite-calcium phosphate production ► Bone pre-treatments in solution change the material composition. ► Single phase materials (hydroxy-, chloro- or fluoroapatite) are obtained. ► Concentration of other elements (Na, F, Cl) suitable for biomedical applications

  11. Extraction and characterisation of apatite- and tricalcium phosphate-based materials from cod fish bones

    Energy Technology Data Exchange (ETDEWEB)

    Piccirillo, C.; Silva, M.F. [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal); Pullar, R.C. [Dept. Engenharia de Materiais e Ceramica/CICECO, Universidade de Aveiro, Aveiro (Portugal); Braga da Cruz, I. [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal); WeDoTech, CiDEB/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal); Jorge, R. [WeDoTech, CiDEB/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal); Pintado, M.M.E. [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal); Castro, P.M.L., E-mail: plcastro@porto.ucp.pt [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal)

    2013-01-01

    Apatite- and tricalcium phosphate-based materials were produced from codfish bones, thus converting a waste by-product from the food industry into high added-valued compounds. The bones were annealed at temperatures between 900 and 1200 Degree-Sign C, giving a biphasic material of hydroxyapatite and tricalcium phosphate (Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2} and {beta}-Ca(PO{sub 4}){sub 3}) with a molar proportion of 75:25, a material widely used in biomedical implants. The treatment of the bones in solution prior to their annealing changed the composition of the material. Single phase hydroxyapatite, chlorapatite (Ca{sub 10}(PO{sub 4}){sub 6}Cl{sub 2}) and fluorapatite (Ca{sub 10}(PO{sub 4}){sub 6}F{sub 2}) were obtained using CaCl{sub 2} and NaF solutions, respectively. The samples were analysed by several techniques (X-ray diffraction, infrared spectroscopy, scanning electron microscopy and differential thermal/thermogravimetric analysis) and by elemental analyses, to have a more complete understanding of the conversion process. Such compositional modifications have never been performed before for these materials of natural origin to tailor the relative concentrations of elements. This paper shows the great potential for the conversion of this by-product into highly valuable compounds for biomedical applications, using a simple and effective valorisation process. - Highlights: Black-Right-Pointing-Pointer Apatite and calcium phosphate compounds extraction from cod fish bones Black-Right-Pointing-Pointer Bone calcination: biphasic material hydroxyapatite-calcium phosphate production Black-Right-Pointing-Pointer Bone pre-treatments in solution change the material composition. Black-Right-Pointing-Pointer Single phase materials (hydroxy-, chloro- or fluoroapatite) are obtained. Black-Right-Pointing-Pointer Concentration of other elements (Na, F, Cl) suitable for biomedical applications.

  12. Static mechanical properties of buffer material

    International Nuclear Information System (INIS)

    The buffer material is expected to maintain its low water permeability, self-sealing properties, radionuclides adsorption and retardation properties, thermal conductivity, chemical buffering properties, overpack supporting properties, stress buffering properties, etc. over a long period of time. Natural clay is mentioned as a material that can relatively satisfy above. Among the kinds of natural clay, bentonite when compacted is superior because (i) it has exceptionally low water permeability and properties to control the movement of water in buffer, (ii) it fills void spaces in the buffer and fractures in the host rock as it swells upon water uptake, (iii) it has the ability to exchange cations and to adsorb cationic radioelements. In order to confirm these functions for the purpose of safety assessment, it is necessary to evaluate buffer properties through laboratory tests and engineering-scale tests, and to make assessments based on the ranges in the data obtained. This report describes the procedures, test conditions, results and examinations on the buffer material of unconfined compression tests, one-dimensional consolidation tests, consolidated-undrained triaxial compression tests and consolidated-undrained triaxial creep tests that aim at getting hold of static mechanical properties. We can get hold of the relationship between the dry density and tensile stress etc. by Brazilian tests, between the dry density and unconfined compressive strength etc. by unconfined compression tests, between the consolidation stress and void ratio etc. by one-dimensional consolidation tests, the stress pass of each effective confining pressure etc. by consolidated-undrained triaxial compression tests and the axial strain rate with time of each axial stress etc. by consolidated-undrained triaxial creep tests. (author)

  13. Effects of Materials of Cementless Femoral Stem on the Functional Adaptation of Bone

    Institute of Scientific and Technical Information of China (English)

    He Gong; Wei Wu; Juan Fang; Xin Dong; Meisheng Zhao; Tongtong Guo

    2012-01-01

    The objective of this paper is to identify the effects of materials of cementless femoral stem on the functional adaptive behaviors of bone.The remodeling behaviors of a two-dimensional simplified model of cementless hip prosthesis with stiff stem,flexible 'iso-elastic' stem,one-dimensional Functionally Graded Material (FGM) stem and two-dimensional FGM stem for the period of four years after prosthesis replacement were quantified by incorporating the bone remodeling algorithm with finite element analysis.The distributions of bone density,von Mises stress,and interface shear stress were obtained.The results show that two-dimensional FGM stem may produce more mechanical stimuli and more uniform interface shear stress compared with the stems made of other materials,thus the host bone is well preserved.Accordingly,the two-dimensional FGM stem is an appropriate femoral implant from a biomechanical point of view.The numerical simulation in this paper can provide a quantitative computational paradigm for the changes of bone morphology caused by implants,which can help to improve the design of implant to reduce stress shielding and the risk of bone-prosthesis interface failure.

  14. Interface Properties in Extruded FRC-Materials

    DEFF Research Database (Denmark)

    Stang, Henrik

    1997-01-01

    In a research and development project recently carried out at Department of Structural Engineering and Materials, Technical University of Denmark a new extrusion process for HPFRCC-materials was demonstrated.It is shown that superior interfacial properties are obtained in a polypropylene fiber...... reinforced cementitious material extruded by the developed process. It is further more shown that the fiber-matrix bond is highly dependent on the relative slip at the interface and a bond-slip relationship is suggested for the extruded material. The observed very high fiber-matrix bond is explained by the...... densification of the interfacial matrix material which has taken place during the consolidation process and which can be observed in the thin-section analysis....

  15. Porous poly(vinyl alcohol)/sepiolite bone scaffolds: Preparation, structure and mechanical properties

    International Nuclear Information System (INIS)

    Porous poly(vinyl alcohol) (PVA)/sepiolite nanocomposite scaffolds containing 0–10 wt.% sepiolite were prepared by freeze-drying and thermally crosslinked with poly(arylic acid). The microstructure of the obtained scaffolds was characterised by scanning electron microscopy and micro-computed tomography, which showed a ribbon and ladder like interconnected structure. The incorporation of sepiolite increased the mean pore size and porosity of the PVA scaffold as well as the degree of anisotropy due to its fibrous structure. The tensile strength, modulus and energy at break of the PVA solid material that constructed the scaffold were found to improve with additions of sepiolite by up to 104%, 331% and 22% for 6 wt.% clay. Such enhancements were attributed to the strong interactions between the PVA and sepiolite, the good dispersion of sepiolite nanofibres in the matrix and the intrinsic properties of the nanofibres. However, the tensile properties of the PVA scaffold deteriorated in the presence of sepiolite because of the higher porosity, pore size and degree of anisotropy. The PVA/sepiolite nanocomposite scaffold containing 6 wt.% sepiolite was characterised by an interconnected structure, a porosity of 89.5% and a mean pore size of 79 μm and exhibited a tensile strength of 0.44 MPa and modulus of 14.9 MPa, which demonstrates potential for this type of materials to be further developed as bone scaffolds. - Highlights: ► Novel PAA-crosslinked PVA/sepiolite nanocomposite scaffolds were prepared. ► They were highly porous with interconnected structures and exhibited good mechanical properties. ► The effects of sepiolite nanofibres on structure and properties of the scaffolds were investigated. ► Sepiolite nanofibres improved the mechanical properties of the solid material significantly.

  16. Bone cells in cultures on nanocarbon-based materials for potential bone tissue engineering: A review

    Czech Academy of Sciences Publication Activity Database

    Bačáková, Lucie; Kopová, Ivana; Staňková, Ľubica; Lišková, Jana; Vacík, Jiří; Lavrentiev, Vasyl; Kromka, Alexander; Potocký, Štěpán; Stránská, D.

    2014-01-01

    Roč. 211, č. 12 (2014), s. 2688-2702. ISSN 1862-6300 R&D Projects: GA ČR(CZ) GAP108/12/1168; GA ČR(CZ) GA14-04790S; GA MŠk(CZ) ED1.1.00/02.0109; GA MŠk(CZ) EE2.3.30.0025 Institutional support: RVO:67985823 ; RVO:68378271 ; RVO:61389005 Keywords : biocompatibility * bone implants * carbon * nanoparticles Subject RIV: EI - Biotechnology ; Bionics Impact factor: 1.616, year: 2014

  17. Informatics derived materials databases for multifunctional properties

    International Nuclear Information System (INIS)

    In this review, we provide an overview of the development of quantitative structure–property relationships incorporating the impact of data uncertainty from small, limited knowledge data sets from which we rapidly develop new and larger databases. Unlike traditional database development, this informatics based approach is concurrent with the identification and discovery of the key metrics controlling structure–property relationships; and even more importantly we are now in a position to build materials databases based on design ‘intent’ and not just design parameters. This permits for example to establish materials databases that can be used for targeted multifunctional properties and not just one characteristic at a time as is presently done. This review provides a summary of the computational logic of building such virtual databases and gives some examples in the field of complex inorganic solids for scintillator applications. (review)

  18. Data base on structural materials aging properties

    Energy Technology Data Exchange (ETDEWEB)

    Oland, C.B.

    1992-03-01

    The US Nuclear Regulatory Commission has initiated a Structural Aging Program at the Oak Ridge National Laboratory to identify potential structural safety issues related to continued service of nuclear power plants and to establish criteria for evaluating and resolving these issues. One of the tasks in this program focuses on the establishment of a Structural Materials Information Center where long-term and environment-dependent properties of concretes and other structural materials are being collected and assembled into a data base. These properties will be used to evaluate the current condition of critical structural components in nuclear power plants and to estimate the future performance of these materials during the continued service period.

  19. The metabolic properties of plutonium and allied materials

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, J.G.

    1949-11-16

    This report summarizes radioautographic, tracer, decontamination, and bone metabolism studies done in 1949 on rats using plutonium and allied materials: Iodine 131; zirconium 95; niobium 95; cerium 144; samarium 153; selenium 75; rhodium 105. 4 figs., 9 tabs.

  20. Heat-deproteinated xenogeneic bone from slaughterhouse waste: Physico-chemical properties

    Indian Academy of Sciences (India)

    R Murugan; K Panduranga Rao; T S Sampath Kumar

    2003-08-01

    Xenogeneic bone procured from the slaughterhouse waste was deproteinated by heat treatment method intended for use as a bone substitute. The effect of heat treatment was investigated by thermal analysis and by physico-chemical methods such as X-ray powder diffraction (XRD) and Fourier transformed infrared (FTIR) spectroscopy. The heat treatment temperatures for the bovine bone samples were predetermined by thermogravimetric (TG) analysis. The XRD results revealed that the process of heat treatment promoted the crystallinity of bone samples, particularly at 700 and 900°C. There was no secondary phase transformation detected for heat-deproteinated bone except the presence of the hydroxyapatite (HA) phase, which indicated its phase purity even at a higher temperature. The FTIR spectra of raw bone and bone heated at 300°C indicated the presence of organic macromolecules whereas these disappeared in the samples heated at 500, 700 and 900°C, which suggested the removal of antigenic organic matters around 500°C. The same results were also confirmed quantitatively by calculating the amount of collagen using hydroxyproline estimation. There was no significant change in the TG-thermogram of bone heated at 500, 700 and 900°C, which indicated their thermal stability. These findings implied that the heat treated bone at 500°C had properties similar to carbonated HA with low crystallinity, while 700 and 900°C samples had the same with higher crystallinity. As low temperature treatment does not alter morphological and structural properties, we propose that the 500°C heat treated xenogeneic bone may act as an excellent osteogenic bone substitute.

  1. New bone implant material with calcium sulfate and Ti modified hydroxyapatite

    OpenAIRE

    A. Ślósarczyk; J. Czechowska; Z. Paszkiewicz; A. Zima

    2010-01-01

    (TiHA) to develop a novel bone cement. Results of previous studies showed that bioactive potential of titanium modified hydroxyapatite ceramics is higher than that of pure HA. Calcium sulfate hemihydrate is also considered as a safe, biocompatible material, however it has been criticized for its rapid resorption. Combination of these materials may result in new cement type material with surgical handiness and selective resorption.Design/methodology/approach: TiHA was obtained by a wet method....

  2. Study on Microstructure and Nanomechanics Properties of Antibacterial Bone China

    Institute of Scientific and Technical Information of China (English)

    Zhang Zhenyu; Li Hongqi; Zhang Jin; Zhou Hongxiu; Wang Lijuan; Zhang Taihua

    2004-01-01

    Fracture appearance, surface and nanomechanics properties of antibacterial ceramics contairing rare earth phosphate composite antibacterial materials were characterized and measured by SEM, AFM and Nanoindenter, respectively. Results show that grain of fracture surface of antibacterial ceramics grows uniform refinement topography of bubble break-up appears at the surface, which is flat and has liquid character, by adding the phosphate composite containing rare earth, nevertheless needle-like crystal and granular outgrowth form at fracture surface and surface of common ceramics, respectively. Young's modulus of antibacterial ceramic film is 74. 397 GPa and hardness is 8. 134 GPa, which increses by 4.4% and 1.6% comparing with common ceramics, respectively. Loading curves of two kind of ceramics have obvious nonlinear character under 700 nm and linear character between 700 ~ 1000 nm, and unloading curve have obvious linear character.

  3. Indirect sinus lift without bone graft material: systematic review and meta-analysis

    OpenAIRE

    Pérez Martínez, Sara; Martorell Calatayud, Luis; Peñarrocha Oltra, David; García Mira, Berta; Peñarrocha Diago, Miguel

    2015-01-01

    A systematic literature review and a meta-analysis of indirect sinus lift without the use of bone graft material was performed. A PubMed search was made from January 2005 to January 2012 with keywords: “sinus lift”, “osteotome”, “graft” and “maxillary sinus elevation”. The inclusion criteria were: maxillary sinus lift technique with osteotomes with a minimum follow-up period of 5 months after surgery without bone graft material. 11 articles were included. The mean gain in residual crestal bon...

  4. The European Fusion Material properties database

    International Nuclear Information System (INIS)

    Materials research represents a significant part of the European and world effort on fusion research. A European Fusion Materials web-based relational database is being developed to collect, expand and preserve for the future the data produced in support of the NET, DEMO and ITER. The database allows understanding of material properties and their critical parameters for fusion environments. The system uses J2EE technologies and the PostgreSQL relational database, and flexibility ensures that new methods to automate material design for specific applications can be easily implemented. It runs on a web server and allows users access via the Internet using their preferred web browser. The database allows users to store, browse and search raw tests, material properties and qualified data, and electronic reports. For data security, users are issued with individual accounts, and the origin of all requests is checked against a list of trusted sites. Different user accounts have access to different datasets to ensure the data is not shared unintentionally. The system allows several levels of data checking/cleaning and validation. Data insertion is either online or through downloaded templates, and validation is through different expert groups, which can apply different criteria to the data

  5. Porous biomorphic silicon carbide ceramics coated with hydroxyapatite as prospective materials for bone implants.

    Science.gov (United States)

    Gryshkov, Oleksandr; Klyui, Nickolai I; Temchenko, Volodymyr P; Kyselov, Vitalii S; Chatterjee, Anamika; Belyaev, Alexander E; Lauterboeck, Lothar; Iarmolenko, Dmytro; Glasmacher, Birgit

    2016-11-01

    Porous and cytocompatible silicon carbide (SiC) ceramics derived from wood precursors and coated with bioactive hydroxyapatite (HA) and HA-zirconium dioxide (HA/ZrO2) composite are materials with promising application in engineering of bone implants due to their excellent mechanical and structural properties. Biomorphic SiC ceramics have been synthesized from wood (Hornbeam, Sapele, Tilia and Pear) using a forced impregnation method. The SiC ceramics have been coated with bioactive HA and HA/ZrO2 using effective gas detonation deposition approach (GDD). The surface morphology and cytotoxicity of SiC ceramics as well as phase composition and crystallinity of deposited coatings were analyzed. It has been shown that the porosity and pore size of SiC ceramics depend on initial wood source. The XRD and FTIR studies revealed the preservation of crystal structure and phase composition of in the HA coating, while addition of ZrO2 to the initial HA powder resulted in significant decomposition of the final HA/ZrO2 coating and formation of other calcium phosphate phases. In turn, NIH 3T3 cells cultured in medium exposed to coated and uncoated SiC ceramics showed high re-cultivation efficiency as well as metabolic activity. The recultivation efficiency of cells was the highest for HA-coated ceramics, whereas HA/ZrO2 coating improved the recultivation efficiency of cells as compared to uncoated SiC ceramics. The GDD method allowed generating homogeneous HA coatings with no change in calcium to phosphorus ratio. In summary, porous and cytocompatible bio-SiC ceramics with bioactive coatings show a great promise in construction of light, robust, inexpensive and patient-specific bone implants for clinical application. PMID:27524006

  6. Optical properties of photochromic and thermochromic materials

    Science.gov (United States)

    Mo, Yeon-Gon

    The optical properties of some thin film materials can be altered by an external stimulus. Photochromic and thermochromic materials, including inorganic and organic substances, have optical properties that can be changed in a reversible manner by irradiation and temperature respectively. These materials can be used in applications such as radiation or thermal sensors, information storage devices and smart window applications in buildings and cars. In this work, major effort was concentrated on passive thermal control coatings based on photochromic and thermochromic materials. The inorganic photochromic materials were based on tungsten and molybdenum oxide films and the organic photochromic materials included spiropyrans and spirooxazines. In addition, photochromic composite organic-inorganic films and thermochromic vanadium oxide films were prepared. The samples were synthesized using sputtering, sol-gel process, and thermal oxidation. The optical properties were investigated for the first time by ultraviolet/visible/infrared (UV/VIS/IR) spectroscopic ellipsometry, attenuated total reflection (ATR) infrared ellipsometry, spectrophotometry, and X-ray diffraction (XRD). For amorphous oxide films, the oxygen deficiency was important in determining the photochromic properties of the films. In the mid-infrared region, no photochromism was observed for the films. The optical properties of organic-inorganic composite films changed in the VIS/NIR wavelength region markedly in a reversible process, with UV irradiation. The composite films containing tungsten heteropolyoxometalate (HPOM) showed faster coloration and bleaching than pure tungsten oxide films. The composite films with molybdenum HPOM showed faster coloration and much slower bleaching than tungsten HPOM. The spiropyran and spirooxazine doped polymeric films were investigated for the first time using infrared and ATR ellipsometry. The infrared optical functions obtained by ATR measurements were a little smaller

  7. Modelling electrical properties of composite materials

    OpenAIRE

    Mårtensson, Eva

    2003-01-01

    Composite field grading materials are used to avoid stressconcentrations in high voltage applications such as cableaccessories and generator or motor end windings. The compositematerials consist of an insulating matrix filled with suitableconducting or semi-conducting particles. Silicon carbide (SiC)powder is one such filler that is being employed. The compositematerials display complex electrical characteristics that aredependent on filler properties, particle concentration,frequency and ele...

  8. Irreversibility of electrical insulating material properties

    OpenAIRE

    Radek Polansky; Vaclav Mentlik

    2007-01-01

    Property changes in electrical insulating materials that appear during repeated voltage stress (e. g. in an applied voltage test) are an often discussed problem. The voltage exposure leads to irreversible changes in a negative sense as this investigation clearly demonstrates. A slow deterioration appears even in the case of the above mentioned applied voltage test when the irreversible effects of particular measurements superimpose. These are the effects of irreversible behavior of the insula...

  9. A bioceramic with enhanced osteogenic properties to regulate the function of osteoblastic and osteocalastic cells for bone tissue regeneration.

    Science.gov (United States)

    Roohani-Esfahani, Seyed-Iman; No, Young Jung; Lu, Zufu; Ng, Pei Ying; Chen, Yongjuan; Shi, Jeffrey; Pavlos, Nathan J; Zreiqat, Hala

    2016-01-01

    Bioceramics for regenerative medicine applications should have the ability to promote adhesion, proliferation and differentiation of osteoblast and osteoclast cells. Osteogenic properties of the material are essential for rapid bone regeneration and new bone formation. The aim of this study was to develop a silicate-based ceramic, gehlenite (GLN, Ca2Al2SiO7), and characterise its physiochemical, biocompatibility and osteogenic properties. A pure GLN powder was synthesised by a facile reactive sintering method and compacted to disc-shaped specimens. The sintering behaviour and degradation of the GLN discs in various buffer solutions were fully characterised. The cytotoxicity of GLN was evaluated by direct and indirect methods. In the indirect method, primary human osteoblast cells (HOBs) were exposed to diluted extracts (100, 50, 25, 12.5 and 6.25 mg ml(-1)) of fine GLN particles in culture medium. The results showed that the extracts did not cause any cytotoxic effect on the HOBs with the number of cells increasing significantly from day 1 to day 7. GLN-supported HOB attachment and proliferation, and significantly enhanced osteogenic gene expression levels (Runx2, osteocalcin, osteopontin and bone sialoprotein) were compared with biphasic calcium phosphate groups (BCP, a mixture of hydroxyapatite (60wt.%) and β-tricalcium phosphate(40wt.%)). We also demonstrated that in addition to supporting HOB attachment and proliferation, GLN promoted the formation of tartrate-acid resistance phosphatase (TRAP) positive multinucleated osteoclastic cells (OCs) derived from mouse bone marrow cells. Results also demonstrated the ability of GLN to support the polarisation of OCs, a prerequisite for their functional resorptive activity which is mainly influenced by the composition and degradability of biomaterials. Overall, the developed GLN is a prospective candidate to be used in bone regeneration applications due its effective osteogenic properties and biocompatibility. PMID

  10. An automatic approach for calibrating dielectric bone properties by combining finite-element and optimization software tools.

    Science.gov (United States)

    Su, Yukun; Kluess, Daniel; Mittelmeier, Wolfram; van Rienen, Ursula; Bader, Rainer

    2016-09-01

    The dielectric properties of human bone are one of the most essential inputs required by electromagnetic stimulation for improved bone regeneration. Measuring the electric properties of bone is a difficult task because of the complexity of the bone structure. Therefore, an automatic approach is presented to calibrate the electric properties of bone. The numerical method consists of three steps: generating input from experimental data, performing the numerical simulation, and calibrating the bone dielectric properties. As an example, the dielectric properties at 20 Hz of a rabbit distal femur were calibrated. The calibration process was considered as an optimization process with the aim of finding the optimum dielectric bone properties that match most of the numerically calculated simulation and experimentally measured data sets. The optimization was carried out automatically by the optimization software tool iSIGHT in combination with the finite-element solver COMSOL Multiphysics. As a result, the optimum conductivity and relative permittivity of the rabbit distal femur at 20 Hz were found to be 0.09615 S/m and 19522 for cortical bone and 0.14913 S/m and 1561507 for cancellous bone, respectively. The proposed method is a potential tool for the identification of realistic dielectric properties of the entire bone volume. The presented approach combining iSIGHT with COMSOL is applicable to, amongst others, designing implantable electro-stimulative devices or the optimization of electrical stimulation parameters for improved bone regeneration. PMID:26777343

  11. Bone properties of the humeral head and resistance to screw cutout

    DEFF Research Database (Denmark)

    Frich, L. H.; Jensen, N. C.

    2014-01-01

    Surgical treatment of fractures involving the proximal humeral head is hampered by complications. Screw cutout is the major pitfall seen in connection with rigid plating. We have exploited a bony explanation for this phenomenon. Materials and Methods: We examined the convex surface of the humeral...... anisotropy was also found. We found in particular a lower bone strength and density in the posterior and inferior regions of the humeral head. A rapid decline in bone strength within a few mm below a relatively thin subchondral plate was also reported. Clinical Relevance: We have in this paper explored some...... of the most important factors connected with screw stability at the cancellous bone level. We discovered large variations in bone density and bone strength across the joint surface rendering certain areas of the humeral head less suitable for screw placement. The use of rigid plate constructs with...

  12. Properties of nanoclay PVA composites materials

    Directory of Open Access Journals (Sweden)

    Mohamed H. M. Ali

    2012-03-01

    Full Text Available Polyvinyl alcohol (PVA/ Na-rich Montmorillonite (MMT nanocomposites were prepared using solution method to create polymer-clay nanocomposite (PCN material. The PCN material was studied using X-ray diffraction (XRD, demonstrating polymer-clay intercalation that has a high d-spacing (lower diffraction angles in the PCN XRD pattern, compared to the pure MMT clay XRD pattern, which has a low d-spacing (high diffraction angles. The nano-scanning electron microscope (NSEM was used to study the morphological image of the PVA, MMT and PCN materials. The results showed that intercalation that took place between the PVA and MMT produced the PCN material. The mechanical properties of the pure PVA and the intercalated polymer material were studied. It was found that the small amount of MMT clay made the tensile modulus and percentage of the total elongation of the nano-composite significantly higher than the pure PVA polymer value, due to polymer-clay intercalation. The thermal stability of the intercalated polymer has been studied using thermal analytical techniques such as thermogravimetric analysis (TGA and differential scanning calorimetry (DSC. The results showed that the PCN material is more thermally stable than the pure PVA polymer.

  13. The effects of hibernation and forced disuse (neurectomy) on bone properties in arctic ground squirrels.

    Science.gov (United States)

    Bogren, Lori K; Johnston, Erin L; Barati, Zeinab; Martin, Paula A; Wojda, Samantha J; Van Tets, Ian G; LeBlanc, Adrian D; Donahue, Seth W; Drew, Kelly L

    2016-05-01

    Bone loss is a well-known medical consequence of disuse such as in long-term space flight. Immobilization in many animals mimics the effects of space flight on bone mineral density. Decreases in metabolism are also thought to contribute to a loss of skeletal mass. Hibernating mammals provide a natural model of disuse and metabolic suppression. Hibernating ground squirrels have been shown to maintain bone strength despite long periods of disuse and decreased metabolism during torpor. This study examined if the lack of bone loss during torpor was a result of the decrease in metabolic rate during torpor or an evolutionary change in these animals affording protection against disuse. We delineated changes in bone density during natural disuse (torpor) and forced disuse (sciatic neurectomy) in the hind limbs of the arctic ground squirrel (AGS) over an entire year. We hypothesized that the animals would be resistant to bone loss due to immobilization and disuse during the winter hibernation season when metabolism is depressed but not the summer active season. This hypothesis was not supported. The animals maintained bone density (dual-energy X-ray absorptiometry) and most bone structural and mechanical properties in both seasons. This was observed in both natural and forced disuse, regardless of the known metabolic rate increase during the summer. However, trabecular bone volume fraction (microcomputed tomography) in the distal femur was lower in neurectomized AGS at the study endpoint. These results demonstrate a need to better understand the relationship between skeletal load (use) and bone density that may lead to therapeutics or strategies to maintain bone density in disuse conditions. PMID:27225624

  14. Modelling of the dielectric properties of trabecular bone samples at microwave frequency

    CERN Document Server

    Irastorza, Ramiro M; Carlevaro, Carlos M; Vericat, Fernando

    2013-01-01

    In this paper the dielectric properties of human trabecular bone are evaluated under physiological condition in the microwave range. Assuming a two components medium, simulation and experimental data are presented and discussed. A special experimental setup is developed in order to deal with inhomogeneous samples. Simulation data are obtained using finite difference time domain from a realistic sample. The bone mineral density of the samples are also measured. The simulation and experimental results of the present study suggest that there is a negative relation between bone volume fraction (BV/TV) and permittivity (conductivity): the higher the BV/TV the lower the permittivity (conductivity). This is in agreement with the recently published in vivo data. Keywords: Bone dielectric properties, Microwave tomography, Finite difference time domain.

  15. Bone density does not reflect mechanical properties in early-stage arthrosis

    DEFF Research Database (Denmark)

    Ding, Ming; Danielsen, CC; Hvid, I

    2001-01-01

    Subchondral cancellous bone specimens were removed from 10 human postmortem early-stage arthrotic proximal tibiae (mean age 73 (63-81) years) and 10 age- and gender-matched normal proximal tibiae. The early-stage arthrosis was confirmed histologically and the specimens were divided into 4 groups......: medial arthrosis, lateral control, normal medial and normal lateral controls. The specimens were tested in compression to determine mechanical properties and then physical/compositional properties. Compared to the normal medial control, we found reductions in ultimate stress, Young's modulus, and failure...... energy, and an increase in ultimate strain of arthrotic cancellous bone. Bone volume fraction, apparent density, apparent ash density, and collagen density were higher in cancellous bone with arthrosis, but no differences were found in tissue density, mineral and collagen concentrations between arthrotic...

  16. Electron beam irradiation to the allogeneic, xenogenic and synthetic bone materials

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Soung Min; Park, Min Woo; Jeong, Hyun Oh [School of Dentistry Seoul National University, Seoul (Korea, Republic of); and others

    2013-07-01

    For the development of the biocompatible bony regeneration materials, allogenic, xenogenic and synthetic bone were irradiated by electron beam to change the basic components and structures. For the efficient electron beam irradiating condition of these allogenic, xenogenic and artificial bone substitutes, the optimal electron beam energy and their individual dose were established, to maximize the bony regeneration capacity. Commercial products of four allogenic bones, such as Accell (ISOTIS OrthogBiologics Co., USA), Allotis (Korea Bone Bank Co., Korea), Oragraft (LifeNet Co., USA), and Orthoblast (Integra Orthobiologics Inc., USA), six xenogenic bones, such as BBP (OscoTec Co., Korea), Bio-cera (OscoTec Co., Korea), Bio-oss (Geistlich Pharma AG, Switzerland), Indu-cera (OscoTec Co., Korea), OCS-B (Nibec Co., Korea), and OCS-H (Nibec Co., Korea), and six synthetic bones, such as BMP (Couellmedi Co., Korea), BoneMedik (Meta Biomed Co., Korea), Bone plus (Megagen Co., Korea), MBCP (Biomatlante Co., France), Osteon (Genoss Co., Korea), and Osteogen (Impladent LTD., USA), were used. We used 1.0 and 2.0 MeV superconduction accelerator, and/or microtrone with different individual 60, 120 kGy irradiation dose. Different dose irradiated specimens were divided 6 portions each, so total 360 groups were prepared. 4 portions were analyzed each by elementary analysis using FE-SEM (Field Emission Scanning Microscopy) and another 2 portions were grafted to the calvarial defect of Sprague-Dawley rat, following histologic, immunohistochemical analysis and TEM study were processed at the 8th and 16th weeks, in vivo. This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MEST)

  17. Bioactive hydrogel-nanosilica hybrid materials: a potential injectable scaffold for bone tissue engineering

    International Nuclear Information System (INIS)

    Novel bioactive organic–inorganic hybrid materials that can serve as injectable hydrogel systems for bone tissue regeneration were obtained. The silica nanoparticles (SiNP) prepared in situ by the Stöber method were dispersed in collagen, collagen-chitosan or chitosan sols, which were then subsequently crosslinked. Laser scanning confocal microscopy studies, in which fluorescent SiNP were applied, and SEM images indicated that the nanosilica particles were distributed in the whole volume of the hydrogel matrix. In vitro studies on fibroblast cell viability indicated that the hybrid materials are biocompatible. The silica nanoparticles dispersed in the biopolymer matrix had a positive effect on cell viability. Studies on the mineralization process under simulated body fluid (SBF) conditions confirmed the bioactivity of prepared materials. SEM images revealed mineral phase formation in the majority of the hybrid materials developed. EDS analysis indicated that these mineral phases are mainly composed of calcium and phosphorus. The XRD studies confirmed that mineral phases formed during SBF incubation of hybrid materials based on collagen are bone-like apatite minerals. The silica nanoparticles added to the hydrogel at the stage of synthesis induced the occurrence of mineralization. This process occurs not only at the surface of the material but in its entire volume, which is important for the preparation of scaffolds for bone tissue engineering. The ability of these materials to undergo in situ gelation under physiological temperature and their bioactivity as well as biocompatibility make them interesting candidates for bioactive injectable systems. (paper)

  18. Correction: Mechanical properties of femoral trabecular bone in dogs

    OpenAIRE

    Behrens Bernd-Arno; Meyer-Lindenberg Andrea; Vogt Ute; Bouguecha Anas; Pressel Thomas; Nolte Ingo; Windhagen Henning

    2005-01-01

    Abstract After the publication of this work 1, we became aware of the fact that the frequency of the ultrasound transmitter that we used for determining the elastic moduli of the trabecular bone specimens was not correctly specified. The oscillation frequency of the ultrasound transmitter was 2 MHz (and not 100 MHz as stated in our work) while we used a sampling rate of 100 MHz. In our publication, the oscillation frequency and sampling rate were confounded. Therefore also the statement in th...

  19. Fresh-frozen bone: case series of a new grafting material for sinus lift and immediate implants.

    LENUS (Irish Health Repository)

    Viscioni, A

    2010-08-01

    Although autologous bone is considered to be the gold standard grafting material, it needs to be harvested from patients, a process that can be off-putting and can lead to donor site morbidity. For this reason, homologous fresh-frozen bone (FFB) was used in the current study as an alternative graft material.

  20. Evolution of bone biomechanical properties at the micrometer scale around titanium implant as a function of healing time

    International Nuclear Information System (INIS)

    The characterization of the biomechanical properties of newly formed bone tissue around implants is important to understand the osseointegration process. The objective of this study is to investigate the evolution of elastic properties of newly formed bone tissue as a function of healing time. To do so, nanoindentation and micro-Brillouin scattering techniques are coupled following a multimodality approach using histological analysis. Coin-shaped implants were placed in vivo at a distance of 200 µm from the cortical bone surface, leading to an initially empty cavity. Two rabbits were sacrificed after 7 and 13 weeks of healing time. The histological analyses allow us to distinguish mature and newly formed bone tissue. The bone mechanical properties were measured in mature and newly formed bone tissue. Analysis of variance and Tukey–Kramer tests reveals a significant effect of healing time on the indentation modulus and ultrasonic velocities of bone tissue. The results show that bone mass density increases by 12.2% (2.2% respectively) between newly formed bone at 7 weeks (13 weeks respectively) and mature bone. The dependence of bone properties on healing time may be explained by the evolution of bone microstructure and mineralization. (paper)

  1. Evolution of bone biomechanical properties at the micrometer scale around titanium implant as a function of healing time

    Science.gov (United States)

    Vayron, Romain; Matsukawa, Mami; Tsubota, Ryo; Mathieu, Vincent; Barthel, Etienne; Haiat, Guillaume

    2014-03-01

    The characterization of the biomechanical properties of newly formed bone tissue around implants is important to understand the osseointegration process. The objective of this study is to investigate the evolution of elastic properties of newly formed bone tissue as a function of healing time. To do so, nanoindentation and micro-Brillouin scattering techniques are coupled following a multimodality approach using histological analysis. Coin-shaped implants were placed in vivo at a distance of 200 µm from the cortical bone surface, leading to an initially empty cavity. Two rabbits were sacrificed after 7 and 13 weeks of healing time. The histological analyses allow us to distinguish mature and newly formed bone tissue. The bone mechanical properties were measured in mature and newly formed bone tissue. Analysis of variance and Tukey-Kramer tests reveals a significant effect of healing time on the indentation modulus and ultrasonic velocities of bone tissue. The results show that bone mass density increases by 12.2% (2.2% respectively) between newly formed bone at 7 weeks (13 weeks respectively) and mature bone. The dependence of bone properties on healing time may be explained by the evolution of bone microstructure and mineralization.

  2. Changes in Mechanical Properties of Rat Bones under Simulated Effects of Microgravity and Radiation†

    Science.gov (United States)

    Walker, Azida H.; Perkins, Otis; Mehta, Rahul; Ali, Nawab; Dobretsov, Maxim; Chowdhury, Parimal

    The aim of this study was to determine the changes in elasticity and lattice structure in leg bone of rats which were: 1) under Hind-Limb Suspension (HLS) by tail for 2 weeks and 2) exposed to a total radiation of 10 Grays in 10 days. The animals were sacrificed at the end of 2 weeks and the leg bones were surgically removed, cleaned and fixed with a buffered solution. The mechanical strength of the bone (elastic modulus) was determined from measurement of bending of a bone when under an applied force. Two methodologies were used: i) a 3-point bending technique and ii) classical bending where bending is accomplished keeping one end fixed. Three point bending method used a captive actuator controlled by a programmable IDEA drive. This allowed incremental steps of 0.047 mm for which the force is measured. The data is used to calculate the stress and the strain. In the second method a mirror attached to the free end of the bone allowed a reflected laser beam spot to be tracked. This provided the displacement measurement as stress levels changed. Analysis of stress vs. strain graph together with solution of Euler-Bernoulli equation for a cantilever beam allowed determination of the elastic modulus of the leg bone for (i) control samples, (ii) HLS samples and (iii) HLS samples with radiation effects. To ascertain changes in the bone lattice structure, the bones were cross-sectioned and imaged with a 20 keV beam of electrons in a Scanning Electron Microscope (SEM). A backscattered detector and a secondary electron detector in the SEM provided the images from well-defined parts of the leg bones. Elemental compositions in combination with mechanical properties (elastic modulus and lattice structure) changes indicated weakening of the bones under space-like conditions of microgravity and radiation.

  3. Comparison of sealing ability of bioactive bone cement, mineral trioxide aggregate and Super EBA as furcation repair materials: A dye extraction study

    Directory of Open Access Journals (Sweden)

    Janani Balachandran

    2013-01-01

    Settings and Design: In vitro, dye extraction study. Materials and Methods: Forty mandibular molars were randomly divided according to the material used to repair perforation: Group I-MTA, Group II-bioactive bone cement, Group III-Super EBA, Group IV-Control (furcation left unrepaired. All samples were subject to ortho grade and retrograde methylene blue dye challenge followed by dye extraction with 65% nitric acid. Samples were then analyzed using Ultra violet (UV Visible Spectrophotometer. Statistical Analysis Used: One way analysis of variance (ANOVA, Tukey-Kramer Multiple Comparisons Test. Results: MTA and bioactive bone cement showed almost similar and lower absorbance values in comparison to Super EBA. Conclusions: Bioactive bone cement provi ded an excellent seal for furcal perforation repair and at the same time it provided comfortable handling properties, which could overcome the potential disadvantages as faced with MTA.

  4. Helium retention properties of plasma facing materials

    International Nuclear Information System (INIS)

    In a fusion reactor, the continuous removal of helium from the core plasma is needed in order to sustain the ignition condition. For this purpose, it has been proposed to place helium selective pumping metals, which can trap more helium than hydrogen, in the vicinity of the divertor. In this study, the helium and hydrogen trapping properties of nickel, tungsten, molybdenum, SS 304 and Inconel 625 were examined. Namely, the dependencies of irradiation temperature on the amount of trapped helium and hydrogen were obtained by thermal desorption spectroscopy (TDS), after helium or hydrogen plasma irradiation. In those metals, nickel showed the most suitable selective pumping capability. Nickel had the helium selective pumping property above 100 C. The maximum amount of trapped helium was (2-3) x 1016 He/cm2 at an irradiation temperature of 200 C and 600 C. The optimum temperature becomes about 600 C when nickel is used for a selective pumping material. (orig.)

  5. Characteristics of Materials to Be Used in Bone Surgery

    Czech Academy of Sciences Publication Activity Database

    Sochor, M.; Balík, Karel; Sedláček, R.; Tichý, P.; Suchý, Tomáš

    Praha : České vysoké učení technické, 2002, s. 237-240. ISBN 80-01-02547-0. [EAN - Experimentální analýza napětí 2002. Praha (CZ), 01.01.2002] R&D Projects: GA ČR GA106/00/1407 Institutional research plan: CEZ:AV0Z3046908 Keywords : C-C composite * mechanical testing * biocompatibility Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass

  6. Bioreactor activated graft material for early implant fixation in bone

    DEFF Research Database (Denmark)

    Snoek Henriksen, Susan; Ding, Ming; Overgaard, Søren

    2011-01-01

    from the iliac crest. For both groups, mononuclear cells were isolated, and injected into a perfusion bioreactor (Millenium Biologix AG, Switzerland). Scaffold granules (Ø~900-1500 µm, ~88% porosity) in group 1, consisted of hydroxyapatite (HA, 70%) with β-tricalcium-phosphate (β-TCP, 30%) (Danish...... Technological Institute, Denmark). The granules were coated with poly-lactic acid (PLA) 12%, in order to increase the mechanical strength of the material (Phusis, France). Scaffold granules (Ø~900-1400 µm, 80% porosity) in group 2 consisted of pure HA/β-TCP (FinCeramica, Italy). For both groups, cells were...

  7. Biomineralization of Engineered Spider Silk Protein-Based Composite Materials for Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    John G. Hardy

    2016-07-01

    Full Text Available Materials based on biodegradable polyesters, such as poly(butylene terephthalate (PBT or poly(butylene terephthalate-co-poly(alkylene glycol terephthalate (PBTAT, have potential application as pro-regenerative scaffolds for bone tissue engineering. Herein, the preparation of films composed of PBT or PBTAT and an engineered spider silk protein, (eADF4(C16, that displays multiple carboxylic acid moieties capable of binding calcium ions and facilitating their biomineralization with calcium carbonate or calcium phosphate is reported. Human mesenchymal stem cells cultured on films mineralized with calcium phosphate show enhanced levels of alkaline phosphatase activity suggesting that such composites have potential use for bone tissue engineering.

  8. Synchrotron X-ray bio-imaging of natural and synthetic bone-graft materials in an aqueous environment

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong-Gun [Kyungpook National University, Daegu (Korea, Republic of); Bark, Chung-Wung [Gachon University, Seongnam (Korea, Republic of)

    2014-11-15

    Bone-graft materials in dentistry have osteoinductive and osteoconductive abilities, which depend on their microstructural characteristics, such as their porosity, particle size, micro channels, and absorption. These characteristics have been observed using various imaging techniques, such as optical microscopy and scanning electron microscopy (SEM). However, most techniques cannot provide images in water, even though graft materials in vivo are invariably in contact with different water-based fluids. Synchrotron X-ray imaging allows sample micro environments to be controlled as X-ray beams easily penetrate air and water. In this report, we used the synchrotron X-ray imaging technique to provide in-situ images of various bone-graft materials in aqueous environments. We observed internal microstructural images of bone-graft materials in real-time in 0.9% saline solution and interactions between bone-graft materials and saline, that is, hydration patterns and bone-graft expansion.

  9. Synchrotron X-ray bio-imaging of natural and synthetic bone-graft materials in an aqueous environment

    International Nuclear Information System (INIS)

    Bone-graft materials in dentistry have osteoinductive and osteoconductive abilities, which depend on their microstructural characteristics, such as their porosity, particle size, micro channels, and absorption. These characteristics have been observed using various imaging techniques, such as optical microscopy and scanning electron microscopy (SEM). However, most techniques cannot provide images in water, even though graft materials in vivo are invariably in contact with different water-based fluids. Synchrotron X-ray imaging allows sample micro environments to be controlled as X-ray beams easily penetrate air and water. In this report, we used the synchrotron X-ray imaging technique to provide in-situ images of various bone-graft materials in aqueous environments. We observed internal microstructural images of bone-graft materials in real-time in 0.9% saline solution and interactions between bone-graft materials and saline, that is, hydration patterns and bone-graft expansion.

  10. Cement replacement materials. Properties, durability, sustainability

    Energy Technology Data Exchange (ETDEWEB)

    Ramezanianpour, Ali Akbar [Amirkabir Univ. of Technology, Tehran (Iran, Islamic Republic of). Concrete Technology Center

    2014-04-01

    The aim of this book is to present the latest findings in the properties and application of Supplementary Cementing Materials and blended cements currently used in the world in concrete. Sustainability is an important issue all over the world. Carbon dioxide emission has been a serious problem in the world due to the greenhouse effect. Today many countries agreed to reduce the emission of CO2. Many phases of cement and concrete technology can affect sustainability. Cement and concrete industry is responsible for the production of 7% carbon dioxide of the total world CO2 emission. The use of supplementary cementing materials (SCM), design of concrete mixtures with optimum content of cement and enhancement of concrete durability are the main issues towards sustainability in concrete industry.

  11. New Monolayered Materials Exhibiting Unusual Electronic Properties

    Science.gov (United States)

    Lopez-Bezanilla, Alejandro; Martin, Ivar; Littlewood, Peter B.

    Computationally based approaches are allowing to progress in the discovery and design of nano-scaled materials. Here we propose a series of new mono-layered compounds with exotic properties. By means of density functional theory calculations we demonstrate that the pentagonal arrangement of SiC2 yields an inverted distribution of the p-bands which leads to an unusual electronic behaviour of the material under strain [J. Phys. Chem. C, 2015, 119 (33), pp 19469]. A different pentagonal arrangement of C atoms enables the formation of Dirac cones which, unlike graphene, exhibit a strain-mediated tunable band gap. This work is supported by DOE-BES under Contract No. DE-AC02-06CH11357.

  12. Thermal Radiative Properties of Xonotlite Insulation Material

    Institute of Scientific and Technical Information of China (English)

    Xinxin ZHANG; Gaosheng WEI; Fan YU

    2005-01-01

    This paper presents experimental results of thermal radiative properties of xonotlite-type calcium silicate insulation material. Transmittance spectra were first taken using Fourier transform infrared spectrometer (FTIR)for the samples with ρ = 234 kg/m3. Specific extinction coefficient spectra were then obtained by applying Beer's law.Finally,by using the diffusion approximation,the specific Rossland mean extinction coefficients and radiative thermal conductivities were obtained for various temperatures. The results show that the specific spectral extinction coefficient of xonotlite is larger than 7 m2/kg in the whole measured spectra, and diffusion approximation equation is a reasonable description of radiative heat transfer in xonotlite insulation material. The specific Rossland mean extinction coefficient of xonotlite has a maximum ualue at 400 K and the radiative thermal conductivity is almost proportional to the cube of temperature.

  13. Basic radiation sterilization properties of packaging materials

    International Nuclear Information System (INIS)

    The foils of various materials were irradiated with 60Co with an activity of 11,538 TBq. The minimum radiation dose was 25 kGy. Changes in chemico-physical properties were evaluated by infrared spectroscopy and were not detected after irradiation with 25 kGy. Packing foils were subjected to the following tests: mechanical tests, tests of weld strength, tests of impact resistance, free fall tests, permeability tests for water vapour and microbiological tests. The results of all tests were tabulated. The tests showed that the foils are impermeable for microorganisms and provided the welds are airtight the packed products remain sterile. (J.P.)

  14. A novel open-porous magnesium scaffold with controllable microstructures and properties for bone regeneration

    Science.gov (United States)

    Cheng, Meng-Qi; Wahafu, Tuerhongjiang; Jiang, Guo-Feng; Liu, Wei; Qiao, Yu-Qin; Peng, Xiao-Chun; Cheng, Tao; Zhang, Xian-Long; He, Guo; Liu, Xuan-Yong

    2016-04-01

    The traditional production methods of porous magnesium scaffolds are difficult to accurately control the pore morphologies and simultaneously obtain appropriate mechanical properties. In this work, two open-porous magnesium scaffolds with different pore size but in the nearly same porosity are successfully fabricated with high-purity Mg ingots through the titanium wire space holder (TWSH) method. The porosity and pore size can be easily, precisely and individually controlled, as well as the mechanical properties also can be regulated to be within the range of human cancellous bone by changing the orientation of pores without sacrifice the requisite porous structures. In vitro cell tests indicate that the scaffolds have good cytocompatibility and osteoblastic differentiation properties. In vivo findings demonstrate that both scaffolds exhibit acceptable inflammatory responses and can be almost fully degraded and replaced by newly formed bone. More importantly, under the same porosity, the scaffolds with larger pore size can promote early vascularization and up-regulate collagen type 1 and OPN expression, leading to higher bone mass and more mature bone formation. In conclusion, a new method is introduced to develop an open-porous magnesium scaffold with controllable microstructures and mechanical properties, which has great potential clinical application for bone reconstruction in the future.

  15. Materials with complex behaviour II properties, non-classical materials and new technologies

    CERN Document Server

    Oechsner, Andreas

    2012-01-01

    This book reviews developments and trends in advanced materials and their properties; modeling and simulation of non-classical materials and new technologies for joining materials. Offers tools for characterizing and predicting properties and behavior.

  16. In vivo microindentation for the assessment of bone material properties

    OpenAIRE

    Güerri Fernández, Robert

    2013-01-01

    El objetivo principal de esta tesis es el estudio de la aplicación de microindentación del hueso en la clínica. El uso de la densidad mineral ósea para evaluar la calidad ósea no es suficiente. De hecho, hay pacientes con densidad mineral ósea normal o casi normal que presentan fracturas. Se ha publicado que la capacidad predictiva de la densidad mineral ósea para el riesgo de fractura oscila entre el 65-70%. Esto podría explicarse por el hecho de que con la densidad mineral ósea estamos...

  17. Tooth Movement out of the Bony Wall Using Augmented Corticotomy with Nonautogenous Graft Materials for Bone Regeneration

    Directory of Open Access Journals (Sweden)

    Kye-Bok Lee

    2014-01-01

    Full Text Available This prospective randomized split-mouth study was performed to compare the effects of augmented corticotomy with those of different nonautogenous bone graft materials combined with orthodontic tooth movement in dogs. Decortication was performed on the buccal bone surface of 6 male beagle dogs that were randomly assigned to receive grafts of deproteinized bovine bone mineral, irradiated cortical bone, or synthetic bone. Immediate orthodontic force was applied to the second and third premolars for buccal tipping for 6 weeks. The pocket depth and width of keratinized tissue (WKT were measured. Histologic and histomorphometric analyses were performed. The probing depth, WKT, and ratio of the area of new bone to that of total bone on the buccal side were not significantly different between groups. All groups had considerable new bone formation on the pressure side. New bone formation on the buccal side and buccal plate formation in the coronal direction along the root surfaces were induced by the bone-derived and PDL-derived mesenchymal matrix, respectively. The angular change between groups was significantly different (P < 0.001. Augmented corticotomy using nonautogenous graft materials facilitated tooth movement without fenestrations and accelerated new bone formation on the pressure side.

  18. Tooth movement out of the bony wall using augmented corticotomy with nonautogenous graft materials for bone regeneration.

    Science.gov (United States)

    Lee, Kye-Bok; Lee, Dong-Yeol; Ahn, Hyo-Won; Kim, Seong-Hun; Kim, Eun-Cheol; Roitman, Igor

    2014-01-01

    This prospective randomized split-mouth study was performed to compare the effects of augmented corticotomy with those of different nonautogenous bone graft materials combined with orthodontic tooth movement in dogs. Decortication was performed on the buccal bone surface of 6 male beagle dogs that were randomly assigned to receive grafts of deproteinized bovine bone mineral, irradiated cortical bone, or synthetic bone. Immediate orthodontic force was applied to the second and third premolars for buccal tipping for 6 weeks. The pocket depth and width of keratinized tissue (WKT) were measured. Histologic and histomorphometric analyses were performed. The probing depth, WKT, and ratio of the area of new bone to that of total bone on the buccal side were not significantly different between groups. All groups had considerable new bone formation on the pressure side. New bone formation on the buccal side and buccal plate formation in the coronal direction along the root surfaces were induced by the bone-derived and PDL-derived mesenchymal matrix, respectively. The angular change between groups was significantly different (P corticotomy using nonautogenous graft materials facilitated tooth movement without fenestrations and accelerated new bone formation on the pressure side. PMID:25247172

  19. Physical and chemical properties of fish and chicken bones as calcium source for mineral supplements

    Directory of Open Access Journals (Sweden)

    Worapot Suntornsuk

    2006-03-01

    Full Text Available Physical and chemical properties of two bones of two species of fish, hoki (Macruronus novaezelandiae and giant seaperch (Lates calcarifer Bloch., were compared with chicken bone to evaluate their composition for use as natural calcium supplement. The information could be useful for waste utilization in the food and pharmaceutical industries. Physical testing and chemical analyses were performed according to the USP 24 and BP 1998 standards under calcium carbonate monograph. Loss on drying found in hoki, giant seaperch and chicken bones was 12.4, 11.3 and 5.9 % w/w, calculated on dried basis, respectively. Total calcium determined by complexometric titration was 31.8, 28.1 and 32.2% w/w in hoki, giant seaperch and chicken bones, respectively. All samples contained carbonate and phosphate anion residues but gluconate, acetate and citrate were absent. The presence of calcium carbonate was confirmed by thermogravimetry. Results from all bones showed that limit tests for heavy metals, arsenic and iron complied with the USP standard, whereas barium, chloride and sulfate conformed to the BP standard. The magnesium and alkali metals in giant seaperch bone were within the BP limit (1.5%, but those of hoki and chicken bone exceeded the limit.

  20. New antibacterial microporous CaP materials loaded with phages for prophylactic treatment in bone surgery.

    Science.gov (United States)

    Meurice, Edwige; Rguiti, Emmanuelle; Brutel, Annie; Hornez, Jean-Christophe; Leriche, Anne; Descamps, Michel; Bouchart, Franck

    2012-10-01

    Hydroxyapatite and beta-tricalcium phosphate (β-TCP) are materials commonly used in bone repair. The most important problem occurring in bone repair surgery is bacterial infection which is usually overcome by treatment with antibiotics. Currently, emergence of multidrug resistant strains has led to development of alternative treatments such as phage therapy. Phages are bacterial viruses with several advantages over chemotherapy such as specificity of bacterial strain, no side effects and fast response. This study evaluates the possibility of loading hydroxyapatite and β-tricalcium phosphate ceramics used as bone substitutes with phages and their antibacterial activity against Escherichia coli K12. The majority of phages were retained in dense and microporous HA and β-TCP samples during at least 6 days suggesting the occurrence of strong interaction between phages and ceramics, which did not prevent bacterial attachment and lysis. This study has shown for the first time that phage loaded ceramics could be used in prophylactic treatments. PMID:22802104

  1. International nuclear safety center database on material properties

    International Nuclear Information System (INIS)

    International nuclear safety center database on the following material properties is described: fuel, cladding,absorbers, moderators, structural materials, coolants, concretes, liquid mixtures, uranium dioxide

  2. Porous surface modified bioactive bone cement for enhanced bone bonding.

    Directory of Open Access Journals (Sweden)

    Qiang He

    Full Text Available BACKGROUND: Polymethylmethacrylate bone cement cannot provide an adhesive chemical bonding to form a stable cement-bone interface. Bioactive bone cements show bone bonding ability, but their clinical application is limited because bone resorption is observed after implantation. Porous polymethylmethacrylate can be achieved with the addition of carboxymethylcellulose, alginate and gelatin microparticles to promote bone ingrowth, but the mechanical properties are too low to be used in orthopedic applications. Bone ingrowth into cement could decrease the possibility of bone resorption and promote the formation of a stable interface. However, scarce literature is reported on bioactive bone cements that allow bone ingrowth. In this paper, we reported a porous surface modified bioactive bone cement with desired mechanical properties, which could allow for bone ingrowth. MATERIALS AND METHODS: The porous surface modified bioactive bone cement was evaluated to determine its handling characteristics, mechanical properties and behavior in a simulated body fluid. The in vitro cellular responses of the samples were also investigated in terms of cell attachment, proliferation, and osteoblastic differentiation. Furthermore, bone ingrowth was examined in a rabbit femoral condyle defect model by using micro-CT imaging and histological analysis. The strength of the implant-bone interface was also investigated by push-out tests. RESULTS: The modified bone cement with a low content of bioactive fillers resulted in proper handling characteristics and adequate mechanical properties, but slightly affected its bioactivity. Moreover, the degree of attachment, proliferation and osteogenic differentiation of preosteoblast cells was also increased. The results of the push-out test revealed that higher interfacial bonding strength was achieved with the modified bone cement because of the formation of the apatite layer and the osseointegration after implantation in the bony

  3. [Effect of dosed diet restriction on physiological remodeling and bioelectric properties of bone].

    Science.gov (United States)

    Levashov, M I; Ianko, R V; Chaka, E G; Safonov, S L

    2014-07-01

    The effect of dosed diet restriction on the physiological remodeling and bioelectric properties of bone tissue was studied in 48 male Wistar rats 3- and 18-months of age. The rate of bone tissue apposition was studied by the dynamic histomorphometry method (intravital tetracycline labeling). Electric potentials on the periosteal surface of the freshly isolated femurs were recorded. The magnitude of dielectric loss factor was determined to assess the quality of bone tissue. The control rats received a standard diet. The experimental rats received a limited diet (60 % of the standard mass) for 28 days. The magnitude and rate of the bone tissue apposition on the endosteal and periosteal surface of the tibia were less by 38.4% and 122.7% respectively in experimental rats after dosed diet restriction. Electric potential in the metaphyseal-epiphyseal growth zones of the femur was 29.7% lower, and the dielectric loss factor increased by 15.8%. The bone tissue apposition rate and the electric potential magnitude were increased 10 days after completion of the dosed diet restriction. The magnitude of the dielectric loss factor decreased after returning to the standard diet. Key words: dosed diet restriction, bone, remodelling, bioelectric properties. PMID:25669112

  4. Hydroxyapatite from fish scale for potential use as bone scaffold or regenerative material.

    Science.gov (United States)

    Pon-On, Weeraphat; Suntornsaratoon, Panan; Charoenphandhu, Narattaphol; Thongbunchoo, Jirawan; Krishnamra, Nateetip; Tang, I Ming

    2016-05-01

    The present paper studies the physico-chemical, bioactivity and biological properties of hydroxyapatite (HA) which is derived from fish scale (FS) (FSHA) and compares them with those of synthesized HA (sHA) obtained by co-precipitation from chemical solution as a standard. The analysis shows that the FSHA is composed of flat-plate nanocrystal with a narrow width size of about 15-20nm and having a range of 100nm in length and that the calcium phosphate ratio (Ca/P) is 2.01 (Ca-rich CaP). Whereas, synthesized HA consists of sub-micron HA particle having a Ca/P ratio of 1.65. Bioactivity test shows that the FSHA forms more new apatite than does the sHA after being incubated in simulated body fluid (SBF) for 7days. Moreover, the biocompatibility study shows a higher osteoblast like cell adhesion on the FSHA surface than on the sHA substrate after 3days of culturing. Our results also show the shape of the osteoblast cells on the FSHA changes from being a rounded shape to being a flattened shape reflecting its spreading behavior on this surface. MTT assay and ALP analysis show significant increases in the proliferation and activity of osteoblasts over the FSHA scaffold after 5days of culturing as compared to those covering the sHA substrates. These results confirm that the bio-materials derived from fish scale (FSHA) are biologically better than the chemically synthesized HA and have the potential for use as a bone scaffold or as regenerative materials. PMID:26952413

  5. Mechanical and structural properties of bone in non-critical and critical healing in rat.

    Science.gov (United States)

    Hoerth, Rebecca M; Seidt, Britta M; Shah, Miheer; Schwarz, Carolin; Willie, Bettina M; Duda, Georg N; Fratzl, Peter; Wagermaier, Wolfgang

    2014-09-01

    A fracture in bone results in a dramatic change of mechanical loading conditions at the site of injury. Usually, bone injuries heal normally but with increasing fracture gaps, healing is retarded, eventually leading to non-unions. The clinical situation of these two processes with different outcomes is well described. However, the exact relation between the mechanical environment and characteristics of the tissues at all levels of structural hierarchy remains unclear. Here we studied the differences in material formation of non-critical (1mm) and critical (5mm gap) healing. We employed a rat osteotomy model to explore bone material structure depending upon the different mechanical conditions. In both cases, primary bone formation was followed by secondary bone deposition with mineral particle sizes changing from on average short and thick to long and thin particles. Bony bridging occurred at first in the endosteal callus and the nanostructure and microstructure developed towards cortical ordered material organization. In contrast, in critical healing, instead of bridging, a marrow cavity closure was formed endosteal, exhibiting tissue structure oriented along the curvature and a periosteal callus with less mature material structure. The two healing processes separated between 4 and 6 weeks post-osteotomy. The outcome of healing was determined by the varied geometrical conditions in critical and non-critical healing, inducing completely different mechanical situations. PMID:24929204

  6. Novel cerium doped glass-reinforced hydroxyapatite with antibacterial and osteoconductive properties for bone tissue regeneration.

    Science.gov (United States)

    Morais, D S; Fernandes, S; Gomes, P S; Fernandes, M H; Sampaio, P; Ferraz, M P; Santos, J D; Lopes, M A; Sooraj Hussain, N

    2015-09-01

    The aim of this work was to develop a bioactive bone substitute with an effective antibacterial ability based on a cerium (Ce) doped glass-reinforced hydroxyapatite (GR-HA) composite. Developed composites were physicochemically characterized, using x-ray diffraction (XRD) analysis, SEM, energy dispersive x-ray spectroscopy (EDS), and flexural bending strength (FBS) tests. X-ray photoelectron spectroscopy (XPS) analysis was performed to analyze the oxidation state of Ce in the prepared doped glass. The antimicrobial activity of the composites was evaluated against Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa; whether the cytocompatibility profile was assayed with human osteoblastic-like cells (Mg-63 cell line). The results revealed that the Ce inclusion in the GR-HA matrix induced the antimicrobial ability of the composite. In addition, Ce-doped materials reported an adequate biological behavior following seeding of osteoblastic populations, by inducing cell adhesion and proliferation. Developed materials were also found to enhance the expression of osteoblastic-related genes. Overall, the developed GR-HA_Ce composite is a prospective candidate to be used within the clinical scenario with a successful performance due to the effective antibacterial properties and capability of enhancing the osteoblastic cell response. PMID:26391473

  7. Relaxation properties of natural and artificial cellulose materials

    International Nuclear Information System (INIS)

    Present article is devoted to relaxation properties of natural and artificial cellulose materials. Therefore the dielectric properties of natural and artificial cellulose materials depending on influence of frequency and temperature are studied.

  8. BIOMECHANICAL ANALYSIS OF HUMAN FEMUR BONE

    OpenAIRE

    RAJI NARELIYA,; VEERENDRA KUMAR

    2011-01-01

    Biomechanics is the theory of how tissues, cells, muscles, bones, organs and the motion of them and how their form and function are regulated by basic mechanical properties. A finite element model of bones with accurate geometry and material properties retrieved from CT scan data are being widely used to make realistic investigations on the mechanical behavior of bone structures. The aim of this study is to create a model of real proximal human femur bone for evaluating the finite element ana...

  9. Effect of ZrO2 addition on the mechanical properties of porous TiO2 bone scaffolds.

    Science.gov (United States)

    Tiainen, Hanna; Eder, Georg; Nilsen, Ola; Haugen, Håvard J

    2012-08-01

    This study aimed at the investigation of the effect of zirconium dioxide (ZrO2) addition on the mechanical properties of titanium dioxide (TiO2) bone scaffolds. The highly biocompatible TiO2 has been identified as a promising material for bone scaffolds, whereas the more bioinert ZrO2 is known for its excellent mechanical properties. Ultra-porous TiO2 scaffolds (>89% porosity) were produced using polymer sponge replication with 0-40 wt.% of the TiO2 raw material substituted with ZrO2. Microstructure, chemical composition, and pore architectural features of the prepared ceramic foams were characterised and related to their mechanical strength. Addition of 1 wt.% of ZrO2 led to 16% increase in the mean compressive strength without significant changes in the pore architectural parameters of TiO2 scaffolds. Further ZrO2 additions resulted in reduction of compressive strength in comparison to containing no ZrO2. The appearance of zirconium titanate (ZrTiO4) phase was found to hinder the densification of the ceramic material during sintering resulting in poor intergranular connections and thus significantly reducing the compressive strength of the highly porous ceramic foam scaffolds. PMID:24364936

  10. Local mechanical properties of inhomogeneous materials

    International Nuclear Information System (INIS)

    Full text: Materials having discrete inhomogeneities, e.g. composites, are of increasing interest for the modern science and technology. The peculiarity of such materials is stochastic microstructure, that requires to use the probabilistic approaches for modeling of their properties. There are two main problems in the mechanics of composites. The first one deals with the determination of the macroscopic law of Hook: The effective elastic modules, connecting the tensors of average stresses and strains, are required to be calculated in this case. Another one is the evaluation of local fields of stresses (strains), i.e. the problem of the calculation of tensor operators of their concentration. These operators connect the average (external) stresses (strains) in the material with their internal (local) values. These problems are mutually connected, because in any known approximations the solution of stochastic differential equations (the equilibrium equations for elastic mediums with a microstructure) are required in the both case. The determination of local fields of stresses, which exceed the breaking point of the matrix or inclusions, is required for modeling of local damage of composites. Thus, the dependence of local fields of stresses (strains) on a distance between inclusions should be considered as the important property of composites. In this work only matrix composites are discussed. Assuming, that the composite is macroscopically homogeneous, the nonlinear dependence of average distance between inclusions on their bulk concentration is established. The various kinds of approximations are obtained for the evaluation of local fields of stresses and strains, which are similar to approximations of Voigt, Reuss and other authors for the calculation of effective elastic properties. Application of these results allows to establish the dependence between operators of the concentration of stresses (strains) and the average distance between inclusions. In conclusion

  11. Influence of bone morphological properties on a new expandable orthopaedic fastener

    Science.gov (United States)

    Oldakowski, M.; Oldakowska, I.; Kirk, T. B.; Ford, C. T.; Sercombe, T. B.; Hardcastle, P.; Day, R. E.

    2016-03-01

    Previous studies have demonstrated that bone morphological properties are a significant determinant of orthopaedic fastener fixation strength. The authors previously tested a new design of unthreaded expandable fastener (UEF) prototype against screws and demonstrated a significant increase in pull-out strength. However the effect of bone morphology on the pull-out strength of the UEF and expandable fasteners in general is unknown. This study assessed the correlation between failure force and maximum force against five microstructural parameters. The failure force of the UEF was correlated to the trabecular bone volume fraction, as with screws. Unlike screws, however, the maximum force of the UEF has an inverse relationship with cortical volume. No correlation was found between failure force and the Structural Model Index (SMI). Additionally the critical volume of interest (VOI) for the UEF is around the bottom of the fastener where the expansion occurs, whereas for the screw a full height VOI is critical. Furthermore, we observed that screw mechanical performance may be affected more by bone morphological parameters that are associated with poorer quality bone. Therefore the UEF may perform better than screws in low quality osteoporotic bone.

  12. Dual-energy digital radiography in the assessment of bone mechanical properties

    International Nuclear Information System (INIS)

    At present, bone fragility and fracture risk are estimated with bone mineral density (BMD), measured by dual-energy x-ray absorptiometry (DXA). It is known that DXA-based BMD (BMDDXA) has a relationship with mechanical characteristics of bone. Dual-energy digital radiography (DEDR) has also been shown to be a potential method to determine BMD, but the ability of DEDR-based BMD (BMDDEDR) to predict bone mechanical properties is not yet known. In this study, we investigated the ability of BMDDEDR to predict the mechanical characteristics of bone. Reindeer femora (N = 50) were imaged at two different energies (79 and 100 kVp) using a clinical digital radiography system. BMD was determined in four regions from these images using the DXA calculation principle. Femora were mechanically tested using axial loading configuration. Mechanical parameters were correlated with the BMDDEDR and BMDDXA of the femoral neck (FNBMDDEDR and FNBMDDXA). FNBMDDEDR and FNBMDDXA both correlated moderately with mechanical parameters. The highest correlations were found with maximal load (r = 0.53 and r = 0.65, p < 0.01, respectively). No statistically significant differences were found between the correlation coefficients when comparing the FNBMDDEDR or FNBMDDXA values and mechanical parameters. The correlation coefficient between BMDDEDR and BMDDXA varied between r = 0.56 and 0.86 (p < 0.01) in different regions of the upper femur. In conclusion, BMDDEDR predicts the mechanical parameters of reindeer bone with similar accuracy as BMDDXA

  13. A comparative analysis of scaffold material modifications for load-bearing applications in bone tissue engineering

    OpenAIRE

    Chim, H; Hutmacher, D.W.; Chou, A.; de Oliveira, A. L.; Reis, R. L.; Lim, T C; Schantz, J. T.

    2006-01-01

    To facilitate optimal application of appropriate scaffold architectures for clinical trials, there is a need to compare different scaffold modifications under similar experimental conditions. In this study was assessed the effectiveness of poly-e-caprolactone (PCL) scaffolds fabricated by fused deposition modelling (FDM), with varying material modifications, for the purposes of bone tissue engineering. The incorporation of hydroxyapatite (HA) in PCL scaffolds, as well as pre...

  14. Is Macroporosity Absolutely Required for Preliminary in Vitro Bone Biomaterial Study? A Comparison Between Porous Materials and Flat Materials

    Directory of Open Access Journals (Sweden)

    Wai-Hung Tsang

    2011-11-01

    Full Text Available Porous materials are highly preferred for bone tissue engineering due to space for blood vessel ingrowth, but this may introduce extra experimental variations because of the difficulty in precise control of porosity. In order to decide whether it is absolutely necessary to use porous materials in in vitro comparative osteogenesis study of materials with different chemistries, we carried out osteoinductivity study using C3H/10T1/2 cells, pluripotent mesenchymal stem cells (MSCs, on seven material types: hydroxyapatite (HA, α-tricalcium phosphate (α-TCP and b-tricalcium phosphate (β-TCP in both porous and dense forms and tissue culture plastic. For all materials under test, dense materials give higher alkaline phosphatase gene (Alp expression compared with porous materials. In addition, the cell density effects on the 10T1/2 cells were assessed through alkaline phosphatase protein (ALP enzymatic assay. The ALP expression was higher for higher initial cell plating density and this explains the greater osteoinductivity of dense materials compared with porous materials for in vitro study as porous materials would have higher surface area. On the other hand, the same trend of Alp mRNA level (HA > β-TCP > α-TCP was observed for both porous and dense materials, validating the use of dense flat materials for comparative study of materials with different chemistries for more reliable comparison when well-defined porous materials are not available. The avoidance of porosity variation would probably facilitate more reproducible results. This study does not suggest porosity is not required for experiments related to bone regeneration application, but emphasizes that there is often a tradeoff between higher clinical relevance, and less variation in a less complex set up, which facilitates a statistically significant conclusion. Technically, we also show that the base of normalization for ALP activity may influence the conclusion and there may be ALP

  15. Mechanical properties of low dimensional materials

    Science.gov (United States)

    Saini, Deepika

    Recent advances in low dimensional materials (LDMs) have paved the way for unprecedented technological advancements. The drive to reduce the dimensions of electronics has compelled researchers to devise newer techniques to not only synthesize novel materials, but also tailor their properties. Although micro and nanomaterials have shown phenomenal electronic properties, their mechanical robustness and a thorough understanding of their structure-property relationship are critical for their use in practical applications. However, the challenges in probing these mechanical properties dramatically increase as their dimensions shrink, rendering the commonly used techniques inadequate. This dissertation focuses on developing techniques for accurate determination of elastic modulus of LDMs and their mechanical responses under tensile and shear stresses. Fibers with micron-sized diameters continuously undergo tensile and shear deformations through many phases of their processing and applications. Significant attention has been given to their tensile response and their structure-tensile properties relations are well understood, but the same cannot be said about their shear responses or the structure-shear properties. This is partly due to the lack of appropriate instruments that are capable of performing direct shear measurements. In an attempt to fill this void, this dissertation describes the design of an inexpensive tabletop instrument, referred to as the twister, which can measure the shear modulus (G) and other longitudinal shear properties of micron-sized individual fibers. An automated system applies a pre-determined twist to the fiber sample and measures the resulting torque using a sensitive optical detector. The accuracy of the instrument was verified by measuring G for high purity copper and tungsten fibers. Two industrially important fibers, IM7 carbon fiber and KevlarRTM 119, were found to have G = 17 and 2.4 GPa, respectively. In addition to measuring the shear

  16. Collagen and mineral deposition in rabbit cortical bone during maturation and growth: effects on tissue properties.

    Science.gov (United States)

    Isaksson, Hanna; Harjula, Terhi; Koistinen, Arto; Iivarinen, Jarkko; Seppänen, Kari; Arokoski, Jari P A; Brama, Pieter A; Jurvelin, Jukka S; Helminen, Heikki J

    2010-12-01

    We characterized the composition and mechanical properties of cortical bone during maturation and growth and in adult life in the rabbit. We hypothesized that the collagen network develops earlier than the mineralized matrix. Growth was monitored, and the rabbits were euthanized at birth (newborn), and at 1, 3, 6, 9, and 18 months of age. The collagen network was assessed biochemically (collagen content, enzymatic and non-enzymatic cross-links) in specimens from the mid-diaphysis of the tibia and femur and biomechanically (tensile testing) from decalcified whole tibia specimens. The mineralized matrix was analyzed using pQCT and 3-point bend tests from intact femur specimens. The collagen content and the Young's modulus of the collagen matrix increased significantly until the rabbits were 3 months old, and thereafter remained stable. The amount of HP and LP collagen cross-links increased continuously from newborn to 18 months of age, whereas PEN cross-links increased after 6 months of age. Bone mineral density and the Young's modulus of the mineralized bone increased until the rabbits were at least 6 months old. We concluded that substantial changes take place during the normal process of development in both the biochemical and biomechanical properties of rabbit cortical bone. In cortical bone, the collagen network reaches its mature composition and mechanical strength prior to the mineralized matrix. PMID:20540098

  17. Murine patellar tendon biomechanical properties and regional strain patterns during natural tendon-to-bone healing after acute injury

    Science.gov (United States)

    Gilday, Steven D.; Casstevens, E. Chris; Kenter, Keith; Shearn, Jason T.; Butler, David L.

    2014-01-01

    Tendon-to-bone healing following acute injury is generally poor and often fails to restore normal tendon biomechanical properties. In recent years, the murine patellar tendon (PT) has become an important model system for studying tendon healing and repair due to its genetic tractability and accessible location within the knee. However, the mechanical properties of native murine PT, specifically the regional differences in tissue strains during loading, and the biomechanical outcomes of natural PT-to-bone healing have not been well characterized. Thus, in this study, we analyzed the global biomechanical properties and regional strain patterns of both normal and naturally healing murine PT at three time points (2, 5, and 8 weeks) following acute surgical rupture of the tibial enthesis. Normal murine PT exhibited distinct regional variations in tissue strain, with the insertion region experiencing approximately 2.5 times greater strain than the midsubstance at failure (10.80 ± 2.52% vs. 4.11 ± 1.40%; mean ± SEM). Injured tendons showed reduced structural (ultimate load and linear stiffness) and material (ultimate stress and linear modulus) properties compared to both normal and contralateral sham-operated tendons at all healing time points. Injured tendons also displayed increased local strain in the insertion region compared to contralateral shams at both physiologic and failure load levels. 93.3% of injured tendons failed at the tibial insertion, compared to only 60% and 66.7% of normal and sham tendons, respectively. These results indicate that 8 weeks of natural tendon-to-bone healing does not restore normal biomechanical function to the murine PT following injury. PMID:24210849

  18. Microindentation for in vivo measurement of bone tissue mechanical properties in humans.

    Science.gov (United States)

    Diez-Perez, Adolfo; Güerri, Roberto; Nogues, Xavier; Cáceres, Enric; Peña, Maria Jesus; Mellibovsky, Leonardo; Randall, Connor; Bridges, Daniel; Weaver, James C; Proctor, Alexander; Brimer, Davis; Koester, Kurt J; Ritchie, Robert O; Hansma, Paul K

    2010-08-01

    Bone tissue mechanical properties are deemed a key component of bone strength, but their assessment requires invasive procedures. Here we validate a new instrument, a reference point indentation (RPI) instrument, for measuring these tissue properties in vivo. The RPI instrument performs bone microindentation testing (BMT) by inserting a probe assembly through the skin covering the tibia and, after displacing periosteum, applying 20 indentation cycles at 2 Hz each with a maximum force of 11 N. We assessed 27 women with osteoporosis-related fractures and 8 controls of comparable ages. Measured total indentation distance (46.0 +/- 14 versus 31.7 +/- 3.3 microm, p = .008) and indentation distance increase (18.1 +/- 5.6 versus 12.3 +/- 2.9 microm, p = .008) were significantly greater in fracture patients than in controls. Areas under the receiver operating characteristic (ROC) curve for the two measurements were 93.1% (95% confidence interval [CI] 83.1-100) and 90.3% (95% CI 73.2-100), respectively. Interobserver coefficient of variation ranged from 8.7% to 15.5%, and the procedure was well tolerated. In a separate study of cadaveric human bone samples (n = 5), crack growth toughness and indentation distance increase correlated (r = -0.9036, p = .018), and scanning electron microscope images of cracks induced by indentation and by experimental fractures were similar. We conclude that BMT, by inducing microscopic fractures, directly measures bone mechanical properties at the tissue level. The technique is feasible for use in clinics with good reproducibility. It discriminates precisely between patients with and without fragility fracture and may provide clinicians and researchers with a direct in vivo measurement of bone tissue resistance to fracture. PMID:20200991

  19. Evaluation of hydroxyapatite and beta-tricalcium phosphate mixed with bone marrow aspirate as a bone graft substitute for posterolateral spinal fusion

    OpenAIRE

    Bansal Sanjay; Chauhan Vijendra; Sharma Sansar; Maheshwari Rajesh; Juyal Anil; Raghuvanshi Shailendra

    2009-01-01

    Background: Autologous cancellous bone is the most effective biological graft material. However, harvest of autologous bone is associated with significant morbidity. Since porous hydroxyapatite and beta-tricalcium phosphate are biodegradable materials and can be replaced by bone tissue, but it lacks osteogenic property. We conducted a study to assess their use as a scaffold and combine them with bone marrow aspirate for bone regeneration using its osteogenic property for posterolateral spina...

  20. A biocompatible hybrid material with simultaneous calcium and strontium release capability for bone tissue repair.

    Science.gov (United States)

    Almeida, J Carlos; Wacha, András; Gomes, Pedro S; Alves, Luís C; Fernandes, M Helena Vaz; Salvado, Isabel M Miranda; Fernandes, M Helena R

    2016-05-01

    The increasing interest in the effect of strontium in bone tissue repair has promoted the development of bioactive materials with strontium release capability. According to literature, hybrid materials based on the system PDMS-SiO2 have been considered a plausible alternative as they present a mechanical behavior similar to the one of the human bone. The main purpose of this study was to obtain a biocompatible hybrid material with simultaneous calcium and strontium release capability. A hybrid material, in the system PDMS-SiO2-CaO-SrO, was prepared with the incorporation of 0.05mol of titanium per mol of SiO2. Calcium and strontium were added using the respective acetates as sources, following a sol-gel technique previously developed by the present authors. The obtained samples were characterized by FT-IR, solid-state NMR, and SAXS, and surface roughness was analyzed by 3D optical profilometry. In vitro studies were performed by immersion of the samples in Kokubo's SBF for different periods of time, in order to determine the bioactive potential of these hybrids. Surfaces of the immersed samples were observed by SEM, EDS and PIXE, showing the formation of calcium phosphate precipitates. Supernatants were analyzed by ICP, revealing the capability of the material to simultaneously fix phosphorus ions and to release calcium and strontium, in a concentration range within the values reported as suitable for the induction of the bone tissue repair. The material demonstrated to be cytocompatible when tested with MG63 osteoblastic cells, exhibiting an inductive effect on cell proliferation and alkaline phosphatase activity. PMID:26952443

  1. Low-level laser therapy, at 60 J/cm2 associated with a Biosilicate® increase in bone deposition and indentation biomechanical properties of callus in osteopenic rats

    Science.gov (United States)

    Fangel, Renan; Sérgio Bossini, Paulo; Cláudia Renno, Ana; Araki Ribeiro, Daniel; Chenwei Wang, Charles; Luri Toma, Renata; Okino Nonaka, Keico; Driusso, Patrícia; Antonio Parizotto, Nivaldo; Oishi, Jorge

    2011-07-01

    We investigate the effects of a novel bioactive material (Biosilicate®) and low-level laser therapy (LLLT), at 60 J/cm2, on bone-fracture consolidation in osteoporotic rats. Forty female Wistar rats are submitted to the ovariectomy, to induce osteopenia. Eight weeks after the ovariectomy, the animals are randomly divided into four groups, with 10 animals each: bone defect control group; bone defect filled with Biosilicate group; bone defect irradiated with laser at 60 J/cm2 group; bone defect filled with Biosilicate and irradiated with LLLT, at 60 J/cm2 group. Laser irradiation is initiated immediately after surgery and performed every 48 h for 14 days. Histopathological analysis points out that bone defects are predominantly filled with the biomaterial in specimens treated with Biosilicate. In the 60-J/cm2 laser plus Biosilicate group, the biomaterial fills all bone defects, which also contained woven bone and granulation tissue. Also, the biomechanical properties are increased in the animals treated with Biosilicate associated to lasertherapy. Our results indicate that laser therapy improves bone repair process in contact with Biosilicate as a result of increasing bone formation as well as indentation biomechanical properties.

  2. Vibrational spectroscopy in biomedical science: bone

    Science.gov (United States)

    Gamsjäger, Sonja; Zoehrer, R.; Roschger, P.; Fratzl, P.; Klaushofer, K.; Mendelsohn, R.; Paschalis, E. P.

    2009-02-01

    Fourier transform infrared imaging (FTIR) and Raman Microspectroscopy are powerful tools for characterizing the distribution of different chemical moieties in heterogeneous materials. FTIR and Raman measurements have been adapted to assess the maturity of the mineral and the quality of the organic component (collagen and non-collagenous proteins) of the mineralized tissue in bone. Unique to the FTIRI analysis is the capability to provide the spatial distribution of two of the major collagen cross-links (pyridinoline, and dehydro-dihydroxylysinonorleucine) and through the study of normal and diseased bone, relate them to bone strength. These FTIR parameters have been validated based on analysis of model compounds. It is widely accepted that bone strength is determined by bone mass and bone quality. The latter is a multifactorial term encompassing the material and structural properties of bone, and one important aspect of the bone material properties is the organic matrix. The bone material properties can be defined by parameters of mineral and collagen, as determined by FTIR and Raman analysis. Considerably less attention has been directed at collagen, although there are several publications in the literature reporting altered collagen properties associated with fragile bone, in both animals and humans. Since bone is a heterogeneous tissue due to the remodeling process, microscopic areas may be carefully selected based on quantitative Backscattered Electron Imaging or histological staining, thus ensuring comparison of areas with similar metabolic activity and mineral content. In conclusion, FTIRI and Raman vibrational spectroscopy are proving to be powerful tools in bone-related medical research.

  3. Calculation of material properties and ray tracing in transformation media

    OpenAIRE

    Schurig, D.; J. B. Pendry; Smith, D R

    2006-01-01

    Complex and interesting electromagnetic behavior can be found in spaces with non-flat topology. When considering the properties of an electromagnetic medium under an arbitrary coordinate transformation an alternative interpretation presents itself. The transformed material property tensors may be interpreted as a different set of material properties in a flat, Cartesian space. We describe the calculation of these material properties for coordinate transformations that describe spaces with sph...

  4. Sex-Specific Differences of Moderate Iron Elevations on Bone Mechanical Properties

    Science.gov (United States)

    Bokhari, R. S.; Metzger, C. E.; Allen, M. R.; Lenfest, S.; Seidel, D.; Hogan, H. A.; Turner, N. D.; Zwart, S. R.; Bloomfield, S. A.

    2016-01-01

    Moderate elevations in iron stores accelerate loss of BMD in middle-aged men and women over 40 years, but are associated with elevated vertebral fracture incidence in women only (Kim et al. JBMR 2012). To further explore potential sex differences in the response to elevated iron stores, we tested the hypothesis that increasing iron stores would lead to bone loss. Male and female C57BL/6 mice (n=21 male and n=25 female; age 16 wks) were fed AIN93-G purified diet with normal (45 mg Fe/kg, CC) or high (650 mg Fe/kg, Fe) iron content. After 8 weeks on the diet, liver iron in both FE groups was approximately 28% higher than in CC. Males and females on FE diet respectively had 38% and 33% greater distal femur cancellous BV/TV than control animals (all values at a level of p sex with elevated iron. Serum measures of C-terminal telopeptides (CTX) of type 1 collagen were found to be 10% greater in FE females with no change in males (psexes following iron treatment, structural mechanical properties were only enhanced in males. This suggests sex- specific differences exist at the material level (collagen, mineral) in response to elevated dietary iron.

  5. Biodegradation rate of shellac coated bovine hydroxyapatite for bone filler material

    Science.gov (United States)

    Triyono, Joko; Triyono, Susilowati, Endang; Murdiyantara, Suci Anindya

    2016-03-01

    This work reports on the effect of shellac coated hydroxyapatite (HA) on the biodegradation rate. The HA was processed from bovine bone. Shellac was derived from the resinous secretion of the lac insect. The aims of the addition of shellac solution is to know how the biodegradation rate material in the Phosphate Buffered Saline (PBS) solution. The four different of shellac solutions (2,5%; 5%; 7,5%; and 10% weight) coated HA scaffoldand one ratio as a control. It was concluded that the ability of biodegradation rate a materialwas not influenced by the ratio of shellac. All materials were biodegradedwhen they were soaked in PBS solution.

  6. 脱蛋白松质骨作为异种骨移植材料的修复作用%Repair effect of deproteinised cancellous bone as xenogeneic bone graft material

    Institute of Scientific and Technical Information of China (English)

    高春阳; 姜宏春; 金春明

    2011-01-01

    BACKGROUND: Unequal size, mutual communication, and open pore network structure can be seen in cancellous bone treated with deproteinization. Its inorganic component is hydroxyapatite, and the organic component is collagen, which has a good mechanical property and biocompatibility. It may be a new type of bone graft material.OBJECTIVE: To study the properties of xenogeneic deproteinised cancellous bone being carrier of bone tissue engineering in bone fusion.METHODS: Taking “xenogeneic deproteinised cancellous bone, bone fusion, carrier” in Chinese as search terms, the articles from January 1998 to December 2009 in VIP database, CNKI database, Pubmed database were retrieved by computer. The relevant literatures were included, the literature of irrelevant purpose and repetitive content were excluded, and 33 of them were involved for further analysis.RESULTS AND CONCLUSION: Compared with synthetic bone material, animal bones have similar biomaterial structure, modeling, excellent cell attachment, and cell growth and proliferation environment. However, the compatibility of bone tissue is poor, because of the differences in species when xenogeneic deproteinised cancellous bone transplantation, and gravis immune rejection, the key question is implantation of immune problems. How to overcome immunogenicity, xenogeneic deproteinised cancellous bone is a good carrier of bone tissue engineering, which can provide a stable environment for revascularization and differentiation of osteoblasts.%背景:采用脱蛋白处理后的松质骨可见大小不等、相互交通、开放孔隙的网架结构,其无机成分为羟基磷灰石,有机成分为胶原,力学性能保存良好,有良好的细胞相容性,可能是一种新型骨移植材料.目的:介绍异种脱蛋白松质骨作为骨组织工程载体的性能,以及其用于骨融合的作用.方法:分别以"异种脱蛋白松质骨、骨融合、载体",为检索词,应用计算机检索重庆

  7. Effects of long-term administration of omeprazole on bone mineral density and the mechanical properties of the bone

    Directory of Open Access Journals (Sweden)

    Gabriela Rezende Yanagihara

    2015-04-01

    Full Text Available OBJECTIVES: Epidemiological studies have shown a relationship between long-term use of proton pump inhibitors and bone metabolism. However, this relationship has not yet become established. The aim of the present study was to analyze the mechanical properties and bone mineral density (BMD of rats that were subjected to long-term omeprazole use.METHODS: Fifty Wistar rats weighing between 200 and 240 g were divided equally into five groups: OMP300 (omeprazole intake at a dose of 300 µmoL/kg/day; OMP200 (200 µmoL/kg/day; OMP40 (40 µmoL/kg/day; OMP10 (10 µmoL/kg/day; and Cont (control group; intake of dilution vehicle. The solutions were administered for 90 consecutive days. After the rats had been sacrificed, their BMD, the mechanical properties of the dissected femurs and their serum Ca++ levels were analyzed.RESULTS: The BMD of the OMP300 group was lower than that of the controls (p = 0.006. There was no difference on comparing the OMP200, OMP40 and OMP10 groups with the controls. The maximum strength and rigidity of the femur did not differ in the experimental groups in comparison with the controls. The OMP300 group had a statistically lower serum Ca++ concentration than that of the controls (p = 0.049, but the other groups did not show any difference in relation to the controls.CONCLUSION: Daily intake of 300 µmoL/kg/day of omeprazole decreased the BMD of the femur, but without changes to the rigidity and strength of the femur in adult rats.

  8. Age- and gender-related distribution of bone mineral density and mechanical properties of the proximal humerus

    International Nuclear Information System (INIS)

    Purpose: To evaluate age- and gender-related mechanical properties and bone mineral density (BMD) of the proximal humerus at different levels and regions. Materials and methods: Mechanical indentation testing, DXA, QCT, pQCT and the radiogrammetry (Cortical Index, CI) were carried out in 70 freshly harvested humeri from 46 human cadavers (23 females, 23-males; median age 70.5 years). Results: In the female group, a high correlation between age and BMD was found (ρ=0.62 to -0.70, p<0.01) with statistically significant differences between specimens of patients 69 years or younger, and 70 years or older (p<0.05). In the group of female specimens of age 70 years or older, BMD values were found to be significantly lower compared to their male counterparts (p<0.05). Regardless of the specimen's age, the highest BMD and bone strength were found in the proximal aspect and in the medial and dorsal regions of the proximal humerus. Conclusion: These findings provide an insight into the fracture mechanism of the proximal humerus and should be the basis for designing structure-oriented implants with improved implant-bone stability in osteoporotic patients. (orig.)

  9. Material properties and biochemical composition of mineralized vertebral cartilage in seven elasmobranch species (Chondrichthyes).

    Science.gov (United States)

    Porter, Marianne E; Beltrán, Jennie L; Koob, Thomas J; Summers, Adam P

    2006-08-01

    Elasmobranchs, particularly sharks, function at speed and size extremes, exerting large forces on their cartilaginous skeletons while swimming. This casts doubt on the generalization that cartilaginous skeletons are mechanically inferior to bony skeletons, a proposition that has never been experimentally verified. We tested mineralized vertebral centra from seven species of elasmobranch fishes: six sharks and one axially undulating electric ray. Species were chosen to represent a variety of morphologies, inferred swimming speeds and ecological niches. We found vertebral cartilage to be as stiff and strong as mammalian trabecular bone. Inferred swimming speed was a good, but not infallible, predictor of stiffness and strength. Collagen content was also a good predictor of material stiffness and strength, although proteoglycan was not. The mineral fraction in vertebral cartilage was similar to that in mammalian trabecular bone and was a significant predictor of material properties. PMID:16857876

  10. Understanding and Predicting the Properties of Complex Materials

    DEFF Research Database (Denmark)

    Smedskjær, Morten Mattrup; Mauro, John C.; Yue, Yuanzheng

    Predicting the properties of new materials prior to manufacturing is a topic attracting great industrial and scientific interest. Mechanical properties are currently of particular interest given the increasing demand for stronger, thinner, and more flexible materials in recent years. Property pre...... and viscosity can be quantitatively predicted for oxide network glasses of industrial interest, such as borates and borosilicates....

  11. 46 CFR 164.013-3 - Material properties and workmanship.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Material properties and workmanship. 164.013-3 Section..., Slitted Trigonal Pattern) § 164.013-3 Material properties and workmanship. (a) General. The unicellular polyethylene foam shall be all new material complying with the requirements outlined in this...

  12. The effect of osteoporosis treatments on fatigue properties of cortical bone tissue

    Directory of Open Access Journals (Sweden)

    Garry R. Brock

    2015-06-01

    Full Text Available Bisphosphonates are commonly prescribed for treatment of osteoporosis. Long-term use of bisphosphonates has been correlated to atypical femoral fractures (AFFs. AFFs arise from fatigue damage to bone tissue that cannot be repaired due to pharmacologic treatments. Despite fatigue being the primary damage mechanism of AFFs, the effects of osteoporosis treatments on fatigue properties of cortical bone are unknown. To examine if fatigue-life differences occur in bone tissue after different pharmacologic treatments for osteoporosis, we tested bone tissue from the femurs of sheep given a metabolic acidosis diet to induce osteoporosis, followed by treatment with a selective estrogen reception modulator (raloxifene, a bisphosphonate (alendronate or zoledronate, or parathyroid hormone (teriparatide, PTH. Beams of cortical bone tissue were created and tested in four-point bending fatigue to failure. Tissue treated with alendronate had reduced fatigue life and less modulus loss at failure compared with other treatments, while tissue treated with PTH had a prolonged fatigue life. No loss of fatigue life occurred with zoledronate treatment despite its greater binding affinity and potency compared with alendronate. Tissue mineralization measured by microCT did not explain the differences seen in fatigue behavior. Increased fatigue life with PTH suggests that current treatment methods for AFF could have beneficial effects for restoring fatigue life. These results indicate that fatigue life differs with each type of osteoporosis treatment.

  13. Biosilica-glass formation using enzymes from sponges [silicatein]: Basic aspects and application in biomedicine [bone reconstitution material and osteoporosis

    Science.gov (United States)

    Wang, Shun-Feng; Wang, Xiao-Hong; Gan, Lu; Wiens, Matthias; Schröder, Heinz C.; Müller, Werner E. G.

    2011-09-01

    In the last 15 years biomineralization, in particular biosilicification (i.e., the formation of biogenic silica, SiO2), has become an exciting source of inspiration for the development of novel bionic approaches, following "Nature as model". Among the silica forming organisms there are the sponges that have the unique property to catalyze their silica skeletons by a specific enzyme termed silicatein. In the present review we summarize the present state of knowledge on silicatein-mediated "biosilica" formation in marine sponges, the involvement of further molecules in silica metabolism and their potential application in biomedicine. Recent advancements in the production of bone replacement material and in the potential use as a component in the treatment of osteoporosis are highlighted.

  14. New bone implant material with calcium sulfate and Ti modified hydroxyapatite

    Directory of Open Access Journals (Sweden)

    A. Ślósarczyk

    2010-11-01

    Full Text Available (TiHA to develop a novel bone cement. Results of previous studies showed that bioactive potential of titanium modified hydroxyapatite ceramics is higher than that of pure HA. Calcium sulfate hemihydrate is also considered as a safe, biocompatible material, however it has been criticized for its rapid resorption. Combination of these materials may result in new cement type material with surgical handiness and selective resorption.Design/methodology/approach: TiHA was obtained by a wet method. Three compositions with different CSH:TiHA weight ratios, namely 3:2, 2:3 and 1:4 were examined. Pure CSH was used as a reference. Distilled water and Na2HPO4 solutions were applied as liquid phases. The study presents the setting time (Gillmore apparatus, phase composition (XRD, microstructure (SEM, porosity (mercury porosimetry and compressive strength of the obtained new, cement type, implant material.Findings: Initial (I and final (F setting times of the obtained cements differed in the range of 2-16 min (I and 4-75 min (F. The phase composition of the hardened cement bodies characterized by XRD method revealed the presence of calcium sulfate dihydrate (CSD and hydroxyapatite. Scanning electron microscopy images show excellent bonding between needle-like CSD crystals and apatitic phase. Porosity of the final samples varied from 49 to 59% with pore size diameter from 5 nm to 3.0 μm. Compressive strength of the samples differed in the range of 3.81-7.58 MPa.Research limitations/implications: The obtained results suggest that CSH-TiHA cements have the potential to be applied in bone substitution and for delivery of drugs. Bioactivity and biodegradation of the studied materials should be checked.Originality/value: According to our knowledge, these are the first studies concerning surgical handiness of bone implant materials based on calcium sufate hemihydrate and titanium doped hydroxyapatite. The cement type composites are biocompatible, shapeable and easy

  15. Improvement of in vitro physicochemical properties and osteogenic activity of calcium sulfate cement for bone repair by dicalcium silicate

    International Nuclear Information System (INIS)

    Highlights: • Dicalcium silicate can improve osteogenic activity of calcium sulfate cement. • The higher the calcium sulfate content, the shorter the setting time in the composite cement. • The results were useful for designing calcium-based cement with optimal properties. -- Abstract: An ideal bone graft substitute should have the same speed of degradation as formation of new bone tissue. To improve the properties of calcium sulfate hemihydrate (CSH) featured for its rapid resorption, a low degradation material of dicalcium silicate (DCS) was added to the CSH cement. This study examined the effect of DCS (20, 40, 60 and 80 wt%) on the in vitro physicochemical properties and osteogenic activities of the calcium-based composite cements. The diametral tensile strength, porosity and weight loss of the composite cements were evaluated before and after soaking in a simulated body fluid (SBF). The osteogenic activities, such as proliferation, differentiation and mineralization, of human mesenchymal stem cells (hMSCs) seeded on cement surfaces were also examined. As a result, the greater the DCS amount, the higher the setting time was in the cement. Before soaking in SBF, the diametral tensile strength of the composite cements was decreased due to the introduction of DCS. On 180-day soaking, the composite cements containing 20, 40, 60 and 80 wt% DCS lost 80%, 69%, 61% and 44% in strength, respectively. Regarding in vitro bioactivity, the DCS-rich cements were covered with clusters of apatite spherulites after soaking for 7 days, while there was no formation of apatite spherulites on the CSH-rich cement surfaces. The presence of DCS could reduce the degradation of the CSH cements, as evidenced in the results of weight loss and porosity. More importantly, DCS may promote effectively the cell proliferation, proliferation and mineralization. The combination of osteogenesis of DCS and degradation of CSH made the calcium-based composite cements an attractive choice for

  16. Preparation and mechanical property of a novel 3D porous magnesium scaffold for bone tissue engineering

    International Nuclear Information System (INIS)

    Porous magnesium has been recently recognized as a biodegradable metal for bone substitute applications. A novel porous Mg scaffold with three-dimensional (3D) interconnected pores and with a porosity of 33–54% was produced by the fiber deposition hot pressing (FDHP) technology. The microstructure and morphologies of the porous Mg scaffold were characterized by scanning electron microscopy (SEM), and the effects of porosities on the microstructure and mechanical properties of the porous Mg were investigated. Experimental results indicate that the measured Young's modulus and compressive strength of the Mg scaffold are ranged in 0.10–0.37 GPa, and 11.1–30.3 MPa, respectively, which are fairly comparable to those of cancellous bone. Such a porous Mg scaffold having a 3D interconnected network structure has the potential to be used in bone tissue engineering. - Highlights: • A novel porous Mg was produced by a fiber deposition hot pressing technology. • The porous Mg has a 3D interconnected network structure with a porosity of 33-54%. • Mechanical properties of the porous Mg are comparable to those of cancellous bone

  17. Using calcium silicate to regulate the physicochemical and biological properties when using β-tricalcium phosphate as bone cement

    International Nuclear Information System (INIS)

    β-Tricalcium phosphate (β-TCP) is an osteoconductive material. For this research we have combined it with a low degradation calcium silicate (CS) to enhance its bioactive and osteostimulative properties. To check its effectiveness, a series of β-TCP/CS composites with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Regarding the formation of bone-like apatite, the diametral tensile strength as well as the ion release and weight loss of composites were compared both before and after immersions in simulated body fluid (SBF). In addition, we also examined the behavior of human dental pulp cells (hDPCs) cultured on β-TCP/CS composites. The results show that the apatite deposition ability of the β-TCP/CS composites improves as the CS content is increased. For composites with more than a 60% CS content, the samples become completely covered by a dense bone-like apatite layer. At the end of the immersion period, weight losses of 24%, 32%, 34%, 38%, 41%, and 45% were observed for the composites containing 0%, 20%, 40%, 80%, 80% and 100% β-TCP cements, respectively. In addition, the antibacterial activity of CS/β-TCP composite improves as the CS-content is increased. In vitro cell experiments show that the CS-rich composites promote human dental pulp cell (hDPC) proliferation and differentiation. However, when the CS quantity in the composite is less than 60%, the quantity of cells and osteogenesis protein of hDPCs is stimulated by Si released from the β-TCP/CS composites. The degradation of β-TCP and the osteogenesis of CS give strong reason to believe that these calcium-based composite cements will prove to be effective bone repair materials. - Highlights: • CS improved the physicochemical properties and osteogenic activity of β-TCP. • Higher CS in the composite, the shorter setting time and the higher DTS was found. • With a CS more than 40%, the osteogenesis and angiogenesis proteins were promoted by

  18. Using calcium silicate to regulate the physicochemical and biological properties when using β-tricalcium phosphate as bone cement

    Energy Technology Data Exchange (ETDEWEB)

    Kao, Chia-Tze; Huang, Tsui-Hsien [School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Chen, Yi-Jyun [School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Dental Department, Taichung Hospital, Ministry of Health and Welfare, Taichung City, Taiwan (China); Hung, Chi-Jr [School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Lin, Chi-Chang, E-mail: chichang31@gmail.com [Department of Chemical and Materials Engineering, Tunghai University, Taichung, Taiwan (China); Shie, Ming-You, E-mail: eviltacasi@gmail.com [Department of Chemical and Materials Engineering, Tunghai University, Taichung, Taiwan (China)

    2014-10-01

    β-Tricalcium phosphate (β-TCP) is an osteoconductive material. For this research we have combined it with a low degradation calcium silicate (CS) to enhance its bioactive and osteostimulative properties. To check its effectiveness, a series of β-TCP/CS composites with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Regarding the formation of bone-like apatite, the diametral tensile strength as well as the ion release and weight loss of composites were compared both before and after immersions in simulated body fluid (SBF). In addition, we also examined the behavior of human dental pulp cells (hDPCs) cultured on β-TCP/CS composites. The results show that the apatite deposition ability of the β-TCP/CS composites improves as the CS content is increased. For composites with more than a 60% CS content, the samples become completely covered by a dense bone-like apatite layer. At the end of the immersion period, weight losses of 24%, 32%, 34%, 38%, 41%, and 45% were observed for the composites containing 0%, 20%, 40%, 80%, 80% and 100% β-TCP cements, respectively. In addition, the antibacterial activity of CS/β-TCP composite improves as the CS-content is increased. In vitro cell experiments show that the CS-rich composites promote human dental pulp cell (hDPC) proliferation and differentiation. However, when the CS quantity in the composite is less than 60%, the quantity of cells and osteogenesis protein of hDPCs is stimulated by Si released from the β-TCP/CS composites. The degradation of β-TCP and the osteogenesis of CS give strong reason to believe that these calcium-based composite cements will prove to be effective bone repair materials. - Highlights: • CS improved the physicochemical properties and osteogenic activity of β-TCP. • Higher CS in the composite, the shorter setting time and the higher DTS was found. • With a CS more than 40%, the osteogenesis and angiogenesis proteins were promoted by

  19. Acoustic cloaking transformations from attainable material properties

    International Nuclear Information System (INIS)

    We propose a general methodology and a set of practical recipes for the construction of ultra-broadband acoustic cloaks-structures that can render themselves and a concealed object undetectable by means of acoustic scattering. The acoustic cloaks presented here are designed and function analogously to electromagnetic cloaks. However, acoustic cloaks in a fluid medium do not suffer the bandwidth limitations imposed on their electromagnetic counterparts by the finite speed of light in vacuum. In the absence of specific metamaterials having arbitrary combinations of quasi-static speed of sound and mass density, we explore the flexibility of continuum transformations that produce approximate cloaking solutions. We show that an imperfect, eikonal acoustic cloak (that is, one which is not impedance matched but is valid in the geometrical optics regime) with negligible dispersion can be designed using a simple layered geometry. Since a practical cloaking device will probably be composed of combinations of solid materials rather than fluids, it is necessary to consider the full elastic properties of such media, which support shear waves in addition to the compression waves associated with the acoustic regime. We perform a systematic theoretical and numerical investigation of the role of shear waves in elastic cloaking devices. We find that for elastic metamaterials with Poisson's ratio ν>0.49, shear waves do not alter the cloaking effect. Such metamaterials can be built from nearly incompressible rubbers (with ν∼0.499) and fluids. We expect this finding to have applications in other acoustic devices based on the form-invariance of the scalar acoustic wave equation.

  20. Acoustic cloaking transformations from attainable material properties

    Energy Technology Data Exchange (ETDEWEB)

    Urzhumov, Yaroslav; Ghezzo, Fabrizia; Hunt, John; Smith, David R, E-mail: yaroslav.urzhumov@duke.ed [Center for Metamaterials and Integrated Plasmonics, Pratt School of Engineering, Duke University, Durham, NC 27708 (United States)

    2010-07-15

    We propose a general methodology and a set of practical recipes for the construction of ultra-broadband acoustic cloaks-structures that can render themselves and a concealed object undetectable by means of acoustic scattering. The acoustic cloaks presented here are designed and function analogously to electromagnetic cloaks. However, acoustic cloaks in a fluid medium do not suffer the bandwidth limitations imposed on their electromagnetic counterparts by the finite speed of light in vacuum. In the absence of specific metamaterials having arbitrary combinations of quasi-static speed of sound and mass density, we explore the flexibility of continuum transformations that produce approximate cloaking solutions. We show that an imperfect, eikonal acoustic cloak (that is, one which is not impedance matched but is valid in the geometrical optics regime) with negligible dispersion can be designed using a simple layered geometry. Since a practical cloaking device will probably be composed of combinations of solid materials rather than fluids, it is necessary to consider the full elastic properties of such media, which support shear waves in addition to the compression waves associated with the acoustic regime. We perform a systematic theoretical and numerical investigation of the role of shear waves in elastic cloaking devices. We find that for elastic metamaterials with Poisson's ratio {nu}>0.49, shear waves do not alter the cloaking effect. Such metamaterials can be built from nearly incompressible rubbers (with {nu}{approx}0.499) and fluids. We expect this finding to have applications in other acoustic devices based on the form-invariance of the scalar acoustic wave equation.

  1. Measurement and Recording of Reflective Properties of Materials

    OpenAIRE

    Bálský, Marek; Habel, Jiří

    2015-01-01

    The aim of this paper is to analyse possibilities of measurement of reflective properties of materials used in the interior and to propose methods of recording of measured reflective properties of materials for calculation of multiple reflections in light scenes. One of the basic assumptions for definition of the appropriate methods of recording of measured reflective properties of materials is the analysis of input data and methods used for the calculation of multiple light reflections in co...

  2. Utilization of electric properties of granular and powdery materials

    OpenAIRE

    Z. HlaváÄÂová

    2005-01-01

    Determination of electrical properties is utilized in a wide range of disciplines and industries. A brief compendium of electrical properties utilization of granular and powdery agricultural and food materials is presented in this paper. Electrical properties of granular and powdery materials are influenced by various factors. The most important are moisture content and its distribution in materials, temperature, density, volume or bulk density. The relationships between the resistivity, cond...

  3. Physical and chemical characterisation of crude meat and bone meal combustion residue: 'waste or raw material?'

    International Nuclear Information System (INIS)

    As a result of the recent bovine spongiform encephalopathy (BSE) crisis in the European beef industry, the use of animal by-product is now severely controlled. Meat and bone meal (MBM) production can no longer be used to feed cattle and must be safely disposed of or transformed. Main disposal option is incineration, producing huge amounts of ashes the valorisation of which becomes a major concern. The aim of this work is to characterise MBM combustion residue in order to evaluate their physical and chemical properties to propose new valorisation avenues. The thermal behaviour of crude meat and bone meal was followed by thermogravimetric analysis (TGA) and (24 wt.%) inorganic residue was collected. The resulting ashes were characterised by powder X-ray diffraction (XRD), particle size distribution, specific surface area (BET), scanning electron microscopy (SEM) couple with energy disperse X-ray analysis (EDX). Elemental analysis revealed the presence of chloride, sodium, potassium, magnesium with high level of phosphate (56 wt.%) and calcium (31 wt.%), two major constituents of bone, mainly as a mixture of Ca10(PO4)6(OH)2 and Ca3(PO4)2 phases. The impact of combustion temperature (from 550 to 1000 deg. C) on the constitution of ashes was followed by TGA, XRD and specific surface measurements. We observed a strong decrease of surface area for the ashes with crystallisation of calcium phosphates phases without major changes of chemical composition

  4. Adynamic Bone Decreases Bone Toughness During Aging by Affecting Mineral and Matrix.

    Science.gov (United States)

    Ng, Adeline H; Omelon, Sidney; Variola, Fabio; Allo, Bedilu; Willett, Thomas L; Alman, Benjamin A; Grynpas, Marc D

    2016-02-01

    Adynamic bone is the most frequent type of bone lesion in patients with chronic kidney disease; long-term use of antiresorptive therapy may also lead to the adynamic bone condition. The hallmark of adynamic bone is a loss of bone turnover, and a major clinical concern of adynamic bone is diminished bone quality and an increase in fracture risk. Our current study aims to investigate how bone quality changes with age in our previously established mouse model of adynamic bone. Young and old mice (4 months old and 16 months old, respectively) were used in this study. Col2.3Δtk (DTK) mice were treated with ganciclovir and pamidronate to create the adynamic bone condition. Bone quality was evaluated using established techniques including bone histomorphometry, microcomputed tomography, quantitative backscattered electron imaging, and biomechanical testing. Changes in mineral and matrix properties were examined by powder X-ray diffraction and Raman spectroscopy. Aging controls had a natural decline in bone formation and resorption with a corresponding deterioration in trabecular bone structure. Bone turnover was severely blunted at all ages in adynamic animals, which preserved trabecular bone loss normally associated with aging. However, the preservation of trabecular bone mass and structure in old adynamic mice did not rescue deterioration of bone mechanical properties. There was also a decrease in cortical bone toughness in old adynamic mice that was accompanied by a more mature collagen matrix and longer bone crystals. Little is known about the effects of metabolic bone disease on bone fracture resistance. We observed an age-related decrease in bone toughness that was worsened by the adynamic condition, and this decrease may be due to material level changes at the tissue level. Our mouse model may be useful in the investigation of the mechanisms involved in fractures occurring in elderly patients on antiresorptive therapy who have very low bone turnover. PMID:26332924

  5. The Role of Dextran Coatings on the Cytotoxicity Properties of Ceria Nanoparticles Toward Bone Cancer Cells

    Science.gov (United States)

    Yazici, Hilal; Alpaslan, Ece; Webster, Thomas J.

    2015-04-01

    Cerium oxide nanoparticles have demonstrated great potential as antioxidant and radioprotective agents for nanomedicine applications especially for cancer therapy. The surface chemistry of nanoparticles is an important property that has a significant effect on their performance in biological applications including cancer diagnosis, cancer treatment, and bacterial infection. Recently, various nanosized cerium oxide particles with different types of polymer coatings have been developed to improve aqueous solubility and allow for surface functionalization for distinct applications. In this study, the role of ceria nanoparticles coated with dextran on the cytotoxicity properties of bone cancer cells was shown. Specifically, 0.1 M and 0.01 M dextran-coated, bone cancer cells was observed for the 0.01 M dextran coating after 3 days compared with the 0.1 M dextran coating. These results indicated that surface dextran functionalization had a positive impact on the cytotoxicity of cerium oxide nanoparticles against osteosarcoma cells.

  6. Preparation and biological properties of a novel composite scaffold of nano-hydroxyapatite/chitosan/carboxymethyl cellulose for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Chengdong Xiong

    2009-07-01

    Full Text Available Abstract In this study, we report the physico-chemical and biological properties of a novel biodegradable composite scaffold made of nano-hydroxyapatite and natural derived polymers of chitosan and carboxymethyl cellulose, namely, n-HA/CS/CMC, which was prepared by freeze-drying method. The physico-chemical properties of n-HA/CS/CMC scaffold were tested by infrared absorption spectra (IR, transmission electron microscope(TEM, scanning electron microscope(SEM, universal material testing machine and phosphate buffer solution (PBS soaking experiment. Besides, the biological properties were evaluated by MG63 cells and Mesenchymal stem cells (MSCs culture experiment in vitro and a short period implantation study in vivo. The results show that the composite scaffold is mainly formed through the ionic crossing-linking of the two polyions between CS and CMC, and n-HA is incorporated into the polyelectrolyte matrix of CS-CMC without agglomeration, which endows the scaffold with good physico-chemical properties such as highly interconnected porous structure, high compressive strength and good structural stability and degradation. More important, the results of cells attached, proliferated on the scaffold indicate that the scaffold is non-toxic and has good cell biocompatibility, and the results of implantation experiment in vivo further confirm that the scaffold has good tissue biocompatibility. All the above results suggest that the novel degradable n-HA/CS/CMC composite scaffold has a great potential to be used as bone tissue engineering material.

  7. Fabrication method, structure, mechanical, and biological properties of decellularized extracellular matrix for replacement of wide bone tissue defects.

    Science.gov (United States)

    Anisimova, N Y; Kiselevsky, M V; Sukhorukova, I V; Shvindina, N V; Shtansky, D V

    2015-09-01

    The present paper was focused on the development of a new method of decellularized extracellular matrix (DECM) fabrication via a chemical treatment of a native bone tissue. Particular attention was paid to the influence of chemical treatment on the mechanical properties of native bones, sterility, and biological performance in vivo using the syngeneic heterotopic and orthotopic implantation models. The obtained data indicated that after a chemical decellularization treatment in 4% aqueous sodium chlorite, no noticeable signs of the erosion of compact cortical bone surface or destruction of trabeculae of spongy bone in spinal channel were observed. The histological studies showed that the chemical treatment resulted in the decellularization of both bone and cartilage tissues. The DECM samples demonstrated no signs of chemical and biological degradation in vivo. Thorough structural characterization revealed that after decellularization, the mineral frame retained its integrity with the organic phase; however clotting and destruction of organic molecules and fibers were observed. FTIR studies revealed several structural changes associated with the destruction of organic molecules, although all organic components typical of intact bone were preserved. The decellularization-induced structural changes in the collagen constituent resulted changed the deformation under compression mechanism: from the major fracture by crack propagation throughout the sample to the predominantly brittle fracture. Although the mechanical properties of radius bones subjected to decellularization were observed to degrade, the mechanical properties of ulna bones in compression and humerus bones in bending remained unchanged. The compressive strength of both the intact and decellularized ulna bones was 125-130 MPa and the flexural strength of humerus bones was 156 and 145 MPa for the intact and decellularized samples, respectively. These results open new avenues for the use of DECM samples as

  8. Development of Visco-elasto-plastic Material Model for Human Trabecular Bone using Nanoindentation

    Czech Academy of Sciences Publication Activity Database

    Zlámal, Petr; Kytýř, Daniel; Jiroušek, Ondřej; Němeček, J.

    Chemnitz : Chemnitz University of Technology, 2011 - (Stockmann, M.; Kretzschmar, J.), s. 127-128 ISBN 978-3-941003-34-7. [Youth Symposium on Experimental Solid Mechanics /10./. Chemnitz (DE), 25.05.2011-28.05.2011] R&D Projects: GA ČR(CZ) GAP105/10/2305 Institutional research plan: CEZ:AV0Z20710524 Keywords : trabecular bone * material model * nanoindentation Subject RIV: FI - Traumatology, Orthopedics http://www.tu-chemnitz.de/mb/FestKoerpMech/YSESM/proceedings.php

  9. Bone as a composite material: the role of osteons as barriers to crack growth in compact bone.

    OpenAIRE

    O'Brien, Fergal J.; Taylor, David; Lee, T Clive

    2007-01-01

    This article summarises a number of studies in the area of bone microdamage which were carried out in our laboratory over the past 5 years. A technique was developed to label microcracks during mechanical testing. Fluorescent chelating agents were applied at intervals to bone specimens fatigue tested in cyclic compression until failure occurred. Microcrack densities were measured and microcrack length at the time of encountering the cement line surrounding an osteon was also recorded. Microcr...

  10. Mechanical and thermal properties of castor oil polyurethane bone cement after gamma irradiation

    International Nuclear Information System (INIS)

    Polyurethanes from castor oil are being employed as bone cement in medical applications. In this work the thermal and mechanical properties of gamma irradiated polyurethanes derivative from castor oil were investigated by instrumented indentation, thermogravimetry and scanning electron microscopy. A slightly increase in hardness is observed only for doses as high as 100 kGy. Thermal analysis indicates stability at human body temperature. The glass transition temperature has small changes after gamma irradiation. (author)

  11. The influence of different loads on the remodeling process of a bone and bioresorbable material mixture with voids

    Science.gov (United States)

    Giorgio, Ivan; Andreaus, Ugo; Madeo, Angela

    2016-03-01

    A model of a mixture of bone tissue and bioresorbable material with voids was used to numerically analyze the physiological balance between the processes of bone growth and resorption and artificial material resorption in a plate-like sample. The adopted model was derived from a theory for the behavior of porous solids in which the matrix material is linearly elastic and the interstices are void of material. The specimen—constituted by a region of bone living tissue and one of bioresorbable material—was acted by different in-plane loading conditions, namely pure bending and shear. Ranges of load magnitudes were identified within which physiological states become possible. Furthermore, the consequences of applying different loading conditions are examined at the end of the remodeling process. In particular, maximum value of bone and material mass densities, and extensions of the zones where bone is reconstructed were identified and compared in the two different load conditions. From the practical view point, during surgery planning and later rehabilitation, some choice of the following parameters is given: porosity of the graft, material characteristics of the graft, and adjustment of initial mixture tissue/bioresorbable material and later, during healing and remodeling, optimal loading conditions.

  12. Protein growth factors loaded highly porous chitosan scaffold: A comparison of bone healing properties

    Energy Technology Data Exchange (ETDEWEB)

    Nandi, Samit K., E-mail: samitnandi1967@gmail.com [Department of Veterinary Surgery and Radiology, West Bengal University of Animal and Fishery Sciences, Kolkata (India); Kundu, Biswanath, E-mail: biswa_kundu@rediffmail.com [Bioceramics and Coating Division, CSIR—Central Glass and Ceramic Research Institute, Kolkata (India); Basu, Debabrata [Bioceramics and Coating Division, CSIR—Central Glass and Ceramic Research Institute, Kolkata (India)

    2013-04-01

    Present study aimed to investigate and compare effectiveness of porous chitosan alone and in combination with insulin like growth factor-1 (IGF-1) and bone morphogenetic protein-2 (BMP-2) in bone healing. Highly porous (85 ± 2%) with wide distribution of macroporous (70–900 μm) chitosan scaffolds were fabricated as bone substitutes by employing a simple liquid hardening method using 2% (w/v) chitosan suspension. IGF-1 and BMP-2 were infiltrated using vacuum infiltration with freeze drying method. Adsorption efficiency was found to be 87 ± 2 and 90 ± 2% for BMP-2 and IGF-1 respectively. After thorough material characterization (pore details, FTIR and SEM), samples were used for subsequent in vivo animal trial. Eighteen rabbit models were used to evaluate and compare control (chitosan) (group A), chitosan with IGF-1 (group B) and chitosan with BMP-2 (group C) in the repair of critical size bone defect in tibia. Radiologically, there was evidence of radiodensity in defect area from 60th day (initiated on 30th day) in groups B and C as compared to group A and attaining nearly bony density in most of the part at day 90. Histological results depicted well developed osteoblastic proliferation around haversian canal along with proliferating fibroblast, vascularization and reticular network which was more pronounced in group B followed by groups C and A. Fluorochrome labeling and SEM studies in all groups showed similar outcome. Hence, porous chitosan alone and in combination with growth factors (GFs) can be successfully used for bone defect healing with slight advantage of IGF-1 in chitosan samples. - Highlights: ► Fabrication and characterization of porous chitosan with or without IGF-1 and BMP-2 ► Highly porous growth factor loaded chitosan studied in animal subjects for 3 months ► Parameters studied: histopathology, radiology and fluorochrome labeling ► IGF-1 loaded porous chitosan found to be very effective for bone defect healing.

  13. Protein growth factors loaded highly porous chitosan scaffold: A comparison of bone healing properties

    International Nuclear Information System (INIS)

    Present study aimed to investigate and compare effectiveness of porous chitosan alone and in combination with insulin like growth factor-1 (IGF-1) and bone morphogenetic protein-2 (BMP-2) in bone healing. Highly porous (85 ± 2%) with wide distribution of macroporous (70–900 μm) chitosan scaffolds were fabricated as bone substitutes by employing a simple liquid hardening method using 2% (w/v) chitosan suspension. IGF-1 and BMP-2 were infiltrated using vacuum infiltration with freeze drying method. Adsorption efficiency was found to be 87 ± 2 and 90 ± 2% for BMP-2 and IGF-1 respectively. After thorough material characterization (pore details, FTIR and SEM), samples were used for subsequent in vivo animal trial. Eighteen rabbit models were used to evaluate and compare control (chitosan) (group A), chitosan with IGF-1 (group B) and chitosan with BMP-2 (group C) in the repair of critical size bone defect in tibia. Radiologically, there was evidence of radiodensity in defect area from 60th day (initiated on 30th day) in groups B and C as compared to group A and attaining nearly bony density in most of the part at day 90. Histological results depicted well developed osteoblastic proliferation around haversian canal along with proliferating fibroblast, vascularization and reticular network which was more pronounced in group B followed by groups C and A. Fluorochrome labeling and SEM studies in all groups showed similar outcome. Hence, porous chitosan alone and in combination with growth factors (GFs) can be successfully used for bone defect healing with slight advantage of IGF-1 in chitosan samples. - Highlights: ► Fabrication and characterization of porous chitosan with or without IGF-1 and BMP-2 ► Highly porous growth factor loaded chitosan studied in animal subjects for 3 months ► Parameters studied: histopathology, radiology and fluorochrome labeling ► IGF-1 loaded porous chitosan found to be very effective for bone defect healing

  14. Effects of spaceflight and Insulin-like Growth Factor-1 on rat bone properties

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, T.A.; Ayers, R.A.; Spetzler, M.L.; Simske, S.J. [BioServe Space Technologies University of Colorado Boulder, Colorado80309-0429 (United States); Zimmerman, R.J. [Chiron Corporation 4560 Horton Street Emeryville, California94608-2916 (United States)

    1997-01-01

    Spaceflight induces bone degradation which is analogous to an accelerated onset of osteoporosis in humans (Tilton {ital et al.}, 1980). In rats, decreased bone formation is indicative of reduced osteoblast activity (Morey and Baylink, 1978). Chiron Corporation (Emeryville, CA) is interested in using the microgravity environment of low-Earth-orbit to test its therapeutic drug, Insulin-like Growth Factor-1 (IGF-1). This pharmaceutic is known to promote osteoblast activity (Schmid {ital et al.}, 1984) and therefore may encourage bone growth in rats. Chiron sponsored the Immune.3 payload on STS-73 (May 19{endash}29, 1996) through its Center for Space Commercialization (CSC) partner BioServe Space Technologies (University of Colorado and Kansas State University) to investigate the effects of IGF-1 on mitigating the skeletal degradation that affects rats and humans during spaceflight. Twelve rats were flown for 10 days using two Animal Enclosure Modules (AEMs) provided by NASA Ames Research Center. Of the twelve, six received 1.4 mg/day of IGF-1; the other six saline. Sixteen vivarium ground controls received the same treatment on a one day delay. Rat femora and tibiae were examined for bone mineral density via DXA scan. Femora and humeri were measured for physical and compositional properties, as well as mechanically tested in three point flexure. Quantitative histomorphometric examination of tibiae, humeri, fibulae, ribs and cranial bone; and microhardness testing on tibiae and humeri are currently in progress. Flight humeri and vivarium femora were significantly larger than their counterparts; however, significant differences in mechanical properties and mineral density were not concurrent to these mass changes. {copyright} {ital 1997 American Institute of Physics.}

  15. Effects of spaceflight and Insulin-like Growth Factor-1 on rat bone properties

    Science.gov (United States)

    Bateman, Ted A.; Ayers, Reed A.; Spetzler, Michael L.; Simske, Steven J.; Zimmerman, Robert J.

    1997-01-01

    Spaceflight induces bone degradation which is analogous to an accelerated onset of osteoporosis in humans (Tilton et al., 1980). In rats, decreased bone formation is indicative of reduced osteoblast activity (Morey and Baylink, 1978). Chiron Corporation (Emeryville, CA) is interested in using the microgravity environment of low-Earth-orbit to test its therapeutic drug, Insulin-like Growth Factor-1 (IGF-1). This pharmaceutic is known to promote osteoblast activity (Schmid et al., 1984) and therefore may encourage bone growth in rats. Chiron sponsored the Immune.3 payload on STS-73 (May 19-29, 1996) through its Center for Space Commercialization (CSC) partner BioServe Space Technologies (University of Colorado and Kansas State University) to investigate the effects of IGF-1 on mitigating the skeletal degradation that affects rats and humans during spaceflight. Twelve rats were flown for 10 days using two Animal Enclosure Modules (AEMs) provided by NASA Ames Research Center. Of the twelve, six received 1.4 mg/day of IGF-1; the other six saline. Sixteen vivarium ground controls received the same treatment on a one day delay. Rat femora and tibiae were examined for bone mineral density via DXA scan. Femora and humeri were measured for physical and compositional properties, as well as mechanically tested in three point flexure. Quantitative histomorphometric examination of tibiae, humeri, fibulae, ribs and cranial bone; and microhardness testing on tibiae and humeri are currently in progress. Flight humeri and vivarium femora were significantly larger than their counterparts; however, significant differences in mechanical properties and mineral density were not concurrent to these mass changes.

  16. Apparent properties of trabecular bone determined using voxel-based FE models and nanoindentation

    Czech Academy of Sciences Publication Activity Database

    Jiroušek, Ondřej; Vavřík, Daniel; Jakubek, J.; Dammer, J.; Němeček, J.

    Prague : Faculty of Transportation Sciences CTU, 2008 - (Jírová, J.), s. 1-2 ISBN 978-80-86246-34-5. [XI. Bilateral Czech/German Symposium. Liblice (CZ), 28.05.2008-30.05.2008] R&D Projects: GA ČR(CZ) GP103/07/P483 Institutional research plan: CEZ:AV0Z20710524 Keywords : trabecular bone * nanoidentation * micro computed tomography Subject RIV: JJ - Other Materials

  17. Absorption properties of waste matrix materials

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, J.B. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1997-06-01

    This paper very briefly discusses the need for studies of the limiting critical concentration of radioactive waste matrix materials. Calculated limiting critical concentration values for some common waste materials are listed. However, for systems containing large quantities of waste materials, differences up to 10% in calculated k{sub eff} values are obtained by changing cross section data sets. Therefore, experimental results are needed to compare with calculation results for resolving these differences and establishing realistic biases.

  18. Multi-scale modeling in heterogeneous material properties : An application to porous piezoelectric material

    OpenAIRE

    Asai, Mitsuteru

    2012-01-01

    Many engineering problems involve different scale in space or time. The main interest for engineering designer is to find an optimum macroscopic response of structure, although the macroscopic response is strongly dependent on the microscopic material properties. The material itself has an individual microstructure, and the optimum material is fabricated by controlling the microstructure. Usually, the macroscopic material properties are measured by the experimental material tests. The asympto...

  19. Preparation of gelatin based porous biocomposite for bone tissue engineering and evaluation of gamma irradiation effect on its properties

    International Nuclear Information System (INIS)

    Biodegradable porous hybrid polymer composites were prepared by using gelatin as base polymer matrix, β-tricalcium phosphate (TCP) and calcium sulfate (CS) as cementing materials, chitosan as an antimicrobial agent, and glutaraldehyde and polyethylene glycol (PEG) as crosslinkers at different mass ratios. Thereafter, the composites were subjected to γ-radiation sterilization. The structure and properties of these composite scaffolds were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), mechanical properties testing (compressive, bending, tensile and impact), thermogravimetry/differential thermal analysis (TG/DTA), and physical stability test in simulated body fluid (SBF). We found that TCP rich composites showed enhanced mechanical properties among all the crosslinked composites. γ-Radiation sterilization triggered further cross linking in polymer matrix resulting a decrease in pore size of the composites and an increase in pore wall thickness with improved mechanical and thermal properties. The chemically crosslinked composite with 40% TCP followed by γ-radiation sterilization showed the smallest pore size distribution with a mean pore diameter of 159.22 μm, which falls in the range of 100–350 μm — known to be suitable for osteoconduction. Considering its improved mechanical and thermal properties along with osteoconduction ability without cytotoxicity, we propose this biocomposite as a viable candidate for bone tissue engineering. - Highlights: • Composite scaffolds were prepared from biopolymers (gelatin and chitosan). • β-TCP and CS were used as bioactive cementing materials at different ratios. • γ-Sterilization improved the mechanical properties of the biocomposites. • γ-Sterilization reduced the cytotoxicity and induced high antimicrobial properties. • Composite having 40% TCP has the proper pore size distribution for osteoconduction

  20. Preparation of gelatin based porous biocomposite for bone tissue engineering and evaluation of gamma irradiation effect on its properties

    Energy Technology Data Exchange (ETDEWEB)

    Islam, Md. Minhajul [Department of Applied Chemistry and Chemical Engineering, Faculty of Engineering and Technology, University of Dhaka, Dhaka 1000 (Bangladesh); Khan, Mubarak A. [Institute of Radiation and Polymer Technology (IRPT), Atomic Energy Research Establishment (AERE), P. O. Box No. 3787, Dhaka 1000 (Bangladesh); Rahman, Mohammed Mizanur, E-mail: mizanur.rahman@du.ac.bd [Department of Applied Chemistry and Chemical Engineering, Faculty of Engineering and Technology, University of Dhaka, Dhaka 1000 (Bangladesh)

    2015-04-01

    Biodegradable porous hybrid polymer composites were prepared by using gelatin as base polymer matrix, β-tricalcium phosphate (TCP) and calcium sulfate (CS) as cementing materials, chitosan as an antimicrobial agent, and glutaraldehyde and polyethylene glycol (PEG) as crosslinkers at different mass ratios. Thereafter, the composites were subjected to γ-radiation sterilization. The structure and properties of these composite scaffolds were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), mechanical properties testing (compressive, bending, tensile and impact), thermogravimetry/differential thermal analysis (TG/DTA), and physical stability test in simulated body fluid (SBF). We found that TCP rich composites showed enhanced mechanical properties among all the crosslinked composites. γ-Radiation sterilization triggered further cross linking in polymer matrix resulting a decrease in pore size of the composites and an increase in pore wall thickness with improved mechanical and thermal properties. The chemically crosslinked composite with 40% TCP followed by γ-radiation sterilization showed the smallest pore size distribution with a mean pore diameter of 159.22 μm, which falls in the range of 100–350 μm — known to be suitable for osteoconduction. Considering its improved mechanical and thermal properties along with osteoconduction ability without cytotoxicity, we propose this biocomposite as a viable candidate for bone tissue engineering. - Highlights: • Composite scaffolds were prepared from biopolymers (gelatin and chitosan). • β-TCP and CS were used as bioactive cementing materials at different ratios. • γ-Sterilization improved the mechanical properties of the biocomposites. • γ-Sterilization reduced the cytotoxicity and induced high antimicrobial properties. • Composite having 40% TCP has the proper pore size distribution for osteoconduction.

  1. Effect of ZrO2 addition on the mechanical properties of porous TiO2 bone scaffolds

    International Nuclear Information System (INIS)

    This study aimed at the investigation of the effect of zirconium dioxide (ZrO2) addition on the mechanical properties of titanium dioxide (TiO2) bone scaffolds. The highly biocompatible TiO2 has been identified as a promising material for bone scaffolds, whereas the more bioinert ZrO2 is known for its excellent mechanical properties. Ultra-porous TiO2 scaffolds (> 89% porosity) were produced using polymer sponge replication with 0–40 wt.% of the TiO2 raw material substituted with ZrO2. Microstructure, chemical composition, and pore architectural features of the prepared ceramic foams were characterised and related to their mechanical strength. Addition of 1 wt.% of ZrO2 led to 16% increase in the mean compressive strength without significant changes in the pore architectural parameters of TiO2 scaffolds. Further ZrO2 additions resulted in reduction of compressive strength in comparison to containing no ZrO2. The appearance of zirconium titanate (ZrTiO4) phase was found to hinder the densification of the ceramic material during sintering resulting in poor intergranular connections and thus significantly reducing the compressive strength of the highly porous ceramic foam scaffolds. - Highlights: ► Open porous scaffold with porosity in the range of 89.0 to 92.8% produced. ► Adding 1 wt.% of ZrO2 led to 16% increase in strength without changing porosity. ► Further ZrO2 additions resulted in reduced compressive strength versus no ZrO2. ► Presence of zirconium titanate (ZrTiO4) phase found to hinder the densification. ► Appearance of ZrTiO4 resulted in poor intergranular connections.

  2. Metallurgy and properties of plasma spray formed materials

    Science.gov (United States)

    Mckechnie, T. N.; Liaw, Y. K.; Zimmerman, F. R.; Poorman, R. M.

    1992-01-01

    Understanding the fundamental metallurgy of vacuum plasma spray formed materials is the key to enhancing and developing full material properties. Investigations have shown that the microstructure of plasma sprayed materials must evolve from a powder splat morphology to a recrystallized grain structure to assure high strength and ductility. A fully, or near fully, dense material that exhibits a powder splat morphology will perform as a brittle material compared to a recrystallized grain structure for the same amount of porosity. Metallurgy and material properties of nickel, iron, and copper base alloys will be presented and correlated to microstructure.

  3. Efficacy of Dual Energy X-ray Absorptiometry for Evaluation of Biomechanical Properties: Bone Mineral Density and Actual Bone Strength

    OpenAIRE

    Seo, Sung Hwa; Lee, Joomi; Park, Il Hyung

    2014-01-01

    Introduction Bone mineral density (BMD) is an important index in diagnosis of osteoporosis and other metabolic bone diseases, prediction of fractures, and monitoring treatment. This study was to find a more feasible technique for prediction of osteoporotic fracture between dual energy X-ray absorptiometry (DXA) and quantitative computed tomography (QCT) and to reveal the actual change of bone strength when BMD was changed. Methods Ten of these 20 specimens were used as the demineralized group...

  4. Preparation of gelatin based porous biocomposite for bone tissue engineering and evaluation of gamma irradiation effect on its properties.

    Science.gov (United States)

    Islam, Md Minhajul; Khan, Mubarak A; Rahman, Mohammed Mizanur

    2015-04-01

    Biodegradable porous hybrid polymer composites were prepared by using gelatin as base polymer matrix, β-tricalcium phosphate (TCP) and calcium sulfate (CS) as cementing materials, chitosan as an antimicrobial agent, and glutaraldehyde and polyethylene glycol (PEG) as crosslinkers at different mass ratios. Thereafter, the composites were subjected to γ-radiation sterilization. The structure and properties of these composite scaffolds were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), mechanical properties testing (compressive, bending, tensile and impact), thermogravimetry/differential thermal analysis (TG/DTA), and physical stability test in simulated body fluid (SBF). We found that TCP rich composites showed enhanced mechanical properties among all the crosslinked composites. γ-Radiation sterilization triggered further cross linking in polymer matrix resulting a decrease in pore size of the composites and an increase in pore wall thickness with improved mechanical and thermal properties. The chemically crosslinked composite with 40% TCP followed by γ-radiation sterilization showed the smallest pore size distribution with a mean pore diameter of 159.22μm, which falls in the range of 100-350μm - known to be suitable for osteoconduction. Considering its improved mechanical and thermal properties along with osteoconduction ability without cytotoxicity, we propose this biocomposite as a viable candidate for bone tissue engineering. PMID:25686994

  5. Bioactivity and bone healing properties of biomimetic porous composite scaffold: in vitro and in vivo studies.

    Science.gov (United States)

    Veronesi, Francesca; Giavaresi, Gianluca; Guarino, Vincenzo; Raucci, Maria Grazia; Sandri, Monica; Tampieri, Anna; Ambrosio, Luigi; Fini, Milena

    2015-09-01

    Tissue engineering (TE) represents a valid alternative to traditional surgical therapies for the management of bone defects that do not regenerate spontaneously. Scaffolds, one of the most important component of TE strategy, should be biocompatible, bioactive, osteoconductive, and osteoinductive. The aim of this study was to evaluate the biological properties and bone regeneration ability of a porous poly(ɛ-caprolactone) (PCL) scaffold, incorporating MgCO3 -doped hydroxyapatite particles, uncoated (PCL_MgCHA) or coated by apatite-like crystals via biomimetic treatment (PCL_MgCHAB). It was observed that both scaffolds are not cytotoxic and, even if cell viability was similar on both scaffolds, PCL_MgCHAB showed higher alkaline phosphatase and collagen I (COLL I) production at day 7. PCL_MgCHA induced more tumor necrosis factor-α release than PCL_MgCHAB, while osteocalcin was produced less by both scaffolds up to 7 days and no significant differences were observed for transforming growth factor-β synthesis. The percentage of new bone trabeculae growth in wide defects carried out in rabbit femoral distal epiphyses was significantly higher in PCL_MgCHAB in comparison with PCL_MgCHA at 4 weeks and even more at 12 weeks after implantation. This study highlighted the role of a biomimetic composite scaffold in bone regeneration and lays the foundations for its future employment in the clinical practice. PMID:25689266

  6. Surface modification of fiber reinforced polymer composites and their attachment to bone simulating material.

    Science.gov (United States)

    Hautamäki, M P; Puska, M; Aho, A J; Kopperud, H M; Vallittu, P K

    2013-05-01

    The purpose of this study was to investigate the effect of fiber orientation of a fiber-reinforced composite (FRC) made of poly-methyl-methacrylate (PMMA) and E-glass to the surface fabrication process by solvent dissolution. Intention of the dissolution process was to expose the fibers and create a macroporous surface onto the FRC to enhance bone bonding of the material. The effect of dissolution and fiber direction to the bone bonding capability of the FRC material was also tested. Three groups of FRC specimens (n = 18/group) were made of PMMA and E-glass fiber reinforcement: (a) group with continuous fibers parallel to the surface of the specimen, (b) continuous fibers oriented perpendicularly to the surface, (c) randomly oriented short (discontinuous) fibers. Fourth specimen group (n = 18) made of plain PMMA served as controls. The specimens were subjected to a solvent treatment by tetrahydrofuran (THF) of either 5, 15 or 30 min of time (n = 6/time point), and the advancement of the dissolution (front) was measured. The solvent treatment also exposed the fibers and created a surface roughness on to the specimens. The solvent treated specimens were embedded into plaster of Paris to simulate bone bonding by mechanical locking and a pull-out test was undertaken to determine the strength of the attachment. All the FRC specimens dissolved as function of time, as the control group showed no marked dissolution during the study period. The specimens with fibers along the direction of long axis of specimen began to dissolve significantly faster than specimens in other groups, but the test specimens with randomly oriented short fibers showed the greatest depth of dissolution after 30 min. The pull-out test showed that the PMMA specimens with fibers were retained better by the plaster of Paris than specimens without fibers. However, direction of the fibers considerably influenced the force of attachment. The fiber reinforcement increases significantly the

  7. Viscoelastic properties of bovine articular cartilage attached to subchondral bone at high frequencies

    Directory of Open Access Journals (Sweden)

    Shepherd Duncan ET

    2009-06-01

    Full Text Available Abstract Background Articular cartilage is a viscoelastic material, but its exact behaviour under the full range of physiological loading frequencies is unknown. The objective of this study was to measure the viscoelastic properties of bovine articular cartilage at loading frequencies of up to 92 Hz. Methods Intact tibial plateau cartilage, attached to subchondral bone, was investigated by dynamic mechanical analysis (DMA. A sinusoidally varying compressive force of between 16 N and 36 N, at frequencies from 1 Hz to 92 Hz, was applied to the cartilage surface by a flat indenter. The storage modulus, loss modulus and phase angle (between the applied force and the deformation induced were determined. Results The storage modulus, E', increased with increasing frequency, but at higher frequencies it tended towards a constant value. Its dependence on frequency, f, could be represented by, E' = Aloge (f + B where A = 2.5 ± 0.6 MPa and B = 50.1 ± 12.5 MPa (mean ± standard error. The values of the loss modulus (4.8 ± 1.0 MPa mean ± standard deviation were much less than the values of storage modulus and showed no dependence on frequency. The phase angle was found to be non-zero for all frequencies tested (4.9 ± 0.6°. Conclusion Articular cartilage is viscoelastic throughout the full range of frequencies investigated. The behaviour has implications for mechanical damage to articular cartilage and the onset of osteoarthritis. Storage modulus increases with frequency, until the plateau region is reached, and has a higher value than loss modulus. Furthermore, loss modulus does not increase with loading frequency. This means that more energy is stored by the tissue than is dissipated and that this effect is greater at higher frequencies. The main mechanism for this excess energy to be dissipated is by the formation of cracks.

  8. New elastoplastic materials with performance properties

    Directory of Open Access Journals (Sweden)

    Sanda VISAN,

    2009-06-01

    Full Text Available The fabrication of high performance materials using EPDM rubber and polyethylene mixtures with a low cost, nonpolluting and minimum investment technology is studied. These new materials can be used for obtaining a lot of goods for the economy, sport and private life.

  9. Material rhetoric: spreading stones and showing bones in the study of prehistory.

    Science.gov (United States)

    Van Reybrouck, David; de Bont, Raf; Rock, Jan

    2009-06-01

    Since the linguistic turn, the role of rhetoric in the circulation and the popular representation of knowledge has been widely accepted in science studies. This article aims to analyze not a textual form of scientific rhetoric, but the crucial role of materiality in scientific debates. It introduces the concept of material rhetoric to understand the promotional regimes in which material objects play an essential argumentative role. It analyzes the phenomenon by looking at two students of prehistory from nineteenth-century Belgium. In the study of human prehistory and evolution, material data are either fairly abundant stone tools or very scarce fossil bones. These two types of material data stand for two different strategies in material rhetoric. In this article, the first strategy is exemplified by Aimé Rutot, who gathered great masses of eoliths (crudely chipped stones which he believed to be prehistoric tools). The second strategy is typified by the example of Julien Fraipont, who based his scientific career on only two Neanderthal skeletons. Rutot sent his "artifacts" to a very wide audience, while Fraipont showed his skeletons to only a few selected scholars. Unlike Rutot, however, Fraipont was able to monitor his audience's interpretation of the finds by means of personal contacts. What an archaeologist gains in reach, he or she apparently loses in control. In this article we argue that only those scholars who find the right balance between the extremes of reach and control will prove to be successful. PMID:19827370

  10. Applicability of cranial models in urethane resin and foam as a substitute for bone: are synthetic materials reliable?

    Science.gov (United States)

    Muccino, Enrico; Porta, Davide; Magli, Francesca; Cigada, Alfredo; Sala, Remo; Gibelli, Daniele; Cattaneo, Cristina

    2013-09-01

    As literature is poor in functional synthetic cranial models, in this study, synthetic handmade models of cranial vaults were produced in two different materials (a urethane resin and a self-hardening foam), from multiple bone specimens (eight original cranial vaults: four human and four swine), in order to test their resemblance to bone structure in behavior, during fracture formation. All the vaults were mechanically tested with a 2-kg impact weight and filmed with a high-speed camera. Fracture patterns were homogeneous in all swine vaults and heterogeneous in human vaults, with resin fractures more similar to bone fractures. Mean fracture latency time extrapolated by videos were of 0.75 msec (bone), 1.5 msec (resin), 5.12 msec (foam) for human vaults and of 0.625 msec (bone), 1.87 msec (resin), 3.75 msec (foam) for swine vaults. These data showed that resin models are more similar to bone than foam reproductions, but that synthetic material may behave quite differently from bone as concerns fracture latency times. PMID:23865474

  11. Reference point indentation is insufficient for detecting alterations in traditional mechanical properties of bone under common experimental conditions.

    Science.gov (United States)

    Krege, John B; Aref, Mohammad W; McNerny, Erin; Wallace, Joseph M; Organ, Jason M; Allen, Matthew R

    2016-06-01

    Reference point indentation (RPI) was developed as a novel method to assess mechanical properties of bone in vivo, yet it remains unclear what aspects of bone dictate changes/differences in RPI-based parameters. The main RPI parameter, indentation distance increase (IDI), has been proposed to be inversely related to the ability of bone to form/tolerate damage. The goal of this work was to explore the relationshipre-intervention RPI measurebetween RPI parameters and traditional mechanical properties under varying experimental conditions (drying and ashing bones to increase brittleness, demineralizing bones and soaking in raloxifene to decrease brittleness). Beams were machined from cadaveric bone, pre-tested with RPI, subjected to experimental manipulation, post-tested with RPI, and then subjected to four-point bending to failure. Drying and ashing significantly reduced RPI's IDI, as well as ultimate load (UL), and energy absorption measured from bending tests. Demineralization increased IDI with minimal change to bending properties. Ex vivo soaking in raloxifene had no effect on IDI but tended to enhance post-yield behavior at the structural level. These data challenge the paradigm of an inverse relationship between IDI and bone toughness, both through correlation analyses and in the individual experiments where divergent patterns of altered IDI and mechanical properties were noted. Based on these results, we conclude that RPI measurements alone, as compared to bending tests, are insufficient to reach conclusions regarding mechanical properties of bone. This proves problematic for the potential clinical use of RPI measurements in determining fracture risk for a single patient, as it is not currently clear that there is an IDI, or even a trend of IDI, that can determine clinically relevant changes in tissue properties that may contribute to whole bone fracture resistance. PMID:27072518

  12. Nanocomposites and bone regeneration

    Science.gov (United States)

    James, Roshan; Deng, Meng; Laurencin, Cato T.; Kumbar, Sangamesh G.

    2011-12-01

    This manuscript focuses on bone repair/regeneration using tissue engineering strategies, and highlights nanobiotechnology developments leading to novel nanocomposite systems. About 6.5 million fractures occur annually in USA, and about 550,000 of these individual cases required the application of a bone graft. Autogenous and allogenous bone have been most widely used for bone graft based therapies; however, there are significant problems such as donor shortage and risk of infection. Alternatives using synthetic and natural biomaterials have been developed, and some are commercially available for clinical applications requiring bone grafts. However, it remains a great challenge to design an ideal synthetic graft that very closely mimics the bone tissue structurally, and can modulate the desired function in osteoblast and progenitor cell populations. Nanobiomaterials, specifically nanocomposites composed of hydroxyapatite (HA) and/or collagen are extremely promising graft substitutes. The biocomposites can be fabricated to mimic the material composition of native bone tissue, and additionally, when using nano-HA (reduced grain size), one mimics the structural arrangement of native bone. A good understanding of bone biology and structure is critical to development of bone mimicking graft substitutes. HA and collagen exhibit excellent osteoconductive properties which can further modulate the regenerative/healing process following fracture injury. Combining with other polymeric biomaterials will reinforce the mechanical properties thus making the novel nano-HA based composites comparable to human bone. We report on recent studies using nanocomposites that have been fabricated as particles and nanofibers for regeneration of segmental bone defects. The research in nanocomposites, highlight a pivotal role in the future development of an ideal orthopaedic implant device, however further significant advancements are necessary to achieve clinical use.

  13. Calculation of material properties and ray tracing in transformation media.

    Science.gov (United States)

    Schurig, D; Pendry, J B; Smith, D R

    2006-10-16

    Complex and interesting electromagnetic behavior can be found in spaces with non-flat topology. When considering the properties of an electromagnetic medium under an arbitrary coordinate transformation an alternative interpretation presents itself. The transformed material property tensors may be interpreted as a different set of material properties in a flat, Cartesian space. We describe the calculation of these material properties for coordinate transformations that describe spaces with spherical or cylindrical holes in them. The resulting material properties can then implement invisibility cloaks in flat space. We also describe a method for performing geometric ray tracing in these materials which are both inhomogeneous and anisotropic in their electric permittivity and magnetic permeability. PMID:19529371

  14. "TPSX: Thermal Protection System Expert and Material Property Database"

    Science.gov (United States)

    Squire, Thomas H.; Milos, Frank S.; Rasky, Daniel J. (Technical Monitor)

    1997-01-01

    The Thermal Protection Branch at NASA Ames Research Center has developed a computer program for storing, organizing, and accessing information about thermal protection materials. The program, called Thermal Protection Systems Expert and Material Property Database, or TPSX, is available for the Microsoft Windows operating system. An "on-line" version is also accessible on the World Wide Web. TPSX is designed to be a high-quality source for TPS material properties presented in a convenient, easily accessible form for use by engineers and researchers in the field of high-speed vehicle design. Data can be displayed and printed in several formats. An information window displays a brief description of the material with properties at standard pressure and temperature. A spread sheet window displays complete, detailed property information. Properties which are a function of temperature and/or pressure can be displayed as graphs. In any display the data can be converted from English to SI units with the click of a button. Two material databases included with TPSX are: 1) materials used and/or developed by the Thermal Protection Branch at NASA Ames Research Center, and 2) a database compiled by NASA Johnson Space Center 9JSC). The Ames database contains over 60 advanced TPS materials including flexible blankets, rigid ceramic tiles, and ultra-high temperature ceramics. The JSC database contains over 130 insulative and structural materials. The Ames database is periodically updated and expanded as required to include newly developed materials and material property refinements.

  15. Superconductivity and magnetism: Materials properties and developments

    International Nuclear Information System (INIS)

    The 24th Risoe International Symposium on Materials Science focuses on development of new materials, devices and applications, as well as experimental and theoretical studies of novel and unexplained phenomena in superconductivity and magnetism, e.g. within high.Tc superconductivity, magnetic superconductors, MgB2, CMR materials, nanomagnetism and spin-tronics. The aim is to stimulate exchange of ideas and establish new collaborations between leading Danish and international scientists. The topics are addressed by presentations from 24 invited speakers and by 41 contributed papers. (ln)

  16. Superconductivity and magnetism: Materials properties and developments

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, N.H.; Bay, N.; Grivel, J.C. (eds.) [and others

    2003-07-01

    The 24th Risoe International Symposium on Materials Science focuses on development of new materials, devices and applications, as well as experimental and theoretical studies of novel and unexplained phenomena in superconductivity and magnetism, e.g. within high.T{sub c} superconductivity, magnetic superconductors, MgB{sub 2}, CMR materials, nanomagnetism and spin-tronics. The aim is to stimulate exchange of ideas and establish new collaborations between leading Danish and international scientists. The topics are addressed by presentations from 24 invited speakers and by 41 contributed papers. (ln)

  17. Textile materials for lightweight constructions technologies, methods, materials, properties

    CERN Document Server

    2016-01-01

    In this book, experts on textile technologies convey both general and specific informa­tion on various aspects of textile engineering, ready-made technologies, and textile chemistry. They describe the entire process chain from fiber materials to various yarn constructions, 2D and 3D textile constructions, preforms, and interface layer design. In addition, the authors introduce testing methods, shaping and simulation techniques for the characterization of and structural mechanics calculations on anisotropic, pliable high-performance textiles, including specific examples from the fields of fiber plastic composites, textile concrete, and textile membranes. Readers will also be familiarized with the potential offered by increasingly popular textile structures, for instance in the fields of composite technology, construction technology, security technology, and membrane technology. Textile materials and semi-finished products have widely varied potential characteristics, and are commonly used as essential element...

  18. Dynamic Alterations in Microarchitecture, Mineralization and Mechanical Property of Subchondral Bone in Rat Medial Meniscal Tear Model of Osteoarthritis

    Directory of Open Access Journals (Sweden)

    De-Gang Yu

    2015-01-01

    Full Text Available Background: The properties of subchondral bone influence the integrity of articular cartilage in the pathogenesis of osteoarthritis (OA. However, the characteristics of subchondral bone alterations remain unresolved. The present study aimed to observe the dynamic alterations in the microarchitecture, mineralization, and mechanical properties of subchondral bone during the progression of OA. Methods: A medial meniscal tear (MMT operation was performed in 128 adult Sprague Dawley rats to induce OA. At 2, 4, 8, and 12 weeks following the MMT operation, cartilage degeneration was evaluated using toluidine blue O staining, whereas changes in the microarchitecture indices and tissue mineral density (TMD, mineral-to-collagen ratio, and intrinsic mechanical properties of subchondral bone plates (BPs and trabecular bones (Tbs were measured using micro-computed tomography scanning, confocal Raman microspectroscopy and nanoindentation testing, respectively. Results: Cartilage degeneration occurred and worsened progressively from 2 to 12 weeks after OA induction. Microarchitecture analysis revealed that the subchondral bone shifted from bone resorption early (reduced trabecular BV/TV, trabecular number, connectivity density and trabecular thickness [Tb.Th], and increased trabecular spacing (Tb.Sp at 2 and 4 weeks to bone accretion late (increased BV/TV, Tb.Th and thickness of subchondral bone plate, and reduced Tb.Sp at 8 and 12 weeks. The TMD of both the BP and Tb displayed no significant changes at 2 and 4 weeks but decreased at 8 and 12 weeks. The mineral-to-collagen ratio showed a significant decrease from 4 weeks for the Tb and from 8 weeks for the BP after OA induction. Both the elastic modulus and hardness of the Tb showed a significant decrease from 4 weeks after OA induction. The BP showed a significant decrease in its elastic modulus from 8 weeks and its hardness from 4 weeks. Conclusion: The microarchitecture, mineralization and mechanical

  19. High-temperature superconductors: Fundamental properties and novel materials processing

    International Nuclear Information System (INIS)

    These proceedings are a peer refereed, published account of Symposium M, High Temperature Superconductor Fundamental Properties and Novel Materials Processing, held at the November 29--December 2, 1989 meeting of the Materials Research Society in Boston, Massachusetts. The papers are organized under the following headings: Theory, crystal chemistry and thermodynamic properties; Synthesis and characterization: bulk powder, Synthesis and characterization: films and superlattices; Microstructural studies, Critical currents and flux dynamics; Physical properties; Applications-oriented studies

  20. Effects of Zoledronate and Mechanical Loading during Simulated Weightlessness on Bone Structure and Mechanical Properties

    Science.gov (United States)

    Scott, R. T.; Nalavadi, M. O.; Shirazi-Fard, Y.; Castillo, A. B.; Alwood, J. S.

    2016-01-01

    Space flight modulates bone remodeling to favor bone resorption. Current countermeasures include an anti-resorptive drug class, bisphosphonates (BP), and high-force loading regimens. Does the combination of anti-resorptives and high-force exercise during weightlessness have negative effects on the mechanical and structural properties of bone? In this study, we implemented an integrated model to mimic mechanical strain of exercise via cyclical loading (CL) in mice treated with the BP Zoledronate (ZOL) combined with hindlimb unloading (HU). Our working hypothesis is that CL combined with ZOL in the HU model induces additive structural and mechanical changes. Thirty-two C57BL6 mice (male,16 weeks old, n8group) were exposed to 3 weeks of either HU or normal ambulation (NA). Cohorts of mice received one subcutaneous injection of ZOL (45gkg), or saline vehicle, prior to experiment. The right tibia was axially loaded in vivo, 60xday to 9N in compression, repeated 3xweek during HU. During the application of compression, secant stiffness (SEC), a linear estimate of slope of the force displacement curve from rest (0.5N) to max load (9.0N), was calculated for each cycle once per week. Ex vivo CT was conducted on all subjects. For ex vivo mechanical properties, non-CL left femurs underwent 3-point bending. In the proximal tibial metaphysis, HU decreased, CL increased, and ZOL increased the cancellous bone volume to total volume ratio by -26, +21, and +33, respectively. Similar trends held for trabecular thickness and number. Ex vivo left femur mechanical properties revealed HU decreased stiffness (-37),and ZOL mitigated the HU stiffness losses (+78). Data on the ex vivo Ultimate Force followed similar trends. After 3 weeks, HU decreased in vivo SEC (-16). The combination of CL+HU appeared additive in bone structure and mechanical properties. However, when HU + CL + ZOL were combined, ZOL had no additional effect (p0.05) on in vivo SEC. Structural data followed this trend with

  1. Effect of the sterilization process on physical and mechanical properties of the bonacryl bone cement

    International Nuclear Information System (INIS)

    The use of bone cements of poly(methyl methacrylate) (PMMA) to fix artificial prosthesis to the human body is a habitual method in orthopedic surgery. The hip and the knee joints have a very complex biomechanics and support high loads, for these reasons, acrylic bone cements have to comply with international standards in order to secure the biofuncionality and durability of the implant. In this work we report the effect of sterilization by ethylene oxide or gamma radiation on the BONACRYL Cuban cement. We determined how sterilization methods affect the molecular weight of the polymer as well as its quasi-static mechanical properties. The results demonstrated that the gamma radiation modifies the molecular weight of the PMMA although the compression and bending strength were not affected by the sterilization process applied. (authors)

  2. Adsorption Properties of Chalk Reservoir Materials

    DEFF Research Database (Denmark)

    Okhrimenko, Denis

    Understanding adsorption energetics and wetting properties of calcium carbonate surfaces is essential for developing remediation strategies for aquifers, improving oil recovery, minimising risk in CO2 storage and optimising industrial processes. This PhD was focussed on comparing the vapour....../gas adsorption properties of synthetic calcium carbonate phases (calcite, vaterite and aragonite) with chalk, which is composed of biogenic calcite (>98%). In combination with data from nanotechniques, the results demonstrate the complexity of chalk behavior and the role of nanoscale clay particles. The results...

  3. The processing and characterization of animal-derived bone to yield materials with biomedical applications. Part II: milled bone powders, reprecipitated hydroxyapatite and the potential uses of these materials.

    Science.gov (United States)

    Johnson, G S; Mucalo, M R; Lorier, M A; Gieland, U; Mucha, H

    2000-11-01

    Further studies on the processing and use of animal-bone-derived calcium phosphate materials in biomedical applications are presented. Bone powders sourced either from the direct crushing and milling of bovine, ovine and cervine bone or after being subjected to defatting and acid digestion/NaOH reprecipitation and sodium hypochlorite hydrogen peroxide treatment of animal bones were characterized using Fourier transform infra-red (FTIR) spectroscopy, 13C solid state magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy, atomic absorption (AA) and inductively coupled plasma (ICP) spectrometric techniques. Bone powders were trialled for their potential use as a substrate for phosphine coupling and enzyme immobilization as well as a feedstock powder for plasma spraying on titanium metal substrates. Results indicated that enzyme immobilization by phosphine coupling could be successfully achieved on milled cervine bone with the immobilized enzyme retaining some activity. It was found that the presence of impurities normally carried down with the processing of the bone materials (viz., fat and collagen) played an important role in influencing the adsorbency and reactivity of the powders. Plasma spraying studies using reprecipitated bovine-derived powders produced highly adherent coatings on titanium metal, the composition of which was mostly hydroxyapatite (Ca10(PO4)6(OH)2) with low levels of alpha-tricalcium phosphate (alpha-Ca3(PO4)2) and tetracalcium phosphate (Ca4P2O9) also detected. In general, animal derived calcium phosphate materials constitute a potentially cheaper source of calcium phosphate materials for biomedical applications and make use of a largely under-utilized resource from abattoir wastes. PMID:15348079

  4. Dielectric and electric properties of new chitosan-hydroxyapatite materials for biomedical application: Dielectric spectroscopy and corona treatment.

    Science.gov (United States)

    Petrov, Ivo; Kalinkevich, Oksana; Pogorielov, Maksym; Kalinkevich, Aleksei; Stanislavov, Aleksandr; Sklyar, Anatoly; Danilchenko, Sergei; Yovcheva, Temenuzhka

    2016-10-20

    Chitosan-hydroxyapatite composite materials were synthesized and the possibility to make their surface charged by corona discharge treatment has been evaluated. Dielectric and electric properties of the materials were studied by dielectric spectroscopy, including application of equivalent circuits method and computer simulations. Dielectric spectroscopy shows behavior of the materials quite different from that of both chitosan and HA alone. The obtained dielectric permittivity data are of particular interest in predicting the materials' behavior in electrostimulation after implantation. The ε values observed at physiological temperature in the frequency ranges applied are similar to ε data available for bone tissues. PMID:27474624

  5. Fundamental Material Properties Underlying Solid Oxide Electrochemistry

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Hansen, Karin Vels; Holtappels, Peter;

    2012-01-01

    electrochemical reactions take place at elevated temperatures from 300 and up to 1000 C. This has as consequence that the region around the threephase- boundary (TPB), where the electron conducting electrode, the electrolyte and the gas phase reactants meet, is the region where the electrochemical processes take...... place. The length of the TPB is a key factor even though the width and depth of the zone, in which the rate limiting reactions take place, may vary depending of the degree of the electrode materials ability to conduct both electrons and ions, i.e. the TPB zone volume depends on how good a mixed ionic...... materials in the TPB region. Also, segregations to the surfaces and interfaces of the electrode materials, which may affect the electrode reaction mechanism, are very dependent on the exact history of fabrication and operation. The positive effects of even small concentrations of nanoparticles in the...

  6. Magnetic Properties of Nanoparticles of Antiferromagnetic Materials

    DEFF Research Database (Denmark)

    Mørup, Steen; Frandsen, Cathrine; Bødker, Franz;

    2003-01-01

    The magnetic properties of antiferromagnetic nanoparticles have been studied by Mossbauer spectroscopy and neutron scattering. Temperature series of Mossbauer spectra of non-interacting, superparamagnetic hematite nanoparticles were fitted by use of the Blume-Tjon relaxation model. It has been fo...

  7. Mechanical properties of freeze-dried and irradiated bone chips, fascia lata and dura mater

    International Nuclear Information System (INIS)

    The comparison strengths of freeze-dried and irradiated bone chips such as three-dimensional cortex (3DC) and two-cortico cancellous (2CC) are investigated. The results show that the (3DC) exhibits a higher compression strength (1.2kN cm-2 in deep frozen states. Rehydration of the freeze-dried bone chips after 15 min with normal saline solution restores the strength of materials by 30%. The tensile strengths of fascia lata and dura mater are also studied. A marked decrease of tensile strength is noted in the irradiated and freeze-dried samples, however, reconstitution with normal saline solution restores the tensile strength of the tissues to about 40-56%. (author). 8 refs., 6figs

  8. Effects of pore shape and porosity on the properties of porous LNKN ceramics as bone substitute

    International Nuclear Information System (INIS)

    A porous lead-free piezoelectric ceramic is investigated as direct bone substitute. Porous lithium sodium potassium niobate (Li0.06Na0.5K0.44)NbO3 specimens were prepared by pore-forming method. Different volume fraction of ammonium oxalate monohydrate and poly(methyl methacrylate) were used as porogens to obtain different pore shape and porosity. Scanning electron microscopy showed a bicontinuous 3-3 structure of interconnected pores 150-250 μm in size. The piezoelectric constants and electromechanical coupling coefficients may be controlled by both size and shape of the porogens to tune for the best biological response. Such materials show promise for use as a piezoelectric composite bone substitute

  9. Strength properties and hydraulic properties of materials for monolithic barriers

    Energy Technology Data Exchange (ETDEWEB)

    Dotsenko, V.F.; Krikunenko, V.K.; Omel' chenko, A.S.; Denisova, G.F.

    1981-04-01

    This paper discusses investigations into physical and mechanical properties of gypsum cements used in underground black coal mines for construction of fire burners. Dependence of mechanical gypsum cement properties on proportion of water, gypsum and cement is analyzed. A formula for calculation of uniaxial compressive strength depending on water proportion is given. It is stated that relation between compressive strength and shear strength of gypsum cement is of major importance for investigations of fire barrier strength. The test stand used for static investigations of fire barrier models made of gypsum cement is described. Its design is given in a scheme. The proposed formulae permit the mechanical and physical properties of gypsum cements to be forecast on the basis of proportion of water, gypsum and cements in the mixture transported hydraulically to a fire zone. (In Russian)

  10. Prediction of biomechanical properties of trabecular bone in MR images with geometric features and support vector regression.

    Science.gov (United States)

    Huber, Markus B; Lancianese, Sarah L; Nagarajan, Mahesh B; Ikpot, Imoh Z; Lerner, Amy L; Wismuller, Axel

    2011-06-01

    Whole knee joint MR image datasets were used to compare the performance of geometric trabecular bone features and advanced machine learning techniques in predicting biomechanical strength properties measured on the corresponding ex vivo specimens. Changes of trabecular bone structure throughout the proximal tibia are indicative of several musculoskeletal disorders involving changes in the bone quality and the surrounding soft tissue. Recent studies have shown that MR imaging also allows non-invasive 3-D characterization of bone microstructure. Sophisticated features like the scaling index method (SIM) can estimate local structural and geometric properties of the trabecular bone and may improve the ability of MR imaging to determine local bone quality in vivo. A set of 67 bone cubes was extracted from knee specimens and their biomechanical strength estimated by the yield stress (YS) [in MPa] was determined through mechanical testing. The regional apparent bone volume fraction (BVF) and SIM derived features were calculated for each bone cube. A linear multiregression analysis (MultiReg) and a optimized support vector regression (SVR) algorithm were used to predict the YS from the image features. The prediction accuracy was measured by the root mean square error (RMSE) for each image feature on independent test sets. The best prediction result with the lowest prediction error of RMSE = 1.021 MPa was obtained with a combination of BVF and SIM features and by using SVR. The prediction accuracy with only SIM features and SVR (RMSE = 1.023 MPa) was still significantly better than BVF alone and MultiReg (RMSE = 1.073 MPa). The current study demonstrates that the combination of sophisticated bone structure features and supervised learning techniques can improve MR-based determination of trabecular bone quality. PMID:21356612

  11. Three-Dimensional Evaluation of Mandibular Bone Regenerated By Bone Transport Distraction Osteogenesis

    OpenAIRE

    Kontogiorgos, Elias; Elsalanty, Mohammed E.; Zapata, Uriel; Zakhary, Ibrahim; Nagy, William W; Dechow, Paul C.; Opperman, Lynne A.

    2011-01-01

    The purpose of this study was to evaluate the structure and material properties of native mandibular bone and those of early regenerate bone, produced by bone transport distraction osteogenesis. Ten adult foxhounds were divided into two groups of five animals each. In all animals, a 3- to 4-cm defect was created on one side of the mandible. A bone transport reconstruction plate, consisting of a reconstruction plate with an attached intraoral transport unit, was utilized to stabilize the mandi...

  12. Optimization of Structure and Material Properties for Solids Composed of Softening Material

    DEFF Research Database (Denmark)

    Bendsøe, Martin P.; Guedes, J.M.; J.M., Plaxton; Taylor, J.E.

    1996-01-01

    Recent results on the design of material properties in the context of global structural optimization provide, in analytical form, a prediction of the optimal material tensor distributions for two or three dimensional continuum structures. The model developed for that purpose is extended here to...... cover the design of a structure and associated material properties for a system composed of a generic form of nonlinear softening material. As was established in the earlier study on design with linear materials, the formulation for combined 'material and structure' design with softening materials can...... be expressed as a convex problem. However, the optimal distribution of material properties predicted in the nonlinear problem depends on the magnitude of load, in contrast to the case with linear material. Computational solutions are presented for several example problems, showing how the optimal...

  13. Effect of vacuum-treatment on deformation properties of PMMA bone cement.

    Science.gov (United States)

    Zivic, Fatima; Babic, Miroslav; Grujovic, Nenad; Mitrovic, Slobodan; Favaro, Gregory; Caunii, Mihaela

    2012-01-01

    Deformation behavior of polymethyl methacrylate (PMMA) bone cement is explored using microindentation. Two types of PMMA bone cement were prepared. Vacuum treated samples were subjected to the degassing of the material under vacuum of 270 mbar for 35 s, followed by the second degassing under vacuum of 255 mbar for 35 s. Air-cured samples were left in ambient air to cool down and harden. All samples were left to age for 6 months before the test. The samples were then subjected to the indentation fatigue test mode, using sharp Vickers indenter. First, loading segment rise time was varied in order to establish time-dependent behavior of the samples. Experimental data showed that viscous part of the deformation can be neglected under the observed test conditions. The second series of microindentation tests were realized with variation of number of cycles and indentation hardness and modulus were obtained. Approximate hardness was also calculated using analysis of residual impression area. Porosity characteristics were analyzed using CellC software. Scanning electron microscopy (SEM) analysis showed that air-cured bone cement exhibited significant number of large voids made of aggregated PMMA beads accompanied by particles of the radiopaque agent, while vacuum treated samples had homogeneous structure. Air-cured samples exhibited variable hardness and elasticity modulus throughout the material. They also had lower hardness values (approximately 65-100 MPa) than the vacuum treated cement (approximately 170 MPa). Porosity of 5.1% was obtained for vacuum treated cement and 16.8% for air-cured cement. Extensive plastic deformation, microcracks and craze whitening were produced during indentation of air-cured bone cement, whereas vacuum treated cement exhibited no cracks and no plastic deformation. PMID:22100087

  14. Biomimetic growth and substrate dependent mechanical properties of bone like apatite nucleated on Ti and magnetron sputtered TiO2 nanostructure

    Science.gov (United States)

    Sarma, Bimal K.; Das, Apurba; Barman, Pintu; Pal, Arup R.

    2016-04-01

    This report presents findings on biomimetic growth of hydroxyapatite (HAp) nanocrystals on Ti and sputtered TiO2 substrates. The possibility of TiO2 nanostructure as candidate materials for future biomedical applications has been explored through the comparison of microstructural and mechanical properties of bone like apatite grown on Ti and nano-TiO2 surfaces. Raman spectroscopy and x-ray diffraction studies reveal formation of carbonate apatite with apparent domain size in the nanoscale range. A better interaction at the nano-TiO2/nano-HAp interface due to higher interfacial area could promote the growth of bone like apatite. The crystal phases, crystallinity, and surface morphology of nano-TiO2 are considered as parameters to understand the nucleation and growth of apatite with different mechanical properties at the nanoscale. The methodology of x-ray line profile analysis encompasses deconvolution of merged peaks by preserving broadening due to nanosized HAp aggregates. The Young’s modulus of bone like apatite exhibits crystallographic directional dependence which suggests the presence of elastic anisotropy in bone like apatite. The lattice contraction in the c-direction is associated with the degree of carbonate substitution in the apatite lattice. The role of residual stress is critical for the lattice distortion of HAp deposited at physiological conditions of temperature and pH of human blood plasma. The ion concentration is crucial for the uniformity, crystallinity, and mechanical behaviour of the apatite.

  15. Size-Dependent Materials Properties Toward a Universal Equation

    Directory of Open Access Journals (Sweden)

    Guisbiers G

    2010-01-01

    Full Text Available Abstract Due to the lack of experimental values concerning some material properties at the nanoscale, it is interesting to evaluate this theoretically. Through a “top–down” approach, a universal equation is developed here which is particularly helpful when experiments are difficult to lead on a specific material property. It only requires the knowledge of the surface area to volume ratio of the nanomaterial, its size as well as the statistic (Fermi–Dirac or Bose–Einstein followed by the particles involved in the considered material property. Comparison between different existing theoretical models and the proposed equation is done.

  16. Tension mechanical properties of recycled glass-epoxy composite material

    OpenAIRE

    Petrović Jelena M.; Ljubić Darko M.; Stamenović Marina R.; Dimić Ivana D.; Putić Slaviša S.

    2012-01-01

    The significance of composite materials and their applications are mainly due to their good properties. This imposes the need for their recycling, thus extending their lifetime. Once used composite material will be disposed as a waste at the end of it service life. After recycling, this kind of waste can be used as raw materials for the production of same material, which raises their applicability. This indicates a great importance of recycling as a method of the renowal of composite ma...

  17. Properties of Sealing Materials in Groundwater Wells

    DEFF Research Database (Denmark)

    Köser, Claus

    years collected data on water chemistry from groundwater wells throughout the country. Based on these data it has been found that the levels of pesticides and their degradation products have been exceeded in many cases. The content of pesticides and degradation products can be the results of leaky...... pellets as sealing material in groundwater wells. The way and the pattern, in which bentonite pellets are deposited, have been shown to have an effect on the swelling pressure of the bentonite seal. During the transport phase of pellets from the terrain to a given sedimentation depth, a sorting process...... in this Ph.D. thesis, a number of recommendations has been offered; i) a change regarding the production of pellets and ii) how sealing material must be treated in the actual construction of groundwater wells....

  18. Pyroelectric materials, their properties and applications

    International Nuclear Information System (INIS)

    After a brief description of the pyroelectric effect and its measurement, pyroelectric materials are dealt with. Three groups of compounds such as single crystals, ceramics, and polymers are described. The values of pyroelectric coefficients, dielectric constants and Curie temperatures are given. The first group of materials contains triglycine salts and their derivatives, lithium salts and other inorganic salts, especially niobates. The second group contains the ceramics lead zirconate titanate (PZT), barium titanate, and lanthanum-doped PZT. In the polymer group especially polyvinylidene fluoride has been treated. The use of pyroelectric detectors can be found in a wide variety of applications and few of these have been mentioned such as infrared thermal imaging, non-contact infrared temperature sensing, pollution monitoring, intruder alarms, and laser diagnostics

  19. Mapping the fracture properties of engineering materials

    Science.gov (United States)

    Ashby, Mike

    2013-09-01

    Among Alan Cottrell's many extraordinary talents was that of an inspirational teacher. He had a masterful ability to explain the underlying physics of the Science of Materials and at the same time to simplify and to present the big picture. His teaching-texts live on, still among the clearest and most insightful expositions of the subject. This paper surveys part of one of the fields to which he contributed so much - Fracture - with education and the big picture in mind.

  20. Correlating morphology to macroscopic properties of disordered materials

    International Nuclear Information System (INIS)

    Current models of material properties are largely empirical, without sound theoretical connections to material microstructure. In the absence of any general theory, mechanical properties (elasticity, fracture toughness) and transport properties (thermal and electrical conductivity, permeability and diffusivity) of solids are usually correlated to the fraction of species by a simple empirical equation. Most experimental and theoretical work has been devoted to establishing the phenomenological correlation coefficients for different classes of materials. A general model for microstructure was recently proposed by Berk, based on level cuts of a Gaussian Random Field (GRF) with arbitrary spectral density. The freedom in specifying the parameters of the model allows the modelling of physical materials with diverse morphological characteristics. The authors show that the model qualitatively accounts for the principal features of a wider variety of disordered materials including geological media, membranes, polymer blends, ceramics and foams. Correlation functions for the model microstructure and the mechanical and conductive properties of the materials are derived. Excellent agreement with experimentally measured properties of disordered solids is obtained. Simple transport properties (thermal and electrical conductivity, permeability and diffusivity) have been simulated on parallel supercomputers and in all cases lie between the (sometimes mutually exclusive) bounds. Furthermore, the upper bound has been shown to have good predictive power. This has allowed the theoretical estimation of elastic properties: a result which is beyond current simulation techniques. 15 refs., 4 figs

  1. Fixation strength analysis of cup to bone material using finite element simulation

    Science.gov (United States)

    Anwar, Iwan Budiwan; Saputra, Eko; Ismail, Rifky; Jamari, J.; van der Heide, Emile

    2016-04-01

    Fixation of acetabular cup to bone material is an important initial stability for artificial hip joint. In general, the fixation in cement less-type acetabular cup uses press-fit and screw methods. These methods can be applied alone or together. Based on literature survey, the additional screw inside of cup is effective; however, it has little effect in whole fixation. Therefore, an acetabular cup with good fixation, easy manufacture and easy installation is required. This paper is aiming at evaluating and proposing a new cup fixation design. To prove the strength of the present cup fixation design, the finite element simulation of three dimensional cup with new fixation design was performed. The present cup design was examined with twist axial and radial rotation. Results showed that the proposed cup design was better than the general version.

  2. Advanced bioimaging technologies in assessment of the quality of bone and scaffold materials. Techniques and applications

    Energy Technology Data Exchange (ETDEWEB)

    Qin Ling; Leung, Kwok Sui (eds.) [Chinese Univ. of Hong Kong (China). Dept. of Orthopaedics and Traumatology; Genant, H.K. [California Univ., San Francisco, CA (United States); Griffith, J.F. [Chinese Univ. of Hong Kong (China). Dept. of Radiology and Organ Imaging

    2007-07-01

    This book provides a perspective on the current status of bioimaging technologies developed to assess the quality of musculoskeletal tissue with an emphasis on bone and cartilage. It offers evaluations of scaffold biomaterials developed for enhancing the repair of musculoskeletal tissues. These bioimaging techniques include micro-CT, nano-CT, pQCT/QCT, MRI, and ultrasound, which provide not only 2-D and 3-D images of the related organs or tissues, but also quantifications of the relevant parameters. The advance bioimaging technologies developed for the above applications are also extended by incorporating imaging contrast-enhancement materials. Thus, this book will provide a unique platform for multidisciplinary collaborations in education and joint R and D among various professions, including biomedical engineering, biomaterials, and basic and clinical medicine. (orig.)

  3. Advanced bioimaging technologies in assessment of the quality of bone and scaffold materials. Techniques and applications

    International Nuclear Information System (INIS)

    This book provides a perspective on the current status of bioimaging technologies developed to assess the quality of musculoskeletal tissue with an emphasis on bone and cartilage. It offers evaluations of scaffold biomaterials developed for enhancing the repair of musculoskeletal tissues. These bioimaging techniques include micro-CT, nano-CT, pQCT/QCT, MRI, and ultrasound, which provide not only 2-D and 3-D images of the related organs or tissues, but also quantifications of the relevant parameters. The advance bioimaging technologies developed for the above applications are also extended by incorporating imaging contrast-enhancement materials. Thus, this book will provide a unique platform for multidisciplinary collaborations in education and joint R and D among various professions, including biomedical engineering, biomaterials, and basic and clinical medicine. (orig.)

  4. Transport properties of colossal magnetoresistive materials

    CERN Document Server

    Yates, K A

    2002-01-01

    A microwave technique was developed in order to test the validity of the hypothesis that the microwave transport of polycrystalline, optimally doped, colossal magnetoresistive materials was dominated by intragranular material. The microwave surface resistance at 9GHz was compared with dc resistivity and magnetisation to study the influence of yttrium doping on the grain boundary regions of bulk polycrystalline samples of La sub 0 sub . sub 7 sub - sub x Y sub x Ca sub 0 sub . sub 3 MnO sub 3. It was found that, within the grains, the addition of yttrium causes the activation energy above T sub p to increase. A phenomenological model was introduced to explain the data in terms of the difference in structure between the grain and grain boundary regions. The technique was also used to study the influence of deoxygenation on the grain boundary regions of bulk, polycrystalline, La sub 0 sub . sub 6 sub 7 Ca sub 0 sub . sub 3 sub 3 MnO sub 3. For samples interconnected porosity, low temperature (600 deg C), short a...

  5. Spectroscopic properties of rare earths in optical materials

    CERN Document Server

    Parisi, Jürgen; Osgood, R; Warlimont, Hans; Liu, Guokui; Jacquier, Bernard

    2005-01-01

    Aimed at researchers and graduate students, this book provides up-to-date information for understanding electronic interactions that impact the optical properties of rare earth ions in solids. Its goal is to establish a connection between fundamental principles and the materials properties of rare-earth activated luminescent and laser optical materials. The theoretical survey and introduction to spectroscopic properties include electronic energy level structure, intensities of optical transitions, ion-phonon interactions, line broadening, and energy transfer and up-conversion. An important aspect of the book lies in its deep and detailed discussions on materials properties and the potential of new applications such as optical storage, information processing, nanophotonics, and molecular probes that have been identified in recent experimental studies. This volume will be a valuable reference book on advanced topics of rare earth spectroscopy and materials science.

  6. Scaling effect on the mid-diaphysis properties of long bones-the case of the Cervidae (deer).

    Science.gov (United States)

    Amson, Eli; Kolb, Christian

    2016-08-01

    How skeletal elements scale to size is a fundamental question in biology. While the external shape of long bones was intensively studied, an important component of their organization is also found in their less accessible inner structure. Here, we studied mid-diaphyseal properties of limb long bones, characterizing notably the thickness of their cortices (bone walls), in order to test whether body size directly influences bone inner organization. Previous examinations of scaling in long bones used broad samplings to encompass a wide range of body sizes. To account for the effect of confounding factors related to different lifestyles, we focused our comprehensive sampling on a mammalian clade that comprises various body sizes but a relatively uniform lifestyle, the Cervidae. Positive allometry was found in femoral cross-sectional shape, indicating greater directional bending rigidity in large-sized taxa. None of the compactness parameters scaled allometrically in any of their bones. The cortices of sampled zeugopodial bones (tibia and radius) were found as significantly thicker than those of stylopodial bones (femur and humerus). Furthermore, while the mean relative cortical thickness values for both stylopodial and zeugopodial bones are close to mass-saving optima, the variance for the stylopodial bones is significantly lower. This suggests that mass saving is less intensively selected in zeugopodial bones. Finally, the long-legged Elk (Alces) and the short-legged dwarf Cretan deer (Candiacervus) featured rather thin and thick cortices, respectively, suggesting that the acquisition of a different limb proportion is accompanied by a modification of the relative mid-diaphyseal cortical thickness. PMID:27350329

  7. Material properties of concentrated pectin networks.

    Science.gov (United States)

    Zsivanovits, Gabor; MacDougall, Alistair J; Smith, Andrew C; Ring, Stephen G

    2004-05-17

    We have examined the mechanical behaviour of different types of pectin at high concentrations (> 30% w/w), relevant to the behaviour of pectin in the plant cell wall, and as a film-forming agent. Mechanical properties were examined as a function of counterion type (K(+), Ca(2+), Mg(2+)), concentration and extent of hydration. Hydration was controlled in an osmotic stress experiment where pectin films were exposed to concentrated polyethylene glycol [PEG] solutions of known osmotic pressure. We investigated the mechanical behaviour under simple extension. The results show that the swelling and stiffness of the films are strongly dependent on pectin source and ionic environment. At a fixed osmotic stress, both Ca(2+) or Mg(2+) counterions reduce swelling and increase the stiffness of the film. PMID:15113669

  8. Surface properties of copper based cermet materials

    Energy Technology Data Exchange (ETDEWEB)

    Voinea, M. [The Centre: Product Design for Sustainable Development, Transilvania University of Brasov, Eroilor 29, 500036 (Romania)], E-mail: m.voinea@unitbv.ro; Vladuta, C.; Bogatu, C.; Duta, A. [The Centre: Product Design for Sustainable Development, Transilvania University of Brasov, Eroilor 29, 500036 (Romania)

    2008-08-25

    The paper presents the characterization of the surface properties of copper based cermets obtained by two different techniques: spray pyrolysis deposition (SPD) and electrodeposition. Copper acetate was used as precursor of Cu/CuO{sub x} cermet. The surface morphology was tailored by adding copolymers of maleic anhydride with controlled hydrophobia. The films morphology of Cu/CuO{sub x} was assessed using contact angle measurements and AFM analysis. The porous structures obtained via SPD lead to higher liquid adsorption rate than the electrodeposited films. A highly polar liquid - water is recommended as testing liquid in contact angle measurements, for estimating the porosity of copper based cermets, while glycerol can be used to distinguish among ionic and metal predominant structures. Thus, contact angle measurements can be used for a primary evaluation of the films morphology and, on the other hand, of the ratio between the cermet components.

  9. MD-portal Materials Database: Effective Materials Property Information Management in Nuclear Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Gyeonggeun; Kil, Soyeon; Kwon, Junhyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The collective properties of the nuclear materials are defined as standard industrial codes such as ASME codes. While in service, the materials are aged and degraded, and the initial properties are changed according to the operating environments. These changes are a matter of substantial concern of the operators, regulators, and researchers in nuclear fields. Hence, the material property database considering the degradation is required, and the successful management and use of material property information must be responsive to the continuing changes and increasing complexity in nuclear engineering materials. Recently, the nuclear materials division in the Korea Atomic Energy Research Institute (KAERI) launched a comprehensive portal website for nuclear material information, which is known as the MD-portal. The MD-portal contains various technical documents on the degradation and development of nuclear materials. Additionally, the nuclear materials database (MatDB) is incorporated in it. The MatDB covers the mechanical properties of various nuclear structural materials used as the components: a reactor pressure vessel, steam generator, and primary and secondary piping. In this study, we introduced the MD-portal MatDB briefly, and showed an application of the MatDB to the real case of material degradations in NPPs.

  10. MD-portal Materials Database: Effective Materials Property Information Management in Nuclear Energy Systems

    International Nuclear Information System (INIS)

    The collective properties of the nuclear materials are defined as standard industrial codes such as ASME codes. While in service, the materials are aged and degraded, and the initial properties are changed according to the operating environments. These changes are a matter of substantial concern of the operators, regulators, and researchers in nuclear fields. Hence, the material property database considering the degradation is required, and the successful management and use of material property information must be responsive to the continuing changes and increasing complexity in nuclear engineering materials. Recently, the nuclear materials division in the Korea Atomic Energy Research Institute (KAERI) launched a comprehensive portal website for nuclear material information, which is known as the MD-portal. The MD-portal contains various technical documents on the degradation and development of nuclear materials. Additionally, the nuclear materials database (MatDB) is incorporated in it. The MatDB covers the mechanical properties of various nuclear structural materials used as the components: a reactor pressure vessel, steam generator, and primary and secondary piping. In this study, we introduced the MD-portal MatDB briefly, and showed an application of the MatDB to the real case of material degradations in NPPs

  11. Some functional properties of composite material based on scrap tires

    Science.gov (United States)

    Plesuma, Renate; Malers, Laimonis

    2013-09-01

    The utilization of scrap tires still obtains a remarkable importance from the aspect of unloading the environment from non-degradable waste [1]. One of the most prospective ways for scrap tires reuse is a production of composite materials [2] This research must be considered as a continuation of previous investigations [3, 4]. It is devoted to the clarification of some functional properties, which are considered important for the view of practical applications, of the composite material. Some functional properties of the material were investigated, for instance, the compressive stress at different extent of deformation of sample (till 67% of initial thickness) (LVS EN 826) [5] and the resistance to UV radiation (modified method based on LVS EN 14836) [6]. Experiments were realized on the purposefully selected samples. The results were evaluated in the correlation with potential changes of Shore C hardness (Shore scale, ISO 7619-1, ISO 868) [7, 8]. The results showed noticeable resistance of the composite material against the mechanical influence and ultraviolet (UV) radiation. The correlation with the composition of the material, activity of binder, definite technological parameters, and the conditions supported during the production, were determined. It was estimated that selected properties and characteristics of the material are strongly dependent from the composition and technological parameters used in production of the composite material, and from the size of rubber crumb. Obtained results show possibility to attain desirable changes in the composite material properties by changing both the composition and technological parameters of examined material.

  12. Cellular and Porous Materials Thermal Properties Simulation and Prediction

    CERN Document Server

    Öchsner, Andreas; de Lemos, Marcelo J S

    2008-01-01

    Providing the reader with a solid understanding of the fundamentals as well as an awareness of recent advances in properties and applications of cellular and porous materials, this handbook and ready reference covers all important analytical and numerical methods for characterizing and predicting thermal properties. In so doing it directly addresses the special characteristics of foam-like and hole-riddled materials, combining theoretical and experimental aspects for characterization purposes.

  13. Structure and transport properties in organized polymeric materials

    CERN Document Server

    Cheiellini, E

    1998-01-01

    This multi-authored book includes selected contributions reviewing the results achieved in the synthesis and characterization of organized polymeric materials. The focus is on competitive materials with liquid crystalline or electroconductive properties. The fine tuning of the properties offered by advanced chemical synthesis has been investigated by a large number of state-of-the-art techniques, including both microscopic (ESR, NMR, dielectrometry, fluorescence, IR, Raman spectroscopy) and macroscopic (calorimetric, mechanical) methodologies. The book also provides an updated coverage of the

  14. Part and material properties in selective laser melting of metals

    OpenAIRE

    Kruth, Jean-Pierre; Badrossamay, Mohsen; Yasa, Evren; Deckers, Jan; Thijs, Lore; Van Humbeeck, Jan

    2010-01-01

    Recent technical improvements of additive manufacturing (AM) have shifted the application of these processes from prototyping to the production of end-use parts either as customised or series. Selective laser melting (SLM) holds a special place within the variety of AM processes due to the flexibility of materials being processed, and the capability to create functional components having mechanical properties comparable to those properties of bulk materials. The process, however, is character...

  15. Electrical properties of commercial sheet insulation materials for cryogenic applications

    Energy Technology Data Exchange (ETDEWEB)

    Tuncer, Enis [ORNL; Sauers, Isidor [ORNL; James, David Randy [ORNL; Ellis, Alvin R [ORNL; Pace, Marshall O [ORNL

    2008-01-01

    Dielectric properties of electrical insulation materials are needed for low-temperature power applications. Performance of materials and their compatibility determine the size of the electrical insulation in power equipment. In this work we report the dielectric properties of some commercially available materials in sheet form. The selected materials are polypropylene laminated paper from Sumitomo Electric U.S.A., Inc., porous polyethylene (Tyvek\\texttrademark) from Dupont, and polyamide paper (Nomex\\texttrademark) from Dupont. The dielectric properties are characterized with an electrical impedance analyzer in the frequency domain. The impedances are recorded in a cryocooler in the temperature range from 50 to 300 K. The dielectric breakdown characteristics of the materials are measured in a liquid nitrogen bath at atmospheric pressure.

  16. Experimental Study on the Comparison of the Material Properties of Glass Wool Used as Building Materials

    OpenAIRE

    Kim, Kyoung-Woo; Young-Sun JEONG

    2014-01-01

    Artificial mineral fibers such as glass wool or stone wool are commonly used in building walls, ceilings and floors as a major insulation material for buildings. Among the material properties of building materials, thermal conductivity, the sound absorption coefficient, compressibility, and dynamic stiffness are regarded as important performance requirements since they directly affect the thermal and acoustic properties of the building. This study measured the changes of the thermal and acous...

  17. Liquid Crystalline Semiconductors Materials, properties and applications

    CERN Document Server

    Kelly, Stephen; O'Neill, Mary

    2013-01-01

    This is an exciting stage in the development of organic electronics. It is no longer an area of purely academic interest as increasingly real applications are being developed, some of which are beginning to come on-stream. Areas that have already been commercially developed or which are under intensive development include organic light emitting diodes (for flat panel displays and solid state lighting), organic photovoltaic cells, organic thin film transistors (for smart tags and flat panel displays) and sensors. Within the family of organic electronic materials, liquid crystals are relative newcomers. The first electronically conducting liquid crystals were reported in 1988 but already a substantial literature has developed. The advantage of liquid crystalline semiconductors is that they have the easy processability of amorphous and polymeric semiconductors but they usually have higher charge carrier mobilities. Their mobilities do not reach the levels seen in crystalline organics but they circumvent all of t...

  18. Solder joint technology materials, properties, and reliability

    CERN Document Server

    Tu, King-Ning

    2007-01-01

    Solder joints are ubiquitous in electronic consumer products. The European Union has a directive to ban the use of Pb-based solders in these products on July 1st, 2006. There is an urgent need for an increase in the research and development of Pb-free solders in electronic manufacturing. For example, spontaneous Sn whisker growth and electromigration induced failure in solder joints are serious issues. These reliability issues are quite complicated due to the combined effect of electrical, mechanical, chemical, and thermal forces on solder joints. To improve solder joint reliability, the science of solder joint behavior under various driving forces must be understood. In this book, the advanced materials reliability issues related to copper-tin reaction and electromigration in solder joints are emphasized and methods to prevent these reliability problems are discussed.

  19. MIDAS (Material Implementation, Database, and Analysis Source): A comprehensive resource of material properties

    Energy Technology Data Exchange (ETDEWEB)

    Tang, M; Norquist, P; Barton, N; Durrenberger, K; Florando, J; Attia, A

    2010-12-13

    MIDAS is aimed to be an easy-to-use and comprehensive common source for material properties including both experimental data and models and their parameters. At LLNL, we will develop MIDAS to be the central repository for material strength related data and models with the long-term goal to encompass other material properties. MIDAS will allow the users to upload experimental data and updated models, to view and read materials data and references, to manipulate models and their parameters, and to serve as the central location for the application codes to access the continuously growing model source codes. MIDAS contains a suite of interoperable tools and utilizes components already existing at LLNL: MSD (material strength database), MatProp (database of materials properties files), and MSlib (library of material model source codes). MIDAS requires significant development of the computer science framework for the interfaces between different components. We present the current status of MIDAS and its future development in this paper.

  20. Functional Nanostructured Materials: Synthetic Aspects and Properties Evaluation

    OpenAIRE

    Chen, Fei

    2011-01-01

    In this dissertation, the synthesis of functional nanostructured materials including stimuli responsive nanomat composites, nanoparticles and biodegradable polyester nanofibers are presented. Further the novel properties such as controlled water absorption/desorption, fast thermo responsive properties and potential applications in biomedical and microelectronic fields were investigated. In chapter 4.1, photoresponsive sup...

  1. Materials thermal and thermoradiative properties/characterization technology

    Science.gov (United States)

    Dewitt, D. P.; Ho, C. Y.

    1989-01-01

    Reliable properties data on well characterized materials are necessary for design of experiments and interpretation of experimental results. The activities of CINDAS to provide data bases and predict properties are discussed. An understanding of emissivity behavior is important in order to select appropriate methods for non-contact temperature determination. Related technical issues are identified and recommendations are offered.

  2. Identification of effective properties of particle reinforced composite materials

    OpenAIRE

    Kushnevsky, V.; Morachkovsky, O.; Altenbach, H.

    1998-01-01

    For the determination of effective elastic properties an energy averaging procedure has been used for particle reinforced composite materials. This procedure is based on finite element calculations of the deformation energy of a characteristic volume element. The proposed approach allows the determination of effective properties of particle reinforced composite with acceptable precision. The calculated effective properties of the composite are found in range between upper and lower Hashin-Sht...

  3. Elastic properties of various ceramic materials

    International Nuclear Information System (INIS)

    The Young's modulus and the Poisson's ratio of various ceramics have been investigated at room temperature and compared with data from the literature. The ceramic materials investigated are Al2O3, Al2O3-ZrO2, MgAl2O4, LiAlO2, Li2SiO3, Li4SiO4, UO2, AlN, SiC, B4C, TiC, and TiB2. The dependence of the elastic moduli on porosity and temperature have been reviewed. Measurements were also performed on samples of Al2O3, AlN, and SiC, which had been irradiated to maximum neutron fluences of 1.6.1026 n/m2 (E>0.1 MeV) at different temperatures. The Young's modulus is nearly unaffected at fluences up to about 4.1024 n/m2. However, it decreases with increasing neutron fluence and seems to reach a saturation value depending upon the irradiation temperature. The reduction of the Young's modulus is lowest in SiC. (orig.)

  4. Material Properties for Fiber-Reinforced Silica Aerogels

    Science.gov (United States)

    White, Susan; Rouanet, Stephane; Moses, John; Arnold, James O. (Technical Monitor)

    1994-01-01

    Ceramic fiber-reinforced silica aerogels are novel materials for high performance insulation, including thermal protection materials. Experimental data are presented for the thermal and mechanical properties, showing the trends exhibited over a range of fiber loadings and silica aerogel densities. Test results are compared to that of unreinforced bulk aerogels.

  5. The design and modeling of periodic materials with novel properties

    Science.gov (United States)

    Berger, Jonathan Bernard

    Cellular materials are ubiquitous in our world being found in natural and engineered systems as structural materials, sound and energy absorbers, heat insulators and more. Stochastic foams made of polymers, metals and even ceramics find wide use due to their novel properties when compared to monolithic materials. Properties of these so called hybrid materials, those that combine materials or materials and space, are derived from the localization of thermomechanical stresses and strains on the mesoscale as a function of cell topology. The effects of localization can only be generalized in stochastic materials arising from their inherent potential complexity, possessing variations in local chemistry, microstructural inhomogeneity and topological variations. Ordered cellular materials on the other hand, such as lattices and honeycombs, make for much easier study, often requiring analysis of only a single unit-cell. Theoretical bounds predict that hybrid materials have the potential to push design envelopes offering lighter stiffer and stronger materials. Hybrid materials can achieve very low and even negative coefficients of thermal expansion (CTE) while retaining a relatively high stiffness -- properties completely unmatched by monolithic materials. In the first chapter of this thesis a two-dimensional lattice is detailed that possess near maximum stiffness, relative to the tightest theoretical bound, and low, zero and even appreciably negative thermal expansion. Its CTE and stiffness are given in closed form as a function of geometric parameters and the material properties. This result is confirmed with finite elements (FE) and experiment. In the second chapter the compressive stiffness of three-dimensional ordered foams, both closed and open cell, are predicted with FE and the results placed in property space in terms of stiffness and density. A novel structure is identified that effectively achieves theoretical bounds for Young's, shear and bulk modulus

  6. Perspective: Interactive material property databases through aggregation of literature data

    Science.gov (United States)

    Seshadri, Ram; Sparks, Taylor D.

    2016-05-01

    Searchable, interactive, databases of material properties, particularly those relating to functional materials (magnetics, thermoelectrics, photovoltaics, etc.) are curiously missing from discussions of machine-learning and other data-driven methods for advancing new materials discovery. Here we discuss the manual aggregation of experimental data from the published literature for the creation of interactive databases that allow the original experimental data as well additional metadata to be visualized in an interactive manner. The databases described involve materials for thermoelectric energy conversion, and for the electrodes of Li-ion batteries. The data can be subject to machine-learning, accelerating the discovery of new materials.

  7. Understanding Materials Science History · Properties · Applications

    CERN Document Server

    Hummel, Rolf E

    2005-01-01

    This introduction to materials science both for students of engineering and physics and for the interested general public examines not only the physical and engineering properties of virtually all kinds of materials, but also their history, uses, development, and some of the implications of resource depletion and recycling. It covers all topics on materials from an entirely novel perspective: the role materials have played throughout history in the development of humankind and technologies. Specifically, it shows the connection between the technical and the cultural, economic, ecological, and societal aspects of materials science. It aims to whet the appetite of its readers and inspire them to further explore the properties and applications of metals, alloys, ceramics, plastics, and electronic materials by presenting easily understandable explanations and entertaining historical facts. It is also intended to raise the reader’s awareness of their obligations to society as practicing engineers and scientists....

  8. Bone augmentation procedures in localized defects in the alveolar ridge: clinical results with different bone grafts and bone-substitute materials

    DEFF Research Database (Denmark)

    Jensen, Simon Storgård; Terheyden, Hendrik

    2009-01-01

    -type defects, (2) horizontal ridge augmentations, (3) vertical ridge augmentations, and (4) maxillary sinus floor elevations using the lateral window technique or transalveolar approach. The review focused on: (1) the outcome of the individual grafting protocols and (2) survival rates of implants placed in the...... evidence except expert opinions. Any publication written in English and including 10 or more patients with at least 12 months of follow-up after loading of the implants was eligible for this review. The results were categorized according to the presenting defect type: (1) dehiscence and fenestration...... of evidence (level A to B) to support that survival rates of implants placed in augmented bone are comparable to rates of implants placed in pristine bone....

  9. Compact rock material gas permeability properties

    International Nuclear Information System (INIS)

    Natural compact rocks, such as sandstone, granite, and rock salt, are the main materials and geological environment for storing underground oil, gas, CO2, shale gas, and radioactive waste because they have extremely low permeabilities and high mechanical strengths. Using the inert gas argon as the fluid medium, the stress-dependent permeability and porosity of monzonitic granite and granite gneiss from an underground oil storage depot were measured using a permeability and porosity measurement system. Based on the test results, models for describing the relationships among the permeability, porosity, and confining pressure of rock specimens were analyzed and are discussed. A power law is suggested to describe the relationship between the stress-dependent porosity and permeability; for the monzonitic granite and granite gneiss (for monzonitic granite (A-2), the initial porosity is approximately 4.05%, and the permeability is approximately 10−19 m2; for the granite gneiss (B-2), the initial porosity is approximately 7.09%, the permeability is approximately 10−17 m2; and the porosity-sensitivity exponents that link porosity and permeability are 0.98 and 3.11, respectively). Compared with moderate-porosity and high-porosity rocks, for which φ > 15%, low-porosity rock permeability has a relatively lower sensitivity to stress, but the porosity is more sensitive to stress, and different types of rocks show similar trends. From the test results, it can be inferred that the test rock specimens’ permeability evolution is related to the relative particle movements and microcrack closure

  10. Compact rock material gas permeability properties

    Science.gov (United States)

    Wang, Huanling; Xu, Weiya; Zuo, Jing

    2014-09-01

    Natural compact rocks, such as sandstone, granite, and rock salt, are the main materials and geological environment for storing underground oil, gas, CO2, shale gas, and radioactive waste because they have extremely low permeabilities and high mechanical strengths. Using the inert gas argon as the fluid medium, the stress-dependent permeability and porosity of monzonitic granite and granite gneiss from an underground oil storage depot were measured using a permeability and porosity measurement system. Based on the test results, models for describing the relationships among the permeability, porosity, and confining pressure of rock specimens were analyzed and are discussed. A power law is suggested to describe the relationship between the stress-dependent porosity and permeability; for the monzonitic granite and granite gneiss (for monzonitic granite (A-2), the initial porosity is approximately 4.05%, and the permeability is approximately 10-19 m2; for the granite gneiss (B-2), the initial porosity is approximately 7.09%, the permeability is approximately 10-17 m2; and the porosity-sensitivity exponents that link porosity and permeability are 0.98 and 3.11, respectively). Compared with moderate-porosity and high-porosity rocks, for which φ > 15%, low-porosity rock permeability has a relatively lower sensitivity to stress, but the porosity is more sensitive to stress, and different types of rocks show similar trends. From the test results, it can be inferred that the test rock specimens' permeability evolution is related to the relative particle movements and microcrack closure.

  11. Structure and properties of sintered tool gradient materials

    OpenAIRE

    L.A. Dobrzański; B. Dołżańska

    2010-01-01

    Purpose: The main objective of the presented is to elaborate the fabrication technology of novel sintered tool gradient materials on the basis of hard wolfram carbide phase with cobalt binding phase, and to carry out research studies on the structure and properties of the newly elaborated sintered tool gradient materials.Design/methodology/approach: The following research studies have been carried out to elaborate a new group of sintered tool gradient materials, wolfram carbide with cobalt ma...

  12. Composite materials based on glass fabrics and siloxane matrix as substitutive and connective elements of bones in orthopaedics

    Czech Academy of Sciences Publication Activity Database

    Balík, Karel; Sochor, M.; Hulejová, H.; Černý, Martin; Pešáková, V.; Suchý, Tomáš; Sedláček, R.; Sucharda, Zbyněk

    -, č. 15 (2006), s. 39-45. ISSN 1214-9691 R&D Projects: GA ČR GA106/06/1576 Institutional research plan: CEZ:AV0Z30460519 Keywords : bone plates * composite * glass fiber Subject RIV: JI - Composite Materials

  13. Impact of carbonation on water transport properties of cementitious materials

    International Nuclear Information System (INIS)

    Carbonation is a very well-known cementitious materials pathology. It is the major cause of reinforced concrete structures degradation. It leads to rebar corrosion and consequent concrete cover cracking. In the framework of radioactive waste management, cement-based materials used as building materials for structures or containers would be simultaneously submitted to drying and atmospheric carbonation. Although scientific literature regarding carbonating is vast, it is clearly lacking information about the influence of carbonation on water transport properties. This work then aimed at studying and understanding the change in water transport properties induced by carbonation. Simultaneously, the representativeness of accelerated carbonation (in the laboratory) was also studied. (author)

  14. Tension mechanical properties of recycled glass-epoxy composite material

    Directory of Open Access Journals (Sweden)

    Petrović Jelena M.

    2012-01-01

    Full Text Available The significance of composite materials and their applications are mainly due to their good properties. This imposes the need for their recycling, thus extending their lifetime. Once used composite material will be disposed as a waste at the end of it service life. After recycling, this kind of waste can be used as raw materials for the production of same material, which raises their applicability. This indicates a great importance of recycling as a method of the renowal of composite materials. This study represents a contribution to the field of mechanical properties of the recycled composite materials. The tension mechanical properties (tensile strength and modulus of elasticity of once used and disposed glass-epoxy composite material were compared before and after the recycling. The obtained results from mechanical tests confirmed that the applied recycling method was suitable for glass-epoxy composite materials. In respect to the tensile strength and modulus of elasticity it can be further assessed the possibility of use of recycled glass-epoxy composite materials.

  15. Electromechanical actuation of buckypaper actuator: Material properties and performance relationships

    International Nuclear Information System (INIS)

    Carbon nanotubes can be assembled into macroscopic thin film materials called buckypapers. To incorporate buckypaper actuators into engineering systems, it is of high importance to understand their material property-actuation performance relationships in order to model and predict the behavior of these actuators. The electromechanical actuation of macroscopic buckypaper structures and their actuators, including single and multi-walled carbon nanotube buckypapers and aligned single-walled nanotube buckypapers, were analyzed and compared. From the experimental evidence, this Letter discusses the effects of the fundamental material properties, including Young modulus and electrical double layer properties, on actuation performance of the resultant actuators. -- Highlights: ► In this study we identified the figure of merit of the electromechanical conversion. ► Different type of buckypaper was realized and characterized for actuation properties. ► The results demonstrated the potential of Buckypapers/Nafion for actuation

  16. Finite Element Method for Analysis of Material Properties

    DEFF Research Database (Denmark)

    Rauhe, Jens Christian

    The use of cellular and composite materials have in recent years become more and more common in all kinds of structural components and accurate knowledge of the effective properties is therefore essential. In this wok the effective properties are determined using the real material microstructure...... determined using theoretical models. Besides the determination of the effective properties, viscoelastic and damage analysis have been performed on a number of material microstructures....... obtain a proper description of the material microstructure the finite element models must contain a large number of elements and this problem is solved by using the preconditioned conjugated gradient solver with an Element-By-Element preconditioner. Finite element analysis provides the volume averaged...

  17. A method of determining bending properties of poultry long bones using beam analysis and micro-CT data.

    Science.gov (United States)

    Vaughan, Patrick E; Orth, Michael W; Haut, Roger C; Karcher, Darrin M

    2016-01-01

    While conventional mechanical testing has been regarded as a gold standard for the evaluation of bone heath in numerous studies, with recent advances in medical imaging, virtual methods of biomechanics are rapidly evolving in the human literature. The objective of the current study was to evaluate the feasibility of determining the elastic and failure properties of poultry long bones using established methods of analysis from the human literature. In order to incorporate a large range of bone sizes and densities, a small number of specimens were utilized from an ongoing study of Regmi et al. (2016) that involved humeri and tibiae from 3 groups of animals (10 from each) including aviary, enriched, and conventional housing systems. Half the animals from each group were used for 'training' that involved the development of a regression equation relating bone density and geometry to bending properties from conventional mechanical tests. The remaining specimens from each group were used for 'testing' in which the mechanical properties from conventional tests were compared to those predicted by the regression equations. Based on the regression equations, the coefficients of determination for the 'test' set of data were 0.798 for bending bone stiffness and 0.901 for the yield (or failure) moment of the bones. All regression slopes and intercepts values for the tests versus predicted plots were not significantly different from 1 and 0, respectively. The study showed the feasibility of developing future methods of virtual biomechanics for the evaluation of poultry long bones. With further development, virtual biomechanics may have utility in future in vivo studies to assess laying hen bone health over time without the need to sacrifice large groups of animals at each time point. PMID:26794840

  18. Differences in electrophysiological properties of functionally identified nociceptive sensory neurons in an animal model of cancer-induced bone pain

    Science.gov (United States)

    Zhu, Yong Fang; Ungard, Robert; Seidlitz, Eric; Zacal, Natalie; Huizinga, Jan; Henry, James L

    2016-01-01

    Background Bone cancer pain is often severe, yet little is known about mechanisms generating this type of chronic pain. While previous studies have identified functional alterations in peripheral sensory neurons that correlate with bone tumours, none has provided direct evidence correlating behavioural nociceptive responses with properties of sensory neurons in an intact bone cancer model. Results In a rat model of prostate cancer-induced bone pain, we confirmed tactile hypersensitivity using the von Frey test. Subsequently, we recorded intracellularly from dorsal root ganglion neurons in vivo in anesthetized animals. Neurons remained connected to their peripheral receptive terminals and were classified on the basis of action potential properties, responses to dorsal root stimulation, and to mechanical stimulation of the respective peripheral receptive fields. Neurons included C-, Aδ-, and Aβ-fibre nociceptors, identified by their expression of substance P. We suggest that bone tumour may induce phenotypic changes in peripheral nociceptors and that these could contribute to bone cancer pain. Conclusions This work represents a significant technical and conceptual advance in the study of peripheral nociceptor functions in the development of cancer-induced bone pain. This is the first study to report that changes in sensitivity and excitability of dorsal root ganglion primary afferents directly correspond to mechanical allodynia and hyperalgesia behaviours following prostate cancer cell injection into the femur of rats. Furthermore, our unique combination of techniques has allowed us to follow, in a single neuron, mechanical pain-related behaviours, electrophysiological changes in action potential properties, and dorsal root substance P expression. These data provide a more complete understanding of this unique pain state at the cellular level that may allow for future development of mechanism-based treatments for cancer-induced bone pain. PMID:27030711

  19. Commercially pure titanium (cp-Ti) versus titanium alloy (Ti6Al4V) materials as bone anchored implants - Is one truly better than the other?

    Science.gov (United States)

    Shah, Furqan A; Trobos, Margarita; Thomsen, Peter; Palmquist, Anders

    2016-05-01

    Commercially pure titanium (cp-Ti) and titanium alloys (typically Ti6Al4V) display excellent corrosion resistance and biocompatibility. Although the chemical composition and topography are considered important, the mechanical properties of the material and the loading conditions in the host have, conventionally, influenced material selection for different clinical applications: predominantly Ti6Al4V in orthopaedics while cp-Ti in dentistry. This paper attempts to address three important questions: (i) To what extent do the surface properties differ when cp-Ti and Ti6Al4V materials are manufactured with the same processing technique?, (ii) Does bone tissue respond differently to the two materials, and (iii) Do bacteria responsible for causing biomaterial-associated infections respond differently to the two materials? It is concluded that: (i) Machined cp-Ti and Ti6Al4V exhibit similar surface morphology, topography, phase composition and chemistry, (ii) Under experimental conditions, cp-Ti and Ti6Al4V demonstrate similar osseointegration and biomechanical anchorage, and (iii) Experiments in vitro fail to disclose differences between cp-Ti and Ti6Al4V to harbour Staphylococcus epidermidis growth. No clinical comparative studies exist which could determine if long-term, clinical differences exist between the two types of bulk materials. It is debatable whether cp-Ti or Ti6Al4V exhibit superiority over the other, and further comparative studies, particularly in a clinical setting, are required. PMID:26952502

  20. MPOD: A Material Property Open Database linked to structural information

    International Nuclear Information System (INIS)

    Inspired by the Crystallography Open Database (COD), the Material Properties Open Database (MPOD) was given birth. MPOD aims at collecting and making publicly available at no charge tensorial properties (including scalar properties) of phases and linking such properties to structural information of the COD when available. MPOD files are written with the STAR file syntax, used and developed for the Crystallographic Information Files. A dictionary containing new definitions has been written according to the Dictionary Definition Language 1, although some tricks were adopted to allow for multiple entries still avoiding ambiguousness. The initial set includes mechanical properties, elastic stiffness and compliance, internal friction; electrical properties, resistivity, dielectric permittivity and stiffness, thermodynamic properties, heat capacity, thermal conductivity, diffusivity and expansion; electromechanical properties, piezoelectricity, electrostriction, electromechanical coupling; optical properties; piezooptic and photoelastic properties; superconducting properties, critical fields, penetration and coherence lengths. Properties are reported in MPOD files where the original published paper containing the data is cited and structural and experimental information is also given. One MPOD file contains information relative to only one publication and one phase. The files and the information contained therein can also be consulted on-line at (http://www.materialproperties.org).

  1. Compound soft regenerated skull material for repairing dog skull defects using bone morphogenetic protein as an inductor and nanohydroxyapatite as a scaffold

    Institute of Scientific and Technical Information of China (English)

    Zhidong Shi; Mingwang Liu; Zhongzong Qin; Qinmei Wang; Ying Guo; Haiyong He; Zhonghe Yu

    2008-01-01

    BACKGROUND: In previous studies of skull defects and regeneration, bone morphogenetic protein as an inductor and nanohydroxyapatite as a scaffold have been cocultured with osteoblasts.OBJECTIVE: To verify the characteristics of the new skull regenerated material after compound soft regenerated skull material implantatiom.DESIGN, TIME AND SETTING: The self-control and inter-group control animal experiment was perfurmed at the Sun Yat-sen University, China from February to July 2007.MATERIALS: Twenty-tour healthy adult dogs of both genders weighing 15-20 kg were used in this study. Nanohydroxyapatite as a scaffold was cocultured with osteoblasts. Using demineralized canine bone matrix as a carrier, recombinant human bone morphogenetic protein-2 was employed to prepare compound soft regenerated skull material. Self-designed compound soft regenerated skull material was implanted in models of skull defects.METHODS: Animals were randomly assigned into two groups, Group A (n = 16) and Group B (n = 8).Bilateral 2.5-cm-diameter full-thickness parietal skull defects were made in all animals. In Group A, the right side was reconstructed with calcium alginate gel, osteoblasts, and nanomcter bone meal composite;the left side was reconstructed with calcium alginate gel, osteoblasts, nanometer bone meal and recombinant human bone morphogenetic protein-2 composite. In Group B, the right side was kept as a simple skull detect, and the left side was reconstructed with calcium alginate gel, osteoblasts, nanometer bone meal and recombinant human bone morphogenetic protein-2 composite.MAIN OUTCOME MEASURES: Bone regeneration and histopathological changes at the site of the skull defect were observed with an optical microscope and a scanning electron microscope after surgery.The ability to form bone was measured by alizarin red S staining. In vitro cultured osteoblasts were observed for morphology.RESULTS: One month following surgery, newly formed bone trabeculae mostly covered the

  2. Synthesis, Properties and Mineralogy of Important Inorganic Materials

    DEFF Research Database (Denmark)

    Warner, Terence Edwin

    The synthesis of high quality material is an essential step in the process of obtaining meaningful information about the material’s properties, and therefore, is an important link between physics and chemistry. Semiconductors; superconductors; solid-electrolytes; glasses; pigments; dielectric, fe...... chemistry; inorganic chemistry; solid state chemistry; solid state physics; materials chemistry; and mineralogy; and so they will not be repeated here. To this respect, the various footnotes refer the reader to a selection of relevant texts.......The synthesis of high quality material is an essential step in the process of obtaining meaningful information about the material’s properties, and therefore, is an important link between physics and chemistry. Semiconductors; superconductors; solid-electrolytes; glasses; pigments; dielectric......, ferroelectric, thermoelectric, luminescent, photochromic and magnetic materials; are technologically important classes of material, that are represented by numerous inorganic phases. Yet how many of us are aware of their precise chemical compositions, and have sufficient knowledge to actually make them...

  3. A Summary of the Fatigue Properties of Wind Turbine Materials

    Energy Technology Data Exchange (ETDEWEB)

    SUTHERLAND, HERBERT J.

    1999-10-07

    Modern wind turbines are fatigue critical machines that are typically used to produce electrical power from the wind. The materials used to construct these machines are subjected to a unique loading spectrum that contains several orders of magnitude more cycles than other fatigue critical structures, e.g., an airplane. To facilitate fatigue designs, a large database of material properties has been generated over the past several years that is specialized to materials typically used in wind turbines. In this paper, I review these fatigue data. Major sections are devoted to the properties developed for wood, metals (primarily aluminum) and fiberglass. Special emphasis is placed on the fiberglass discussion because this material is current the material of choice for wind turbine blades. The paper focuses on the data developed in the U.S., but cites European references that provide important insights.

  4. Angiogenic factor-enriched platelet-rich plasma enhances in vivo bone formation around alloplastic graft material

    OpenAIRE

    Kim, Eun-Seok; Kim, Jae-Jin; Park, Eun-Jin

    2010-01-01

    PURPOSE Although most researchers agree that platelet-rich plasma (PRP) is a good source of autogenous growth factors, its effect on bone regeneration is still controversial. The purpose of this study was to evaluate whether increasing angiogenic factors in the human PRP to enhance new bone formation through rapid angiogenesis. MATERIAL AND METHODS In vitro, the human platelets were activated with application of shear stress, 20 µg/ml collagen, 2 mM CaCl2 and 10U thrombin/1 × 109 platelets. L...

  5. Use of dietary Ca and P and photon absorptiometry to predict mechanical properties of bone in swine

    International Nuclear Information System (INIS)

    Photjon absorptiometry provides a noninvasive method to determine bone mineral content (BMC) in patients, yet the relationship of BMC and mechanical properties of bone has not been established. To establish the relationship between mechanical properties of bone and BMC, the third metatarsal bones (MT) from 72 growing pigs (23.4 +- 2.5 kg) were collected after either 5, 10 or 15 weeks (T1, T2 and T3) of being fed 1 of 9 treatments. A central composite response surface design was utilized to provide a range of Ca (0.4 to 1.2%) and P (0.4 to 1.2%) levels. Using photon absorptiometry, BMC was predicted from four scans on the midshaft of excised bone, mechanical tests (3-point flexure test) were made and the bone was ashed. BMC can predict force (r2 = 0.89) and ash (r2 = 0.97);however, interactions with Ca, P and T were detected. Stress was not predicted reliably with BMC (r2 = 0.43), ash (r2 = 0.40) or dietary Ca and P (r2 = 0.41)

  6. The Development of Biomimetic Spherical Hydroxyapatite/Polyamide 66 Biocomposites as Bone Repair Materials

    OpenAIRE

    Xuesong (Sonya) Zhang; Ming Lu; Yan Wang; Xiaojing Su; Xuelian Zhang

    2014-01-01

    A novel biomedical material composed of spherical hydroxyapatite (s-HA) and polyamide 66 (PA) biocomposite (s-HA/PA) was prepared, and its composition, mechanical properties, and cytocompatibility were characterized and evaluated. The results showed that HA distributed uniformly in the s-HA/PA matrix. Strong molecule interactions and chemical bonds were presented between the s-HA and PA in the composites confirmed by IR and XRD. The composite had excellent compressive strength in the range be...

  7. Acoustical properties of selected tissue phantom materials for ultrasound imaging

    Energy Technology Data Exchange (ETDEWEB)

    Zell, K [Chair for Analytical Chemistry, Technische Universitaet Muenchen, Munich (Germany); Sperl, J I [GE Global Research-Europe, Advanced Medical Applications Laboratory, Garching (Germany); Vogel, M W [GE Global Research-Europe, Advanced Medical Applications Laboratory, Garching (Germany); Niessner, R [Chair for Analytical Chemistry, Technische Universitaet Muenchen, Munich (Germany); Haisch, C [Chair for Analytical Chemistry, Technische Universitaet Muenchen, Munich (Germany)

    2007-10-21

    This note summarizes the characterization of the acoustic properties of four materials intended for the development of tissue, and especially breast tissue, phantoms for the use in photoacoustic and ultrasound imaging. The materials are agar, silicone, polyvinyl alcohol gel (PVA) and polyacrylamide gel (PAA). The acoustical properties, i.e., the speed of sound, impedance and acoustic attenuation, are determined by transmission measurements of sound waves at room temperature under controlled conditions. Although the materials are tested for application such as photoacoustic phantoms, we focus here on the acoustic properties, while the optical properties will be discussed elsewhere. To obtain the acoustic attenuation in a frequency range from 4 MHz to 14 MHz, two ultrasound sources of 5 MHz and 10 MHz core frequencies are used. For preparation, each sample is cast into blocks of three different thicknesses. Agar, PVA and PAA show similar acoustic properties as water. Within silicone polymer, a significantly lower speed of sound and higher acoustical attenuation than in water and human tissue were found. All materials can be cast into arbitrary shapes and are suitable for tissue-mimicking phantoms. Due to its lower speed of sound, silicone is generally less suitable than the other presented materials. (note)

  8. Experimental Research on Properties of Materials of Grounding Resistor

    Directory of Open Access Journals (Sweden)

    He Da-Jiang

    2013-03-01

    Full Text Available In this study, we have a experimental research on properties of materials of grounding resistor. Experiment test of the grounding resistor in the state of analog ground fault have been done, the performance parameters on the mechanics, thermal and electrical of alloy materials with different kinds and different specification have been got. The performance and its character of alloy materials have been grasped in the state of analog ground fault by analysis and processing. The research results have an important significance on the material selection and structure design of low resistance grounding resistor.

  9. Physical properties and Analysis of Electrical and Electronic Materials

    International Nuclear Information System (INIS)

    This book consists of 11 chapters. It covers basic quantum theory, schrodinger wave equation and value as well as probability and statistical mechanics in chapter 1- chapter 3. In chapter 4 and 5, it deals with state of materials determination and structure of materials determination. You will also study properties of materials such as electrical, magnetic, optical, thermal and mechanical ones in from chapter 6 to chapter 8. Lastly, you will learn semiconductor electronic theory, semiconductor devices and analysis method and principle of materials from chapter 9 to chapter 11.

  10. Mechanical Properties of Nanostructured Materials Determined Through Molecular Modeling Techniques

    Science.gov (United States)

    Clancy, Thomas C.; Gates, Thomas S.

    2005-01-01

    The potential for gains in material properties over conventional materials has motivated an effort to develop novel nanostructured materials for aerospace applications. These novel materials typically consist of a polymer matrix reinforced with particles on the nanometer length scale. In this study, molecular modeling is used to construct fully atomistic models of a carbon nanotube embedded in an epoxy polymer matrix. Functionalization of the nanotube which consists of the introduction of direct chemical bonding between the polymer matrix and the nanotube, hence providing a load transfer mechanism, is systematically varied. The relative effectiveness of functionalization in a nanostructured material may depend on a variety of factors related to the details of the chemical bonding and the polymer structure at the nanotube-polymer interface. The objective of this modeling is to determine what influence the details of functionalization of the carbon nanotube with the polymer matrix has on the resulting mechanical properties. By considering a range of degree of functionalization, the structure-property relationships of these materials is examined and mechanical properties of these models are calculated using standard techniques.

  11. Development and Demonstration of Material Properties Database and Software for the Simulation of Flow Properties in Cementitious Materials

    Energy Technology Data Exchange (ETDEWEB)

    Smith, F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Flach, G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-03-30

    This report describes work performed by the Savannah River National Laboratory (SRNL) in fiscal year 2014 to develop a new Cementitious Barriers Project (CBP) software module designated as FLOExcel. FLOExcel incorporates a uniform database to capture material characterization data and a GoldSim model to define flow properties for both intact and fractured cementitious materials and estimate Darcy velocity based on specified hydraulic head gradient and matric tension. The software module includes hydraulic parameters for intact cementitious and granular materials in the database and a standalone GoldSim framework to manipulate the data. The database will be updated with new data as it comes available. The software module will later be integrated into the next release of the CBP Toolbox, Version 3.0. This report documents the development efforts for this software module. The FY14 activities described in this report focused on the following two items that form the FLOExcel package; 1) Development of a uniform database to capture CBP data for cementitious materials. In particular, the inclusion and use of hydraulic properties of the materials are emphasized; and 2) Development of algorithms and a GoldSim User Interface to calculate hydraulic flow properties of degraded and fractured cementitious materials. Hydraulic properties are required in a simulation of flow through cementitious materials such as Saltstone, waste tank fill grout, and concrete barriers. At SRNL these simulations have been performed using the PORFLOW code as part of Performance Assessments for salt waste disposal and waste tank closure.

  12. Thermophysical properties of materials for water cooled reactors

    International Nuclear Information System (INIS)

    The IAEA Co-ordinated Research Programme (CRP) to establish a thermophysical properties data base for light and heavy water reactor materials was organized within the framework of the IAEA's International Working Group on Advanced Technologies for Water Cooled Reactors. The work within the CRP started in 1990. The objective of the CRP was to collect and systemaize a thermophysical properties data base for light and heavy water reactor materials under normal operating, transient and accident conditions. The important thermophysical properties include thermal conductivity, thermal diffusivity, specific heat capacity, enthalpy, thermal expansion and others. These properties as well as the oxidation of zirconium-based alloys, the thermophysical characteristics of high temperature concrete-core melt interaction and the mechanical properties of construction materials are presented in this report. It is hoped that this report will serve as a useful source of thermophysical properties data for water cooled reactor analyses. The properties data are maintained on the THERSYST system at the University of Stuttgart, Germany and are internationally available. Refs, figs, tabs

  13. Effects of short-term swimming exercise on bone mineral density, geometry, and microstructural properties in sham and ovariectomized rats

    Directory of Open Access Journals (Sweden)

    Foong Kiew Ooi

    2014-12-01

    Full Text Available Little information exists about the effects of swimming exercise on bone health in ovariectomized animals with estrogen deficiency, which resembles the postmenopausal state and age-related bone loss in humans. This study investigated the effects of swimming exercise on tibia and femur bone mineral density (BMD, geometry, and microstructure in sham and ovariectomized rats. Forty 3-month-old female rats were divided into four groups: sham operated-sedentary control (Sham-control, sham operated with swimming exercise group (Sham-Swim, ovariectomy-sedentary control (OVx-control, and ovariectomy and swimming exercise (OVx-Swim groups. Swimming sessions were performed by the rats 90 minutes/day for 5 days/week for a total of 8 weeks. At the end of the study, tibial and femoral proximal volumetric total BMD, midshaft cortical volumetric BMD, cross-sectional area, and cross-sectional moment of inertia (MOI, and bone microstructural properties were measured for comparison. Data were analyzed using one-way analysis of variance (ANOVA. The Sham-Swim group exhibited significantly (p < 0.05; one-way ANOVA greater values in bone geometry parameters, that is, tibial midshaft cortical area and MOI compared to the Sham-control group. However, no significant differences were observed in these parameters between the Ovx-Swim and Ovx-control groups. There were no significant differences in femoral BMD between the Sham-Swim and Sham-control groups. Nevertheless, the Ovx-Swim group elicited significantly (p < 0.05; one-way ANOVA higher femoral proximal total BMD and improved bone microstructure compared to the Ovx-Sham group. In conclusion, the positive effects of swimming on bone properties in the ovariectomized rats in the present study may suggest that swimming as a non- or low-weight-bearing exercise may be beneficial for enhancing bone health in the postmenopausal population.

  14. Control over magnetic properties in bulk hybrid materials

    Science.gov (United States)

    Urban, Christian; Quesada, Adrian; Saerbeck, Thomas; Rubia, Miguel Angel De La; Garcia, Miguel Angel; Fernandez, Jose Francisco; Schuller, Ivan K.; UCSD Collaboration; Instituto de Ceramica, Madrid Collaboration; Institut Laue-Langevin, Grenoble Collaboration

    We present control of coercivity and remanent magnetization of a bulk ferromagnetic material embedded in bulk vanadium sesquioxide (V2O3) by using a standard bulk synthesis procedure. The method generalizes the use of structural phase transitions of one material to control structural and magnetic properties of another. A structural phase transition (SPT) in the V2O3 host material causes magnetic properties of Ni to change as function of temperature. The remanent magnetization and the coercivity are reversibly controlled by the SPT without additional external magnetic fields. The reversible tuning shown here opens the pathway for controlling the properties of a vast variety of magnetic hybrid bulk systems. This Work is supported by the Office of Basic Energy Science, U.S. Department of Energy, BES-DMS funded by the Department of Energy's Office of Basic Energy Science, DMR under grant DE FG02 87ER-45332.

  15. Flow-induced properties of nanotube-filled polymer materials.

    Science.gov (United States)

    Kharchenko, Semen B; Douglas, Jack F; Obrzut, Jan; Grulke, Eric A; Migler, Kalman B

    2004-08-01

    Carbon nanotubes (CNTs) are under intense investigation in materials science owing to their potential for modifying the electrical conductivity sigma, shear viscosity eta, and other transport properties of polymeric materials. These particles are hybrids of filler and nanoscale additives because their lengths are macroscopic whereas their cross-sectional dimensions are closer to molecular scales. The combination of extended shape, rigidity and deformability allows CNTs to be mechanically dispersed in polymer matrices in the form of disordered 'jammed' network structures. Our measurements on representative network-forming multiwall nanotube (MWNT) dispersions in polypropylene indicate that these materials exhibit extraordinary flow-induced property changes. Specifically, sigma and eta both decrease strongly with increasing shear rate, and these nanocomposites exhibit impressively large and negative normal stress differences, a rarely reported phenomenon in soft condensed matter. We illustrate the practical implications of these nonlinear transport properties by showing that MWNTs eliminate die swell in our nanocomposites, an effect crucial for their processing. PMID:15273745

  16. Characterization of the effects of x-ray irradiation on the hierarchical structure and mechanical properties of human cortical bone

    Energy Technology Data Exchange (ETDEWEB)

    Barth, Holly; Zimmermann, Elizabeth; Schaible, Eric; Tang, Simon; Alliston, Tamara; Ritchie, Robert

    2011-08-19

    Bone comprises a complex structure of primarily collagen, hydroxyapatite and water, where each hierarchical structural level contributes to its strength, ductility and toughness. These properties, however, are degraded by irradiation, arising from medical therapy or bone-allograft sterilization. We provide here a mechanistic framework for how irradiation affects the nature and properties of human cortical bone over a range of characteristic (nano to macro) length-scales, following x-­ray exposures up to 630 kGy. Macroscopically, bone strength, ductility and fracture resistance are seen to be progressively degraded with increasing irradiation levels. At the micron-­scale, fracture properties, evaluated using in-situ scanning electron microscopy and synchrotron x-ray computed micro-tomography, provide mechanistic information on how cracks interact with the bone-matrix structure. At sub-micron scales, strength properties are evaluated with in-situ tensile tests in the synchrotron using small-/wide-angle x-ray scattering/diffraction, where strains are simultaneously measured in the macroscopic tissue, collagen fibrils and mineral. Compared to healthy bone, results show that the fibrillar strain is decreased by ~40% following 70 kGy exposures, consistent with significant stiffening and degradation of the collagen. We attribute the irradiation-­induced deterioration in mechanical properties to mechanisms at multiple length-scales, including changes in crack paths at micron-­scales, loss of plasticity from suppressed fibrillar sliding at sub-­micron scales, and the loss and damage of collagen at the nano-­scales, the latter being assessed using Raman and Fourier-Transform-Infrared spectroscopy and a fluorometric assay.

  17. Effectiveness of platelet-rich plasma as an adjunctive material to bone graft: a systematic review and meta-analysis of randomized controlled clinical trials.

    Science.gov (United States)

    Pocaterra, A; Caruso, S; Bernardi, S; Scagnoli, L; Continenza, M A; Gatto, R

    2016-08-01

    The use of platelet-rich plasma (PRP) has become a strategic therapy in tissue regeneration medicine. PRP represents a good source of growth factors. Due to this property, it has been considered a reliable adjunctive material in bone augmentation procedures, such as the sinus lift technique. The aim of this review was to assess the scientific evidence on the effectiveness of PRP as an adjunctive material in the sinus floor elevation technique. The following databases were searched for relevant published studies: Medline, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, CINAHL, Science Direct, ISI Web of Knowledge, and SCOPUS. Only randomized controlled clinical trials comparing a group receiving PRP as an adjunctive material to a control group without PRP, involving adult human subjects (age >18 years) with no systemic disease, were included. Of the studies identified, only one reported a significant difference in bone augmentation in favour of the adjunctive use of PRP, while four studies did not find any significant difference. None of the studies included reported a significant difference in the implant survival rate. Further randomized clinical trials are needed to clarify the effectiveness of adjunctive PRP. PMID:26987695

  18. Bone plate composed of a ternary nano-hydroxyapatite/polyamide 66/glass fiber composite: biomechanical properties and biocompatibility.

    Science.gov (United States)

    Qiao, Bo; Li, Jidong; Zhu, Qingmao; Guo, Shuquan; Qi, Xiaotong; Li, Weichao; Wu, Jun; Liu, Yang; Jiang, Dianming

    2014-01-01

    An ideal bone plate for internal fixation of bone fractures should have good biomechanical properties and biocompatibility. In this study, we prepared a new nondegradable bone plate composed of a ternary nano-hydroxyapatite/polyamide 66/glass fiber (n-HA/PA66/GF) composite. A breakage area on the n-HA/PA66/GF plate surface was characterized by scanning electron microscopy. Its mechanical properties were investigated using bone-plate constructs and biocompatibility was evaluated in vitro using bone marrow-derived mesenchymal stem cells. The results confirmed that adhesion between the n-HA/PA66 matrix and the glass fibers was strong, with only a few fibers pulled out at the site of breakage. Fractures fixed by the n-HA/PA66/GF plate showed lower stiffness and had satisfactory strength compared with rigid fixation using a titanium plate. Moreover, the results with regard to mesenchymal stem cell morphology, MTT assay, Alizarin Red S staining, enzyme-linked immunosorbent assay, and reverse transcription polymerase chain reaction for alkaline phosphatase and osteocalcin showed that the n-HA/PA66/GF composite was suitable for attachment and proliferation of mesenchymal stem cells, and did not have a negative influence on matrix mineralization or osteogenic differentiation of mesenchymal stem cells. These observations indicate that the n-HA/PA66/GF plate has good biomechanical properties and biocompatibility, and may be considered a new option for internal fixation in orthopedic surgery. PMID:24669191

  19. The effect of unsaturated fatty acid and triglyceride oil addition on the mechanical and antibacterial properties of acrylic bone cements.

    Science.gov (United States)

    Persson, Cecilia; Robert, Elise; Carlsson, Elin; Robo, Céline; López, Alejandro; Godoy-Gallardo, Maria; Ginebra, Maria-Pau; Engqvist, Håkan

    2015-09-01

    Acrylic bone cements have an elastic modulus several times higher than the surrounding trabecular bone. This has been hypothesized to contribute to certain clinical complications. There are indications that the addition of specific fatty acids and triglyceride oils may reduce the elastic modulus of these types of cements. Some of these additives also appear to have inherent antibiotic properties, although this has never been evaluated in bone cements. In this study, several types of fatty acids and triglyceride oils were evaluated for use in acrylic bone cements. Their mechanical properties were evaluated under uniaxial compression testing and selected cements were then further characterized in terms of microstructure, handling and antibacterial properties using scanning electron microscopy, polymerization temperature measurements, agar diffusion tests and bactericidal activity assays of cement extracts. It was found that any of the evaluated fatty acids or triglyceride oils could be used to tailor the stiffness of acrylic bone cements, although at varying concentrations, which also depended on the type of commercial base cement used. In particular, the addition of very small amounts of linoleic acid (agar diffusion test as well as demonstrating 100% bactericidal activity against the same strain. PMID:25876889

  20. Frequency-dependent dynamic effective properties of porous materials

    Institute of Scientific and Technical Information of China (English)

    Peijun Wei; Zhuping Huang

    2005-01-01

    The frequency-dependent dynamic effective properties (phase velocity, attenuation and elastic modulus) of porous materials are studied numerically. The coherent plane longitudinal and shear wave equations, which are obtained by averaging on the multiple scattering fields, are used to evaluate the frequency-dependent dynamic effective properties of a porous material. It is found that the prediction of the dynamic effective properties includes the size effects of voids which are not included in most prediction of the traditional static effective properties. The prediction of the dynamic effective elastic modulus at a relatively low frequency range is compared with that of the traditional static effective elastic modulus, and the dynamic effective elastic modulus is found to be very close to the Hashin-Shtrikman upper bound.

  1. Genetics of the Steller's Sea Cow (Hydrodamalis gigas): A Study of Ancient Bone Material

    Science.gov (United States)

    Crerar, Lorelei D.

    Georg Wilhelm Steller was born 100 years before Darwin in 1709 and he was part of a vast exploration fifty years before Lewis and Clark explored America. Steller was important to the study of marine mammals because he was the only naturalist to see and describe the great northern sea cow ( Hydrodamalis gigas). Knowledge of an extinct population can be used to aid the conservation of a current population. Extraction of DNA from this extinct animal was performed in order to determine the population structure of the Steller's sea cow. A test was also developed that can definitively state whether or not a random bone sample came from H. gigas. This test could be used by the Fish and Wildlife Service (FWS) and the National Oceanic and Atmospheric Administration (NOAA) to examine material distributed in the North Pacific to determine whether samples are legally traded extinct Steller's sea cow or illegally traded extant marine mammal species protected under the Marine Mammal Protection Act (MMPA).

  2. On the reliability of microstructural models of trabecular bone with tissue properties from nanoindentation for bone quality assessment

    Czech Academy of Sciences Publication Activity Database

    Jiroušek, Ondřej; Zlámal, Petr

    Praha : Czech Technical University, Faculty of Transportation Sciences, 2012 - (Jiroušek, O.; Kytýř, D.), s. 111-114 ISBN 978-80-01-05062-0. [Bilateral Czech/German Symposium /13./. Telč (CZ), 05.06.2012-08.06.2012] R&D Projects: GA ČR(CZ) GAP105/10/2305 Institutional support: RVO:68378297 Keywords : finite element method * micro-CT * microstructural models * trabecular bone Subject RIV: FI - Traumatology, Orthopedics

  3. Polymers for electricity and electronics materials, properties, and applications

    CERN Document Server

    Drobny, Jiri George

    2011-01-01

    The comprehensive, practical book that explores the principles, properties, and applications of electrical polymers The electrical properties of polymers present almost limitless possibilities for industrial research and development, and this book provides an in-depth look at these remarkable molecules. In addition to traditional applications in insulating materials, wires, and cables, electrical polymers are increasingly being used in a range of emerging technologies. Presenting a comprehensive overview of how electrical polymers function and how they can be applied in the elec

  4. Structure and properties of sintered tool gradient materials

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2010-12-01

    Full Text Available Purpose: The main objective of the presented is to elaborate the fabrication technology of novel sintered tool gradient materials on the basis of hard wolfram carbide phase with cobalt binding phase, and to carry out research studies on the structure and properties of the newly elaborated sintered tool gradient materials.Design/methodology/approach: The following research studies have been carried out to elaborate a new group of sintered tool gradient materials, wolfram carbide with cobalt matrix, to elaborate their fabrication technology and to determine their structure and properties: a fabrication technology of mixtures and the formation technology of wolfram carbide gradient materials with cobalt matrix WC-Co was applied and elaborated; sintering conditions were selected experimentally: time, temperature and sintering atmosphere as well as isostatic condensation, ensuring the best structure and properties; phase and chemical composition of the sintered gradient WC-Co materials was determined using EDX, EBSD methods and qualitative X-ray analysis; the structure of sintered gradient WC-Co materials was investigated using scanning microscopy and transmission electron microscopy; mechanical and physical properties of sintered gradient WC-Co materials was determined: porosity, density, hardness, resistance to abrasive wear, resistance to brittle cracking.Findings: The presented research results confirm that the newly elaborated technology of powder metallurgy, which consists in sequential coating of the moulding with layers having the increasing content of carbides and decreasing concentration of cobalt, and then sintering such a compact, ensures the acquisition of the required structure and properties, including the resistance to cracking and abrasive wear of tool gradient materials, due to earned high hardness and resistance to abrasive wear on the surface as well as high resistance to cracking in the core of the materials fabricated in such a

  5. Fabrication, properties, and tritium recovery from solid breeder materials

    International Nuclear Information System (INIS)

    The breeding blanket is a key component of the fusion reactor because it directly involves tritium breeding and energy extraction, both of which are critical to development of fusion power. The lithium ceramics continue to show promise as candidate breeder materials. This promise was recognized by the International Thermonuclear Experimental Reactor (ITER) design team in its selection of ceramics as the first option for the ITER breeder material. Blanket design studies have indicated properties in the candidate materials data base that need further investigation. Current studies are focusing on tritium release behavior at high burnup, changes in thermophysical properties with burnup, compatibility between the ceramic breeder and beryllium multiplier, and phase changes with burnup. Laboratory and in-reactor tests, some as part of an international collaboration for development of ceramic breeder materials, are underway. 133 refs., 1 fig

  6. Fibrous random materials: From microstructure to macroscopic properties

    Science.gov (United States)

    Yazdchi, K.; Luding, S.

    2013-06-01

    Fibrous porous materials are involved in a wide range of applications including composite materials, fuel cells, heat exchangers and (biological)filters. Fluid flow through these materials plays an important role in many engineering applications and processes, such as textiles and paper manufacturing or transport of (under)ground water and pollutants. While most porous materials have complex geometry, some can be seen as two-dimensional particulate/fibrous systems, in which we introduce several microscopic quantities, based on Voronoi and Delaunay tessellations, to characterize their microstructure. In particular, by analyzing the topological properties of Voronoi polygons, we observe a smooth transition from disorder to order, for increasing packing fraction. Using fully resolved finite element (FE) simulations of Newtonian, incompressible fluid flow perpendicular to the fibres, the macroscopic permeability is calculated in creeping flow regimes. The effect of fibre arrangement and local crystalline regions on the macroscopic permeability is discussed and the macroscopic property is linked to the microscopic structural quantities.

  7. Handbook on dielectric and thermal properties of microwaveable materials

    CERN Document Server

    Komarov, Vyacheslav V

    2012-01-01

    The application of microwave energy for thermal processing of different materials and substances is a rapidly growing trend in modern science and engineering. In fact, optimal design work involving microwaves is impossible without solid knowledge of the properties of these materials. Here s a practical reference that collects essential data on the dielectric and thermal properties of microwaveable materials, saving you countless hours on projects in a wide range of areas, including microwave design and heating, applied electrodynamics, food science, and medical technology. This unique book provides hard-to-find information on complex dielectric permittivity of media at industrial, scientific, and medical frequencies (430 MHz, 915MHz, 2.45GHz, 5.8 GHz, and 24.125GHz). Written by a leading expert in the field, this authoritative book does an exceptional job at presenting critical data on various materials and explaining what their key characteristics are concerning microwaves.

  8. Synthesis, Properties and Mineralogy of Important Inorganic Materials

    CERN Document Server

    Warner, Terence E

    2010-01-01

    Intended as a textbook for courses involving preparative solid-state chemistry, this book offers clear and detailed descriptions on how to prepare a selection of inorganic materials that exhibit important optical, magnetic and electrical properties, on a laboratory scale. The text covers a wide range of preparative methods and can be read as separate, independent chapters or as a unified coherent body of work. Discussions of various chemical systems reveal how the properties of a material can often be influenced by modifications to the preparative procedure, and vice versa. References to miner

  9. Material Property Characterization of AS4/VRM-34 Textile Laminates

    Science.gov (United States)

    Grenoble, Ray W.; Johnston, William M

    2013-01-01

    Several material properties (modulus, strengths, and fracture toughness) of a textile composite have been evaluated to provide input data to analytical models of Pultruded Rod Stiffened Efficient Unitized Structure (PRSEUS). The material system is based on warp-knitted preforms of AS4 carbon fibers and VRM-34 epoxy resin, which have been processed via resin infusion and oven curing. Tensile, compressive, shear, and fracture toughness properties have been measured at ambient and elevated temperatures. All specimens were tested in as-fabricated (dry) condition. Specimens were tested with and without through-thickness stitching.

  10. INVESTIGATION OF TRIBOLOGICAL PROPERTIES CuSn10 BEARING MATERIAL

    Directory of Open Access Journals (Sweden)

    Bekir Sadık ÜNLÜ

    2005-01-01

    Full Text Available Bronzes which copper based alloys is widely used because of properties physical, thermal and tribological as journal bearing material. This material that has tribological performance good conclusions gives at journal bearings. In this study, CuSn10 bronze that were manufactured journal bearings friction and wear properties has been examined and compared. SAE 1050 steel shaft has been used as counter abrader. Experiments have been carried out 10 N and 20 N loads, 750 and 1500 rpm, dry and lubricated conditions by using radial journal bearing wear test rig. As a results, high friction coefficient and weigh loss have been obtained at dry condition more than lubricated condition.

  11. Reflector and Shield Material Properties for Project Prometheus

    Energy Technology Data Exchange (ETDEWEB)

    J. Nash

    2005-11-02

    This letter provides updated reflector and shield preliminary material property information to support reactor design efforts. The information provided herein supersedes the applicable portions of Revision 1 to the Space Power Program Preliminary Reactor Design Basis (Reference (a)). This letter partially answers the request in Reference (b) to provide unirradiated and irradiated material properties for beryllium, beryllium oxide, isotopically enriched boron carbide ({sup 11}B{sub 4}C) and lithium hydride. With the exception of {sup 11}B{sub 4}C, the information is provided in Attachments 1 and 2. At the time of issuance of this document, {sup 11}B{sub 4}C had not been studied.

  12. Characterization of Viscoelastic Properties of Polymeric Materials Through Nanoindentation

    Science.gov (United States)

    Odegard, G. M.; Bandorawalla, T.; Herring, H. M.; Gates, T. S.

    2003-01-01

    Nanoindentation is used to determine the dynamic viscoelastic properties of six polymer materials. It is shown that varying the harmonic frequency of the nanoindentation does not have any significant effect on the measured storage and loss moduli of the polymers. Agreement is found between these results and data from DMA testing of the same materials. Varying the harmonic amplitude of the nanoindentation does not have a significant effect on the measured properties of the high performance resins, however, the storage modulus of the polyethylene decreases as the harmonic amplitude increases. Measured storage and loss moduli are also shown to depend on the density of the polyethylene.

  13. Bioactive glass-polymer composite for experimental bone reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Aho, A.J.; Tirri, T.; Strandberg, N.; Jaakkola, T.; Naerhi, T.; Kukkonen, J. [Turku Univ. (Finland). Biomaterials Project of Turku; Seppaelae, J.; Rich, J. [Helsinki Univ. of Technology, Espoo (Finland). Dept. of Chemical Engineering

    2001-07-01

    Thermoplastic composite of bioactive glass (S53P4) and copolymer of lactones (Glepron) can be used as liquid, injectable or paste like form, as solid plugs or thin membranes for filling bone defects. This bone substitute is bioactive, osteoconductive and biocompatible resulting in bone bonding contacts between glass granules and bone in defects on the distal femur and ulna of experimental animals. Properties of the material can be adjusted by polymer chemistry. (orig.)

  14. Electronic transport properties of few-layer graphene materials

    OpenAIRE

    Russo, S.; Craciun, M. F.; Khodkov, T.; Koshino, M.; Yamamoto, M.; Tarucha, S.

    2011-01-01

    Since the discovery of graphene -a single layer of carbon atoms arranged in a honeycomb lattice - it was clear that this truly is a unique material system with an unprecedented combination of physical properties. Graphene is the thinnest membrane present in nature -just one atom thick- it is the strongest material, it is transparent and it is a very good conductor with room temperature charge mobilities larger than the typical mobilities found in silicon. The significance played by this new m...

  15. Nanomechanical and phononic properties of structured soft materials

    OpenAIRE

    Gomopoulos, Nikolaos

    2009-01-01

    Significant interest in nanotechnology, is stimulated by the fact that materials exhibit qualitative changes of properties when their dimensions approach ”finite-sizes”. Quantization of electronic, optical and acoustic energies at the nanoscale provides novel functions, with interests spanning from electronics and photonics to biology. The present dissertation involves the application of Brillouin light scattering (BLS) to quantify and utilize material displacementsrnfor probing phononics and e...

  16. Dosimetric properties of natural quartz grains extracted from fired materials

    DEFF Research Database (Denmark)

    Bluszcz, A.; Bøtter-Jensen, L.

    1995-01-01

    The paper describes an examination of the dosimetric properties of natural quartz grains extracted from ancient fired materials. Eleven samples of different origin were tested for their TL and GLSL (green light stimulated luminescence) sensitivities within the mGy dose range. Very promising results...... quartz grains from selected materials could be used for the dosimetry of environmental gamma radiation for the purposes of paleodosimetric dating methods as well as for accident dosimetry....

  17. Textile Materials with New Properties Used for Confections Manufacturing

    OpenAIRE

    Neacşu A. N.; Madar A.

    2009-01-01

    The quality of textile clothing depends on the quality of prime materials and also on the technology used; this must ensure a balance between transferred heat, resulted humidity and human and environmental thermal demands, all this bringing about physiological comfort. In order to meet consumers’ demands regarding the production of products which are easy to maintain and have high hygiene properties, new prime materials are searched, with a view to ensuring a wide range of clothing. Taking in...

  18. Design of materials Configurations for enhanced phononic and electronic properties

    OpenAIRE

    Daraio, Chiara

    2006-01-01

    The discovery of novel nonlinear dynamic and electronic phenomena is presented for the specific cases of granular materials and carbon nanotubes. This research was conducted for designing and constructing optimized macro-, micro- and nano-scale structural configurations of materials, and for studying their phononic and electronic behavior. Variation of composite arrangements of granular elements with different elastic properties in a linear chain-of-sphere, Y-junction or 3-D configurations le...

  19. Thermomechanical Properties of Corundum—Mullite—Zirconia Materials

    Institute of Scientific and Technical Information of China (English)

    ZHONGXiangchong; SUNGengcheng

    1998-01-01

    The mechanical properties at elevated tempera-tures of corundum-mullite materials and the effects of zirconia and titania additions have been investi-gated.The results are correlated with changes in microstructure,Based on the results of these investi-gations ,reaction-sintered corundum-mullite-zirco-nia materials with improved hot strength and ther-mal shock resistance have been developed for refractor-ries usage.

  20. Near-Field Microwave Microscopy of Materials Properties

    OpenAIRE

    Anlage, Steven M.; Steinhauer, D. E.; Feenstra, B. J.; Vlahacos, C. P.; Wellstood, F. C.

    2000-01-01

    Near-field microwave microscopy has created the opportunity for a new class of electrodynamics experiments of materials. Freed from the constraints of traditional microwave optics, experiments can be carried out at high spatial resolution over a broad frequency range. In addition, the measurements can be done quantitatively so that images of microwave materials properties can be created. We review the five major types of near-field microwave microscopes and discuss our own form of microscopy ...

  1. Overview of European Community (Activity 3) work on materials properties of fast reactor structural materials

    International Nuclear Information System (INIS)

    The Fast Reactor Coordinating Committee set up in 1974 the Working Group Codes and Standards, and organized its work into four main activities: Manufacturing standards, Structural analysis, Materials and Classification of components. The main purpose of materials activity is to compare and contrast existing national specifications and associated properties relevant to structural materials in fast reactors. Funds are available on a yearly basis for tasks to be carried out through Study Contracts. At present about four Study Contract Reports are prepared each year

  2. Background material properties of selected silicone potting compounds and raw materials for their substitutes

    Energy Technology Data Exchange (ETDEWEB)

    Flowers, G.L.; Switzer, S.T.

    1978-05-01

    Since Dow Corning discontinued production of 93-119, 93-120, 93-122, Pantex joined with the Lawrence Livermore Laboratory to develop substitutes for these materials. Raw materials chosen for this project include Sylgard 184, Sylgard 186, Q3-6527 Dielectric Gel, Q3-6559 Accelerator, DC 1107 and Cab-o-Sil MS-75. This report deals with physical and chemical properties of these materials.

  3. Differences in Bone Quality between High versus Low Turnover Renal Osteodystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Daniel S. [University of Kentucky, Lexington; Pienkowski, David [University of Kentucky, Lexington; Faugere, Marie-Claude [Albert B. Chandler Medical Center; Malluche, Hartmut H. [Albert B. Chandler Medical Center

    2012-01-01

    Abnormal bone turnover is common in chronic kidney disease (CKD), but its effects on bone quality remain unclear. This study sought to quantify the relationship between abnormal bone turnover and bone quality. Iliac crest bone biopsies were obtained from CKD-5 patients on dialysis with low (n=18) or high (n=17) turnover, and from volunteers (n=12) with normal turnover and normal kidney function. Histomorphometric methods were used to quantify the microstructural parameters; Fourier transform infrared spectroscopy and nanoindentation were used to quantify the material and mechanical properties in bone. Reduced mineral-to-matrix ratio, mineral crystal size, stiffness and hardness were observed in bone with high turnover compared to bone with normal or low turnover. Decreased cancellous bone volume and trabecular thickness were seen in bone with low turnover compared to bone with normal or high turnover. Bone quality, as defined by its microstructural, material, and mechanical properties, is related to bone turnover. These data suggest that turnover related alterations in bone quality may contribute to the known diminished mechanical competence of bone in CKD patients, albeit from different mechanisms for bone with high (material abnormality) vs. low (microstructural alteration) turnover. The present findings suggest that improved treatments for renal osteodystrophy should seek to avoid low or high bone turnover and aim for turnover rates as close to normal as possible.

  4. Standard Guide for Identification of Fibers, Fillers, and Core Materials in Computerized Material Property Databases

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1992-01-01

    1.1 This guide establishes the essential and desirable elements of data required for the identification in computerized material property databases of fibers, fillers, and core materials used in composite materials. A recommended format for entry of these fields into a computerized database is provided. Examples of the application of this guide are also included. 1.2 The recommended format described in this guide is suggested for use in recording data in a database, which is different from contractural reporting of actual test results. The latter type of information is described in materials specifications shown in business transactions and is subject to agreement between vendor and purchaser. 1.3 The materials covered by this guide include fibers, both continuous and discontinuous, and fillers of various geometries which are used as reinforcements in composite materials, as well as core materials used in sandwich composites. Cores may be foam, honeycomb, or naturally occurring materials such as balsa wood....

  5. Characterization of the interaction between therapeutical carbon ions and bone-like materials and related impact on treatment planning

    International Nuclear Information System (INIS)

    Radiotherapy is one of the most common and effective therapies for cancer. The treatment planning system for ions TRiP98 was developed at GSI, Darmstadt. In TRiP98, the interaction between primary radiation and tissue is modeled from experimental data measured in water and rescaled to other tissue. This approximation is not accurate enough for biological materials whose elemental composition besides density deviates significantly from water. The nuclear attenuation of carbon beams in bone-like materials was measured and an estimation of the fragmentation cross section was done. In parallel, the dose profile inhomogeneity predicted by TRiP98 at the interface between water and bones was investigated and measured at HIT (Heidelberg). A 3D treatment plan was delivered in a water phantom equipped with bone targets. Pin-point ionization chambers and X-ray dosimetric films were used for measuring the dose at different positions. As a further step, the measured cross sections of carbon ions in bone have been implemented in TRiP98. The comparison of the dose profiles calculated with the standard and benchmarked versions of the treatment planning will give an estimate of the improvement.

  6. Tribological and Wear Properties of Multi-Layered Materials

    Directory of Open Access Journals (Sweden)

    V. Bria

    2011-09-01

    Full Text Available The usage of fabrics as reinforcements in composites is spreading due to fabrics’ properties. The use of fabrics allows obtaining of sinuous surfaces, for instance, unlike the use of prepregs. Using fabrics as reinforcements it is also possible to obtain laminate-like materials having the same matrix in all their volume. In the case of pre-pregs usage always it is necessary to discuss about the bonding between individual plies. For this study eight materials were formed. The forming method consisted in placing the pre-polymer imbued fabric pieces into a mould to obtain plates of composites. Two types of fabric were used: one simple type of untwisted tows of carbon fibres and the second one simple type of alternated untwisted tows of carbon and aramide fibres. Both fabrics were prepared in order to ensure the matrix adherence. The polymer matrix is realised from epoxy system EPIPHEN RE 4020 / EPIPHEN DE 4020 filled with clay and talc in equal amounts of 5% (weight ratio. The use of clay and talc were meant to improve the thermal dimensional stability of final materials. Tribological properties of formed materials were studied using pin-on-disk method with steel disk and pins made of materials. Both orientation of reinforcement fibres relative to friction direction were taken into account. Results are encouraging further studies in order to identify the best solution of forming a multi-component material with more than one designable property.

  7. The synthesis and properties of nanoscale ionic materials

    KAUST Repository

    Rodriguez, Robert Salgado

    2010-02-17

    In this article we discuss the effect of constituents on structure, flow, and thermal properties of nanoscale ionic materials (NIMs). NIMs are a new class of nanohybrids consisting of a nanometer-sized core, a charged corona covalently attached to the core, and an oppositely charged canopy. The hybrid nature of NIMs allows for their properties to be engineered by selectively varying their components. The unique properties associated with these systems can help overcome some of the issues facing the implementation of nanohybrids to various commercial applications, including carbon dioxide capture,water desalinization and as lubricants. Copyright © 2010 John Wiley & Sons, Ltd.

  8. Effect of Nutrition on Biomechanical Properties of Bone in Laying Hens and Broilers

    OpenAIRE

    Osman Olgun

    2014-01-01

    Leg problems have caused significant economic losses in poultry sector. Bone quality and strong is related to nutrition. In this review, effects of nutrition on bone strength are given to laying hens and broilers. For this, effects of some minerals and feed additives on bone quality were reviewed. Calcium, phosphorus, boron and some feed additives in feeding of hens and broilers are important to strong bone. In addition, the form of calcium resources must be considered in laying hens.

  9. Thermoelectric properties in phase-separated half-Heusler materials

    OpenAIRE

    Krez, Julia

    2014-01-01

    The conversion of dissipated heat into electricity is the basic principle of thermoelectricity. In this context, half-Heusler (HH) compounds are promising thermoelectric (TE) materials for waste heat recovery. They meet all the requirements for commercial TE applications, ranging from good efficiencies via environmentally friendliness to being low cost materials. This work focused on the TE properties of Ti0.3Zr0.35Hf0.35NiSn-based HH materials. This compound undergoes an intrinsic phase sepa...

  10. Evaluation of Water Resistance and Diffusion Properties of Paint Materials

    Directory of Open Access Journals (Sweden)

    J. Drchalová

    2001-01-01

    Full Text Available A simple method is presented for evaluating the water-proofness quality of paints on lining materials. The method is based on measuring the integral capillarity in dependence on time, and then comparing this value to the value determined for the basic lining material. Measurements of the effective water vapor permeability then provide information on the risk of condensation which may increase after applying the paint. A practical application of the method is performed with four Karlocolor paints on glass concrete substrates. All the Karlocolor paints are found to be very effective materials for driven rain protection. The diffusion properties of all the paints are found to be excellent.

  11. Controlling dynamic mechanical properties and degradation of composites for bone regeneration by means of filler content

    NARCIS (Netherlands)

    Barbieri, Davide; de Bruijn, Joost D.; Luo, Xiaoman; Fare, Silvia; Grijpma, Dirk W.; Yuan, Huipin

    2013-01-01

    Bone tissue is a dynamic composite system that adapts itself, in response to the surrounding daily (cyclic) mechanical stimuli, through an equilibrium between growth and resorption processes. When there is need of synthetic bone grafts, the biggest issue is to support bone regeneration without causi

  12. Calibration of hyperelastic material properties of the human lumbar intervertebral disc under fast dynamic compressive loads.

    Science.gov (United States)

    Wagnac, Eric; Arnoux, Pierre-Jean; Garo, Anaïs; El-Rich, Marwan; Aubin, Carl-Eric

    2011-10-01

    Under fast dynamic loading conditions (e.g. high-energy impact), the load rate dependency of the intervertebral disc (IVD) material properties may play a crucial role in the biomechanics of spinal trauma. However, most finite element models (FEM) of dynamic spinal trauma uses material properties derived from quasi-static experiments, thus neglecting this load rate dependency. The aim of this study was to identify hyperelastic material properties that ensure a more biofidelic simulation of the IVD under a fast dynamic compressive load. A hyperelastic material law based on a first-order Mooney-Rivlin formulation was implemented in a detailed FEM of a L2-L3 functional spinal unit (FSU) to represent the mechanical behavior of the IVD. Bony structures were modeled using an elasto-plastic Johnson-Cook material law that simulates bone fracture while ligaments were governed by a viscoelastic material law. To mimic experimental studies performed in fast dynamic compression, a compressive loading velocity of 1 m/s was applied to the superior half of L2, while the inferior half of L3 was fixed. An exploratory technique was used to simulate dynamic compression of the FSU using 34 sets of hyperelastic material constants randomly selected using an optimal Latin hypercube algorithm and a set of material constants derived from quasi-static experiments. Selection or rejection of the sets of material constants was based on compressive stiffness and failure parameters criteria measured experimentally. The two simulations performed with calibrated hyperelastic constants resulted in nonlinear load-displacement curves with compressive stiffness (7335 and 7079 N/mm), load (12,488 and 12,473 N), displacement (1.95 and 2.09 mm) and energy at failure (13.5 and 14.7 J) in agreement with experimental results (6551 ± 2017 N/mm, 12,411 ± 829 N, 2.1 ± 0.2 mm and 13.0 ± 1.5 J respectively). The fracture pattern and location also agreed with experimental results. The simulation performed with

  13. Raman spectroscopy detects deterioration in biomechanical properties of bone in a glucocorticoid-treated mouse model of rheumatoid arthritis

    Science.gov (United States)

    Maher, Jason R.; Takahata, Masahiko; Awad, Hani A.; Berger, Andrew J.

    2011-08-01

    Although glucocorticoids are frequently prescribed for the symptomatic management of inflammatory disorders such as rheumatoid arthritis, extended glucocorticoid exposure is the leading cause of physician-induced osteoporosis and leaves patients at a high risk of fracture. To study the biochemical effects of glucocorticoid exposure and how they might affect biomechanical properties of the bone, Raman spectra were acquired from ex vivo tibiae of glucocorticoid- and placebo-treated wild-type mice and a transgenic mouse model of rheumatoid arthritis. Statistically significant spectral differences were observed due to both treatment regimen and mouse genotype. These differences are attributed to changes in the overall bone mineral composition, as well as the degree of phosphate mineralization in tibial cortical bone. In addition, partial least squares regression was used to generate a Raman-based prediction of each tibia's biomechanical strength as quantified by a torsion test. The Raman-based predictions were as accurate as those produced by microcomputed tomography derived parameters, and more accurate than the clinically-used parameter of bone mineral density. These results suggest that Raman spectroscopy could be a valuable tool for monitoring bone biochemistry in studies of bone diseases such as osteoporosis, including tests of drugs being developed to combat these diseases.

  14. Preparation and characterization of chitosan/nano-hydroxyapatite composite used as bone substitute materials

    Institute of Scientific and Technical Information of China (English)

    Zhang Li; Li Yubao; Zhou Gang; Wu Lan; Mu Yuanhua; Yang Zheng

    2007-01-01

    Chitosan/nano-hydroxyapatite composites with different weight ratios were prepared through a co-precipitation method using Ca(OH)2, H3PO4 and chitosan as starting materials. The properties of these composites were characterized by means of TEM, IR, XRD, TGA, bum-out tests and universal matertial testing machine. The results showed that the HA synthesized here was poorly crystalline carbonated nanometer crystals and dispersed uniformly in chitosan phase and there was no phase-separation between the two phases. The addition of n-HA resulted in a decrease of decomposing temperature of chitosan. Because of the interactions between chitosan and n-HA, the mechanical properties of these composites were improved, and the maximum value of the compressive strength was measured to be about 120MPa corresponding to the chitosan/n-HA composite with a weight ratio of 30/70.

  15. A new bone imaging agent, 99Tcm-BIPrDP, its preparation and biological properties

    International Nuclear Information System (INIS)

    Objective: To investigate the feasibility of 99Tcm-1-hydroxy-3-(2-butyl-1H-imidazol-1-yl) propane-1, 1-diphosphonic acid (BIPrDP) as a new bone imaging agent. Methods: BIPrDP was synthesized by three steps from the raw material 2-butyl-1H-imidazole. 99Tcm-BIPrDP were prepared with mixed BIPrDP (50 mg/ml, 100 μl) and freshly eluted Na99TcmO4 (37.0 MBq) in the presence of the reducing agent SnCl2 (1 rng/ml, 100 μl) at boiling temperature for 30 min. The labeling yield and stability of 99Tcm-BIPrDP were measured with TLC. Partition coefficient in octanol-water and plasma protein binding ratio to human heparin anticoagulation plasma of 99Tcm-BIPrDP was checked. ICR mice were sacrificed at 5, 10, 15, 30, 60, 120 and 240 min after tail vein injection of 0.2 ml (7.4 MBq) freshly prepared 99Tcm-BIPrDP.Samples of blood, heart, liver, spleen, lung, kidney, bone, muscle, gonad, intestine, stomach and brain were taken, weighed and the gamma counts measured. The biodistribution of the radiolabeled compound in different organs was calculated and expressed as % ID/g. Bone-to-organ uptake ratios were calculated by the % ID/g values. The kinetics of blood clearance was calculated. Bone imaging was performed in New Zealand rabbit after intravenous injection of 99Tcm-BIPrDP. One-way analysis of variance was used to analyze the % ID/g at different times points. Results: Radiolabeling yield of 99Tcm-BIPrDP was more than 95% and the labeled complex was stable at least up to 6 h in vitro. The octanol-water partition coefficients (log P) for 99Tcm-BIPrDP were-2.396 ± 0.035 and-2.242 ± 0.025 at pH values of 7.0 and 7.4, respectively. The plasma protein binding rate of 99Tcm-BIPrDP was (47.07 ± 0.05)%. The bone uptake of 99Tcm-BIPrDP in mice reached a maximum of 19.20 % ID/g at 30 min after injection, and this high level of uptake persisted 4 h later at 18.98 % ID/g. Kidney uptake was highest among all the non-target organs,but decreased from 24.50 % ID/g at 5 min to 5.22 % ID/g at 4 h

  16. Phase change memory materials, composition, structure and properties

    Czech Academy of Sciences Publication Activity Database

    Frumar, M.; Frumarová, Božena; Wágner, T.; Přikryl, J.; Hrdlička, M.

    Darwin : Charles Darwin University, 2006. ID8-ID8. [International Conference on Optical and Optoelectronic Properties of Materials and Applications 2006. 16.06.2006-20.06.2006, Darwin ] R&D Projects: GA ČR GA203/06/0627 Keywords : phase change memory Subject RIV: CA - Inorganic Chemistry

  17. Food material properties and early hominin processing techniques.

    Science.gov (United States)

    Zink, Katherine D; Lieberman, Daniel E; Lucas, Peter W

    2014-12-01

    Although early Homo is hypothesized to have used tools more than australopiths to process foods prior to consumption, it is unknown how much the food processing techniques they used altered the material properties of foods, and therefore the masticatory forces they generated, and how well they were able to comminute foods. This study presents experimental data on changes to food material properties caused by mechanical tenderization (pounding with a stone tool) and cooking (dry roasting) of two foods likely to have been important components of the hominin diet: meat and tubers. Mechanical tenderization significantly decreased tuber toughness by 42%, but had no effect on meat toughness. Roasting significantly decreased several material properties of tubers correlated with masticatory effort including toughness (49%), fracture stress (28%) and elastic modulus (45%), but increased the toughness (77%), fracture stress (50%-222%), and elastic modulus of muscle fibers in meat (308%). Despite increasing many material properties of meat associated with higher masticatory forces, roasting also decreased measured energy loss by 28%, which likely makes it easier to chew. These results suggest that the use of food processing techniques by early Homo probably differed for meat and tubers, but together would have reduced masticatory effort, helping to relax selection to maintain large, robust faces and large, thickly enameled teeth. PMID:25439707

  18. Learning to Apply Models of Materials While Explaining Their Properties

    Science.gov (United States)

    Karpin, Tiia; Juuti, Kalle; Lavonen, Jari

    2014-01-01

    Background: Applying structural models is important to chemistry education at the upper secondary level, but it is considered one of the most difficult topics to learn. Purpose: This study analyses to what extent in designed lessons students learned to apply structural models in explaining the properties and behaviours of various materials.…

  19. Low temperature radiative properties of materials used in cryogenics

    Czech Academy of Sciences Publication Activity Database

    Musilová, Věra; Hanzelka, Pavel; Králík, Tomáš; Srnka, Aleš

    2005-01-01

    Roč. 45, č. 8 (2005), s. 529-536. ISSN 0011-2275 R&D Projects: GA AV ČR(CZ) IBS2065109 Keywords : structural materials * radiant properties * cryostats Subject RIV: BJ - Thermodynamics Impact factor: 0.762, year: 2005

  20. How to determine composite material properties using numerical homogenization

    DEFF Research Database (Denmark)

    Andreassen, Erik; Andreasen, Casper Schousboe

    2014-01-01

    Numerical homogenization is an efficient way to determine effective macroscopic properties, such as the elasticity tensor, of a periodic composite material. In this paper an educational description of the method is provided based on a short, self-contained Matlab implementation. It is shown how the...

  1. Mechanics of advanced materials analysis of properties and performance

    CERN Document Server

    Matveenko, Valery

    2015-01-01

    The last decades have seen a large extension of types of materials employed in various applications. In many cases these materials demonstrate mechanical properties and performance that vary significantly from those of their traditional counterparts. Such uniqueness is sought – or even specially manufactured – to meet increased requirements on modern components and structures related to their specific use. As a result, mechanical behaviors of these materials under different loading and environmental conditions are outside the boundaries of traditional mechanics of materials, presupposing development of new characterization techniques, theoretical descriptions and numerical tools. The book presents interesting examples of recent developments in this area. Among the studied materials are bulk metallic glasses, metamaterials, special composites, piezoelectric smart structures, nonwovens, etc.

  2. Effect of HMB and 2-Ox administered during pregnancy on bone properties in primiparous and multiparous minks (Neivison vison

    Directory of Open Access Journals (Sweden)

    Tomaszewska Ewa

    2015-12-01

    Full Text Available The aim of the study was to determine the mechanical and geometric properties as well as bone tissue density of long bones in primiparous and multiparous dams of minks supplemented with β-hydroxy β-methylbutyrate (HMB and/or 2-oxoketoglutarate (2-Ox during gestation. Powdered 2-Ox was given at the daily dosage of 0.4 g/kg b.w. separately or simultaneously with HMB, which was administered at the daily dosage of 0.02 g/kg b.w. The study demonstrates for the first time that administration of 2-Ox and/or HMB to dams markedly influences bone tissue density and the mechanical and geometrical properties of mother`s bones in minks. Moreover, it was demonstrated that the supplementation was more effective in the thoracic limb, which was comprehensively used in contrast to the pelvic limb. The mechanical parameters and bone tissue density significantly increased in the humerus in multiparous minks. Only such diet may provide satisfactory production results in the animals. Nutritional deficiencies occurring during pregnancies may trigger body`s own reserves to cover the bone mass increase in developing foetuses and support milk production. This can prevent regeneration of dams’ organisms, which negatively affects their reproductive performance. 2-Ox or HMB may be regarded as a protective metabolite when administered orally to minks, counteracting the negative influences of pregnancy and lactation periods on bones condition. Both simultaneous treatment with 2-Ox and HMB and their separate administration were equally effective.

  3. Material and Flexural Properties of Fiber-reinforced Rubber Concrete

    Science.gov (United States)

    Helminger, Nicholas P.

    The purpose of this research is to determine the material properties of rubber concrete with the addition of fibers, and to determine optimal mixture dosages of rubber and fiber in concrete for structural applications. Fiber-reinforced concrete and rubberized concrete have been researched separately extensively, but this research intends to combine both rubber and fiber in a concrete matrix in order to create a composite material, fiber-reinforced rubber concrete (FRRC). Sustainability has long been important in engineering design, but much of the previous research performed on sustainable concrete does not result in a material that can be used for practical purposes. While still achieving a material that can be used for structural applications, economical considerations were given when choosing the proportions and types of constituents in the concrete mix. Concrete mixtures were designed, placed, and tested in accordance with common procedures and standards, with an emphasis on practicality. Properties that were investigated include compressive strength, tensile strength, modulus of elasticity, toughness, and ductility. The basis for determining the optimal concrete mixture is one that is economical, practical, and exhibits ductile properties with a significant strength. Results show that increasing percentages of rubber tend to decrease workability, unit weight, compressive strength, split tensile strength, and modulus of elasticity while the toughness is increased. The addition of steel needle fibers to rubber concrete increases unit weight, compressive strength, split tensile strength, modulus of elasticity, toughness, and ductility of the composite material.

  4. Murine patellar tendon biomechanical properties and regional strain patterns during natural tendon-to-bone healing after acute injury

    OpenAIRE

    Gilday, Steven D.; Casstevens, E. Chris; Kenter, Keith; Jason T Shearn; David L Butler

    2013-01-01

    Tendon-to-bone healing following acute injury is generally poor and often fails to restore normal tendon biomechanical properties. In recent years, the murine patellar tendon (PT) has become an important model system for studying tendon healing and repair due to its genetic tractability and accessible location within the knee. However, the mechanical properties of native murine PT, specifically the regional differences in tissue strains during loading, and the biomechanical outcomes of natura...

  5. Moisture effect on mechanical properties of polymeric composite materials

    Science.gov (United States)

    Airale, A. G.; Carello, M.; Ferraris, A.; Sisca, L.

    2016-05-01

    The influence of moisture on the mechanical properties of fibre-reinforced polymer matrix composites (PMCs) was investigated. Four materials had been take into account considering: both 2×2-Twill woven carbon fibre or glass fibre, thermosetting matrix (Epoxy Resin) or thermoplastic matrix (Polyphenylene Sulfide). The specimens were submitted for 1800 hours to a hygrothermic test to evaluate moisture absorption on the basis of the Fick's law and finally tested to verify the mechanical properties (ultimate tensile strength). The results showed that the absorbed moisture decreases those properties of composites which were dominated by the matrix or the interface, while was not detectable the influence of water on the considered fibre. An important result is that the diffusion coefficient is highest for glass/PPS and lowest for carbon/epoxy composite material. The results give useful suggestions for the design of vehicle components that are exposed to environmental conditions (rain, snow and humidity).

  6. Identification of material properties of sandwich structure with piezoelectric patches

    Directory of Open Access Journals (Sweden)

    Zemčík R.

    2008-11-01

    Full Text Available The work focuses on light-weight sandwich structures made of carbon-epoxy skins and foam core which have unique bending stiffness compared to conventional materials. The skins are manufactured by vacuum autoclave technology from unidirectional prepregs and the sandwich is then glued together. The resulting material properties of the structure usually differ from those provided by manufacturer or even those obtained from experimental tests on separate materials, which makes computational models unreliable. Therefore, the properties are identified using the combination of experimental analysis of the sandwich with attached piezoelectric transducer and corresponding static and modal finite element analyses. Simple mathematical optimization with repetitive finite element solution is used. The model is then verified by transient analysis when the piezoelectric patch is excited by harmonic signals covering the first two eigen-frequencies and the induced oscillations are measured by laser sensor.

  7. Microwave Technologies-- Determination of Magnetic and Dielectric Materials Microwave Properties

    CERN Document Server

    Obol, Mahmut

    2009-01-01

    In this study, four different techniques are presented. 1 Rectangular waveguide measurement technique for normal microwave materials microwave properties such as permeability and permittivity. This technique removed guess parameter and dispersive effect issues of the old waveguide measurement techniques. It projects a new route for determination of any microwave materials magnetic and dielectric properties without using any guesses. 2 Coaxial probe measurement technique for the liquid and biological tissues dielectric permittivity. This coaxial probe technique has an advantage which is to attain the highest reflected signal from the coaxial probe tip, so that it is a fast and very sensitive technique to differentiate lossy materials dielectric permittivity. This technique could be useful non destructive detections for tumors in hospital and non destructive detections for chemical liquids as well. 3 A microstripline measurement technique for oxides microwave measurement at low frequency spectra where the waveg...

  8. Structure-property relationships in silica-siloxane nanocomposite materials

    Energy Technology Data Exchange (ETDEWEB)

    Ulibarri, T.A.; Derzon, D.K.; Wang, L.C.

    1997-03-01

    The simultaneous formation of a filler phase and a polymer matrix via in situ sol-gel techniques provides silica-siloxane nanocomposite materials of high strength. This study concentrates on the effects of temperature and relative humidity on a trimodal polymer system in an attempt to accelerate the reaction as well as evaluate subtle process- structure-property relations. It was found that successful process acceleration is only viable for high humidity systems when using the tin(IV) catalyst dibutyltin dilaurate. Processes involving low humidity were found to be very temperature and time dependent. Bimodal systems were investigated and demonstrated that the presence of a short-chain component led to enhanced material strength. This part of the study also revealed a link between the particle size and population density and the optimization of material properties.

  9. Evaluation of radiation-shielding properties of the composite material

    International Nuclear Information System (INIS)

    The paper presents the evaluation of radiation-shielding properties of composite materials with respect to gamma-radiation. As a binder for the synthesis of radiation-shielding composites we used lead boronsilicate glass matrix. As filler we used nanotubular chrysotile filled with lead tungstate PbWO4. It is shown that all the developed composites have good physical-mechanical characteristics, such as compressive strength, thermal stability and can be used as structural materials. On the basis of theoretical calculation we described the graphs of the gamma-quanta linear attenuation coefficient depending on the emitted energy for all investigated composites. We founded high radiation-shielding properties of all the composites on the basis of theoretical and experimental data compared to materials conventionally used in the nuclear industry - iron, concrete, etc

  10. Study of Radiation Induced Radicals in HAP and β-TCP Based Bone Graft Materials by ERP Spectroscopy

    International Nuclear Information System (INIS)

    Calcium phosphates such as beta-tricalcium phosphate (β-TCP) and hydroxyapatite (HAP) are frequently used as dental implants due to proven excellent biocompatibility. Because of their resorption in the body and direct contact with tissues, in order to inactivate bacteria, fungal spores and viruses, they are usually sterilized by γ-irradiation. However, literature provides little information about effects of γ-irradiation on the formation and stability of the free radicals in the bone graft materials during and after sterilization procedure. In this study EPR (electron paramagnetic resonance) spectroscopy was used to investigate HAP and β-TCP based dental implants present on the market. Eight dental graft materials present on the market were investigated: BioresorbR Macropore, PoresorbR-TCP, Easy-GraftTM and CerasorbR synthetic β-tricalcium phosphates, Easy-GraftTM crystal and OssceramR two phase synthetic CaP consisting of 60 % HAP and 40 % β-TCP, and DexaboneR and Bio-OssR bone graft material of bovine origin. EPR study shows that this is the only technique for characterization of free radicals that can simultaneously determine not only the presence and content, but also the position and the structure of free radicals formed by γ-sterilization in the investigated materials, as well as the paramagnetic substitutions incorporated in the materials during the synthesis (such as Mn2+, Fe3+ or Cr2+). Additionally, EPR provides information on stability of irradiation-induced radicals (CO2- , trapped H-atoms, NO32 etc.) and processes for reducing them. Results show that EPR should be considered as a valuable technique in improving the quality of bone graft materials, which must be sterile, and to offer the high quality, efficacy and reliable materials to the patients.(author)

  11. High Temperature Thermoelectric Properties of ZnO Based Materials

    DEFF Research Database (Denmark)

    Han, Li

    This thesis investigated the high temperature thermoelectric properties of ZnO based materials. The investigation first focused on the doping mechanisms of Al-doped ZnO, and then the influence of spark plasma sintering conditions on the thermoelectric properties of Al, Ga-dually doped ZnO. Follow......This thesis investigated the high temperature thermoelectric properties of ZnO based materials. The investigation first focused on the doping mechanisms of Al-doped ZnO, and then the influence of spark plasma sintering conditions on the thermoelectric properties of Al, Ga-dually doped Zn...... temperatures. Clear correlations between the initial crystallographic phase of the dopants and the thermoelectric properties of the resulting Al-doped ZnO were observed. For Al, Ga-dually doped ZnO, the spark plasma sintering conditions together with the microstructural evolution and thermoelectric properties...... of the samples were investigated in detail. A proposed solid-state-reaction model suggested that a sintering temperature above 1223K would be preferable in order to achieve phase equilibrium in the samples. The sintering mechanism of the ZnO particles and microstructural evolutions at different...

  12. Material Properties Analysis of Structural Members in Pumpkin Balloons

    Science.gov (United States)

    Sterling, W. J.

    2003-01-01

    The efficient design, service-life qualification, and reliability predictions for lightweight aerospace structures require careful mechanical properties analysis of candidate structural materials. The demand for high-quality laboratory data is particularly acute when the candidate material or the structural design has little history. The pumpkin-shaped super-pressure balloon presents both challenges. Its design utilizes load members (tendons) extending from apex to base around the gas envelope to achieve a lightweight structure. The candidate tendon material is highly weight-efficient braided HM cord. Previous mechanical properties studies of Zylon have focused on fiber and yarn, and industrial use of the material in tensile applications is limited. For high-performance polymers, a carefully plamed and executed properties analysis scheme is required to ensure the data are relevant to the desired application. Because no directly-applicable testing standard was available, a protocol was developed based on guidelines fiom professional and industry organizations. Due to the liquid-crystalline nature of the polymer, the cord is very stiff, creeps very little, and does not yield. Therefore, the key material property for this application is the breaking strength. The pretension load and gauge length were found to have negligible effect on the measured breaking strength over the ranges investigated. Strain rate was found to have no effect on breaking strength, within the range of rates suggested by the standards organizations. However, at the lower rate more similar to ULDB operations, the strength was reduced. The breaking strength increased when the experiment temperature was decreased from ambient to 183K which is the lowest temperature ULDB is expected to experience. The measured strength under all test conditions was well below that resulting from direct scale-up of fiber strength based on the manufacturers data. This expected result is due to the effects of the

  13. Resorbable glass-ceramic phosphate-based scaffolds for bone tissue engineering: synthesis, properties, and in vitro effects on human marrow stromal cells.

    Science.gov (United States)

    Vitale-Brovarone, Chiara; Ciapetti, Gabriela; Leonardi, Elisa; Baldini, Nicola; Bretcanu, Oana; Verné, Enrica; Baino, Francesco

    2011-11-01

    Highly porous bioresorbable glass-ceramic scaffolds were prepared via sponge replication method by using an open-cell polyurethane foam as a template and phosphate-based glass powders. The glass, belonging to the P2O5-SiO2-CaO-MgO-Na2O-K2O system, was synthesized by a melting-quenching route, ground, and sieved to obtain powders with a grain size of less than 30 μm. A slurry containing glass powders, polyvinyl alcohol, and water was prepared to coat the polymeric template. The removal of the polymer and the sintering of the glass powders were performed by a thermal treatment, in order to obtain an inorganic replica of the template structure. The structure and properties of the scaffold were investigated from structural, morphological, and mechanical viewpoints by means of X-ray diffraction, scanning electron microscopy, density measurements, image analysis, and compressive tests. The scaffolds exhibited a trabecular architecture that closely mimics the structure of a natural spongy bone. The solubility of the porous structures was assessed by soaking the samples in acellular simulated body fluid (SBF) and Tris-HCl for different time frames and then by assessing the scaffold weight loss. As far as the test in SBF is concerned, the nucleation of hydroxyapatite on the scaffold trabeculae demonstrates the bioactivity of the material. Biological tests were carried out using human bone marrow stromal cells to test the osteoconductivity of the material. The cells adhered to the scaffold struts and were metabolically active; it was found that cell differentiation over proliferation occurred. Therefore, the produced scaffolds, being biocompatible, bioactive, resorbable, and structurally similar to a spongy bone, can be proposed as interesting candidates for bone grafting. PMID:20566654

  14. Distribution and property of nerve fibers in human long bone tissue

    Institute of Scientific and Technical Information of China (English)

    CHEN Bin; PEI Guo-xian; JIN Dan; WEI Kuan-hai; QIN Yu; LIU Qing-si

    2007-01-01

    Objective:To observe the distribution of the nerve fibers in the bone tissue and the entry points of these fibers into the bone. Methods:The adult tibia was used for the ground sections which were afterwards made into the slice sections by decalcification in ethylenediamine tetraacetic acid (EDTA).The ground sections were stained in silver and the slice sections were stained in silver and haematoxylin and eosin (HE) respectively.Then,the samples of the transmission electron microscope and the atomic force microscope were made and observed. Results:In the human long bone tissue,many nerve fibers were distributed in the membrane,cortical bone,cancellous bone and marrow.The nerve fibers entered the bone from the nutrient foramen,and passed through the nutrient canal,Haversian's canal and Volkmann's canal,and finally into the bone marrow.In the nutrient canal,the nerve fibers,mainly the medullary nerve fibers,followed the blood vessel into the bone.In the cortical bone,the nerve fibers also followed the blood vessels and were mainly distributed along Haversian's canal and Volkmann's canal.In the bone trabecular and bone marrow,there were many nerve fiber endings arranged around the blood vessels,mainly around the tunica media of medium-size arteries in the marrow and around capillary blood vessels,and a few scattered in the bone marrow. There were sporadic nerve endings in epiphyseal plate and no nerve fibers permeated epiphysis to diaphysis.No distribution of nerve fibers could be found in cartilaginous part.Conclusions:There are many nerve fibers in bone and the nerve passageway is nutrient foramen,Volkman's canal,Haversian's canal and bone marrow.

  15. Characterization of the electromechanical properties of EAP materials

    Science.gov (United States)

    Bar-Cohen, Yoseph; Sherrita, Stewart; Bhattachary, Kaushik; Lih, Shyh-Shiuh

    2001-01-01

    Electroactive polymers (EAP) are an emerging class of actuation materials. Their large electrically induced strains (longitudinal or bending), low density, mechanical flexibility, and ease of processing offer advantages over traditional electroactive materials. However, before the capability of these materials can be exploited, their electrical and mechanical behavior must be properly quantified. Two general types of EAP can be identified. The first type is ionic EAP, which requires relatively low voltages (materials requires large electric fields (>100MV/m) to achieve longitudinal deformations at the range from 4 - 360%. Some of the difficulties in characterizing EAP include: nonlinear properties, large compliance (large mismatch with metal electrodes), nonhomogeneity resulting from processing, etc. To support the need for reliable data, the authors are developing characterization techniques to quantify the electroactive responses and material properties of EAP materials. The emphasis of the current study is on addressing electromechanical issues related to the ion-exchange type EAP also known as IPMC. The analysis, experiments and test results are discussed in this paper.

  16. Probabilistic model of human cortical bones with uncertain mechanical properties: Modelling and identification with experimental measurements in ultrasonic range

    OpenAIRE

    Desceliers, Christophe; Soize, Christian; Naili, S.; Grimal, Q.; Talmant, M.

    2010-01-01

    The biomechanical materials are among the most complex mechanical systems. Most often, their micro-structure are complex and random. This is the case for the human cortical bones which are considered in this paper. For such a system, the microstructure can be altered near its interface with the marrow (osteoporosis). A gradient of porosity is then observed in the thickness direction but, in this case, none usual theory of porous materials can be applied. For this reason, we present a simplifi...

  17. Microstructure characterization and magnetic properties of nano structured materials

    Energy Technology Data Exchange (ETDEWEB)

    Sun, X.C

    2000-07-01

    The present thesis deals with the unique microstructural properties and their novel magnetic properties of core-shell Ni-Ce nano composite particles, carbon encapsulated Fe, Co, and Ni nanoparticles and the nano crystallization behavior of typical ferromagnetic Fe{sub 78}Si{sub 9}B{sub 13} ribbons. These properties have intensively been investigated by high resolution transmission electron microscopy (HREM), X-ray diffraction (XRD), scanning electron microscopy (Sem), X-ray energy dispersive spectroscopy [eds.]; selected area electron diffraction pattern (SAED), Ft-IR, differential scanning calorimeter (DSC). In addition, magnetic moments measurements at different temperatures and applied fields have been performed by transmission Moessbauer spectroscopy, superconducting quantum interference device magnetometer (SQUID), and vibrating sample magnetometer (VSM). The present studies may provide the insights for the better understanding of the correlation between the unique microstructure and novel magnetic properties for several magnetic nano structured materials. (Author)

  18. Microstructure characterization and magnetic properties of nano structured materials

    International Nuclear Information System (INIS)

    The present thesis deals with the unique microstructural properties and their novel magnetic properties of core-shell Ni-Ce nano composite particles, carbon encapsulated Fe, Co, and Ni nanoparticles and the nano crystallization behavior of typical ferromagnetic Fe78Si9B13 ribbons. These properties have intensively been investigated by high resolution transmission electron microscopy (HREM), X-ray diffraction (XRD), scanning electron microscopy (Sem), X-ray energy dispersive spectroscopy (Eds.); selected area electron diffraction pattern (SAED), Ft-IR, differential scanning calorimeter (DSC). In addition, magnetic moments measurements at different temperatures and applied fields have been performed by transmission Moessbauer spectroscopy, superconducting quantum interference device magnetometer (SQUID), and vibrating sample magnetometer (VSM). The present studies may provide the insights for the better understanding of the correlation between the unique microstructure and novel magnetic properties for several magnetic nano structured materials. (Author)

  19. AB INITIO SIMULATIONS FOR MATERIAL PROPERTIES ALONG THE JUPITER ADIABAT

    International Nuclear Information System (INIS)

    We determine basic thermodynamic and transport properties of hydrogen-helium-water mixtures for the extreme conditions along Jupiter's adiabat via ab initio simulations, which are compiled in an accurate and consistent data set. In particular, we calculate the electrical and thermal conductivity, the shear and longitudinal viscosity, and diffusion coefficients of the nuclei. We present results for associated quantities like the magnetic and thermal diffusivity and the kinematic shear viscosity along an adiabat that is taken from a state-of-the-art interior structure model. Furthermore, the heat capacities, the thermal expansion coefficient, the isothermal compressibility, the Grüneisen parameter, and the speed of sound are calculated. We find that the onset of dissociation and ionization of hydrogen at about 0.9 Jupiter radii marks a region where the material properties change drastically. In the deep interior, where the electrons are degenerate, many of the material properties remain relatively constant. Our ab initio data will serve as a robust foundation for applications that require accurate knowledge of the material properties in Jupiter's interior, e.g., models for the dynamo generation.

  20. Properties of granular analogue model materials: A community wide survey

    Science.gov (United States)

    Klinkmüller, Matthias; Schreurs, Guido; Rosenau, Matthias; Kemnitz, Helga

    2016-04-01

    We report the material properties of 26 granular analogue materials used in 14 analogue modelling laboratories. We determined physical characteristics such as bulk density, grain size distribution, and grain shape, and performed ring shear tests to determine friction angles and cohesion, and uniaxial compression tests to evaluate the compaction behaviour. Mean grain size of the materials varied between (c. 100 and 400 micrometer). Analysis of grain shape factors show that the four different classes of granular materials (14 quartz sands, 5 dyed quartz sands, 4 heavy mineral sands and 3 size fractions of glass beads) can be broadly divided into two groups consisting of 12 angular and 14 rounded materials. Grain shape has an influence on friction angles, with most angular materials having higher internal friction angles (between c. 35° and 40°) than rounded materials, whereas well-rounded glass beads have the lowest internal friction angles (between c. 25° and 30°). We interpret this as an effect of intergranular sliding versus rolling . Most angular materials have also higher basal friction angles (tested for a specific foil) than more rounded materials, suggesting that angular grains scratch and wear the foil., Most materials have a cohesion in the order of 10-100 Pa except for well-rounded glass beads, which show a trend towards a quasi-cohesionless (C tests reveal that rounded grains generally show less compaction than angular grains. We interpret this to be related to the initial packing density reached during sieving which is higher for rounded grains than for angular grains. Ring-shear test data show that angular grains undergo a longer strain-hardening phase than more rounded materials. This might explain why analogue models consisting of angular grains accommodate deformation in a more distributed manner prior to strain localisation than models consisting of rounded grains. Also, models build with angular grains will tend to show more dilatancy during

  1. Organic/inorganic nanocomposite materials by electrospinning and their properties

    Science.gov (United States)

    Wang, Guan

    One-dimensional (1D) nanostructures, such as nanowires, nanobelts, nanofibers and nanotubes, have been the focus of intensive research due to their peculiar structures and resultant fascinating properties. However, the applications of 1D nanostructures have been hindered by the slow progress of the synthesis and characterization methods for these nanoscaled materials. Well controlled dimensionality, tailorable morphology and assembly, high phase purity and controllable crystallinity are major concerns when generating these nanostructures. In this work, a relatively simple technique---electrospinning---has been introduced for the preparation of 1D organic/inorganic nanocomposite materials. Materials under investigation include polymer/metal oxide (WO 3, MoO3) composite nanofibers and polymer/MWNT composite nanofibers. Notably, peculiar nanostructures, such as polycrystalline nanowires, nanoplatelets and nanobelts, can also be obtained after post-calcination processing on the nanocomposite materials. Spectroscopy techniques, such as XRD, SEM, TEM, AFM and Raman have been carried out to obtain structural and morphological information from the electrospun composite nanofibers. Meanwhile, some advanced characterization methods and measurements have been developed and designed to investigate the nanofibers from a basic science view point as to their properties. Specific designs of experiment include: synchrotron-based in situ XRD for phase transition monitoring; gas flow control bench for sensitivity measurement; three-point-bending by AFM for mechanical property measurement. In summary, the electrospinning technique provides a versatile method for synthesizing and assembling 1D nanocomposite structures. The electrospun composite nanofibers showed promising electrical and mechanical properties, which may find applications for gas sensors, reinforced fibrous materials and nano-electrical devices.

  2. Elastic therapeutic tape: do they have the same material properties?

    Science.gov (United States)

    Boonkerd, Chuanpis; Limroongreungrat, Weerawat

    2016-04-01

    [Purpose] Elastic therapeutic tape has been widely used for rehabilitation and treatment of sports injuries. Tapes with different elastic properties serve different treatment purposes with inappropriate tension reducing tape effectiveness. Many tapes are available in the market, but studies on tape properties are limited. The aim of this study was to examine the material properties of elastic therapeutic tape. [Subjects and Methods] Brands of elastic therapeutic tape included KinesioTex(®), ATex, Mueller, 3M, and ThaiTape. The Material Testing System Insight(®) 1 Electromechanical Testing Systems was used to apply a tensile force on elastic therapeutic tape. Ten specimens of each brand were tested. Stress, load, and Young's modulus at 25%, 50%, 75%, 100%, and maximum point were collected. One-way analysis of variance with post hoc testing was used to analyze tape parameters. [Results] Maximum elongation and Young's modulus at all percentages were significantly different between brands. There were no differences in maximum load and maximum stress. [Conclusion] Mechanical properties are different for commercial elastic therapeutic tapes. Physiotherapists and other clinicians should be aware of mechanical tape properties to correctly apply kinesio tape. PMID:27190472

  3. Elastic therapeutic tape: do they have the same material properties?

    Science.gov (United States)

    Boonkerd, Chuanpis; Limroongreungrat, Weerawat

    2016-01-01

    [Purpose] Elastic therapeutic tape has been widely used for rehabilitation and treatment of sports injuries. Tapes with different elastic properties serve different treatment purposes with inappropriate tension reducing tape effectiveness. Many tapes are available in the market, but studies on tape properties are limited. The aim of this study was to examine the material properties of elastic therapeutic tape. [Subjects and Methods] Brands of elastic therapeutic tape included KinesioTex®, ATex, Mueller, 3M, and ThaiTape. The Material Testing System Insight® 1 Electromechanical Testing Systems was used to apply a tensile force on elastic therapeutic tape. Ten specimens of each brand were tested. Stress, load, and Young’s modulus at 25%, 50%, 75%, 100%, and maximum point were collected. One-way analysis of variance with post hoc testing was used to analyze tape parameters. [Results] Maximum elongation and Young’s modulus at all percentages were significantly different between brands. There were no differences in maximum load and maximum stress. [Conclusion] Mechanical properties are different for commercial elastic therapeutic tapes. Physiotherapists and other clinicians should be aware of mechanical tape properties to correctly apply kinesio tape. PMID:27190472

  4. Production of a safer, osteogenic, tissue engineered bone allograft

    OpenAIRE

    Smith, Christopher Andrew

    2015-01-01

    The use of allograft bone is effective in the treatment of large bone loss following tumour removal or surgery. However, it is not osteogenic due to a lack of viable osteogenic cells and the remaining marrow material is potentially harmful to the recipient. Sterilisation techniques, such as gamma irradiation, are routinely used to improve the safety of these grafts; however this fails to remove the immunogenic material and may diminish the bones innate properties. Thus, wash techniques are be...

  5. Preparation and Properties of Orthogonal Piezoelectric Composite Materials

    Institute of Scientific and Technical Information of China (English)

    Liu Jun; Lu Ying; Zhang Xingguo; Shen Yi; Chen Chun

    2004-01-01

    . PZT piezoelectric ceramic with La2O3, SrCO3, BaO and Sb2O5 was prepared. It has high value of the piezoelectric strain constant d33 ( -681 PC/N) and high value of-d33/d31 (2.65). Orthogonal piezoelectric composite materials was designed and prepared by PZT, DAD- 40 electric conductive adhesive and E51 epoxy resin. The OPCM shows obvious orthogonal anisotropy. The matching property of the interface between piezoelectric ceramic and polymer of OPCM relies on the defects of interface. The proper conductive mid-layer could improve the matching property of the interface.

  6. Thermophysical properties of new materials; Proprietes thermophysiques des materiaux nouveaux

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    This conference day was organized by the `thermo-kinetics` section of the French association of thermal engineers. This book of proceedings contains 5 papers entitled: `characterization of thermal properties using periodical methods at the Odeillo test centre: developments and applications`; `measurement of the distribution of local thermophysical properties by IR images processing and averaging technique`; `extension of shock probes to the characterization of multi-layers - development of a simple device for the characterization of insulating materials or shear fluids`; `thermal local diffusivity of constituents of carbon/carbon composites`; `new method for the thermal diffusivity measurement of thermo-hardenable resins during polymerization`. (J.S.)

  7. Electrostatic levitation technology for thermophysical properties of molten materials

    Science.gov (United States)

    Rhim, Won-Kyu

    1993-01-01

    Measurements of thermophysical properties of undercooled liquids often require some kind of levitator which isolates samples from container walls. We introduce in this presentation a high temperature/high vacuum electrostatic levitator (HTHVESL) which promises some unique capabilities for the studies of thermophysical properties of molten materials. Although substantial progress has been made in the past several months, this technology is still in the development stage, therefore, in this presentation we only focus on the present state of the HTHVESL(1) and point out other capabilities which might be realized in the near future.

  8. Structure/property relationships in non-linear optical materials

    Energy Technology Data Exchange (ETDEWEB)

    Cole, J.M. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)]|[Durham Univ. (United Kingdom); Howard, J.A.K. [Durham Univ. (United Kingdom); McIntyre, G.J. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1997-04-01

    The application of neutrons to the study of structure/property relationships in organic non-linear optical materials (NLOs) is described. In particular, charge-transfer effects and intermolecular interactions are investigated. Charge-transfer effects are studied by charge-density analysis and an example of one such investigation is given. The study of intermolecular interactions concentrates on the effects of hydrogen-bonding and an example is given of two structurally similar molecules with very disparate NLO properties, as a result of different types of hydrogen-bonding. (author). 3 refs.

  9. Analysis of Mechanical Properties of Fabrics of Different Raw Material

    Directory of Open Access Journals (Sweden)

    Aušra ADOMAITIENĖ

    2011-07-01

    Full Text Available The study analyzes dependence of mechanical properties (breaking force, elongation at break, static friction force and static friction coefficient on integrated fabric structure factor j and raw material density r, among the fabrics of different raw material (cotton, wool, polypropylene, polyester and polyacrylnitrile and woven in different conditions. The received results demonstrate that sometimes strong dependences exist (wool, polypropylene and polyacrylnitrile, whereas in some cases (cotton and polyester there is no correlation. It was also discovered that the breaking force and elongation at break in the direction of weft increase, when fabric structure becomes more rigid. In the meantime variations of the curves in the direction of warp are insignificant. Regarding static friction force and static friction coefficient (found in two cases, when fabrics were rubbing against leather and materials, it was discovered that consistency of the curves is irregular, i. e. they either increase or decrease, when integrated fabric structure factor j growth. It was also identified that some dependences are not strong and relationship between explored and analyzed factors does not exist. Variation of all these mechanical properties with respect to material density r enables to conclude that increase of material density r results in poor dependences or they are whatsoever non-existent.http://dx.doi.org/10.5755/j01.ms.17.2.487

  10. Elastic and strength properties of metal rubber material

    Directory of Open Access Journals (Sweden)

    Alexander Aleksandrovich Troynikov

    2014-10-01

    Full Text Available MR material is a porous structure obtained by cold pressing of blanks from metal spiral into elastic elements finished by shape and size, which further will be formed into vibration isolators. The application efficiency of vibration isolators based on the MR material in the vibration isolation systems is mainly determined by its elastic and strength properties. This paper deals with experimental work, the relationship between technological and operational parameters is based on the similarity theory and dimensional analysis. The results of the study for practical use are obtained in closed form.

  11. Stiffness compatibility of coralline hydroxyapatite bone substitute under dynamic loading

    Institute of Scientific and Technical Information of China (English)

    REN ChaoFeng; HOU ZhenDe; ZHAO Wei

    2009-01-01

    When hydroxyapatite bone substitutes are implanted in human bodies, bone tissues will grow into their porous structure, which will reinforce their strength and stiffness. The concept of mechanical com-patibility of bone substitutes implies that their mechanical properties are similar to the bone tissues around, as if they were part of the bone. The mechanical compatibility of bone substitutes includes both static and dynamic behavior, due to the mechanical properties of bone depending on the strain rate. In this study, split Hopkinson pressure bar technique (SHPB) was employed to determine the dy-namic mechanical properties of coralline hydroxyapatite, bones with and bones without organic com-ponents, and their dynamic stress-strain curves of the three materials were obtained. The mechanical effects of collagens in bone were assessed, by comparing the difference between the Young's moduli of the three materials. As the implanted bone substitute becomes a part of bone, it can be regarded as an inclusion composite. The effective modulus of the composite was also evaluated in order to estimate its mechanical compatibility on stiffness. The evaluated result shows that the suitable porosity of HA is0.8, which is in favor of both static and dynamic stiffness compatibility.

  12. Stiffness compatibility of coralline hydroxyapatite bone substitute under dynamic loading

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    When hydroxyapatite bone substitutes are implanted in human bodies,bone tissues will grow into their porous structure,which will reinforce their strength and stiffness.The concept of mechanical com-patibility of bone substitutes implies that their mechanical properties are similar to the bone tissues around,as if they were part of the bone.The mechanical compatibility of bone substitutes includes both static and dynamic behavior,due to the mechanical properties of bone depending on the strain rate.In this study,split Hopkinson pressure bar technique(SHPB) was employed to determine the dy-namic mechanical properties of coralline hydroxyapatite,bones with and bones without organic com-ponents,and their dynamic stress-strain curves of the three materials were obtained.The mechanical effects of collagens in bone were assessed,by comparing the difference between the Young’s moduli of the three materials.As the implanted bone substitute becomes a part of bone,it can be regarded as an inclusion composite.The effective modulus of the composite was also evaluated in order to estimate its mechanical compatibility on stiffness.The evaluated result shows that the suitable porosity of HA is 0.8,which is in favor of both static and dynamic stiffness compatibility.

  13. Mechanical Properties of Materials with Nanometer Scale Microstructures

    Energy Technology Data Exchange (ETDEWEB)

    William D. Nix

    2004-10-31

    We have been engaged in research on the mechanical properties of materials with nanometer-scale microstructural dimensions. Our attention has been focused on studying the mechanical properties of thin films and interfaces and very small volumes of material. Because the dimensions of thin film samples are small (typically 1 mm in thickness, or less), specialized mechanical testing techniques based on nanoindentation, microbeam bending and dynamic vibration of micromachined structures have been developed and used. Here we report briefly on some of the results we have obtained over the past three years. We also give a summary of all of the dissertations, talks and publications completed on this grant during the past 15 years.

  14. Textile Materials with New Properties Used for Confections Manufacturing

    Directory of Open Access Journals (Sweden)

    Neacşu A. N.

    2009-12-01

    Full Text Available The quality of textile clothing depends on the quality of prime materials and also on the technology used; this must ensure a balance between transferred heat, resulted humidity and human and environmental thermal demands, all this bringing about physiological comfort. In order to meet consumers’ demands regarding the production of products which are easy to maintain and have high hygiene properties, new prime materials are searched, with a view to ensuring a wide range of clothing. Taking into consideration the acceleration of changes and the global inter-connections, a company must develop its capacity of innovation in order to bring products with new properties on the market before others do.

  15. Optical properties of glazing materials at normal incidence

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, M.; Powles, R.

    2001-10-01

    Measurements of spectral transmittance T and reflectance R at normal incidence continue to be the most common and accurate source of energy performance data for glazing materials. Prediction of these radiometric properties from more fundamental materials data is often confounded by the complexity and uncertainty of coating structures. Angle-dependent radiometric properties of coated glazing will probably be predicted from normal-incidence data rather than being measured at many angles. The general error level demonstrated in round-robin tests is on the order 1-2%; it is often necessary to achieve better levels of performance. Based on results obtained following the round-robin tests, it is expected that accuracy of better than 0.5% can be generally achieved. A new type of absolute standard reference is described and tested with promising results.

  16. Quantitative ultrasonic evaluation of mechanical properties of engineering materials

    Science.gov (United States)

    Vary, A.

    1978-01-01

    Current progress in the application of ultrasonic techniques to nondestructive measurement of mechanical strength properties of engineering materials is reviewed. Even where conventional NDE techniques have shown that a part is free of overt defects, advanced NDE techniques should be available to confirm the material properties assumed in the part's design. There are many instances where metallic, composite, or ceramic parts may be free of critical defects while still being susceptible to failure under design loads due to inadequate or degraded mechanical strength. This must be considered in any failure prevention scheme that relies on fracture analysis. This review will discuss the availability of ultrasonic methods that can be applied to actual parts to assess their potential susceptibility to failure under design conditions.

  17. Effective Materials Property Information Management for the 21st Century

    Science.gov (United States)

    Ren, Weiju; Cebon, David; Arnold, Steve

    2009-01-01

    This paper discusses key principles for the development of materials property information management software systems. There are growing needs for automated materials information management in various organizations. In part these are fueled by the demands for higher efficiency in material testing, product design and engineering analysis. But equally important, organizations are being driven by the need for consistency, quality and traceability of data, as well as control of access to sensitive information such as proprietary data. Further, the use of increasingly sophisticated nonlinear, anisotropic and multi-scale engineering analyses requires both processing of large volumes of test data for development of constitutive models and complex materials data input for Computer-Aided Engineering (CAE) software. And finally, the globalization of economy often generates great needs for sharing a single "gold source" of materials information between members of global engineering teams in extended supply chains. Fortunately, material property management systems have kept pace with the growing user demands and evolved to versatile data management systems that can be customized to specific user needs. The more sophisticated of these provide facilities for: (i) data management functions such as access, version, and quality controls; (ii) a wide range of data import, export and analysis capabilities; (iii) data "pedigree" traceability mechanisms; (iv) data searching, reporting and viewing tools; and (v) access to the information via a wide range of interfaces. In this paper the important requirements for advanced material data management systems, future challenges and opportunities such as automated error checking, data quality characterization, identification of gaps in datasets, as well as functionalities and business models to fuel database growth and maintenance are discussed.

  18. Assessment of the material properties of a fire damaged building

    OpenAIRE

    Oladipupo OLOMO; Olufikayo ADERINLEWO; Moses TANIMOLA; Silvana CROOPE

    2012-01-01

    This study identifies a process for assessing the material properties of a fire damaged building so as to determine whether the remains can be utilized in construction or be demolished. Physical and chemical analysis were carried out on concrete and steel samples taken from various elements of the building after thorough visual inspection of the entire building had been conducted. The physical (non-destructive) tests included the Schmidt hammer and ultrasonic pulse velocity tests on the concr...

  19. Tensile Properties of Fiber Materials under Different Strain Rates

    Institute of Scientific and Technical Information of China (English)

    XIONG Jie; GU Bo-hong; WANG Shan-yuan

    2002-01-01

    The quasi-static and dynamic tensile tests of aranid and high strength PVA fiber bundles are carried out under a wider range of strain rate by use of MTS (Materials Testing System) and bar-bar tensile impact apparatus.The influences of strain rate on mechanical properties of aramid and high strength polyvinyl alcohol fibers ar estudied. Micro failure mechanisms of fibers at different strain rates are examined by means of SEM.

  20. Modelling of electromagnetic material properties at microwave frequencies

    OpenAIRE

    Alsadi, Majid Hamid Nassar

    2012-01-01

    In recent years, electromagnetic interference (EMI) has raised serious issues in terms of the unintentional radiation that disrupts the near proximity equipment from working properly. One solution to reduce the effects of EMI is the use of electromagnetic shielding. Carbon fibre composite (CFC) material is a promising customised product that has entered numerous industrial areas due to its attractive properties like high strength, low weight, and the resistance to chemical substances and corr...