Mechanical analysis of non-uniform bi-directional functionally graded intelligent micro-beams using modified couple stress theory

NASA Astrophysics Data System (ADS)

Bakhshi Khaniki, Hossein; Rajasekaran, Sundaramoorthy

2018-05-01

This study develops a comprehensive investigation on mechanical behavior of non-uniform bi-directional functionally graded beam sensors in the framework of modified couple stress theory. Material variation is modelled through both length and thickness directions using power-law, sigmoid and exponential functions. Moreover, beam is assumed with linear, exponential and parabolic cross-section variation through the length using power-law and sigmoid varying functions. Using these assumptions, a general model for microbeams is presented and formulated by employing Hamilton’s principle. Governing equations are solved using a mixed finite element method with Lagrangian interpolation technique, Gaussian quadrature method and Wilson’s Lagrangian multiplier method. It is shown that by using bi-directional functionally graded materials in nonuniform microbeams, mechanical behavior of such structures could be affected noticeably and scale parameter has a significant effect in changing the rigidity of nonuniform bi-directional functionally graded beams.

Flexoelectric effect in functionally graded materials: A numerical study

NASA Astrophysics Data System (ADS)

Kumar, Anuruddh; Kiran, Raj; Kumar, Rajeev; Chandra Jain, Satish; Vaish, Rahul

2018-04-01

The flexoelectric effect has been observed in a wide range of dielectric materials. However, the flexoelectric effect can only be induced using the strain gradient. Researchers have examined the flexoelectricity using non-uniform loading (cantilever type) or non-uniform shape in dielectric materials, which may be undesirable in many applications. In the present article, we demonstrate induced flexoelectricity in dielectric functionally graded materials (FGMs) due to non-uniform Youngs's modulus along the thickness. To examine flexoelectricity, Ba0.6Sr0.4TiO3 (BST) and polyvinylidene fluoride (PVDF) were used to numerically simulate the performance of FGMs. 2D simulation suggests that output voltage can drastically enhance for optimum grading index of FGMs.

Methods of electrophoretic deposition for functionally graded porous nanostructures and systems thereof

DOEpatents

Worsley, Marcus A; Baumann, Theodore F; Satcher, Joe H; Olson, Tammy Y; Kuntz, Joshua D; Rose, Klint A

2015-03-03

In one embodiment, an aerogel includes a layer of shaped particles having a particle packing density gradient in a thickness direction of the layer, wherein the shaped particles are characterized by being formed in an electrophoretic deposition (EPD) process using an impurity. In another embodiment, a method for forming a functionally graded porous nanostructure includes adding particles of an impurity and a solution to an EPD chamber, applying a voltage difference across the two electrodes of the EPD chamber to create an electric field in the EPD chamber, and depositing the material onto surfaces of the particles of the impurity to form shaped particles of the material. Other functionally graded materials and methods are described according to more embodiments.

Thermo-Electro-Mechanical Analysis of a Curved Functionally Graded Piezoelectric Actuator with Sandwich Structure.

PubMed

Yan, Zhi; Zaman, Mostafa; Jiang, Liying

2011-12-12

In this work, the problem of a curved functionally graded piezoelectric (FGP) actuator with sandwich structure under electrical and thermal loads is investigated. The middle layer in the sandwich structure is functionally graded with the piezoelectric coefficient g 31 varying continuously along the radial direction of the curved actuator. Based on the theory of linear piezoelectricity, analytical solutions are obtained by using Airy stress function to examine the effects of material gradient and heat conduction on the performance of the curved actuator. It is found that the material gradient and thermal load have significant influence on the electroelastic fields and the mechanical response of the curved FGP actuator. Without the sacrifice of actuation deflection, smaller internal stresses are generated by using the sandwich actuator with functionally graded piezoelectric layer instead of the conventional bimorph actuator. This work is very helpful for the design and application of curved piezoelectric actuators under thermal environment.

Maximization of the Thermoelectric Cooling of a Graded Peltier Device by Analytical Heat-Equation Resolution

NASA Astrophysics Data System (ADS)

Thiébaut, E.; Goupil, C.; Pesty, F.; D'Angelo, Y.; Guegan, G.; Lecoeur, P.

2017-12-01

Increasing the maximum cooling effect of a Peltier cooler can be achieved through material and device design. The use of inhomogeneous, functionally graded materials may be adopted in order to increase maximum cooling without improvement of the Z T (figure of merit); however, these systems are usually based on the assumption that the local optimization of the Z T is the suitable criterion to increase thermoelectric performance. We solve the heat equation in a graded material and perform both analytical and numerical analysis of a graded Peltier cooler. We find a local criterion that we use to assess the possible improvement of graded materials for thermoelectric cooling. A fair improvement of the cooling effect (up to 36%) is predicted for semiconductor materials, and the best graded system for cooling is described. The influence of the equation of state of the electronic gas of the material is discussed, and the difference in term of entropy production between the graded and the classical system is also described.

Impact of interfacial imperfection on transverse wave in a functionally graded piezoelectric material structure with corrugated boundaries

NASA Astrophysics Data System (ADS)

Kumar Singh, Abhishek; Kumar, Santan; Kumari, Richa

2018-03-01

The propagation behavior of Love-type wave in a corrugated functionally graded piezoelectric material layered structure has been taken into account. Concretely, the layered structure incorporates a corrugated functionally graded piezoelectric material layer imperfectly bonded to a functionally graded piezoelectric material half-space. An analytical treatment has been employed to determine the dispersion relation for both cases of electrically open condition and electrically short condition. The phase velocity of the Love-type wave has been computed numerically and its dependence on the wave number has been depicted graphically for a specific type of corrugated boundary surfaces for both said conditions. The crux of the study lies in the fact that the imperfect bonding of the interface, the corrugated boundaries present in the layer, and the material properties of the layer and the half-space strongly influence the phase velocity of the Love-type wave. It can be remarkably noted that the imperfect bonding of the interface reduces the phase velocity of the Love-type wave significantly. As a special case of the problem, it is noticed that the procured dispersion relation for both cases of electrically open and electrically short conditions is in accordance with the classical Love wave equation.

An Exploration of Several Structural Measurement Techniques for Usage with Functionally Graded Materials

DTIC Science & Technology

2006-12-01

Welsch, and E.W. Collings, eds. Materials Properties Handbook: Titanium Alloys . ASM International: 1994. p. 179 Davis, Joseph, ed. Properties ...AN EXPLORATION OF SEVERAL STRUCTURAL MEASUREMENT TECHNIQUES FOR USAGE WITH FUNCTIONALLY GRADED...of Defense, or the United States Government. AFIT/GAE/ENY/07-D03 AN EXPLORATION OF SEVERAL STRUCTURAL MEASUREMENT TECHNIQUES FOR USAGE WITH

Finite element analysis of functionally graded bone plate at femur bone fracture site

NASA Astrophysics Data System (ADS)

Satapathy, Pravat Kumar; Sahoo, Bamadev; Panda, L. N.; Das, S.

2018-03-01

This paper focuses on the analysis of fractured Femur bone with functionally graded bone plate. The Femur bone is modeled by using the data from the CT (Computerized Tomography) scan and the material properties are assigned using Mimics software. The fracture fixation plate used here is composed of Functionally Graded Material (FGM). The functionally graded bone plate is considered to be composed of different layers of homogeneous materials. Finite element method approach is adopted for analysis. The volume fraction of the material is calculated by considering its variation along the thickness direction (z) according to a power law and the effective properties of the homogeneous layers are estimated. The model developed is validated by comparing numerical results available in the literature. Static analysis has been performed for the bone plate system by considering both axial compressive load and torsional load. The investigation shows that by introducing FG bone plate instead of titanium, the stress at the fracture site increases by 63 percentage and the deformation decreases by 15 percentage, especially when torsional load is taken into consideration. The present model yields better results in comparison with the commercially available bone plates.

Digital fabrication of multi-material biomedical objects.

PubMed

Cheung, H H; Choi, S H

2009-12-01

This paper describes a multi-material virtual prototyping (MMVP) system for modelling and digital fabrication of discrete and functionally graded multi-material objects for biomedical applications. The MMVP system consists of a DMMVP module, an FGMVP module and a virtual reality (VR) simulation module. The DMMVP module is used to model discrete multi-material (DMM) objects, while the FGMVP module is for functionally graded multi-material (FGM) objects. The VR simulation module integrates these two modules to perform digital fabrication of multi-material objects, which can be subsequently visualized and analysed in a virtual environment to optimize MMLM processes for fabrication of product prototypes. Using the MMVP system, two biomedical objects, including a DMM human spine and an FGM intervertebral disc spacer are modelled and digitally fabricated for visualization and analysis in a VR environment. These studies show that the MMVP system is a practical tool for modelling, visualization, and subsequent fabrication of biomedical objects of discrete and functionally graded multi-materials for biomedical applications. The system may be adapted to control MMLM machines with appropriate hardware for physical fabrication of biomedical objects.

Design, Manufacturing and Characterization of Functionally Graded Flextensional Piezoelectric Actuators

NASA Astrophysics Data System (ADS)

Amigo, R. C. R.; Vatanabe, S. L.; Silva, E. C. N.

2013-03-01

Previous works have been shown several advantages in using Functionally Graded Materials (FGMs) for the performance of flextensional devices, such as reduction of stress concentrations and gains in reliability. In this work, the FGM concept is explored in the design of graded devices by using the Topology Optimization Method (TOM), in order to determine optimal topologies and gradations of the coupled structures of piezoactuators. The graded pieces are manufactured by using the Spark Plasma Sintering (SPS) technique and are bonded to piezoelectric ceramics. The graded actuators are then tested by using a modular vibrometer system for measuring output displacements, in order to validate the numerical simulations. The technological path developed here represents the initial step toward the manufacturing of an integral piezoelectric device, constituted by piezoelectric and non-piezoelectric materials without bonding layers.

Thermo-Electro-Mechanical Analysis of a Curved Functionally Graded Piezoelectric Actuator with Sandwich Structure

PubMed Central

Yan, Zhi; Zaman, Mostafa; Jiang, Liying

2011-01-01

In this work, the problem of a curved functionally graded piezoelectric (FGP) actuator with sandwich structure under electrical and thermal loads is investigated. The middle layer in the sandwich structure is functionally graded with the piezoelectric coefficient g31 varying continuously along the radial direction of the curved actuator. Based on the theory of linear piezoelectricity, analytical solutions are obtained by using Airy stress function to examine the effects of material gradient and heat conduction on the performance of the curved actuator. It is found that the material gradient and thermal load have significant influence on the electroelastic fields and the mechanical response of the curved FGP actuator. Without the sacrifice of actuation deflection, smaller internal stresses are generated by using the sandwich actuator with functionally graded piezoelectric layer instead of the conventional bimorph actuator. This work is very helpful for the design and application of curved piezoelectric actuators under thermal environment. PMID:28824130

Micromechanics and Structural Response of Functionally Graded, Particulate-Matrix, Fiber-Reinforced Composites

PubMed Central

Genin, Guy M.; Birman, Victor

2009-01-01

Reinforcement of fibrous composites by stiff particles embedded in the matrix offers the potential for simple, economical functional grading, enhanced response to mechanical loads, and improved functioning at high temperatures. Here, we consider laminated plates made of such a material, with spherical reinforcement tailored by layer. The moduli for this material lie within relatively narrow bounds. Two separate moduli estimates are considered: a “two-step” approach in which fibers are embedded in a homogenized particulate matrix, and the Kanaun-Jeulin (2001) approach, which we re-derive in a simple way using the Benveniste (1988) method. Optimal tailoring of a plate is explored, and functional grading is shown to improve the performance of the structures considered. In the example of a square, simply supported, cross-ply laminated panel subjected to uniform transverse pressure, a modest functional grading offers significant improvement in performance. A second example suggests superior blast resistance of the panel achieved at the expense of only a small increase in weight. PMID:23874001

Nanoscale Graphene Disk: A Natural Functionally Graded Material-How is Fourier's Law Violated along Radius Direction of 2D Disk.

PubMed

Yang, Nuo; Hu, Shiqian; Ma, Dengke; Lu, Tingyu; Li, Baowen

2015-10-07

In this Paper, we investigate numerically and analytically the thermal conductivity of nanoscale graphene disks (NGDs), and discussed the possibility to realize functionally graded material (FGM) with only one material, NGDs. Different from previous studies on divergence/non-diffusive of thermal conductivity in nano-structures with different size, we found a novel non-homogeneous (graded) thermal conductivity along the radius direction in a single nano-disk structure. We found that, instead of a constant value, the NGD has a graded thermal conductivity along the radius direction. That is, Fourier's law of heat conduction is not valid in two dimensional graphene disk structures Moreover, we show the dependent of NGDs' thermal conductivity on radius and temperature. Our study might inspire experimentalists to develop NGD based versatile FGMs, improve understanding of the heat removal of hot spots on chips, and enhance thermoelectric energy conversion efficiency by two dimensional disk with a graded thermal conductivity.

Characterization of pore and crystal structure of synthesized LiBOB with varying quality of raw materials as electrolyte for lithium-ion battery

NASA Astrophysics Data System (ADS)

Lestariningsih, Titik; Ratri, Christin Rina; Wigayati, Etty Marty; Sabrina, Qolby

2016-02-01

Characterization of pore structure and crystal structure of the LiB(C2O4)2H2O or LIBOB compound has been performed in this study. These recent years, research regarding LiBOB electrolyte salt have been performed using analytical-grade raw materials, therefore this research was aimed to synthesized LiBOB electrolyte salt using the cheaper and abundant technical-grade raw materials. Lithium hydroxide (LiOH), oxalic acid dihydrate (H2C2O4.2H2O), and boric acid (H3BO3) both in technical-grade and analytical-grade quality were used as raw materials for the synthesis of LiBOB. Crystal structure characterization results of synthesized LiBOB from both technical-grade and analytical-grade raw materials have shown the existence of LiBOB and LiBOB hydrate phase with orthorombic structure. These results were also confirmed by FT-IR analysis, which showed the functional groups of LiBOB compounds. SEM analysis results showed that synthesized LiBOB has spherical structure, while commercial LiBOB has cylindrical structure. Synthesized LiBOB has a similar pore size of commercial LiBOB, i.e. 19 nm (mesoporous material). Surface area of synthesized LiBOB from analytical-grade raw materials and technical-grade materials as well as commercial LIBOB were 88.556 m2/g, 41.524 m2/g, and 108.776 m2/g, respectively. EIS analysis results showed that synthesized LiBOB from technical-grade raw materials has lower conductivity than synthesized LiBOB from analytical-grade raw materials.

Evaluation of Multi-Functional Materials for Deep Space Radiation Shielding

NASA Technical Reports Server (NTRS)

Rojdev, Kristina; Atwell, William; Wilkins, Richard; Gersey, Brad; Badavi, Francis F.

2009-01-01

Small scale trade study of materials for radiation shielding: a) High-hydrogen polymers; b) Z-graded materials; c) Fiber-reinforced polymer composites. Discussed multi-functionality of fiber-reinforced polymer composites. Preliminary results of ground testing data.

Rayleigh wave behavior in functionally graded magneto-electro-elastic material

NASA Astrophysics Data System (ADS)

Ezzin, Hamdi; Mkaoir, Mohamed; Amor, Morched Ben

2017-12-01

Piezoelectric-piezomagnetic functionally graded materials, with a gradual change of the mechanical and electromagnetic properties have greatly applying promises. Based on the ordinary differential equation and stiffness matrix methods, a dynamic solution is presented for the propagation of the wave on a semi-infinite piezomagnetic substrate covered with a functionally graded piezoelectric material (FGPM) layer. The materials properties are assumed to vary in the direction of the thickness according to a known variation law. The phase and group velocity of the Rayleigh wave is numerically calculated for the magneto-electrically open and short cases, respectively. The effect of gradient coefficients on the phase velocity, group velocity, coupled magneto-electromechanical factor, on the stress fields, the magnetic potential and the mechanical displacement are discussed, respectively. Illustration is achieved on the hetero-structure PZT-5A/CoFe2O4; the obtained results are especially useful in the design of high-performance acoustic surface devices and accurately prediction of the Rayleigh wave propagation behavior.

Dynamic response of porous functionally graded material nanobeams subjected to moving nanoparticle based on nonlocal strain gradient theory

NASA Astrophysics Data System (ADS)

Barati, Mohammad Reza

2017-11-01

Up to now, nonlocal strain gradient theory (NSGT) is broadly applied to examine free vibration, static bending and buckling of nanobeams. This theory captures nonlocal stress field effects together with the microstructure-dependent strain gradient effects. In this study, forced vibrations of NSGT nanobeams on elastic substrate subjected to moving loads are examined. The nanobeam is made of functionally graded material (FGM) with even and uneven porosity distributions inside the material structure. The graded material properties with porosities are described by a modified power-law model. Dynamic deflection of the nanobeam is obtained via Galerkin and inverse Laplace transform methods. The importance of nonlocal parameter, strain gradient parameter, moving load velocity, porosity volume fraction, type of porosity distribution and elastic foundation on forced vibration behavior of nanobeams are discussed.

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

PubMed

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

Method and apparatus for determination of mechanical properties of functionally-graded materials

DOEpatents

Giannakopoulos, Antonios E.; Suresh, Subra

1999-01-01

Techniques for the determination of mechanical properties of homogenous or functionally-graded materials from indentation testing are presented. The technique is applicable to indentation on the nano-scale through the macro-scale including the geological scale. The technique involves creating a predictive load/depth relationship for a sample, providing an experimental load/depth relationship, comparing the experimental data to the predictive data, and determining a physical characteristic from the comparison.

Functionally Graded Adhesives for Composite Joints

NASA Technical Reports Server (NTRS)

Stapleton, Scott E.; Waas, Anthony M.; Arnold, Steven M.

2012-01-01

Adhesives with functionally graded material properties are being considered for use in adhesively bonded joints to reduce the peel stress concentrations located near adherend discontinuities. Several practical concerns impede the actual use of such adhesives. These include increased manufacturing complications, alterations to the grading due to adhesive flow during manufacturing, and whether changing the loading conditions significantly impact the effectiveness of the grading. An analytical study is conducted to address these three concerns. An enhanced joint finite element, which uses an analytical formulation to obtain exact shape functions, is used to model the joint. Furthermore, proof of concept testing is conducted to show the potential advantages of functionally graded adhesives. In this study, grading is achieved by strategically placing glass beads within the adhesive layer at different densities along the joint.

Crack propagation in functionally graded strip under thermal shock

NASA Astrophysics Data System (ADS)

Ivanov, I. V.; Sadowski, T.; Pietras, D.

2013-09-01

The thermal shock problem in a strip made of functionally graded composite with an interpenetrating network micro-structure of Al2O3 and Al is analysed numerically. The material considered here could be used in brake disks or cylinder liners. In both applications it is subjected to thermal shock. The description of the position-dependent properties of the considered functionally graded material are based on experimental data. Continuous functions were constructed for the Young's modulus, thermal expansion coefficient, thermal conductivity and thermal diffusivity and implemented as user-defined material properties in user-defined subroutines of the commercial finite element software ABAQUS™. The thermal stress and the residual stress of the manufacturing process distributions inside the strip are considered. The solution of the transient heat conduction problem for thermal shock is used for crack propagation simulation using the XFEM method. The crack length developed during the thermal shock is the criterion for crack resistance of the different graduation profiles as a step towards optimization of the composition gradient with respect to thermal shock sensitivity.

Asphalt pavement aging and temperature dependent properties using functionally graded viscoelastic model

NASA Astrophysics Data System (ADS)

Dave, Eshan V.

Asphalt concrete pavements are inherently graded viscoelastic structures. Oxidative aging of asphalt binder and temperature cycling due to climatic conditions being the major cause of non-homogeneity. Current pavement analysis and simulation procedures dwell on the use of layered approach to account for these non-homogeneities. The conventional finite-element modeling (FEM) technique discretizes the problem domain into smaller elements, each with a unique constitutive property. However the assignment of unique material property description to an element in the FEM approach makes it an unattractive choice for simulation of problems with material non-homogeneities. Specialized elements such as "graded elements" allow for non-homogenous material property definitions within an element. This dissertation describes the development of graded viscoelastic finite element analysis method and its application for analysis of asphalt concrete pavements. Results show that the present research improves efficiency and accuracy of simulations for asphalt pavement systems. Some of the practical implications of this work include the new technique's capability for accurate analysis and design of asphalt pavements and overlay systems and for the determination of pavement performance with varying climatic conditions and amount of in-service age. Other application areas include simulation of functionally graded fiber-reinforced concrete, geotechnical materials, metal and metal composites at high temperatures, polymers, and several other naturally existing and engineered materials.

Longitudinal Fracture Analysis of a Two-Dimensional Functionally Graded Beam

NASA Astrophysics Data System (ADS)

Rizov, V.

2017-11-01

Longitudinal fracture in a two-dimensional functionally graded beam is analyzed. The modulus of elasticity varies continuously in the beam cross-section. The beam is clamped in its right-hand end. The external loading consists of one longitudinal force applied at the free end of the lower crack arm. The longitudinal crack is located in the beam mid-plane. The fracture is studied in terms of the strain energy release rate. The solution derived is used to elucidate the effects of material gradients along the height as well as along the width of the beam cross-section on the fracture behaviour. The results obtained indicate that the fracture in two-dimensional functionally graded beams can be regulated efficiently by employing appropriate material gradients.

Bioinspired design of dental multilayers.

PubMed

Huang, M; Wang, R; Thompson, V; Rekow, D; Soboyejo, W O

2007-01-01

This paper considers the use of bioinspired functionally graded structures in the design of dental multi-layers that are more resistant to sub-surface crack nucleation. Unlike existing dental crown restorations that give rise to high stress concentration, the functionally graded layers (between crown materials and the joins that attach them to dentin) are shown to promote significant reductions in stress and improvements in the critical crack size. Special inspiration is drawn from the low stress concentrations associated with the graded distributions in the dentin-enamel-junction (DEJ). The implications of such functionally graded structures are also discussed for the design of dental restorations.

Analytical solution for wave propagation through a graded index interface between a right-handed and a left-handed material.

PubMed

Dalarsson, Mariana; Tassin, Philippe

2009-04-13

We have investigated the transmission and reflection properties of structures incorporating left-handed materials with graded index of refraction. We present an exact analytical solution to Helmholtz' equation for a graded index profile changing according to a hyperbolic tangent function along the propagation direction. We derive expressions for the field intensity along the graded index structure, and we show excellent agreement between the analytical solution and the corresponding results obtained by accurate numerical simulations. Our model straightforwardly allows for arbitrary spectral dispersion.

Generalized Constitutive-Based Theoretical and Empirical Models for Hot Working Behavior of Functionally Graded Steels

NASA Astrophysics Data System (ADS)

Vanini, Seyed Ali Sadough; Abolghasemzadeh, Mohammad; Assadi, Abbas

2013-07-01

Functionally graded steels with graded ferritic and austenitic regions including bainite and martensite intermediate layers produced by electroslag remelting have attracted much attention in recent years. In this article, an empirical model based on the Zener-Hollomon (Z-H) constitutive equation with generalized material constants is presented to investigate the effects of temperature and strain rate on the hot working behavior of functionally graded steels. Next, a theoretical model, generalized by strain compensation, is developed for the flow stress estimation of functionally graded steels under hot compression based on the phase mixture rule and boundary layer characteristics. The model is used for different strains and grading configurations. Specifically, the results for αβγMγ steels from empirical and theoretical models showed excellent agreement with those of experiments of other references within acceptable error.

Enhanced protective role in materials with gradient structural orientations: Lessons from Nature.

PubMed

Liu, Zengqian; Zhu, Yankun; Jiao, Da; Weng, Zhaoyong; Zhang, Zhefeng; Ritchie, Robert O

2016-10-15

Living organisms are adept at resisting contact deformation and damage by assembling protective surfaces with spatially varied mechanical properties, i.e., by creating functionally graded materials. Such gradients, together with multiple length-scale hierarchical structures, represent the two prime characteristics of many biological materials to be translated into engineering design. Here, we examine one design motif from a variety of biological tissues and materials where site-specific mechanical properties are generated for enhanced protection by adopting gradients in structural orientation over multiple length-scales, without manipulation of composition or microstructural dimension. Quantitative correlations are established between the structural orientations and local mechanical properties, such as stiffness, strength and fracture resistance; based on such gradients, the underlying mechanisms for the enhanced protective role of these materials are clarified. Theoretical analysis is presented and corroborated through numerical simulations of the indentation behavior of composites with distinct orientations. The design strategy of such bioinspired gradients is outlined in terms of the geometry of constituents. This study may offer a feasible approach towards generating functionally graded mechanical properties in synthetic materials for improved contact damage resistance. Living organisms are adept at resisting contact damage by assembling protective surfaces with spatially varied mechanical properties, i.e., by creating functionally-graded materials. Such gradients, together with multiple length-scale hierarchical structures, represent the prime characteristics of many biological materials. Here, we examine one design motif from a variety of biological tissues where site-specific mechanical properties are generated for enhanced protection by adopting gradients in structural orientation at multiple length-scales, without changes in composition or microstructural dimension. The design strategy of such bioinspired gradients is outlined in terms of the geometry of constituents. This study may offer a feasible approach towards generating functionally-graded mechanical properties in synthetic materials for improved damage resistance. Published by Elsevier Ltd.

Vibration analysis and transient response of a functionally graded piezoelectric curved beam with general boundary conditions

NASA Astrophysics Data System (ADS)

Su, Zhu; Jin, Guoyong; Ye, Tiangui

2016-06-01

The paper presents a unified solution for free and transient vibration analyses of a functionally graded piezoelectric curved beam with general boundary conditions within the framework of Timoshenko beam theory. The formulation is derived by means of the variational principle in conjunction with a modified Fourier series which consists of standard Fourier cosine series and supplemented functions. The mechanical and electrical properties of functionally graded piezoelectric materials (FGPMs) are assumed to vary continuously in the thickness direction and are estimated by Voigt’s rule of mixture. The convergence, accuracy and reliability of the present formulation are demonstrated by comparing the present solutions with those from the literature and finite element analysis. Numerous results for FGPM beams with different boundary conditions, geometrical parameters as well as material distributions are given. Moreover, forced vibration of the FGPM beams subjected to dynamic loads and general boundary conditions are also investigated.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dr. Mohit Jain; Dr. Ganesh Skandan; Dr. Gordon E. Khose

Generation IV Very High Temperature power generating nuclear reactors will operate at temperatures greater than 900 oC. At these temperatures, the components operating in these reactors need to be fabricated from materials with excellent thermo-mechanical properties. Conventional pure or composite materials have fallen short in delivering the desired performance. New materials, or conventional materials with new microstructures, and associated processing technologies are needed to meet these materials challenges. Using the concept of functionally graded materials, we have fabricated a composite material which has taken advantages of the mechanical and thermal properties of ceramic and metals. Functionally-graded composite samples with variousmore » microstructures were fabricated. It was demonstrated that the composition and spatial variation in the composition of the composite can be controlled. Some of the samples were tested for irradiation resistance to neutrons. The samples did not degrade during initial neutron irradiation testing.« less

Recent development in modeling and analysis of functionally graded materials and structures

NASA Astrophysics Data System (ADS)

Gupta, Ankit; Talha, Mohammad

2015-11-01

In this article, an extensive review related to the structural response of the functionally graded materials (FGMs) and structures have been presented. These are high technology materials developed by a group scientist in the late 1980's in Japan. The emphasis has been made here, to present the structural characteristics of FGMs plates/shells under thermo-electro-mechanical loadings under various boundary and environmental conditions. This paper also provides an overview of different fabrication procedures and the future research directions which is required to implement these materials in the design and analysis appropriately. The expected outcome of present review can be treated as milestone for future studies in the area of high technology materials and structures, and would be definitely advantageous for the researchers, scientists, and designers working in this field.

Dynamic Response of Layered TiB/Ti Functionally Graded Material Specimens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Byrd, Larry; Beberniss, Tim; Chapman, Ben

2008-02-15

This paper covers the dynamic response of rectangular (25.4x101.6x3.175 mm) specimens manufactured from layers of TiB/Ti. The layers contained volume fractions of TiB that varied from 0 to 85% and thus formed a functionally graded material. Witness samples of the 85% TiB material were also tested to provide a baseline for the statistical variability of the test techniques. Static and dynamic tests were performed to determine the in situ material properties and fundamental frequencies. Damping in the material/ fixture was also found from the dynamic response. These tests were simulated using composite beam theory which gave an analytical solution, andmore » using finite element analysis. The response of the 85% TiB specimens was found to be much more uniform than the functionally graded material and the dynamic response more uniform than the static response. A least squares analysis of the data using the analytical solutions were used to determine the elastic modulus and Poisson's ratio of each layer. These results were used to model the response in the finite element analysis. The results indicate that current analytical and numerical methods for modeling the material give similar and adequate predictions for natural frequencies if the measured property values were used. The models did not agree as well if the properties from the manufacturer or those of Hill and Linn were used.« less

Design of phononic band gaps in functionally graded piezocomposite materials by using topology optimization

NASA Astrophysics Data System (ADS)

Vatanabe, Sandro L.; Silva, Emílio C. N.

2011-04-01

One of the properties of composite materials is the possibility of having phononic band gaps, within which sound and vibrations at certain frequencies do not propagate. These materials are called Phononic Crystals (PCs). PCs with large band gaps are of great interest for many applications, such as transducers, elastic/ acoustic filters, noise control, and vibration shields. Most of previous works concentrates on PCs made of elastic isotropic materials; however, band gaps can be enlarged by using non-isotropic materials, such as piezoelectric materials. Since the main property of PCs is the presence of band gaps, one possible way to design structures which have a desired band gap is through Topology Optimization Method (TOM). TOM is a computational technique that determines the layout of a material such that a prescribed objective is maximized. Functionally Graded Materials (FGM) are composite materials whose properties vary gradually and continuously along a specific direction within the domain of the material. One of the advantages of applying the FGM concept to TOM is that it is not necessary a discrete 0-1 result, once the material gradation is part of the solution. Therefore, the interpretation step becomes easier and the dispersion diagram obtained from the optimization is not significantly modified. In this work, the main objective is to optimize the position and width of piezocomposite materials band gaps. Finite element analysis is implemented with Bloch-Floquet theory to solve the dynamic behavior of two-dimensional functionally graded unit cells. The results demonstrate that phononic band gaps can be designed by using this methodology.

Nanoscale Graphene Disk: A Natural Functionally Graded Material–How is Fourier’s Law Violated along Radius Direction of 2D Disk

PubMed Central

Yang, Nuo; Hu, Shiqian; Ma, Dengke; Lu, Tingyu; Li, Baowen

2015-01-01

In this Paper, we investigate numerically and analytically the thermal conductivity of nanoscale graphene disks (NGDs), and discussed the possibility to realize functionally graded material (FGM) with only one material, NGDs. Different from previous studies on divergence/non-diffusive of thermal conductivity in nano-structures with different size, we found a novel non-homogeneous (graded) thermal conductivity along the radius direction in a single nano-disk structure. We found that, instead of a constant value, the NGD has a graded thermal conductivity along the radius direction. That is, Fourier’s law of heat conduction is not valid in two dimensional graphene disk structures Moreover, we show the dependent of NGDs’ thermal conductivity on radius and temperature. Our study might inspire experimentalists to develop NGD based versatile FGMs, improve understanding of the heat removal of hot spots on chips, and enhance thermoelectric energy conversion efficiency by two dimensional disk with a graded thermal conductivity. PMID:26443206

Ceramic-Based 4D Components: Additive Manufacturing (AM) of Ceramic-Based Functionally Graded Materials (FGM) by Thermoplastic 3D Printing (T3DP).

PubMed

Scheithauer, Uwe; Weingarten, Steven; Johne, Robert; Schwarzer, Eric; Abel, Johannes; Richter, Hans-Jürgen; Moritz, Tassilo; Michaelis, Alexander

2017-11-28

In our study, we investigated the additive manufacturing (AM) of ceramic-based functionally graded materials (FGM) by the direct AM technology thermoplastic 3D printing (T3DP). Zirconia components with varying microstructures were additively manufactured by using thermoplastic suspensions with different contents of pore-forming agents (PFA), which were co-sintered defect-free. Different materials were investigated concerning their suitability as PFA for the T3DP process. Diverse zirconia-based suspensions were prepared and used for the AM of single- and multi-material test components. All of the samples were sintered defect-free, and in the end, we could realize a brick wall-like component consisting of dense (<1% porosity) and porous (approx. 5% porosity) zirconia areas to combine different properties in one component. T3DP opens the door to the AM of further ceramic-based 4D components, such as multi-color, multi-material, or especially, multi-functional components.

Ceramic-Based 4D Components: Additive Manufacturing (AM) of Ceramic-Based Functionally Graded Materials (FGM) by Thermoplastic 3D Printing (T3DP)

PubMed Central

Weingarten, Steven; Johne, Robert; Schwarzer, Eric; Richter, Hans-Jürgen; Michaelis, Alexander

2017-01-01

In our study, we investigated the additive manufacturing (AM) of ceramic-based functionally graded materials (FGM) by the direct AM technology thermoplastic 3D printing (T3DP). Zirconia components with varying microstructures were additively manufactured by using thermoplastic suspensions with different contents of pore-forming agents (PFA), which were co-sintered defect-free. Different materials were investigated concerning their suitability as PFA for the T3DP process. Diverse zirconia-based suspensions were prepared and used for the AM of single- and multi-material test components. All of the samples were sintered defect-free, and in the end, we could realize a brick wall-like component consisting of dense (<1% porosity) and porous (approx. 5% porosity) zirconia areas to combine different properties in one component. T3DP opens the door to the AM of further ceramic-based 4D components, such as multi-color, multi-material, or especially, multi-functional components. PMID:29182541

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoynov, Y.

Functionally graded materials (FGM) are extensively used in modern industry. They are composite materials with continuously varying properties in one or more special dimensions, according to the specific purpose. In view of the wide range of applications of FGM, stress analysis is important for their structural integrity and reliable service life. In this study we will consider functionally graded magneto-electro-elastic materials with one or more cracks subjected to SH waves. We assume that the material properties vary in one and the same way, described by an inhomogeneity function. The boundary value problem is reduced to a system of integro-differential equationsmore » based on the existence of fundamental solutions. Different inhomogeneity classes are used to obtain a wave equation with constant coefficients. Radon transform is applied to derive the fundamental solution in a closed form. Program code in FORTRAN 77 is developed and validated using available examples from literature. Simulations show the dependence of stress field concentration near the crack tips on the frequency of the applied time-harmonic load for different types of material inhomogeneity.« less

A computational fluid–structure interaction model to predict the biomechanical properties of the artificial functionally graded aorta

PubMed Central

Khosravi, Arezoo; Bani, Milad Salimi; Bahreinizade, Hossein; Karimi, Alireza

2016-01-01

In the present study, three layers of the ascending aorta in respect to the time and space at various blood pressures have been simulated. Two well-known commercial finite element (FE) software have used to be able to provide a range of reliable numerical results while independent on the software type. The radial displacement compared with the time as well as the peripheral stress and von Mises stress of the aorta have calculated. The aorta model was validated using the differential quadrature method (DQM) solution and, then, in order to design functionally graded materials (FGMs) with different heterogeneous indexes for the artificial vessel, two different materials have been employed. Fluid–structure interaction (FSI) simulation has been carried out on the FGM and a natural vessel of the human body. The heterogeneous index defines the variation of the length in a function. The blood pressure was considered to be a function of both the time and location. Finally, the response characteristics of functionally graded biomaterials (FGBMs) models with different values of heterogeneous material parameters were determined and compared with the behaviour of a natural vessel. The results showed a very good agreement between the numerical findings of the FGM materials and that of the natural vessel. The findings of the present study may have implications not only to understand the performance of different FGMs in bearing the stress and deformation in comparison with the natural human vessels, but also to provide information for the biomaterials expert to be able to select a suitable material as an implant for the aorta. PMID:27836981

The effect of multi-directional nanocomposite materials on the vibrational response of thick shell panels with finite length and rested on two-parameter elastic foundations

NASA Astrophysics Data System (ADS)

Tahouneh, Vahid; Naei, Mohammad Hasan

2016-03-01

The main purpose of this paper is to investigate the effect of bidirectional continuously graded nanocomposite materials on free vibration of thick shell panels rested on elastic foundations. The elastic foundation is considered as a Pasternak model after adding a shear layer to the Winkler model. The panels reinforced by randomly oriented straight single-walled carbon nanotubes are considered. The volume fractions of SWCNTs are assumed to be graded not only in the radial direction, but also in axial direction of the curved panel. This study presents a 2-D six-parameter power-law distribution for CNTs volume fraction of 2-D continuously graded nanocomposite that gives designers a powerful tool for flexible designing of structures under multi-functional requirements. The benefit of using generalized power-law distribution is to illustrate and present useful results arising from symmetric, asymmetric and classic profiles. The material properties are determined in terms of local volume fractions and material properties by Mori-Tanaka scheme. The 2-D differential quadrature method as an efficient numerical tool is used to discretize governing equations and to implement boundary conditions. The fast rate of convergence of the method is shown and results are compared against existing results in literature. Some new results for natural frequencies of the shell are prepared, which include the effects of elastic coefficients of foundation, boundary conditions, material and geometrical parameters. The interesting results indicate that a graded nanocomposite volume fraction in two directions has a higher capability to reduce the natural frequency than conventional 1-D functionally graded nanocomposite materials.

Materials Organization, Planning, and Homework Completion in Middle School Students with ADHD: Impact on Academic Performance.

PubMed

Langberg, Joshua M; Epstein, Jeffery N; Girio, Erin L; Becker, Stephen P; Vaughn, Aaron J; Altaye, Mekibib

2011-06-01

This study evaluated the homework functioning of middle school students with ADHD to determine what aspects are most predictive of school grades and the best source (e.g., parents or teachers) for obtaining this information. Students with ADHD in grades 5-8 ( N = 57) and their parents and teachers completed the Children's Organization Skills Scales (COSS) to measure materials organization, planning, and time-management, and parents completed the Homework Problems Checklist (HPC) to examine homework completion and homework materials management behaviors. Regression analyses revealed that parent-rated homework materials management and teacher-rated memory and materials management were the best predictors of school grades. These findings suggest that organization of materials is a critical component of the homework completion process for students with ADHD and an important target for intervention. Teachers were the best source of information regarding materials organization and planning, whereas parents were a valuable source of information for specific homework materials management problems.

Materials Organization, Planning, and Homework Completion in Middle School Students with ADHD: Impact on Academic Performance

PubMed Central

Langberg, Joshua M.; Epstein, Jeffery N.; Girio, Erin L.; Becker, Stephen P.; Vaughn, Aaron J.; Altaye, Mekibib

2013-01-01

This study evaluated the homework functioning of middle school students with ADHD to determine what aspects are most predictive of school grades and the best source (e.g., parents or teachers) for obtaining this information. Students with ADHD in grades 5–8 (N = 57) and their parents and teachers completed the Children’s Organization Skills Scales (COSS) to measure materials organization, planning, and time-management, and parents completed the Homework Problems Checklist (HPC) to examine homework completion and homework materials management behaviors. Regression analyses revealed that parent-rated homework materials management and teacher-rated memory and materials management were the best predictors of school grades. These findings suggest that organization of materials is a critical component of the homework completion process for students with ADHD and an important target for intervention. Teachers were the best source of information regarding materials organization and planning, whereas parents were a valuable source of information for specific homework materials management problems. PMID:23577045

Fabrication and characterization of epoxy/silica functionally graded composite material

NASA Astrophysics Data System (ADS)

Misra, N.; Kapusetti, G.; Pattanayak, D. K.; Kumar, A.

2011-09-01

Increased use of composites in aerospace and defense application induces the search for heat resistant material. In present study silica reinforced epoxy functionally graded material using quartz fabric is prepared with different thickness. The gradation in silica : epoxy matrix is maintained with one side pure epoxy to opposite side pure silica. Thermal and mechanical behaviour of the composites were studied. It was found that the temperature gradient of 350°C to 950°C could be maintained for 2 to 5 min if the thickness of insulating silica layer is increased from 0.5 mm to 16 mm. Mechanical properties such as flexural modulus and strength of FGM composites were also evaluated. Strength and modulus decreased with increase of insulating layer.

Thermoelastic analysis of non-uniform pressurized functionally graded cylinder with variable thickness using first order shear deformation theory(FSDT) and perturbation method

NASA Astrophysics Data System (ADS)

Khoshgoftar, M. J.; Mirzaali, M. J.; Rahimi, G. H.

2015-11-01

Recently application of functionally graded materials(FGMs) have attracted a great deal of interest. These materials are composed of various materials with different micro-structures which can vary spatially in FGMs. Such composites with varying thickness and non-uniform pressure can be used in the aerospace engineering. Therefore, analysis of such composite is of high importance in engineering problems. Thermoelastic analysis of functionally graded cylinder with variable thickness under non-uniform pressure is considered. First order shear deformation theory and total potential energy approach is applied to obtain the governing equations of non-homogeneous cylinder. Considering the inner and outer solutions, perturbation series are applied to solve the governing equations. Outer solution for out of boundaries and more sensitive variable in inner solution at the boundaries are considered. Combining of inner and outer solution for near and far points from boundaries leads to high accurate displacement field distribution. The main aim of this paper is to show the capability of matched asymptotic solution for different non-homogeneous cylinders with different shapes and different non-uniform pressures. The results can be used to design the optimum thickness of the cylinder and also some properties such as high temperature residence by applying non-homogeneous material.

Effect of a Diffusion Zone on Fatigue Crack Propagation in Layered FGMs

NASA Astrophysics Data System (ADS)

Hauber, Brett; Brockman, Robert; Paulino, Glaucio

2008-02-01

Research into functionally graded materials (FGMs) has led to advances in our ability to analyze cracks. However, two prominent aspects remain relatively unexplored: 1) development and validation of modeling methods for fatigue crack propagation in FGMs, and 2) experimental validation of stress intensity models in engineered materials such as two phase monolithic and graded materials. This work addresses some of these problems for a limited set of conditions, material systems (e.g., Ti/TiB), and material gradients. Numerical analyses are conducted for single edge notch bend (SENB) specimens. Stress intensity factors are computed using the specialized finite element code I-Franc (Illinois Fracture Analysis Code), which is tailored for both homogeneous and graded materials, as well as Franc2DL and ABAQUS. Crack extension is considered by means of specified crack increments, together with fatigue evaluations to predict crack propagation life. Results will be used to determine linear material gradient parameters that are significant for prediction of fatigue crack growth behavior.

Efficient Reformulation of the Thermoelastic Higher-order Theory for Fgms

NASA Technical Reports Server (NTRS)

Bansal, Yogesh; Pindera, Marek-Jerzy; Arnold, Steven M. (Technical Monitor)

2002-01-01

Functionally graded materials (FGMs) are characterized by spatially variable microstructures which are introduced to satisfy given performance requirements. The microstructural gradation gives rise to continuously or discretely changing material properties which complicate FGM analysis. Various techniques have been developed during the past several decades for analyzing traditional composites and many of these have been adapted for the analysis of FGMs. Most of the available techniques use the so-called uncoupled approach in order to analyze graded structures. These techniques ignore the effect of microstructural gradation by employing specific spatial material property variations that are either assumed or obtained by local homogenization. The higher-order theory for functionally graded materials (HOTFGM) is a coupled approach developed by Aboudi et al. (1999) which takes the effect of microstructural gradation into consideration and does not ignore the local-global interaction of the spatially variable inclusion phase(s). Despite its demonstrated utility, however, the original formulation of the higher-order theory is computationally intensive. Herein, an efficient reformulation of the original higher-order theory for two-dimensional elastic problems is developed and validated. The use of the local-global conductivity and local-global stiffness matrix approach is made in order to reduce the number of equations involved. In this approach, surface-averaged quantities are the primary variables which replace volume-averaged quantities employed in the original formulation. The reformulation decreases the size of the global conductivity and stiffness matrices by approximately sixty percent. Various thermal, mechanical, and combined thermomechanical problems are analyzed in order to validate the accuracy of the reformulated theory through comparison with analytical and finite-element solutions. The presented results illustrate the efficiency of the reformulation and its advantages in analyzing functionally graded materials.

Materials Frontiers to Empower Quantum Computing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, Antoinette Jane; Sarrao, John Louis; Richardson, Christopher

This is an exciting time at the nexus of quantum computing and materials research. The materials frontiers described in this report represent a significant advance in electronic materials and our understanding of the interactions between the local material and a manufactured quantum state. Simultaneously, directed efforts to solve materials issues related to quantum computing provide an opportunity to control and probe the fundamental arrangement of matter that will impact all electronic materials. An opportunity exists to extend our understanding of materials functionality from electronic-grade to quantum-grade by achieving a predictive understanding of noise and decoherence in qubits and their originsmore » in materials defects and environmental coupling. Realizing this vision systematically and predictively will be transformative for quantum computing and will represent a qualitative step forward in materials prediction and control.« less

Thermomechanical response of metal-ceramic graded composites for high-temperature aerospace applications

NASA Astrophysics Data System (ADS)

Deierling, Phillip Eugene

Airframes operating in the hypersonic regime are subjected to complex structural and thermal loads. Structural loads are a result of aggressive high G maneuvers, rapid vehicle acceleration and deceleration, and dynamic pressure, while thermal loads are a result of aerodynamic heating. For such airframes, structural members are typically constructed from steel, titanium and nickel alloys. However, with most materials, rapid elevations in temperature lead to undesirable changes in material properties. In particular, reductions in strength and stiffness are observed, along with an increase in thermal conductivity, specific heat and thermal expansion. Thus, hypersonic airframes are typically designed with external insulation, active cooling or a thermal protection system (TPS) added to the structure to protect the underling material from the effects of temperature. Such thermal protection may consist of adhesively bonded, pinned, and bolted thermal protection layers over exterior panels. These types of attachments create abrupt changes in thermal expansion and stiffness that make the structure susceptible to cracking and debonding as well as adding mass to the airframe. One of the promising materials concepts for extreme environments that was introduced in the past is the so-called Spatially Tailored Advanced Thermal Structures (STATS). The concept of STATS is rooted in functionally graded materials (FGMs), in which a directional variation of material properties exists. These materials are essentially composites and consist of two or more phases of distinct materials in which the volume fractions of each phase continuously change in space. Here, the graded material will serve a dual-purpose role as both the structural/skin member and thermal management with the goal of reducing the weight of the structure while maintaining structural soundness. This is achieved through the ability to tailor material properties to create a desired or enhanced thermomechanical response through spatial variation (e.g. grading). The objective of this study is to present a computational framework for modeling and evaluating the thermomechanical response of STATS and FGMs for highly maneuverable hypersonic (Mach > 5) airframes. To meet the objective of this study, four key steps have been defined to study the thermomechanical response of such materials in extreme environments. They involve: (1) modeling of graded microstructures; (2) validation of analytical and numerical modeling techniques for graded microstructures; (3) determination of effective properties of variable composition composites; (4) parametric studies to evaluate the performance of FGMs for use in the hypersonic operating environment; (5) optimization of the material spatial grading in hypersonic panels aiming to improve the thermomechanical performance. Modeling of graded microstructures, representing particulate reinforced FGMs, has been accomplished using power law distribution functions to specify the spatial variation of the constituents. Artificial microstructures consisting of disks and spheres have been generated using developed algorithms. These algorithms allow for the creation of dense packing fractions up to 0.61 and 0.91 for 2D and 3D geometry, respectively. Effective properties of FGMs are obtained using micromechanics models and finite element analysis of representative volume elements (RVEs). Two approaches have been adopted and compared to determine the proper RVE for materials with graded microstructures. In the first approach, RVEs are generated by considering regions that have a uniform to slow variation in material composition (i.e., constant volume fraction), resulting in statistically homogenous piecewise RVEs of the graded microstructure neglecting interactions from neighboring cells. In the second approach, continuous RVEs are generated by considering the entire FGM. Here it is presumed that modeling of the complete variation in a microstructure may influence the surrounding layers due to the interactions of varying material composition, particularly when there is a steep variation in material composition along the grading direction. To determine these effects of interlayer interactions, FGM microstructures were generated using three different types of material grading functions, linear, quadratic and square root, providing uniform, gradual and steep variations, respectively. Two- and three-dimensional finite element analysis was performed to determine the effective temperature-dependent material properties of the composite over a wide temperature range. The outcome of the computational analysis show that the similar effective properties are obtained by each of the modeling approaches. Furthermore, the obtained computational results for effective elastic, thermal, and thermal expansion properties are consistent with the known analytical bounds. Resulting effective temperature-dependent material properties were used to evaluate the time-dependent thermostructural response and effectiveness of FGM structural panels. Structural panels are subjected to time- and spatial-dependent thermal and mechanical loads resulting from hypersonic flight over a representative trajectory. Mechanical loads are the by-product of aggressive maneuvering at high air speeds and angles of attack. Thermal loads as a result of aerodynamic heating are applied to the material systems as laminar, turbulent and transitional heat flux on the outer surface. Laminar and turbulent uniform heat fluxes are used to evaluate the effectiveness of FGM panels graded in the through-thickness direction only. Transitional heat fluxes are used to evaluate the effectiveness of FGMs graded in two principal directions, e.g., through-thickness and the surface parallel to flow. The computational results indicate that when subjected to uniform surface heat flux, the graded material system can eliminate through-thickness temperature gradients that are otherwise present in traditional thermal protection systems. Furthermore, two-dimensional graded material systems can also eliminate through-thickness temperature gradients and significantly reduce in-plane surface temperature gradients when subjected to non-uniform surface aerodynamic heating.

Vibration control of beams using constrained layer damping with functionally graded viscoelastic cores: theory and experiments

NASA Astrophysics Data System (ADS)

El-Sabbagh, A.; Baz, A.

2006-03-01

Conventionally, the viscoelastic cores of Constrained Layer Damping (CLD) treatments are made of materials that have uniform shear modulus. Under such conditions, it is well-recognized that these treatments are only effective near their edges where the shear strains attain their highest values. In order to enhance the damping characteristics of the CLD treatments, we propose to manufacture the cores from Functionally Graded ViscoElastic Materials (FGVEM) that have optimally selected gradient of the shear modulus over the length of the treatments. With such optimized distribution of the shear modulus, the shear strain can be enhanced, and the energy dissipation can be maximized. The theory governing the vibration of beams treated with CLD, that has functionally graded viscoelastic cores, is presented using the finite element method (FEM). The predictions of the FEM are validated experimentally for plain beams, beams treated conventional CLD, and beams with CLD/FGVEM of different configurations. The obtained results indicate a close agreement between theory and experiments. Furthermore, the obtained results demonstrate the effectiveness of the new class of CLD with functionally graded cores in enhancing the energy dissipation over the conventional CLD over a broad frequency band. Extension of the proposed one-dimensional beam/CLD/FGVEM system to more complex structures is a natural extension to the present study.

Functionally Graded Materials Database

NASA Astrophysics Data System (ADS)

Kisara, Katsuto; Konno, Tomomi; Niino, Masayuki

2008-02-01

Functionally Graded Materials Database (hereinafter referred to as FGMs Database) was open to the society via Internet in October 2002, and since then it has been managed by the Japan Aerospace Exploration Agency (JAXA). As of October 2006, the database includes 1,703 research information entries with 2,429 researchers data, 509 institution data and so on. Reading materials such as "Applicability of FGMs Technology to Space Plane" and "FGMs Application to Space Solar Power System (SSPS)" were prepared in FY 2004 and 2005, respectively. The English version of "FGMs Application to Space Solar Power System (SSPS)" is now under preparation. This present paper explains the FGMs Database, describing the research information data, the sitemap and how to use it. From the access analysis, user access results and users' interests are discussed.

Suitability of Different Food Grade Materials for the Encapsulation of Some Functional Foods Well Reported for Their Advantages and Susceptibility.

PubMed

Wani, Touseef Ahmed; Shah, Adil Gani; Wani, Sajad Mohd; Wani, Idrees Ahmed; Masoodi, Farooq Ahmad; Nissar, Nazia; Shagoo, Mudasir Ahmad

2016-11-17

Functional foods find a very important place in the modern era, where different types of cancer, diabetes, cardiovascular diseases, etc. are on a high. Irrespective of the abundance of bioactive components in different fruits and vegetables, their low solubility in aqueous solution, vulnerability to destruction in different environmental and gastrointestinal conditions and a low intestinal absorption becomes a concern. Because it is quite difficult to commercialize non food materials for the food encapsulation purposes due to their safety concerns in the human body, scientists in the recent times have come up with the idea of encapsulating the different bioactive components in different food grade materials that are able to safeguard these bioactive components against the different environmental and gastrointestinal conditions and ensure their safe and targeted delivery at their absorption sites. Different food grade encapsulation materials including various oligosaccharides, polysaccharides (starch, cyclodextrins, alginates, chitosan, gum arabic, and carboxymethyl cellulose) and proteins and their suitability for encapsulating various bioactive components like flavonoids (catechins, rutin, curcumin, hesperetin, and vanillin), nonflavonoids (resveratrol), carotenoids (β-carotene, lycopene, and lutein), and fatty acids (fish oil, flaxseed oil, and olive oil) of high medical and nutritional value are reviewed here.

Roll Compaction/Dry Granulation of Dibasic Calcium Phosphate Anhydrous-Does the Morphology of the Raw Material Influence the Tabletability of Dry Granules?

PubMed

Grote, Simon; Kleinebudde, Peter

2018-04-01

The influence of raw material particle morphology on the tabletabilty of dry granules was investigated. Therefore, dibasic calcium phosphate anhydrous was used as a model material. One milled grade, 2 agglomerated grades with different porosities, and a functionalized structure, that is, an agglomerate formed by very small primary particles, were included. Particle size, density, and specific surface area of raw materials were measured. The starting materials and 2 fractions of dry granules were compressed to tablets. The tabletability of granules was compared to that of the powders and the influence of specific compaction force, granule size, and lubrication on tablet tensile strength was evaluated. All materials showed a loss in tabletability induced by a previous compaction step but to a varying extent. Only in case of the functionalized calcium phosphate morphology, this effect depended on the specific compaction force. In contrast to the other materials, the tabletability of functionalized calcium phosphate was influenced by the granule size. This effect was not related to an overlubrication as internal and external lubrication resulted in similar tensile strengths. A clear influence of the particle morphology on tablet strength was demonstrated by the study. The functionalized structure showed aspects of a more plastic deformation behavior. The functionalized dibasic calcium phosphate and the more porous agglomerate performed as potential filler/binder in the field of roll compaction/dry granulation. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Piezoelectricity above the Curie temperature? Combining flexoelectricity and functional grading to enable high-temperature electromechanical coupling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mbarki, R.; Baccam, N.; Dayal, Kaushik

Most technologically relevant ferroelectrics typically lose piezoelectricity above the Curie temperature. This limits their use to relatively low temperatures. In this Letter, exploiting a combination of flexoelectricity and simple functional grading, we propose a strategy for high-temperature electromechanical coupling in a standard thin film configuration. We use continuum modeling to quantitatively demonstrate the possibility of achieving apparent piezoelectric materials with large and temperature-stable electromechanical coupling across a wide temperature range that extends significantly above the Curie temperature. With Barium and Strontium Titanate, as example materials, a significant electromechanical coupling that is potentially temperature-stable up to 900 °C is possible.

Scale-dependent effects on wave propagation in magnetically affected single/double-layered compositionally graded nanosize beams

NASA Astrophysics Data System (ADS)

Ebrahimi, Farzad; Barati, Mohammad Reza

2018-04-01

This article deals with the wave propagation analysis of single/double layered functionally graded (FG) size-dependent nanobeams in elastic medium and subjected to a longitudinal magnetic field employing nonlocal elasticity theory. Material properties of nanobeam change gradually according to the sigmoid function. Applying an analytical solution, the acoustical and optical dispersion relations are explored for various wave number, nonlocality parameter, material composition, elastic foundation constants, and magnetic field intensity. It is found that frequency and phase velocity of waves propagating in S-FGM nanobeam are significantly affected by these parameters. Also, presence of cut-off and escape frequencies in wave propagation analysis of embedded S-FGM nanobeams is investigated.

Effect of gradient dielectric coefficient in a functionally graded material (FGM) substrate on the propagation behavior of love waves in an FGM-piezoelectric layered structure.

PubMed

Cao, Xiaoshan; Shi, Junping; Jin, Feng

2012-06-01

The propagation behavior of Love waves in a layered structure that includes a functionally graded material (FGM) substrate carrying a piezoelectric thin film is investigated. Analytical solutions are obtained for both constant and gradient dielectric coefficients in the FGM substrate. Numerical results show that the gradient dielectric coefficient decreases phase velocity in any mode, and the electromechanical coupling factor significantly increases in the first- and secondorder modes. In some modes, the difference in Love waves' phase velocity between these two types of structure might be more than 1%, resulting in significant differences in frequency of the surface acoustic wave devices.

Test Method for the Fatigue Life of Layered TiB/Ti Functionally Graded Beams Subjected to Fully Reversed Bending

NASA Astrophysics Data System (ADS)

Byrd, Larry; Rickerd, Greg; Wyen, Travis; Cooley, Glenn; Quast, Jeff

2008-02-01

Sonic fatigue of aircraft is characterized by fully reversed bending of components subjected to acoustic excitation. This problem is compounded in high temperature environments because solutions for acoustics which tend to result in stiff structures make thermal problems worse. Conversely solutions to the thermal problem which allow expansion often fail in the presence of high acoustic levels. Errors in fatigue life prediction in the combined environment often range from a factor of 4 to 10. This results in either heavy, overly stiff structure or premature failure. This work will test the hypothesis that the fatigue life of a layered functionally graded material (FGM) will be dominated by the failure of the stiffest outer layer. This is based on the observation that for isotropic materials the life is approximately 90% crack initiation and only 10% crack growth before failure. Four sets of cantilever specimens will be tested using an electro-mechanical shaker for base excitation. The excitation will be narrow band random around the fundamental frequency. Two sets of specimens are of uniform composition consisting of 85%TiB/Ti and two are graded specimens consisting of layers that vary from commercially pure titanium to 85%TiB/Ti. Strain vs number of cycles to failure curves will be generated with both constant amplitude sine and narrow band random around the fundamental frequency excitation. The results will be examined to compare life of the uniform material to the functionally graded material. Also to be studied will be the use of Miner's rule to predict the fatigue life of the randomly excited specimens.

Functional grading of mineral and collagen in the attachment of tendon to bone.

PubMed

Genin, Guy M; Kent, Alistair; Birman, Victor; Wopenka, Brigitte; Pasteris, Jill D; Marquez, Pablo J; Thomopoulos, Stavros

2009-08-19

Attachment of dissimilar materials is a major challenge because high levels of localized stress may develop at their interfaces. An effective biologic solution to this problem exists at one of nature's most extreme interfaces: the attachment of tendon (a compliant, structural "soft tissue") to bone (a stiff, structural "hard tissue"). The goal of our study was to develop biomechanical models to describe how the tendon-to-bone insertion derives its mechanical properties. We examined the tendon-to-bone insertion and found two factors that give the tendon-to-bone transition a unique grading in mechanical properties: 1), a gradation in mineral concentration, measured by Raman spectroscopy; and 2), a gradation in collagen fiber orientation, measured by polarized light microscopy. Our measurements motivate a new physiological picture of the tissue that achieves this transition, the tendon-to-bone insertion, as a continuous, functionally graded material. Our biomechanical model suggests that the experimentally observed increase in mineral accumulation within collagen fibers can provide significant stiffening of the partially mineralized fibers, but only for concentrations of mineral above a "percolation threshold" corresponding to formation of a mechanically continuous mineral network within each collagen fiber (e.g., the case of mineral connectivity extending from one end of the fiber to the other). Increasing dispersion in the orientation distribution of collagen fibers from tendon to bone is a second major determinant of tissue stiffness. The combination of these two factors may explain the nonmonotonic variation of stiffness over the length of the tendon-to-bone insertion reported previously. Our models explain how tendon-to-bone attachment is achieved through a functionally graded material composition, and provide targets for tissue engineered surgical interventions and biomimetic material interfaces.

Static Analysis of Functionally Graded Composite Beams

NASA Astrophysics Data System (ADS)

Das, S.; Sarangi, S. K.

2016-09-01

This paper presents a study of functionally graded (FG) composite beam. The FG material for the beam is considered to be composed of different layers of homogeneous material. The fiber volume fraction corresponding to each layer is calculated by considering its variation along the thickness direction (z) according to a power law. Accordingly, the effective properties of the homogeneous layers are estimated and a beam composed of this FG material is modelled using the commercially available ANSYS software. The solid 186 layered structural solid element has been used for discretization of the model of the FG beam. The model developed is validated by comparing the results with those numerical results available in literature. Results are presented for simply supported and fixed boundary conditions for the FG beam. The stress distribution across the thickness of the FG composite beam has also been analyzed.

Thermoelastic Theory for the Response of Materials Functionally Graded in Two Directions with Applications to the Free-Edge Problem

NASA Technical Reports Server (NTRS)

Aboudi, Jacob; Pindera, Marek-Jerzy; Arnold, Steven M.

1995-01-01

A recently developed micromechanical theory for the thermoelastic response of functionally graded composites with nonuniform fiber spacing in the through-thickness direction is further extended to enable analysis of material architectures characterized by arbitrarily nonuniform fiber spacing in two directions. In contrast to currently employed micromechanical approaches applied to functionally graded materials, which decouple the local and global effects by assuming the existence of a representative volume element at every point within the composite, the new theory explicitly couples the local and global effects. The analytical development is based on volumetric averaging of the various field quantities, together with imposition of boundary and interfacial conditions in an average sense. Results are presented that illustrate the capability of the derived theory to capture local stress gradients at the free edge of a laminated composite plate due to the application of a uniform temperature change. It is further shown that it is possible to reduce the magnitude of these stress concentrations by a proper management of the microstructure of the composite plies near the free edge. Thus by an appropriate tailoring of the microstructure it is possible to reduce or prevent the likelihood of delamination at free edges of standard composite laminates.

An evaluation of a coupled microstructural approach for the analysis of functionally graded composites via the finite-element method

NASA Technical Reports Server (NTRS)

Pindera, Marek-Jerzy; Dunn, Patrick

1995-01-01

A comparison is presented between the predictions of the finite-element analysis and a recently developed higher-order theory for functionally graded materials subjected to a thorough-thickness temperature gradient. In contrast to existing micromechanical theories that utilize classical (i.e., uncoupled) homogenization schemes to calculate micro-level and macro-level stress and displacement fields in materials with uniform or nonuniform fiber spacing (i.e., functionally graded materials), the new theory explicitly couples the microstructural details with the macrostructure of the composite. Previous thermo-elastic analysis has demonstrated that such coupling is necessary when: the temperature gradient is large with respect to the dimension of the reinforcement; the characteristic dimension of the reinforcement is large relative to the global dimensions of the composite and the number of reinforcing fibers or inclusions is small. In these circumstances, the standard micromechanical analyses based on the concept of the representative volume element used to determine average composite properties produce questionable results. The comparison between the predictions of the finite-element method and the higher-order theory presented herein establish the theory's accuracy in predicting thermal and stress fields within composites with a finite number of fibers in the thickness direction subjected to a thorough-thickness thermal gradient.

Biological response on a titanium implant-grade surface functionalized with modular peptides☆

PubMed Central

Yazici, H.; Fong, H.; Wilson, B.; Oren, E.E.; Amos, F.A.; Zhang, H.; Evans, J.S.; Snead, M.L.; Sarikaya, M.; Tamerler, C.

2015-01-01

Titanium (Ti) and its alloys are among the most successful implantable materials for dental and orthopedic applications. The combination of excellent mechanical and corrosion resistance properties makes them highly desirable as endosseous implants that can withstand a demanding biomechanical environment. Yet, the success of the implant depends on its osteointegration, which is modulated by the biological reactions occurring at the interface of the implant. A recent development for improving biological responses on the Ti-implant surface has been the realization that bifunctional peptides can impart material binding specificity not only because of their molecular recognition of the inorganic material surface, but also through their self-assembly and ease of biological conjugation properties. To assess peptide-based functionalization on bioactivity, the present authors generated a set of peptides for implant-grade Ti, using cell surface display methods. Out of 60 unique peptides selected by this method, two of the strongest titanium binding peptides, TiBP1 and TiBP2, were further characterized for molecular structure and adsorption properties. These two peptides demonstrated unique, but similar molecular conformations different from that of a weak binder peptide, TiBP60. Adsorption measurements on a Ti surface revealed that their disassociation constants were 15-fold less than TiBP60. Their flexible and modular use in biological surface functionalization were demonstrated by conjugating them with an integrin recognizing peptide motif, RGDS. The functionalization of the Ti surface by the selected peptides significantly enhanced the bioactivity of osteoblast and fibroblast cells on implant-grade materials. PMID:23159566

Electron Beam Freeform Fabrication of Titanium Alloy Gradient Structures

NASA Technical Reports Server (NTRS)

Brice, Craig A.; Newman, John A.; Bird, Richard Keith; Shenoy, Ravi N.; Baughman, James M.; Gupta, Vipul K.

2014-01-01

Historically, the structural optimization of aerospace components has been done through geometric methods. A monolithic material is chosen based on the best compromise between the competing design limiting criteria. Then the structure is geometrically optimized to give the best overall performance using the single material chosen. Functionally graded materials offer the potential to further improve structural efficiency by allowing the material composition and/or microstructural features to spatially vary within a single structure. Thus, local properties could be tailored to the local design limiting criteria. Additive manufacturing techniques enable the fabrication of such graded materials and structures. This paper presents the results of a graded material study using two titanium alloys processed using electron beam freeform fabrication, an additive manufacturing process. The results show that the two alloys uniformly mix at various ratios and the resultant static tensile properties of the mixed alloys behave according to rule-of-mixtures. Additionally, the crack growth behavior across an abrupt change from one alloy to the other shows no discontinuity and the crack smoothly transitions from one crack growth regime into another.

Vibration analysis of FG cylindrical shells with power-law index using discrete singular convolution technique

NASA Astrophysics Data System (ADS)

Mercan, Kadir; Demir, Çiǧdem; Civalek, Ömer

2016-01-01

In the present manuscript, free vibration response of circular cylindrical shells with functionally graded material (FGM) is investigated. The method of discrete singular convolution (DSC) is used for numerical solution of the related governing equation of motion of FGM cylindrical shell. The constitutive relations are based on the Love's first approximation shell theory. The material properties are graded in the thickness direction according to a volume fraction power law indexes. Frequency values are calculated for different types of boundary conditions, material and geometric parameters. In general, close agreement between the obtained results and those of other researchers has been found.

Low transient thermal stress turbine engine components

DOEpatents

Shi, Jun [Glastonbury, CT; Schmidt, Wayde R [Pomfret Center, CT

2011-06-28

A turbine vane includes a platform; and at least one airfoil mounted to the platform and having a trailing edge and a leading edge, wherein the vane is composed of a functionally graded material having a first material and a second material, wherein the trailing edge includes a greater amount of the first material than the second material, and the leading edge includes a greater amount of the second material than the first material.

Grade 12 Diploma Examination, English 33. Part B: Reading. (Multiple Choice). Readings Booklet. 1988 Edition.

ERIC Educational Resources Information Center

Alberta Dept. of Education, Edmonton.

Intended for students taking Grade 12 Diploma Examinations in English 33 in Alberta, Canada, this reading test is designed to be administered with a questions booklet. The following short selections taken from fiction, nonfiction, poetry, drama, and day-to-day functional materials are included: (1) "M is for Mother" (Marjorie Riddle);…

Effects of gravity on combustion synthesis of functionally graded biomaterials

NASA Astrophysics Data System (ADS)

Castillo, M.; Moore, J. J.; Schowengerdt, F. D.; Ayers, R. A.; Zhang, X.; Umakoshi, M.; Yi, H. C.; Guigne, J. Y.

2003-07-01

Combustion synthesis, or self-propagating, high temperature synthesis is currently being used at the Colorado School of Mines to produce advanced materials for biomedical applications. These biomaterials include ceramic, intermetallic, and metal-matrix composites for applications ranging from structural to oxidation- and wear-resistant materials, e.g., TiC-Ti, TiC-Cr 3C 2, MOSi 2-SiC, NiAl-TiB 2, to engineered porous composites, e.g., B 4C-Al 2O 3, Ti-TiB x, Ni-Ti, Ca 3(P0 4) 2 and glass-ceramic composites, e.g., CaO-SiO 2-BaO-Al 2O 3-TiB 2. The goal of the functionally graded biomaterials project is to develop new materials, graded in porosity and composition, which will combine the desirable mechanical properties of implant, e.g., NiTi, with the bone-growth enhancement properties of porous biodegradable ceramics, e.g., Ca 3(PO 4) 2. Recent experiments on the NASA parabolic flight (KC-135) aircraft have shown that gravity plays an important role in controlling the structure and properties of materials produced by combustion synthesis. The results of these studies, which will be presented at the conference, will provide valuable input to the design of experiments to be done in Space-DRUMS TM, a containerless materials processing facility scheduled to be placed on the International Space Station in 2003.

Modern Languages for Communication. Teaching the Curriculum: Checkpoint A, Grades K-6. Topics, Objectives, Activities in French, German, Italian, and Spanish.

ERIC Educational Resources Information Center

Yonkers City School District, NY.

The modern language curriculum guide for grades K-6 is designed to correlate with Checkpoint A of the New York State Syllabus. It presents major topics, listing instructional objectives, functions, skill areas, suggested instructional materials, suggested activities, cultural content, and games, songs, and puzzles. Introductory sections outline…

Developmental Changes in the Access of Referential and Associative Information by Pictures and Words. Research Bulletin #9.

ERIC Educational Resources Information Center

Marschark, Marc; Carroll, Elizabeth

Three experiments examined referential and associative linkages in memory as a function of stimulus and response material formats. Second grade, sixth grade, and university students were the subjects. In Experiment 1, subjects pointed to either the picture or printed name of a stimulus corresponding to the name or picture, respectively, pointed to…

Thermal effect on the dynamic response of axially functionally graded beam subjected to a moving harmonic load

NASA Astrophysics Data System (ADS)

Wang, Yuewu; Wu, Dafang

2016-10-01

Dynamic response of an axially functionally graded (AFG) beam under thermal environment subjected to a moving harmonic load is investigated within the frameworks of classical beam theory (CBT) and Timoshenko beam theory (TBT). The Lagrange method is employed to derive the equations of thermal buckling for AFG beam, and then with the critical buckling temperature as a parameter the Newmark-β method is adopted to evaluate the dynamic response of AFG beam under thermal environments. Admissible functions denoting transverse displacement are expressed in simple algebraic polynomial forms. Temperature-dependency of material constituent is considered. The rule of mixture (Voigt model) and Mori-Tanaka (MT) scheme are used to evaluate the beam's effective material properties. A ceramic-metal AFG beam with immovable boundary condition is considered as numerical illustration to show the thermal effects on the dynamic behaviors of the beam subjected to a moving harmonic load.

Microstructure-property relationships and constitutive response of plastically graded case hardened steels

NASA Astrophysics Data System (ADS)

Klecka, Michael A.

Case hardened materials, popularly used in many demanding engineering applications such as bearings, gears, and wear/impact surfaces, have high surface hardness and a gradient in material properties (hardness, yield strength, etc.) as a function of depth; therefore, they behave as plastically graded materials. In the current study, two different commercially available case carburized steels along with two through hardened steels are characterized to obtain relationships among the volume fraction of subsurface carbides, indentation hardness, elastic modulus, and yield strength as a function of depth. A variety of methods including microindentation, nanoindentation, ultrasonic measurements, compression testing, rule of mixtures, and upper and lower bound models are used to determine the relationships for elastic modulus and compare the experimental results with model predictions. In addition, the morphology, composition, and properties of the carbide particles are also determined. The gradient in hardness with depth in graded materials is commonly determined using microindentation on the cross-section of the material which contains the gradation in microstructure or composition. In the current study, a novel method is proposed to predict the hardness gradient profile using solely surface indentations at a range of loads. The method does not require the graded material to be sectioned, and has practical utility in the surface heat-treatment industry. For a material with a decreasing gradient in hardness, higher indent loads result in a lower measured hardness due to the influence of the softer subsurface layers. A power-law model is presented which relates the measured surface indentation hardness under increasing load to the subsurface gradient in hardness. A coordinated experimental and numerical study is presented to extract the constitutive response of graded materials, utilizing relationships between hardness, plastic deformation, and strain hardening response. The average plastic strain induced by an indent is shown to be an effective measure of the representative plastic strain, which is used in order to relate hardness to yield strength in both virgin and plastically deformed materials. It is shown that the two carburized steels contain gradients in yield strength, but constant strain hardening exponent with depth. The resulting model of material behavior is used to characterize the influence of specific gradients in material properties on the surface indentation behavior under increasing indentation loads. It is also shown that the response of the material is not greatly influenced by strain hardening exponent, while a gradient in strain hardening ability only has minimal impact. Gradients in elastic properties are also shown to have negligible influence for a fixed gradient in hardness. The depth of subsurface plastic deformation is shown to increase with sharper gradients in hardness, but is not altered by gradients in elastic properties. The proposed approach is not specific to case hardened materials and can be used to determine the subsurface hardness gradient for any graded material.

Probing the Natural World, Volume 1.

ERIC Educational Resources Information Center

Burkman, Ernest

These materials represent the first third of a coordinated science program for grades seven through nine. The materials have been prepared according to the following Intermediate Science Curriculum Study rationale: (1) science at the junior-high-school level should serve a general education function, and (2) both processes and concepts should be…

HOTCFGM-1D: A Coupled Higher-Order Theory for Cylindrical Structural Components with Through-Thickness Functionally Graded Microstructures

NASA Technical Reports Server (NTRS)

Pindera, Marek-Jerzy; Aboudi, Jacob

1998-01-01

The objective of this three-year project was to develop and deliver to NASA Lewis one-dimensional and two-dimensional higher-order theories, and related computer codes, for the analysis, optimization and design of cylindrical functionally graded materials/structural components for use in advanced aircraft engines (e.g., combustor linings, rotor disks, heat shields, blisk blades). To satisfy this objective, a quasi one-dimensional version of the higher-order theory, HOTCFGM-1D, and four computer codes based on this theory, for the analysis, design and optimization of cylindrical structural components functionally graded in the radial direction were developed. The theory is applicable to thin multi-phased composite shell/cylinders subjected to macroscopically axisymmetric thermomechanical and inertial loading applied uniformly along the axial direction such that the overall deformation is characterized by a constant average axial strain. The reinforcement phases are uniformly distributed in the axial and circumferential directions, and arbitrarily distributed in the radial direction, thereby allowing functional grading of the internal reinforcement in this direction.

Quadratic Solid⁻Shell Finite Elements for Geometrically Nonlinear Analysis of Functionally Graded Material Plates.

PubMed

Chalal, Hocine; Abed-Meraim, Farid

2018-06-20

In the current contribution, prismatic and hexahedral quadratic solid⁻shell (SHB) finite elements are proposed for the geometrically nonlinear analysis of thin structures made of functionally graded material (FGM). The proposed SHB finite elements are developed within a purely 3D framework, with displacements as the only degrees of freedom. Also, the in-plane reduced-integration technique is combined with the assumed-strain method to alleviate various locking phenomena. Furthermore, an arbitrary number of integration points are placed along a special direction, which represents the thickness. The developed elements are coupled with functionally graded behavior for the modeling of thin FGM plates. To this end, the Young modulus of the FGM plate is assumed to vary gradually in the thickness direction, according to a volume fraction distribution. The resulting formulations are implemented into the quasi-static ABAQUS/Standard finite element software in the framework of large displacements and rotations. Popular nonlinear benchmark problems are considered to assess the performance and accuracy of the proposed SHB elements. Comparisons with reference solutions from the literature demonstrate the good capabilities of the developed SHB elements for the 3D simulation of thin FGM plates.

Methodology for Selection of Optimum Light Stringers in Functionally Graded Panels Designed for Prescribed Fundamental Frequency or Buckling Load

NASA Astrophysics Data System (ADS)

Birman, Victor; Byrd, Larry W.

2008-02-01

The interest to functionally graded materials (FGM) and structures has been generated by their potential advantages, including enhanced thermal properties, reduced or eliminated delamination concerns, a potential for an improved stress distribution, etc. Various aspects of the processing, design, micromechanics and analysis of FGM have been outlined in a number of reviews, mentioned here are [1-3]. In particular, functionally graded panels may be advantageous compared to their conventional counterparts in numerous applications. However, a typical FGM panel is asymmetric about its middle plane resulting in lower buckling loads and fundamental frequencies as well as higher stresses and deformations than the counterpart with a symmetric distribution of the same constituents. The reduced stiffness of FGM panels can be compensated by reinforcing them with stringers. For example, metallic stringers at the metal-rich surface of a FGM ceramic-metal panel may provide an efficient solution enabling a designer to increase both buckling loads as well as natural frequencies. The list of studies on optimization of FGM is extensive as could be anticipated for such tailored structural elements. For example, recent papers by Batra and his collaborators present optimization of the natural frequencies of a FGM plate through material grading [4] and through the graded fiber orientation [5]. The present paper is concerned with an optimum design of the system of stringers for a specified FGM panel. The task is to design the lightest system of stringers enabling the panel to achieve prescribed buckling loads or fundamental frequency.

[Correspondence analysis between traditional commercial specifications and quantitative quality indices of Notopterygii Rhizoma et Radix].

PubMed

Jiang, Shun-Yuan; Sun, Hong-Bing; Sun, Hui; Ma, Yu-Ying; Chen, Hong-Yu; Zhu, Wen-Tao; Zhou, Yi

2016-03-01

This paper aims to explore a comprehensive assessment method combined traditional Chinese medicinal material specifications with quantitative quality indicators. Seventy-six samples of Notopterygii Rhizoma et Radix were collected on market and at producing areas. Traditional commercial specifications were described and assigned, and 10 chemical components and volatile oils were determined for each sample. Cluster analysis, Fisher discriminant analysis and correspondence analysis were used to establish the relationship between the traditional qualitative commercial specifications and quantitative chemical indices for comprehensive evaluating quality of medicinal materials, and quantitative classification of commercial grade and quality grade. A herb quality index (HQI) including traditional commercial specifications and chemical components for quantitative grade classification were established, and corresponding discriminant function were figured out for precise determination of quality grade and sub-grade of Notopterygii Rhizoma et Radix. The result showed that notopterol, isoimperatorin and volatile oil were the major components for determination of chemical quality, and their dividing values were specified for every grade and sub-grade of the commercial materials of Notopterygii Rhizoma et Radix. According to the result, essential relationship between traditional medicinal indicators, qualitative commercial specifications, and quantitative chemical composition indicators can be examined by K-mean cluster, Fisher discriminant analysis and correspondence analysis, which provide a new method for comprehensive quantitative evaluation of traditional Chinese medicine quality integrated traditional commodity specifications and quantitative modern chemical index. Copyright© by the Chinese Pharmaceutical Association.

Relationship between cognitive functions and prevalence of fatigue in elementary and junior high school students.

PubMed

Mizuno, Kei; Tanaka, Masaaki; Fukuda, Sanae; Imai-Matsumura, Kyoko; Watanabe, Yasuyoshi

2011-06-01

Fatigue is a common complaint among elementary and junior high school students, and is related to poor academic performance. Since grade-dependent development of cognitive functions also influences academic performance, we attempted to determine whether cognitive functions were associated with the prevalence of fatigue. Participants were 148 elementary school students from 4th- to 6th-grades and 152 junior high school students from 7th- to 9th-grades. Participants completed a questionnaire about fatigue (Japanese version of the Chalder Fatigue Scale) and paper-and-pencil and computerized cognitive tests which could evaluate the abilities of motor processing, immediate, delayed and working memory, selective, divided and alternative attention, retrieve learned material, and spatial construction. We found that in multivariate logistic regression analyses adjusted for grade and gender, slow motor processing was positively correlated with the prevalence of fatigue in the elementary school students and decreases in working memory and divided and alternative attention processing were positively correlated with the prevalence of fatigue in the junior high school students. The grade-dependent development of cognitive function influences the severity of fatigue in elementary and junior high school students. Copyright © 2010 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Exploration of Public Service Occupations. Curriculum Guide.

ERIC Educational Resources Information Center

California State Dept. of Education, Sacramento. Div. of Vocational Education.

The guide contains the basic concepts and instructional materials recommended for the exploration of public service occupations at the junior high school level (grades 7-9). The materials can be used as a separate course or can be integrated into the subject areas suggested. The 17 units deal with the functioning of Federal, State, and local…

Foreign Object Damage in a Gas-Turbine Grade Silicon Nitride by Spherical Projectiles of Various Materials

NASA Technical Reports Server (NTRS)

Choi, Sung R.; Racz, Zsolt; Bhatt, Ramakrishna T.; Brewer, David N.

2006-01-01

Assessments of foreign object damage (FOD) of a commercial, gas-turbine grade, in situ toughened silicon nitride ceramic (AS800, Honeywell Ceramics Components) were made using four different projectile materials at ambient temperature. AS800 flexure target specimens rigidly supported were impacted at their centers in a velocity range from 50 to 450 m/s by spherical projectiles with a diameter of 1.59 mm. Four different projectile materials were used including hardened steel, annealed steel, silicon nitride ceramic, and brass. Post-impact strength of each target specimen impacted was determined as a function of impact velocity to appraise the severity of local impact damage. For a given impact velocity, the degree of strength degradation was greatest for ceramic balls, least for brass balls, and intermediate for annealed and hardened steel balls. For steel balls, hardened projectiles yielded more significant impact damage than annealed counterparts. The most important material parameter affecting FOD was identified as hardness of projectiles. Impact load as a function of impact velocity was quasi-statically estimated based on both impact and static indentation associated data.

Higher-Order Theory: Structural/MicroAnalysis Code (HOTSMAC) Developed

NASA Technical Reports Server (NTRS)

Arnold, Steven M.

2002-01-01

The full utilization of advanced materials (be they composite or functionally graded materials) in lightweight aerospace components requires the availability of accurate analysis, design, and life-prediction tools that enable the assessment of component and material performance and reliability. Recently, a new commercially available software product called HOTSMAC (Higher-Order Theory--Structural/MicroAnalysis Code) was jointly developed by Collier Research Corporation, Engineered Materials Concepts LLC, and the NASA Glenn Research Center under funding provided by Glenn's Commercial Technology Office. The analytical framework for HOTSMAC is based on almost a decade of research into the coupled micromacrostructural analysis of heterogeneous materials. Consequently, HOTSMAC offers a comprehensive approach for analyzing/designing the response of components with various microstructural details, including certain advantages not always available in standard displacement-based finite element analysis techniques. The capabilities of HOTSMAC include combined thermal and mechanical analysis, time-independent and time-dependent material behavior, and internal boundary cells (e.g., those that can be used to represent internal cooling passages, see the preceding figure) to name a few. In HOTSMAC problems, materials can be randomly distributed and/or functionally graded (as shown in the figure, wherein the inclusions are distributed linearly), or broken down by strata, such as in the case of thermal barrier coatings or composite laminates.

Functionally graded polymeric materials: A brif review of current fabrication methods and introduction of a novel fabrication method.

PubMed

Almasi, Davood; Sadeghi, Maliheh; Lau, Woei Jye; Roozbahani, Fatemeh; Iqbal, Nida

2016-07-01

The present work reviews the current fabrication methods of the functionally graded polymeric material (FGPM) and introduces a novel fabrication method that is versatile in applications as compared to those of existing used methods. For the first time electrophoresis was used to control the distribution of the tetracycline hydrochloride (TC) in a film made of polylactic acid (PLA), aiming to induce antimicrobial effect on the film prepared. The elemental analysis on the film surface showed that by employing electrophoresis force, higher amount of TC was detected near the top surface of the film. Results also showed that the FGPM samples with higher percentage of the TC on the film surface were highly effective to minimize the growth of Escherichia coli. These findings are useful and important to improve dispersion quality of the particles in the composite material and further enhance its antibacterial property. Copyright © 2016 Elsevier B.V. All rights reserved.

Optimum gradient material for a functionally graded dental implant using metaheuristic algorithms.

PubMed

Sadollah, Ali; Bahreininejad, Ardeshir

2011-10-01

Despite dental implantation being a great success, one of the key issues facing it is a mismatch of mechanical properties between engineered and native biomaterials, which makes osseointegration and bone remodeling problematical. Functionally graded material (FGM) has been proposed as a potential upgrade to some conventional implant materials such as titanium for selection in prosthetic dentistry. The idea of an FGM dental implant is that the property would vary in a certain pattern to match the biomechanical characteristics required at different regions in the hosting bone. However, matching the properties does not necessarily guarantee the best osseointegration and bone remodeling. Little existing research has been reported on developing an optimal design of an FGM dental implant for promoting long-term success. Based upon remodeling results, metaheuristic algorithms such as the genetic algorithms (GAs) and simulated annealing (SA) have been adopted to develop a multi-objective optimal design for FGM implantation design. The results are compared with those in literature. Copyright © 2011 Elsevier Ltd. All rights reserved.

Free Vibration Characteristics of Functionally Graded Pre-twisted Conical Shells under Rotation

NASA Astrophysics Data System (ADS)

Das, Apurba; Karmakar, Amit

2017-06-01

This article deals with effect of rotation and pretwist angle on free vibration characteristics of functionally graded conical shells. The dynamic equilibrium equation is derived from Lagrange's equation neglecting the Coriolis effect for moderate rotational speeds. The materials properties of conical shell are varied with a power-law distribution of the volume fractions of their constituents through its thickness. Convergence studies are performed in respect of mesh sizes, and comparisons of the present solutions and those reported in open literature are provided to substantiate the accuracy of the proposed method. Computer codes developed to obtain the numerical results for the combined effects of twist angle and rotational speed on the natural frequencies of functionally graded conical shells. The mode shapes for a typical laminate configuration under different conditions are also illustrated. Numerical results are obtained for the non-dimensional fundamental (NDFF) and second frequencies (NDSF).

Thermal spraying of functionally graded calcium phosphate coatings for biomedical implants

NASA Astrophysics Data System (ADS)

Wang, Y.; Khor, K. A.; Cheang, P.

1998-03-01

Biomedical requirements in a prosthesis are often complex and diverse in nature. Biomaterials for implants have to display a wide range of adaptability to suit the various stages of the bio-integration process of any foreign material into the human body. Often, a combination of materials is needed. The preparation of a functionally graded bioceramic coating composed of essentially calcium phosphate compounds is explored. The coating is graded in accordance to adhesive strength, bioactivity, and bioresorbability. The bond coat on the Ti-6Al-4V stub is deposited with a particle range of the hydroxyapatite (HA) that will provide a high adhesive strength and bioactivity but have poor bioresorption properties. The top coat, however, is composed of predominantly α-tricalcium phosphate (α-TCP) that is highly bioresorbable. This arrangement has the propensity of allowing accelerated bio-integration of the coating by the body tissues as the top layer is rapidly resorbed, leaving the more bioactive intermediate layer to facilitate the much needed bioactive properties for proper osteoconduction. The processing steps and problems are highlighted, as well as the results of post-spray heat treatment.

User's Manual and Final Report for Hot-SMAC GUI Development

NASA Technical Reports Server (NTRS)

Yarrington, Phil

2001-01-01

A new software package called Higher Order Theory-Structural/Micro Analysis Code (HOT-SMAC) has been developed as an effective alternative to the finite element approach for Functionally Graded Material (FGM) modeling. HOT-SMAC is a self-contained package including pre- and post-processing through an intuitive graphical user interface, along with the well-established Higher Order Theory for Functionally Graded Materials (HOTFGM) thermomechanical analysis engine. This document represents a Getting Started/User's Manual for HOT-SMAC and a final report for its development. First, the features of the software are presented in a simple step-by-step example where a HOT-SMAC model representing a functionally graded material is created, mechanical and thermal boundary conditions are applied, the model is analyzed and results are reviewed. In a second step-by-step example, a HOT-SMAC model of an actively cooled metallic channel with ceramic thermal barrier coating is built and analyzed. HOT-SMAC results from this model are compared to recently published results (NASA/TM-2001-210702) for two grid densities. Finally, a prototype integration of HOTSMAC with the commercially available HyperSizer(R) structural analysis and sizing software is presented. In this integration, local strain results from HyperSizer's structural analysis are fed to a detailed HOT-SMAC model of the flange-to-facesheet bond region of a stiffened panel. HOT-SMAC is then used to determine the peak shear and peel (normal) stresses between the facesheet and bonded flange of the panel and determine the "free edge" effects.

Graded porous polyurethane foam: a potential scaffold for oro-maxillary bone regeneration.

PubMed

Giannitelli, S M; Basoli, F; Mozetic, P; Piva, P; Bartuli, F N; Luciani, F; Arcuri, C; Trombetta, M; Rainer, A; Licoccia, S

2015-06-01

Bone tissue engineering applications demand for biomaterials offering a substrate for cell adhesion, migration, and proliferation, while inferring suitable mechanical properties to the construct. In the present study, polyurethane (PU) foams were synthesized to develop a graded porous material-characterized by a dense shell and a porous core-for the treatment of oro-maxillary bone defects. Foam was synthesized via a one-pot reaction starting from a polyisocyanate and a biocompatible polyester diol, using water as a foaming agent. Different foaming conditions were examined, with the aim of creating a dense/porous functional graded material that would perform at the same time as an osteoconductive scaffold for bone defect regeneration and as a membrane-barrier to gingival tissue ingrowth. The obtained PU was characterized in terms of morphological and mechanical properties. Biocompatibility assessment was performed in combination with bone-marrow-derived human mesenchymal stromal cells (hBMSCs). Our findings confirm that the material is potentially suitable for guided bone regeneration applications. Copyright © 2015 Elsevier B.V. All rights reserved.

Free vibration of fully functionally graded carbon nanotube reinforced graphite/epoxy laminates

NASA Astrophysics Data System (ADS)

Kuo, Shih-Yao

2018-03-01

This study provides the first-known vibration analysis of fully functionally graded carbon nanotube reinforced hybrid composite (FFG-CNTRHC) laminates. CNTs are non-uniformly distributed to reinforce the graphite/epoxy laminates. Some CNT distribution functions in the plane and thickness directions are proposed to more efficiently increase the stiffening effect. The rule of mixtures is modified by considering the non-homogeneous material properties of FFG-CNTRHC laminates. The formulation of the location dependent stiffness matrix and mass matrix is derived. The effects of CNT volume fraction and distribution on the natural frequencies of FFG-CNTRHC laminates are discussed. The results reveal that the FFG layout may significantly increase the natural frequencies of FFG-CNTRHC laminate.

Manufacturing of PZT-nickel functionally graded piezoelectric ceramics

NASA Astrophysics Data System (ADS)

Rubio, Wilfredo M.; Silva, Emílio C. N.; Buiochi, Flávio

2012-05-01

A recent approach for designing and manufacturing piezoelectric ceramics consists of using the functionally graded materials (FGM) concept. In this work, nickel (Ni) is used to generate a new PZT-Ni graded ceramic and its dynamic behavior is experimentally explored. The PZT-Ni graded ceramic is manufactured by using the technique of Spark Plasma Sintering (SPS). The ceramic is graded from the top to the bottom surface (along 6 mm of thickness). Specifically, five layers of green powders are sintered: 100 wt% PZT-5A, 90 wt% PZT-5A and 10 wt% Ni, 80 wt% PZT-5A and 20 wt% Ni, 70 wt% PZT-5A and 30 wt% Ni, 60 wt% PZT-5A and 40 wt% Ni. Thus, Ni is used as a second phase, which is added to a PZT-5A matrix, changing its concentration. No manufacturing defects or cracks or exfoliated layers are observed. However, graphite diffusion is observed from the graphite die into the graded ceramic, which does not affect its performance; hence, the ceramic contains enough piezoelectric properties, which allows its polarization and dynamic characterization by determining the impedance curve of the PZT-Ni graded ceramic. The PZT-Ni graded ceramic vibrates at 1.04 MHz, 1.55 MHz and 2.07 MHz.

ESF GROUND SUPPORT - MATERIAL DEDICATION ANALYSIS FOR STRUCTURAL STEEL AND ACCESSORIES FROM A COMMERCIAL GRADE SOURCE

DOE Office of Scientific and Technical Information (OSTI.GOV)

M.D. Stine

1996-01-23

The purpose of this analysis is to select the critical characteristics to be verified for steel sets and accessories and the verification methods to be implemented through a material dedication process for the procurement and use of commercial grade structural steel sets and accessories (which have a nuclear safety function) to be used in ground support (with the exception of alcove ground support and alcove opening framing, which are not addressed in this analysis) for the Exploratory Studies Facility (ESF) Topopah Spring (TS) Loop. The ESF TS Loop includes the North Ramp, Main Drift, and South Ramp underground openings.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Ch.; Gao, X. W.; Sladek, J.

This paper reports our recent research works on crack analysis in continuously non-homogeneous and linear elastic functionally graded materials. A meshless boundary element method is developed for this purpose. Numerical examples are presented and discussed to demonstrate the efficiency and the accuracy of the present numerical method, and to show the effects of the material gradation on the crack-opening-displacements and the stress intensity factors.

Compressive evaluation of homogeneous and graded epoxy-glass particulate composites.

PubMed

Seaglar, J; Rousseau, C-E

2015-04-01

The propagation of stress waves in epoxy-glass particulate composites and graded materials was studied experimentally. Materials tested in this study consisted of an epoxy matrix with various concentrations of spherical glass particles having a mean diameter of 42μm. Plate impact experiments were performed using a gas gun. Embedded within the specimens were manganin stress gauges used to record propagating compressive longitudinal stress waves through the material. High strain rate experiments using a Split Hopkinson Pressure Bar (SHPB) apparatus were also performed to evaluate the dynamic strength of the specimens, while quasi-static compression tests were undertaken to characterize their quasi-static behavior. Ultrasonic wave speed measurements were carried-out in order to obtain additional material properties and characterize the gradation in functionally graded materials (FGM). It was found that low volume fractions of particles are detrimental to the performance of the material under impact loading, while concentrations in the range of about 30 to 45% by volume exhibit characteristics of higher degrees of scattering. This suggests that materials in this latter range would be more effective in the thwarting of destructive shock waves than the homogeneous matrix material. Impact testing of FGM specimens suggests that impact loading on the stiff (high volume fraction) face results in much higher levels of scattering. Therefore, such materials would be effective for use in light weight armor or as shielding materials due to their effective attenuation of mechanical impulses. Copyright © 2015 Elsevier B.V. All rights reserved.

Technical data on new engineering products

NASA Astrophysics Data System (ADS)

1985-02-01

New grades of permanently magnetic materials; automatic digital radiolocator; bench winder; analog induction gauge; programmable pulse generator; portable defibrillators; pipe welders; two-component electromagnetic log; sulphur content analyzer; peristaltic pumps; function generators; welding manipulator; and tonsiometer are described.

Mathematics Through Science, Part III: An Experimental Approach to Functions. Teacher's Commentary. Revised Edition.

ERIC Educational Resources Information Center

Bolduc, Elroy J., Jr.; And Others

The purpose of this project is to teach learning and understanding of mathematics at the ninth grade level through the use of science experiments. This part of the program contains significant amounts of material normally found in a beginning algebra class. The material should be found useful for classes in general mathematics as a preparation for…

Preparation of Functionally Graded Materials (FGMs) Using Coal Fly Ash and NiCr-Based Alloy Powder by Spark Plasma Sintering (SPS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaneko, Gen-yo; Kitagawa, Hiroyuki; Hasezaki, Kazuhiro

2008-02-15

Functionally Graded Materials (FGMs) were prepared by spark plasma sintering (SPS) using coal fly ash and NiCr alloy powder. The coal fly ash was produced by the Misumi Coal Thermal Power Station (Chugoku Electric Power Co., Inc.), with 80 wt% nickel and 20 wt% chromium (Fukuda Metal Foil and Powder Co., Ltd.) used as source materials. The sintering temperature in the graphite die was 1000 deg. C. X-ray diffraction patterns of the sintered coal fly ash materials indicated that mullite (3Al{sub 2}O{sub 3}{center_dot}2SiO{sub 2}) and silica (SiO{sub 2}) phases were predominant. Direct joining of coal fly ash and NiCr causesmore » fracture at the interface. This is due to the mismatch in the thermal expansion coefficients (CTE). A crack in the FGM was observed between the two layers with a CTE difference of over 4.86x10{sup -6} K{sup -1}, while a crack in the FGM was difficult to detect when the CTE difference was less than 2.77x10{sup -6} K{sup -1}.« less

[Grading of the functional sport shoe parameter "cushioning" and "forefoot flexibility" on running shoes].

PubMed

Kleindienst, F I; Krabbe, B; Walther, M; Brüggemann, G-P

2006-03-01

On nearly every running event a heterogeneous structure of participants regarding body height and body weight can be observed. This study should figure out whether the running shoe manufacturers will consider this anthropometric variability. Moreover it should be investigated the runners needs based on different anthropometrics regarding preferred cushioning and forefoot flexibility properties. In order to check whether the running shoe manufacturers will apply a grading pattern, a dynamic material study with conventional running shoes in different sizes was conducted. In a second step a field study in Middle Europe and North America with 244 female and 227 male runners was organized. Every subject had to run and evaluate 7 different shoe modifications. Based on the material study it is to state, that the running shoe manufacturers currently do not consider a systematic grading of cushioning and forefoot flexibility properties. In contrast to this, the field study reveals the necessity to grade these properties. A shoe size dependent and a geographic grading concept are suggested. It is supposed, that the application of these grading concepts do not only provide a comfort improvement, but they also contribute to a reduction of joint loads of the lower extremities and consequently to a prevention of overuse injuries.

Stochastic Investigation of Natural Frequency for Functionally Graded Plates

NASA Astrophysics Data System (ADS)

Karsh, P. K.; Mukhopadhyay, T.; Dey, S.

2018-03-01

This paper presents the stochastic natural frequency analysis of functionally graded plates by applying artificial neural network (ANN) approach. Latin hypercube sampling is utilised to train the ANN model. The proposed algorithm for stochastic natural frequency analysis of FGM plates is validated and verified with original finite element method and Monte Carlo simulation (MCS). The combined stochastic variation of input parameters such as, elastic modulus, shear modulus, Poisson ratio, and mass density are considered. Power law is applied to distribute the material properties across the thickness. The present ANN model reduces the sample size and computationally found efficient as compared to conventional Monte Carlo simulation.

Spatially Tailored and Functionally Graded Light-Weight Structures for Optimum Mechanical Performance

DTIC Science & Technology

2008-01-15

grading scheme involves embedding particles only in the outer layers of a laminate , achieving maximal increases in bending stiffness with a minimum...by Eq. (19), with d=2. Longitudinal-transverse shear modulus The shear modulus for distortion of the laminate in axes with one direction aligned...The effective Poisson’s ratio νeLT is dictated by the other material constants of the laminate (Hill, 1964; Torquato, 2001): 12 νe LT = ν f + ν

The use of functionally graded dental crowns to improve biocompatibility: a finite element analysis.

PubMed

Mahmoudi, Mojtaba; Saidi, Ali Reza; Hashemipour, Maryam Alsadat; Amini, Parviz

2018-02-01

In post-core crown restorations, the significant mismatch between stiffness of artificial crowns and dental tissues leads to stress concentration at the interfaces. The aim of the present study was to reduce the destructive stresses by using a class of inhomogeneous materials called functionally graded materials (FGMs). For the purpose of the study, a 3-dimentional computer model of a premolar tooth and its surrounding tissues were generated. A post-core crown restoration with various crown materials, homogenous and FGM materials, were simulated and analyzed by finite element method. Finite element and statistical analysis showed that, in case of oblique loading, a significant difference (p < 0.05) was found at the maximum von Mises stresses of the crown margin between FGM and homogeneous crowns. The maximum von Mises stresses of the crown margin generated by FGM crowns were lower than those generated by homogenous crowns (70.8 vs. 46.3 MPa) and alumina crown resulted in the highest von Mises stress at the crown margin (77.7 MPa). Crown materials of high modulus of elasticity produced high stresses at the cervical region. FGM crowns may reduce the stress concentration at the cervical margins and consequently reduce the possibility of fracture.

Oxidation Resitant HfC-TaC Rocket Thruster for High Performance Propellants

NASA Technical Reports Server (NTRS)

Patterson, Mark

1999-01-01

The purpose of this reasearch effort was to develop high temperature, oxidation resistant thrusters which would lessen the thruster cooling requirements, resulting in increased performance and longer life for onboard propulsion systems for spacecraft. This research effort focussed on developing ceramic matrix composites (CMCs) for this application, and specifically investigated the use of HfC stabilized with TaC. This material composition can potentially operate in a stoichiometric oxygen to hydrogen ratio at a temperature of 5000 deg F (2760 deg C) in a radiatively cooled mode. Various compositions of Hafnium Carbide (HfC) and Tantalum Carbide (TaC) were deposited by chemical vapor deposition (CVD) and tested, in an attempt to identify the composition which offered the best oxidation resistance. Although it was identified that small amounts of TaC appeared to offer improved oxidation resistance over HfC alone, an optimal composition was not identified. A 251bf thruster was fabricated from a novel CMC sandwich construction with a HfC-TaC matrix, and survived two test firings, each of 5 seconds before a failure in the injector caused the run to be aborted. It was not possible to control the relative stoichiometry of the HfC and TaC composition throughout the reactor due to the large difference in the thermodynamics of the HfC and TaC formation from their respective chlorides. This also resulted in an inability to infiltrate TaC into the preform under the experimental conditions investigated. Other material compositions were fabricated and tested and two material systems; HfC-SiC functionally graded to C(sub f)/C and Re functionally graded to C(sub f)/C were selected for further testing. These functionally graded composites have use in a number of propulsion applications presently of interest to NASA and the defense industry. Their ability to withstand extremely hostile thermal environments and the light-weight and high-strength exhibited from the C(sub f)/C composite make these materials particularly suited for these applications. In the Phase III which is presently underway, Re functionally graded to C(sub f)/C is being further developed and tested for application in the thrust cells for the Linear Aerospike Engine for the X33 and RLV.

A Modified Kirchhoff plate theory for Free Vibration analysis of functionally graded material plates using meshfree method

NASA Astrophysics Data System (ADS)

Nguyen Van Do, Vuong

2018-04-01

In this paper, a modified Kirchhoff theory is presented for free vibration analyses of functionally graded material (FGM) plate based on modified radial point interpolation method (RPIM). The shear deformation effects are taken account into modified theory to ignore the locking phenomenon of thin plates. Due to the proposed refined plate theory, the number of independent unknowns reduces one variable and exists with four degrees of freedom per node. The simulated free vibration results employed by the modified RPIM are compared with the other analytical solutions to verify the effectiveness and the accuracy of the developed mesh-free method. Detail parametric studies of the proposed method are then conducted including the effectiveness of thickness ratio, boundary condition and material inhomogeneity on the sample problems of square plates. Results illustrated that the modified mesh-free RPIM can effectively predict the numerical calculation as compared to the exact solutions. The obtained numerical results are indicated that the proposed method are stable and well accurate prediction to evaluate with other published analyses.

Mechanical and Thermal Analysis of Classical Functionally Graded Coated Beam

NASA Astrophysics Data System (ADS)

Toudehdehghan, Abdolreza; Mujibur Rahman, Md.; Tarlochan, Faris

2018-03-01

The governing equation of a classical rectangular coated beam made of two layers subjected to thermal and uniformly distributed mechanical loads are derived by using the principle of virtual displacements and based on Euler-Bernoulli deformation beam theory (EBT). The aim of this paper was to analyze the static behavior of clamped-clamped thin coated beam under thermo-mechanical load using MATLAB. Two models were considered for composite coated. The first model was consisting of ceramic layer as a coated and substrate which was metal (HC model). The second model was consisting of Functionally Graded Material (FGM) as a coated layer and metal substrate (FGC model). From the result it was apparent that the superiority of the FGC composite against conventional coated composite has been demonstrated. From the analysis, the stress level throughout the thickness at the interface of the coated beam for the FGC was reduced. Yet, the deflection in return was observed to increase. Therefore, this could cater to various new engineering applications where warrant the utilization of material that has properties that are well-beyond the capabilities of the conventional or yesteryears materials.

Love-type waves in functionally graded piezoelectric material (FGPM) sandwiched between initially stressed layer and elastic substrate

NASA Astrophysics Data System (ADS)

Saroj, Pradeep K.; Sahu, S. A.; Chaudhary, S.; Chattopadhyay, A.

2015-10-01

This paper investigates the propagation behavior of Love-type surface waves in three-layered composite structure with initial stress. The composite structure has been taken in such a way that a functionally graded piezoelectric material (FGPM) layer is bonded between initially stressed piezoelectric upper layer and an elastic substrate. Using the method of separation of variables, frequency equation for the considered wave has been established in the form of determinant for electrical open and short cases on free surface. The bisection method iteration technique has been used to find the roots of the dispersion relations which give the modes for electrical open and short cases. The effects of gradient variation of material constant and initial stress on the phase velocity of surface waves are discussed. Dependence of thickness on each parameter of the study has been shown explicitly. Study has been also done to show the existence of cut-off frequency. Graphical representation has been done to exhibit the findings. The obtained results are significant for the investigation and characterization of Love-type waves in FGPM-layered media.

On propagation of axisymmetric waves in pressurized functionally graded elastomeric hollow cylinders

NASA Astrophysics Data System (ADS)

Wu, Bin; Su, Yipin; Liu, Dongying; Chen, Weiqiu; Zhang, Chuanzeng

2018-05-01

Soft materials can be designed with a functionally graded (FG) property for specific applications. Such material inhomogeneity can also be found in many soft biological tissues whose functionality is only partly understood to date. In this paper, we analyze the axisymmetric guided wave propagation in a pressurized FG elastomeric hollow cylinder. The cylinder is subjected to a combined action of axial pre-stretch and pressure difference applied to the inner and outer cylindrical surfaces. We consider both torsional waves and longitudinal waves propagating in the FG cylinder made of incompressible isotropic elastomer, which is characterized by the Mooney-Rivlin strain energy function but with the material parameters varying with the radial coordinate in an affine way. The pressure difference generates an inhomogeneous deformation field in the FG cylinder, which dramatically complicates the superimposed wave problem described by the small-on-large theory. A particularly efficient approach is hence employed which combines the state-space formalism for the incremental wave motion with the approximate laminate or multi-layer technique. Dispersion relations for the two types of axisymmetric guided waves are then derived analytically. The accuracy and convergence of the proposed approach is validated numerically. The effects of the pressure difference, material gradient, and axial pre-stretch on both the torsional and the longitudinal wave propagation characteristics are discussed in detail through numerical examples. It is found that the frequency of axisymmetric waves depends nonlinearly on the pressure difference and the material gradient, and an increase in the material gradient enhances the capability of the pressure difference to adjust the wave behavior in the FG cylinder. This work provides a theoretical guidance for characterizing FG soft materials by in-situ ultrasonic nondestructive evaluation and for designing tunable waveguides via material tailoring along with an adjustment of the pre-stretch and pressure difference.

Damage tolerant functionally graded materials for advanced wear and friction applications

NASA Astrophysics Data System (ADS)

Prchlik, Lubos

The research work presented in this dissertation focused on processing effects, microstructure development, characterization and performance evaluation of composite and graded coatings used for friction and wear control. The following issues were addressed. (1) Definition of prerequisites for a successful composite and graded coating formation by means of thermal spraying. (2) Improvement of characterization methods available for homogenous thermally sprayed coating and their extension to composite and graded materials. (3) Development of novel characterization methods specifically for FGMs, with a focus on through thickness property measurement by indentation and in-situ curvature techniques. (4) Design of composite materials with improved properties compared to homogenous coatings. (5) Fabrication and performance assessment of FGM with improved wear and impact damage properties. Materials. The materials studied included several material systems relevant to low friction and contact damage tolerant applications: MO-Mo2C, WC-Co cermets as materials commonly used sliding components of industrial machinery and NiCrAlY/8%-Yttria Partially Stabilized Zirconia composites as a potential solution for abradable sections of gas turbines and aircraft engines. In addition, uniform coatings such as molybdenum and Ni5%Al alloy were evaluated as model system to assess the influence of microstructure variation onto the mechanical property and wear response. Methods. The contact response of the materials was investigated through several techniques. These included methods evaluating the relevant intrinsic coating properties such as elastic modulus, residual stress, fracture toughness, scratch resistance and tests measuring the abrasion and friction-sliding behavior. Dry-sand and wet two-body abrasion testing was performed in addition to traditional ball on disc sliding tests. Among all characterization techniques the spherical indentation deserved most attention and enabled to measure elastic-plastic properties of uniform and graded structures. In-situ curvature method used for residual stress and elastic modulus measurement was extended from uniform coatings to coatings with compositional/property gradients. Properties of composite and graded materials were measured using the inverse analysis. Conclusions. The specifics of the elastic-plastic response for thermally sprayed coatings were demonstrated. These included the strain dependence of elastic modulus and damage accumulation related to unloading/reloading loop formation. The measurement of elastic-plastic characteristics of composite coatings revealed the mixing and bonding mechanisms unique for thermally sprayed materials. Microstructural and compositional factors governing the frictional vs. abrasion response of carbide-metallic composite coatings were described. The measurement of abrasion resistance and friction sliding properties demonstrated that grading of cermet and ceramic coatings by adding moderate amount of metallic alloys can enhance elastic-properties radically and have a beneficial effect onto the coating performance.

High Thermal Conductivity and High Wear Resistance Tool Steels for cost-effective Hot Stamping Tools

NASA Astrophysics Data System (ADS)

Valls, I.; Hamasaiid, A.; Padré, A.

2017-09-01

In hot stamping/press hardening, in addition to its shaping function, the tool controls the cycle time, the quality of the stamped components through determining the cooling rate of the stamped blank, the production costs and the feasibility frontier for stamping a given component. During the stamping, heat is extracted from the stamped blank and transported through the tool to the cooling medium in the cooling lines. Hence, the tools’ thermal properties determine the cooling rate of the blank, the heat transport mechanism, stamping times and temperature distribution. The tool’s surface resistance to adhesive and abrasive wear is also an important cost factor, as it determines the tool durability and maintenance costs. Wear is influenced by many tool material parameters, such as the microstructure, composition, hardness level and distribution of strengthening phases, as well as the tool’s working temperature. A decade ago, Rovalma developed a hot work tool steel for hot stamping that features a thermal conductivity of more than double that of any conventional hot work tool steel. Since that time, many complimentary grades have been developed in order to provide tailored material solutions as a function of the production volume, degree of blank cooling and wear resistance requirements, tool geometries, tool manufacturing method, type and thickness of the blank material, etc. Recently, Rovalma has developed a new generation of high thermal conductivity, high wear resistance tool steel grades that enable the manufacture of cost effective tools for hot stamping to increase process productivity and reduce tool manufacturing costs and lead times. Both of these novel grades feature high wear resistance and high thermal conductivity to enhance tool durability and cut cycle times in the production process of hot stamped components. Furthermore, one of these new grades reduces tool manufacturing costs through low tool material cost and hardening through readily available gas-quenching, whereas the other new grade enables a faster manufacturing of the tool at reduced cost by eliminating the time and money consuming high temperature hardening altogether. The latter newly developed grade can be hardened from a soft delivery state for easy machining to 52 HRc by way of a simple low temperature precipitation hardening. In this work, these new grades and the role of the tool material’s thermal, mechanical and tribological properties as well as their processing features will be discussed in light of enabling the manufacture of intelligent hot stamping tools.

Mechanical and microstructural characterization of W–Cu FGM fabricated by one-step sintering method through PM route

NASA Astrophysics Data System (ADS)

Gupta, Rajat; Kumar, Rohit; Chaubey, A. K.; Kanpara, Shailesh; Khirwadkar, S. S.

2018-03-01

Five layer W-Cu functionally graded material (FGM) for components in nuclear fusion application was fabricated by a one-step resistance sintering process, known as spark plasma sintering (SPS). In this study effect of sintering temperature (Ts) on physical, mechanical and surface property was investigated. Detailed microstructural study revealed that the graded structure of the composite layers with varying composition from 0 to 100 wt% W and Cu in opposite directions could be well densified after the SPS process. It also indicates that the fine microstructure within functionally graded layers can be maintained because of short sintering time. The sample sintered at 1050°C shows more than 90% theoretical density, hardness greater than 239±5 Hv and excellent surface scratch resistance. The result demonstrates that SPS is promising and more suitable process for fabrication of W-Cu FGM.

Investigation of static and dynamic behavior of functionally graded piezoelectric actuated Poly-Si micro cantilever probe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pandey, Vibhuti Bhushan; Parashar, Sandeep Kumar, E-mail: skparashar@rtu.ac.in

In the present paper a novel functionally graded piezoelectric (FGP) actuated Poly-Si micro cantilever probe is proposed for atomic force microscope. The shear piezoelectric coefficient d{sub 15} has much higher value than coupling coefficients d{sub 31} and d{sub 33}, hence in the present work the micro cantilever beam actuated by d{sub 15} effect is utilized. The material properties are graded in the thickness direction of actuator by a simple power law. A three dimensional finite element analysis has been performed using COMSOL Multiphysics® (version 4.2) software. Tip deflection and free vibration analysis for the micro cantilever probe has been done.more » The results presented in the paper shall be useful in the design of micro cantilever probe and their subsequent utilization in atomic force microscopes.« less

A Comparison of Four Techniques for Producing High-Grade Furniture Core Material From Low-Grade Yellow-Poplar

Treesearch

Philip A. Araman

1978-01-01

Four Methods of converting low-grade yellow-poplar lumber into high-grade furniture core material (lumber core) were compared. High-grade core material is used in tops, shelves, doors, and drawer fronts and only minor defects are allowed. Three gang-rip first and the conventional crosscut-first manufacturing sequences were evaluated in combination with 1 Common, 2A...

Easy assessment of the biocompatibility of Ni-Ti alloys by in vitro cell culture experiments on a functionally graded Ni-NiTi-Ti material.

PubMed

Bogdanski, Denise; Köller, Manfred; Müller, Dietmar; Muhr, Gert; Bram, Martin; Buchkremer, Hans Peter; Stöver, Detlev; Choi, Jongsik; Epple, Matthias

2002-12-01

The biocompatibility of nickel-titanium alloys was investigated by single-culture experiments on functionally graded samples with a stepwise change in composition from pure nickel to pure titanium, including an Ni-Ti shape memory alloy for a 50:50 mixture. This approach permitted a considerable decrease of experimental resources by simultaneously studying a full variation of composition. The results indicate a good biocompatibility for a nickel content up to about 50%. The cells used in the biocompatibility studies comprised osteoblast-like osteosarcoma cells (SAOS-2, MG-63), primary human osteoblasts (HOB), and murine fibroblasts (3T3).

Content, format, gender and grade level differences in elementary students' ability to read science materials as measured by the cloze procedure

NASA Astrophysics Data System (ADS)

Williams, Richard L.; Yore, Larry D.

Present instructional trends in science indicate a need to reexamine a traditional concern in science education: the readability of science textbooks. An area of reading research not well documented is the effect of color, visuals, and page layout on readability of science materials. Using the cloze readability method, the present study explored the relationships between page format, grade level, sex, content, and elementary school students ability to read science material. Significant relationships were found between cloze scores and both grade level and content, and there was a significant interaction effect between grade and sex in favor of older males. No significant relationships could be attributed to page format and sex. In the area of science content, biological materials were most difficult in terms of readability followed by earth science and physical science. Grade level data indicated that grade five materials were more difficult for that level than either grade four or grade six materials were for students at each respective level. In eight of nine cases, the science text materials would be classified at or near the frustration level of readability. The implications for textbook writers and publishers are that science reading materials need to be produced with greater attention to readability and known design principles regarding visual supplements. The implication for teachers is that students need direct instruction in using visual materials to increase their learning from text material. Present visual materials appear to neither help nor hinder the student to gain information from text material.

Action-at-a-distance metamaterials: Distributed local actuation through far-field global forces

NASA Astrophysics Data System (ADS)

Hedayati, R.; Mirzaali, M. J.; Vergani, L.; Zadpoor, A. A.

2018-03-01

Mechanical metamaterials are a sub-category of designer materials where the geometry of the material at the small-scale is rationally designed to give rise to unusual properties and functionalities. Here, we propose the concept of "action-at-a-distance" metamaterials where a specific pattern of local deformation is programmed into the fabric of (cellular) materials. The desired pattern of local actuation could then be achieved simply through the application of one single global and far-field force. We proposed graded designs of auxetic and conventional unit cells with changing Poisson's ratios as a way of making "action-at-a-distance" metamaterials. We explored five types of graded designs including linear, two types of radial gradients, checkered, and striped. Specimens were fabricated with indirect additive manufacturing and tested under compression, tension, and shear. Full-field strain maps measured with digital image correlation confirmed different patterns of local actuation under similar far-field strains. These materials have potential applications in soft (wearable) robotics and exosuits.

Japanese Language and Culture: 9-Year Program Classroom Assessment Materials, Grade 4

ERIC Educational Resources Information Center

Alberta Education, 2008

2008-01-01

This document is designed to provide assessment materials for specific Grade 4 outcomes in the Japanese Language and Culture Nine-year Program, Grades 4-5-6. The assessment materials are designed for the beginner level in the context of teaching for communicative competence. Grade 4 learning outcomes from the Japanese Language and Culture…

German Language and Culture: 9-Year Program Classroom Assessment Materials, Grade 4

ERIC Educational Resources Information Center

Alberta Education, 2008

2008-01-01

This document is designed to provide assessment materials for specific Grade 4 outcomes in the German Language and Culture Nine-year Program, Grades 4-5-6. The assessment materials are designed for the beginner level in the context of teaching for communicative competence. Grade 4 learning outcomes from the German Language and Culture Nine-year…

Punjabi Language and Culture: 9-Year Program Classroom Assessment Materials, Grade 4

ERIC Educational Resources Information Center

Alberta Education, 2008

2008-01-01

This document is designed to provide assessment materials for specific Grade 4 outcomes in the Punjabi Language and Culture Nine-year Program, Grades 4-5-6. The assessment materials are designed for the beginner level in the context of teaching for communicative competence. Grade 4 learning outcomes from the Punjabi Language and Culture Nine-year…

Executive function mediates prospective relationships between sleep duration and sedentary behavior in children.

PubMed

Warren, Christopher; Riggs, Nathaniel; Pentz, Mary Ann

2016-10-01

Childhood sedentary behavior has been linked to increased obesity risk. Prior work has identified associations between sedentary behavior, executive function (EF), and sleep. This study tested the hypothesis that reduced sleep duration may adversely impact EF and lead to increased childhood sedentary behavior. Southern California schoolchildren participating in the school-based health promotion program Pathways to Health (N=709) were assessed annually from 4th through 6th grades (2010-2013) on self-report measures of sedentary behavior, sleep duration, and executive function. A series of path models were specified treating average nightly sleep duration and weekend wake/bed-time shift at 4th grade as predictors of 6th grade sedentary behavior. Four EF subdomains were tested as potential mediators of longitudinal associations at 5th grade. Significant associations between average nightly sleep duration, EF and sedentary behavior were identified (p<0.05), adjusting for participant gender, physical activity, SES, ethnicity, program group assignment, and the presence/absence of parental screen time rules. Fifth grade overall EF (p<0.05)-and in particular the subdomains of inhibitory control (p<0.05) and organization of materials (p<0.01)-significantly mediated the relationship between 4th grade sleep duration and 6th grade sedentary behavior (p<0.05). Furthermore, delay of weekend bed- or wake-times relative to weekdays was prospectively associated with decreased overall EF (p<0.05), but not increased sedentary behavior (p=0.35 for bed-time delay; p=0.64 for wake-time delay), irrespective of average nightly sleep duration. Findings suggest that sleep promotion efforts may reduce children's sedentary behavior both directly and indirectly through changes in EF. Copyright © 2016 Elsevier Inc. All rights reserved.

Executive function mediates prospective relationships between sleep duration and sedentary behavior in children

PubMed Central

Warren, Christopher; Riggs, Nathaniel; Pentz, Mary Ann

2016-01-01

Childhood sedentary behavior has been linked to increased obesity risk. Prior work has identified associations between sedentary behavior, executive function (EF), and sleep. This study tested the hypothesis that reduced sleep duration may adversely impact EF and lead to increased childhood sedentary behavior. Southern California schoolchildren participating in the school-based health promotion program Pathways to Health (N = 709) were assessed annually from 4th through 6th grades (2010–2013) on self-report measures of sedentary behavior, sleep duration, and executive function. A series of path models were specified treating average nightly sleep duration and weekend wake/bed-time shift at 4th grade as predictors of 6th grade sedentary behavior. Four EF subdomains were tested as potential mediators of longitudinal associations at 5th grade. Significant associations between average nightly sleep duration, EF and sedentary behavior were identified (p < 0.05), adjusting for participant gender, physical activity, SES, ethnicity, program group assignment, and the presence/absence of parental screen time rules. Fifth grade overall EF (p < 0.05)—and in particular the subdomains of inhibitory control (p < 0.05) and organization of materials (p < 0.01)—significantly mediated the relationship between 4th grade sleep duration and 6th grade sedentary behavior (p < 0.05). Furthermore, delay of weekend bed- or wake-times relative to weekdays was prospectively associated with decreased overall EF (p < 0.05), but not increased sedentary behavior (p = 0.35 for bed-time delay; p = 0.64 for wake-time delay), irrespective of average nightly sleep duration. Findings suggest that sleep promotion efforts may reduce children’s sedentary behavior both directly and indirectly through changes in EF. PMID:27477059

Phonon impedance matching: minimizing interfacial thermal resistance of thin films

NASA Astrophysics Data System (ADS)

Polanco, Carlos; Zhang, Jingjie; Ghosh, Avik

2014-03-01

The challenge to minimize interfacial thermal resistance is to allow a broad band spectrum of phonons, with non-linear dispersion and well defined translational and rotational symmetries, to cross the interface. We explain how to minimize this resistance using a frequency dependent broadening matrix that generalizes the notion of acoustic impedance to the whole phonon spectrum including symmetries. We show how to ``match'' two given materials by joining them with a single atomic layer, with a multilayer material and with a graded superlattice. Atomic layer ``matching'' requires a layer with a mass close to the arithmetic mean (or spring constant close to the harmonic mean) to favor high frequency phonon transmission. For multilayer ``matching,'' we want a material with a broadening close to the geometric mean to maximize transmission peaks. For graded superlattices, a continuous sequence of geometric means translates to an exponentially varying broadening that generates a wide-band antireflection coating for both the coherent and incoherent limits. Our results are supported by ``first principles'' calculations of thermal conductance for GaAs / Gax Al1 - x As / AlAs thin films using the Non-Equilibrium Greens Function formalism coupled with Density Functional Perturbation Theory. NSF-CAREER (QMHP 1028883), NSF-IDR (CBET 1134311), XSEDE.

Wsbnd Cu functionally graded material: Low temperature fabrication and mechanical characterization

NASA Astrophysics Data System (ADS)

Yusefi, Ali; Parvin, Nader; Mohammadi, Hossein

2018-04-01

In this study, we fabricated and characterized a Wsbnd Cu functionally graded material (FGM) with 11 layers, including a pure copper layer. Samples were prepared by mixing a mechanically alloyed Nisbnd Mnsbnd Cu powder with W and Cu powders, stacking the powders, pressing the stacked layers, and finally sintering at 1000 °C. The utilization of a Nisbnd Mnsbnd Cu system may reduce the cost but without losing the good sintering behavior and physical and mechanical properties. The composition of the material was analyzed based on scanning electron microscopy images and by energy dispersive X-ray spectroscopy mapping, which indicated that in the presence of Ni and Mn, the Cu atoms could diffuse into the W particles. All of the layers had a very high relative density, thereby indicating their densification and excellent sintering behavior. We also found that the porosity values in the Cu phase remained unchanged at approximately 2.39% across the FGM. Mechanical measurements showed that the hardness (72%), modulus of elasticity (61%), and ultimate tensile strength (58%) increased with the W content across the Wsbnd Cu FGM, whereas the fracture toughness (KIC) varied in the opposite manner (minimum of 4.52 MPa/m0.5).

A comparative analysis of neurosurgical online education materials to assess patient comprehension.

PubMed

Agarwal, Nitin; Chaudhari, Amit; Hansberry, David R; Tomei, Krystal L; Prestigiacomo, Charles J

2013-10-01

Americans have increasingly utilized the internet as a first-line resource for a variety of information, including healthcare-oriented materials. Therefore, these online resources should be written at a level the average American can understand. Patient education resources specifically written for and available to the public were downloaded from the American Association of Neurological Surgeons website and assessed for their level of readability using the Flesch Reading Ease, Flesch-Kincaid Grade Level, Simple Measure of Gobbledygook Grading, Coleman-Liau Index, and Gunning-Fog Index. A total of 71 subsections from different neurosurgical specialties were reviewed, including Cerebrovascular, Spine and Peripheral Nerves, Neurotrauma and Critical Care, Pain, Pediatric, Stereotactic and Functional, and Tumor material. All neurosurgical subspecialty education material provided on the American Association of Neurological Surgeons website was uniformly written at a level that was too high, as assessed by all modalities. In order to reach a larger patient population, patient education materials on the American Association of Neurological Surgeons website should be revised with the goal of simplifying readability. Copyright © 2013 Elsevier Ltd. All rights reserved.

NEW EDUCATIONAL MATERIALS, PRE-KINDERGARTEN THROUGH GRADE TWELVE.

ERIC Educational Resources Information Center

ALLISON, MARY L., COMP.

THIS IS A COMPILATION OF EVALUATIONS AND REVIEWS WRITTEN BY TEACHERS, LIBRARIANS, AND CURRICULUM SPECIALISTS WHO HAVE TESTED THE MATERIALS. FROM PRE-KINDERGARTEN TO GRADE 12, BOOKS AND INSTRUCTIONAL MATERIALS FOR LANGUAGE ARTS, SOCIAL STUDIES, AND SCIENCE ARE REVIEWED. FOR GRADES 7 TO 12, MATERIALS ARE EVALUATED FOR ART AND MUSIC, HEALTH AND…

Most American Academy of Orthopaedic Surgeons' online patient education material exceeds average patient reading level.

PubMed

Eltorai, Adam E M; Sharma, Pranav; Wang, Jing; Daniels, Alan H

2015-04-01

Advancing health literacy has the potential to improve patient outcomes. The American Academy of Orthopaedic Surgeons' (AAOS) online patient education materials serve as a tool to improve health literacy for orthopaedic patients; however, it is unknown whether the materials currently meet the National Institutes of Health/American Medical Association's recommended sixth grade readability guidelines for health information or the mean US adult reading level of eighth grade. The purposes of this study were (1) to evaluate the mean grade level readability of online AAOS patient education materials; and (2) to determine what proportion of the online materials exceeded recommended (sixth grade) and mean US (eighth grade) reading level. Reading grade levels for 99.6% (260 of 261) of the online patient education entries from the AAOS were analyzed using the Flesch-Kincaid formula built into Microsoft Word software. Mean grade level readability of the AAOS patient education materials was 9.2 (SD ± 1.6). Two hundred fifty-one of the 260 articles (97%) had a readability score above the sixth grade level. The readability of the AAOS articles exceeded the sixth grade level by an average of 3.2 grade levels. Of the 260 articles, 210 (81%) had a readability score above the eighth grade level, which is the average reading level of US adults. Most of the online patient education materials from the AAOS had readability levels that are far too advanced for many patients to comprehend. Efforts to adjust the readability of online education materials to the needs of the audience may improve the health literacy of orthopaedic patients. Patient education materials can be made more comprehensible through use of simpler terms, shorter sentences, and the addition of pictures. More broadly, all health websites, not just those of the AAOS, should aspire to be comprehensible to the typical reader.

Engineering functionality gradients by dip coating process in acceleration mode.

PubMed

Faustini, Marco; Ceratti, Davide R; Louis, Benjamin; Boudot, Mickael; Albouy, Pierre-Antoine; Boissière, Cédric; Grosso, David

2014-10-08

In this work, unique functional devices exhibiting controlled gradients of properties are fabricated by dip-coating process in acceleration mode. Through this new approach, thin films with "on-demand" thickness graded profiles at the submillimeter scale are prepared in an easy and versatile way, compatible for large-scale production. The technique is adapted to several relevant materials, including sol-gel dense and mesoporous metal oxides, block copolymers, metal-organic framework colloids, and commercial photoresists. In the first part of the Article, an investigation on the effect of the dip coating speed variation on the thickness profiles is reported together with the critical roles played by the evaporation rate and by the viscosity on the fluid draining-induced film formation. In the second part, dip-coating in acceleration mode is used to induce controlled variation of functionalities by playing on structural, chemical, or dimensional variations in nano- and microsystems. In order to demonstrate the full potentiality and versatility of the technique, original graded functional devices are made including optical interferometry mirrors with bidirectional gradients, one-dimensional photonic crystals with a stop-band gradient, graded microfluidic channels, and wetting gradient to induce droplet motion.

Impact of Functionally Graded Cylinders: Theory

NASA Technical Reports Server (NTRS)

Aboudi, Jacob; Pindera, Marek-Jerzy; Arnold, S. M. (Technical Monitor)

2001-01-01

This final report summarizes the work funded under the Grant NAG3-2411 during the 04/05/2000-04/04/2001 period. The objective of this one-year project was to generalize the theoretical framework of the two-dimensional higher-order theory for the analysis of cylindrical functionally graded materials/structural components employed in advanced aircraft engines developed under past NASA Glenn funding. The completed generalization significantly broadens the theory's range of applicability through the incorporation of dynamic impact loading capability into its framework. Thus, it makes possible the assessment of the effect of damage due to fuel impurities, or the presence of submicron-level debris, on the life of functionally graded structural components. Applications involving advanced turbine blades and structural components for the reusable-launch vehicle (RLV) currently under development will benefit from the completed work. The theory's predictive capability is demonstrated through a numerical simulation of a one-dimensional wave propagation set up by an impulse load in a layered half-plane. Full benefit of the completed generalization of the higher-order theory described in this report will be realized upon the development of a related computer code.

Teacher's Resource Handbook for Asian Studies: An Annotated Bibliography of Curriculum Materials, Preschool through Grade Twelve.

ERIC Educational Resources Information Center

Hawkins, John N.

This handbook is an annotated bibliography of 1,586 instructional materials for teaching about Asia. Existing materials are identified that can be used by precollegiate teachers of all subject areas. The handbook is arranged by grade levels--preschool to grade 3, grades 4-6, junior high, senior high, and ungraded. Within each section, materials…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Meimei; Wang, Leyun; Almer, Jonathan D.

Deformation processes in Grade 91 (Fe–9%Cr–1%Mo–V,Nb) and Grade 92 (Fe–9%Cr–0.5%Mo–2%W–V,Nb) ferritic–martensitic steels were investigated at temperatures between 20 and 650 °C using high-energy synchrotron X-ray diffraction with in situ thermal–mechanical loading. The change of the dislocation density with strain was quantified by X-ray diffraction line profile analysis complemented by transmission electron microscopy measurements. The relationship between dislocation density and strain during uniform deformation was described by a dislocation model, and two critical materials parameters, namely dislocation mean free path and dynamic recovery coefficient, were determined as a function of temperature. Effects of alloy chemistry, thermal–mechanical treatment and temperature on themore » tensile deformation process in Grade 91 and Grade 92 steels can be well understood by the dislocation evolution behavior.« less

Vibration of functionally graded plate resting on viscoelastic elastic foundation subjected to moving loads

NASA Astrophysics Data System (ADS)

Duy Hien, Ta; Lam, Nguyen Ngoc

2018-04-01

The dynamics of plates subjected to a moving load must be considered by engineering mechanics and design structures. This paper deals with the dynamic responses of functionally graded (FG) rectangular plates resting on a viscoelastic foundation under moving loads. It is assumed that material properties of the plate vary continuously in the thickness direction according to the power-law. The governing equations are derived by using Hamilton’s principle, which considers the effect of the higher-order shear deformation in the plate. Transient responses of simply supported FG rectangular plates are employed by using state-space methods. Several examples are given for displacement and stresses in the plates with various structural parameters, and the effects of these parameters are discussed.

Math Academy: Can You See It in Nature? Explorations in Patterns & Functions. Book 2: Supplemental Math Materials for Grades 3-8

ERIC Educational Resources Information Center

Rimbey, Kimberly

2007-01-01

Created by teachers for teachers, the Math Academy tools and activities included in this booklet were designed to create hands-on activities and a fun learning environment for the teaching of mathematics to students. This booklet contains the "Math Academy--Can You See It in Nature? Explorations in Patterns & Functions," which a teacher can use to…

Research into material behaviour of the polymeric samples obtained after 3D-printing and subjected to compression test

NASA Astrophysics Data System (ADS)

Petrov, Mikhail A.; Kosatchyov, Nikolay V.; Petrov, Pavel A.

2016-10-01

The paper represents the results of the study concerning the investigation of the influence of the filling grade (material density) on the force characteristic during the uniaxial compression test of the cylindrical polymer probes produced by additive technology based on FDM. The authors have shown that increasing of the filling grate follows to the increase of the deformation forces. However, the dependency is not a linear function and characterized by soft-elastic model of material behaviour, which is typical for polymers partly crystallized structure.

Functionally graded bioactive coatings: From fabrication to testing

NASA Astrophysics Data System (ADS)

Foppiano, Silvia

Every year about half a million Americans undergo total joint replacement surgery of some kind. This number is expected to steadily increase in the future. About 20% of these patients will need a revision surgery because of implant failure, with a significant increase in health care cost. Current implant materials for load bearing applications must be strong enough to support the loads involved in daily activities, and bioinert, to limit reactivity in the body that may cause inflammatory and other adverse reactions. Metal alloys are typically used as materials for load bearing implants and rely on mechanical interlocking to achieve fixation which can be improved by using bone cements. To improve implant osteointegration, metal implants have been coated with a bone-like mineral: hydroxyapatite (HA). The plasma spray technique is commonly used to apply the HA coating. Such implants do not require the use of bone cement. Plasma sprayed HA coated implants are FDA approved and currently on the market, but their properties are not reproducible or reliable. Thus, coating delamination can occur. Our research group developed a novel family of bioactive glasses which were enameled onto titanium alloy using a functionally graded approach. We stratified the coating with different glass compositions to fulfill different functions. We coupled a first glass layer, with a good CTE match to the alloy, with a second layer of bioactive glass obtaining a functionally graded bioactive coating (FGC). In this thesis for the first time the cytocompatibility of novel bioactive glasses, and their functionally graded coatings on Ti6Al4V, was studied with an in vitro bone model (MC3T3-E1.4 mouse preosteblast cells). The novel bioactive glasses are cytocompatible and no compositional change is required. The fabrication process is reproducible, introduces a small (average 6 vol%) amount of crystallization, which does not significantly affect bioactivity in SBF as tested. The coatings are cytocompatible, but should be preconditioned in SBF prior to their use. Preconditioning stabilizes the coatings, eliminates possible contaminants introduced during processing and handling, and yields dissolution products capable of inducing specific gene expression (e.g. Runx-2). Future research will involve identification of such dissolution products as well as in vivo testing.

Application of Calcium Phosphate Materials in Dentistry

PubMed Central

Al-Sanabani, Jabr S.; Al-Sanabani, Fadhel A.

2013-01-01

Calcium phosphate materials are similar to bone in composition and in having bioactive and osteoconductive properties. Calcium phosphate materials in different forms, as cements, composites, and coatings, are used in many medical and dental applications. This paper reviews the applications of these materials in dentistry. It presents a brief history, dental applications, and methods for improving their mechanical properties. Notable research is highlighted regarding (1) application of calcium phosphate into various fields in dentistry; (2) improving mechanical properties of calcium phosphate; (3) biomimetic process and functionally graded materials. This paper deals with most common types of the calcium phosphate materials such as hydroxyapatite and tricalcium phosphate which are currently used in dental and medical fields. PMID:23878541

Naturally formed graded junction for organic light-emitting diodes

NASA Astrophysics Data System (ADS)

Shao, Yan; Yang, Yang

2003-09-01

In this letter, we report naturally-formed graded junctions (NFGJ) for organic light-emitting diodes (OLEDs). These junctions are fabricated using single thermal evaporation boat loaded with uniformly mixed charge transport and light-emitting materials. Upon heating, materials sublimate sequentially according to their vaporizing temperatures forming the graded junction. Two kinds of graded structures, sharp and shallow graded junctions, can be formed based on the thermal properties of the selected materials. The NFGJ OLEDs have shown excellent performance in both brightness and lifetime compared with heterojunction devices.

Tensiometer and method of determining soil moisture potential in below-grade earthen soil

DOEpatents

Hubbell, J.M.; Mattson, E.D.; Sisson, J.B.

1998-06-02

A tensiometer to in-situ determine below-grade soil moisture, potential of earthen soil includes, (a) an apparatus adapted for insertion into earthen soil below grade, the apparatus having a below-grade portion, and, comprising; (b) a porous material provided in the below-grade portion, the porous material at least in part defining a below-grade first fluid chamber; (c) a first fluid conduit extending outwardly of the first fluid chamber; (d) a first controllable isolation valve provided within the first fluid conduit, the first controllable isolation valve defining a second fluid chamber in fluid communication with the first fluid chamber through the first fluid conduit and the isolation valve, the first controllable isolation valve being received within the below-grade portion; and (e) a pressure transducer in fluid communication with the first fluid chamber, the pressure transducer being received within the below-grade portion. An alternate embodiment includes an apparatus adapted for insertion into earthen soil below grade, the apparatus having a below-grade portion, and including: (1) a porous material provided in the below-grade portion, the porous material at least in part defining a below-grade first fluid chamber; and (2) a pressure sensing apparatus in fluid communication with the first fluid chamber, the pressure sensing apparatus being entirely received within the below-grade portion. A method is also disclosed using the above and other apparatus. 6 figs.

Tensiometer and method of determining soil moisture potential in below-grade earthen soil

DOEpatents

Hubbell, Joel M.; Mattson, Earl D.; Sisson, James B.

1998-01-01

A tensiometer to in situ determine below-grade soil moisture, potential of earthen soil includes, a) an apparatus adapted for insertion into earthen soil below grade, the apparatus having a below-grade portion, and, comprising; b) a porous material provided in the below-grade portion, the porous material at least in part defining a below-grade first fluid chamber; c) a first fluid conduit extending outwardly of the first fluid chamber; d) a first controllable isolation valve provided within the first fluid conduit, the first controllable isolation valve defining a second fluid chamber in fluid communication with the first fluid chamber through the first fluid conduit and the isolation valve, the first controllable isolation valve being received within the below-grade portion; and e) a pressure transducer in fluid communication with the first fluid chamber, the pressure transducer being received within the below-grade portion. An alternate embodiment includes an apparatus adapted for insertion into earthen soil below grade, the apparatus having a below-grade portion, and including: i) a porous material provided in the below-grade portion, the porous material at least in part defining a below-grade first fluid chamber; and ii) a pressure sensing apparatus in fluid communication with the first fluid chamber, the pressure sensing apparatus being entirely received within the below-grade portion. A method is also disclosed using the above and other apparatus.

Nonlinear effective permittivity of field grading composite dielectrics

NASA Astrophysics Data System (ADS)

Yang, Xiao; Zhao, Xiaolei; Li, Qi; Hu, Jun; He, Jinliang

2018-02-01

Field grading composite dielectrics with good nonlinear electrical properties can function as smart materials for electrical field control in a high-voltage apparatus. Besides the well-documented nonlinear conducting behavior, the field-dependent effective permittivity of field grading composites were also reported; however, in-depth research on the mechanism and influencing factors of this nonlinear permittivity are absent. This paper theoretically discusses the origin of the nonlinear effective permittivity, and the mechanism is illustrated through the waveform analysis of the nonlinear response of ZnO microvaristor/silicone rubber composites under a pure AC field. The field-dependent effective permittivity and loss property of the ZnO composites are measured by a dielectric spectrometer in both DC and AC fields under different frequencies. Through comparison of measurement results and theoretical models, the influence of the filler concentration, frequency, and time domain characteristics of the applied field on the nonlinear permittivity of the field grading composites are well explained. This paper provides insight into the nonlinear permittivity of field grading composites, and will be helpful for further tuning the performance of field grading composites.

Deterministic Integration of Biological and Soft Materials onto 3D Microscale Cellular Frameworks

PubMed Central

McCracken, Joselle M.; Xu, Sheng; Badea, Adina; Jang, Kyung-In; Yan, Zheng; Wetzel, David J.; Nan, Kewang; Lin, Qing; Han, Mengdi; Anderson, Mikayla A.; Lee, Jung Woo; Wei, Zijun; Pharr, Matt; Wang, Renhan; Su, Jessica; Rubakhin, Stanislav S.; Sweedler, Jonathan V.

2018-01-01

Complex 3D organizations of materials represent ubiquitous structural motifs found in the most sophisticated forms of matter, the most notable of which are in life-sustaining hierarchical structures found in biology, but where simpler examples also exist as dense multilayered constructs in high-performance electronics. Each class of system evinces specific enabling forms of assembly to establish their functional organization at length scales not dissimilar to tissue-level constructs. This study describes materials and means of assembly that extend and join these disparate systems—schemes for the functional integration of soft and biological materials with synthetic 3D microscale, open frameworks that can leverage the most advanced forms of multilayer electronic technologies, including device-grade semiconductors such as monocrystalline silicon. Cellular migration behaviors, temporal dependencies of their growth, and contact guidance cues provided by the nonplanarity of these frameworks illustrate design criteria useful for their functional integration with living matter (e.g., NIH 3T3 fibroblast and primary rat dorsal root ganglion cell cultures). PMID:29552634

Love waves in functionally graded piezoelectric materials by stiffness matrix method.

PubMed

Ben Salah, Issam; Wali, Yassine; Ben Ghozlen, Mohamed Hédi

2011-04-01

A numerical matrix method relative to the propagation of ultrasonic guided waves in functionally graded piezoelectric heterostructure is given in order to make a comparative study with the respective performances of analytical methods proposed in literature. The preliminary obtained results show a good agreement, however numerical approach has the advantage of conceptual simplicity and flexibility brought about by the stiffness matrix method. The propagation behaviour of Love waves in a functionally graded piezoelectric material (FGPM) is investigated in this article. It involves a thin FGPM layer bonded perfectly to an elastic substrate. The inhomogeneous FGPM heterostructure has been stratified along the depth direction, hence each state can be considered as homogeneous and the ordinary differential equation method is applied. The obtained solutions are used to study the effect of an exponential gradient applied to physical properties. Such numerical approach allows applying different gradient variation for mechanical and electrical properties. For this case, the obtained results reveal opposite effects. The dispersive curves and phase velocities of the Love wave propagation in the layered piezoelectric film are obtained for electrical open and short cases on the free surface, respectively. The effect of gradient coefficients on coupled electromechanical factor, on the stress fields, the electrical potential and the mechanical displacement are discussed, respectively. Illustration is achieved on the well known heterostructure PZT-5H/SiO(2), the obtained results are especially useful in the design of high-performance acoustic surface devices and accurately prediction of the Love wave propagation behaviour. Copyright © 2010 Elsevier B.V. All rights reserved.

Probing the Natural World, Volume 1, Teachers Guide.

ERIC Educational Resources Information Center

Burkman, Ernest

This is the teaching guide for the first third of a coordinated science program for grades seven through nine. The materials have been prepared according to the following Intermediate Science Curriculum Study rationale: (1) science at the junior-high-school level should serve a general education function, and (2) both processes and concepts should…

Unit: Little Boxes, Inspection Set, National Trial Print.

ERIC Educational Resources Information Center

Australian Science Education Project, Toorak, Victoria.

The core portion of this unit prepared for students in grades seven and eight of Australian secondary schools aims to develop a greater awareness of the nature and function of housing. The historical development of housing styles and materials in Australia and elsewhere is studied from photographs, and simple investigations are suggested to…

Art. Program of Art Instruction in the Secondary School.

ERIC Educational Resources Information Center

Battle Creek Public Schools, MI.

GRADES OR AGES: Junior and senior high school. SUBJECT MATTER: Art. ORGANIZATION AND PHYSICAL APPEARANCE: The guide has four main sections: 1) "Aims of the Art Program"; 2) "Function of the Guide"; 3) "Course Descriptions"; and 4) "References, Source Materials, Aids." The course descriptions in section 3 are arranged in chart form with six…

Trash--Our Only Growing Resource. Environmental Ecological Education Project.

ERIC Educational Resources Information Center

Giebelhausen, Maribeth R.; And Others

With the increases in population and technology, non-biodegradable materials like plastic, glass, and aluminum and waste disposal have become very real problems in out society. This unit, designed for seventh-grade students, focuses on the problems of waste disposal and examines the function of recycling, the role of the consumer in determining…

A novel method for characterizing the impact response of functionally graded plates

NASA Astrophysics Data System (ADS)

Larson, Reid A.

Functionally graded material (FGM) plates are advanced composites with properties that vary continuously through the thickness of the plate. Metal-ceramic FGM plates have been proposed for use in thermal protection systems where a metal-rich interior surface of the plate gradually transitions to a ceramic-rich exterior surface of the plate. The ability of FGMs to resist impact loads must be demonstrated before using them in high-temperature environments in service. This dissertation presents a novel technique by which the impact response of FGM plates is characterized for low-velocity, low- to medium-energy impact loads. An experiment was designed where strain histories in FGM plates were collected during impact events. These strain histories were used to validate a finite element simulation of the test. A parameter estimation technique was developed to estimate local material properties in the anisotropic, non-homogenous FGM plates to optimize the finite element simulations. The optimized simulations captured the physics of the impact events. The method allows research & design engineers to make informed decisions necessary to implement FGM plates in aerospace platforms.

High-Fidelity Micromechanics Model Developed for the Response of Multiphase Materials

NASA Technical Reports Server (NTRS)

Aboudi, Jacob; Pindera, Marek-Jerzy; Arnold, Steven M.

2002-01-01

A new high-fidelity micromechanics model has been developed under funding from the NASA Glenn Research Center for predicting the response of multiphase materials with arbitrary periodic microstructures. The model's analytical framework is based on the homogenization technique, but the method of solution for the local displacement and stress fields borrows concepts previously employed in constructing the higher order theory for functionally graded materials. The resulting closed-form macroscopic and microscopic constitutive equations, valid for both uniaxial and multiaxial loading of periodic materials with elastic and inelastic constitutive phases, can be incorporated into a structural analysis computer code. Consequently, this model now provides an alternative, accurate method.

Multiscale design and multiobjective optimization of orthopedic hip implants with functionally graded cellular material.

PubMed

Arabnejad Khanoki, Sajad; Pasini, Damiano

2012-03-01

Revision surgeries of total hip arthroplasty are often caused by a deficient structural compatibility of the implant. Two main culprits, among others, are bone-implant interface instability and bone resorption. To address these issues, in this paper we propose a novel type of implant, which, in contrast to current hip replacement implants made of either a fully solid or a foam material, consists of a lattice microstructure with nonhomogeneous distribution of material properties. A methodology based on multiscale mechanics and design optimization is introduced to synthesize a graded cellular implant that can minimize concurrently bone resorption and implant interface failure. The procedure is applied to the design of a 2D left implanted femur with optimized gradients of relative density. To assess the manufacturability of the graded cellular microstructure, a proof-of-concept is fabricated by using rapid prototyping. The results from the analysis are used to compare the optimized cellular implant with a fully dense titanium implant and a homogeneous foam implant with a relative density of 50%. The bone resorption and the maximum value of interface stress of the cellular implant are found to be over 70% and 50% less than the titanium implant while being 53% and 65% less than the foam implant.

Dynamic mechanical thermal analysis of hypromellose 2910 free films.

PubMed

Cespi, Marco; Bonacucina, Giulia; Mencarelli, Giovanna; Casettari, Luca; Palmieri, Giovanni Filippo

2011-10-01

It is common practice to coat oral solid dosage forms with polymeric materials for controlled release purposes or for practical and aesthetic reasons. Good knowledge of thermo-mechanical film properties or their variation as a function of polymer grade, type and amount of additives or preparation method is of prime importance in developing solid dosage forms. This work focused on the dynamic mechanical thermal characteristics of free films of hypromellose 2910 (also known as HPMC), prepared using three grades of this polymer from two different manufacturers, in order to assess whether polymer chain length or origin affects the mechanical or thermo-mechanical properties of the final films. Hypromellose free films were obtained by casting their aqueous solutions prepared at a specific concentrations in order to obtain the same viscosity for each. The films were stored at room temperature until dried and then examined using a dynamic mechanical analyser. The results of the frequency scans showed no significant differences in the mechanical moduli E' and E″ of the different samples when analysed at room temperature; however, the grade of the polymer affected material transitions during the heating process. Glass transition temperature, apparent activation energy and fragility parameters depended on polymer chain length, while the material brand showed little impact on film performance. Copyright © 2011 Elsevier B.V. All rights reserved.

Preparation and characterization of Al{sub 2}O{sub 3}-Ti{sub 3}SiC{sub 2} composites and its functionally graded materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo Yongming; Li Shuqin; Chen Jian

2003-01-01

Alumina/titanium silicon carbide (Al{sub 2}O{sub 3}-Ti{sub 3}SiC{sub 2}) composites and its functionally graded materials (FGMs) were fabricated by a powder metallurgy processes and their microstructure and properties were investigated, respectively. The experimental results showed that the Vickers hardness of composites decreased with increasing Ti{sub 3}SiC{sub 2} content while the fracture toughness and strength exhibited the opposite trend. Minimum Vickers hardness (4 GPa), maximum strength (598 MPa) and maximum toughness (11.24 MPa m{sup 1/2}) were reached in the pure Ti{sub 3}SiC{sub 2} material. Strength and hardness of FGMs were evaluated. Observation using an scanning electron microscope (SEM) indicated that the presencemore » of Ti{sub 3}SiC{sub 2} of FGMs inhibited the growth of alumina grains through a pinning mechanism. The study shows that the combination of the layered Ti{sub 3}SiC{sub 2} structure and the fine alumina grains can result in a Al{sub 2}O{sub 3}-Ti{sub 3}SiC{sub 2} composites possessing a high toughness and low Vickers hardness without a sacrifice in the strength.« less

To reduce the maximum stress and the stress shielding effect around a dental implant-bone interface using radial functionally graded biomaterials.

PubMed

Asgharzadeh Shirazi, H; Ayatollahi, M R; Asnafi, A

2017-05-01

In a dental implant system, the value of stress and its distribution plays a pivotal role on the strength, durability and life of the implant-bone system. A typical implant consists of a Titanium core and a thin layer of biocompatible material such as the hydroxyapatite. This coating has a wide range of clinical applications in orthopedics and dentistry due to its biocompatibility and bioactivity characteristics. Low bonding strength and sudden variation of mechanical properties between the coating and the metallic layers are the main disadvantages of such common implants. To overcome these problems, a radial distributed functionally graded biomaterial (FGBM) was proposed in this paper and the effect of material property on the stress distribution around the dental implant-bone interface was studied. A three-dimensional finite element simulation was used to illustrate how the use of radial FGBM dental implant can reduce the maximum von Mises stress and, also the stress shielding effect in both the cortical and cancellous bones. The results, of course, give anybody an idea about optimized behaviors that can be achieved using such materials. The finite element solver was validated by familiar methods and the results were compared to previous works in the literature.

Direct laser metal deposition of WC/Co/Cr powder by means of the functionally graded materials strategy

NASA Astrophysics Data System (ADS)

Angelastro, A.; Campanelli, S. L.

2017-12-01

One of the many applications of direct laser metal deposition (DLMD) is the realization of multilayer thick coatings having particular mechanical characteristics, such as high hardness. The objective of this work was to obtain a thick, very hard and wear resistant coating, containing a high percentage of tungsten carbide (WC), on an AISI 304 stainless steel substrate. In order to achieve this result, a tungsten carbide-cobalt-chrome (WC/Co/Cr) powder was processed by the DLMD method. WC/Co/Cr is a composite widely used as a wear-resistant material for cutting tools, molds, coatings and other severe applications. Because of its high hardness, poor ductility and low thermal expansion coefficient, depositing this material directly on the stainless steel substrate is very difficult. In order to overcome this problem, the strategy of functionally graded materials (FGM) was used. Colmonoy 227-F nickel alloy was chosen for this purpose in order to generate a mixture with the WC/Co/Cr powder. Four different materials were deposited, layer by layer, by mixing Colmonoy 227-F with an increasing amount of WC/Co/Cr powders, until obtaining a thick surface coating with a maximum amount of WC of 77.4 wt%. For each powder mixture, a mathematical model was applied to calculate optimal values of translation speed and overlap percentages. A metallographic examination was performed in order to detect macro- and micro-structures of the different materials. Finally, Vickers micro-hardness was measured at various locations along the transverse section to appreciate the gradual increase of the FGM hardness, starting from the substrate and culminating at the top surface of the last deposited material.

Microassembly of Heterogeneous Materials using Transfer Printing and Thermal Processing

PubMed Central

Keum, Hohyun; Yang, Zining; Han, Kewen; Handler, Drew E.; Nguyen, Thong Nhu; Schutt-Aine, Jose; Bahl, Gaurav; Kim, Seok

2016-01-01

Enabling unique architectures and functionalities of microsystems for numerous applications in electronics, photonics and other areas often requires microassembly of separately prepared heterogeneous materials instead of monolithic microfabrication. However, microassembly of dissimilar materials while ensuring high structural integrity has been challenging in the context of deterministic transferring and joining of materials at the microscale where surface adhesion is far more dominant than body weight. Here we present an approach to assembling microsystems with microscale building blocks of four disparate classes of device-grade materials including semiconductors, metals, dielectrics, and polymers. This approach uniquely utilizes reversible adhesion-based transfer printing for material transferring and thermal processing for material joining at the microscale. The interfacial joining characteristics between materials assembled by this approach are systematically investigated upon different joining mechanisms using blister tests. The device level capabilities of this approach are further demonstrated through assembling and testing of a microtoroid resonator and a radio frequency (RF) microelectromechanical systems (MEMS) switch that involve optical and electrical functionalities with mechanical motion. This work opens up a unique route towards 3D heterogeneous material integration to fabricate microsystems. PMID:27427243

Consumption of pornographic materials in early adolescents in Hong Kong.

PubMed

Ma, Cecilia M S; Shek, Daniel T L

2013-06-01

The purpose of this study was to examine longitudinal changes in pornography consumption and related psychosocial correlates (ie, positive youth development qualities and family function) among Hong Kong early adolescents. In this study, adolescent consumption of pornographic materials was examined in 3 waves of longitudinal data. A total of 3,325 Secondary 1 students (Grade 7) from 28 schools participated in the study at Wave 1. The mean age of the participants was 12.6 years old (SD = .74). Results showed that the internet was the most common medium for consuming pornography materials. Boys consumed more pornographic materials than did girls. Findings showed that family functioning and positive youth development were negatively associated with consumption of pornographic materials over time. This study highlights the importance of developing adolescents' competencies and establishing an atmosphere that reduces the use of pornographic materials among adolescents. It sheds light on designing early prevention programs on pornography consumption for young people in Hong Kong. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

Functional gradients in the pericarp of the green coconut inspire asymmetric fibre-composites with improved impact strength, and preserved flexural and tensile properties.

PubMed

Graupner, Nina; Labonte, David; Humburg, Heide; Buzkan, Tayfun; Dörgens, Anna; Kelterer, Wiebke; Müssig, Jörg

2017-02-28

Here we investigate the mechanical properties and structural design of the pericarp of the green coconut (Cocos nucifera L.). The pericarp showed excellent impact characteristics, and mechanical tests of its individual components revealed gradients in stiffness, strength and elongation at break from the outer to the inner layer of the pericarp. In order to understand more about the potential effect of such gradients on 'bulk' material properties, we designed simple, graded, cellulose fibre-reinforced polylactide (PLA) composites by stacking layers reinforced with fibres of different mechanical properties. Tensile properties of the graded composites were largely determined by the 'weakest' fibre, irrespective of the fibre distribution. However, a graded design led to pronounced asymmetric bending and impact properties. Bio-inspired, asymmetrically graded composites showed a flexural strength and modulus comparable to that of the strongest reference samples, but the elongation at maximum load was dependent on the specimen orientation. The impact strength of the graded composites showed a similar orientation-dependence, and peak values exceeded the impact strength of a non-graded reference composite containing identical fibre fractions by up to a factor of three. In combination, our results show that an asymmetric, systematic variation of fibre properties can successfully combine desirable properties of different fibre types, suggesting new routes for the development of high-performance composites, and improving our understanding of the structure-function relationship of the coconut pericarp.

Readability of neurosurgery-related patient education materials provided by the American Association of Neurological Surgeons and the National Library of Medicine and National Institutes of Health.

PubMed

Schmitt, Paul J; Prestigiacomo, Charles J

2013-11-01

Most professional organizations now provide patient information material, and not all of this material is appropriate for the average American adult to comprehend. The National Institutes of Health (NIH) and the United States Department of Health and Human Services recommend that patient education materials be written at the sixth-grade level. Our aim was to assess the readability of neurosurgery-related patient education material and compare it with The American Medical Association, NIH, and United States Department of Health and Human Services recommendations. Materials provided by the American Association of Neurologic Surgeons (AANS) and the U.S. National Library of Medicine (NLM) and National Institutes of Health were assessed with the Flesch-Kincaid grade level and Flesch Reading Ease score with Microsoft Office Word software. None of the articles had Flesch-Kincaid grade levels at or below the sixth-grade level. All articles on the AANS Conditions and Treatments section were written at or above the ninth-grade level; three of the AANS Camera-Ready Fact Sheets and four of the NIH/NLM articles were written between the seventh- and eighth-grade levels. Current patient education material provided by the AANS is written well above the recommended level. Material from the NLM and NIH performed better, but was still above the recommended sixth-grade level. Education materials should contain information relevant to patients' conditions, be accurate in the information they present, and be written with the average patient in mind. Copyright © 2013 Elsevier Inc. All rights reserved.

PREFACE: 12th International Symposium on Multiscale, Multifunctional and Functionally Graded Materials (FGM 2012)

NASA Astrophysics Data System (ADS)

Zhou, Zhangjian; Li, Jingfeng; Zhang, Lianmeng; Ge, Changchun

2013-03-01

The 12th International Symposium on Multiscale, Multifunctional and Functionally Graded Materials (FGM-2012) was held in Beijing, China, from 22-36 October 2012. This was part of a series of conferences organized every two years endorsed by International Advisory Committee for FGM's, which serves as a forum for scientists, educators, engineers and young students interested in the development of functionally graded materials (FGM). The series continues from the previous international symposium on FGM held in Sendai, Japan (1990), San Francisco, USA (1992), Lausanne, Switzerland (1994), Tsukuba, Japan (1996), Dresden, Germany (1998), Estes Park, USA (2000), Beijing, China (2002), Leuven, Belgium (2004), Hawaii, USA (2006), Sendai, Japan (2008) and Guimaraes, Portugal (2010). Functionally graded materials are non-uniform materials which are designed with embodied continuous spatial variations in composition and microstructure for the specific purpose of adjusting their thermal, structural, mechanical, biological or functional response to specific application conditions. Such multi-phase materials cover a range of space and time scales, and are best understood by means of a comprehensive multiscale, multiphysics approach. These kinds of materials are presently in the forefront of materials research, receiving worldwide attention. They have a broad range of applications including for example, biomedical, biomechanical, automotive, aerospace, mechanical, civil, nuclear, and naval engineering. New applications are continuously being discovered and developed. The objective of the FGM-2012 intends to provide opportunities for exchanging ideas and discussing state-of-the-art theories, techniques and applications in the fields of multiscale, multifunctional and FGM, through invited lectures, oral and poster presentations. FGM-2012 was organized and hosted by University of Science and Technology Beijing, China, together with Tsing-hua University and Wuhan University of Technology, and was supported by National Natural Science Foundation of China. On behalf of the organizing committee of FGM-2012, I express my great appreciation to their support of the symposium. Nearly 100 scholars and students from Japan, Brazil, Germany, Russia, United States of America, Portugal, France, Switzerland, Turkey, Singapore, China, and so on, attended FGM-2012, and 57 of the presented papers were collected and selected for publication. The subjects of these papers cover simulation and characterization, advanced fabrication technology, novel application of FGM and layer materials. I cordially thank all of the authors and attendees for their support, and my appreciation is also given to the advisory committee, organizing committee, and the conference volunteers for their hard work. Professor Zhangjian Zhou Proceedings Editor Beijing, December 2012 Committees International Advisory Committee Professor Glaucio H Paulino, USA Professor Marek-Jerzy Pindera, USA Professor Jeong-Ho Kim, USA Professor Emer Fazil Erdogan, USA Professor Dr Monika Willert-Porada, Germany Professor Emer Wolfgang G J Bunk, Germany Professor Omer Van Der Biest, Belgium Professor Michael M Gasik, Finland Professor Evgeny Levashov, Russia Professor Lianmeng Zhang, China Professor Qingjie Zhang, China Professor Wei Pan, China Professor Chang-Chun Ge, China Professor Jing-Feng Li, China Professor Zhangjian Zhou, China Associate Professor Serkan Dag, Turkey Professor Fernando A Rochinha, Brazil Professor Emilio C N Silva, Brazil Professor Luis August Rocha, Portugal Dr Sasa Novak, Slovenia Dr Masayuki Niino, Japan Professor Akira Kawasaki, Japan Professor Ichiro Shiota, Japan Dr Akinaga Kumakawa, Japan Dr Yoshikazu Shinohara, Japan Professor Kiyotaka Matsuura, Japan Professor Yoshinari Miyamoto, Japan Professor Takashi Goto, Japan Professor Yoshimi Watanabe, Japan Professor Kazuhiro Hasezaki, Japan Professor Soshu Kirihara, Japan Professor Emer Toshio Hirai, Japan Mr Choji Endou, Japan Dr Seiichi Uemura, Japan Local Organizing Committee Professor Changchun Ge (Chairman) Professor Xuanhui Qu Professor Jingfeng Li Professor Wei Pan Professor Lianmeng Zhang; Professor Qingjie Zhang Professor Qiang Shen Professor Jianghong Gong Dr Xianhui Li Dr Min Xia

Functionally graded bio-ceramic reinforced PVA hydrogel composites for knee joint artificial cartilages

NASA Astrophysics Data System (ADS)

Kumar, G. C. Mohan

2018-04-01

Research progress in materials science for bio-based materials for cartilage repair or supportive to host tissue has become a fashionable, worldwide. Few efforts in biomedical engineering has attempted in the development of newer biomaterials successfully. Bio ceramics, a class of materials been used in particulate form as a reinforcement with polymers those ensure its biocompatibility. Every artificial biomedical system has to meet the minimum in Vitro requirements for successful application. Equally the biological behavior of normal and diseased tissues is also essential to understand the artificial systems to human body.

Pediatric intramedullary spinal cord lesions: Pathological spectrum and outcome of surgery

PubMed Central

Sahu, Rajni Kant; Das, Kuntal Kanti; Bhaisora, Kamlesh Singh; Singh, Amit Kumar; Mehrotra, Anant; Srivastava, Arun Kumar; Sahu, Rabi Narayan; Jaiswal, Awadhesh Kumar; Behari, Sanjay

2015-01-01

Background: Pediatric intramedullary spinal cord lesions are not only rare but also different from adults in a number of aspects. We aimed to study the incidence and the frequencies of various pediatric intramedullary mass lesions, their outcome to treatment and the factors determining their outcome of treatment. Materials and Methods: Thirty-one consecutive children (aged 1–18 years, mean 11.1 years, male: female = 1.8:1) with pathologically proven intramedullary spinal cord lesions treated at our center were studied. Clinico-radiological, histopathological, operative, and outcome data were reviewed retrospectively. The functional status was assessed using the modified McCormick grading system. Results: Gross total tumor excision was performed in 19 patients (61.3%), subtotal in 9 patients (29%), partial excision was performed in 2 (6.5%) patient, and only biopsy was performed in 1 patient (6.5%). There was one peroperative death, 2 patients died at follow-up. Complications included wound related complications (n = 4), transient deterioration in the motor power, and respiratory complication requiring a tracheostomy. Six patients showed recurrence at a mean follow-up of 16.4 months. Developmental tumors, high-grade ependymomas, and incompletely excised grade 2 ependymomas showed a tendency to recur. Conclusions: Children constituted nearly 1/5th (17.4%) of intramedullary spinal cord tumors. Astrocytomas and ependymomas taken together constituted the most common intramedullary spinal lesions in children; however, developmental tumors predominated in the first decade. Children usually presented in good functional grades preoperatively and maintained good grades after surgery. Functional outcome was dependent on the preoperative neurological status and histopathology of the lesions. PMID:26557160

Highway-rail grade crossing surface material performance.

DOT National Transportation Integrated Search

2014-04-01

Highway-Railroad grade crossings are an integral part of the transportation system, allowing the : two modes to operate in the same areas. Performance of the surface material at grade : crossings has been an ongoing issue. This study reviewed the lit...

Choosing the Adequate Level of Graded Readers--Preliminary Study

ERIC Educational Resources Information Center

Prtljaga, Jelena; Palinkaševic, Radmila; Brkic, Jovana

2015-01-01

Graded readers have been used as second language teaching material since the end of the Second World War. They are an important source of simplified material which provides comprehensible input on all levels. It is of crucial importance for a successful usage of graded readers in the classroom and in studies which focus on graded readers, that an…

Effects of Tube Processing on the Fatigue Life of Nitinol

NASA Astrophysics Data System (ADS)

Adler, Paul; Frei, Rudolf; Kimiecik, Michael; Briant, Paul; James, Brad; Liu, Chuan

2018-03-01

Nitinol tubes were manufactured from Standard Grade VIM-VAR ingots using Tube Manufacturing method "TM-1." Diamond-shaped samples were laser cut, shape set, then fatigued at 37 °C to 107 cycles. The 50, 5, and 1% probabilities of fracture were calculated as a function of number of cycles to fracture and compared with probabilities determined for fatigue data published by Robertson et al. (J Mech Behav Biomater 51:119-131, 2015). Robertson tested similar diamonds made from the same standard grade of Nitinol as in the current study, two other standard grades of Nitinol, and two high-purity grades of Nitinol expressly designed to improve fatigue life. Robertson's tubes were manufactured using Tube Manufacturing method "TM-2." Fatigue performance of TM-1 and TM-2 diamonds were compared: At 107 cycles, strain amplitudes corresponding to the three probabilities of fracture of the TM-1 diamonds were 2-3 times those of the TM-2 diamonds made from the same grade of Nitinol, and comparable to TM-2 diamonds made from the higher-purity materials. This difference is likely a result of the differences in tube manufacturing techniques and effects on resulting microstructures. Microstructural analyses of samples revealed a correlation between the median probability of fracture and median inclusion diameter that follows an inverse power-law function of the form y ≈ x -1.

Potential of direct metal deposition technology for manufacturing thick functionally graded coatings and parts for reactors components

NASA Astrophysics Data System (ADS)

Thivillon, L.; Bertrand, Ph.; Laget, B.; Smurov, I.

2009-03-01

Direct metal deposition (DMD) is an automated 3D deposition process arising from laser cladding technology with co-axial powder injection to refine or refurbish parts. Recently DMD has been extended to manufacture large-size near-net-shape components. When applied for manufacturing new parts (or their refinement), DMD can provide tailored thermal properties, high corrosion resistance, tailored tribology, multifunctional performance and cost savings due to smart material combinations. In repair (refurbishment) operations, DMD can be applied for parts with a wide variety of geometries and sizes. In contrast to the current tool repair techniques such as tungsten inert gas (TIG), metal inert gas (MIG) and plasma welding, laser cladding technology by DMD offers a well-controlled heat-treated zone due to the high energy density of the laser beam. In addition, this technology may be used for preventative maintenance and design changes/up-grading. One of the advantages of DMD is the possibility to build functionally graded coatings (from 1 mm thickness and higher) and 3D multi-material objects (for example, 100 mm-sized monolithic rectangular) in a single-step manufacturing cycle by using up to 4-channel powder feeder. Approved materials are: Fe (including stainless steel), Ni and Co alloys, (Cu,Ni 10%), WC compounds, TiC compounds. The developed coatings/parts are characterized by low porosity (<1%), fine microstructure, and their microhardness is close to the benchmark value of wrought alloys after thermal treatment (Co-based alloy Stellite, Inox 316L, stainless steel 17-4PH). The intended applications concern cooling elements with complex geometry, friction joints under high temperature and load, light-weight mechanical support structures, hermetic joints, tubes with complex geometry, and tailored inside and outside surface properties, etc.

Implications of Literacy Related to Comprehension of Environmental Health Materials

ERIC Educational Resources Information Center

Lindsey, Martha Ann

2010-01-01

Health literacy involves basic reading and numeracy, which allow a person to function as a health care consumer, by reading, understanding, evaluating and using information in health documents. For thirty years, the gap between the reading level of most of the public, eighth grade, and the reading level of most written health information, above…

Unit 1002: The Modes and Functions of Discourse.

ERIC Educational Resources Information Center

Minnesota Univ., Minneapolis. Center for Curriculum Development in English.

The purpose of this 10th-grade unit on language is to pose, for students, basic and tentative questions about the rhetorical uses of language. Examples are provided which designate the modes of language: Daniel Fogarty's story of rhetoric to show language which informs; materials from Northrop Frye to show language which inquires; a John F.…

Synthesis, Characterization And Modeling Of Functionally Graded Multifunctional Hybrid Composites For Extreme Environments

DTIC Science & Technology

2017-04-04

research thrust areas are designed to enable the development of reliable, damage tolerant, lightweight structures with excellent thermal management...46 2. RESEARCH THRUST AREA: MULTISCALE CHARACTERIZATION AND MODELING .................................... 56 2.1 DESIGN OF MATERIALS...The research thrust areas are designed to enable the development of reliable, damage tolerant, lightweight structures with excellent thermal

SCDC Spanish Curricula Units. Spanish SL, Unit 6, Grade 2, Teacher's Guide.

ERIC Educational Resources Information Center

Spanish Curricula Development Center, Miami Beach, FL.

Spanish for second graders is explored in the instructional and assessment activities of the unit six Spanish as a Second Language strand. The function of the strand is to help provide the English-dominant child with the structures and vocabulary needed for effective communication in a bilingual environment. Focus, objective, and materials for…

Differential quadrature method of nonlinear bending of functionally graded beam

NASA Astrophysics Data System (ADS)

Gangnian, Xu; Liansheng, Ma; Wang, Youzhi; Quan, Yuan; Weijie, You

2018-02-01

Using the third-order shear deflection beam theory (TBT), nonlinear bending of functionally graded (FG) beams composed with various amounts of ceramic and metal is analyzed utilizing the differential quadrature method (DQM). The properties of beam material are supposed to accord with the power law index along to thickness. First, according to the principle of stationary potential energy, the partial differential control formulae of the FG beams subjected to a distributed lateral force are derived. To obtain numerical results of the nonlinear bending, non-dimensional boundary conditions and control formulae are dispersed by applying the DQM. To verify the present solution, several examples are analyzed for nonlinear bending of homogeneous beams with various edges. A minute parametric research is in progress about the effect of the law index, transverse shear deformation, distributed lateral force and boundary conditions.

Controlling Weapons-Grade Fissile Material

ERIC Educational Resources Information Center

Rotblat, J.

1977-01-01

Discusses the problems of controlling weapons-grade fissionable material. Projections of the growth of fission nuclear reactors indicates sufficient materials will be available to construct 300,000 atomic bombs each containing 10 kilograms of plutonium by 1990. (SL)

7 CFR 810.2004 - Grades and grade requirements for triticale.

Code of Federal Regulations, 2010 CFR

2010-01-01

... material Material other than wheat or rye (percent) Total 2 (percent) Shrunken and broken kernels (percent... than wheat or rye. 3 Defects include damaged kernels (total), foreign material (total) and shrunken and...

7 CFR 810.2004 - Grades and grade requirements for triticale.

Code of Federal Regulations, 2014 CFR

2014-01-01

... material Material other than wheat or rye (percent) Total 2 (percent) Shrunken and broken kernels (percent... than wheat or rye. 3 Defects include damaged kernels (total), foreign material (total) and shrunken and...

7 CFR 810.2004 - Grades and grade requirements for triticale.

Code of Federal Regulations, 2012 CFR

2012-01-01

... material Material other than wheat or rye (percent) Total 2 (percent) Shrunken and broken kernels (percent... than wheat or rye. 3 Defects include damaged kernels (total), foreign material (total) and shrunken and...

7 CFR 810.2004 - Grades and grade requirements for triticale.

Code of Federal Regulations, 2011 CFR

2011-01-01

... material Material other than wheat or rye (percent) Total 2 (percent) Shrunken and broken kernels (percent... than wheat or rye. 3 Defects include damaged kernels (total), foreign material (total) and shrunken and...

7 CFR 810.2004 - Grades and grade requirements for triticale.

Code of Federal Regulations, 2013 CFR

2013-01-01

... material Material other than wheat or rye (percent) Total 2 (percent) Shrunken and broken kernels (percent... than wheat or rye. 3 Defects include damaged kernels (total), foreign material (total) and shrunken and...

Construction of sequences of exact analytical solutions for heat diffusion in graded heterogeneous materials by the Darboux transformation method. Examples for half-space

NASA Astrophysics Data System (ADS)

Krapez, J.-C.

2016-09-01

The Darboux transformation is a differential transformation which, like other related methods (supersymmetry quantum mechanics-SUSYQM, factorization method) allows generating sequences of solvable potentials for the stationary 1D Schrodinger equation. It was recently shown that the heat equation in graded heterogeneous media, after a Liouville transformation, reduces to a pair of Schrödinger equations sharing the same potential function, one for the transformed temperature and one for the square root of effusivity. Repeated joint PROperty and Field Darboux Transformations (PROFIDT method) then yield two sequences of solutions: one of new solvable effusivity profiles and one of the corresponding temperature fields. In this paper we present and discuss the outcome in the case of a graded half-space domain. The interest in this methodology is that it provides closed-form solutions based on elementary functions. They are thus easily amenable to an implementation in an inversion process aimed, for example, at retrieving a subsurface effusivity profile from a modulated or transient surface temperature measurement (photothermal characterization).

Agricultural produce grading and sorting system using color CCD and new color identification algorithm

NASA Astrophysics Data System (ADS)

Wang, Dongsheng; Zou, Jizuo; Yang, Yunping; Dong, Jianhua; Zhang, Yuanxiang

1996-10-01

A high-speed automatic agricultural produce grading and sorting system using color CCD and new color identification algorithm has been developed. In a typical application, the system can sort almonds into tow output grades according to their color. Almonds ar rich in 18 kinds of amino acids and 13 kinds of micro minerals and vitamins and can be made into almond drink. In order to ensure the drink quality, almonds must be sorted carefully before being made into a drink. Using this system, almonds can be sorted into two grades: up to grade and below grade almonds or foreign materials. A color CCD inspects the almonds passing on a conveyor of rotating rollers, a color identification algorithm grades almonds and distinguishes foreign materials from almonds. Employing an elaborately designed mechanism, the below grade almonds and foreign materials can be removed effectively from the raw almonds. This system can be easily adapted for inspecting and sorting other kinds of agricultural produce such as peanuts, beans tomatoes and so on.

Readability of online patient education materials from the AAOS web site.

PubMed

Sabharwal, Sanjeev; Badarudeen, Sameer; Unes Kunju, Shebna

2008-05-01

One of the goals of the American Academy of Orthopaedic Surgeons (AAOS) is to disseminate patient education materials that suit the readability skills of the patient population. According to standard guidelines from healthcare organizations, the readability of patient education materials should be no higher than the sixth-grade level. We hypothesized the readability level of patient education materials available on the AAOS Web site would be higher than the recommended grade level, regardless when the material was available online. Readability scores of all articles from the AAOS Internet-based patient information Web site, "Your Orthopaedic Connection," were determined using the Flesch-Kincaid grade formula. The mean Flesch-Kincaid grade level of the 426 unique articles was 10.43. Only 10 (2%) of the articles had the recommended readability level of sixth grade or lower. The readability of the articles did not change with time. Our findings suggest the majority of the patient education materials available on the AAOS Web site had readability scores that may be too difficult for comprehension by a substantial portion of the patient population.

Readability of Online Patient Education Materials From the AAOS Web Site

PubMed Central

Badarudeen, Sameer; Unes Kunju, Shebna

2008-01-01

One of the goals of the American Academy of Orthopaedic Surgeons (AAOS) is to disseminate patient education materials that suit the readability skills of the patient population. According to standard guidelines from healthcare organizations, the readability of patient education materials should be no higher than the sixth-grade level. We hypothesized the readability level of patient education materials available on the AAOS Web site would be higher than the recommended grade level, regardless when the material was available online. Readability scores of all articles from the AAOS Internet-based patient information Web site, “Your Orthopaedic Connection,” were determined using the Flesch-Kincaid grade formula. The mean Flesch-Kincaid grade level of the 426 unique articles was 10.43. Only 10 (2%) of the articles had the recommended readability level of sixth grade or lower. The readability of the articles did not change with time. Our findings suggest the majority of the patient education materials available on the AAOS Web site had readability scores that may be too difficult for comprehension by a substantial portion of the patient population. PMID:18324452

Evaluation of material dispersion using a nanosecond optical pulse radiator.

PubMed

Horiguchi, M; Ohmori, Y; Miya, T

1979-07-01

To study the material dispersion effects on graded-index fibers, a method for measuring the material dispersion in optical glass fibers has been developed. Nanosecond pulses in the 0.5-1.7-microm region are generated by a nanosecond optical pulse radiator and grating monochromator. These pulses are injected into a GeO(2)-P(2)0(5)-doped silica graded-index fiber. Relative time delay changes between different wavelengths are used to determine material dispersion, core glass refractive index, material group index, and optimum profile parameter of the graded-index fiber. From the measured data, the optimum profile parameter on the GeO(2)-P(2)O(5)-doped silica graded-index fiber could be estimated to be 1.88 at 1.27 microm of the material dispersion free wavelength region and 1.82 at 1.55 microm of the lowest-loss wavelength region in silica-based optical fiber waveguides.

The Effects of Linear and Modified Linear Programed Materials on the Achievement of Slow Learners in Tenth Grade BSCS Special Materials Biology.

ERIC Educational Resources Information Center

Moody, John Charles

Assessed were the effects of linear and modified linear programed materials on the achievement of slow learners in tenth grade Biological Sciences Curriculum Study (BSCS) Special Materials biology. Two hundred and six students were randomly placed into four programed materials formats: linear programed materials, modified linear program with…

Exact solutions for postbuckling of a graded porous beam

NASA Astrophysics Data System (ADS)

Ma, L. S.; Ou, Z. Y.

2018-06-01

An exact, closed-form solution for the postbuckling responses of graded porous beams subjected to axially loading is obtained. It was assumed that the properties of the graded porous materials vary continuously through thickness of the beams, the equations governing the axial and transverse deformations are derived based on the classical beam theory and the physical neutral surface concept. The two equations are reduced to a single nonlinear fourth-order integral-differential equation governing the transverse deformations. The nonlinear equation is directly solved without any use of approximation and a closed-form solution for postbuckled deformation is obtained as a function of the applied load. The exact solutions explicitly describe the nonlinear equilibrium paths of the buckled beam and thus are able to provide insight into deformation problems. Based on the exact solutions obtained herein, the effects of various factors such as porosity distribution pattern, porosity coefficient and boundary conditions on postbuckling behavior of graded porous beams have been investigated.

Size-dependent axisymmetric vibration of functionally graded circular plates in bifurcation/limit point instability

NASA Astrophysics Data System (ADS)

Ashoori, A. R.; Vanini, S. A. Sadough; Salari, E.

2017-04-01

In the present paper, vibration behavior of size-dependent functionally graded (FG) circular microplates subjected to thermal loading are carried out in pre/post-buckling of bifurcation/limit-load instability for the first time. Two kinds of frequently used thermal loading, i.e., uniform temperature rise and heat conduction across the thickness direction are considered. Thermo-mechanical material properties of FG plate are supposed to vary smoothly and continuously throughout the thickness based on power law model. Modified couple stress theory is exploited to describe the size dependency of microplate. The nonlinear governing equations of motion and associated boundary conditions are extracted through generalized form of Hamilton's principle and von-Karman geometric nonlinearity for the vibration analysis of circular FG plates including size effects. Ritz finite element method is then employed to construct the matrix representation of governing equations which are solved by two different strategies including Newton-Raphson scheme and cylindrical arc-length method. Moreover, in the following a parametric study is accompanied to examine the effects of the several parameters such as material length scale parameter, temperature distributions, type of buckling, thickness to radius ratio, boundary conditions and power law index on the dimensionless frequency of post-buckled/snapped size-dependent FG plates in detail. It is found that the material length scale parameter and thermal loading have a significant effect on vibration characteristics of size-dependent circular FG plates.

Processing biobased polymers using plasticizers: Numerical simulations versus experiments

NASA Astrophysics Data System (ADS)

Desplentere, Frederik; Cardon, Ludwig; Six, Wim; Erkoç, Mustafa

2016-03-01

In polymer processing, the use of biobased products shows lots of possibilities. Considering biobased materials, biodegradability is in most cases the most important issue. Next to this, bio based materials aimed at durable applications, are gaining interest. Within this research, the influence of plasticizers on the processing of the bio based material is investigated. This work is done for an extrusion grade of PLA, Natureworks PLA 2003D. Extrusion through a slit die equipped with pressure sensors is used to compare the experimental pressure values to numerical simulation results. Additional experimental data (temperature and pressure data along the extrusion screw and die are recorded) is generated on a dr. Collin Lab extruder producing a 25mm diameter tube. All these experimental data is used to indicate the appropriate functioning of the numerical simulation tool Virtual Extrusion Laboratory 6.7 for the simulation of both the industrial available extrusion grade PLA and the compound in which 15% of plasticizer is added. Adding the applied plasticizer, resulted in a 40% lower pressure drop over the extrusion die. The combination of different experiments allowed to fit the numerical simulation results closely to the experimental values. Based on this experience, it is shown that numerical simulations also can be used for modified bio based materials if appropriate material and process data are taken into account.

Functionally Graded Materials by Laser Metal Deposition (PREPRINT)

DTIC Science & Technology

2010-03-01

composition of Fe-82 wt% V (powder-1) and Inconel - 625 (powder-2) powders are listed in Table 1. The substrate materials used for the experiment were cold...like laser power, travel speed and powder feed rate is yet to be determined to obtain a successful FGM. Inconel - 625 deposits showed macro-cracks...Composition (wt%) Powder-1: Fe-82 wt% V V (82), Al (0.68), Si (0.9), C (0.07), S (0.01), P (0.02), Fe (18) Powder-2: Inconel - 625 Ni (58), Cr (20-23

Dopantless Diodes for Efficient Mid/deep UV LEDs and Lasers - Topic 4.2 Optoelectronics

DTIC Science & Technology

2017-09-12

Week, Santa Barbara, CA, “Polarization hole engineering in deep- ultraviolet nanowire LEDs”, ATM Sarwar, Santino Carnevale, Thomas Kent, Brelon May...Electronic Materials Conference, Santa Barbara, California, “ Engineering the polarization hole doping of graded nanowire ultraviolet LEDs integrated on...Nanostructures for Optoelectronic and Magnetic Functionalities: Growth, Characterization and Engineering Publication Type: Thesis or Dissertation

Electro-mechanical vibration analysis of functionally graded piezoelectric porous plates in the translation state

NASA Astrophysics Data System (ADS)

Wang, Yan Qing

2018-02-01

To provide reference for aerospace structural design, electro-mechanical vibrations of functionally graded piezoelectric material (FGPM) plates carrying porosities in the translation state are investigated. A modified power law formulation is employed to depict the material properties of the plates in the thickness direction. Three terms of inertial forces are taken into account due to the translation of plates. The geometrical nonlinearity is considered by adopting the von Kármán non-linear relations. Using the d'Alembert's principle, the nonlinear governing equation of the out-of-plane motion of the plates is derived. The equation is further discretized to a system of ordinary differential equations using the Galerkin method, which are subsequently solved via the harmonic balance method. Then, the approximate analytical results are validated by utilizing the adaptive step-size fourth-order Runge-Kutta technique. Additionally, the stability of the steady state responses is examined by means of the perturbation technique. Linear and nonlinear vibration analyses are both carried out and results display some interesting dynamic phenomenon for translational porous FGPM plates. Parametric study shows that the vibration characteristics of the present inhomogeneous structure depend on several key physical parameters.

Vibration analysis of a rotating functionally graded tapered microbeam based on the modified couple stress theory by DQEM

NASA Astrophysics Data System (ADS)

Ghadiri, Majid; Shafiei, Navvab; Alireza Mousavi, S.

2016-09-01

Due to having difficulty in solving governing nonlinear differential equations of a non-uniform microbeam, a few numbers of authors have studied such fields. In the present study, for the first time, the size-dependent vibration behavior of a rotating functionally graded (FG) tapered microbeam based on the modified couple stress theory is investigated using differential quadrature element method (DQEM). It is assumed that physical and mechanical properties of the FG microbeam are varying along the thickness that will be defined as a power law equation. The governing equations are determined using Hamilton's principle, and DQEM is presented to obtain the results for cantilever and propped cantilever boundary conditions. The accuracy and validity of the results are shown in several numerical examples. In order to display the influence of size on the first two natural frequencies and consequently changing of some important microbeam parameters such as material length scale, rate of cross section, angular velocity and gradient index of the FG material, several diagrams and tables are represented. The results of this article can be used in designing and optimizing elastic and rotary-type micro-electro-mechanical systems like micro-motors and micro-robots including rotating parts.

Spinodal Decomposition in Functionally Graded Super Duplex Stainless Steel and Weld Metal

NASA Astrophysics Data System (ADS)

Hosseini, Vahid A.; Thuvander, Mattias; Wessman, Sten; Karlsson, Leif

2018-07-01

Low-temperature phase separations (T < 500 °C), resulting in changes in mechanical and corrosion properties, of super duplex stainless steel (SDSS) base and weld metals were investigated for short heat treatment times (0.5 to 600 minutes). A novel heat treatment technique, where a stationary arc produces a steady state temperature gradient for selected times, was employed to fabricate functionally graded materials. Three different initial material conditions including 2507 SDSS, remelted 2507 SDSS, and 2509 SDSS weld metal were investigated. Selective etching of ferrite significantly decreased in regions heat treated at 435 °C to 480 °C already after 3 minutes due to rapid phase separations. Atom probe tomography results revealed spinodal decomposition of ferrite and precipitation of Cu particles. Microhardness mapping showed that as-welded microstructure and/or higher Ni content accelerated decomposition. The arc heat treatment technique combined with microhardness mapping and electrolytical etching was found to be a successful approach to evaluate kinetics of low-temperature phase separations in SDSS, particularly at its earlier stages. A time-temperature transformation diagram was proposed showing the kinetics of 475 °C-embrittlement in 2507 SDSS.

Spinodal Decomposition in Functionally Graded Super Duplex Stainless Steel and Weld Metal

NASA Astrophysics Data System (ADS)

Hosseini, Vahid A.; Thuvander, Mattias; Wessman, Sten; Karlsson, Leif

2018-04-01

Low-temperature phase separations (T < 500 °C), resulting in changes in mechanical and corrosion properties, of super duplex stainless steel (SDSS) base and weld metals were investigated for short heat treatment times (0.5 to 600 minutes). A novel heat treatment technique, where a stationary arc produces a steady state temperature gradient for selected times, was employed to fabricate functionally graded materials. Three different initial material conditions including 2507 SDSS, remelted 2507 SDSS, and 2509 SDSS weld metal were investigated. Selective etching of ferrite significantly decreased in regions heat treated at 435 °C to 480 °C already after 3 minutes due to rapid phase separations. Atom probe tomography results revealed spinodal decomposition of ferrite and precipitation of Cu particles. Microhardness mapping showed that as-welded microstructure and/or higher Ni content accelerated decomposition. The arc heat treatment technique combined with microhardness mapping and electrolytical etching was found to be a successful approach to evaluate kinetics of low-temperature phase separations in SDSS, particularly at its earlier stages. A time-temperature transformation diagram was proposed showing the kinetics of 475 °C-embrittlement in 2507 SDSS.

Fabrication and mechanical properties of Al2O3/SiC/ZrO2 functionally graded material by electrophoretic deposition.

PubMed

Askari, E; Mehrali, M; Metselaar, I H S C; Kadri, N A; Rahman, Md M

2012-08-01

This study describes the synthesis of Al(2)O(3)/SiC/ZrO(2) functionally graded material (FGM) in bio-implants (artificial joints) by electrophoretic deposition (EPD). A suitable suspension that was based on 2-butanone was applied for the EPD of Al(2)O(3)/SiC/ZrO(2), and a pressureless sintering process was applied as a presintering. Hot isostatic pressing (HIP) was used to densify the deposit, with beneficial mechanical properties after 2 h at 1800 °C in Ar atmosphere. The maximum hardness in the outer layer (90 vol.% Al(2)O(3)+10 vol.% SiC) and maximum fracture toughness in the core layer (75 vol.% Al(2)O(3)+10 vol.% SiC + 15 vol.% ZrO(2)) composite were 20.8±0.3 GPa and 8±0.1 MPa m(1/2), respectively. The results, when compared with results from Al(2)O(3)/ZrO(2) FGM, showed that SiC increased the compressive stresses in the outer layers, while the inner layers were under a residual tensile stress. Copyright © 2012 Elsevier Ltd. All rights reserved.

Efficient Reformulation of HOTFGM: Heat Conduction with Variable Thermal Conductivity

NASA Technical Reports Server (NTRS)

Zhong, Yi; Pindera, Marek-Jerzy; Arnold, Steven M. (Technical Monitor)

2002-01-01

Functionally graded materials (FGMs) have become one of the major research topics in the mechanics of materials community during the past fifteen years. FGMs are heterogeneous materials, characterized by spatially variable microstructure, and thus spatially variable macroscopic properties, introduced to enhance material or structural performance. The spatially variable material properties make FGMs challenging to analyze. The review of the various techniques employed to analyze the thermodynamical response of FGMs reveals two distinct and fundamentally different computational strategies, called uncoupled macromechanical and coupled micromechanical approaches by some investigators. The uncoupled macromechanical approaches ignore the effect of microstructural gradation by employing specific spatial variations of material properties, which are either assumed or obtained by local homogenization, thereby resulting in erroneous results under certain circumstances. In contrast, the coupled approaches explicitly account for the micro-macrostructural interaction, albeit at a significantly higher computational cost. The higher-order theory for functionally graded materials (HOTFGM) developed by Aboudi et al. is representative of the coupled approach. However, despite its demonstrated utility in applications where micro-macrostructural coupling effects are important, the theory's full potential is yet to be realized because the original formulation of HOTFGM is computationally intensive. This, in turn, limits the size of problems that can be solved due to the large number of equations required to mimic realistic material microstructures. Therefore, a basis for an efficient reformulation of HOTFGM, referred to as user-friendly formulation, is developed herein, and subsequently employed in the construction of the efficient reformulation using the local/global conductivity matrix approach. In order to extend HOTFGM's range of applicability, spatially variable thermal conductivity capability at the local level is incorporated into the efficient reformulation. Analytical solutions to validate both the user-friendly and efficient reformulations am also developed. Volume discretization sensitivity and validation studies, as well as a practical application of the developed efficient reformulation are subsequently carried out. The presented results illustrate the accuracy and implementability of both the user-friendly formulation and the efficient reformulation of HOTFGM.

An Overview of Promising Grades of Tool Materials Based on the Analysis of their Physical-Mechanical Characteristics

NASA Astrophysics Data System (ADS)

Kudryashov, E. A.; Smirnov, I. M.; Grishin, D. V.; Khizhnyak, N. A.

2018-06-01

The work is aimed at selecting a promising grade of a tool material, whose physical-mechanical characteristics would allow using it for processing the surfaces of discontinuous parts in the presence of shock loads. An analysis of the physical-mechanical characteristics of most common tool materials is performed and the data on a possible provision of the metal-working processes with promising composite grades are presented.

The Analysis of Adhesively Bonded Advanced Composite Joints Using Joint Finite Elements

NASA Technical Reports Server (NTRS)

Stapleton, Scott E.; Waas, Anthony M.

2012-01-01

The design and sizing of adhesively bonded joints has always been a major bottleneck in the design of composite vehicles. Dense finite element (FE) meshes are required to capture the full behavior of a joint numerically, but these dense meshes are impractical in vehicle-scale models where a course mesh is more desirable to make quick assessments and comparisons of different joint geometries. Analytical models are often helpful in sizing, but difficulties arise in coupling these models with full-vehicle FE models. Therefore, a joint FE was created which can be used within structural FE models to make quick assessments of bonded composite joints. The shape functions of the joint FE were found by solving the governing equations for a structural model for a joint. By analytically determining the shape functions of the joint FE, the complex joint behavior can be captured with very few elements. This joint FE was modified and used to consider adhesives with functionally graded material properties to reduce the peel stress concentrations located near adherend discontinuities. Several practical concerns impede the actual use of such adhesives. These include increased manufacturing complications, alterations to the grading due to adhesive flow during manufacturing, and whether changing the loading conditions significantly impact the effectiveness of the grading. An analytical study is conducted to address these three concerns. Furthermore, proof-of-concept testing is conducted to show the potential advantages of functionally graded adhesives. In this study, grading is achieved by strategically placing glass beads within the adhesive layer at different densities along the joint. Furthermore, the capability to model non-linear adhesive constitutive behavior with large rotations was developed, and progressive failure of the adhesive was modeled by re-meshing the joint as the adhesive fails. Results predicted using the joint FE was compared with experimental results for various joint configurations, including double cantilever beam and single lap joints.

What Types of Students' Effort Are Rewarded with High Marks?

ERIC Educational Resources Information Center

Kelly, Sean

2008-01-01

This analysis of data from the Partnership for Literacy Study investigates the relationship among achievement, effort, and grades. Certainly, grades reward achievement, the mastery of material by students. Research has also suggested that grades are used to reward students for exerting effort to learn material, even if students fall short of…

What Specific Facets of Executive Function are Associated with Academic Functioning in Youth with Attention-Deficit/Hyperactivity Disorder?

PubMed Central

Langberg, Joshua M.; Dvorsky, Melissa R.; Evans, Steven W.

2013-01-01

The purpose of the study was to evaluate the relation between ratings of Executive Function (EF) and academic functioning in a sample of 94 middle-school-aged youth with Attention-Deficit/Hyperactivity Disorder (ADHD; Mage = 11.9; 78% male; 21% minority). This study builds on prior work by evaluating associations between multiple specific aspects of EF (e.g., working memory, inhibition, and planning and organization) as rated by both parents and teachers on the Behavior Rating Inventory of Executive Function (BRIEF), with multiple academic outcomes, including school grades and homework problems. Further, this study examined the relationship between EF and academic outcomes above and beyond ADHD symptoms and controlled for a number of potentially important covariates, including intelligence and achievement scores. The EF Planning and Organization subscale as rated by both parents and teachers predicted school grades above and beyond symptoms of ADHD and relevant covariates. Parent ratings of youth’s ability to transition effectively between tasks/situations (Shift subscale) also predicted school grades. Parent-rated symptoms of inattention, hyperactivity/impulsivity, and planning and organization abilities were significant in the final model predicting homework problems. In contrast, only symptoms of inattention and the Organization of Materials subscale from the BRIEF were significant in the teacher model predicting homework problems. Organization and planning abilities are highly important aspects academic functioning for middle-school-aged youth with ADHD. Implications of these findings for the measurement of EF, and organization and planning abilities in particular, are discussed along with potential implications for intervention. PMID:23640285

Vibration and bending behavior of functionally graded nanocomposite doubly-curved shallow shells reinforced by graphene nanoplatelets

NASA Astrophysics Data System (ADS)

Wang, Aiwen; Chen, Hongyan; Hao, Yuxin; Zhang, Wei

2018-06-01

Free vibration and static bending of functionally graded (FG) graphene nanoplatelet (GPL) reinforced composite doubly-curved shallow shells with three distinguished distributions are analyzed. Material properties with gradient variation in the thickness aspect are evaluated by the modified Halpin-Tsai model. Mathematical model of the simply supported doubly-curved shallow shells rests upon Hamilton Principle and a higher order shear deformation theory (HSDT). The free vibration frequencies and bending deflections are gained by taking into account Navier technique. The agreement between the obtained results and ANSYS as well as the prior results in the open literature verifies the accuracy of the theory in this article. Further, parametric studies are accomplished to highlight the significant influence of GPL distribution patterns and weight fraction, stratification number, dimensions of GPLs and shells on the mechanical behavior of the system.

Chebyshev collocation approach for vibration analysis of functionally graded porous beams based on third-order shear deformation theory

NASA Astrophysics Data System (ADS)

Wattanasakulpong, Nuttawit; Chaikittiratana, Arisara; Pornpeerakeat, Sacharuck

2018-06-01

In this paper, vibration analysis of functionally graded porous beams is carried out using the third-order shear deformation theory. The beams have uniform and non-uniform porosity distributions across their thickness and both ends are supported by rotational and translational springs. The material properties of the beams such as elastic moduli and mass density can be related to the porosity and mass coefficient utilizing the typical mechanical features of open-cell metal foams. The Chebyshev collocation method is applied to solve the governing equations derived from Hamilton's principle, which is used in order to obtain the accurate natural frequencies for the vibration problem of beams with various general and elastic boundary conditions. Based on the numerical experiments, it is revealed that the natural frequencies of the beams with asymmetric and non-uniform porosity distributions are higher than those of other beams with uniform and symmetric porosity distributions.

Health Literacy: Readability of ACC/AHA Online Patient Education Material.

PubMed

Kapoor, Karan; George, Praveen; Evans, Matthew C; Miller, Weldon J; Liu, Stanley S

To determine whether the online patient education material offered by the American College of Cardiology (ACC) and the American Heart Association (AHA) is written at a higher level than the 6th-7th grade level recommended by the National Institute of Health (NIH). Online patient education material from each website was subjected to reading grade level (RGL) analysis using the Readability Studio Professional Edition. One-sample t testing was used to compare the mean RGLs obtained from 8 formulas to the NIH-recommended 6.5 grade level and 8th grade national mean. In total, 372 articles from the ACC website and 82 from the AHA were studied. Mean (±SD) RGLs for the 454 articles were 9.6 ± 2.1, 11.2 ± 2.1, 11.9 ± 1.6, 10.8 ± 1.6, 9.7 ± 2.1, 10.8 ± 0.8, 10.5 ± 2.6, and 11.7 ± 3.5 according to the Flesch-Kincaid grade level (FKGL), Simple Measure of Gobbledygook (SMOG Index), Coleman-Liau Index (CLI), Gunning-Fog Index (GFI), New Dale-Chall reading level formula (NDC), FORCAST, Raygor Readability Estimate (RRE), and Fry Graph (Fry), respectively. All analyzed articles had significantly higher RGLs than both the NIH-recommended grade level of 6.5 and the national mean grade level of 8 (p < 0.00625). Patient education material provided on the ACC and AHA websites is written above the NIH-recommended 6.5 grade level and 8th grade national mean reading level. Additional studies are required to demonstrate whether lowering the RGL of this material improves outcomes among patients with cardiovascular disease. © 2017 S. Karger AG, Basel.

Aeroelastic Tailoring of the NASA Common Research Model via Novel Material and Structural Configurations

NASA Technical Reports Server (NTRS)

Jutte, Christine V.; Stanford, Bret K.; Wieseman, Carol D.; Moore, James B.

2014-01-01

This work explores the use of tow steered composite laminates, functionally graded metals (FGM), thickness distributions, and curvilinear rib/spar/stringer topologies for aeroelastic tailoring. Parameterized models of the Common Research Model (CRM) wing box have been developed for passive aeroelastic tailoring trade studies. Metrics of interest include the wing weight, the onset of dynamic flutter, and the static aeroelastic stresses. Compared to a baseline structure, the lowest aggregate static wing stresses could be obtained with tow steered skins (47% improvement), and many of these designs could reduce weight as well (up to 14%). For these structures, the trade-off between flutter speed and weight is generally strong, although one case showed both a 100% flutter improvement and a 3.5% weight reduction. Material grading showed no benefit in the skins, but moderate flutter speed improvements (with no weight or stress increase) could be obtained by grading the spars (4.8%) or ribs (3.2%), where the best flutter results were obtained by grading both thickness and material. For the topology work, large weight reductions were obtained by removing an inner spar, and performance was maintained by shifting stringers forward and/or using curvilinear ribs: 5.6% weight reduction, a 13.9% improvement in flutter speed, but a 3.0% increase in stress levels. Flutter resistance was also maintained using straightrotated ribs although the design had a 4.2% lower flutter speed than the curved ribs of similar weight and stress levels were higher. These results will guide the development of a future design optimization scheme established to exploit and combine the individual attributes of these technologies.

Readability of patient education materials on the American Orthopaedic Society for Sports Medicine website.

PubMed

Eltorai, Adam E M; Han, Alex; Truntzer, Jeremy; Daniels, Alan H

2014-11-01

The recommended readability of patient education materials by the American Medical Association (AMA) and National Institutes of Health (NIH) should be no greater than a sixth-grade reading level. However, online resources may be too complex for some patients to understand, and poor health literacy predicts inferior health-related quality of life outcomes. This study evaluated whether the American Orthopaedic Society for Sports Medicine (AOSSM) website's patient education materials meet recommended readability guidelines for medical information. We hypothesized that the readability of these online materials would have a Flesch-Kincaid formula grade above the sixth grade. All 65 patient education entries of the AOSSM website were analyzed for grade level readability using the Flesch-Kincaid formula, a widely used and validated tool to evaluate the text reading level. The average (standard deviation) readability of all 65 articles was grade level 10.03 (1.44); 64 articles had a readability score above the sixth-grade level, which is the maximum level recommended by the AMA and NIH. Mean readability of the articles exceeded this level by 4.03 grade levels (95% CI, 3.7-4.4; P < 0.0001). We found post-hoc that only 7 articles had a readability score ≤ an eighth-grade level, the average reading level of US adults. Mean readability of the articles exceeded this level by 2.03 grade levels (95% CI, 1.7-2.4; P < 0.0001). The readability of online AOSSM patient education materials exceeds the readability level recommended by the AMA and NIH, and is above the average reading level of the majority of US adults. This online information may be of limited utility to most patients due to a lack of comprehension. Our study provides a clear example of the need to improve the readability of specific education material in order to maximize the efficacy of multimedia sources.

High Temperature Materials for Chemical Propulsion Applications

NASA Technical Reports Server (NTRS)

Elam, Sandra; Hickman, Robert; O'Dell, Scott

2007-01-01

Radiation or passively cooled thrust chambers are used for a variety of chemical propulsion functions including apogee insertion, reaction control for launch vehicles, and primary propulsion for planetary spacecraft. The performance of these thrust chambers is limited by the operating temperature of available materials. Improved oxidation resistance and increased operating temperatures can be achieved with the use of thermal barrier coatings such as zirconium oxide (ZrO2) and hafnium oxide (HfO2). However, previous attempts to include these materials showed cracking and spalling of the oxide layer due to poor bonding. Current research at NASA's Marshall Space Flight Center (MSFC) has generated unique, high temperature material options for in-space thruster designs that are capable of up to 2500 C operating temperatures. The research is focused on fabrication technologies to form low cost Iridium,qF_.henium (Ir/Re) components with a ceramic hot wall created as an integral, functionally graded material (FGM). The goal of this effort is to further de?celop proven technologies for embedding a protective ceramic coating within the Ir/Re liner to form a robust functional gradient material. Current work includes the fabrication and testing of subscale samples to evaluate tensile, creep, thermal cyclic/oxidation, and thermophysical material properties. Larger test articles have also being fabricated and hot-fire tested to demonstrate the materials in prototype thrusters at 1O0 lbf thrust levels.

Aeroelastic Tailoring of Transport Aircraft Wings: State-of-the-Art and Potential Enabling Technologies

NASA Technical Reports Server (NTRS)

Jutte, Christine; Stanford, Bret K.

2014-01-01

This paper provides a brief overview of the state-of-the-art for aeroelastic tailoring of subsonic transport aircraft and offers additional resources on related research efforts. Emphasis is placed on aircraft having straight or aft swept wings. The literature covers computational synthesis tools developed for aeroelastic tailoring and numerous design studies focused on discovering new methods for passive aeroelastic control. Several new structural and material technologies are presented as potential enablers of aeroelastic tailoring, including selectively reinforced materials, functionally graded materials, fiber tow steered composite laminates, and various nonconventional structural designs. In addition, smart materials and structures whose properties or configurations change in response to external stimuli are presented as potential active approaches to aeroelastic tailoring.

Optimal Experiment Design for Thermal Characterization of Functionally Graded Materials

NASA Technical Reports Server (NTRS)

Cole, Kevin D.

2003-01-01

The purpose of the project was to investigate methods to accurately verify that designed , materials meet thermal specifications. The project involved heat transfer calculations and optimization studies, and no laboratory experiments were performed. One part of the research involved study of materials in which conduction heat transfer predominates. Results include techniques to choose among several experimental designs, and protocols for determining the optimum experimental conditions for determination of thermal properties. Metal foam materials were also studied in which both conduction and radiation heat transfer are present. Results of this work include procedures to optimize the design of experiments to accurately measure both conductive and radiative thermal properties. Detailed results in the form of three journal papers have been appended to this report.

1974-75 NCTE Guide to Teaching Materials for English, Grades 7-12: An Annotated Listing of Textbooks and Related Materials for Secondary Schools Prepared by the NCTE Staff.

ERIC Educational Resources Information Center

National Council of Teachers of English, Urbana, IL.

This guide contains 550 annotations for English anthologies, textbooks, workbooks, multimedia packages, and other materials for grades 7-12. Works of literature, audiovisual materials, and professional publications are included only when integrally related to specific, listed instructional materials. Entries are grouped into the following subject…

Material and Thickness Grading for Aeroelastic Tailoring of the Common Research Model Wing Box

NASA Technical Reports Server (NTRS)

Stanford, Bret K.; Jutte, Christine V.

2014-01-01

This work quantifies the potential aeroelastic benefits of tailoring a full-scale wing box structure using tailored thickness distributions, material distributions, or both simultaneously. These tailoring schemes are considered for the wing skins, the spars, and the ribs. Material grading utilizes a spatially-continuous blend of two metals: Al and Al+SiC. Thicknesses and material fraction variables are specified at the 4 corners of the wing box, and a bilinear interpolation is used to compute these parameters for the interior of the planform. Pareto fronts detailing the conflict between static aeroelastic stresses and dynamic flutter boundaries are computed with a genetic algorithm. In some cases, a true material grading is found to be superior to a single-material structure.

Mathematics Through Science, Part II: Graphing, Equations and Linear Functions. Student Text. Revised Edition.

ERIC Educational Resources Information Center

Bolduc, Elroy J., Jr.; And Others

The purpose of this text is to teach learning and understanding of mathematics at grades seven through nine through the use of science experiments. Previous knowledge of science on the part of students or teachers is not necessary. The text is designed to be usable with any mathematics textbook in common use. The material can be covered in four…

Junior High Basals: Effective Hi/Lo Materials for Remedial High School Readers.

ERIC Educational Resources Information Center

Alvermann, Donna E.

1981-01-01

Discusses the results of an analysis of the appropriateness of eighth-grade basal reading materials for remedial instruction of ninth- and tenth-grade students who read two to three years below grade level. Readability, interest appeal, and representation of content areas are considered. Three data tables and a 14-item reference list are included.…

Suggestions for Teaching Mathematics Using Laboratory Approaches Grades 1-6. 4. Measurement. Experimental Edition.

ERIC Educational Resources Information Center

New York State Education Dept., Albany. Bureau of Elementary Curriculum Development.

This guide describes activities and materials which can be used in a mathematics laboratory approach to a basic mathematics program for grades 1-6. One-hundred thirteen activities pertaining to measurement concepts are described in terms of purpose, suggested grade levels, materials needed, and procedures. Some specific concepts include: linear…

Graded porous inorganic materials derived from self-assembled block copolymer templates.

PubMed

Gu, Yibei; Werner, Jörg G; Dorin, Rachel M; Robbins, Spencer W; Wiesner, Ulrich

2015-03-19

Graded porous inorganic materials directed by macromolecular self-assembly are expected to offer unique structural platforms relative to conventional porous inorganic materials. Their preparation to date remains a challenge, however, based on the sparsity of viable synthetic self-assembly pathways to control structural asymmetry. Here we demonstrate the fabrication of graded porous carbon, metal, and metal oxide film structures from self-assembled block copolymer templates by using various backfilling techniques in combination with thermal treatments for template removal and chemical transformations. The asymmetric inorganic structures display mesopores in the film top layers and a gradual pore size increase along the film normal in the macroporous sponge-like support structure. Substructure walls between macropores are themselves mesoporous, constituting a structural hierarchy in addition to the pore gradation. Final graded structures can be tailored by tuning casting conditions of self-assembled templates as well as the backfilling processes. We expect that these graded porous inorganic materials may find use in applications including separation, catalysis, biomedical implants, and energy conversion and storage.

Functionally Graded Multifunctional Hybrid Composites for Extreme Environments

DTIC Science & Technology

2010-02-01

Develop multifunctional FGHC with multiple layers: a ceramic thermal barrier layer, a graded ceramic /metal composite (GCMeC) layer and a high...AFOSR-MURI Functionally Graded Hybrid Composites Actively Cooled PMC White (UIUC) FGHC Fabrication Team Graded Ceramic Metal Composites (GCMeC...Composites Fabrication and Characterization of Bulk Ceramic MAX Phase and MAX–Metal Composites AFOSR-MURI Functionally Graded Hybrid Composites Mn

State of the art review on design and manufacture of hybrid biomedical materials: Hip and knee prostheses.

PubMed

Bahraminasab, Marjan; Farahmand, Farzam

2017-09-01

The trend in biomaterials development has now headed for tailoring the properties and making hybrid materials to achieve the optimal performance metrics in a product. Modern manufacturing processes along with advanced computational techniques enable systematical fabrication of new biomaterials by design strategy. Functionally graded materials as a recent group of hybrid materials have found numerous applications in biomedical area, particularly for making orthopedic prostheses. This article, therefore, seeks to address the following research questions: (RQ1) What is the desired structure of orthopedic hybrid materials? (RQ2) What is the contribution of the literature in the development of hybrid materials in the field of orthopedic research? (RQ3) Which type of manufacturing approaches is prevalently used to build these materials for knee and hip implants? (RQ4) Is there any inadequacy in the methods applied?

Grading of Student's Attainment: Purposes and Functions.

ERIC Educational Resources Information Center

Lysne, Anders

1984-01-01

Traces the history of grading and discusses the complex problem of evaluation and grading of student achievement. Reviews the various reference measures and notes the type of functions grades are supposed to serve. Cites seven alternatives to traditional grading. Concludes that "grades are the tail that wags the dog." (BRR)

Readability evaluation of Internet-based patient education materials related to the anesthesiology field.

PubMed

De Oliveira, Gildasio S; Jung, Michael; Mccaffery, Kirsten J; McCarthy, Robert J; Wolf, Michael S

2015-08-01

The main objective of the current investigation was to assess the readability of Internet-based patient education materials related to the field of anesthesiology. We hypothesized that the majority of patient education materials would not be written according to current recommended readability grade level. Online patient education materials describing procedures, risks, and management of anesthesia-related topics were identified using the search engine Google (available at www.google.com) using the terms anesthesia, anesthesiology, anesthesia risks, and anesthesia care. Cross-sectional evaluation. None. Assessments of content readability were performed using validated instruments (Flesch-Kincaid Grade Formulae, the Gunning Frequency of Gobbledygook, the New Dale-Chall Test, the Fry graph, and the Flesch Reading Ease score). Ninety-six Web sites containing Internet patient education materials (IPEMs) were evaluated. The median (interquartile range) readability grade level for all evaluated IPEMs was 13.5 (12.0-14.6). All the evaluated documents were classified at a greater readability level than the current recommended readability grade, P < .001. Readability grades were not significantly different among different IPEM sources. Assessment by the Flesch Reading Ease test classified all but 4 IPEMs as at least fairly difficult to read. Internet-based patient education materials related to the field of anesthesiology are currently written far above the recommended readability grade level. High complexity of written education materials likely limits access of information to millions of American patients. Redesign of online content of Web sites that provide patient education material regarding anesthesia could be an important step in improving access to information for patients with poor health literacy. Copyright © 2015 Elsevier Inc. All rights reserved.

Readability of Online Materials for Rhinoplasty.

PubMed

Santos, Pauline Joy F; Daar, David A; Paydar, Keyianoosh Z; Wirth, Garrett A

2018-01-01

Rhinoplasty is a popular aesthetic and reconstructive surgical procedure. However, little is known about the content and readability of online materials for patient education. The recommended grade level for educational materials is 7th to 8th grade according to the National Institutes of Health (NIH). This study aims to assess the readability of online patient resources for rhinoplasty. The largest public search engine, Google, was queried using the term "rhinoplasty" on February 26, 2016. Location filters were disabled and sponsored results excluded to avoid any inadvertent search bias. The 10 most popular websites were identified and all relevant, patient-directed information within one click from the original site was downloaded and saved as plain text. Readability was analyzed using five established analyses (Readability-score.com, Added Bytes, Ltd., Sussex, UK). Analysis of ten websites demonstrates an average grade level of at least 12 th grade. No material was at the recommended 7 th to 8 th grade reading level (Flesch-Kincaid, 11.1; Gunning-Fog, 14.1; Coleman-Liau, 14.5; SMOG 10.4; Automated Readability, 10.7; Average Grade Level, 12.2). Overall Flesch-Kincaid Reading Ease Index was 43.5, which is rated as "difficult." Online materials available for rhinoplasty exceed NIH-recommended reading levels, which may prevent appropriate decision-making in patients considering these types of surgery. Outcomes of this study identify that Plastic Surgeons should be cognizant of available online patient materials and make efforts to develop and provide more appropriate materials. Readability results can also contribute to marketing strategy and attracting a more widespread interest in the procedure.

Readability of Online Materials for Rhinoplasty

PubMed Central

Santos, Pauline Joy F; Daar, David A; Paydar, Keyianoosh Z; Wirth, Garrett A

2018-01-01

BACKGROUND Rhinoplasty is a popular aesthetic and reconstructive surgical procedure. However, little is known about the content and readability of online materials for patient education. The recommended grade level for educational materials is 7th to 8th grade according to the National Institutes of Health (NIH). This study aims to assess the readability of online patient resources for rhinoplasty. METHODS The largest public search engine, Google, was queried using the term “rhinoplasty” on February 26, 2016. Location filters were disabled and sponsored results excluded to avoid any inadvertent search bias. The 10 most popular websites were identified and all relevant, patient-directed information within one click from the original site was downloaded and saved as plain text. Readability was analyzed using five established analyses (Readability-score.com, Added Bytes, Ltd., Sussex, UK). RESULTS Analysis of ten websites demonstrates an average grade level of at least 12th grade. No material was at the recommended 7th to 8th grade reading level (Flesch-Kincaid, 11.1; Gunning-Fog, 14.1; Coleman-Liau, 14.5; SMOG 10.4; Automated Readability, 10.7; Average Grade Level, 12.2). Overall Flesch-Kincaid Reading Ease Index was 43.5, which is rated as “difficult.” CONCLUSION Online materials available for rhinoplasty exceed NIH-recommended reading levels, which may prevent appropriate decision-making in patients considering these types of surgery. Outcomes of this study identify that Plastic Surgeons should be cognizant of available online patient materials and make efforts to develop and provide more appropriate materials. Readability results can also contribute to marketing strategy and attracting a more widespread interest in the procedure. PMID:29651397

Materials characterization and fracture mechanics of a space grade dielectric silicone insulation

NASA Technical Reports Server (NTRS)

Abdel-Latif, A. I.; Tweedie, A. T.

1982-01-01

The present investigation is concerned with the DC 93-500 high voltage silicone insulation material employed to pot the gun and the collector end of a traveling wave tube (TWT) used on the Landsat D Satellite. The fracture mechanics behavior of the silicone resin was evaluated by measuring the slow crack velocity as a function of the opening mode of the stress intensity factor at +25 and -10 C, taking into account various uniaxial discrete strain values. It was found that the silicone resins slow crack growth is faster than that for a high voltage insulation polyurethane material at the same stress intensity factor value and room temperature.

Job Grading Standard for Materials Expediter WG-6705.

ERIC Educational Resources Information Center

Civil Service Commission, Washington, DC. Bureau of Policies and Standards.

The standard is used to grade nonsupervisory jobs involved in routing and expediting the movement of parts, end items, supplies, and materials within production and repair facilities to meet priority needs. The work requires knowledge of material characteristics, uses, condition, industrial production shop procedures, shop layout, and internal…

Adult Supratentorial Low-Grade Glioma: Long-Term Experience at a Single Institution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bauman, Glenn, E-mail: glenn.bauman@lhsc.on.c; Fisher, Barbara; Watling, Christopher

2009-12-01

Purpose: To report the long-term follow-up of a cohort of adult patients with supratentorial low-grade glioma treated at a single institution. Methods and Materials: A cohort of 145 adult patients treated at the London Regional Cancer Program between 1979 and 1995 was reviewed. Results: With a median follow-up of 105 months, the median progression-free survival was 61 months (95% confidence interval, 53-77), and the median overall survival was 118 months (95% confidence interval, 93-129). The 10- and 20-year progression-free and overall survival rate was 18% and 0% and 48% and 22%, respectively. Cox regression analysis confirmed the importance of age,more » histologic type, presence of seizures, Karnofsky performance status, and initial extent of surgery as prognostic variables for overall and cause-specific survival. Function among long-term survivors without tumor progression was good to excellent for most patients. Conclusion: Low-grade glioma is a chronic disease, with most patients dying of their disease. However, long-term survival with good function is possible. Survival is determined primarily by the disease factors with selection and timing of adjuvant treatments having less influence on outcome.« less

Dynamic Response of Functionally Graded Carbon Nanotube Reinforced Sandwich Plate

NASA Astrophysics Data System (ADS)

Mehar, Kulmani; Panda, Subrata Kumar

2018-03-01

In this article, the dynamic response of the carbon nanotube-reinforced functionally graded sandwich composite plate has been studied numerically with the help of finite element method. The face sheets of the sandwich composite plate are made of carbon nanotube- reinforced composite for two different grading patterns whereas the core phase is taken as isotropic material. The final properties of the structure are calculated using the rule of mixture. The geometrical model of the sandwich plate is developed and discretized suitably with the help of available shell element in ANSYS library. Subsequently, the corresponding numerical dynamic responses computed via batch input technique (parametric design language code in ANSYS) of ANSYS including Newmark’s integration scheme. The stability of the sandwich structural numerical model is established through the proper convergence study. Further, the reliability of the sandwich model is checked by comparison study between present and available results from references. As a final point, some numerical problems have been solved to examine the effect of different design constraints (carbon nanotube distribution pattern, core to face thickness ratio, volume fractions of the nanotube, length to thickness ratio, aspect ratio and constraints at edges) on the time-responses of sandwich plate.

Changes and Trends in the Pallet Industry: The Use of New Wood Materials

Treesearch

Robert J. Bush; Philip A. Araman

1998-01-01

Wood has dominated the pallet industry as its principal raw material since palletized material handling began. Pallet production and use grew dramatically after World War II and wood remained the material of choice. Throughout this period the pallet industry has been an important market for lower grades of hardwood lumber and cants. Today, the demand for pallet grade...

Material Development and Meeting Learner's Need

ERIC Educational Resources Information Center

Aydin, Abdullah

2013-01-01

In this study, the aim was to show that learners' needs can be met using simple and cheap materials that can be found everywhere in 9th to 11th grade Chemistry courses. To this end, materials were developed using simple everyday life materials for 9th to 11th grade Chemistry courses. In the research, the project method was employed. The study was…

Are patients comprehending? A critical assessment of online patient educational materials.

PubMed

Bui, Thanh-Lan; Silva-Hirschberg, Catalina; Torres, Josefina; Armstrong, April W

2018-05-01

The primary aim of this study was to evaluate the readability, understandability, suitability and actionability of online psoriasis patient educational materials. A secondary aim was to identify areas for improvement. We conducted an evaluation study to assess online psoriasis patient educational materials from the American Academy of Dermatology and National Psoriasis Foundation available in July 2017. We used two validated assessment tools specific to online healthcare materials. Outcomes were expressed as percentages, where higher percentages corresponded to higher quality materials. Overall, the educational materials had a mean understandability score (72.7%) that was understandable; a suitability score (58.8%) that was adequate; a reading grade level (10.5) that was not readable; and an actionability score (54.7%) that was not actionable. Areas of improvement include reading grade level, visual aids, word choice, specific steps for actions and cultural appropriateness. Online psoriasis patient educational materials are understandable and suitable, but they are written above the American Medical Association and National Institutes of Health's recommended 6th-8th grade reading level and are not actionable. Materials can benefit from decreasing reading grade level, including more visual elements, incorporating more actionable items and being culturally inclusive.

Readability of Patient Education Materials From the Web Sites of Orthopedic Implant Manufacturers.

PubMed

Yi, Meghan M; Yi, Paul H; Hussein, Khalil I; Cross, Michael B; Della Valle, Craig J

2017-12-01

Prior studies indicate that orthopedic patient education materials are written at a level that is too high for the average patient. The purpose of this study was to assess the readability of online patient education materials provided by orthopedic implant manufacturers. All patient education articles available in 2013 from the web sites of the 5 largest orthopedic implant manufacturers were identified. Each article was evaluated with the Flesch-Kincaid (FK) readability test. The number of articles with readability ≤ the eighth-grade level (average reading ability of US adults) and the sixth-grade level (recommended level for patient education materials) was determined. Mean readability levels of each company's articles were compared using analysis of variance (significance set at P < .05). A total of 581 articles were reviewed from the 5 largest implant manufacturers. The mean overall FK grade level was 10.9 (range, 3.8-16.1). Only 58 articles (10%) were written ≤ the eighth-grade level, and only 13 (2.2%) were ≤ the sixth-grade level. The mean FK grade level was significantly different among groups (Smith & Nephew = 12.0, Stryker = 11.6, Biomet = 11.3, DePuy = 10.6, Zimmer = 10.1; P < .0001). The majority of patient education materials from implant manufacturers are written at a level too high to be comprehended by the average patient. Future efforts should be made to improve the readability of orthopedic patient education materials. Copyright © 2017 Elsevier Inc. All rights reserved.

Readability assessment of the American Rhinologic Society patient education materials.

PubMed

Kasabwala, Khushabu; Misra, Poonam; Hansberry, David R; Agarwal, Nitin; Baredes, Soly; Setzen, Michael; Eloy, Jean Anderson

2013-04-01

The extensive amount of medical literature available on the Internet is frequently accessed by patients. To effectively contribute to healthcare decision-making, these online resources should be worded at a level that is readable by any patient seeking information. The American Medical Association and National Institutes of Health recommend the readability of patient information material should be between a 4th to 6th grade level. In this study, we evaluate the readability of online patient education information available from the American Rhinologic Society (ARS) website using 9 different assessment tools that analyze the materials for reading ease and grade level of the target audience. Online patient education material from the ARS was downloaded in February 2012 and assessed for level of readability using the Flesch Reading Ease, Flesch-Kincaid Grade Level, Simple Measure of Gobbledygook (SMOG) Grading, Coleman-Liau Index, Gunning-Fog Index, FORCAST formula, Raygor Readability Estimate, the Fry Graph, and the New Dale-Chall Readability Formula. Each article was pasted as plain text into a Microsoft® Word® document and each subsection was analyzed using the software package Readability Studio Professional Edition Version 2012.1. All healthcare education materials assessed were written between a 9th grade and graduate reading level and were considered "difficult" to read by the assessment scales. Online patient education materials on the ARS website are written above the recommended 6th grade level and may require revision to make them easily understood by a broader audience. © 2013 ARS-AAOA, LLC.

Comparative analysis of online patient education material pertaining to hepatitis and its complications.

PubMed

Gulati, Rishabh; Nawaz, Mohammad; Pyrsopoulos, Nikolaos T

2016-05-01

Approximately 50% of patients leave the doctor's office with a poor understanding of their diagnosis. Online patient education websites are becoming a major source of information for many of the patients. Here, we determine the reading grade level of online patient education materials on hepatitis B, hepatitis C, cirrhosis, and hepatocellular cancer and compare it with the National Institutes of Health-recommended reading grade level of sixth to seventh grade or under. A Google search was performed to retrieve patient reading materials. Text was modified to remove medical terms that were defined within the article. Documents were then divided into categories of introduction, risk factors, symptoms, diagnosis, treatment, and prevention. Each document was then analyzed using six validated readability tests to determine the grade level and complexity on the basis of the number of words, syllables, or number of uncommon words. Modified documents had a mean readability score of 10.23, although the recommended score is less than 7.0. Cirrhosis had the highest reading grade level, with a median of 11.3, whereas hepatitis B and hepatocellular carcinoma had the easiest readability, with a median of 9.5. Furthermore, treatment subsection was the most difficult, with a median score of 10.8. Patient reading materials reviewed in this study were written well above the recommended reading grade level. These findings suggest review of patient education materials in an effort to close the gap between the average reading level and the reading materials.

Readability of spine-related patient education materials from subspecialty organization and spine practitioner websites.

PubMed

Vives, Michael; Young, Lyle; Sabharwal, Sanjeev

2009-12-01

Analysis of spine-related websites available to the general public. To assess the readability of spine-related patient educational materials available on professional society and individual surgeon or practice based websites. The Internet has become a valuable source of patient education material. A significant percentage of patients, however, find this Internet based information confusing. Healthcare experts recommend that the readability of patient education material be less than the sixth grade level. The Flesch-Kincaid grade level is the most widely used method to evaluate the readability score of textual material, with lower scores suggesting easier readability. We conducted an Internet search of all patient education documents on the North American Spine Society (NASS), American Association of Neurological Surgeons (AANS), the American Academy of Orthopaedic Surgeons (AAOS), and a sample of 10 individual surgeon or practice based websites. The Flesch-Kincaid grade level of each article was calculated using widely available Microsoft Office Word software. The mean grade level of articles on the various professional society and individual/practice based websites were compared. A total of 121 articles from the various websites were available and analyzed. All 4 categories of websites had mean Flesch-Kincaid grade levels greater than 10. Only 3 articles (2.5%) were found to be at or below the sixth grade level, the recommended readability level for adult patients in the United States. There were no significant differences among the mean Flesch-Kincaid grade levels from the AAOS, NASS, AANS, and practice-based web-sites (P = 0.065, ANOVA). Our findings suggest that most of the Spine-related patient education materials on professional society and practice-based websites have readability scores that may be too high, making comprehension difficult for a substantial portion of the United States adult population.

Drifting Recovery Base Concept for GEO Derelict Object Capture

NASA Technical Reports Server (NTRS)

Bacon, John B.

2009-01-01

Over 250 objects hover within 6 m/sec of perfect geostationary orbit. Over half of these objects lie within 0.1 m/sec of the GEO velocity. Such items have 62% of the total velocity required to achieve Earth gravitational escape. A conceptual architecture is proposed to clean this orbit area of derelict objects while providing a demonstration mission for many facets of future asteroid mining operations. These near-GEO objects average nearly 2000kg each, consisting of (typically functioning) power systems, batteries, and large quantities of components and raw aerospace-grade refined materials. Such a demonstration collection system could capture, collect and remove all GEO derelict objects in an international effort to create a depot of components and of aerospace-grade raw materials--with a total mass greater than that of the International Space Station--as a space scrap depot ready for transfer to lunar or Mars orbit, using only two heavy-lift launches and 2-3 years of on-orbit operations.

Wrinkle surface instability of an inhomogeneous elastic block with graded stiffness

NASA Astrophysics Data System (ADS)

Yang, Shengyou; Chen, Yi-chao

2017-04-01

Surface instabilities have been studied extensively for both homogeneous materials and film/substrate structures but relatively less for materials with continuously varying properties. This paper studies wrinkle surface instability of a graded neo-Hookean block with exponentially varying modulus under plane strain by using the linear bifurcation analysis. We derive the first variation condition for minimizing the potential energy functional and solve the linearized equations of equilibrium to find the necessary conditions for surface instability. It is found that for a homogeneous block or an inhomogeneous block with increasing modulus from the surface, the critical stretch for surface instability is 0.544 (0.456 strain), which is independent of the geometry and the elastic modulus on the surface of the block. This critical stretch coincides with that reported by Biot (1963 Appl. Sci. Res. 12, 168-182. (doi:10.1007/BF03184638)) 53 years ago for the onset of wrinkle instabilities in a half-space of homogeneous neo-Hookean materials. On the other hand, for an inhomogeneous block with decreasing modulus from the surface, the critical stretch for surface instability ranges from 0.544 to 1 (0-0.456 strain), depending on the modulus gradient, and the length and height of the block. This sheds light on the effects of the material inhomogeneity and structural geometry on surface instability.

The Readability of AAOS Patient Education Materials: Evaluating the Progress Since 2008.

PubMed

Roberts, Heather; Zhang, Dafang; Dyer, George S M

2016-09-07

The Internet has become a major resource for patients; however, patient education materials are frequently written at relatively high levels of reading ability. The purpose of this study was to evaluate the readability of patient education materials on the American Academy of Orthopaedic Surgeons (AAOS) web site. Readability scores were calculated for all patient education articles on the AAOS web site using 5 algorithms: Flesch Reading Ease, Flesch-Kincaid Grade Level, SMOG (Simple Measure of Gobbledygook) Grade, Coleman-Liau Index, and Gunning-Fog Index. The mean readability scores were compared across the anatomic categories to which they pertained. Using a liberal measure of readability, the Flesch-Kincaid Grade Level, 3.9% of articles were written at or below the recommended sixth-grade reading level, and 84% of the articles were written above the eighth-grade reading level. Articles in the present study had a lower mean Flesch-Kincaid Grade Level than those available in 2008 (p < 0.00005). Articles categorized as "Hand & Wrist" or "Foot & Ankle" had significantly lower mean Flesch-Kincaid Grade Level scores than the mean for all categories (p < 0.0005). Regardless of the algorithm used, the mean readability levels of AAOS articles are higher than generally recommended. Although the mean Flesch-Kincaid Grade Level was lower in the present study than it was in 2008, a need remains to improve the readability of AAOS patient education articles. Ensuring that online patient education materials are written at an appropriate reading grade level would be expected to improve physician-patient communication. Copyright © 2016 by The Journal of Bone and Joint Surgery, Incorporated.

Active constrained layer damping of geometrically nonlinear vibrations of functionally graded plates using piezoelectric fiber-reinforced composites

NASA Astrophysics Data System (ADS)

Panda, Satyajit; Ray, M. C.

2008-04-01

In this paper, a geometrically nonlinear dynamic analysis has been presented for functionally graded (FG) plates integrated with a patch of active constrained layer damping (ACLD) treatment and subjected to a temperature field. The constraining layer of the ACLD treatment is considered to be made of the piezoelectric fiber-reinforced composite (PFRC) material. The temperature field is assumed to be spatially uniform over the substrate plate surfaces and varied through the thickness of the host FG plates. The temperature-dependent material properties of the FG substrate plates are assumed to be graded in the thickness direction of the plates according to a power-law distribution while the Poisson's ratio is assumed to be a constant over the domain of the plate. The constrained viscoelastic layer of the ACLD treatment is modeled using the Golla-Hughes-McTavish (GHM) method. Based on the first-order shear deformation theory, a three-dimensional finite element model has been developed to model the open-loop and closed-loop nonlinear dynamics of the overall FG substrate plates under the thermal environment. The analysis suggests the potential use of the ACLD treatment with its constraining layer made of the PFRC material for active control of geometrically nonlinear vibrations of FG plates in the absence or the presence of the temperature gradient across the thickness of the plates. It is found that the ACLD treatment is more effective in controlling the geometrically nonlinear vibrations of FG plates than in controlling their linear vibrations. The analysis also reveals that the ACLD patch is more effective for controlling the nonlinear vibrations of FG plates when it is attached to the softest surface of the FG plates than when it is bonded to the stiffest surface of the plates. The effect of piezoelectric fiber orientation in the active constraining PFRC layer on the damping characteristics of the overall FG plates is also discussed.

Adolescents born prematurely with isolated grade 2 haemorrhage in the early 1990s face increased risks of learning challenges.

PubMed

Vohr, Betty R; Allan, Walter; Katz, Karol H; Schneider, Karen; Tucker, Richard; Ment, Laura R

2014-10-01

To compare the impact of low-grade haemorrhage on neurocognitive function in 16-year-old adolescents born preterm, by grade of intraventricular haemorrhage, and term controls. We evaluated 338 preterm adolescents (birth weight 600-1250 g) for intelligence, executive function and memory tasks. Eleven had grade 3-4 haemorrhage, 44 had grade 2, 31 had grade 1, and 251 had no haemorrhage. Group comparisons were made with 102 term age-matched controls, and regression models used to identify the risk that low-grade haemorrhage posed for cognitive, executive function and memory deficits. Preterm adolescents with grade 2 haemorrhage had higher deficit rates of verbal intelligence, receptive vocabulary, phonemic fluency, cognitive flexibility and phonological fluency than preterm adolescents with grade 1 or no haemorrhage, compared with term controls. After excluding preterm adolescents with both grade 2 haemorrhage and cystic periventricular leukomalacia, those with isolated grade 2 haemorrhage remained at greater risk of cognitive and executive function deficits than term controls and of cognitive deficits than preterm adolescents with no haemorrhage. Our findings suggest that preterm adolescents born in the early 1990s with isolated grade 2 haemorrhage are at increased risk of learning challenges, including cognitive and executive function deficits. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Generalized Fractional Derivative Anisotropic Viscoelastic Characterization.

PubMed

Hilton, Harry H

2012-01-18

Isotropic linear and nonlinear fractional derivative constitutive relations are formulated and examined in terms of many parameter generalized Kelvin models and are analytically extended to cover general anisotropic homogeneous or non-homogeneous as well as functionally graded viscoelastic material behavior. Equivalent integral constitutive relations, which are computationally more powerful, are derived from fractional differential ones and the associated anisotropic temperature-moisture-degree-of-cure shift functions and reduced times are established. Approximate Fourier transform inversions for fractional derivative relations are formulated and their accuracy is evaluated. The efficacy of integer and fractional derivative constitutive relations is compared and the preferential use of either characterization in analyzing isotropic and anisotropic real materials must be examined on a case-by-case basis. Approximate protocols for curve fitting analytical fractional derivative results to experimental data are formulated and evaluated.

Modelling the influence of carbon content on material behavior during forging

NASA Astrophysics Data System (ADS)

Korpała, G.; Ullmann, M.; Graf, M.; Wester, H.; Bouguecha, A.; Awiszus, B.; Behrens, B.-A.; Kawalla, R.

2017-10-01

Nowadays the design of single process steps and even of whole process chains is realized by the use of numerical simulation, in particular finite element (FE) based methods. A detailed numerical simulation of hot forging processes requires realistic models, which consider the relevant material-specific parameters to characterize the material behavior, the surface phenomena, the dies as well as models for the machine kinematic. This data exists partial for several materials, but general information on steel groups depending on alloying elements are not available. In order to generate the scientific input data regarding to material modelling, it is necessary to take into account the mathematical functions for deformation behavior as well as recrystallization kinetic, which depends alloying elements, initial microstructure and reheating mode. Besides the material flow characterization, a detailed description of surface changes caused by oxide scale is gaining in importance, as these phenomena affect the material flow and the component quality. Experiments to investigate the influence of only one chemical element on the oxide scale kinetic and the inner structure at high temperatures are still not available. Most data concerning these characteristics is provided for the steel grade C45, so this steel will be used as basis for the tests. In order to identify the effect of the carbon content on the material and oxidation behavior, the steel grades C15 and C60 will be investigated. This paper gives first approaches with regard to the influence of the carbon content on the oxide scale kinetic and the flow stresses combined with the initial microstructure.

Bilingual/E.S.L. Materials Development, Grades 1-8, 1987. OREA Report.

ERIC Educational Resources Information Center

Berney, Tomi D.; Friedman, Grace Ibanez

New York City's program in Bilingual/E.S.L. Materials Development, Grade 1-8 was established to develop and/or update curricula and informational materials relevant to bilingual and English-as-a-Second-Language instruction. Curriculum development teams worked on independent activities. The project had 10 proposed curriculum initiatives, but the…

Materials and Techniques for Teaching the Esperanto Language in the Elementary Grades [and] 1996 Packet for Teachers.

ERIC Educational Resources Information Center

Jones, Kent

Materials presented here include a variety of resources for teachers of Esperanto: a brief guide to Esperanto teaching, including suggested teacher qualifications, a listing of instructional materials and resources, including serials, with details of publication, activities in preparation for teaching, grade-level class activities, notes on…

Tranpsort phenomena in solidification processing of functionally graded materials

NASA Astrophysics Data System (ADS)

Gao, Juwen

A combined numerical and experimental study of the transport phenomena during solidification processing of metal matrix composite functionally graded materials (FGMs) is conducted in this work. A multiphase transport model for the solidification of metal-matrix composite FGMs has been developed that accounts for macroscopic particle segregation due to liquid-particle flow and particle-solid interactions. An experimental study has also been conducted to gain physical insight as well as to validate the model. A novel method to in-situ measure the particle volume fraction using fiber optic probes is developed for transparent analogue solidification systems. The model is first applied to one-dimensional pure matrix FGM solidification under gravity or centrifugal field and is extensively validated against the experimental results. The mechanisms for the formation of particle concentration gradient are identified. Two-dimensional solidification of pure matrix FGM with convection is then studied using the model as well as experiments. The interaction among convection flow, solidification process and the particle transport is demonstrated. The results show the importance of convection in the particle concentration gradient formation. Then, simulations for alloy FGM solidification are carried out for unidirectional solidification as well as two-dimensional solidification with convection. The interplay among heat and species transport, convection and particle motion is investigated. Finally, future theoretical and experimental work is outlined.

Fabrication of Ti substrate grain dependent C/TiO2 composites through carbothermal treatment of anodic TiO2.

PubMed

Rüdiger, Celine; Favaro, Marco; Valero-Vidal, Carlos; Calvillo, Laura; Bozzolo, Nathalie; Jacomet, Suzanne; Hejny, Clivia; Gregoratti, Luca; Amati, Matteo; Agnoli, Stefano; Granozzi, Gaetano; Kunze-Liebhäuser, Julia

2016-04-07

Composite materials of titania and graphitic carbon, and their optimized synthesis are highly interesting for application in sustainable energy conversion and storage. We report on planar C/TiO2 composite films that are prepared on a polycrystalline titanium substrate by carbothermal treatment of compact anodic TiO2 with acetylene. This thin film material allows for the study of functional properties of C/TiO2 as a function of chemical composition and structure. The chemical and structural properties of the composite on top of individual Ti substrate grains are examined by scanning photoelectron microscopy and micro-Raman spectroscopy. Through comparison of these data with electron backscatter diffraction, it is found that the amount of generated carbon and the grade of anodic film crystallinity correlate with the crystallographic orientation of the Ti substrate grains. On top of Ti grains with ∼(0001) orientations the anodic TiO2 exhibits the highest grade of crystallinity, and the composite contains the highest fraction of graphitic carbon compared to Ti grains with other orientations. This indirect effect of the Ti substrate grain orientation yields new insights into the activity of TiO2 towards the decomposition of carbon precursors.

Vasomotor function in rat arteries after ex vivo and intragastric exposure to food-grade titanium dioxide and vegetable carbon particles.

PubMed

Jensen, Ditte Marie; Christophersen, Daniel Vest; Sheykhzade, Majid; Skovsted, Gry Freja; Lykkesfeldt, Jens; Münter, Rasmus; Roursgaard, Martin; Loft, Steffen; Møller, Peter

2018-02-26

Humans are continuously exposed to particles in the gastrointestinal tract. Exposure may occur directly through ingestion of particles via food or indirectly by removal of inhaled material from the airways by the mucociliary clearance system. We examined the effects of food-grade particle exposure on vasomotor function and systemic oxidative stress in an ex vivo study and intragastrically exposed rats. In an ex vivo study, aorta rings from naïve Sprague-Dawley rats were exposed for 30 min to food-grade TiO 2 (E171), benchmark TiO 2 (Aeroxide P25), food-grade vegetable carbon (E153) or benchmark carbon black (Printex 90). Subsequently, the vasomotor function was assessed in wire myographs. In an in vivo study, lean Zucker rats were exposed intragastrically once a week for 10 weeks to vehicle, E171 or E153. Doses were comparable to human daily intake. Vasomotor function in the coronary arteries and aorta was assessed using wire myographs. Tetrahydrobiopterin, ascorbate, malondialdehyde and asymmetric dimethylarginine were measured in blood as markers of oxidative stress and vascular function. Direct exposure of E171 to aorta rings ex vivo increased the acetylcholine-induced vasorelaxation and 5-hydroxytryptamine-induced vasocontraction. E153 only increased acetylcholine-induced vasorelaxation, and Printex 90 increased the 5-hydroxytryptamine-induced vasocontraction, whereas Aeroxide P25 did not affect the vasomotor function. In vivo exposure showed similar results as ex vivo exposure; increased acetylcholine-induced vasorelaxation in coronary artery segments of E153 and E171 exposed rats, whereas E171 exposure altered 5-hydroxytryptamine-induced vasocontraction in distal coronary artery segments. Plasma levels of markers of oxidative stress and vascular function showed no differences between groups. Gastrointestinal tract exposure to E171 and E153 was associated with modest albeit statistically significant alterations in the vasocontraction and vasorelaxation responses. Direct particle exposure to aorta rings elicited a similar type of response. The vasomotor responses were not related to biomarkers of systemic oxidative stress.

Combined Ventilation and Perfusion Imaging Correlates With the Dosimetric Parameters of Radiation Pneumonitis in Radiation Therapy Planning for Lung Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kimura, Tomoki, E-mail: tkkimura@hiroshima-u.ac.jp; Doi, Yoshiko; Nakashima, Takeo

2015-11-15

Purpose: The purpose of this study was to prospectively investigate clinical correlations between dosimetric parameters associated with radiation pneumonitis (RP) and functional lung imaging. Methods and Materials: Functional lung imaging was performed using four-dimensional computed tomography (4D-CT) for ventilation imaging, single-photon emission computed tomography (SPECT) for perfusion imaging, or both (V/Q-matched region). Using 4D-CT, ventilation imaging was derived from a low attenuation area according to CT numbers below different thresholds (vent-860 and -910). Perfusion imaging at the 10th, 30th, 50th, and 70th percentile perfusion levels (F10-F70) were defined as the top 10%, 30%, 50%, and 70% hyperperfused normal lung, respectively.more » All imaging data were incorporated into a 3D planning system to evaluate correlations between RP dosimetric parameters (where fV20 is the percentage of functional lung volume irradiated with >20 Gy, or fMLD, the mean dose administered to functional lung) and the percentage of functional lung volume. Radiation pneumonitis was evaluated using Common Terminology Criteria for Adverse Events version 4.0. Statistical significance was defined as a P value of <.05. Results: Sixty patients who underwent curative radiation therapy were enrolled (48 patients for non-small cell lung cancer, and 12 patients for small cell lung cancer). Grades 1, 2, and ≥3 RP were observed in 16, 44, and 6 patients, respectively. Significant correlations were observed between the percentage of functional lung volume and fV20 (r=0.4475 in vent-860 and 0.3508 in F30) or fMLD (r=0.4701 in vent-860 and 0.3128 in F30) in patients with grade ≥2 RP. F30∩vent-860 results exhibited stronger correlations with fV20 and fMLD in patients with grade ≥2 (r=0.5509 in fV20 and 0.5320 in fMLD) and grade ≥3 RP (r=0.8770 in fV20 and 0.8518 in fMLD). Conclusions: RP dosimetric parameters correlated significantly with functional lung imaging.« less

Continuing German in Grade Five: MLA Teacher's Guide. A Course of Study Including Methods, Materials, and Aids for Teaching German to Fifth-Grade Pupils.

ERIC Educational Resources Information Center

Memming, Agnes K.; And Others

This teacher's guide, for use in a fifth-grade German course, contains 12 units of instructional materials which concentrate on the development of basic audiolingual skills. Each of the units consists of conversational skits, dialogue adaptation, directed dialogue review, and classroom drills. Units include: (1) Das Aufstehen und das Fruhstuck,…

Solar Energy. 7th and 8th Grade Agriculture Science Curriculum. Teacher Materials.

ERIC Educational Resources Information Center

Southern Illinois Univ., Carbondale. Dept. of Agricultural Education and Mechanization.

This curriculum guide, the third in a set of six, contains teacher and student materials for a unit on solar energy prepared as part of a seventh- and eighth-grade agricultural science curriculum that is integrated with science instruction. The guide contains the state goals and sample learning objectives for each goal for students in grades 8-10…

Plutonium Finishing Plant (PFP) Final Safety Analysis Report (FSAR) [SEC 1 THRU 11

DOE Office of Scientific and Technical Information (OSTI.GOV)

ULLAH, M K

2001-02-26

The Plutonium Finishing Plant (PFP) is located on the US Department of Energy (DOE) Hanford Site in south central Washington State. The DOE Richland Operations (DOE-RL) Project Hanford Management Contract (PHMC) is with Fluor Hanford Inc. (FH). Westinghouse Safety Management Systems (WSMS) provides management support to the PFP facility. Since 1991, the mission of the PFP has changed from plutonium material processing to preparation for decontamination and decommissioning (D and D). The PFP is in transition between its previous mission and the proposed D and D mission. The objective of the transition is to place the facility into a stablemore » state for long-term storage of plutonium materials before final disposition of the facility. Accordingly, this update of the Final Safety Analysis Report (FSAR) reflects the current status of the buildings, equipment, and operations during this transition. The primary product of the PFP was plutonium metal in the form of 2.2-kg, cylindrical ingots called buttoms. Plutonium nitrate was one of several chemical compounds containing plutonium that were produced as an intermediate processing product. Plutonium recovery was performed at the Plutonium Reclamation Facility (PRF) and plutonium conversion (from a nitrate form to a metal form) was performed at the Remote Mechanical C (RMC) Line as the primary processes. Plutonium oxide was also produced at the Remote Mechanical A (RMA) Line. Plutonium processed at the PFP contained both weapons-grade and fuels-grade plutonium materials. The capability existed to process both weapons-grade and fuels-grade material through the PRF and only weapons-grade material through the RMC Line although fuels-grade material was processed through the line before 1984. Amounts of these materials exist in storage throughout the facility in various residual forms left from previous years of operations.« less

Mechanical characterization of hybrid and functionally-graded aluminum open-cell foams with nanocrystalline-copper coatings

NASA Astrophysics Data System (ADS)

Sun, Yi

Cellular/foam materials found in nature such as bone, wood, and bamboo are usually functionally graded by having a non-uniform density distribution and inhomogenous composition that optimizes their global mechanical performance. Inspired by such naturally engineered products, the current study was conducted towards the development of functionally graded hybrid metal foams (FGHMF) with electrodeposited (ED) nanocrystalline coatings. First, the deformation and failure mechanisms of aluminum/copper (Al/Cu) hybrid foams were investigated using finite element analyses at different scales. The micro-scale behavior was studied based on single ligament models discretized using continuum elements and the macro-scale behavior was investigated using beam-element based finite element models of representative unit volumes consisting of multiple foam cells. With a detailed constitutive material behavior and material failure considered for both the aluminum ligament and the nano-copper coating, the numerical models were able to capture the unique behavior of Al/Cu hybrid foams, such as the typically observed sudden load drop after yielding. The numerical models indicate that such load drop is caused by the fracture of foam ligaments initiated from the rupture of the ED nano-copper coating due to its low ductility. This failure mode jeopardizes the global energy absorption capacity of hybrid foams, especially when a thick coating is applied. With the purpose of enhancing the performance of Al/Cu hybrid foams, an annealing process, which increased the ductility of the nanocrystalline copper coating by causing recovery, recrystallination and grain growth, was introduced in the manufacturing of Al/Cu hybrid foams. Quasi-static experimental results indicate that when a proper amount of annealing is applied, the ductility of the ED copper can be effectively improved and the compressive and tensile behavior of Al/Cu hybrid foams can be significantly enhanced, including better energy absorption capacity. The behavior of Al/Cu hybrid foams under high-strain-rate condition was then investigated using experiments on a split Hopkinson pressure bar. It was found that the ED nano-copper coating can also effectively enhance the energy absorption capacities of aluminum open-cell foams under high strain rate. Similar to the quasi-static behavior, a large stress drop was observed in the compressive response of Al/Cu hybrid foams under high strain rate, which was accompanied by dramatic shattering of material. It is shown that a more ductile behavior and better energy absorption performance under high strain rate condition can be also obtained by introducing an annealing process. Finally, the manufacturing process of Al/Cu hybrid foams was customized to fabricate FGHMF systems with two dimensional property gradients. The performance of these FGHMFs at both quasi-static and dynamic conditions was evaluated. Under quasi-static condition, two flexural type loading conditions were considered, namely, a three point bending condition and a cantilever beam condition. The dynamic behavior of FGHMFs was investigated by conducting drop weight tower tests on a three point bending setup. It was found that the failure mechanism of hybrid metal foams can be modified and the mechanical properties, such as stiffness and strength, and energy absorption capacities of hybrid metal foams can be optimized under both quasi-static and dynamic conditions by introducing strategically designed coating patterns. The presented novel approach and findings in this study provide valuable information on the development of high performance hybrid and functionally-graded cellular materials.

Activation Inventories after Exposure to DD/DT Neutrons in Safety Analysis of Nuclear Fusion Installations.

PubMed

Stankunas, Gediminas; Cufar, Aljaz; Tidikas, Andrius; Batistoni, Paola

2017-11-23

Irradiations with 14 MeV fusion neutrons are planned at Joint European Torus (JET) in DT operations with the objective to validate the calculation of the activation of structural materials in functional materials expected in ITER and fusion plants. This study describes the activation and dose rate calculations performed for materials irradiated throughout the DT plasma operation during which the samples of real fusion materials are exposed to 14 MeV neutrons inside the JET vacuum vessel. Preparatory activities are in progress during the current DD operations with dosimetry foils to measure the local neutron fluence and spectrum at the sample irradiation position. The materials included those used in the manufacturing of the main in-vessel components, such as ITER-grade W, Be, CuCrZr, 316 L(N) and the functional materials used in diagnostics and heating systems. The neutron-induced activities and dose rates at shutdown were calculated by the FISPACT code, using the neutron fluxes and spectra that were provided by the preceding MCNP neutron transport calculations. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Acridine orange as a biosensitive photovoltaic material

NASA Astrophysics Data System (ADS)

Sharifi, Faranak; Bauld, Reg; Fanchini, Giovanni

2013-10-01

Acridine orange (AO), a biosensitive molecule that is customarily used for labeling nucleic acids including DNA and RNA, is here investigated as a cost effective, water soluble, and photoactive material for the fabrication of potentially biosensitive organic photovoltaics. The electronic energy levels of AO are determined using Kelvin Probe Force Microscopy (KPFM) and UV-Visible spectroscopy. The effect of anticrystallization agents, as well as low-temperature annealing, on the work function of AO is investigated: amorphous AO films are shown to possess a significantly higher work function than microcrystalline AO films and the work function also increases by annealing. Photo-induced processes in AO films are investigated by considering the changes of the KPFM signal under illumination. We demonstrate that acridine orange is able to photogenerate electron-hole pairs at rates comparable to the most commonly used solar-grade photovoltaic materials, including polythiophenes. In addition, the effect of the morphology of different types of AO thin films spun from different solvents is studied in bilayer photovoltaic devices fabricated from stacks of AO and phenyl-C61-butyric acid methyl ester thin films.

Material Structure of a Graded Refractive Index Lens in Decapod Squid

NASA Astrophysics Data System (ADS)

Cai, Jing; Heiney, Paul; Sweeney, Alison

2013-03-01

Underwater vision with a camera-type eye that is simultaneously acute and sensitive requires a spherical lens with a graded distribution of refractive index. Squids have this type of lens, and our previous work has shown that its optical properties are likely achieved with radially variable densities of a single protein with multiple isoforms. Here we measure the spatial organization of this novel protein material in concentric layers of the lens and use these data to suggest possible mechanisms of self-assembly of the proteins into a graded refractive index structure. First, we performed small angle x-ray scattering (SAXS) to study how the protein is spatially organized. Then, molecular dynamic simulation allowed us to correlate structure to the possible dynamics of the system in different regions of the lens. The combination of simulation and SAXS data in this system revealed the likely protein-protein interactions, resulting material structure and its relationship to the observed and variable optical properties of this graded index system. We believe insights into the material properties of the squid lens system will inform the invention of self-assembling graded index devices.

Photomultiplier window materials under electron irradiation - Fluorescence and phosphorescence

NASA Technical Reports Server (NTRS)

Viehmann, W.; Eubanks, A. G.; Pieper, G. F.; Bredekamp, J. H.

1975-01-01

The fluorescence and phosphorescence of photomultiplier window materials under electron irradiation have been investigated using a Sr-90/Y-90 beta emitter as the electron source. Spectral emission curves of UV-grade, optical-grade, and electron-irradiated samples of MgF2 and LiF, and of CaF2, BaF2, sapphire, fused silica, and UV-transmitting glasses were obtained over the 200-650-nm spectral range. Fluorescence yields were determined on these materials utilizing photomultiplier tubes with cesium telluride, bialkali, and trialkali (S-20) photocathodes, respectively. Optical-grade MgF2 and LiF, as well as electron-irradiated UV-grade samples of these two materials, show enhanced fluorescence due to color-center formation and associated emission bands in the blue and red wavelength regions. Large variations in fluorescence intensities were found in UV-grade sapphire samples of different origins, particularly in the red end of the spectrum, presumably due to various amounts of chromium-ion content. Phosphorescence decay with time is best described by a sum of exponential terms, with time constants ranging from a few minutes to several days.

MDA and AAEM informational brochures: can patients read them?

PubMed

Galloway, Gloria; Murphy, Peggy; Chesson, Andrew L; Martinez, Karen

2003-06-01

The purpose of this study was to assess patient literacy and the readability of patient education brochures from the American Academy of Electrodiagnostic Medicine and Muscular Dystrophy Association. Materials with the appropriate readability and suitability are more likely to provide instruction patients will understand. The readability of the brochure was assessed with Grammatik (Fry, 1977), the literacy of the participants with the Rapid Estimate of Adult Literacy (REALM) in Medicine test, and the suitability of the brochure was tested with the Suitability Assessment of Materials measure (Doak, Doak, & Root, 1993). The average REALM score for participation in this study correlated with a reading level of 7th-8th grade. All six brochures were found to be too difficult for many patients. Readability levels in four of the brochures were at 11th- or 12th-grade levels, one at 9th grade, and one at 10th grade. Materials with readability levels for 9th grade or higher should be rewritten to be understandable by most Americans, or supplemental instruction should be given. Readability and suitability assessments should be made to determine whether educational materials are appropriate for patients.

Assessment of Electron Beam Welding in Shipyard Construction,

DTIC Science & Technology

1985-12-01

electrical grade transformer oil which acts as a heat sink for the electrical components. The main high voltage power source converts the three phase I ne...tensile strength material in the range of 80 100 KSI (HY8O 10o0) *’*’ and 3) high strength low alloy material (A710 Gr. A with sulfur 0.0l0 maximum...Carbon Steel Structural Grade HSLA Steel Grade A710: 1) Carbon Steels (2-3") 2) Aluminum * - Grade E633: 3) Low Alloy HY 80, HY 100: -"Aluminum, Titanium

Dispersion relations of elastic waves in one-dimensional piezoelectric/piezomagnetic phononic crystal with functionally graded interlayers.

PubMed

Guo, Xiao; Wei, Peijun; Lan, Man; Li, Li

2016-08-01

The effects of functionally graded interlayers on dispersion relations of elastic waves in a one-dimensional piezoelectric/piezomagnetic phononic crystal are studied in this paper. First, the state transfer equation of the functionally graded interlayer is derived from the motion equation by the reduction of order (from second order to first order). The transfer matrix of the functionally graded interlayer is obtained by solving the state transfer equation with the spatial-varying coefficient. Based on the transfer matrixes of the piezoelectric slab, the piezomagnetic slab and the functionally graded interlayers, the total transfer matrix of a single cell is obtained. Further, the Bloch theorem is used to obtain the resultant dispersion equations of in-plane and anti-plane Bloch waves. The dispersion equations are solved numerically and the numerical results are shown graphically. Five kinds of profiles of functionally graded interlayers between a piezoelectric slab and a piezomagnetic slab are considered. It is shown that the functionally graded interlayers have evident influences on the dispersion curves and the band gaps. Copyright © 2016 Elsevier B.V. All rights reserved.

NCTE (National Council of Teachers of English) Guide to Teaching Materials for English, Grades 7-12; An Annotated Listing of Textbooks and Related Materials for Secondary Schools Prepared by the NCTE Staff. 1975-76 Supplement.

ERIC Educational Resources Information Center

National Council of Teachers of English, Urbana, IL.

This supplement to the "NCTE Guide to Teaching Materials for English, Grades 7-12" contains annotations for English anthologies, textbooks, workbooks, multimedia packages, and other materials for the junior high and high school levels. Works of literature, audiovisual materials, and professional publications are included when related to specific,…

Evaluation of internet-based patient education materials from internal medicine subspecialty organizations: will patients understand them?

PubMed

Hansberry, David R; Agarwal, Nitin; John, Elizabeth S; John, Ann M; Agarwal, Prateek; Reynolds, James C; Baker, Stephen R

2017-06-01

The majority of Americans use the Internet daily, if not more often, and many search online for health information to better understand a diagnosis they have been given or to research treatment options. The average American reads at an eighth-grade level. The purpose of this study is to evaluate the readability of online patient education materials on the websites of 14 professional organizations representing the major internal medicine subspecialties. We used ten well-established quantitative readability scales to assess written text from patient education materials published on the websites of the major professional organizations representing the following subspecialty groups: allergy and immunology, cardiology, endocrinology, gastroenterology, geriatrics, hematology, hospice and palliative care, infectious disease, nephrology, oncology, pulmonology and critical care, rheumatology, sleep medicine, and sports medicine. Collectively the 540 articles analyzed were written at an 11th-grade level (SD 1.4 grade levels). The sleep medicine and nephrology websites had the most readable materials, written at an academic grade level of 8.5 ± 1.5 and 9.0 ± 0.2, respectively. Material at the infectious disease site was written at the most difficult level, with average readability corresponding to grades 13.9 ± 0.3. None of the patient education materials we reviewed conformed to the American Medical Association (AMA) and the National Institutes of Health (NIH) guidelines requiring that patient education articles be written at a third- to seventh-grade reading level. If these online resources were rewritten, it is likely that more patients would derive benefit from reading them.

Nonlinear analysis of thermally and electrically actuated functionally graded material microbeam.

PubMed

Li, Yingli; Meguid, S A; Fu, Yiming; Xu, Daolin

2014-02-08

In this paper, we provide a unified and self-consistent treatment of a functionally graded material (FGM) microbeam with varying thermal conductivity subjected to non-uniform or uniform temperature field. Specifically, it is our objective to determine the effect of the microscopic size of the beam, the electrostatic gap, the temperature field and material property on the pull-in voltage of the microbeam under different boundary conditions. The non-uniform temperature field is obtained by integrating the steady-state heat conduction equation. The governing equations account for the microbeam size by introducing an internal material length-scale parameter that is based on the modified couple stress theory. Furthermore, it takes into account Casimir and van der Waals forces, and the associated electrostatic force with the first-order fringing field effects. The resulting nonlinear differential equations were converted to a coupled system of algebraic equations using the differential quadrature method. The outcome of our work shows the dramatic effect and dependence of the pull-in voltage of the FGM microbeam upon the temperature field, its gradient for a given boundary condition. Specifically, both uniform and non-uniform thermal loading can actuate the FGM microbeam even without an applied voltage. Our work also reveals that the non-uniform temperature field is more effective than the uniform temperature field in actuating a FGM cantilever-type microbeam. For the clamped-clamped case, care must be taken to account for the effective use of thermal loading in the design of microbeams. It is also observed that uniform thermal loading will lead to a reduction in the pull-in voltage of a FGM microbeam for all the three boundary conditions considered.

Fast plasma sintering delivers functional graded materials components with macroporous structures and osseointegration properties.

PubMed

Godoy, R F; Coathup, M J; Blunn, G W; Alves, A L; Robotti, P; Goodship, A E

2016-04-13

We explored the osseointegration potential of two macroporous titanium surfaces obtained using fast plasma sintering (FPS): Ti macroporous structures with 400-600 µmØ pores (TiMac400) and 850-1000 µmØ pores (TiMac850). They were compared against two surfaces currently in clinical use: Ti-Growth® and air plasma spray (Ti-Y367). Each surface was tested, once placed over a Ti-alloy and once onto a CoCr bulk substrate. Implants were placed in medial femoral condyles in 24 sheep. Samples were explanted at four and eight weeks after surgery. Push-out loads were measured using a material-testing system. Bone contact and ingrowth were assessed by histomorphometry and SEM and EDX analyses. Histology showed early osseointegration for all the surfaces tested. At 8 weeks, TiMac400, TiMac850 and Ti-Growth® showed deep bone ingrowth and extended colonisation with newly formed bone. The mechanical push-out force was equal in all tested surfaces. Plasma spray surfaces showed greater bone-implant contact and higher level of pores colonisation with new bone than FPS produced surfaces. However, the void pore area in FPS specimens was significantly higher, yet the FPS porous surfaces allowed a deeper osseointegration of bone to implant. FPS manufactured specimens showed similar osseointegration potential to the plasma spray surfaces for orthopaedic implants. FPS is a useful technology for manufacturing macroporous titanium surfaces. Furthermore, its capability to combine two implantable materials, using bulk CoCr with macroporous titanium surfaces, could be of interest as it enables designers to conceive and manufacture innovative components. FPS delivers functional graded materials components with macroporous structures optimised for osseointegration.

Wave propagation in embedded inhomogeneous nanoscale plates incorporating thermal effects

NASA Astrophysics Data System (ADS)

Ebrahimi, Farzad; Barati, Mohammad Reza; Dabbagh, Ali

2018-04-01

In this article, an analytical approach is developed to study the effects of thermal loading on the wave propagation characteristics of an embedded functionally graded (FG) nanoplate based on refined four-variable plate theory. The heat conduction equation is solved to derive the nonlinear temperature distribution across the thickness. Temperature-dependent material properties of nanoplate are graded using Mori-Tanaka model. The nonlocal elasticity theory of Eringen is introduced to consider small-scale effects. The governing equations are derived by the means of Hamilton's principle. Obtained frequencies are validated with those of previously published works. Effects of different parameters such as temperature distribution, foundation parameters, nonlocal parameter, and gradient index on the wave propagation response of size-dependent FG nanoplates have been investigated.

Direct-write graded index materials realized in protein hydrogels

DOE PAGES

Kaehr, Bryan; Scrymgeour, David A.

2016-09-20

Here, the ability to create optical materials with arbitrary index distributions would prove transformative for optics design and applications. However, current fabrication techniques for graded index (GRIN) materials rely on diffusion profiles and therefore are unable to realize arbitrary distribution GRIN design. Here, we demonstrate the laser direct writing of graded index structures in protein-based hydrogels using multiphoton lithography. We show index changes spanning a range of 10 –2, which is comparable with laser densified glass and polymer systems. Further, we demonstrate the conversion of these written density variation structures into SiO 2, opening up the possibility of transforming GRINmore » hydrogels to a wide range of material systems.« less

Direct-write graded index materials realized in protein hydrogels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaehr, Bryan; Scrymgeour, David A.

Here, the ability to create optical materials with arbitrary index distributions would prove transformative for optics design and applications. However, current fabrication techniques for graded index (GRIN) materials rely on diffusion profiles and therefore are unable to realize arbitrary distribution GRIN design. Here, we demonstrate the laser direct writing of graded index structures in protein-based hydrogels using multiphoton lithography. We show index changes spanning a range of 10 –2, which is comparable with laser densified glass and polymer systems. Further, we demonstrate the conversion of these written density variation structures into SiO 2, opening up the possibility of transforming GRINmore » hydrogels to a wide range of material systems.« less

Test-Enhanced Learning in the Classroom: Long-Term Improvements from Quizzing

ERIC Educational Resources Information Center

Roediger, Henry L., III; Agarwal, Pooja K.; McDaniel, Mark A.; McDermott, Kathleen B.

2011-01-01

Three experiments examined whether quizzing promotes learning and retention of material from a social studies course with sixth grade students from a suburban middle school. The material used in the experiments was the course material students were to learn and some of the dependent measures were the actual tests on which students received grades.…

Readability assessment of patient education materials from the American Academy of Otolaryngology--Head and Neck Surgery Foundation.

PubMed

Kasabwala, Khushabu; Agarwal, Nitin; Hansberry, David R; Baredes, Soly; Eloy, Jean Anderson

2012-09-01

Americans are increasingly turning to the Internet as a source of health care information. These online resources should be written at a level readily understood by the average American. This study evaluates the readability of online patient education information available from the American Academy of Otolaryngology--Head and Neck Surgery Foundation (AAO-HNSF) professional Web site using 7 different assessment tools that analyze the materials for reading ease and grade level of its target audience. Analysis of Internet-based patient education material from the AAO-HNSF Web site. Online patient education material from the AAO-HNSF was downloaded in January 2012 and assessed for level of readability using the Flesch Reading Ease, Flesch-Kincaid Grade Level, SMOG grading, Coleman-Liau Index, Gunning-Fog Index, Raygor Readability Estimate graph, and Fry Readability graph. The text from each subsection was pasted as plain text into Microsoft Word document, and each subsection was subjected to readability analysis using the software package Readability Studio Professional Edition Version 2012.1. All health care education material assessed is written between an 11th grade and graduate reading level and is considered "difficult to read" by the assessment scales. Online patient education materials on the AAO-HNSF Web site are written above the recommended 6th grade level and may need to be revised to make them more easily understood by a broader audience.

Microstructure and properties of aluminium-aluminium oxide graded composite materials

NASA Astrophysics Data System (ADS)

Kamaruzaman, F. F.; Nuruzzaman, D. M.; Ismail, N. M.; Hamedon, Z.; Iqbal, A. K. M. A.; Azhari, A.

2018-03-01

In this research works, four-layered aluminium-aluminium oxide (Al-Al2O3) graded composite materials were fabricated using powder metallurgy (PM) method. In processing, metal-ceramic graded composite materials of 0%, 10%, 20% and 30% weight percentage of ceramic concentration were prepared under 30 ton compaction load using a cylindrical die-punch set made of steel. After that, two-step pressureless sintering was carried out at sintering temperature and time 600°C and 3 hours respectively. It was observed that the sintered cylindrical specimens of 30 mm diameter were prepared successfully. The graded composite specimens were analysed and the properties such as density, microstructure and hardness were measured. It was found that after sintering process, the diameter of the graded cylindrical structure was decreased. Using both Archimedes method and rule of mixture (ROM), he density of structure was measured. The obtained results revealed that the microvickers hardness was increased as the ceramic component increases in the graded layer. Moreover, it was observed that the interface of the graded structure is clearly distinguished within the multilayer stack and the ceramic particles are almost uniformly distributed in the Al matrix.

Differential Item Functioning by Gender on a Large-Scale Science Performance Assessment: A Comparison across Grade Levels.

ERIC Educational Resources Information Center

Holweger, Nancy; Taylor, Grace

The fifth-grade and eighth-grade science items on a state performance assessment were compared for differential item functioning (DIF) due to gender. The grade 5 sample consisted of 8,539 females and 8,029 males and the grade 8 sample consisted of 7,477 females and 7,891 males. A total of 30 fifth grade items and 26 eighth grade items were…

Meeting Radiation Protection Requirements and Reducing Spacecraft Mass - A Multifunctional Materials Approach

NASA Technical Reports Server (NTRS)

Atwell, William; Koontz, Steve; Reddell, Brandon; Rojdev, Kristina; Franklin, Jennifer

2010-01-01

Both crew and radio-sensitive systems, especially electronics must be protected from the effects of the space radiation environment. One method of mitigating this radiation exposure is to use passive-shielding materials. In previous vehicle designs such as the International Space Station (ISS), materials such as aluminum and polyethylene have been used as parasitic shielding to protect crew and electronics from exposure, but these designs add mass and decrease the amount of usable volume inside the vehicle. Thus, it is of interest to understand whether structural materials can also be designed to provide the radiation shielding capability needed for crew and electronics, while still providing weight savings and increased useable volume when compared against previous vehicle shielding designs. In this paper, we present calculations and analysis using the HZETRN (deterministic) and FLUKA (Monte Carlo) codes to investigate the radiation mitigation properties of these structural shielding materials, which includes graded-Z and composite materials. This work is also a follow-on to an earlier paper, that compared computational results for three radiation transport codes, HZETRN, HETC, and FLUKA, using the Feb. 1956 solar particle event (SPE) spectrum. In the following analysis, we consider the October 1989 Ground Level Enhanced (GLE) SPE as the input source term based on the Band function fitting method. Using HZETRN and FLUKA, parametric absorbed doses at the center of a hemispherical structure on the lunar surface are calculated for various thicknesses of graded-Z layups and an all-aluminum structure. HZETRN and FLUKA calculations are compared and are in reasonable (18% to 27%) agreement. Both codes are in agreement with respect to the predicted shielding material performance trends. The results from both HZETRN and FLUKA are analyzed and the radiation protection properties and potential weight savings of various materials and materials lay-ups are compared.

Impact of functionalized particle structure on roll compaction/dry granulation and tableting of calcium carbonate.

PubMed

Grote, Simon; Kleinebudde, Peter

2018-06-10

The influence of a functionalized raw material particle structure on the granulation behavior and tabletabilty of calcium carbonate (CaCO 3 ) was investigated. Therefore, a milled grade of CaCO 3 was compared to different binary mixtures of milled and functionalized CaCO 3 . Relevant properties of raw materials, ribbons and granules were measured. The starting materials and two fractions of dry granules were compressed to tablets. The tabletability of granules was compared to that of the powders and the influence of specific compaction force and granule size on tablet tensile strength was evaluated. Adding functionalized particles drastically influenced the granulation and tableting behavior of CaCO 3 . Increasing proportions increased the ribbon porosity and granule size. Tensile strength of tablets from powder mixtures and granules was increased as well. Nevertheless, adding functionalized CaCO 3 led to a loss in tabletability induced by a previous compaction step to an extent depending on its proportion in the formulation. A clear influence of the particle morphology on granulation and tableting behavior was demonstrated by the study. The functionalized structure showed aspects of a more plastic deformation behavior. Adding functionalized CaCO 3 to a mixture, even in small amounts, seemed to be beneficial to increase granule size and tablet strength. Copyright © 2018 Elsevier B.V. All rights reserved.

The surface crack problem for a functionally graded coating bonded to a homogeneous layer

NASA Astrophysics Data System (ADS)

Kasmalkar, Maheendra B.

In the continuing search for materials which can withstand the grueling requirements of modern day applications, Functionally Graded Materials (FGMs) seem to be a promising alternative to conventional materials. These nonhomogeneous materials offer better interfacial properties by improving bond strength and reducing thermal mismatch. Before putting these materials into application, an important step in the design of FGMs is the stress analysis and fracture characterization. The fracture performance of FGM coatings on homogeneous substrates is the focus of this study. In this study, various internal and surface crack configurations in the coating and the substrate are subjected to mechanical and thermal loads. The analysis is linear elastic. The thermo-mechanical properties of the FGM coating are assumed to vary exponentially with the spatial coordinate. The equilibrium equations are solved using integral transforms. The resulting singular integral equations are solved using numerical integration. The results of interest for this mode I formulation are the stress intensity factors and the crack opening displacements. The effects of the nonhomogeneity parameter and various dimensionless length parameters are studied. One of the most important outcomes of this study is the theoretical proof that "kink" in material property at the interface does not introduce any singularity. In the numerical results it is observed that generally the stress intensity factors tend to increase with material nonhomogeneity. Also, it is observed that the substrate thickness tends to suppress cracking in the coating. In pure thermal loading, the surface cracks may either be arrested or there might be crack closure. The stress intensity factors from different loadings can be added up to obtain the resultant stress intensity factor for multiple loading. Results in this study have wide-ranging applications. They can be applied to thermal barrier coatings on turbine components, combustion chambers, parts of the airframe for the "Space Plane", soil mechanics, bone fractures and many more applications where the material is macroscopically nonhomogeneous. Thus this study solves a basic problem common to a variety of applications in diverse fields.

Processing and Characterization of Functionally Graded Aluminum (A319)—SiCp Metallic Composites by Centrifugal Casting Technique

NASA Astrophysics Data System (ADS)

Jayakumar, E.; Jacob, Jibin C.; Rajan, T. P. D.; Joseph, M. A.; Pai, B. C.

2016-08-01

Functionally graded materials (FGM) are successfully adopted for the design and fabrication of engineering components with location-specific properties. The present study describes the processing and characterization of A319 Aluminum functionally graded metal matrix composites (FGMMC) with 10 and 15 wt pct SiCp reinforcements. The liquid stir casting method is used for composite melt preparation followed by FGMMC formation by vertical centrifugal casting method. The process parameters used are the mold preheating temperature of 523 K (250 °C), melt pouring temperature of 1013 K (740 °C), and mold rotation speed of 1300 rpm. The study analyzes the distribution and concentration of reinforcement particles in the radial direction of the FGMMC disk along with the effects of gradation on density, hardness, mechanical strength, the variation in coefficient of thermal expansion and the wear resistance properties at different zones. Microstructures of FGMMC reveal an outward radial gradient distribution of reinforcements forming different zones. Namely, matrix-rich inner, transition, particles-rich outer, and chill zone of a few millimeters thick at the outer most periphery of the casting are formed. From 10-FGM, a radial shift in the position of SiCp maxima is observed in 15-FGM casting. The mechanical characterization depicts enhanced properties for the particle-rich zone. The hardness shows a graded nature in correlation with particle concentration and a maximum of 94.4 HRB has been obtained at the particle-rich region of 15-FGM. In the particle-rich zone, the lowest CTE value of 20.1 µm/mK is also observed with a compressive strength of 650 MPa and an ultimate tensile strength of 279 MPa. The wear resistance is higher at the particle-rich zone of the FGMMC.

HOTCFGM-2D: A Coupled Higher-Order Theory for Cylindrical Structural Components with Bi-Directionally Components with Bi-Directionally Graded Microstructures

NASA Technical Reports Server (NTRS)

Pindera, Marek-Jerzy; Aboudi, Jacob

2000-01-01

The objective of this two-year project was to develop and deliver to the NASA-Glenn Research Center a two-dimensional higher-order theory, and related computer codes, for the analysis and design of cylindrical functionally graded materials/structural components for use in advanced aircraft engines (e.g., combustor linings, rotor disks, heat shields, brisk blades). To satisfy this objective, two-dimensional version of the higher-order theory, HOTCFGM-2D, and four computer codes based on this theory, for the analysis and design of structural components functionally graded in the radial and circumferential directions were developed in the cylindrical coordinate system r-Theta-z. This version of the higher-order theory is a significant generalization of the one-dimensional theory, HOTCFGM-1D, developed during the FY97 for the analysis and design of cylindrical structural components with radially graded microstructures. The generalized theory is applicable to thin multi-phased composite shells/cylinders subjected to steady-state thermomechanical, transient thermal and inertial loading applied uniformly along the axial direction such that the overall deformation is characterized by a constant average axial strain. The reinforcement phases are uniformly distributed in the axial direction, and arbitrarily distributed in the radial and circumferential direction, thereby allowing functional grading of the internal reinforcement in the r-Theta plane. The four computer codes fgmc3dq.cylindrical.f, fgmp3dq.cylindrical.f, fgmgvips3dq.cylindrical.f, and fgmc3dq.cylindrical.transient.f are research-oriented codes for investigating the effect of functionally graded architectures, as well as the properties of the multi-phase reinforcement, in thin shells subjected to thermomechanical and inertial loading, on the internal temperature, stress and (inelastic) strain fields. The reinforcement distribution in the radial and circumferential directions is specified by the user. The thermal and inelastic properties of the individual phases can vary with temperature. The inelastic phases are presently modeled by the power-law creep model generalized to multi-directional loading (within fgmc3dq.cylindrical.f and fgmc3dq.cylindrical.transient.f for steady-state and transient thermal loading, respectively), and incremental plasticity and GVIPS unified viscoplasticity theories (within the steady-state loading versions fgmp3dq.cylindrical.f and fgmgvips3dq.cylindrical.f).

Malignant Gastroduodenal Obstruction: Treatment with Self-Expanding Uncovered Wallstent

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gutzeit, Andreas, E-mail: Andreas.Gutzeit@ksw.ch; Binkert, Christoph A.; Schoch, Eric

2009-01-15

Purpose: To retrospectively evaluate the clinical effectiveness of a self-expanding uncovered Wallstent in patients with malignant gastroduodenal obstruction. Materials and Methods: Under combined endoscopic and fluoroscopic guidance, 29 patients with a malignant gastroduodenal stenosis were treated with a self-expanding uncovered metallic Wallstent. A dysphagia score was assessed before and after the intervention to measure the success of this palliative therapy. The dysphagia score ranged between grade 0 to grade 4: grade 0 = able to tolerate solid food, grade 1 = able to tolerate soft food, grade 2 = able to tolerate thick liquids, grade 3 = able to toleratemore » water or clear fluids, and grade 4 = unable to tolerate anything perorally. Stent patency and patients survival rates were calculated. Results: The insertion of the gastroduodenal stent was technically successful in 28 patients (96.5%). After stenting, 25 patients (86.2%) showed clinical improvement by at least one score point. During follow-up, 22 (78.5%) of 28 patients showed no stent occlusion until death and did not have to undergo any further intervention. In six patients (20.6%), all of whom were treated with secondary stent insertions, occlusion with tumor ingrowth and/or overgrowth was observed after the intervention. The median period of primary stent patency in our study was 240 days. Conclusion: Placement of an uncovered Wallstent is clinically effective in patients with malignant gastroduodenal obstruction. Stent placement is associated with high technical success, good palliation effect, and high durability of stent function.« less

Suitability of asthma education materials for school-age children: Implications for health literacy.

PubMed

Tzeng, Yu-Fen; Gau, Bih-Shya

2018-03-01

To investigate the suitability of asthma education materials for school-age children with asthma and elucidate how these children used their health-literacy abilities to identify whether the materials can be accepted, comprehended and applied. Effective asthma self-management education is influenced by the suitability of materials and an individual's health literacy. A mixed-method research design was developed using quantitative and qualitative surveys. The suitability of the materials was assessed on the basis of the Chinese version of the Suitability Assessment of Materials by five experts. In addition, five school-age children (age: 8-12 years) were recruited and interviewed. In total, 25 pieces of asthma education material for children were collected. On the basis of their type, the materials were categorised as nine brochures, 11 leaflets and five videos. Of the 25 materials, 17 were rated as superior materials, whereas eight were rated as adequate materials. The suitability scores of the video-based materials were significantly higher than those of the brochures and leaflets (p = .006). One print material was considered to have a reading level suitable for fifth-grade or younger children, whereas the remaining materials were considered suitable for sixth-grade or older children. The following six health-literacy domains were identified: recognising asthma through body knowledge, posing reflective questions, identifying self-care difficulties, receiving adult guidance, learning with enjoyment and addressing learning requirements. The video-based materials had integrated content and were appealing to children. Cartoon animations, interactive computer games, and skill demonstrations may enhance learning stimulation and motivation and increase learning effects in children. The present results may help healthcare providers to understand children's capacities to manage their disease, effectively address children's requirements and function as a key resource for children to strengthen their literacy in asthma management. © 2017 John Wiley & Sons Ltd.

The Grading System: Does an "A" Really Equal Learning?

ERIC Educational Resources Information Center

Haley, Beverly

1988-01-01

Good grades on a report card do not necessarily mean the material has been comprehended. This article examines the relative worth of grades; extra credit assignments; categorizing students into A, B, or C boxes; and the role of parental pressures for higher grades. Grading systems should be subordinate to true learning motivation. (MLH)

Magnetic anisotropy at material interfaces

NASA Astrophysics Data System (ADS)

Greene, Peter Kevin

In this dissertation, a comprehensive set of depth dependent magnetic measurements, as well as structural characterizations, were carried out on the Co/Pd multilayer system. The first-order reversal curve (FORC) technique is applied extensively to identify reversal mechanisms and different reversal phases within the material. In particular, the extension of the FORC technique to x-ray magnetic circular dichroism (XMCD) as a surface sensitive technique that identifies reversible magnetization change was performed for the first time. Polarized neutron reflectivity (PNR) was also used to directly measure the magnetization as a function of depth. The effects of deposition pressure grading within the Co/Pd multilayers were investigated. Structures were graded with three distinct pressure regions. FORC analysis shows that not only does increasing the deposition pressure increase the coercivity and effective anisotropy within that region, but also the order in which the pressure is changed also affects the entire structure. Layers grown at high sputtering pressures tend to reverse via domain wall pinning and rotation while those grown at lower pressures reverse via rapid domain wall propagation laterally across the film. Having high pressure layers underneath low pressure layers causes disorder to vertically propagate and lessen the induced anisotropy gradient. This analysis is confirmed by depth dependent magnetization profiles obtain from PNR. Continuously pressure-graded Co/Pd multilayers were then sputtered at two incident angles onto porous aluminum oxide templates with different pore aspect ratios. The effects of pressure grading versus uniform low pressure deposition is studied, as well as the effect of the angle of the incident deposition flux. The coercivity of the pressure graded perpendicular flux sample is compared to the low pressure sample. Additionally the effect of deposition angle and pore sidewall deposition is investigated. It is shown that sidewall deposition strongly affects the reversal behavior. As another way to induce a vertical anisotropy gradient, Co/Pd multilayers were bombarded with Ar+ ions at different energies and fluences. The effects of the depth dependent structural damage as a function of irradiation conditions were investigated. It is shown that the structural damage weakens the perpendicular anisotropy of the surface layers, causing a tilting of the surface magnetic moment into the plane of the film. The surface behavior is explicitly measured and shown to have a significant tilting angle in the top 5 nm depending on irradiation energy and fluence. Continuing the study of vertical anisotropy gradients in Co/Pd multilayers, multilayers with varied Co thickness were studied. Four films with varying Co thickness profiles were created and then patterned into nanodot arrays with diameters between 700 nm and 70 nm. The different films were graded continuously, or in stacks with varying Co thicknesses. An anisotropy gradient is shown to be established in the graded samples, and the switching field is lowered as a result. Furthermore, in the continuously graded samples the magnetization reversal behavior is fundamentally different from all other samples. The thermal energy barriers are measured in the uniform and continuously graded samples, yielding similar results. Finally, the establishment of exchange anisotropy at the ferromagnet / antiferromagnet (FM/AFM) interface in the epitaxial Fe/CoO system is investigated as a function of AFM thickness. The establishment of frozen AFM moments is analyzed using the FORC technique. The FORC technique combined with vector coil measurements also shows the transition from rotatable AFM to pinned AFM moments and suggests a mechanism of winding domain walls within the bulk AFM. (Abstract shortened by UMI.).

Continuously graded extruded polymer composites for energetic applications fabricated using twin-screw extrusion processing technology

NASA Astrophysics Data System (ADS)

Gallant, Frederick M.

A novel method of fabricating functionally graded extruded composite materials is proposed for propellant applications using the technology of continuous processing with a Twin-Screw Extruder. The method is applied to the manufacturing of grains for solid rocket motors in an end-burning configuration with an axial gradient in ammonium perchlorate volume fraction and relative coarse/fine particle size distributions. The fabrication of functionally graded extruded polymer composites with either inert or energetic ingredients has yet to be investigated. The lack of knowledge concerning the processing of these novel materials has necessitated that a number of research issues be addressed. Of primary concern is characterizing and modeling the relationship between the extruder screw geometry, transient processing conditions, and the gradient architecture that evolves in the extruder. Recent interpretations of the Residence Time Distributions (RTDs) and Residence Volume Distributions (RVDs) for polymer composites in the TSE are used to develop new process models for predicting gradient architectures in the direction of extrusion. An approach is developed for characterizing the sections of the extrudate using optical, mechanical, and compositional analysis to determine the gradient architectures. The effects of processing on the burning rate properties of extruded energetic polymer composites are characterized for homogeneous formulations over a range of compositions to determine realistic gradient architectures for solid rocket motor applications. The new process models and burning rate properties that have been characterized in this research effort will be the basis for an inverse design procedure that is capable of determining gradient architectures for grains in solid rocket motors that possess tailored burning rate distributions that conform to user-defined performance specifications.

Preparation and characterization of 6-layered functionally graded nickel-alumina (Ni-Al2O3) composites

NASA Astrophysics Data System (ADS)

Latiff, M. I. A.; Nuruzzaman, D. M.; Basri, S.; Ismail, N. M.; Jamaludin, S. N. S.; Kamaruzaman, F. F.

2018-04-01

The present research study deals with the preparation of 6-layered functionally graded (FG) metal-ceramic composite materials through powder metallurgy technique. Using a cylindrical die-punch set made of steel, the nickel-alumina (Ni-Al2O3) graded composite structure was fabricated. The samples consist of four gradual inter layers of varied nickel composition (80wt.%, 60wt.%, 40wt.%, 20wt.%) sandwiched with pure Ni and Al2O3 powders at the ends (100wt.% and 0wt.% nickel) were fabricated under 30 ton compaction load using a hydraulic press. After that, two-step sintering was carried out at sintering temperature 1200ºC and soaking time 3 hours was maintained in a tube furnace. The properties of the prepared samples were characterized by radial shrinkage, optical microscopy and hardness testing. Results showed that larger shrinkage occurred within the ceramic phase which proves that more porosities were eliminated in the ceramic rich layers. From the microstructural analysis, it was observed that alumina particles are almost uniformly distributed in nickel matrix, so as nickel particles in the ceramic matrix of alumina-dominant layers. From interfacial analyses, it was observed that a smooth transition in microstructure from one layer to the next confirms a good interfacial solid state bonding between metal-ceramic constituents and good compaction process. On the other hand, microhardness test results suggest that there might be increasing percentage of porosities in the graded structure as the ceramic content rises.

Stress Intensity Formulas for Three Dimensional Crack in the Vicinity of an Interface

NASA Astrophysics Data System (ADS)

Noda, Nao-Aki; Liang, Bin; Xu, Chunhui

2008-02-01

In this study, stress intensity factors are considered by using exact solutions available for cracks near an interface. The effect of crack shape on the stress intensity factors is studied with varying the aspect ratio of the cracks. Then, the stress intensity factors are expressed as formulas useful for engineering applications. The stress intensity factors for interface cracks and a crack in a functionally graded material are also discussed.

COLLABORATIVE RESEARCH AND DEVELOPMENT (CR&D) Delivery Order 0060: Gradient Materials Morphology Modeling Support

DTIC Science & Technology

2007-08-01

antiplane eigenstrain . ASME Journal of Applied Mechanics (In press, to appear in the September issue). [4] Wang, X., Pan, E., Roy, A. K, 2007. Three...problem of a functionally graded plane with a circular inclusion under a uniform antiplane eigenstrain is investigated, where the shear modulus varies...strain and stress fields inside the circular inclusion under uniform antiplane eigenstrains are intrinsically nOliuniform. This phenomenon differs

The Swedish infant high-grade reflux trial: Study presentation and vesicoureteral reflux outcome.

PubMed

Nordenström, Josefin; Holmdahl, Gundela; Brandström, Per; Sixt, Rune; Stokland, Eira; Sillén, Ulla; Sjöström, Sofia

2017-04-01

High-grade vesicoureteral reflux (VUR) in infants is associated with congenital renal abnormalities, recurrent UTI, and bladder dysfunction. Endoscopic treatment (ET) is a well-established method in children with low to moderate reflux grades, but there is a lack of randomised controlled trials regarding the use of ET versus continuous antibiotic prophylaxis in infants with high-grade VUR. This study aimed to determine whether high-grade VUR in infants can be treated with endoscopic injection and whether ET is superior to antibiotic prophylaxis in the treatment of VUR. This prospective, randomised, controlled, multicentre, 1-year follow-up trial comprised 77 infants (55 boys, 22 girls) <8 months of age with VUR grade 4-5 (n = 30/n = 47). Of the infants, 52 (68%) had bilateral VUR. Thirty-nine were randomised to antibiotic prophylaxis and 38 to ET (with prophylaxis until resolution). Voiding cystourethrogram, ultrasound, renal scintigraphy, and free voiding observation were performed at study entry and after 1 year to evaluate VUR grade, and renal and bladder function. VUR grade ≤2 was seen in 22 (59%) infants in the endoscopy group and eight (21%) in the prophylaxis group at follow-up (p = 0.0014). The success rate in the endoscopy group was 100% in unilateral grade 4, falling to 31% in bilateral grade 5 (p = 0.0094). Correspondingly, the results in the prophylaxis group were 40% in grade 4 down to 0% in bilateral grade 5 (p = 0.037) (Table). Logistic regression analyses identified ET, VUR grade 4, unilaterality, and low residual urine at baseline as positive predictors of VUR down-grading to ≤2 (area under ROC curve 0.88). In four patients with reflux resolution after one injection, dilating reflux recurred at the 1-year follow-up. One patient had a UTI possibly related to ET. In our material four patients required re-implantation, of whom one was obstructive after injection. The opportunity to offer even small infants with high-grade VUR an alternative, minimally invasive treatment option is a great advance in paediatric urology. In this high-risk group, bilateral VUR grade 5 stands out with its poor bladder function and low chance of resolution. The recurrence rate of dilating VUR after successful ET is consistent with previous studies. The limitations are the relatively small number of patients and the short follow-up. High-grade VUR in infants can be treated with injection therapy and the resolution rate is higher than that of prophylaxis treatment. The complication rate is low and VUR grade 4, unilaterality, and low residual urine are favourable for the resolution and down-grading of VUR. Copyright © 2016 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Evaluation and modeling of aerodynamic properties of mung bean seeds

NASA Astrophysics Data System (ADS)

Shahbazi, Feizollah

2015-01-01

Aerodynamic properties of solid materials have long been used to convey and separate seeds and grains during post harvest operations. The objective of this study was the evaluation of the aerodynamic properties of mung bean seeds as a function of moisture content and two grades referred to above and below a cut point of 4.8 mm in length. The results showed that as the moisture content increased from 7.8 to 25% (w.b.), the terminal velocity of seeds increased following a polynomial relationship, from 7.28 to 8.79 and 6.02 to 7.12 m s-1, for grades A and B, respectively. Seeds at grade A had terminal velocities with a mean value of 8.05 m s-1, while at grade B had a mean value of 6.46 m s-1. The Reynolds number of both grades increased linearly with the increase of seeds moisture content, while the drag coefficient decreased with the increase of moisture content. Mathematical relationships were developed to relate the change in seeds moisture content with the obtained values of aerodynamic properties. The analysis of variance showed that moisture content had a significant effect, at 1% probability level, on all the aerodynamics properties of mung beans.

Buckling of graded coatings: A continuum model

NASA Astrophysics Data System (ADS)

Chiu, Tz-Cheng

2000-12-01

Requirements for the protection of hot section components in many high temperature applications such as earth-to-orbit winged planes and advanced turbine systems have led to the application of thermal barrier coatings (TBCs) that utilize ceramic coatings on metal substrates. An alternative concept to homogeneous ceramic coatings is the functionally graded materials (FGM) in which the composition of the coating is intentionally graded to improve the bonding strength and to reduce the magnitude of the residual and thermal stresses. A widely observed failure mode in such layered systems is known to be interface cracking that leads to spallation fracture. In most cases, the final stage of the failure process for a thin coating appears to be due to buckling instability under thermally or mechanically induced compressive stress. The objective of this study is to develop a solution to the buckling instability problem by using continuum elasticity rather than a structural mechanics approach. The emphasis in the solution will be on the investigation of the effect of material inhomogeneity in graded coatings on the instability load, the postbuckling behavior, and fracture mechanics parameters such as the stress intensity factors and strain energy release rate. In this analysis, a nonlinear continuum theory is employed to examine the interface crack problem. The analytical solution of the instability problem permits the study of the effect of material inhomogeneity upon the inception of buckling and establishes benchmark results for the numerical solutions of related problems. To study the postbuckling behavior and to calculate the stress intensity factors and strain energy release rate a geometrically nonlinear finite element procedure with enriched crack-tip element is developed. Both plane strain and axisymmetric interface crack problems in TBCs with either homogeneous or graded coating are then considered by using the finite element procedure. It is assumed that the applied load is a uniform temperature drop. Comparison of the results with that obtained from the plate approximation shows that because of the higher constraints the plate theory predicts greater instability strains and lower strain energy release rates. It is also observed that compared with a homogeneous coating the graded coating gives lower strain energy release rate because of the lower thermal residual stress and higher bending stiffness. (Abstract shortened by UMI.)

The Cloze Procedure for Improving Sixth Grade Students' Reading Comprehension and Understanding of Social Studies Materials.

ERIC Educational Resources Information Center

Grant, Patricia

This study attempted to determine whether systematic inclusion of cloze exercises in a sixth grade social studies unit would influence students' reading growth, long term recall, and interest in the material. During the nine-week study, 21 students in the experimental group and 21 students in the control group read the same materials; after each…

Computer Literacy. A Co-Ser Project of Cortland-Madison BOCES, Summer 1983.

ERIC Educational Resources Information Center

Rausa, Tom; And Others

This project was designed to prepare curriculum materials that can be used to teach general computer literacy and rudimentary programming for grades 7 and 8. The intended audience for these materials is the grade 7 and 8 teacher who is not experienced in computer literacy or programming. Materials provided include, in separate sections for the two…

High-temperature elastic-plastic and creep properties for SA533 Grade B Class I and SA508 materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reddy, G.B.; Ayres, D.J.

1982-12-01

High temperature elastic-plastic and creep properties are presented for SA533 Grade B Class I and SA508 Class II materials. These properties are derived from tests conducted at Combustion Engineering Material and Metallurgical Laboratories and cover the temperature range of 70/sup 0/F to 1200/sup 0/F.

DECS tries out instructional materials on AIDS prevention education.

PubMed

1994-01-01

A national try-out of the newly developed print and non-print instructional materials on AIDS Education is being conducted by the Department of Education, Culture and Sports (DECS) this school year 1993-to 1994. To determine the effectiveness of these materials, various public and private schools in Region IV (Southern Tagalog), VII (Central Visayas) XI (Southern Mindanao) and National Capital Region (Metro, Manila) were chosen as try-out institutions. The AIDS education materials will be tried out in different subjects in some grade and year levels such as civics and culture (grade one); science and health (grades three and six); home economics and livelihood education (grade five); physical education, health and music (second year) and Pilipino Language (third year). The materials for the elementary level consist of posters, cut-out pictures, voice tapes, jingles, talking books and slides, while the secondary school level utilizes modules. For the tertiary level, a Resource Book on AIDS Prevention Education is used by the Teacher Training Institutions and the Non-Formal Education employs the Facilitator's Guide for Levels I-III. These materials will be tried out in both urban and rural schools, with control school and experimental school at each level. full text

The Concept of Culture. Teacher's Background Material for the American, the Arunta, the Kazak. Grade One and Grade Four. Publications No. 3, 4 and 5.

ERIC Educational Resources Information Center

Hunt, Anne; And Others

This guide presents background material to acquaint elementary social studies teachers with the cultural systems of the Arunta and Kazak tribes and the more technologically sophisticated American way of life. It is part of the Anthropology Curriculum Project and is designed to be used in conjunction with curriculum guides for grades 1 and 4 (SO…

Sociology.

ERIC Educational Resources Information Center

Bensalam Township School District, Cornwells Heights, PA.

GRADES OR AGES: High school (grades not specified). SUBJECT MATTER: Sociology. ORGANIZATION AND PHYSICAL APPEARANCE: The course contains 13 units. The material is set out in columns--content, student activities, time, teacher activity or strategy, materials, and evaluation. The guide is mimeographed and spiral bound with a soft cover. OBJECTIVES…

Psychology.

ERIC Educational Resources Information Center

Bensalam Township School District, Cornwells Heights, PA.

GRADES OR AGES: High school (grades not specified). SUBJECT MATTER: Psychology. ORGANIZATION AND PHYSICAL APPEARANCE: The course contains 12 units. The material is set out in columns--content, student activities, time, teacher activity or strategy, materials, and evaluation. The guide is mimeographed and spiral bound with a soft cover. OBJECTIVES…

Strategies Unlimited.

ERIC Educational Resources Information Center

Blaga, Jeff; And Others

Designed primarily for teachers of students in grades 7-12, the document presents over 60 social studies teaching strategies and lesson plans. Each lesson includes an overview, grade level information, suggested course/subject matter uses, objectives, suggested materials, student materials, and an instructional plan. Lesson topics fall into the…

Evaluating Sermons: The Function of Grades in Teaching Preaching

ERIC Educational Resources Information Center

Helsel, Carolyn Browning

2017-01-01

What are grades doing in a homiletics classroom? This article traces the function of grades through the broader history of the educational system in the United States and then makes suggestions for how grades can be used more effectively in teaching preaching. Beginning in the nineteenth century, teachers used grades to rank and motivate students,…

Readability of Orthopaedic Patient-reported Outcome Measures: Is There a Fundamental Failure to Communicate?

PubMed

Perez, Jorge L; Mosher, Zachary A; Watson, Shawna L; Sheppard, Evan D; Brabston, Eugene W; McGwin, Gerald; Ponce, Brent A

2017-08-01

Patient-reported outcome measures (PROMs) are increasingly used to quantify patients' perceptions of functional ability. The American Medical Association and NIH suggest patient materials be written at or below 6th to 8th grade reading levels, respectively, yet one recent study asserts that few PROMs comply with these recommendations, and suggests that the majority of PROMs are written at too high of a reading level for self-administered patient use. Notably, this study was limited in its use of only one readability algorithm, although there is no commonly accepted, standard readability algorithm for healthcare-related materials. Our study, using multiple readability equations and heeding equal weight to each, hopes to yield a broader, all-encompassing estimate of readability, thereby offering a more accurate assessment of the readability of orthopaedic PROMS. (1) What proportion of orthopaedic-related PROMs and orthopaedic-related portions of the NIH Patient Reported Outcomes Measurement Information System (PROMIS ® ) are written at or below the 6th and 8th grade levels? (2) Is there a correlation between the number of questions in the PROM and reading level? (3) Using systematic edits based on guidelines from the Centers for Medicare and Medicaid Services, what proportion of PROMs achieved American Medical Association and NIH-recommended reading levels? Eighty-six (86) independent, orthopaedic and general wellness PROMs, drawn from commonly referenced orthopaedic websites and prior studies, were chosen for analysis. Additionally, owing to their increasing use in orthopaedics, four relevant short forms, and 11 adult, physical health question banks from the PROMIS ® , were included for analysis. All documents were analyzed for reading grade levels using 19 unique readability algorithms. Descriptive statistics were performed using SPSS Version 22.0. The majority of the independent PROMs (64 of 86; 74%) were written at or below the 6th grade level, with 81 of 86 (94%) written at or below the 8th grade level. All item banks (11 of 11) and short forms (four of four) of the PROMIS ® were written below the 6th grade reading level. The median reading grade level of the 86 independent PROMs was 5.0 (interquartile range [IQR], 4.6-6.1). The PROMIS ® question banks had a median reading grade level of 4.1 (IQR, 3.5-4.8); the Adult Short Forms had a median reading grade level of 4.2 (IQR, 4.2-4.3) There was no correlation appreciated between the median reading grade level and the number of questions contained in a PROM (r = -0.081; p = 0.460). For PROMs above NIH-recommended levels, following edits, all (five of five) achieved NIH reading level goals and three (three of five) achieved American Medical Association goals. Editing of these PROMs improved readability by 4.3 median grade level (before, 8.9 [IQR, 8.4-9.1], after 4.6 [IQR, 4.6-6.4], difference of medians, 4.3; p = 0.008). Patient literacy has great influence on healthcare outcomes, and readability is an important consideration in all patient-directed written materials. Our study found that more than 70% of PROMs commonly used in orthopaedics, and all orthopaedic-related portions of the PROMIS ® are written at or below the most stringent recommendations (≤ 6th grade reading level), and more than 90% of independent PROMs and all PROMIS ® materials are written at or below an 8th grade level. Additionally, the use of the Centers for Medicare and Medicaid Services guidelines for editing high reading level PROMs yields satisfactory results. Fears of widely incomprehensible PROMs may be unfounded. Future research to identify the most appropriate readability algorithm for use in the healthcare sector, and revalidation of PROMs after readability-improving edits is warranted.

ALBI versus Child-Pugh grading systems for liver function in patients with hepatocellular carcinoma.

PubMed

Na, Seong K; Yim, Sun Y; Suh, Sang J; Jung, Young K; Kim, Ji H; Seo, Yeon S; Yim, Hyung J; Yeon, Jong E; Byun, Kwan S; Um, Soon H

2018-04-01

The prognostic performance of the albumin-bilirubin (ALBI) grade in hepatocellular carcinoma (HCC) as an objective method of assessing liver function was investigated. Data from 2099 patients with HCC in Korea were collected and analyzed retrospectively. The discriminative performance of ALBI grade was compared with Child-Pugh (C-P) grade for different stages or treatments. The median follow up duration was 16.2 months (range: 1.0-124.9). The median survival times were 49.7 months for C-P grade A (65.8%), 12.4 months for C-P grade B (25.5%), and 4.2 months for C-P grade C (8.6%) (P < 0.001). The median survival times were 84.2 months for ALBI grade 1 (32.8%), 25.5 months for ALBI grade 2 (53.5%), and 7.7 months for ALBI grade 3 (13.7%) (P < 0.001). In early UICC stages, ALBI grade showed better discriminative performance than C-P grade. In curative treatments, ALBI grade also showed better discriminative performance than C-P grade (Harrell's C: 0.624 (C-P grade) vs 0.667 [ALBI grade]). ALBI grade provided better prognostic performance in survival analysis and better distribution of the grades than C-P grade in HCC, suggesting that ALBI grade could be a good alternative grading system for liver function in patients with HCC. © 2018 Wiley Periodicals, Inc.

Colorado Student Assessment Program: 2001 Released Passages, Items, and Prompts. Grade 4 Reading and Writing, Grade 4 Lectura y Escritura, Grade 5 Mathematics and Reading, Grade 6 Reading, Grade 7 Reading and Writing, Grade 8 Mathematics, Reading and Science, Grade 9 Reading, and Grade 10 Mathematics and Reading and Writing.

ERIC Educational Resources Information Center

Colorado State Dept. of Education, Denver.

This document contains released reading comprehension passages, test items, and writing prompts from the Colorado Student Assessment Program for 2001. The sample questions and prompts are included without answers or examples of student responses. Test materials are included for: (1) Grade 4 Reading and Writing; (2) Grade 4 Lectura y Escritura…

Process Of Bonding Copper And Tungsten

DOEpatents

Slattery, Kevin T.; Driemeyer, Daniel E.; Davis, John W.

2000-07-18

Process for bonding a copper substrate to a tungsten substrate by providing a thin metallic adhesion promoting film bonded to a tungsten substrate and a functionally graded material (FGM) interlayer bonding the thin metallic adhesion promoting film to the copper substrate. The FGM interlayer is formed by sintering a stack of individual copper and tungsten powder blend layers having progressively higher copper content/tungsten content, by volume, ratio values in successive powder blend layers in a lineal direction extending from the tungsten substrate towards the copper substrate. The resulting copper to tungsten joint well accommodates the difference in the coefficient of thermal expansion of the materials.

Mitigating the Effects of the Space Radiation Environment: A Novel Approach of Using Graded-Z Materials

NASA Technical Reports Server (NTRS)

Atwell, William; Rojdev, Kristina; Aghara, Sukesh; Sriprisan, Sirikul

2013-01-01

In this paper we present a novel space radiation shielding approach using various material lay-ups, called "Graded-Z" shielding, which could optimize cost, weight, and safety while mitigating the radiation exposures from the trapped radiation and solar proton environments, as well as the galactic cosmic radiation (GCR) environment, to humans and electronics. In addition, a validation and verification (V&V) was performed using two different high energy particle transport/dose codes (MCNPX & HZETRN). Inherently, we know that materials having high-hydrogen content are very good space radiation shielding materials. Graded-Z material lay-ups are very good trapped electron mitigators for medium earth orbit (MEO) and geostationary earth orbit (GEO). In addition, secondary particles, namely neutrons, are produced as the primary particles penetrate a spacecraft, which can have deleterious effects to both humans and electronics. The use of "dopants," such as beryllium, boron, and lithium, impregnated in other shielding materials provides a means of absorbing the secondary neutrons. Several examples of optimized Graded-Z shielding layups that include the use of composite materials are presented and discussed in detail. This parametric shielding study is an extension of some earlier pioneering work we (William Atwell and Kristina Rojdev) performed in 20041 and 20092.

[The effectiveness of magnetic therapy of grade I-II radiation pneumofibrosis].

PubMed

Grushina, T I

2014-01-01

Radiation therapy of malignant tumours of the chest organs may result in radiation damage of the lungs. To prevent and reduce radiation-induced lung injuries, new types of radiation therapy have been developed, a number of various modifiers investigated, the methods of pharmacotherapy and physiotherapy proposed. The present study involved 37 patients presenting with radiation pneumofibrosis, including 7 ones with lung cancer and 30 patients with breast cancer. Based on the results of clinical, radiographic, and functional investigations, grade 1 and II pneumofibrosis was diagnosed in 20 and 17 patients respectively. After the application of an alternating magnetic field during 15 days, all the patients experience the overall regression of clinical symptoms and disorders of respiratory biomechanics. However, it seems premature to draw a definitive conclusion about the effectiveness of magnetic therapy of grade 1 and II radiation pneumofibrosis before the extensive in-depth investigations are carried out based on a large clinical material including the results of long-term follow-up studies and continuous monitoring.

Feasibility and radiation induced toxicity regarding the first application of transperineal implementation of biocompatible balloon for high dose radiotherapy in patients with prostate carcinoma

PubMed Central

2013-01-01

Objective To evaluate the feasibility of the transperineal implementation of biocompatible balloon (Prospace) and the acute toxicity of high dose 3DCRT in patients with localized low risk prostate cancer. Materials and methods Between December 2011 and April 2012, fifteen patients were treated with external 3DCRT consisted of 76–78 Gy in 38–39 daily fractions (2.0 Gy/ fraction). Before 3DCRT, we placed the Prospace though the perineum by a minimally invasive procedure in the intermediate space between the rectum and the prostate. The primary study endpoint was the evaluation of acute toxicity according to the EORTC/RTOG radiation toxicity scale. Erectile function was evaluated with the IIEF-5 questionnaire. Rectosigmoidoscopy was performed at baseline, at the end of 3DCRT and 3 months thereafter in order to assess also the rectal toxicity according to Subjective-RectoSigmoid (S-RS) scale. The evaluation of pain related to Prospace implementation was done with the visual analogue score (VAS). Results The acute toxicities were as follows: grade I GI toxicity in two patients and for GU toxicity, three patients with grade I of nocturia, four patients with grade I of frequency, two patients with grade I and two patients with grade II of dysouria. The mean score of rectal toxicity according to S-RS score was 1.8(±0.6). The mean VAS score related to Prospace was 1.4(±0.5). Erectile function was unchanged. The Prospace device was found stable in sequential CTs during irradiation. Conclusions The implementation of PROSPACE was feasible, while the acute radiation toxicity was low and comparable with IMRT techniques. PMID:23566526

Compound refractive X-ray lens

DOEpatents

Nygren, David R.; Cahn, Robert; Cederstrom, Bjorn; Danielsson, Mats; Vestlund, Jonas

2000-01-01

An apparatus and method for focusing X-rays. In one embodiment, his invention is a commercial-grade compound refractive X-ray lens. The commercial-grade compound refractive X-ray lens includes a volume of low-Z material. The volume of low-Z material has a first surface which is adapted to receive X-rays of commercially-applicable power emitted from a commercial-grade X-ray source. The volume of low-Z material also has a second surface from which emerge the X-rays of commercially-applicable power which were received at the first surface. Additionally, the commercial-grade compound refractive X-ray lens includes a plurality of openings which are disposed between the first surface and the second surface. The plurality of openings are oriented such that the X-rays of commercially-applicable power which are received at the first surface, pass through the volume of low-Z material and through the plurality openings. In so doing, the X-rays which emerge from the second surface are refracted to a focal point.

Optical materials for use with excimer lasers

NASA Astrophysics Data System (ADS)

Sedlacek, Jan H. C.; Rothschild, Mordechai

1993-04-01

Synthetic UV-grade fused silica, crystalline fluorides, and dielectric coatings have been evaluated for transparency and durability at 193 nm. Most bulk materials eventually develop color centers, and fused silica also changes its density and index of refraction. However, the rate at which these changes occur and their magnitude vary strongly with material, grade, and other more subtle details. Careful selection and possibly pretesting are recommended, in order to ensure optimal matching between the intended application and the material properties.

Novel Functionally Graded Thermal Barrier Coatings in Coal-Fired Power Plant Turbines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Jing

This project presents a detailed investigation of a novel functionally graded coating material, pyrochlore oxide, for thermal barrier coating (TBC) in gas turbines used in coal-fired power plants. Thermal barrier coatings are refractory materials deposited on gas turbine components, which provide thermal protection for metallic components at operating conditions. The ultimate goal of this research is to develop a manufacturing process to produce the novel low thermal conductivity and high thermal stability pyrochlore oxide based coatings with improved high-temperature durability. The current standard TBC, yttria stabilized zirconia (YSZ), has service temperatures limited to <1200°C, due to sintering and phase transitionmore » at higher temperatures. In contrast, pyrochlore oxide, e.g., lanthanum zirconate (La 2Zr 2O 7, LZ), has demonstrated lower thermal conductivity and better thermal stability, which are crucial to high temperature applications, such as gas turbines used in coal-fired power plants. Indiana University – Purdue University Indianapolis (IUPUI) has collaborated with Praxair Surface Technologies (PST), and Changwon National University in South Korea to perform the proposed research. The research findings are critical to the extension of current TBCs to a broader range of high-temperature materials and applications. Several tasks were originally proposed and accomplished, with additional new opportunities identified during the course of the project. In this report, a description of the project tasks, the main findings and conclusions are given. A list of publications and presentations resulted from this research is listed in the Appendix at the end of the report.« less

The effect of surface grain reversal on the AC losses of sintered Nd-Fe-B permanent magnets

NASA Astrophysics Data System (ADS)

Moore, Martina; Roth, Stefan; Gebert, Annett; Schultz, Ludwig; Gutfleisch, Oliver

2015-02-01

Sintered Nd-Fe-B magnets are exposed to AC magnetic fields in many applications, e.g. in permanent magnet electric motors. We have measured the AC losses of sintered Nd-Fe-B magnets in a closed circuit arrangement using AC fields with root mean square-values up to 80 mT (peak amplitude 113 mT) over the frequency range 50 to 1000 Hz. Two magnet grades with different dysprosium content were investigated. Around the remanence point the low grade material (1.7 wt% Dy) showed significant hysteresis losses; whereas the losses in the high grade material (8.9 wt% Dy) were dominated by classical eddy currents. Kerr microscopy images revealed that the hysteresis losses measured for the low grade magnet can be mainly ascribed to grains at the sample surface with multiple domains. This was further confirmed when the high grade material was subsequently exposed to DC and AC magnetic fields. Here a larger number of surface grains with multiple domains are also present once the step in the demagnetization curve attributed to the surface grain reversal is reached and a rise in the measured hysteresis losses is evident. If in the low grade material the operating point is slightly offset from the remanence point, such that zero field is not bypassed, its AC losses can also be fairly well described with classical eddy current theory.

Readability assessment of online patient education materials provided by the European Association of Urology.

PubMed

Betschart, Patrick; Zumstein, Valentin; Bentivoglio, Maico; Engeler, Daniel; Schmid, Hans-Peter; Abt, Dominik

2017-12-01

To assess the readability of the web-based patient education material provided by the European Association of Urology. English patient education materials (PEM) as available in May 2017 were obtained from the EAU website. Each topic was analyzed separately using six well-established readability assessment tools, including Flesch-Kincaid Grade Level (FKGL), SMOG Grade Level (SMOG), Coleman-Liau Index (CLI), Gunning Fog Index (GFI), Flesch Reading Ease Formula (FRE) and Fry Readability Graph (FRG). A total of 17 main topics were identified of which separate basic and in-depth information is provided for 14 topics. Calculation of grade levels (FKGL, SMOG, CLI, GFI) showed readability scores of 7th-13th grade for basic information, 8th-15th grade for in-depth information and 7th-15th grade for single PEM. Median FRE score was 54 points (range 45-65) for basic information and 56 points (41-64) for in-depth information. The FRG as a graphical assessment revealed only 13 valid results with an approximate 8th-17th grade level. The EAU provides carefully worked out PEM for 17 urological topics. Although improved readability compared to similar analyses was found, a simplification of certain chapters might be helpful to facilitate better patient understanding.

Social Science Curriculum Guide and Selected Multi-Media, 10-12.

ERIC Educational Resources Information Center

Gaydosh, Ronald

GRADES OR AGES: Grades 10-12. SUBJECT MATTER: Social science. ORGANIZATION AND PHYSICAL APPEARANCE: The extensive introductory material includes rationale, definitions of the social science core disciplines, glossary of terms, and descriptions of concepts. The course material includes political science, history, economics, geography, sociology,…

Small Schools Curriculum: Physical Education, K-6.

ERIC Educational Resources Information Center

Hartl, David, Ed.; Hartl, Doris, Ed.

The self-contained sections within the document (one for grades K-3, the other for grades 4-6) present objectives, activities, monitoring procedures and resources for the elementary physical education curriculum for Washington small school districts. Identical introductory materials describe the organization of Small Schools materials,…

Method of making a functionally graded material

DOEpatents

Lauf, Robert J.; Menchhofer, Paul A.; Walls, Claudia A.; Moorhead, Arthur J.

2002-01-01

A gelcasting method of making an internally graded article alternatively includes the steps of: preparing a slurry including a least two different phases suspended in a gelcasting solution, the phases characterized by having different settling characteristics; casting the slurry into a mold having a selected shape; allowing the slurry to stand for a sufficient period of time to permit desired gravitational fractionation in order to achieve a vertical compositional gradient in the molded slurry; gelling the slurry to form a solid gel while preserving the vertical compositional gradient in the molded slurry; drying the gel to form a dried green body; and sintering the dry green body to form a solid object, at least one property thereof varying along the vertical direction because of the compositional gradient in the molded slurry.

The effect of porosity and microcracking on the thermomechanical properties of cordierite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shyam, A.; Bruno, G.; Watkins, T. R.

2015-08-28

The effect of porosity and microcracking on the mechanical properties (strength, fracture toughness, Young’s modulus, and fracture energy) and thermal expansion of diesel particulate filter (DPF) grade cordierite materials has been investigated. A method to deconvolute the effect of porosity and microcracking on Young’s modulus is proposed. In addition, the microcrack density and the pore morphology factor are calculated by applying a micromechanical differential scheme. The values of the investigated mechanical properties are shown to decrease with an increase in porosity, but the thermal expansion values are insensitive to porosity. The variation in mechanical properties as a function of porositymore » leads to distinct porosity dependence of thermal shock resistance for crack initiation and crack propagation for DPF grade synthetic cordierite.« less

Assessment of Diastolic Function in Single Ventricle Patients Following the Fontan Procedure

PubMed Central

Margossian, Renee; Sleeper, Lynn A.; Pearson, Gail D.; Barker, Piers C.; Mertens, Luc; Quartermain, Michael D.; Su, Jason T.; Shirali, Girish; Chen, Shan; Colan, Steven D.

2016-01-01

Objectives Patients with functional single ventricles (FSV) following the Fontan procedure have abnormal cardiac mechanics. We sought to determine factors that influence diastolic function and to describe associations of diastolic function with current clinical status. Methods Echocardiograms were obtained as part of the Pediatric Heart Network Fontan Cross-Sectional Study. Diastolic function grade (DFG) was assessed as normal (grade 0), impaired relaxation (grade 1), pseudonormalization (grade 2), restrictive (grade 3). Studies were also classified dichotomously (restrictive pattern present or absent). Relationships between DFG and pre-Fontan variables (e.g., ventricular morphology, age at Fontan, history of volume-unloading surgery), and current status (e.g., systolic function, valvar regurgitation, exercise performance) were explored. Results DFG was calculable in 326/546 subjects (60%); mean age = 11.7±3.3 years. Overall, 32% of patients had grade 0, 9% grade 1, 37% grade 2, and 22% grade 3. Although there was no association between ventricular morphology and DFG, there was an association between ventricular morphology and E’, which was lowest in those with right ventricular morphology (p<.001); this association remained significant when using z-scores adjusted for age (p=<.001). DFG was associated with achieving maximal effort on exercise testing (p=.004); the majority (64%) of those not achieving maximal effort had DFG 2 or 3.No additional significant associations of DFG with laboratory or clinical measures were identified. Conclusion Assessment of diastolic function by current algorithms results in a high percentage of patients with abnormal DFG, but we found few clinically or statistically significant associations. This may imply a lack of impact of abnormal diastolic function upon clinical outcome in this cohort, or may indicate that the methodology may not be applicable to pediatric FSV patients. PMID:27624592

Microstructural Evolution and Constitutive Relationship of M350 Grade Maraging Steel During Hot Deformation

NASA Astrophysics Data System (ADS)

Chakravarthi, K. V. A.; Koundinya, N. T. B. N.; Narayana Murty, S. V. S.; Nageswara Rao, B.

2017-03-01

Maraging steels exhibit extraordinary strength coupled with toughness and are therefore materials of choice for critical structural applications in defense, aerospace and nuclear engineering. Thermo-mechanical processing is an important step in the manufacture of these structural components. This process assumes significance as these materials are expensive and the mechanical properties obtained depend on the microstructure evolved during thermo-mechanical processing. In the present study, M350 grade maraging steel specimens were hot isothermally compressed in the temperature range of 900-1200 °C and in the strain rate range of 0.001-100 s-1, and true stress-true strain curves were generated. The microstructural evolution as a function of strain rate and temperature in the deformed compression specimens was studied. The effect of friction between sample and compression dies was evaluated, and the same was found to be low. The measured flow stress data was used for the development of a constitutive model to represent the hot deformation behavior of this alloy. The proposed equation can be used as an input in the finite element analysis to obtain the flow stress at any given strain, strain rate, and temperature useful for predicting the flow localization or fracture during thermo-mechanical simulation. The activation energy for hot deformation was calculated and is found to be 370.88 kJ/mol, which is similar to that of M250 grade maraging steel.

A steady-state high-temperature apparatus for measuring thermal conductivity of ceramics

NASA Astrophysics Data System (ADS)

Filla, B. James

1997-07-01

A one-sided very-high-temperature guarded hot plate has been built to measure thermal conductivity of monolithic ceramics, ceramic composites, thermal barrier coatings, functional graded materials, and high-temperature metal alloys. It is an absolute, steady-state measurement device with an operational temperature range of 400-1400 K. Measurements are made in an atmosphere of low-pressure helium. Specimens examined in this apparatus are 70 mm in diameter, with thicknesses ranging between 1 and 8 mm. Optimal specimen thermal conductivities fall in the range of 0.5-30 W/(mK). Internal heated components are composed entirely of high-purity aluminum oxide, boron nitride, beryllium oxide, and fibrous alumina insulation board. Pure nickel and thermocouple-grade platinum-based alloys are the only metals used in the system. Apparatus design, modeling, and operation are described, along with the methods of data analysis that are unique to this system. An analysis of measurement uncertainty yields a combined measurement uncertainty of ±5%. Experimental measurements on several materials are presented to illustrate the precision and bias of the apparatus.

Low-grade oils and fats: effect of several impurities on biodiesel production over sulfonic acid heterogeneous catalysts.

PubMed

Morales, Gabriel; Bautista, L Fernando; Melero, Juan A; Iglesias, Jose; Sánchez-Vázquez, Rebeca

2011-10-01

Different lipidic wastes and low-grade oils and fats have been characterized and evaluated as feedstocks for the acid-catalyzed production of FAME. The characterization of these materials has revealed significant contents of free fatty acids, Na, K, Ca, Mg, P, unsaponifiable matter and humidity. Arenesulfonic acid-functionalized SBA-15 silica catalyst has provided yields to FAME close to 80% in the simultaneous esterification-transesterification of the different feedstocks, regardless of their nature and properties, using methanol under the following reaction conditions: 160 °C, 2 h, methanol to oil molar ratio of 30, 8 wt.% catalyst loading, and 2000 rpm stirring rate. Nevertheless, reutilization of the catalyst is compromised by high levels of impurities, especially because of deactivation by strong interaction of unsaponifiable matter with the catalytic sites. The conditioning of these materials by aqueous washing in the presence of cationic-exchange resin Amberlyst-15, followed by a drying step, resulted in a lower deactivation of the catalyst. Copyright © 2011 Elsevier Ltd. All rights reserved.

Processing, microstructure and mechanics of functionally graded Al A359/SiC(p) composite

NASA Astrophysics Data System (ADS)

Rodriguez-Castro, Ramon

2000-11-01

Metal matrix composites (MMCs) have great promise for high temperature, high strength, wear resistant applications. However, their brittleness has limited their use in load bearing applications. Functionally graded MMCs with a reinforcement concentration higher on the surface than in the interior offer new opportunities, as these materials will have high surface hardness as well as high resistance to crack growth towards the interior. In this dissertation the processing and mechanical properties of a functionally graded MMC are investigated. Rectangular blocks (100 mmx60 mmx50 mm) of functionally graded SiC particulate reinforced aluminum A359 matrix composite were prepared by centrifugal casting techniques. The reinforcement volume fraction profiles varied as the centrifugal force was applied, owing to the different densities of Al and SiC. The casting at 1300 rpm (angular velocity) had a well-mixed, refined microstructure with the maximum SiC volume fraction of 44% near the outer surface of the blocks. This surface exhibited an elevated hardness. The effect of SiC particulate reinforcement on strengthening of A359 Al alloy was experimentally studied by tensile testing specimens prepared from the cast blocks. There was a continuous increase in tensile and yield strength with increasing SiC volume fractions in the range of 0.20 to 0.30. On the contrary, there was a reduction in tensile and yield strength for SiC concentrations in the range of 0.30 to 0.40. The elasticity modulus increased with increasing SiC volume fractions in the whole reinforcement range (0.20--0.40). Fractographic analysis by SEM revealed a ductile failure process of void growth in the matrix, but the amount of the void growth was less when the SiC concentration was higher. SEM also revealed SiC reinforcement fracture and decohesion, with the particle fracture increasing with the particle concentration. Appropriate flat specimens with a continuously graded microstructure for fracture mechanics testing were machined from the cast blocks. No published work has reported specimens of similar characteristics (size of the specimens and continuous reinforcement gradation). Fracture mechanics of the composite specimens with the crack parallel to the gradation in elastic properties was studied to investigate the effect of the nonhomogeneous microstructure on fracture toughness. Fatigue pre-cracking was used and a limited amount of fatigue crack propagation data was gathered. Low values of DeltaKth and increased crack growth resistance in the Paris region were observed for the functionally graded composite compared to a homogeneous 20 vol% composite. R-curve (KR) behavior of fracture was investigated in the functionally graded composite. At elevated SiC concentrations (low values of crack length), limited dissipation of energy by restrained plastic deformation of the matrix at the crack tip produced low fracture toughness values. On the contrary, at longer crack lengths SiC content decreased and there was more absorption of energy, resulting in higher fracture toughness values. In addition, the crack growth resistance behavior of the FGM composite was compared to the corresponding behavior of an Al A359/SiCp 20 vol% homogeneous composite. The latter exhibited a declining KR-curve behavior whereas the FGM composite displayed an increasing KR-curve behavior. Consequently, this increasing crack growth resistance behavior displayed by the functionally graded Al A359/SiCp composite shows that tailored changes in the microstructure could circumvent the low toughness inherent in MMCs.

Characterization of Organic Materials in the Xenolithic Clasts in Sharps (H3.4) Meteorite Using Micro-Raman Spectroscopy

NASA Technical Reports Server (NTRS)

Chan, Q. H. S.; Zolensky, M. E.; Bodnar, R. J.; Kebukawa, Y.

2015-01-01

Graphitization of carbon is an irreversible process which alters the structure of graphitic materials in response to the increase in metamorphic grade (temperature and/or pressure). Carbonaceous materials offer a reliable geothermometer as their Raman spectra change systematically with increasing metamorphic grade. In this study, we identified carbonaceous materials in the xenolithic clasts in Sharps and interpreted their metamorphic history by revealing the structural organization (order) of the polyaromatic organic phases using micro-Raman spectroscopy.

Characterization of Organic Materials in the Xenolithic Clasts in Sharps (H3.4) Meteorite Using Microraman Spectroscopy

NASA Technical Reports Server (NTRS)

Chan, Q. H. S.; Zolensky, M. E.; Bodnar, R. J.; Kebukawa, Y.

2015-01-01

Graphitization of carbon is an irreversible process which alters the structure of graphitic materials in response to the increase in metamorphic grade (temperature and/or pressure). Carbonaceous materials offer a reliable geothermometer as their Raman spectra change systematically with increasing metamorphic grade [1-3]. In this study, we identified carbonaceous materials in the xenolithic clasts in Sharps and interpreted their metamorphic history by revealing the structural organization (order) of the polyaromatic organic phases using µ-Raman spectroscopy.

Acquisition of Mechanically Assisted Spark Plasma Sintering System for Advanced Research and Education on Functionally Graded Hybrid Materials

DTIC Science & Technology

2012-03-14

Institute. The proposed effort offers a multidisciplinary research program to achieve the topic goals by coupling thermal- acoustic - mechanical flight...optional optical pyrometer .  Single port for standard (mechanical vacuum pump) and high vacuum system. POWER SUPPLY  10,000 amp, 10 VDC pulsed...Amperage TEMPERATURE CONTROL SYSTEM  Ten (10) Type K and five (5) Type C thermocouples with protective flexible sheaths.  Optical Pyrometer

Adopt-A-Stream Teacher's Guide for Grades K-12.

ERIC Educational Resources Information Center

Georgia State Dept. of Natural Resources, Atlanta.

This guide comprises materials largely drawn from existing environmental education materials. The four major subject areas discussed mirror the Adopt-A Stream activities and include watersheds, nonpoint source pollution, and biological and chemical monitoring of stream conditions. The activities in this guide are grouped according to grade levels.…

7 CFR 58.331 - Starter distillate.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Quality Specifications for Raw Material § 58.331 Starter distillate. The refined flavor components when used to flavor butter and related products. It shall be of food grade quality, free of extraneous material and prepared in accordance with...

7 CFR 58.331 - Starter distillate.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Quality Specifications for Raw Material § 58.331 Starter distillate. The refined flavor components when used to flavor butter and related products. It shall be of food grade quality, free of extraneous material and prepared in accordance with...

Readability Levels of Second Grade Hi-Lo Reading Materials.

ERIC Educational Resources Information Center

Hllgendorff, Patricia H.

The revised Spache Readability Formula and the Fry Readability Formula were applied to 20 selected reading materials designed for adolescents reading at second grade level. Three samples from each text were examined. The results using the Spache formula corresponded to the publisher's stated readability levels, with no significant variability…

Patriotic Observances. Grades K-6.

ERIC Educational Resources Information Center

Manitoba Dept. of Education, Winnipeg.

Materials and suggestions to help teachers in grades K-6 highlight special dates that hold significance for Canadian children are provided. The purpose is to arouse an awareness in children of their Canadian identity. The "patriotic observances" should take place at the beginning of every school day. Materials concerning Canadian natural…

A Comparison of Programed Instruction with Conventional Methods for Teaching Two Units of Eighth Grade Science.

ERIC Educational Resources Information Center

Eshleman, Winston Hull

Compared were programed materials and conventional methods for teaching two units of eighth grade science. Programed materials used were linear programed books requiring constructed responses. The conventional methods included textbook study, written exercises, lectures, discussions, demonstrations, experiments, chalkboard drawings, films,…

Middle School Law Awareness Curriculum Guide, 1980.

ERIC Educational Resources Information Center

Seminole County Board of Public Instruction, Sanford, FL.

Materials, activities, and lesson plans for educating middle school students about the law and the legal system are presented. Materials for the sixth grade are contained in six sections: (1) Prehistoric Man; (2) Ancient Civilizations; (3) Ancient Greece; (4) Ancient Rome; (5) Medieval Civilizations; and (6) the Renaissance. Grade 7 has three…

Development of design guidelines for proper selection of graded aggregate base in Maryland state highways : [research summary].

DOT National Transportation Integrated Search

2015-01-01

Millions of tons of graded aggregate base (GAB) materials are used in construction of : highway base layers in Maryland due to their satisfactory mechanical properties. The : fines content of a GAB material is highly variable and is often related to ...

School Health Program. Interim Guide. Grade 9.

ERIC Educational Resources Information Center

Northwest Territories Dept. of Education, Yellowknife.

This interim guide, a component of the Northwest Territories (Canada) School Health Program, includes instructional strategies, lesson plans, reproducibles, and teacher background materials for ninth grade classes. The material is organized around the three curriculum units: (1) the mental and emotional well-being unit which has three lessons on…

New Concept Study for Repair of Bomb-Damaged Runways. Volume I. Concept Identification.

DTIC Science & Technology

1979-09-01

Expanded polystyrene beads would be pneumatically mixed with the cement to form a low density material. Initially, the ratio of foam to cement would...the combinations are presented with this concept. PRIMARY MATERIALS 0 Expanded polystyrene foam beads * Graded aggregate * Quick setting cement 61 E-4...probability of success - high ALTERNATE MATERIALS * Expanded polystyrene foam beads * Organic binders Furan Methyl Methacrylate Epoxy Aminos * Graded

Laser Micro and Nano Processing of Metals , Ceramics , and Polymers

NASA Astrophysics Data System (ADS)

Pfleging, Wilhelm; Kohler, Robert; Südmeyer, Isabelle; Rohde, Magnus

Laser -based material processing is well investigated for structuring , modification , and bonding of metals , ceramics , glasses, and polymers . Especially for material processing on micrometer, and nanometer scale laser-assisted processes will very likely become more prevalent as lasers offer more cost-effective solutions for advanced material research, and application. Laser ablation , and surface modification are suitable for direct patterning of materials and their surface properties. Lasers allow rapid prototyping and small-batch manufacturing . They can also be used to pattern moving substrates, permitting fly-processing of large areas at reasonable speed. Different types of laser processes such as ablation, modification, and welding can be successfully combined in order to enable a high grade of bulk and surface functionality. Ultraviolet lasers favored for precise and debris-free patterns can be generated without the need for masks, resist materials, or chemicals. Machining of materials, for faster operation, thermally driven laser processes using NIR and IR laser radiation, could be increasingly attractive for a real rapid manufacturing.

Possibilities for specific utilization of material properties for an optimal part design

NASA Astrophysics Data System (ADS)

Beier, T.; Gerlach, J.; Roettger, R.; Kuhn, P.

2017-09-01

High-strength, cold-formable steels offer great potential for meeting cost and safety requirements in the automotive industry. In view of strengths of up to 1200 MPa now attainable, certain aspects need to be analysed and evaluated in advance in the development process using these materials. In addition to early assessment of crash properties, it is also highly important to adapt the forming process to match the material potential. The steel making companies have widened their portfolios of cold-rolled dual-phase steels well beyond the conventional high-strength steels. There are added new grades which offer a customized selection of high energy absorption, deformation resistance or enhanced cold-forming properties. In this article the necessary components for material modelling for finite element simulation are discussed. Additionally the required tests for material model calibration are presented and the potentials of the thyssenkrupp Steel material data base are introduced. Besides classical tensile tests at different angles to rolling direction and the forming limit curve, the hydraulic bulge test is now available for a wide range of modern steel grades. Using the conventional DP-K®60/98 and the DP-K®700Y980T with higher yield strength the method for calibrating yield locus, hardening and formability is given. With reference to the examples of an A-pillar reinforcement and different crash tests the procedure is shown how the customer can evaluate an optimal steel grade for specific requirements. Although the investigated materials have different yield strengths, no large differences in the forming process between the two steel grades can be found. However some advantages of the high-yield grade can be detected in crash performance depending on the specific boundary and loading conditions.

Tunability of temperature dependent THz photonic band gaps in 1-D photonic crystals composed of graded index materials and semiconductor InSb

NASA Astrophysics Data System (ADS)

Singh, Bipin K.; Pandey, Praveen C.; Rastogi, Vipul

2018-05-01

Tunable temperature dependent terahertz photonic band gaps (PBGs) in one-dimensional (1-D) photonic crystal composed of alternating layers of graded index and semiconductor materials are demonstrated. Results show the influence of temperature, geometrical parameters, grading profile and material damping factor on the PBGs. Number of PBG increases with increasing the layer thickness and their bandwidth can be tuned with external temperature and grading parameters. Lower order band gap is more sensitive to the temperature which shows increasing trend with temperature, and higher order PBGs can also be tuned by controlling the external temperature. Band edges of PBGs are shifted toward higher frequency side with increasing the temperature. Results show that the operational frequencies of PBGs are unaffected when loss involved. This work enables to design tunable Temperature dependent terahertz photonic devices such as reflectors, sensors and filters etc.

How reliable is computerized assessment of readability?

PubMed

Mailloux, S L; Johnson, M E; Fisher, D G; Pettibone, T J

1995-01-01

To assess the consistency and comparability of readability software programs, four software programs (Corporate Voice, Grammatix IV, Microsoft Word for Windows, and RightWriter) were compared. Standard materials included 28 pieces of printed educational materials on human immunodeficiency virus/acquired immunodeficiency syndrome distributed nationally and the Gettysburg Address. Statistical analyses for the educational materials revealed that each of the three formulas assessed (Flesch-Kincaid, Flesch Reading Ease, and Gunning Fog Index) provided significantly different grade equivalent scores and that the Microsoft Word program provided significantly lower grade levels and was more inconsistent in the scores provided. For the Gettysburg Address, considerable variation was revealed among formulas, with the discrepancy being up to two grade levels. When averaging across formulas, there was a variation of 1.3 grade levels between the four software programs. Given the variation between formulas and programs, implications for decisions based on results of these software programs are provided.

Enhancing Teacher Performance in Spanish Elementary Classes. Volume Two: Translated Units. Final Report.

ERIC Educational Resources Information Center

Johansen, Barry-Craig P.; And Others

Spanish translations of 19 of the Minneapolis (Minnesota) Public Schools' elementary school science units are presented. The materials were translated for use in a partial immersion program. Unit topics include, among others: magnets, organisms (grade 1), seeds and plants (grade 1), butterflies (grade 2), electricity (grade 3), the food chain…

Power calculation of grading device in desintegrator

NASA Astrophysics Data System (ADS)

Bogdanov, V. S.; Semikopenko, I. A.; Vavilov, D. V.

2018-03-01

This article describes the analytical method of measuring the secondary power consumption, necessitated by the installation of a grading device in the peripheral part of the grinding chamber in the desintegrator. There is a calculation model for defining the power input of the disintegrator increased by the extra power demand, required to rotate the grading device and to grind the material in the area between the external row of hammers and the grading device. The work has determined the inertia moments of a cylindrical section of the grading device with armour plates. The processing capacity of the grading device is adjusted to the conveying capacity of the auger feeder. The grading device enables one to increase the concentration of particles in the peripheral part of the grinding chamber and the amount of interaction between particles and armour plates as well as the number of colliding particles. The perforated sections provide the output of the ground material with the proper size granules, which together with the effects of armour plates, improves the efficiency of grinding. The power demand to rotate the grading device does not exceed the admissible value.

Readability of Trauma-Related Patient Education Materials From the American Academy of Orthopaedic Surgeons.

PubMed

Eltorai, Adam E M; P Thomas, Nathan; Yang, Heejae; Daniels, Alan H; Born, Christopher T

2016-02-01

According to the american medical association (AMA) and the national institutes of health (NIH), the recommended readability of patient education materials should be no greater than a sixth-grade reading level. The online patient education information produced by the american academy of orthopaedic surgeons (AAOS) may be too complicated for some patients to understand. This study evaluated whether the AAOS's online trauma-related patient education materials meet recommended readability guidelines for medical information. Ninety-nine articles from the "Broken Bones and Injuries" section of the AAOS-produced patient education website, orthoinfo.org, were analyzed for grade level readability using the Flesch-Kincaid formula, a widely-used and validated tool to evaluate the text reading level. Results for each webpage were compared to the AMA/NIH recommended sixth-grade reading level and the average reading level of U.S. adults (eighth-grade). The mean (SD) grade level readability for all patient education articles was 8.8 (1.1). All but three of the articles had a readability score above the sixth-grade level. The readability of the articles exceeded this level by an average of 2.8 grade levels (95% confidence interval, 2.6 - 3.0; P < 0.0001). Furthermore, the average readability of the articles exceeded the average reading skill level of U.S. adults (eighth grade) by nearly an entire grade level (95% confidence interval, 0.6-1.0; P < 0.0001). The majority of the trauma-related articles from the AAOS patient education website have readability levels that may make comprehension difficult for a substantial portion of the patient population.

The Contribution of Executive Functions to Narrative Writing in Fourth Grade Children

ERIC Educational Resources Information Center

Drijbooms, Elise; Groen, Margriet A.; Verhoeven, Ludo

2015-01-01

The present study investigated the contribution of executive functions to narrative writing in fourth grade children, and evaluated to what extent executive functions contribute differentially to different levels of narrative composition. The written skills of 102 Dutch children in fourth grade were assessed using a narrative picture-elicitation…

Assessment of Liver Function in Patients With Hepatocellular Carcinoma: A New Evidence-Based Approach—The ALBI Grade

PubMed Central

Johnson, Philip J.; Berhane, Sarah; Kagebayashi, Chiaki; Satomura, Shinji; Teng, Mabel; Reeves, Helen L.; O'Beirne, James; Fox, Richard; Skowronska, Anna; Palmer, Daniel; Yeo, Winnie; Mo, Frankie; Lai, Paul; Iñarrairaegui, Mercedes; Chan, Stephen L.; Sangro, Bruno; Miksad, Rebecca; Tada, Toshifumi; Kumada, Takashi; Toyoda, Hidenori

2015-01-01

Purpose Most patients with hepatocellular carcinoma (HCC) have associated chronic liver disease, the severity of which is currently assessed by the Child-Pugh (C-P) grade. In this international collaboration, we identify objective measures of liver function/dysfunction that independently influence survival in patients with HCC and then combine these into a model that could be compared with the conventional C-P grade. Patients and Methods We developed a simple model to assess liver function, based on 1,313 patients with HCC of all stages from Japan, that involved only serum bilirubin and albumin levels. We then tested the model using similar cohorts from other geographical regions (n = 5,097) and other clinical situations (patients undergoing resection [n = 525] or sorafenib treatment for advanced HCC [n = 1,132]). The specificity of the model for liver (dys)function was tested in patients with chronic liver disease but without HCC (n = 501). Results The model, the Albumin-Bilirubin (ALBI) grade, performed at least as well as the C-P grade in all geographic regions. The majority of patients with HCC had C-P grade A disease at presentation, and within this C-P grade, ALBI revealed two classes with clearly different prognoses. Its utility in patients with chronic liver disease alone supported the contention that the ALBI grade was indeed an index of liver (dys)function. Conclusion The ALBI grade offers a simple, evidence-based, objective, and discriminatory method of assessing liver function in HCC that has been extensively tested in an international setting. This new model eliminates the need for subjective variables such as ascites and encephalopathy, a requirement in the conventional C-P grade. PMID:25512453

Comparative Readability Analysis of Online Patient Education Resources on Inflammatory Bowel Diseases.

PubMed

Gulati, Rishabh; Nawaz, Mohammad; Lam, Linh; Pyrsopoulos, Nikolaos T

2017-01-01

The National Institutes of Health recommend a readability grade level of less than 7th grade for patient directed information. In this study, we use validated readability metrics to analyze patient information from prominent websites pertaining to ulcerative colitis and Crohn's disease. The terms "Crohn's Disease," "Ulcerative Colitis," and "Inflammatory Bowel Disease" were queried on Google and Bing. Websites containing patient education material were saved as a text file and then modified through expungement of medical terminology that was described within the text. Modified text was then divided into subsections that were analyzed using six validated readability scales. None of the websites analyzed in this study achieved an estimated reading grade level below the recommended 7th grade. The median readability grade level (after modification) was 11.5 grade levels for both Crohn's disease and ulcerative colitis. The treatment subsection required the highest level of education with a median readability grade of 12th grade (range of 6.9 to 17). Readability of online patient education material from the analyzed popular websites far exceeds the recommended level of being less than 7th grade. Patient education resources should be revised to achieve wider health literacy.

An analysis of the readability characteristics of oral health information literature available to the public in Tasmania, Australia.

PubMed

Barnett, Tony; Hoang, Ha; Furlan, Ashlea

2016-03-17

The effectiveness of print-based health promotion materials is dependent on their readability. This study aimed to assess the characteristics of print-based oral health information literature publically available in Tasmania, Australia. Oral health education brochures were collected from 11 dental clinics across Tasmania and assessed for structure and format, content and readability. Reading level was calculated using three widely-used measures: Flesch-Kincaid Grade Level (FKGL), Flesch Reading Ease, and Simple Measure of Gobbledygook (SMOG) reading grade level. The FKGL of the 67 brochures sampled ranged from grade 3 to 13. The grade level for government health department brochures (n = 14) ranged from grade 4 to 11 (5.6 ± 1.8). Reading levels for materials produced by commercial sources (n = 22) ranged from 3 to 13 (8.3 ± 2.1), those from professional associations (n = 22) ranged from grade 7 to 11 (8.9 ± 0.9) and brochures produced by other sources (n = 9) ranged from 5 to 10 (7.6 ± 1.5). The SMOG test was positively correlated with the FKGL (rs = 0.92, p < 0.001) though consistently rated materials 2-3 grades higher. The reading level required to comprehend brochures published by government sources were, on average, lower than those from commercial, professional and other sources. Government materials were also more likely to contain fewer words and professional jargon terms than brochures from the other sources. A range of oral health information brochures were publically available for patients in both public and private dental clinics. However, their readability characteristics differed. Many brochures required a reading skill level higher than that suited to a large proportion of the Tasmanian population. Readability and other characteristics of oral health education materials should be assessed to ensure their suitability for use with patients, especially those suspected of having low literacy skills.

Improving the prediction of the final part geometry in high strength steels U drawing by means of advanced material and friction models

NASA Astrophysics Data System (ADS)

de Argandoña, Eneko Saenz; Mendiguren, Joseba; Otero, Irune; Mugarra, Endika; Otegi, Nagore; Galdos, Lander

2018-05-01

Steel has been used in vehicles from the automotive industry's inception. Different steel grades are continually being developed in order to satisfy new fuel economy requirements. For example, advanced high strength steel grades (AHSS) are widely used due to their good strength/weight ratio. Because each steel grade has a different microstructure composition and hardness, they show different behaviors when they are subjected to different strain paths. Similarly, the friction behavior when using different contact pressures is considerably altered. In the present paper, four different steel grades, ZSt380, DP600, DP780 and Fortiform 1050 materials are deeply characterized using uniaxial and cyclic tension-compression tests. Coefficient of friction (COF) is also obtained using strip drawing tests. These results have been used to calibrate mixed kinematic-hardening material models as well as pressure dependent friction models. Finally, the geometrical accuracy of the different material and friction models has been evaluated by comparing the numerical predictions with experimental demonstrators obtained using a U-Drawing tester.

Developing the Teaching Material Using ATV Cooperated with Student on Manufacturing Practice

NASA Astrophysics Data System (ADS)

Tsukamoto, Kimihide; Yamamoto, Keiichiro; Ueno, Takayuki; Imazato, Tatsunari; Sakamoto, Hidetoshi

Recently, a number of students have entered the college of technology with no experience of dismantling and assembling of even an easy machine (including toys) . It is necessary to study the correct usage of tools for lower grade students as a base of the technical education for dismantling and assembling of the machine. However, enough understanding has not been obtained though the usage of the tool is trained for first grade students. So, we executed the development on the teaching text and material of student practice curriculum, which is attractive subject of all-terrain vehicle [ATV]‧s dismantling and assembling for lower grade students. This practice make the student learn both how to use the tools and the steer mechanism of car through the dismantling and assembling of ATV. The text book and sub-teaching materials of this practice curriculum were created in cooperation with fifth grade students as graduation research. As a result, an effective teaching and learning text and sub-teaching materials in manufacturing practice could be developed from student‧s point of view.

Effect of concrete strength gradation to the compressive strength of graded concrete, a numerical approach

NASA Astrophysics Data System (ADS)

Pratama, M. Mirza Abdillah; Aylie, Han; Gan, Buntara Sthenly; Umniati, B. Sri; Risdanareni, Puput; Fauziyah, Shifa

2017-09-01

Concrete casting, compacting method, and characteristic of the concrete material determine the performance of concrete as building element due to the material uniformity issue. Previous studies show that gradation in strength exists on building member by nature and negatively influence the load carrying capacity of the member. A pilot research had modeled the concrete gradation in strength with controllable variable and observed that the weakest material determines the strength of graded concrete through uniaxial compressive loading test. This research intends to confirm the recent finding by a numerical approach with extensive variables of strength disparity. The finite element analysis was conducted using the Strand7 nonlinear program. The results displayed that the increase of strength disparity in graded concrete models leads to the slight reduction of models strength. A substantial difference in displacement response is encountered on the models for the small disparity of concrete strength. However, the higher strength of concrete mix in the graded concrete models contributes to the rise of material stiffness that provides a beneficial purpose for serviceability of building members.

Assessment of Online Patient Education Materials from Major Dermatologic Associations

PubMed Central

John, Ann M.; John, Elizabeth S.; Hansberry, David R.

2016-01-01

Objective: Patients increasingly use the internet to find medical information regarding their conditions and treatments. Physicians often supplement visits with written education materials. Online patient education materials from major dermatologic associations should be written at appropriate reading levels to optimize utility for patients. The purpose of this study is to assess online patient education materials from major dermatologic associations and determine if they are written at the fourth to sixth grade level recommended by the American Medical Association and National Institutes of Health. Design: This is a descriptive and correlational design. Setting: Academic institution. Participants/measurements: Patient education materials from eight major dermatology websites were downloaded and assessed using 10 readability scales. A one-way analysis of variance and Tukey’s Honestly Statistically Different post hoc analysis were performed to determine the difference in readability levels between websites. Results: Two hundred and sixty patient education materials were assessed. Collectively, patient education materials were written at a mean grade level of 11.13, with 65.8 percent of articles written above a tenth grade level and no articles written at the American Medical Association/National Institutes of Health recommended grade levels. Analysis of variance demonstrated a significant difference between websites for each reading scale (p<0.001), which was confirmed with Tukey’s Honestly Statistically Different post hoc analysis. Conclusion: Online patient education materials from major dermatologic association websites are written well above recommended reading levels. Associations should consider revising patient education materials to allow more effective patient comprehension. (J ClinAesthet Dermatol. 2016;9(9):23–28.) PMID:27878059

Assessment of Online Patient Education Materials from Major Dermatologic Associations.

PubMed

John, Ann M; John, Elizabeth S; Hansberry, David R; Lambert, William Clark

2016-09-01

Objective: Patients increasingly use the internet to find medical information regarding their conditions and treatments. Physicians often supplement visits with written education materials. Online patient education materials from major dermatologic associations should be written at appropriate reading levels to optimize utility for patients. The purpose of this study is to assess online patient education materials from major dermatologic associations and determine if they are written at the fourth to sixth grade level recommended by the American Medical Association and National Institutes of Health. Design: This is a descriptive and correlational design. Setting: Academic institution. Participants/measurements: Patient education materials from eight major dermatology websites were downloaded and assessed using 10 readability scales. A one-way analysis of variance and Tukey's Honestly Statistically Different post hoc analysis were performed to determine the difference in readability levels between websites. Results: Two hundred and sixty patient education materials were assessed. Collectively, patient education materials were written at a mean grade level of 11.13, with 65.8 percent of articles written above a tenth grade level and no articles written at the American Medical Association/National Institutes of Health recommended grade levels. Analysis of variance demonstrated a significant difference between websites for each reading scale (p<0.001), which was confirmed with Tukey's Honestly Statistically Different post hoc analysis. Conclusion: Online patient education materials from major dermatologic association websites are written well above recommended reading levels. Associations should consider revising patient education materials to allow more effective patient comprehension. (J ClinAesthet Dermatol. 2016;9(9):23-28.).

Electrostatic Separator for Beneficiation of Lunar Soil

NASA Technical Reports Server (NTRS)

Quinn, Jacqueline; Arens, Ellen; Trigwell, Steve; Captain, James

2010-01-01

A charge separator has been constructed for use in a lunar environment that will allow for separation of minerals from lunar soil. In the present experiments, whole lunar dust as received was used. The approach taken here was that beneficiation of ores into an industrial feedstock grade may be more efficient. Refinement or enrichment of specific minerals in the soil before it is chemically processed may be more desirable as it would reduce the size and energy requirements necessary to produce the virgin material, and it may significantly reduce the process complexity. The principle is that minerals of different composition and work function will charge differently when tribocharged against different materials, and hence be separated in an electric field.

Packing properties of starch-based powders under mild mechanical stress.

PubMed

Zanardi, I; Gabbrielli, A; Travagli, V

2009-07-01

This study reports the ability to settle of commercial pharmaceutical grade starch samples, both native and pregelatinized. The experiments were carried out under different relative humidity (RH%) conditions and the packing properties were evaluated using both official pharmacopoeial monograph conditions and also modified conditions in order to give a deeper knowledge of tapping under mild mechanical stress. The technique adopted, simulating common pharmaceutical operating practices, appears to be useful to estimate some technologically relevant features of diluent powder materials. Moreover, a general mathematical function has been applied to the experimental data; this could be appropriate for adequately describing material settling patterns and offers practical parameters for characterizing starch powders within the context of a pharmaceutical quality system.

Assessing the Readability of Online Information About Hip Arthroscopy.

PubMed

Mehta, Manish P; Swindell, Hasani W; Westermann, Robert W; Rosneck, James T; Lynch, T Sean

2018-04-06

To investigate the current readability of online information pertaining to hip arthroscopy. The terms "hip arthroscopy" and "hip scope" were entered into the advanced search functions of Google, Yahoo!, and Bing on March 25, 2017, and results from the first 3 pages were analyzed. Results were required to be unique, accessible websites with information about hip arthroscopy conveyed primarily via analyzable text. Two reviewers applied inclusion criteria to the initial 97 results, discussing to reach consensus in cases of disagreement. Overall, 60 unique results were reviewed with 48 meeting inclusion criteria. Websites were categorized as physician-sponsored, academic, commercial, governmental and nonprofit organization (NPO), or unspecified. Readability was measured via 6 different indices: the Flesch-Kincaid grade level (FKGL), Flesch Reading Ease (FRE), Gunning Fog Score, SMOG Index, Coleman-Liau Index (CLI), and Automated Readability Index (ARI) along with an average grade level and readability classification score. Forty-eight unique websites were assessed for readability, with physician-sponsored webpages composing the majority (47.92%) followed by academic sources (35.42%). The webpages' average grade level, incorporating information from all 6 metrics, was 12.79 ± 1.98. The current readability of online information pertaining to hip arthroscopy is at an inappropriately high reading level compared with the sixth-grade level recommended by the American Medical Association and National Institutes of Health, thus introducing significant barriers to understanding for many patients. Online materials should be edited to reduce word and sentence length and complexity, use simpler terms, and minimize use of passive voice to facilitate patient knowledge acquisition and understanding of online information about hip arthroscopy. This study shows that the current readability of online information on hip arthroscopy exceeds the suggested sixth-grade reading level. It also emphasizes the need for simplifying written materials and offers specific suggestions on doing so to increase accessibility of information for patients. Copyright © 2018 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Multifunctional organic thin films and their electronic/optical properties

NASA Astrophysics Data System (ADS)

Shao, Yan

The concept of multifunctional organic thin films and their electronic/optical properties has been applied to organic functional device design, fabrication, and characterization. The organic devices involve organic light-emitting diodes (OLEDs) and organic photovoltaic devices (OPV) in this dissertation. In the research of graded junction structure of OLEDs, two kinds of naturally-formed graded junction (NFGJ) structures, sharp and shallow graded junctions, can be formed using single thermal evaporation boat loaded with uniformly mixed charge transport and light-emitting materials. OLEDs with NFGJ have been demonstrated in Chapter 3; the performance is comparable to the heterojunction OLEDs, but with better device lifetime. A novel method to prepare highly uniform mixed organic solid solutions through a high temperature and high-pressure fusion process has been demonstrated in Chapter 4. A series of fused organic solid solution (FOSS) compounds with NPD doped with different organic emitting dopants were prepared and DSC technique was utilized to determine the thermal characteristics. For the first time, the schematic phase diagram for this binary system has been obtained. High performance OLEDs of single color and white emission were fabricated and the device properties were characterized. In Chapter 5, an efficient photovoltaic heterojunction of tetracene and fullerene has been investigated and high performance organic solar cells have been demonstrated by thermal deposition and successive heat treatment. The preliminary conclusion for this enhancement is discussed and supported by atomic force microscopy images, absorption spectra and x-ray diffraction analysis. Additionally, an effective organic photovoltaic heterojunction based on the typical triplet material PtOEP was demonstrated. It is believed that introducing appropriate organic materials with long exciton lifetime is a very promising way to improve photovoltaic performance.

The Application of materials attractiveness in a graded approach to nuclear materials security

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ebbinghaus, B.; Bathke, C.; Dalton, D.

2013-07-01

The threat from terrorist groups has recently received greater attention. In this paper, material quantity and material attractiveness are addressed through the lens of a minimum security strategy needed to prevent the construction of a nuclear explosive device (NED) by an adversary. Nuclear materials are placed into specific security categories (3 or 4 categories) , which define a number of security requirements to protect the material. Materials attractiveness can be divided into four attractiveness levels, High, Medium, Low, and Very Low that correspond to the utility of the material to the adversary and to a minimum security strategy that ismore » necessary to adequately protect the nuclear material. We propose a graded approach to materials attractiveness that recognizes for instance substantial differences in attractiveness between pure reactor-grade Pu oxide (High attractiveness) and fresh MOX fuel (Low attractiveness). In either case, an adversary's acquisition of a Category I quantity of plutonium would be a major incident, but the acquisition of Pu oxide by the adversary would be substantially worse than the acquisition of fresh MOX fuel because of the substantial differences in the time and complexity required of the adversary to process the material and fashion it into a NED.« less

Readability of Educational Materials to Support Parent Sexual Communication With Their Children and Adolescents.

PubMed

Ballonoff Suleiman, Ahna; Lin, Jessica S; Constantine, Norman A

2016-05-01

Sexual communication is a principal means of transmitting sexual values, expectations, and knowledge from parents to their children and adolescents. Many parents seek information and guidance to support talking with their children about sex and sexuality. Parent education materials can deliver this guidance but must use appropriate readability levels to facilitate comprehension and motivation. This study appraised the readability of educational materials to support parent sexual communication with their children. Fifty brochures, pamphlets, and booklets were analyzed using the Flesch-Kincaid, Gunning Fog, and Simple Measure of Gobbledygook (SMOG) index methods. Mean readability grade-level scores were 8.3 (range = 4.5-12.8), 9.7 (range = 5.5-14.9), and 10.1 (range = 6.7-13.9), respectively. Informed by National Institutes of Health-recommended 6th to 7th grade levels and American Medical Association-recommended 5th to 6th grade levels, percentages falling at or below the 7.0 grade level were calculated as 38%, 12%, and 2% and those falling at or below the 6.0 grade level were calculated as 12%, 2%, and 0% based on the Flesch-Kincaid, Gunning Fog, and SMOG methods, respectively. These analyses indicate that the majority of educational materials available online to support parents' communication with their children about sex and sexuality do not meet the needs of many or most parents. Efforts to improve the accessibility of these materials are warranted.

ROMI 3.1 Least-cost lumber grade mix solver using open source statistical software

Treesearch

Rebecca A. Buck; Urs Buehlmann; R. Edward Thomas

2010-01-01

The least-cost lumber grade mix solution has been a topic of interest to both industry and academia for many years due to its potential to help wood processing operations reduce costs. A least-cost lumber grade mix solver is a rough mill decision support system that describes the lumber grade or grade mix needed to minimize raw material or total production cost (raw...

Readability of patient education materials from the American Academy of Orthopaedic Surgeons and Pediatric Orthopaedic Society of North America web sites.

PubMed

Badarudeen, Sameer; Sabharwal, Sanjeev

2008-01-01

While experts recommend that the readability of patient education materials should be less than the sixth grade level, the available information pertaining to orthopaedic diseases may be excessively complex for some to read and comprehend. The Flesch-Kincaid grade level is the most widely used tool to evaluate the readability score of a given text, with a lower grade level suggesting easier readability. The goal of our study was to assess the readability of pediatric orthopaedic patient education materials that were developed by the American Academy of Orthopaedic Surgeons (AAOS) and the Pediatric Orthopaedic Society of North America (POSNA) and were accessible to the general public through the Internet. All articles from the "Children" section of the patient education library, "Your Orthopaedic Connection," on the AAOS web site and the "Parent/Patient" section on the POSNA web site were identified. The Flesch-Kincaid grade level of each article was determined with use of Microsoft Office Word software. The mean grade levels of articles that were available in 2001 were compared with those accessible in 2007. Fifty-seven unique articles were available in 2007 on both web sites compared with twenty-five articles available in 2001. The readability score of only one (2%) of the currently available articles was less than sixth grade level. The mean Flesch-Kincaid grade level of the currently available articles was 8.9 compared with 8.7 for the articles available in 2001 (p = 0.71). Our findings suggest that most of the pediatric orthopaedic patient education materials available on the AAOS and POSNA web sites have readability scores that may be too high, making comprehension difficult for a substantial portion of the United States population.

REORGANIZED SCIENCE CURRICULUM, 8, GRADE EIGHT SUPPLEMENT.

ERIC Educational Resources Information Center

Minneapolis Special School District 1, Minn.

THE FOURTEENTH IN A SERIES OF 17 VOLUMES, THIS VOLUME PROVIDES THE EIGHTH GRADE TEACHER WITH A GUIDE TO THE REORGANIZED SCIENCE CURRICULUM OF THE MINNEAPOLIS PUBLIC SCHOOLS. THE MATERIALS ARE AUGMENTED AND REVISED AS THE NEED ARISES. A CHART INDICATES CONCEPT BRIEF SUMMARY OF SUBJECT MATTER CONTENT FOR GRADE 8, AND A CHART OF THE GRADE CONTENT FOR…

South Carolina Word List, Grades 1-12. Basic Skills Assessment Program.

ERIC Educational Resources Information Center

Instructional Objectives Exchange, Los Angeles, CA.

Designed as a resource for reading teachers who are attempting to enhance their students' fundamental reading skills and to permit the more rigorous determination of readability levels for both instructional materials and testing devices, this word list provides a grade-by-grade set of key words students need to master for grades 1 through 12 The…

Tobacco Education Curriculum: Grade 3. Health Education: Substance Abuse Prevention.

ERIC Educational Resources Information Center

Mitchell, Christine K.; And Others

This teaching guide for a tobacco education curriculum at the third-grade level is a part of a coordinated K-12 educational support program for reducing smoking. It includes a tobacco curriculum matrix for grades K-12, sample teaching methods, concepts and objectives for grades K-3, and a resource materials list. The basic instructional concepts…

Tobacco Education Curriculum: Grade 1. Health Education: Substance Abuse Prevention.

ERIC Educational Resources Information Center

Mitchell, Christine K.; And Others

This teaching guide for a tobacco education curriculum at the first-grade level is a part of a coordinated K-12 educational support program for reducing smoking. It includes a tobacco curriculum matrix for grades K-12, sample teaching methods, concepts and objectives for grades K-3, and a resource materials list. The basic instructional concepts…

Tobacco Education Curriculum: Grade 6. Health Education: Substance Abuse Prevention.

ERIC Educational Resources Information Center

Mitchell, Christine K.; And Others

This teaching guide for a tobacco education curriculum at the sixth-grade level is a part of a coordinated K-12 educational support program for reducing smoking. It includes a tobacco curriculum matrix for grades K-12, sample teaching methods, concepts and objectives for grades 4-6, and a resource materials list. The basic instructional concepts…

Tobacco Education Curriculum: Grade 4. Health Education: Substance Abuse Prevention.

ERIC Educational Resources Information Center

Mitchell, Christine K.; And Others

This teaching guide for a tobacco education curriculum at the fourth grade level is part of a coordinated K-12 educational support program for reducing smoking. It includes a tobacco curriculum matrix for grades K-12, sample teaching methods, concepts and objectives for grades 4-6, and a resource materials list. The basic instructional concepts…

Language Arts Handbook for Primary Teachers in Multi-Graded Classrooms. South-Central Region.

ERIC Educational Resources Information Center

Manitoba Dept. of Education, Winnipeg.

This handbook presents materials designed to assist teachers in meeting the needs of primary school children in multi-graded classrooms. The handbook is divided into two parts. The first part consists of the following sections: (1) the multi-graded school; (2) strategies for multi-graded classrooms; (3) oracy--listening and speaking; (4) language…

Resolving Conflicts. Lawyers Helping Young People Become Good Citizens.

ERIC Educational Resources Information Center

American Bar Association, Chicago, IL. Special Committee on Youth Education for Citizenship.

Organized around the theme of conflict resolution, this booklet provides teachers and lawyers with classroom materials for elementary grades K-3 (Level A), intermediate grades 4-6 (Level B), middle school grades 6-8 (Level C), and high school grades 9-12 (Level D). In addition, each level contains pages for the lawyer (marked by the scales of…

7 CFR 52.1855 - Grades of Sultana raisins.

Code of Federal Regulations, 2010 CFR

2010-01-01

... § 52.1855 Grades of Sultana raisins. (a) “U.S. Grade A” is the quality of Sultana Raisins that have... in Table IV of this subpart. (b) “U.S. Grade B” is the quality of Sultana Raisins that have similar... than materially affected. Grit, sand, or silt None of any consequence may be present that affects the...

Development of a Novel Continuous Processing Technology for Functionally Graded Composite Energetic Materials Using an Inverse Design Procedure

DTIC Science & Technology

2006-01-01

is naturally suited to produce this type of gradient from one composition to another. Operating a twin screw extruder at one steady condition and...dynamically changing the ingredients to produce a new formulation will result in the extrudate changing from the original composition to second one...Because of the inherent backmixing in a twin screw extruder , an abrupt change in ingredients results in a more gradual change in the composition of

Analysis of Multiple Cracks in an Infinite Functionally Graded Plate

NASA Technical Reports Server (NTRS)

Shbeeb, N. I.; Binienda, W. K.; Kreider, K. L.

1999-01-01

A general methodology was constructed to develop the fundamental solution for a crack embedded in an infinite non-homogeneous material in which the shear modulus varies exponentially with the y coordinate. The fundamental solution was used to generate a solution to fully interactive multiple crack problems for stress intensity factors and strain energy release rates. Parametric studies were conducted for two crack configurations. The model displayed sensitivity to crack distance, relative angular orientation, and to the coefficient of nonhomogeneity.

Finite Element Analysis of Functionally Graded Material to Reduce Crazing in Transparent Armor

DTIC Science & Technology

2015-09-01

Constraints 3 Results 4 Tensile Pressure (psi) 4 Conclusions and Path Forward 5 References 7 Distribution List 9 FIGURES 1 Pressure plot 1 2 3D...Digimat unit cell and 2D plane strain model for ABAQUS 2 3 Control and FGM models 3 4 Boundary conditions 4 5 Pressure results (time = 23.47 µs) 4...6 Pressure results 1 5 7 Pressure results 2 5 UNCLASSIFIED Approved for public release; distribution is unlimited. 1 INTRODUCTION

FGM (Functionally Graded Material) Thermal Barrier Coatings for Hypersonic Structures - Design and Thermal Structural Analysis

DTIC Science & Technology

2007-06-29

than others. It was found that TZ-3Y-E, which is a partially stabilised zirconia powder , was particularly suitable. The percentage of ceramic powder...layered coatings The current ceramic powder that was being used was a fully stabilised zirconia powder TZ-0Y. However a readily available powder...TZ-3Y-E, partially stabilised zirconia powder , was available and utilised. These tests consisted of a combination of 3, 4 and 5 layers. In the

Readability, suitability, and health content assessment of web-based patient education materials on colorectal cancer screening.

PubMed

Tian, Chenlu; Champlin, Sara; Mackert, Michael; Lazard, Allison; Agrawal, Deepak

2014-08-01

Colorectal cancer (CRC) screening rates in the Unites States are still below target level. Web-based patient education materials are used by patients and providers to provide supplemental information on CRC screening. Low literacy levels and patient perceptions are significant barriers to screening. There are little data on the quality of these online materials from a health literacy standpoint or whether they address patients' perceptions. To evaluate the readability, suitability, and health content of web-based patient education materials on colon cancer screening. Descriptive study. Web-based patient materials. Twelve reputable and popular online patient education materials were evaluated. Readability was measured by using the Flesch-Kincaid Reading Grade Level, and suitability was determined by the Suitability Assessment of Materials, a scale that considers characteristics such as content, graphics, layout/typography, and learning stimulation. Health content was evaluated within the framework of the Health Belief Model, a behavioral model that relates patients' perceptions of susceptibility to disease, severity, and benefits and barriers to their medical decisions. Each material was scored independently by 3 reviewers. Flesch-Kincaid Reading Grade Level score, Suitability Assessment of Materials score, health content score. Readability for 10 of 12 materials surpassed the maximum recommended sixth-grade reading level. Five were 10th grade level and above. Only 1 of 12 materials received a superior suitability score; 3 materials received inadequate scores. Health content analysis revealed that only 50% of the resources discussed CRC risk in the general population and <25% specifically addressed patients at high risk, such as African Americans, smokers, patients with diabetes, and obese patients. For perceived barriers to screening, only 8.3% of resources discussed embarrassment, 25% discussed pain with colonoscopy, 25% addressed cost of colonoscopy, and none specifically mentioned the need to get colonoscopy when no symptoms are present. No material discussed the social benefits of screening. Descriptive design. Most online patient education materials for CRC screening are written beyond the recommended sixth-grade reading level, with suboptimal suitability. Health content is lacking in addressing key perceived risks, barriers, and benefits to CRC screening. Developing more appropriate and targeted patient education resources on CRC may improve patient understanding and promote screening. Copyright © 2014 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

Fabrication, Characterization and Modeling of Functionally Graded Materials

NASA Astrophysics Data System (ADS)

Lee, Po-Hua

In the past few decades, a number of theoretical and experimental studies for design, fabrication and performance analysis of solar panel systems (photovoltaic/thermal systems) have been documented. The existing literature shows that the use of solar energy provides a promising solution to alleviate the shortage of natural resources and the environmental pollution associated with electricity generation. A hybrid solar panel has been invented to integrate photovoltaic (PV) cells onto a substrate through a functionally graded material (FGM) with water tubes cast inside, through which water flow serves as both a heat sink and a solar heat collector. Due to the unique and graded material properties of FGMs, this novel design not only supplies efficient thermal harvest and electrical production, but also provides benefits such as structural integrity and material efficiency. In this work, a sedimentation method has been used to fabricate aluminum (Al) and high-density polyethylene (HDPE) FGMs. The size effect of aluminum powder on the material gradation along the depth direction is investigated. Aluminum powder or the mixture of Al and HDPE powder is thoroughly mixed and uniformly dispersed in ethanol and then subjected to sedimentation. During the sedimentation process, the concentration of Al and HDPE particles temporally and spatially changes in the depth direction due to the non-uniform motion of particles; this change further affects the effective viscosity of the suspension and thus changes the drag force of particles. A Stokes' law based model is developed to simulate the sedimentation process, demonstrate the effect of manufacturing parameters on sedimentation, and predict the graded microstructure of deposition in the depth direction. In order to improve the modeling for sedimentation behavior of particles, the Eshelby's equivalent inclusion method (EIM) is presented to determine the interaction between particles, which is not considered in a Stokes' law based model. This method is initially applied to study the case of one drop moving in a viscous fluid; the solution recovers the closed form classic solution when the drop is spherical. Moreover, this method is general and can be applied to the cases of different drop shapes and the interaction between multiple drops. The translation velocities of the drops depend on the relative position, the center-to-center distance of drops, the viscosity and size of drops. For the case of a pair of identical spherical drops, the present method using a linear approximation of the eigenstrain rate has provided a very close solution to the classic explicit solution. If a higher order of the polynomial form of the eigenstrain rate is used, one can expect a more accurate result. To meet the final goal of mass production of the aforementioned Al-HDPE FGM, a faster and more economical material manufacturing method is proposed through a vibration method. The particle segregation of larger aluminum particles embedded in the concentrated suspension of smaller high-density polyethylene is investigated under vibration with different frequencies and magnitudes. Altering experimental parameters including time and amplitude of vibration, the suspension exhibits different particle segregation patterns: uniform-like, graded and bi-layered. For material characterization, small cylinder films of Al-HDPE system FGM are obtained after the stages of dry, melt and solidification. Solar panel prototypes are fabricated and tested at different water flow rates and solar irradiation intensities. The temperature distribution in the solar panel is measured and simulated to evaluate the performance of the solar panel. Finite element simulation results are very consistent with the experimental data. The understanding of heat transfer in the hybrid solar panel prototypes gained through this study will provide a foundation for future solar panel design and optimization.

Readability of Spine-Related Patient Education Materials From Leading Orthopedic Academic Centers.

PubMed

Ryu, Justine H; Yi, Paul H

2016-05-01

Cross-sectional analysis of online spine-related patient education materials from leading academic centers. To assess the readability levels of spine surgery-related patient education materials available on the websites of academic orthopedic surgery departments. The Internet is becoming an increasingly popular resource for patient education. Yet many previous studies have found that Internet-based orthopedic-related patient education materials from subspecialty societies are written at a level too difficult for the average American; however, no prior study has assessed the readability of spine surgery-related patient educational materials from leading academic centers. All spine surgery-related articles from the online patient education libraries of the top five US News & World Report-ranked orthopedic institutions were assessed for readability using the Flesch-Kincaid (FK) readability test. Mean readability levels of articles amongst the five academic institutions and articles were compared. We also determined the number of articles with readability levels at or below the recommended sixth- or eight-grade levels. Intraobserver and interobserver reliability of readability assessment were assessed. A total of 122 articles were reviewed. The mean overall FK grade level was 11.4; the difference in mean FK grade level between each department varied significantly (range, 9.3-13.4; P < 0.0001). Twenty-three articles (18.9%) had a readability level at or below the eighth grade level, and only one (0.8%) was at or below the sixth grade level. Intraobserver and interobserver reliability were both excellent (intraclass correlation coefficient of 1 for both). Online patient education materials related to spine from academic orthopedic centers are written at a level too high for the average patient, consistent with spine surgery-related patient education materials provided by the American Academy of Orthopaedic Surgeons and spine subspecialty societies. This study highlights the potential difficulties patients might have in reading and comprehending the information in publicly available education materials related to spine. N/A.

The Ottawa panel clinical practice guidelines for the management of knee osteoarthritis. Part one: introduction, and mind-body exercise programs.

PubMed

Brosseau, Lucie; Taki, Jade; Desjardins, Brigit; Thevenot, Odette; Fransen, Marlene; Wells, George A; Imoto, Aline Mizusaki; Toupin-April, Karine; Westby, Marie; Gallardo, Inmaculada C Álvarez; Gifford, Wendy; Laferrière, Lucie; Rahman, Prinon; Loew, Laurianne; Angelis, Gino De; Cavallo, Sabrina; Shallwani, Shirin Mehdi; Aburub, Ala'; Bennell, Kim L; Van der Esch, Martin; Simic, Milena; McConnell, Sara; Harmer, Alison; Kenny, Glen P; Paterson, Gail; Regnaux, Jean-Philippe; Lefevre-Colau, Marie-Martine; McLean, Linda

2017-05-01

To identify effective mind-body exercise programs and provide clinicians and patients with updated, high-quality recommendations concerning non-traditional land-based exercises for knee osteoarthritis. A systematic search and adapted selection criteria included comparative controlled trials with mind-body exercise programs for patients with knee osteoarthritis. A panel of experts reached consensus on the recommendations using a Delphi survey. A hierarchical alphabetical grading system (A, B, C+, C, D, D+, D-) was used, based on statistical significance ( P < 0.5) and clinical importance (⩾15% improvement). The four high-quality studies identified demonstrated that various mind-body exercise programs are promising for improving the management of knee osteoarthritis. Hatha Yoga demonstrated significant improvement for pain relief (Grade B) and physical function (Grade C+). Tai Chi Qigong demonstrated significant improvement for quality of life (Grade B), pain relief (Grade C+) and physical function (Grade C+). Sun style Tai Chi gave significant improvement for pain relief (Grade B) and physical function (Grade B). Mind-body exercises are promising approaches to reduce pain, as well as to improve physical function and quality of life for individuals with knee osteoarthritis.

Readability of Written Materials for CKD Patients: A Systematic Review.

PubMed

Morony, Suzanne; Flynn, Michaela; McCaffery, Kirsten J; Jansen, Jesse; Webster, Angela C

2015-06-01

The "average" patient has a literacy level of US grade 8 (age 13-14 years), but this may be lower for people with chronic kidney disease (CKD). Current guidelines suggest that patient education materials should be pitched at a literacy level of around 5th grade (age 10-11 years). This study aims to evaluate the readability of written materials targeted at patients with CKD. Systematic review. Patient information materials aimed at adults with CKD and written in English. Patient education materials designed to be printed and read, sourced from practices in Australia and online at all known websites run by relevant international CKD organizations during March 2014. Quantitative analysis of readability using Lexile Analyzer and Flesch-Kincaid tools. We analyzed 80 materials. Both Lexile Analyzer and Flesch-Kincaid analyses suggested that most materials required a minimum of grade 9 (age 14-15 years) schooling to read them. Only 5% of materials were pitched at the recommended level (grade 5). Readability formulas have inherent limitations and do not account for visual information. We did not consider other media through which patients with CKD may access information. Although the study covered materials from the United States, United Kingdom, and Australia, all non-Internet materials were sourced locally, and it is possible that some international paper-based materials were missed. Generalizability may be limited due to exclusion of non-English materials. These findings suggest that patient information materials aimed at patients with CKD are pitched above the average patient's literacy level. This issue is compounded by cognitive decline in patients with CKD, who may have lower literacy than the average patient. It suggests that information providers need to consider their audience more carefully when preparing patient information materials, including user testing with a low-literacy patient population. Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Factors predicting sensory and motor recovery after the repair of upper limb peripheral nerve injuries

PubMed Central

He, Bo; Zhu, Zhaowei; Zhu, Qingtang; Zhou, Xiang; Zheng, Canbin; Li, Pengliang; Zhu, Shuang; Liu, Xiaolin; Zhu, Jiakai

2014-01-01

OBJECTIVE: To investigate the factors associated with sensory and motor recovery after the repair of upper limb peripheral nerve injuries. DATA SOURCES: The online PubMed database was searched for English articles describing outcomes after the repair of median, ulnar, radial, and digital nerve injuries in humans with a publication date between 1 January 1990 and 16 February 2011. STUDY SELECTION: The following types of article were selected: (1) clinical trials describing the repair of median, ulnar, radial, and digital nerve injuries published in English; and (2) studies that reported sufficient patient information, including age, mechanism of injury, nerve injured, injury location, defect length, repair time, repair method, and repair materials. SPSS 13.0 software was used to perform univariate and multivariate logistic regression analyses and to investigate the patient and intervention factors associated with outcomes. MAIN OUTCOME MEASURES: Sensory function was assessed using the Mackinnon-Dellon scale and motor function was assessed using the manual muscle test. Satisfactory motor recovery was defined as grade M4 or M5, and satisfactory sensory recovery was defined as grade S3+ or S4. RESULTS: Seventy-one articles were included in this study. Univariate and multivariate logistic regression analyses showed that repair time, repair materials, and nerve injured were independent predictors of outcome after the repair of nerve injuries (P < 0.05), and that the nerve injured was the main factor affecting the rate of good to excellent recovery. CONCLUSION: Predictors of outcome after the repair of peripheral nerve injuries include age, gender, repair time, repair materials, nerve injured, defect length, and duration of follow-up. PMID:25206870

Demonstration and Validation of Stainless Steel Materials for Critical Above Grade Piping in Highly Corrosive Locations

DTIC Science & Technology

2017-05-01

Protecting And Bonding Reinforcing Steel In Cement -Based Composites, Corrosion 2009, Atlanta, GA, 22-26 March 2009. 7. Hock, V., O. Marshall, S...ER D C/ CE RL T R- 17 -1 3 DoD Corrosion Prevention and Control Program Demonstration and Validation of Stainless Steel Materials for...ERDC/CERL TR-17-13 May 2017 Demonstration and Validation of Stainless Steel Materials for Critical Above-Grade Piping in Highly Corrosive

Readability of arthroscopy-related patient education materials from the American Academy of Orthopaedic Surgeons and Arthroscopy Association of North America Web sites.

PubMed

Yi, Paul H; Ganta, Abhishek; Hussein, Khalil I; Frank, Rachel M; Jawa, Andrew

2013-06-01

We sought to assess the readability levels of arthroscopy-related patient education materials available on the Web sites of the American Academy of Orthopaedic Surgeons (AAOS) and the Arthroscopy Association of North America (AANA). We identified all articles related to arthroscopy available in 2012 from the online patient education libraries of AAOS and AANA. After performing follow-up editing, we assessed each article with the Flesch-Kincaid (FK) readability test. Mean readability levels of the articles from the AAOS Web site and the AANA Web site were compared. We also determined the number of articles with readability levels at or below the eighth-grade level (the average reading ability of the US adult population) and sixth-grade level (the widely recommended level for patient education materials). Intraobserver reliability and interobserver reliability of FK grade assessment were evaluated. A total of 62 articles were reviewed (43 from AAOS and 19 from AANA). The mean overall FK grade level was 10.2 (range, 5.2 to 12). The AAOS articles had a mean FK grade level of 9.6 (range, 5.2 to 12), whereas the AANA articles had a mean FK grade level of 11.4 (range, 8.7 to 12); the difference was significant (P < .0001). Only 3 articles had a readability level at or below the eighth-grade level and only 1 was at or below the sixth-grade level; all were from AAOS. Intraobserver reliability and interobserver reliability were excellent (intraclass correlation coefficient of 1 for both). Online patient education materials related to arthroscopy from AAOS and AANA may be written at a level too difficult for a large portion of the patient population to comprehend. Copyright © 2013 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Vibration analysis of rotating functionally graded Timoshenko microbeam based on modified couple stress theory under different temperature distributions

NASA Astrophysics Data System (ADS)

Ghadiri, Majid; Shafiei, Navvab

2016-04-01

In this study, thermal vibration of rotary functionally graded Timoshenko microbeam has been analyzed based on modified couple stress theory considering temperature change in four types of temperature distribution on thermal environment. Material properties of FG microbeam are supposed to be temperature dependent and vary continuously along the thickness according to the power-law form. The axial forces are also included in the model as the thermal and true spatial variation due to the rotation. Governing equations and boundary conditions have been derived by employing Hamiltonian's principle. The differential quadrature method is employed to solve the governing equations for cantilever and propped cantilever boundary conditions. Validations are done by comparing available literatures and obtained results which indicate accuracy of applied method. Results represent effects of temperature changes, different boundary conditions, nondimensional angular velocity, length scale parameter, different boundary conditions, FG index and beam thickness on fundamental, second and third nondimensional frequencies. Results determine critical values of temperature changes and other essential parameters which can be applicable to design micromachines like micromotor and microturbine.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Won, Yoo Jai; Ki, Hyungson

A novel picosecond-laser pulsed laser deposition method has been developed for fabricating functionally graded films with pre-designed gradient profiles. Theoretically, the developed method is capable of precisely fabricating films with any thicknesses and any gradient profiles by controlling the laser beam powers for the two different targets based on the film composition profiles. As an implementation example, we have successfully constructed functionally graded diamond-like carbon films with six different gradient profiles: linear, quadratic, cubic, square root, cubic root, and sinusoidal. Energy dispersive X-ray spectroscopy is employed for investigating the chemical composition along the thickness of the film, and the depositionmore » profile and thickness errors are found to be less than 3% and 1.04%, respectively. To the best of the authors' knowledge, this is the first method for fabricating films with designed gradient profiles and has huge potential in many areas of coatings and films, including multifunctional optical films. We believe that this method is not only limited to the example considered in this study, but also can be applied to all material combinations as long as they can be deposited using the pulsed laser deposition technique.« less

United States History: Colonization through Reconstruction. A Curriculum Guide for Grade 7.

ERIC Educational Resources Information Center

Hughes, Wayne; And Others

This curriculum guide of seventh grade materials for United States history, colonization through reconstruction, is prepared for the Carroll County Public Schools. Learning activities of the units are based on material available in the Carroll County Schools. The purpose of the program is to have students discover meaning and relevance in the…

The pallet industry: a changing hardwood market

Treesearch

G.P. Dempsey; D.G. Martens

1991-01-01

From its inception during World War II, the wooden pallet industry has grown to become the Nation's largest industrial consumer of hardwood lumber products. Since most of the raw material in wooden pallets is lower grade lumber, the pallet industry's growth, efficiency, and changing raw material inputs must be of concern to the grade hardwood lumber industry...

Improving the Precollegiate Curriculum on Latin America, Grades 6-12. Final Performance Report.

ERIC Educational Resources Information Center

Wirth, John D.

The Latin America Project, which developed print and nonprint materials for use in grades 6-12, is described. The two-year effort was conducted in five phases: survey of existing materials; the development of curriculum units; review of curriculum by teachers attending summer institutes; field testing and evaluation; and dissemination. Titles of…

Improving Student Science Achievement in Grades 4-6 through Hands-On Materials and Concept Verbalization.

ERIC Educational Resources Information Center

Brooks, Roger C.

This report describes a program designed to improve science achievement among students in grades 4-6 in a New Hampshire school. The areas of improvement included physical, earth, and life sciences. Analysis of the problem indicated a need for improved teaching techniques and for additional materials related to the instructional strategies. The…

AN ANALYSIS OF EIGHT DIFFERENT READING INSTRUCTIONAL METHODS USED WITH FIRST GRADE STUDENTS.

ERIC Educational Resources Information Center

CAMPBELL, PAUL B.; AND OTHERS

DURING THE SCHOOL YEAR 1965-66, GROUPS OF FIRST-GRADE PUPILS IN THE LIVONIA SCHOOL SYSTEM, MICHIGAN, WERE PROVIDED WITH READING INSTRUCTION MATERIALS FROM EIGHT PUBLISHERS REPRESENTING EIGHT APPROACHES AS PART ONE OF A 2-YEAR STUDY. THE MATERIALS WERE THE LIPPINCOTT BASIC READING SERIES, THE SCIENCE RESEARCH ASSOCIATES BASIC READING SERIES, THE…

THE NEGRO IN SCHOOLROOM LITERATURE, RESOURCE MATERIALS FOR THE TEACHER OF KINDERGARTEN THROUGH THE SIXTH GRADE. 2D ED.

ERIC Educational Resources Information Center

KOBLITZ, MINNIE W.

THIS ANNOTATED BIBLIOGRAPHY LISTS MORE THAN 250 BOOKS, CURRENT TO SEPTEMBER 1, 1966, WHICH CONTRIBUTE TO THE UNDERSTANDING AND APPRECIATION OF THE NEGRO HERITAGE. THESE RESOURCE MATERIALS, SUITABLE FOR STUDENTS IN KINDERGARTEN THROUGH SIXTH GRADE, ARE ARRANGED ACCORDING TO READING LEVEL. THERE ARE SECTIONS CONTAINING ADDITIONAL SOURCE MATERIALS…

The Hawaiian Monarchy: Instructional Materials/Resources for Grade 7 Social Studies. Draft.

ERIC Educational Resources Information Center

Hawaii State Dept. of Education, Honolulu. Office of Instructional Services.

Materials in this curriculum guide for a seventh grade social studies course focus on the development of the monarchy period in Hawaii's history. Following a course outline, 10 study units cover map skills, early historical background, and the reigns of the following kings and queens: Kamehameha, Liholiho, Kauikeaouli, Alexander Liholiho, Lot,…

Art Teaching Guides: Painting. Kindergarten-Grade 6. Curriculum Bulletin. No. 8 g. 1968-69 Series.

ERIC Educational Resources Information Center

New York City Board of Education, Brooklyn, NY. Div. of Curriculum and Instruction.

Growth in painting ability is dependent on frequent painting experiences, on thoughtful motivation, and on proper guidance and evaluation of progress. This guide includes materials and equipment, motivation, guidance procedures, activities, and evaluation for each grade level. A working space with materials and equipment in the classroom needs to…

Independent Reading in the Sixth Grade: Free Choice and Access to Material.

ERIC Educational Resources Information Center

Coy-Shaffer, Joye; Pettit, Shirley

A study conducted in the Orange County Public Schools in central Florida investigated the reading interests of sixth-grade students. The study also gathered information from teachers regarding the nature and source of reading materials used for independent reading in their classrooms and on the implementation of sustained silent reading practices.…

Electromagnetic Spectrum. 7th and 8th Grade Agriculture Science Curriculum. Teacher Materials.

ERIC Educational Resources Information Center

Southern Illinois Univ., Carbondale. Dept. of Agricultural Education and Mechanization.

This curriculum guide, the second in a set of six, contains teacher and student materials for a unit on the electromagnetic spectrum prepared as part of a seventh- and eighth-grade agricultural science curriculum that is integrated with science instruction. The guide contains the state goals and sample learning objectives for each goal for…

Sidewall tensiometer and method of determining soil moisture potential in below-grade earthen soil

DOEpatents

Hubbell, Joel M.; Sisson, James B.

2001-01-01

A sidewall tensiometer to in situ determine below-grade soil moisture potential of earthen soil includes, a) a body adapted for insertion into an opening in earthen soil below grade, the body having lateral sidewalls; b) a laterally oriented porous material provided relative to the body lateral sidewalls, the laterally oriented porous material at least in part defining a fluid chamber within the body; c) a pressure a sensor in fluid communication with the fluid chamber; and d) sidewall engaging means for engaging a portion of a sidewall of an earth opening to laterally urge the porous material into hydraulic communication with earthen soil of another portion of the opening sidewall. Methods of taking tensiometric measurements are also disclosed.

Readability of patient education materials in ophthalmology: a single-institution study and systematic review.

PubMed

Williams, Andrew M; Muir, Kelly W; Rosdahl, Jullia A

2016-08-03

Patient education materials should be written at a level that is understandable for patients with low health literacy. The aims of this study are (1) to review the literature on readability of ophthalmic patient education materials and (2) to evaluate and revise our institution's patient education materials about glaucoma using evidence-based guidelines on writing for patients with low health literacy. A systematic search was conducted on the PubMed/MEDLINE database for studies that have evaluated readability level of ophthalmic patient education materials, and the reported readability scores were assessed. Additionally, we collected evidence-based guidelines for writing easy-to-read patient education materials, and these recommendations were applied to revise 12 patient education handouts on various glaucoma topics at our institution. Readability measures, including Flesch-Kincaid Grade Level (FKGL), and word count were calculated for the original and revised documents. The original and revised versions of the handouts were then scored in random order by two glaucoma specialists using the Suitability Assessment of Materials (SAM) instrument, a grading scale used to evaluate suitability of health information materials for patients. Paired t test was used to analyze changes in readability measures, word count, and SAM score between original and revised handouts. Finally, five glaucoma patients were interviewed to discuss the revised materials, and patient feedback was analyzed qualitatively. Our literature search included 13 studies that evaluated a total of 950 educational materials. Among the mean FKGL readability scores reported in these studies, the median was 11 (representing an eleventh-grade reading level). At our institution, handouts' readability averaged a tenth-grade reading level (FKGL = 10.0 ± 1.6), but revising the handouts improved their readability to a sixth-grade reading level (FKGL = 6.4 ± 1.2) (p < 0.001). Additionally, the mean SAM score of our institution's handouts improved from 60 ± 7 % (adequate) for the original versions to 88 ± 4 % (superior) for the revised handouts (p < 0.001). Our systematic review of the literature reveals that ophthalmic patient education materials are consistently written at a level that is too high for many patients to understand. Our institution's experience suggests that applying guidelines on writing easy-to-understand material can improve the readability and suitability of educational materials for patients with low health literacy.

Optimum Material Composition for Minimizing the Stress Intensity Factor of Edge Crack in Thick-Walled FGM Circular Pipes Under Thermomechanical Loading

NASA Astrophysics Data System (ADS)

Sekine, Hideki; Yoshida, Kimiaki

This paper deals with the optimization problem of material composition for minimizing the stress intensity factor of radial edge crack in thick-walled functionally graded material (FGM) circular pipes under steady-state thermomechanical loading. Homogenizing the FGM circular pipes by simulating the inhomogeneity of thermal conductivity by a distribution of equivalent eigentemperature gradient and the inhomogeneity of Young's modulus and Poisson's ratio by a distribution of equivalent eigenstrain, we present an approximation method to obtain the stress intensity factor of radial edge crack in the FGM circular pipes. The optimum material composition for minimizing the stress intensity factor of radial edge crack is determined using a nonlinear mathematical programming method. Numerical results obtained for a thick-walled TiC/Al2O3 FGM circular pipe reveal that it is possible to decrease remarkably the stress intensity factor of radial edge crack by setting the optimum material composition profile.

Revisions of the Learning Mastery Systems for the Harper and Row Grades One and Two and the Macmillan Bank Street Grade One Reading Series.

ERIC Educational Resources Information Center

Maeder, Jacqueline; And Others

The revisions on the Learning Mastery Systems (LMSs) for the Harper & Row grade-one and grade-two and the Macmillan Bank Street grade-one reading programs are outlined in this document. A rationale for the revisions is presented. An LMS is a set of materials and procedures prepared by the southwest Regional Laboratory (SWRL) as an…

A Computer Vision System for Automated Grading of Rough Hardwood Lumber Using a Knowledge-Based Approach

Treesearch

Tai-Hoon Cho; Richard W. Conners; Philip A. Araman

1990-01-01

A sawmill cuts logs into lumber and sells this lumber to secondary remanufacturers. The price a sawmiller can charge for a volume of lumber depends on its grade. For a number of species the price of a given volume of material can double in going from one grade to the next higher grade. Thus, accurately establishing the grade of a volume of hardwood lumber is very...

Preparation and Ablating Behavior of FGM used in a Heat Flux Rocket Engine

NASA Astrophysics Data System (ADS)

He, Xiaodong; Han, Jiecai; Zhang, Xinghong

2002-01-01

Functionally Graded Material (FGM) is a new kind of nonhomogeneous materials, which composition varies gradually and continuously from metals to ceramics, thus excellence of both ceramic and metal is brought fully into play. The impetus for the development of FGM was to make thermal barrier materials for space shuttles and structure such as combustion chamber, gas vane, air vane, nose cone, fuel valve sheets and piston crown. There are several main techniques for making FGMs including chemical vapor deposition (CVD), powder metallurgy, plasma spraying and self-propagating high temperate synthesis (SHS). SHS Technology is the process by which condensed phases are produced by self - sustaining exothermic chemical reaction. Demonstrated advantages of SHS as a method for the preparation of materials include higher purity of the products, low energy requirements, and the relative simplicity of the process. SHS is particularly well suited to fabricating FGM. Due to the rapidity of the combustion reaction, the initial arrangement of the constituent in the green body is unchanged during combustion. In this paper, TiB2-Cu FGM and homogeneous cermets have been prepared by combing forced compaction with SHS. The experimental results show that process parameters significantly influence the combustion synthesis procedure of Ti-B-Cu system. Optimal process parameters have been gained for preparing TiB2-Cu FGM and cermets. TiB2-Cu FGM by SHS has a continuous distribution in microstructure along its thickness. The macroscopic interface of ceramic/metal joint is elemented. Mechanical properties of TiB2-Cu cermets were investigated at room and high temperature. The thermal stress of TiC-Ni FGM prepared by SHS are simulated at working condition, as well as comparing with a layered TiB2-Cu Non- FGM. Obviously, the TiB2-Cu FGM has the function of distortion and thermal stress relation. TiB2-Cu FGM was tested in the limited wind tunnel simulating the real condition of the heat flux rocket engine. As a result, TiB2-Cu FGM showed excellent resistant ablating properties. There is only a little loss of the mass after heated for 40 seconds in the wind tunnel. Meanwhile no cracks and breakup appeared in the FGM under the sharp thermal shock condition. Key words: functionally graded materials, combustion synthesis, ablation, thermal shock, thermal stress

Computer simulation of the pneumatic separator in the pneumatic-electrostatic separation system for recycling waste printed circuit boards with electronic components.

PubMed

Xue, Mianqiang; Xu, Zhenming

2013-05-07

Technologies could be integrated in different ways into automatic recycling lines for a certain kind of electronic waste according to practical requirements. In this study, a new kind of pneumatic separator with openings at the dust hooper was applied combing with electrostatic separation for recycling waste printed circuit boards. However, the flow pattern and the particles' movement behavior could not be obtained by experimental methods. To better control the separation quantity and the material size distribution, computational fluid dynamics was used to model the new pneumatic separator giving a detailed understanding of the mechanisms. Simulated results showed that the tangential velocity direction reversed with a relatively small value. Axial velocity exhibited two sharp decreases at the x axis. It is indicated that the bottom openings at the dust hopper resulted in an enormous change in the velocity profile. A new phenomenon that was named dusting was observed, which would mitigate the effect of particles with small diameter on the following electrostatic separation and avoid materials plugging caused by the waste printed circuit boards special properties effectively. The trapped materials were divided into seven grades. Experimental results showed that the mass fraction of grade 5, grade 6, and grade 7 materials were 27.54%, 15.23%, and 17.38%, respectively. Grade 1 particles' mass fraction was reduced by 80.30% compared with a traditional separator. Furthermore, the monocrystalline silicon content in silicon element in particles with a diameter of -0.091 mm was 18.9%, higher than that in the mixed materials. This study could serve as guidance for the future material flow control, automation control, waste recycling, and semiconductor storage medium destruction.

The Ottawa panel clinical practice guidelines for the management of knee osteoarthritis. Part two: strengthening exercise programs.

PubMed

Brosseau, Lucie; Taki, Jade; Desjardins, Brigit; Thevenot, Odette; Fransen, Marlene; Wells, George A; Mizusaki Imoto, Aline; Toupin-April, Karine; Westby, Marie; Álvarez Gallardo, Inmaculada C; Gifford, Wendy; Laferrière, Lucie; Rahman, Prinon; Loew, Laurianne; De Angelis, Gino; Cavallo, Sabrina; Shallwani, Shirin Mehdi; Aburub, Ala'; Bennell, Kim L; Van der Esch, Martin; Simic, Milena; McConnell, Sara; Harmer, Alison; Kenny, Glen P; Paterson, Gail; Regnaux, Jean-Philippe; Lefevre-Colau, Marie-Martine; McLean, Linda

2017-05-01

To identify effective strengthening exercise programs and provide rehabilitation teams and patients with updated, high-quality recommendations concerning traditional land-based exercises for knee osteoarthritis. A systematic search and adapted selection criteria included comparative controlled trials with strengthening exercise programs for patients with knee osteoarthritis. A panel of experts reached consensus on the recommendations using a Delphi survey. A hierarchical alphabetical grading system (A, B, C+, C, D, D+ or D-) was based on statistical significance ( p < 0.5) and clinical importance (⩾15% improvement). The 26 high-quality studies identified demonstrated that various strengthening exercise programs with/without other types of therapeutic exercises are generally effective for improving knee osteoarthritis management within a six-month period. Strengthening exercise programs demonstrated a significant improvement for pain relief (four Grade A, ten Grade B, two Grade C+), physical function (four Grade A, eight Grade B) and quality of life (three Grade B). Strengthening in combination with other types of exercises (coordination, balance, functional) showed a significant improvement in pain relief (three Grade A, 11 Grade B, eight Grade C+), physical function (two Grade A, four Grade B, three Grade C+) and quality of life (one Grade A, one Grade C+). There are a variety of choices for strengthening exercise programs with positive recommendations for healthcare professionals and knee osteoarthritis patients. There is a need to develop combined behavioral and muscle-strengthening strategies to improve long-term maintenance of regular strengthening exercise programs.

Stress Corrosion Cracking of Ferritic Materials for Fossil Power Generation Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pawel, Steven J; Siefert, John A.

2014-01-01

Creep strength enhanced ferritic (CSEF) steels Grades 23, 24, 91, and 92 have been widely implemented in the fossil fired industry for over two decades. The stress corrosion cracking (SCC) behavior of these materials with respect to mainstay Cr-Mo steels (such as Grades 11, 12 and 22) has not been properly assessed, particularly in consideration of recent reported issues of SCC in CSEF steels. This report details the results of Jones test exposures of a wide range of materials (Grades 11, 22, 23, 24, and 92), material conditions (as-received, improper heat treatments, normalized, weldments) and environments (salt fog; tube cleaningmore » environments including decreasing, scale removal, and passivation; and high temperature water) to compare the susceptibility to cracking of these steels. In the as-received (normalized and tempered) condition, none of these materials are susceptible to SCC in the environments examined. However, in the hardened condition, certain combinations of environment and alloy reveal substantial SCC susceptibility.« less

Dynamic fracture toughness of ASME SA508 Class 2a ASME SA533 grade A Class 2 base and heat affected zone material and applicable weld metals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Logsdon, W.A.; Begley, J.A.; Gottshall, C.L.

1978-03-01

The ASME Boiler and Pressure Vessel Code, Section III, Article G-2000, requires that dynamic fracture toughness data be developed for materials with specified minimum yield strengths greater than 50 ksi to provide verification and utilization of the ASME specified minimum reference toughness K/sub IR/ curve. In order to qualify ASME SA508 Class 2a and ASME SA533 Grade A Class 2 pressure vessel steels (minimum yield strengths equal 65 kip/in./sup 2/ and 70 kip/in./sup 2/, respectively) per this requirement, dynamic fracture toughness tests were performed on these materials. All dynamic fracture toughness values of SA508 Class 2a base and HAZ material,more » SA533 Grade A Class 2 base and HAZ material, and applicable weld metals exceeded the ASME specified minimum reference toughness K/sub IR/ curve.« less

Seismic performance of circular reinforced concrete bridge columns constructed with grade 80 reinforcement.

DOT National Transportation Integrated Search

2014-08-01

This project assessed the use of ASTM A706 Grade 80 reinforcing bars in reinforced concrete columns. : Grade 80 is not currently allowed in reinforced concrete columns due to lack of information on the : material characteristics and column performanc...

Strain-Tuning Atomic Substitution in Two-Dimensional Atomic Crystals.

PubMed

Li, Honglai; Liu, Hongjun; Zhou, Linwei; Wu, Xueping; Pan, Yuhao; Ji, Wei; Zheng, Biyuan; Zhang, Qinglin; Zhuang, Xiujuan; Zhu, Xiaoli; Wang, Xiao; Duan, Xiangfeng; Pan, Anlian

2018-05-22

Atomic substitution offers an important route to achieve compositionally engineered two-dimensional nanostructures and their heterostructures. Despite the recent research progress, the fundamental understanding of the reaction mechanism has still remained unclear. Here, we reveal the atomic substitution mechanism of two-dimensional atomic layered materials. We found that the atomic substitution process depends on the varying lattice constant (strain) in monolayer crystals, dominated by two strain-tuning (self-promoted and self-limited) mechanisms using density functional theory calculations. These mechanisms were experimentally confirmed by the controllable realization of a graded substitution ratio in the monolayers by controlling the substitution temperature and time and further theoretically verified by kinetic Monte Carlo simulations. The strain-tuning atomic substitution processes are of general importance to other two-dimensional layered materials, which offers an interesting route for tailoring electronic and optical properties of these materials.

Multi-material Additive Manufacturing of Metamaterials with Giant, Tailorable Negative Poisson's Ratios.

PubMed

Chen, Da; Zheng, Xiaoyu

2018-06-14

Nature has evolved with a recurring strategy to achieve unusual mechanical properties through coupling variable elastic moduli from a few GPa to below KPa within a single tissue. The ability to produce multi-material, three-dimensional (3D) micro-architectures with high fidelity incorporating dissimilar components has been a major challenge in man-made materials. Here we show multi-modulus metamaterials whose architectural element is comprised of encoded elasticity ranging from rigid to soft. We found that, in contrast to ordinary architected materials whose negative Poisson's ratio is dictated by their geometry, these type of metamaterials are capable of displaying Poisson's ratios from extreme negative to zero, independent of their 3D micro-architecture. The resulting low density metamaterials is capable of achieving functionally graded, distributed strain amplification capabilities within the metamaterial with uniform micro-architectures. Simultaneous tuning of Poisson's ratio and moduli within the 3D multi-materials could open up a broad array of material by design applications ranging from flexible armor, artificial muscles, to actuators and bio-mimetic materials.

Direct laser metal sintering as a new approach to fabrication of an isoelastic functionally graded material for manufacture of porous titanium dental implants.

PubMed

Traini, T; Mangano, C; Sammons, R L; Mangano, F; Macchi, A; Piattelli, A

2008-11-01

This work focuses on a titanium alloy implants incorporating a gradient of porosity, from the inner core to the outer surface, obtained by laser sintering of metal powder. Surface appearance, microstructure, composition, mechanical properties and fractography were evaluated. All the specimens were prepared by a selective laser sintering procedure using a Ti-6Al-4V alloy powder with a particle size of 1-10 microm. The morphological and chemical analyses were performed by SEM and energy dispersive X-ray spectroscopy. The flexure strength was determined by a three-point bend test using a universal testing machine. The surface roughness was investigated using a confocal scanning laser microscope. The surface roughness variation was statistically evaluated by use of a Chi square test. A p value of <0.05 was considered statistically significant. The original surface microstructure consisted of roughly spherical particles, diameter range 5-50 microm. After exposure to hydrofluoric acid some of these were removed and the microsphere diameter then ranged from 5.1 microm to 26.8 microm. Following an organic acid treatment, particles were replaced by grooves 14.6-152.5 microm in width and 21.4-102.4 microm depth. The metal core consisted of columnar beta grains with alpha and beta laths within the grains. The alloy was composed of 90.08% Ti, 5.67% Al and 4.25% V. The Young's modulus of the inner core material was 104+/-7.7 GPa; while that of the outer porous material was 77+/-3.5 GPa. The fracture face showed a dimpled appearance typical of ductile fracture. In conclusion, laser metal sintering proved to be an efficient means of construction of dental implants with a functionally graded material which is better adapted to the elastic properties of the bone. Such implants should minimize stress shielding effects and improve long-term performance.

Readability assessment of online urology patient education materials.

PubMed

Colaco, Marc; Svider, Peter F; Agarwal, Nitin; Eloy, Jean Anderson; Jackson, Imani M

2013-03-01

The National Institutes of Health, American Medical Association, and United States Department of Health and Human Services recommend that patient education materials be written at a fourth to sixth grade reading level to facilitate comprehension. We examined and compared the readability and difficulty of online patient education materials from the American Urological Association and academic urology departments in the Northeastern United States. We assessed the online patient education materials for difficulty level with 10 commonly used readability assessment tools, including the Flesch Reading Ease Score, Flesch-Kincaid Grade Level, Simple Measure of Gobbledygook, Gunning Frequency of Gobbledygook, New Dale-Chall Test, Coleman-Liau index, New Fog Count, Raygor Readability Estimate, FORCAST test and Fry score. Most patient education materials on the websites of these programs were written at or above the eleventh grade reading level. Urological online patient education materials are written above the recommended reading level. They may need to be simplified to facilitate better patient understanding of urological topics. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Domain General Mediators of the Relation between Kindergarten Number Sense and First-Grade Mathematics Achievement

PubMed Central

Hassinger-Das, Brenna; Jordan, Nancy C.; Glutting, Joseph; Irwin, Casey; Dyson, Nancy

2013-01-01

Domain general skills that mediate the relation between kindergarten number sense and first-grade mathematics skills were investigated. Participants were 107 children who displayed low number sense in the fall of kindergarten. Controlling for background variables, multiple regression analyses showed that attention problems and executive functioning both were unique predictors of mathematics outcomes. Attention problems were more important for predicting first-grade calculation performance while executive functioning was more important for predicting first-grade performance on applied problems. Moreover, both executive functioning and attention problems were unique partial mediators of the relationship between kindergarten and first-grade mathematics skills. The results provide empirical support for developing interventions that target executive functioning and attention problems in addition to instruction in number skills for kindergartners with initial low number sense. PMID:24237789

Domain-general mediators of the relation between kindergarten number sense and first-grade mathematics achievement.

PubMed

Hassinger-Das, Brenna; Jordan, Nancy C; Glutting, Joseph; Irwin, Casey; Dyson, Nancy

2014-02-01

Domain-general skills that mediate the relation between kindergarten number sense and first-grade mathematics skills were investigated. Participants were 107 children who displayed low number sense in the fall of kindergarten. Controlling for background variables, multiple regression analyses showed that both attention problems and executive functioning were unique predictors of mathematics outcomes. Attention problems were more important for predicting first-grade calculation performance, whereas executive functioning was more important for predicting first-grade performance on applied problems. Moreover, both executive functioning and attention problems were unique partial mediators of the relationship between kindergarten and first-grade mathematics skills. The results provide empirical support for developing interventions that target executive functioning and attention problems in addition to instruction in number skills for kindergartners with initial low number sense. Copyright © 2013 Elsevier Inc. All rights reserved.

Readability of Invasive Procedure Consent Forms

PubMed Central

Eltorai, Adam E. M.; Naqvi, Syed S.; Ghanian, Soha; Eberson, Craig P.; Weiss, Arnold‐Peter C.; Born, Christopher T.

2015-01-01

Abstract Background Informed consent is a pillar of ethical medicine which requires patients to fully comprehend relevant issues including the risks, benefits, and alternatives of an intervention. Given the average reading skill of US adults is at the 8th grade level, the American Medical Association (AMA) and the National Institutes of Health (NIH) recommend patient information materials should not exceed a 6th grade reading level. We hypothesized that text provided in invasive procedure consent forms would exceed recommended readability guidelines for medical information. Materials and methods To test this hypothesis, we gathered procedure consent forms from all surgical inpatient hospitals in the state of Rhode Island. For each consent form, readability analysis was measured with the following measures: Flesch Reading Ease Formula, Flesch–Kincaid Grade Level, Fog Scale, SMOG Index, Coleman–Liau Index, Automated Readability Index, and Linsear Write Formula. These readability scores were used to calculate a composite Text Readability Consensus Grade Level. Results Invasive procedure consent forms were found to be written at an average of 15th grade level (i.e., third year of college), which is significantly higher than the average US adult reading level of 8th grade (p < 0.0001) and the AMA/NIH recommended readability guidelines for patient materials of 6th grade (p < 0.0001). Conclusion Invasive procedure consent forms have readability levels which makes comprehension difficult or impossible for many patients. Efforts to improve the readability of procedural consent forms should improve patient understanding regarding their healthcare decisions. PMID:26678039

Fabrication and characterization of compositionally-graded shape memory alloy films

NASA Astrophysics Data System (ADS)

Cole, Daniel Paul

2009-12-01

The miniaturization of engineering devices has created interest in new actuation methods capable of high power and high frequency responses. Shape memory alloy (SMA) thin films have exhibited one of the highest power densities of any material used in these actuation schemes. However, they currently require complex thermomechanical training in order to be actuated, which becomes more difficult as devices approach the microscale. Previous studies have indicated that SMA films with compositional gradients have the added feature of an intrinsic two-way shape memory effect (SME). In this work, a new method for processing and characterizing compositionally-graded transformable thin films is presented. Graded NiTi SMA films were processed using magnetron sputtering. Single and multilayer graded films were deposited onto bulk NiTi substrates and single crystal silicon substrates, respectively. Annealing the films naturally produced a compositional gradient across the film-substrate or film-film interface through diffusion modification. The films were directly characterized using a combination of atomic force microscopy (AFM), x-ray diffraction and Auger electron spectroscopy. The compositional gradient was indirectly characterized by measuring the variation in mechanical properties as a function of depth using nanoindentation. The similarity of the indentation response on graded films of varying thickness was used to estimate the width of the graded interface. The nanoindentation response was predicted using an analysis that accounted for the transformation effects occurring under the tip during loading and the variation of elastic modulus resulting from the compositional gradient. The recovery mechanisms of the graded films are compared with homogeneous films using a new nanoscale technique. An AFM integrated with a heating and cooling stage was used to observe the recovery of inelastic deformation caused through nanoindentation. The graded films exhibited a two-way SME with a reduced hysteresis, while the homogeneous films exhibited the classical one-way SME. The fabrication and characterization techniques developed in this work have the potential to be applied to general graded and multi-layer film systems.

Optimization of BI test parameters to investigate mechanical properties of Grade 92 steel

NASA Astrophysics Data System (ADS)

Barbadikar, Dipika R.; Vincent, S.; Ballal, Atul R.; Peshwe, Dilip R.; Mathew, M. D.

2018-04-01

The ball indentation (BI) testing is used to evaluate the tensile properties of materials namely yield strength, strength coefficient, ultimate tensile strength, and strain hardening exponent. The properties evaluated depend on a number of BI test parameters. These parameters include the material constants like yield slope (YS), constraint factor (CF), yield offset parameter (YOP). Number of loading/unloading cycles, preload, indenter size and depth of penetration of indenter also affects the properties. In present investigation the effect of these parameters on the stress-strain curve of normalized and tempered Grade 92 steel is evaluated. Grade 92 is a candidate material for power plant application over austenitic stainless steel and derives its strength from M23C6, MX precipitates and high dislocation density. CF, YS and YOP changed the strength properties considerably. Indenter size effect resulted in higher strength for smaller indenter. It is suggested to use larger indenter diameter and higher number of loading cycles for GRADE 92 steel to get best results using BI technique.

Project ACE Activity Sets. Book II: Grades 6 and 7.

ERIC Educational Resources Information Center

Eden City Schools, NC.

The document contains eight activity sets suitable for grades 6 and 7. Topics focus on governmental, social, and educational systems in foreign countries. Each activity set contains background reading materials, resources, concepts, general objectives, and instructional objectives. Grade 6 sets are "Soviet Youth Organizations,""How…

Seventh Grade Interdisciplinary Packet (Science-Social Studies).

ERIC Educational Resources Information Center

Madison Public Schools, WI. Dept. of Curriculum Development.

GRADES OR AGES: Grade 7. SUBJECT MATTER: Science and Social Studies. ORGANIZATION AND PHYSICAL APPEARANCE: This guide presents a series of earth sciences units which would have interdisciplinary potential specifically in the area of social studies. Introductory material includes a rationale, evaluation procedures, 44 "key" environmental concepts,…

76 FR 5120 - Highway-Rail Grade Crossing; Safe Clearance

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-28

... driver from entering onto a highway-rail grade crossing unless there is sufficient space to drive... crossing unless there is sufficient space to drive completely through the grade crossing without stopping... as the ``clear storage distance.'' \\1\\ Chapter 8 guidance material also refers to ``storage space...

Mammography Patient Information at Hospital Websites: Most Neither Comprehensible Nor Guideline Supported.

PubMed

Sadigh, Gelareh; Singh, Kush; Gilbert, Kirven; Khan, Ramsha; Duszak, Abigail M; Duszak, Richard

2016-11-01

Ongoing controversy regarding screening mammography guidelines has created confusion for many patients. Given recommendations that patient educational material be prepared at or below the 7th grade reading level of average Americans, the purpose of this study was to assess the readability of online mammography information offered by hospitals nationwide. During 2015, online mammography patient educational materials were identified for all Medicare-recognized hospitals nationwide for which screening mammography metrics were publicly available. Patient educational materials were assessed using six validated readability score algorithms. All references to official screening guidelines were captured. Of 4105 hospitals nationwide, 3252 had websites and confirmable screening mammography services. Of those, 1753 (54%) offered mammography information material online. Only 919 (28%) referenced any professional society guidelines. After excluding information not formatted in HTML and shorter than 100 words (to improve algorithm reliability), 1524 hospital mammography webpages were assessed for grade level scores. Nationally, the mean of each readability score for all hospitals varied between the 10th and 14th grade levels, all higher than the recommended 7th grade level (p < 0.001). At the individual hospital level, only 14 hospitals (0.4%) had mean scores at or below the 7th grade level. Of U.S. hospitals that offer screening mammography and have websites, only 54% provide online mammography educational material. Of those, only 0.4% present information at a reading level comprehensible to average Americans, and only 28% offer specific information to help patients reconcile conflicting guidelines. Health systems offering mammography should strive to better meet women's health information and literacy needs.

AGC 2 Irradiated Material Properties Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rohrbaugh, David Thomas

2017-05-01

The Advanced Reactor Technologies Graphite Research and Development Program is conducting an extensive graphite irradiation experiment to provide data for licensing of a high temperature reactor (HTR) design. In past applications, graphite has been used effectively as a structural and moderator material in both research and commercial high temperature gas cooled reactor designs. , Nuclear graphite H 451, used previously in the United States for nuclear reactor graphite components, is no longer available. New nuclear graphite grades have been developed and are considered suitable candidates for new HTR reactor designs. To support the design and licensing of HTR core componentsmore » within a commercial reactor, a complete properties database must be developed for these current grades of graphite. Quantitative data on in service material performance are required for the physical, mechanical, and thermal properties of each graphite grade, with a specific emphasis on data accounting for the life limiting effects of irradiation creep on key physical properties of the HTR candidate graphite grades. Further details on the research and development activities and associated rationale required to qualify nuclear grade graphite for use within the HTR are documented in the graphite technology research and development plan.« less

How readable are Australian paediatric oral health education materials?

PubMed

Arora, Amit; Lam, Andy S F; Karami, Zahra; Do, Loc Giang; Harris, Mark Fort

2014-09-02

The objective of this study was to analyse the readability of paediatric oral health education leaflets available in Australia. Forty paediatric oral health education materials were analysed for general readability according to the following parameters: Thoroughness; Textual framework; Terminology; and Readability (Flesch-Kincaid grade level (FKGL), Gunning Fog index (Fog) and Simplified Measure of Gobbledygook (SMOG)). Leaflets produced by the industry were among the hardest to read with an average readability at the 8th grade (8.4 ± 0.1). The readability of leaflets produced by the commercial sector was at the 7th grade (7.1 ± 1.7) and the government at the 6th grade (6.3 ± 1.9). The FKGL consistently yielded readabilities 2 grades below the Fog and SMOG indexes. In the content analyses, 14 essential paediatric oral health topics were noted and Early Childhood Caries (ECC) was identified as the most commonly used jargon term. Paediatric oral health education materials are readily available, yet their quality and readability vary widely and may be difficult to read for disadvantaged populations in Australia. A redesign of these leaflets while taking literacy into consideration is suggested.

Ottawa Panel evidence-based clinical practice guidelines for therapeutic exercise in the management of hip osteoarthritis.

PubMed

Brosseau, Lucie; Wells, George A; Pugh, Arlanna G; Smith, Christine Am; Rahman, Prinon; Àlvarez Gallardo, Inmaculada C; Toupin-April, Karine; Loew, Laurianne; De Angelis, Gino; Cavallo, Sabrina; Taki, Jade; Marcotte, Rachel; Fransen, Marlene; Hernandez-Molina, Gabriela; Kenny, Glen P; Regnaux, Jean-Philippe; Lefevre-Colau, Marie-Martine; Brooks, Sydney; Laferriere, Lucie; McLean, Linda; Longchamp, Guy

2016-10-01

The primary objective is to identify effective land-based therapeutic exercise interventions and provide evidence-based recommendations for managing hip osteoarthritis. A secondary objective is to develop an Ottawa Panel evidence-based clinical practice guideline for hip osteoarthritis. The search strategy and modified selection criteria from a Cochrane review were used. Studies included hip osteoarthritis patients in comparative controlled trials with therapeutic exercise interventions. An Expert Panel arrived at a Delphi survey consensus to endorse the recommendations. The Ottawa Panel hierarchical alphabetical grading system (A, B, C+, C, D, D+, or D-) considered the study design (level I: randomized controlled trial and level II: controlled clinical trial), statistical significance (p < 0.5), and clinical importance (⩾15% improvement). Four high-quality studies were included, which demonstrated that variations of strength training, stretching, and flexibility exercises are generally effective for improving the management of hip osteoarthritis. Strength training exercises displayed the greatest improvements for pain (Grade A), disability (Grades A and C+), physical function (Grade A), stiffness (Grade A), and range of motion (Grade A) within a short time period (8-24 weeks). Stretching also greatly improved physical function (Grade A), and flexibility exercises improved pain (Grade A), range of motion (Grade A), physical function (Grade A), and stiffness (Grade C+). The Ottawa Panel recommends land-based therapeutic exercise, notably strength training, for management of hip osteoarthritis in reducing pain, stiffness and self-reported disability, and improving physical function and range of motion. © The Author(s) 2015.

Specific features of after-school program quality: associations with children's functioning in middle childhood.

PubMed

Pierce, Kim M; Bolt, Daniel M; Vandell, Deborah Lowe

2010-06-01

This longitudinal study examined associations between three after-school program quality features (positive staff-child relations, available activities, programming flexibility) and child developmental outcomes (reading and math grades, work habits, and social skills with peers) in Grade 2 and then Grade 3. Participants (n = 120 in Grade 2, n = 91 in Grade 3) attended after-school programs more than 4 days per week, on average. Controlling for child and family background factors and children's prior functioning on the developmental outcomes, positive staff-child relations in the programs were positively associated with children's reading grades in both Grades 2 and 3, and math grades in Grade 2. Positive staff-child relations also were positively associated with social skills in Grade 2, for boys only. The availability of a diverse array of age-appropriate activities at the programs was positively associated with children's math grades and classroom work habits in Grade 3. Programming flexibility (child choice of activities) was not associated with child outcomes.

An analytical method for free vibration analysis of functionally graded beams with edge cracks

NASA Astrophysics Data System (ADS)

Wei, Dong; Liu, Yinghua; Xiang, Zhihai

2012-03-01

In this paper, an analytical method is proposed for solving the free vibration of cracked functionally graded material (FGM) beams with axial loading, rotary inertia and shear deformation. The governing differential equations of motion for an FGM beam are established and the corresponding solutions are found first. The discontinuity of rotation caused by the cracks is simulated by means of the rotational spring model. Based on the transfer matrix method, then the recurrence formula is developed to get the eigenvalue equations of free vibration of FGM beams. The main advantage of the proposed method is that the eigenvalue equation for vibrating beams with an arbitrary number of cracks can be conveniently determined from a third-order determinant. Due to the decrease in the determinant order as compared with previous methods, the developed method is simpler and more convenient to analytically solve the free vibration problem of cracked FGM beams. Moreover, free vibration analyses of the Euler-Bernoulli and Timoshenko beams with any number of cracks can be conducted using the unified procedure based on the developed method. These advantages of the proposed procedure would be more remarkable as the increase of the number of cracks. A comprehensive analysis is conducted to investigate the influences of the location and total number of cracks, material properties, axial load, inertia and end supports on the natural frequencies and vibration mode shapes of FGM beams. The present work may be useful for the design and control of damaged structures.

Synthesis and microwave absorbing characteristics of functionally graded carbonyl iron/polyurethane composites

NASA Astrophysics Data System (ADS)

Yang, R. B.; Liang, W. F.; Wu, C. H.; Chen, C. C.

2016-05-01

Radar absorbing materials (RAMs) also known as microwave absorbers, which can absorb and dissipate incident electromagnetic wave, are widely used in the fields of radar-cross section reduction, electromagnetic interference (EMI) reduction and human health protection. In this study, the synthesis of functionally graded material (FGM) (CI/Polyurethane composites), which is fabricated with semi-sequentially varied composition along the thickness, is implemented with a genetic algorithm (GA) to optimize the microwave absorption efficiency and bandwidth of FGM. For impedance matching and broad-band design, the original 8-layered FGM was obtained by the GA method to calculate the thickness of each layer for a sequential stacking of FGM from 20, 30, 40, 50, 60, 65, 70 and 75 wt% of CI fillers. The reflection loss of the original 8-layered FGM below -10 dB can be obtained in the frequency range of 5.12˜18 GHz with a total thickness of 9.66 mm. Further optimization reduces the number of the layers and the stacking sequence of the optimized 4-layered FGM is 20, 30, 65, 75 wt% with thickness of 0.8, 1.6, 0.6 and 1.0 mm, respectively. The synthesis and measurement of the optimized 4-layered FGM with a thickness of 4 mm reveal a minimum reflection loss of -25.2 dB at 6.64 GHz and its bandwidth below - 10 dB is larger than 12.8 GHz.

Get on Board the Underground Railroad: A Sample Unit for Fifth-Grade History Students.

ERIC Educational Resources Information Center

Ferguson, Phyllis M.; Young, Terrell A.

1996-01-01

Reviews the materials and procedures used in a fifth-grade history unit on the Underground Railroad. The unit integrated a variety of teaching methods and materials making extensive use of historical literature, K-W-L (what we Know, what we Want to find out, what we Learned) charts, and activities aimed at different learning styles. (MJP)

Materiales en Marcha para el Esfuerzo Bilingue--Bicultural (Materials on the March for the Promotion of Bilingualism/Biculturalism), October 1972.

ERIC Educational Resources Information Center

San Diego City Schools, CA.

This newsletter seeks to promote the concept of bilingual-bicultural education. Among its articles are "Selection of Social Studies Resources,""Capturing a Child's Fancy: Read-Aloud Books," and "Ana's and Marta's Toast to Second-Grade Social Studies." Recommended reading materials in the fields of elementary Mexican history, second-grade social…

PROGRAM PLANNING FOR HOME ECONOMICS IN SECONDARY SCHOOLS IN MINNESOTA, GRADES 7-12, A RESOURCE UNIT IN FOODS AND NUTRITION. CURRICULUM BULLETIN NO. 12 A.

ERIC Educational Resources Information Center

Minnesota State Dept. of Education, St. Paul.

CURRICULUM MATERIALS TO HELP TEACHERS IN DEVELOPING SPECIFIC PLANS FOR TEACHING FOODS AND NUTRITION IN GRADES 7 THROUGH 12 ARE PRESENTED. CLASSROOM TEACHERS, SUPERVISORS, TEACHER EDUCATORS, AND CURRICULUM DEVELOPMENT STUDENTS CONTRIBUTED TO THE STATEWIDE CURRICULUM PROJECT WHICH DEVELOPED THE MATERIALS. MAJOR CONCEPTS INCORPORATED INTO THE UNITS…

Electrical Energy. 7th and 8th Grade Agriculture Science Curriculum. Teacher Materials.

ERIC Educational Resources Information Center

Southern Illinois Univ., Carbondale. Dept. of Agricultural Education and Mechanization.

This curriculum guide, the fifth in a set of six, contains teacher and student materials for a unit on electrical energy prepared as part of a seventh- and eighth-grade agricultural science curriculum that is integrated with science instruction. The guide contains the state goals and sample learning objectives for each goal for students in grades…

Small Schools Mathematics Curriculum, Grades 7-8: Reading, Language Arts, Mathematics, Science, Social Studies. Scope, Objectives, Activities, Resources, Monitoring Procedures.

ERIC Educational Resources Information Center

Hartl, David, Ed.; And Others

Developed during the 1976-77 school year to assist Washington grade 7-8 teachers in small school districts with the improvement of curriculum and instruction, this learning-objective-based curriculum suggests activities, monitoring procedures and resources for mathematics. Introductory materials describe the organization of Small School materials,…

Indians of Northwest California: History/Social Science and Literature Based Curriculum Units.

ERIC Educational Resources Information Center

Supahan, Sarah, Ed.

This curriculum guide was developed to provide material about the Indian culture of Northwest California for students in grades K-6. Many of the units were developed for a specific grade, but can be adapted for older or younger children. The material can be integrated with such curricular areas as language, literature, social studies, science, and…

The feasibility of ranking material fracture toughness by ultrasonic attenuation measurements

NASA Technical Reports Server (NTRS)

Vary, A.

1975-01-01

A preliminary study was conducted to assess the feasibility of ultrasonically ranking material fracture toughness. Specimens of two grades of maraging steel for which fracture toughness values were measured were subjected to ultrasonic probing. The slope of the attenuation coefficient vs frequency curve was empirically correlated with the plane strain fracture toughness value for each grade of steel.

The feasibility of ranking material fracture toughness by ultrasonic attenuation measurements

NASA Technical Reports Server (NTRS)

Vary, A.

1975-01-01

A preliminary study was conducted to assess the feasibility of ultrasonically ranking material fracture toughness. Specimens of two grades of maraging steel for which fracture toughness values were measured were subjected to ultrasonic probing. The slope of the attenuation coefficient versus frequency curve was empirically correlated with the plane strain fracture toughness value for each grade of steel.

Computer Assisted Educational Material Preparation for Fourth Grade Primary School Students' English Language Class in Teaching Numbers

ERIC Educational Resources Information Center

Yüzen, Abdulkadir; Karamete, Aysen

2016-01-01

In this study, using ADDIE instructional design model, it is aimed to prepare English language educational material for 4th grade primary students to teach them numbers. At the same time, ARCS model of motivation's attention, relevance and satisfaction phases are also taken into consideration. This study also comprises of Design Based Research…

An Investigation of the Effects of Imagination Enhancement Materials on the Creative Abilities of Fifth Grade Students.

ERIC Educational Resources Information Center

Radis, Michael William

The purpose of this study was to determine if the use of classroom activities to enhance children's imaginations could improve their creative abilities. Subjects included 25 fifth-grade students in the Grand Forks, North Dakota, school district. Students were given the Torrance Tests of Creative Thinking and were provided with materials designed…

Tensiometer and method of determining soil moisture potential in below-grade earthen soil

DOEpatents

Hubbell, Joel M.; Sisson, James B.

1997-01-01

A portable tensiometer to in situ determine below-grade soil moisture potential of earthen soil includes, a) a body having opposing first and second ends and being adapted for complete insertion into earthen soil below grade; b) a porous material provided at the first body end, the porous material at least in part defining a fluid chamber within the body at the first body end, the fluid chamber being fluidically sealed within the body but for the porous material; c) a degassed liquid received within the fluid chamber; d) a pressure transducer mounted in fluid communication with the fluid chamber; e) the body, pressure transducer and degassed liquid having a combined mass; f) a flexible suspension line connected to the body adjacent the second body end, the flexible line being of sufficient strength to gravitationally freely self suspend the combined mass; and c) the combined mass being sufficient to effectively impart hydraulic communication between below-grade earthen soil contacted by the porous material under the weight of the combined mass. Tensiometers configured to engage the sidewalls of an earthen opening are also disclosed. Methods of taking tensiometric measurements are also disclosed.

Tensiometer and method of determining soil moisture potential in below-grade earthen soil

DOEpatents

Hubbell, J.M.; Sisson, J.B.

1997-07-08

A portable tensiometer to in-situ determine below-grade soil moisture potential of earthen soil includes, (a) a body having opposing first and second ends and being adapted for complete insertion into earthen soil below grade; (b) a porous material provided at the first body end, the porous material at least in part defining a fluid chamber within the body at the first body end, the fluid chamber being fluidically sealed within the body but for the porous material; (c) a degassed liquid received within the fluid chamber; (d) a pressure transducer mounted in fluid communication with the fluid chamber; (e) the body, pressure transducer and degassed liquid having a combined mass; (f) a flexible suspension line connected to the body adjacent the second body end, the flexible line being of sufficient strength to gravitationally freely self suspend the combined mass; and (g) the combined mass being sufficient to effectively impart hydraulic communication between below-grade earthen soil contacted by the porous material under the weight of the combined mass. Tensiometers configured to engage the sidewalls of an earthen opening are also disclosed. Methods of taking tensiometric measurements are also disclosed. 12 figs.

Solar Tests of Aperture Plate Materials for Solar Thermal Dish Collectors

NASA Technical Reports Server (NTRS)

Jaffe, L. D.

1984-01-01

If a malfunction occurs in a solar thermal point-focus distributed receiver power plant while a concentrator is pointed at the Sun, motion of the concentrator may stop. As the Sun moves relative to the Earth, the spot of concentrated sunlight then slowly walks off the receiver aperture, across the receiver face plate, and perhaps across adjacent portions of the concentrator. Intense local heating by the concentrated sunlight may damage or destroy these parts. The behavior of various materials under conditions simulating walk-off of a parabolic dish solar collector were evaluated. Each test consisted of exposure to concentrated sunlight at a peak flux density of about 7000 kW/square meter for 15 minutes. Types of materials tested included graphite, silicon carbide, silica, various silicates, alumina, zirconia, aluminum, copper, steel, and polytetrafluoroethylene. The only material that neither cracked nor melted was grade G-90 graphite. Grade CS graphite, a lower cost commercial grade, cracked half-way across, but did not fall apart. Both of these grades are medium-grain extruded graphites. A graphite cloth (graphitized polyacrylonitrile) showed fair performance when tested as a single thin ply; it might be useful as a multi-ply assembly. High purity slipcast silica showed some promise also.

Solar tests of aperture plate materials for solar thermal dish collectors

NASA Technical Reports Server (NTRS)

Jaffe, L. D.

1984-01-01

If a malfunction occurs in a solar thermal point-focus distributed receiver power plant while a concentrator is pointed at the sun, motion of the concentrator may stop. As the sun moves relative to the earth, the spot of concentrated sunlight then slowly walks off the receiver aperture, across the receiver face plate, and perhaps across adjacent portions of the concentrator. Intense local heating by the concentrated sunlight may damage or destroy these parts. The behavior of various materials under conditions simulating walk-off of a parabolic dish solar collector were evaluated. Each test consisted of exposure to concentrated sunlight at a peak flux density of about 7000 kW/square meter for 15 minutes. Types of materials tested included graphite, silicon carbide, silica, various silicates, alumina, zirconia, aluminum, copper, steel, and polytetrafluroethylene. The only material that neither cracked nor melted was grade G-90 graphite. Grade CS graphite, a lower cost commercial grade, cracked half-way across, but did not fail apart. Both of these grades are medium-grain extruded graphites. A graphite cloth (graphitized polyacrylonitrile) showed fair performance when tested as a single thin ply; it might be useful as a multi-ply assembly. High purity slipcast silica showed some promise also.

Solar tests of aperture plate materials for solar thermal dish collectors

NASA Technical Reports Server (NTRS)

Jaffe, L. D.

1984-01-01

If a malfunction occurs in a solar thermal point-focus distributed receiver power plant while a concentrator is pointed at the sun, motion of the concentrator may stop. As the sun moves relative to the earth, the spot of concentrated sunlight then slowly walks off the receiver aperture, across the receiver face plate, and perhaps across adjacent portions of the concentrator. Intense local heating by the concentrated sunlight may damage or destroy these parts. The behavior of various materials under conditions simulating walk-off of a parabolic dish solar collector were evaluated. Each test consisted of exposure to concentrated sunlight at a peak flux density of about 7000 kW/square meter for 15 minutes. Types of materials tested included graphite, silicon carbide, silica, various silicates, alumina, zirconia, aluminum, copper, steel, and polytetrafluoroethylene. The only material that neither cracked nor melted was grade G-90 graphite. Grade CS graphite, a lower cost commercial grade, cracked half-way across, but did not fall apart. Both of these grades are medium-grain extruded graphites. A graphite cloth (graphitized polyacrylonitrile) showed fair performance when tested as a single thin ply; it might be useful as a multi-ply assembly. High purity slipcast silica showed some promise also.

Refractive Error and Visual Functions in Children with Special Needs Compared with the First Grade School Students in Oman

PubMed Central

Vora, Urmi; Khandekar, Rajiv; Natrajan, Sarvanan; Al-Hadrami, Khalfan

2010-01-01

Background: We evaluated the refractive status and visual function of children with special needs (other handicap) in 2010 and compared them with healthy 1st grade school students in Oman. Materials and Methods: This was a cohort study. Optometrists recorded vision using a logarithm of minimum angle of resolution (LogMAR) chart. Preferential looking method was used for testing 31 children. Cycloplegic refraction was performed on all children. Contrast sensitivity was tested using 2.5%, 10%, and 100% contrast charts. Ocular movement, alignment, and anterior segment were also assessed. A pediatrician reviewed the health records of all the children at the time of their enrollment in this study to determine if the child had been diagnosed with a systemic condition or syndromes. The visual functions were assessed by study investigators. We estimated the rates and the risk of different visual function defects in children with special needs. Result: The prevalence of refractive error in 70 children (4.7 ± 0.8 years) with special needs (group 1) and 175 normal healthy first grade students (group 2) were 58.5% and 2.9%, respectively. The risk of refractive error was significantly higher in children with special needs [relative risk, 48.1 (95% confidence interval, 17.54–131.8)]. Hyperopia (>1.00 D), myopia (≥ 1.00D) and astigmatism (≥ ±1.00 D) were found in 18.6%, 24.3%, and 27.1%, respectively, in group 1. Six children in this group had defective near vision. Sixteen (80%) children with Down syndrome had refractive error. Seven (50%) children with developmental disorder showed decreased contrast sensitivity. Conclusion: Prevalence of uncorrected refractive error was much higher in children with special needs. Prevalence of strabismus, nystagmus, and reduced contrast sensitivity was also higher in children with special needs. Early vision screening, visual function assessment, correction of refractive error, and frequent follow-up are recommended. PMID:21180428

Hot-melt extruded filaments based on pharmaceutical grade polymers for 3D printing by fused deposition modeling.

PubMed

Melocchi, Alice; Parietti, Federico; Maroni, Alessandra; Foppoli, Anastasia; Gazzaniga, Andrea; Zema, Lucia

2016-07-25

Fused deposition modeling (FDM) is a 3D printing technique based on the deposition of successive layers of thermoplastic materials following their softening/melting. Such a technique holds huge potential for the manufacturing of pharmaceutical products and is currently under extensive investigation. Challenges in this field are mainly related to the paucity of adequate filaments composed of pharmaceutical grade materials, which are needed for feeding the FDM equipment. Accordingly, a number of polymers of common use in pharmaceutical formulation were evaluated as starting materials for fabrication via hot melt extrusion of filaments suitable for FDM processes. By using a twin-screw extruder, filaments based on insoluble (ethylcellulose, Eudragit(®) RL), promptly soluble (polyethylene oxide, Kollicoat(®) IR), enteric soluble (Eudragit(®) L, hydroxypropyl methylcellulose acetate succinate) and swellable/erodible (hydrophilic cellulose derivatives, polyvinyl alcohol, Soluplus(®)) polymers were successfully produced, and the possibility of employing them for printing 600μm thick disks was demonstrated. The behavior of disks as barriers when in contact with aqueous fluids was shown consistent with the functional application of the relevant polymeric components. The produced filaments were thus considered potentially suitable for printing capsules and coating layers for immediate or modified release, and, when loaded with active ingredients, any type of dosage forms. Copyright © 2016 Elsevier B.V. All rights reserved.

[East Syracuse-Minoa Schools Environmental Education Materials, Elementary Package, Grade 1-Grade 5.

ERIC Educational Resources Information Center

East Syracuse - Minoa Central Schools, East Syracuse, NY.

This series of five environmental education units is designed for use in grades 1-5. The units are designed around the concepts of survival, interdependence, scarcity, recyclement, rights vs. responsibility, planning, valuing, social forces, and optimism. Each unit is further developed around environmental generalizations (subconcepts),…

7 CFR 868.313 - Grades and grade requirements for the class Brewers Milled Rice. (See also § 868.315.)

Code of Federal Regulations, 2013 CFR

2013-01-01

...) contains more than 15.0 percent of broken kernels that will pass through a 21/2 sieve; (h) contains two or....0 percent of material passing through a 30 sieve. This limit does not apply to the special grade...

7 CFR 868.313 - Grades and grade requirements for the class Brewers Milled Rice. (See also § 868.315.)

Code of Federal Regulations, 2014 CFR

2014-01-01

...) contains more than 15.0 percent of broken kernels that will pass through a 21/2 sieve; (h) contains two or....0 percent of material passing through a 30 sieve. This limit does not apply to the special grade...

7 CFR 868.313 - Grades and grade requirements for the class Brewers Milled Rice. (See also § 868.315.)

Code of Federal Regulations, 2012 CFR

2012-01-01

...) contains more than 15.0 percent of broken kernels that will pass through a 21/2 sieve; (h) contains two or....0 percent of material passing through a 30 sieve. This limit does not apply to the special grade...

Grade Expectations: Redux

ERIC Educational Resources Information Center

Miley, William M.; Gonsalves, Sonia

2004-01-01

We surveyed undergraduate students taking upper level psychology courses about their course and grade expectations as an extension of the work of Gaultney and Cann (2001) with introductory psychology students. More students believed success in a course was measured by good grades rather than by mastery of new material. They wanted effort to play a…

7 CFR 51.1404 - Tolerances.

Code of Federal Regulations, 2012 CFR

2012-01-01

... the grade other than for skin color. (3) For loose extraneous or foreign material, by weight. (i) 0.5... requirements for the grade or any specified color classification, including therein not more than 7 percent for... meet the color requirements for the grade or for any specified color classification, but which are not...

Eighth Grade Social Studies. An Experimental Program in Geography and Anthropology.

ERIC Educational Resources Information Center

Hanson, James; And Others

GRADES OR AGES: Grade 8. SUBJECT MATTER: Geography and Anthropology. ORGANIZATION AND PHYSICAL APPEARANCE: The introductory material includes descriptions of geography and anthropology as disciplines, the basic course objectives, techniques for evaluating objectives and a student self-evaluation form. The guide covers six units: 1) "What Kind of…

Modeling micromechanical measurements of depth-varying properties with scanning acoustic microscopy

NASA Astrophysics Data System (ADS)

Marangos, Orestes; Misra, Anil

2018-02-01

Scanning acoustic microscopy (SAM) has been applied to measure the near-surface elastic properties of materials. For many substrates, the near-surface property is not constant but varies with depth. In this paper, we aim to interpret the SAM data from such substrates by modeling the interaction of the focused ultrasonic field with a substrate having a near-surface graded layer. The focused ultrasonic field solutions were represented as spherical harmonic expansions while the substrate solutions were represented as plane wave expansions. The bridging of the two solutions was achieved through the decomposition of the ultrasonic pressure fields in their angular spectra. Parametric studies were performed, which showed that near-surface graded layers exhibit distinctive frequency dependence of their reflectance functions. This behavior is characteristic to the material property gradation profile as well as the extent of the property gradation. The developed model was used to explain the frequency-dependent reflection coefficients measured from an acid-etched dentin substrate. Based on the model calculations, the elastic property variations of the acid-etched dentin near-surface indicate that the topmost part of the etched layer is very soft (3-6 GPa) and transitions to the native dentin through a depth of 27 and 36 microns.

Socioeconomic inequalities in physical and mental functioning of British, Finnish, and Japanese civil servants: role of job demand, control, and work hours.

PubMed

Sekine, Michikazu; Chandola, Tarani; Martikainen, Pekka; Marmot, Michael; Kagamimori, Sadanobu

2009-11-01

This study aims to evaluate whether the pattern of socioeconomic inequalities in physical and mental functioning as measured by the Short Form 36 (SF-36) differs among employees in Britain, Finland, and Japan and whether work characteristics contribute to some of the health inequalities. The participants were 7340 (5122 men and 2218 women) British employees, 2297 (1638 men and 659 women) Japanese employees, and 8164 (1649 men and 6515 women) Finnish employees. All the participants were civil servants aged 40-60 years. Both male and female low grade employees had poor physical functioning in all cohorts. British and Japanese male low grade employees tended to have poor mental functioning but the associations were significant only for Japanese men. No consistent employment-grade differences in mental functioning were observed among British and Japanese women. Among Finnish men and women, high grade employees had poor mental functioning. In all cohorts, high grade employees had high control, high demands and long work hours. The grade differences in poor physical functioning and disadvantaged work characteristics among non-manual workers were somewhat smaller in the Finnish cohort than in the British and Japanese cohorts. Low control, high demands, and both short and long work hours were associated with poor functioning. When work characteristics were adjusted for, the socioeconomic differences in poor functioning were mildly attenuated in men, but the differences increased slightly in women. This study reconfirms the generally observed pattern of socioeconomic inequalities in health for physical functioning but not for mental functioning. The role of work characteristics in the relationship between socioeconomic status and health differed between men and women but was modest overall. We suggest that these differences in the pattern and magnitude of grade differences in work characteristics and health among the 3 cohorts may be attributable to the different welfare regimes among the 3 countries.

Socioeconomic Inequalities in Physical and Mental Functioning of British, Finnish, and Japanese Civil Servants: Role of Job Demand, Control, and Work Hours

PubMed Central

Chandola, Tarani; Martikainen, Pekka; Marmot, Michael; Kagamimori, Sadanobu

2009-01-01

This study aims to evaluate whether the pattern of socioeconomic inequalities in physical and mental functioning as measured by the Short Form 36 (SF-36) differs among employees in Britain, Finland, and Japan and whether work characteristics contribute to some of the health inequalities. The participants were 7340 (5122 men and 2218 women) British employees, 2297 (1638 men and 659 women) Japanese employees, and 8164 (1649 men and 6515 women) Finnish employees. All the participants were civil servants aged 40–60 years. Both male and female low grade employees had poor physical functioning in all cohorts. British and Japanese male low grade employees tended to have poor mental functioning but the associations were significant only for Japanese men. No consistent employment-grade differences in mental functioning were observed among British and Japanese women. Among Finnish men and women, high grade employees had poor mental functioning. In all cohorts, high grade employees had high control, high demands and long work hours. The grade differences in poor physical functioning and disadvantaged work characteristics among non-manual workers were somewhat smaller in the Finnish cohort than in the British and Japanese cohorts. Low control, high demands, and both short and long work hours were associated with poor functioning. When work characteristics were adjusted for, the socioeconomic differences in poor functioning were mildly attenuated in men, but the differences increased slightly in women. This study reconfirms the generally observed pattern of socioeconomic inequalities in health for physical functioning but not for mental functioning. The role of work characteristics in the relationship between socioeconomic status and health differed between men and women but was modest overall. We suggest that these differences in the pattern and magnitude of grade differences in work characteristics and health among the 3 cohorts may be attributable to the different welfare regimes among the 3 countries. PMID:19767137

Readability of online patient education materials on adult reconstruction Web sites.

PubMed

Polishchuk, Daniil L; Hashem, Jenifer; Sabharwal, Sanjeev

2012-05-01

Recommended readability of patient education materials is sixth-grade level or lower. Readability of 212 patient education materials pertaining to adult reconstruction topics available from the American Academy of Orthopaedic Surgeons, American Association of Hip and Knee Surgeons, and 3 other specialty and private practitioner Web sites was assessed using the Flesch-Kincaid grade formula. The mean Flesch-Kincaid score was 11.1 (range, 3-26.5). Only 5 (2%) articles had a readability level of sixth grade or lower. Readability of most of the articles for patient education on adult reconstruction Web sites evaluated may be too advanced for a substantial portion of patients. Further studies are needed to assess the optimal readability level of health information on the Internet. Copyright © 2012 Elsevier Inc. All rights reserved.

Computational Study of a Functionally Graded Ceramic-Metallic Armor

DTIC Science & Technology

2006-12-15

UNCLAS –Dist. A - Approved for public release Computational Study of a Functionally Graded Ceramic-Metallic Armor Douglas W. Templeton1, Tara J...efficiency of a postulated FGM ceramic-metallic armor system composed of aluminum nitride (AlN) and aluminum. The study had two primary...2006 2. REPORT TYPE N/ A 3. DATES COVERED - 4. TITLE AND SUBTITLE Computational Study of a Functionally Graded Ceramic-Metallic Armor 5a

Psychological Symptoms Linking Exposure to Community Violence and Academic Functioning in African American Adolescents

PubMed Central

Busby, Danielle R.; Lambert, Sharon F.; Ialongo, Nicholas S.

2013-01-01

African American adolescents are exposed disproportionately to community violence, increasing their risk for emotional and behavioral symptoms that can detract from learning and undermine academic outcomes. The present study examined whether aggressive behavior and depressive and anxious symptoms mediated the association between exposure to community violence and academic functioning, and if the indirect effects of community violence on academic functioning differed for boys and girls, in a community sample of urban African American adolescents (N = 491; 46.6% female). Structural equation modeling was used to examine the indirect effect of exposure to community violence in grade 6 on grade 8 academic functioning. Results revealed that aggression in grade 7 mediated the association between grade 6 exposure to community violence and grade 8 academic functioning. There were no indirect effects through depressive and anxious symptoms, and gender did not moderate the indirect effect. Findings highlight the importance of targeting aggressive behavior for youth exposed to community violence to not only improve their behavioral adjustment but also their academic functioning. Implications for future research are discussed. PMID:23277294

Social Competence and Social Support as Mediators between Comorbid Depressive and Conduct Problems and Functional Outcomes in Middle School Students

PubMed Central

Rockhill, Carol M.; Stoep, Ann Vander; McCauley, Elizabeth; Katon, Wayne J.

2009-01-01

This study examined the roles of social competence and social support as potential mediators of the association between psychopathology and functional outcomes in a middle school sample (n=521). Participants were stratified into four psychopathology risk groups (depression only, conduct problems only, comorbid depression and conduct problems, low symptoms) based on screening during early 6th grade. Functional outcomes were 6th grade point average (GPA) and parent rating of global adaptive functioning in their 7th grade student. Low levels of social competence were found to mediate the association between psychiatric symptoms and both lower grades and global functioning, for adolescents with depressive symptoms alone and with comorbid symptoms, but not for those with conduct problems alone. Lack of social support mediated the association between symptoms and lower grades for adolescents with depression alone and comorbid symptoms, but not those with conduct problems alone. These findings suggest that intervention to improve social competence and social support may enhance functional outcomes, especially for youth with depressive symptoms or comorbid depressive and conduct symptoms. PMID:18694594

Life cycle inventory for palm based plywood: A gate-to-gate case study

NASA Astrophysics Data System (ADS)

Ahmad, Shamim; Sahid, Ismail; Subramaniam, Vijaya; Muhamad, Halimah; Mokhtar, Anis

2013-11-01

The oil palm industry heavily relies on the world market. It is essential to ensure that the oil palm industry is ready to meet the demands and expectation of these overseas customers on the environmental performance of the oil palm industry. Malaysia produces 13.9 million tons of oil palm biomass including oil palm trunk (OPT), frond and empty fruits bunches (EFB) annually. OPT felled in some oil palm plantations during replanting is transported to various industries and one such industry is the plywood factories. In order to gauge the environmental performance of the use of OPT as plywood a Life Cycle Assessment (LCA) study was conducted for palm based plywood. LCA is an important tool to assess the environmental performance of a product or process. Life cycle inventory (LCI) is the heart of a LCA study. This LCI study has a gate-to-gate system boundary and the functional unit is 1 m3 palm plywood produced and covers three types of plywood; Moisture Resistance Plywood (MR), Weather Boiling Proof Plywood Grade 1 (WBP Grade 1) at Factory D and Weather Boiling Proof Plywood Grade 2 (WBP Grade 2) at Factory E. Both factories use two different types of drying processes; conventional drying at Factory D and kiln drying at Factory E. This inventory data was collected from two factories (D and E) representing 40% of Malaysia palm plywood industry. The inputs are mainly the raw materials which are the oil palm trunks and tropical wood veneers and the energy from diesel and electricity from grid which is mainly used for the drying process. The other inputs include water, urea formaldehyde, phenol formaldehyde, flour and melamine powder. The outputs are the biomass waste which consists of oil palm trunk off-cut and emission from boiler. Generally, all types of plywood production use almost same materials and processing methods in different quantities. Due to the different process efficiency, Factory D uses less input of raw materials and energy compared to Factory E.

Performance of a Medipix3RX spectroscopic pixel detector with a high resistivity gallium arsenide sensor.

PubMed

Hamann, Elias; Koenig, Thomas; Zuber, Marcus; Cecilia, Angelica; Tyazhev, Anton; Tolbanov, Oleg; Procz, Simon; Fauler, Alex; Baumbach, Tilo; Fiederle, Michael

2015-03-01

High resistivity gallium arsenide is considered a suitable sensor material for spectroscopic X-ray imaging detectors. These sensors typically have thicknesses between a few hundred μm and 1 mm to ensure a high photon detection efficiency. However, for small pixel sizes down to several tens of μm, an effect called charge sharing reduces a detector's spectroscopic performance. The recently developed Medipix3RX readout chip overcomes this limitation by implementing a charge summing circuit, which allows the reconstruction of the full energy information of a photon interaction in a single pixel. In this work, we present the characterization of the first Medipix3RX detector assembly with a 500 μm thick high resistivity, chromium compensated gallium arsenide sensor. We analyze its properties and demonstrate the functionality of the charge summing mode by means of energy response functions recorded at a synchrotron. Furthermore, the imaging properties of the detector, in terms of its modulation transfer functions and signal-to-noise ratios, are investigated. After more than one decade of attempts to establish gallium arsenide as a sensor material for photon counting detectors, our results represent a breakthrough in obtaining detector-grade material. The sensor we introduce is therefore suitable for high resolution X-ray imaging applications.

Thalamic diffusion differences related to cognitive function in white matter lesions.

PubMed

Fernández-Andújar, Marina; Soriano-Raya, Juan José; Miralbell, Júlia; López-Cancio, Elena; Cáceres, Cynthia; Bargalló, Núria; Barrios, Maite; Arenillas, Juan Francisco; Toran, Pere; Alzamora, Maite; Clemente, Imma; Dávalos, Antoni; Mataró, Maria

2014-05-01

Cerebral white matter lesions (WMLs) are related to cognitive deficits, probably due to a disruption of frontal-subcortical circuits. We explored thalamic diffusion differences related to white matter lesions (WMLs) and their association with cognitive function in middle-aged individuals. Ninety-six participants from the Barcelona-AsIA Neuropsychology Study were included. Participants were classified into groups based on low grade and high grade of periventricular hyperintensities (PVHs) and deep white matter hyperintensities (DWMHs). Tract-Based Spatial Statistics was used to study thalamic diffusion differences between groups. Mean fractional anisotropy (FA) values in significant areas were calculated for each subject and correlated with cognitive performance. Participants with high-grade PVHs and DWMHs showed lower FA thalamic values compared to those with low-grade PVHs and DWMHs, respectively. Decreased FA thalamic values in high-grade DWMHs, but not high-grade PVH, were related to lower levels of performance in psychomotor speed, verbal fluency, and visuospatial skills. Thalamic diffusion differences are related to lower cognitive function only in participants with high-grade DWMHs. These results support the hypothesis that fronto-subcortical disruption is associated with cognitive function only in DWMHs. Copyright © 2014 Elsevier Inc. All rights reserved.

High-grade ovarian cancer secreting effective exosomes in tumor angiogenesis.

PubMed

Yi, Huan; Ye, Jun; Yang, Xiao-Mei; Zhang, Li-Wen; Zhang, Zhi-Gang; Chen, Ya-Ping

2015-01-01

Ovarian cancer, the most lethal gynecological cancer, related closely to tumor stage. High-grade ovarian cancer always results in a late diagnose and high recurrence, which reduce survival within five years. Until recently, curable therapy is still under research and anti-angiogenesis proves a promising way. Tumor-derived exosomes are essential in tumor migration and metastases such as angiogenesis is enhanced by exosomes. In our study, we have made comparison between high-grade and unlikely high-grade serous ovarian cancer cells on exosomal function of endothelial cells proliferation, migration and tube formation. Exosomes derived from high-grade ovarian cancer have a profound impact on angiogenesis with comparison to unlikely high-grade ovarian cancer. Proteomic profiles revealed some potential proteins involved in exosomal function of angiogenesis such as ATF2, MTA1, ROCK1/2 and so on. Therefore, exosomes plays an influential role in angiogenesis in ovarian serous cancer and also function more effectively in high-grade ovarian cancer cells.

Analysis of thermoelastic characteristics in a thick walled FGM cylinder

NASA Astrophysics Data System (ADS)

Tanvir, A. N. M.; Islam, Md. Didarul; Ahmed, Faisal

2017-12-01

This study is concerned with the behavior of stress and strain in a thick walled functionally graded material (FGM) cylinder under internal pressure. The incompatible eigenstrain and equivalent eigenstrain developed in the cylinder, are taken into account. As a demonstration, a TiC/Al2O3 FGM cylinder is considered and different components of stress and strain are presented in order to study the effects of internal pressure, temperature difference (between room and sintering temperature), cylinder wall thickness and material distribution. The numerical result presented here shows that the thermoelastic characteristic like stress and strain of an FGM cylinder is significantly influenced by some of the above-mentioned parameters and can be controlled by properly controlling these parameters.

Comparison of the Diagnostic Accuracy of DSC- and Dynamic Contrast-Enhanced MRI in the Preoperative Grading of Astrocytomas.

PubMed

Nguyen, T B; Cron, G O; Perdrizet, K; Bezzina, K; Torres, C H; Chakraborty, S; Woulfe, J; Jansen, G H; Sinclair, J; Thornhill, R E; Foottit, C; Zanette, B; Cameron, I G

2015-11-01

Dynamic contrast-enhanced MR imaging parameters can be biased by poor measurement of the vascular input function. We have compared the diagnostic accuracy of dynamic contrast-enhanced MR imaging by using a phase-derived vascular input function and "bookend" T1 measurements with DSC MR imaging for preoperative grading of astrocytomas. This prospective study included 48 patients with a new pathologic diagnosis of an astrocytoma. Preoperative MR imaging was performed at 3T, which included 2 injections of 5-mL gadobutrol for dynamic contrast-enhanced and DSC MR imaging. During dynamic contrast-enhanced MR imaging, both magnitude and phase images were acquired to estimate plasma volume obtained from phase-derived vascular input function (Vp_Φ) and volume transfer constant obtained from phase-derived vascular input function (K(trans)_Φ) as well as plasma volume obtained from magnitude-derived vascular input function (Vp_SI) and volume transfer constant obtained from magnitude-derived vascular input function (K(trans)_SI). From DSC MR imaging, corrected relative CBV was computed. Four ROIs were placed over the solid part of the tumor, and the highest value among the ROIs was recorded. A Mann-Whitney U test was used to test for difference between grades. Diagnostic accuracy was assessed by using receiver operating characteristic analysis. Vp_ Φ and K(trans)_Φ values were lower for grade II compared with grade III astrocytomas (P < .05). Vp_SI and K(trans)_SI were not significantly different between grade II and grade III astrocytomas (P = .08-0.15). Relative CBV and dynamic contrast-enhanced MR imaging parameters except for K(trans)_SI were lower for grade III compared with grade IV (P ≤ .05). In differentiating low- and high-grade astrocytomas, we found no statistically significant difference in diagnostic accuracy between relative CBV and dynamic contrast-enhanced MR imaging parameters. In the preoperative grading of astrocytomas, the diagnostic accuracy of dynamic contrast-enhanced MR imaging parameters is similar to that of relative CBV. © 2015 by American Journal of Neuroradiology.

Comparative Readability of Shoulder and Elbow Patient Education Materials within Orthopaedic Websites.

PubMed

Beutel, Bryan G; Danna, Natalie R; Melamed, Eitan; Capo, John T

2015-12-01

There is growing concern that the readability of online orthopaedic patient education materials are too difficult for the general public to fully understand. It is recommended that this information be at the sixth grade reading level or lower. This study compared the readability of shoulder and elbow education articles from the American Academy of Orthopaedic Surgeons (AAOS) and American Society for Surgery of the Hand (ASSH) websites. Seventy-six patient education articles from the AAOS and ASSH concerning shoulder and elbow disorders were evaluated. Each article was assessed for the number of years since its last update, word count, percentage of passive sentences, Flesch Reading Ease score, Flesch-Kincaid grade level, Simple Measure of Gobbledygook (SMOG) grade, and New Dale-Chall grade level. Only one article was at or below the sixth grade reading level. The AAOS and ASSH articles had the following respective scores: a mean Flesch Reading Ease score of 54.3 and 51.8, Flesch-Kincaid grade level of 9.4 and 10.3, SMOG grade of 8.5 and 9.4, and New Dale-Chall grade of 10.4 and 11.0. Articles from the AAOS were longer (p < 0.001), had a lower percentage of passive sentences (p < 0.001), and were more recently updated (p = 0.02) than their ASSH counterparts. Higher percentages of passive sentences were found to correlate with more difficult readability. Patient education materials regarding the shoulder and elbow on the AAOS and ASSH websites have readability scores above the recommended reading level. These may be too challenging for the majority of patients to read and consequently serve as a barrier to proper patient education. Reducing the percentage of passive sentences may serve as a novel target for improving readability.

Development of seal ring carbon-graphite materials (tasks 8, 9, and 10)

NASA Technical Reports Server (NTRS)

Fechter, N. J.; Petrunich, P. S.

1973-01-01

A screening study was conducted to develop improved carbon-graphite materials for use in self-acting seals at air temperatures to 1300 F (704 C). Property measurements on materials prepared during this study have shown that: (1) The mechanical properties of a carbon-graphite material were significantly improved by using a fine milled artificial graphite filler material and including intensive mixing, warm molding, and pitch impregnation in the processing; and (2) the oxidation resistance of a carbon-graphite material was improved by including fine milled boron carbide as an oxidation-inhibiting additive. These techniques were employed to develop a material that has 10 times more oxidation resistance than that of a widely used commercial grade and mechanical properties that approach those of the commercial grade.

Application of the Materials-by-Design Methodology to Redesign a New Grade of the High-Strength Low-Alloy Class of Steels with Improved Mechanical Properties and Processability

NASA Astrophysics Data System (ADS)

Grujicic, M.; Snipes, J. S.; Ramaswami, S.

2016-01-01

An alternative to the traditional trial-and-error empirical approach for the development of new materials is the so-called materials-by-design approach. Within the latter approach, a material is treated as a complex system and its design and optimization is carried out by employing computer-aided engineering analyses, predictive tools, and available material databases. In the present work, the materials-by-design approach is utilized to redesign a grade of high-strength low-alloy (HSLA) class of steels with improved mechanical properties (primarily strength and fracture toughness), processability (e.g., castability, hot formability, and weldability), and corrosion resistance. Toward that end, a number of material thermodynamics, kinetics of phase transformations, and physics of deformation and fracture computational models and databases have been developed/assembled and utilized within a multi-disciplinary, two-level material-by-design optimization scheme. To validate the models, their prediction is compared against the experimental results for the related steel HSLA100. Then the optimization procedure is employed to determine the optimal chemical composition and the tempering schedule for a newly designed grade of the HSLA class of steels with enhanced mechanical properties, processability, and corrosion resistance.

Costs, Substitution, and Material Use: The Case of Rare Earth Magnets.

PubMed

Smith, Braeton J; Eggert, Roderick G

2018-03-20

Environmental technologies depend on raw materials, some of which are subject to volatile costs and availability concerns. One way to address these concerns is through substitution, of which there are many types. An important form of substitution in the short term is adopting an alternative production process, yielding a material with the same functional properties with less material input. In effect, technology substitutes for material. This study elucidates the role increased and uncertain material costs play in inducing different substitution types in the short to medium term. Specifically, this paper uses an expert survey to determine the relative importance of eight specific industry responses taken by magnet and wind turbine manufacturers in response to the 2010/2011 rare-earth price spike through 2016. Statistical tests show adopting an existing production process for magnets was the most important response, followed by cost passthrough, using an alternate magnet grade in a redesigned generator system, and using alternate systems altogether. The paper also provides specific findings for the magnet and wind turbine industries with respect to each substitution type.

Examining the Reading Level of Internet Medical Information for Common Internal Medicine Diagnoses.

PubMed

Hutchinson, Nora; Baird, Grayson L; Garg, Megha

2016-06-01

The National Institutes of Health (NIH) recommend that health materials be written at a grade 6-7 reading level, which has generally not been achieved in online reading materials. Up to the present time, there have not been any assessments focused on the reading level of online educational materials across the most popular consumer Web sites for common internal medicine diagnoses. In this study, we examined the readability of open-access online health information for 9 common internal medicine diagnoses. Nine of the most frequently encountered inpatient and ambulatory internal medicine diagnoses were selected for analysis. In November and December 2014, these diagnoses were used as search terms in Google, and the top 5 Web sites across all diagnoses and a diagnosis-specific site were analyzed across 5 validated reading indices. On average, the lowest reading grade-level content was provided by the NIH (10.7), followed by WebMD (10.9), Mayo Clinic (11.3), and diagnosis-specific Web sites (11.5). Conversely, Wikipedia provided content that required the highest grade-level readability (14.6). The diagnoses with the lowest reading grade levels were chronic obstructive pulmonary disease (10.8), followed by diabetes (10.9), congestive heart failure (11.7), osteoporosis (11.7) and hypertension (11.7). Depression had the highest grade-level readability (13.8). Despite recommendations for patient health information to be written at a grade 6-7 reading level, our examination of online educational materials pertaining to 9 common internal medicine diagnoses revealed reading levels significantly above the NIH recommendation. This was seen across both diagnosis-specific and general Web sites. There is a need to improve the readability of online educational materials made available to patients. These improvements have the potential to greatly enhance patient awareness, engagement, and physician-patient communication. Published by Elsevier Inc.

A Review of Commercial and Medical-Grade Physiological Monitoring Devices for Biofeedback-Assisted Quality of Life Improvement Studies.

PubMed

Nogueira, Pedro; Urbano, Joana; Reis, Luís Paulo; Cardoso, Henrique Lopes; Silva, Daniel Castro; Rocha, Ana Paula; Gonçalves, Joaquim; Faria, Brígida Mónica

2018-04-17

With the rise in wearable technology and "health culture", we are seeing an increasing interest and affordances in studying how to not only prolong life expectancy but also in how to improve individuals' quality of life. On the one hand, this attempts to give meaning to the increasing life expectancy, as living above a certain threshold of pain and lack of autonomy or mobility is both degrading and unfair. On the other hand, it lowers the cost of continuous care, as individuals with high quality of life indexes tend to have lower hospital readmissions or secondary complications, not to mention higher physical and mental health. In this paper, we evaluate the current state of the art in physiological therapy (biofeedback) along with the existing medical grade and consumer grade hardware for physiological research. We provide a quick primer on the most commonly monitored physiologic metrics, as well as a brief discussion on the current state of the art in biofeedback-assisted medical applications. We then go on to present a comparative analysis between medical and consumer grade biofeedback devices and discuss the hardware specifications and potential practical applications of each consumer grade device in terms of functionality and adaptability for controlled (laboratory) and uncontrolled (field) studies. We end this article with some empirical observations based on our study so that readers might use take them into consideration when arranging a laboratory or real-world experience, thus avoiding costly time delays and material expenditures.

Laser beam welding of new ultra-high strength and supra-ductile steels

NASA Astrophysics Data System (ADS)

Dahmen, Martin

2015-03-01

Ultra-high strength and supra-ductile are entering fields of new applications. Those materials are excellent candidates for modern light-weight construction and functional integration. As ultra-high strength steels the stainless martensitic grade 1.4034 and the bainitic steel UNS 53835 are investigated. For the supra-ductile steels stand two high austenitic steels with 18 and 28 % manganese. As there are no processing windows an approach from the metallurgical base on is required. Adjusting the weld microstructure the Q+P and the QT steels require weld heat treatment. The HSD steel is weldable without. Due to their applications the ultra-high strength steels are welded in as-rolled and strengthened condition. Also the reaction of the weld on hot stamping is reflected for the martensitic grades. The supra-ductile steels are welded as solution annealed and work hardened by 50%. The results show the general suitability for laser beam welding.

Facial Nerve Paralysis after Onyx Embolization of a Jugular Paraganglioma: A Case Report with a Long-Term Follow Up

PubMed Central

Odat, Haitham; Alawneh, Khaled; Al-Qudah, Mohannad

2018-01-01

Jugular paragangliomas are slow growing highly vascular tumors arising from jugular paraganglia. The gold standard of treatment is complete surgical resection. Pre-operative embolization of these highly vascular tumors is essential to reduce intra-operative bleeding, allow safe dissection, and decrease operative time and post-operative complications. Onyx (ethylene-vinyl alcohol copolymer) has been widely used as permanent occluding material for vascular tumors of skull base because of its unique physical properties. We present the case of a 33-year-old woman who had left-sided facial nerve paralysis after Onyx embolization of jugular paraganglioma. The tumor was resected on the next day of embolization. The patient was followed up for 30 months with serial imaging studies and facial nerve assessment. The facial verve function improved from House–Brackmann grade V to grade II at the last visit. PMID:29518926

Facial Nerve Paralysis after Onyx Embolization of a Jugular Paraganglioma: A Case Report with a Long-Term Follow Up.

PubMed

Odat, Haitham; Alawneh, Khaled; Al-Qudah, Mohannad

2018-03-07

Jugular paragangliomas are slow growing highly vascular tumors arising from jugular paraganglia. The gold standard of treatment is complete surgical resection. Pre-operative embolization of these highly vascular tumors is essential to reduce intra-operative bleeding, allow safe dissection, and decrease operative time and post-operative complications. Onyx (ethylene-vinyl alcohol copolymer) has been widely used as permanent occluding material for vascular tumors of skull base because of its unique physical properties. We present the case of a 33-year-old woman who had left-sided facial nerve paralysis after Onyx embolization of jugular paraganglioma. The tumor was resected on the next day of embolization. The patient was followed up for 30 months with serial imaging studies and facial nerve assessment. The facial verve function improved from House-Brackmann grade V to grade II at the last visit.

MATERIALS USED IN TEACHING AND EVALUATING THE CONCEPTS RELATED TO THE BIOLOGICAL CELL IN GRADES 2-6, PRACTICAL PAPER NO. 2.

ERIC Educational Resources Information Center

STAUSS, NYLES G.

INCLUDED ARE MATERIALS FOR USE IN TEACHING AND EVALUATING 11 SELECTED CONCEPTS RELATED TO THE BIOLOGICAL CELL IN GRADES 2 TO 6. THE CONCEPTS WERE SELECTED AND THEIR ORDER DETERMINED THROUGH AN ANALYSIS OF ELEMENTARY TEXTBOOK SERIES, HIGH SCHOOL AND COLLEGE BIOLOGY TEXTS, CYTOLOGY TEXTS, AND INFORMATION GATHERED THROUGH A PILOT STUDY. THE MATERIALS…

The Effects of Content-Area Writing Patterns Upon Cue System Utilization by Second-Grade, Ninth-Grade, and Mature Adult Readers.

ERIC Educational Resources Information Center

Stansell, John C.; And Others

Studies were conducted to investigate cue system utilization by three groups of readers--six second graders, six ninth graders, and four adults past the age of sixty who were rated as mature readers. The second graders read materials that varied according to organizational structure, while the other groups read materials that differed in the…

Gender-Based Content of Educational Materials for the Study of Serbian Language in Lower-Stage Grades of Elementary Education

ERIC Educational Resources Information Center

Trifunovic, Vesna; Petrovic, Ruzica

2014-01-01

This paper presents the results of analysis of educational materials for the study of Serbian language in lower-stage grades of elementary education (intended for students from 7 through 11 years old) from gender perspective. The first part of the paper presents the process of institutionalization of gender-based education in the Republic of…

Interdisciplinary Student/Teacher Materials in Energy, the Environment, and the Economy: 6, The Energy We Use, Grade 1.

ERIC Educational Resources Information Center

Bloch, Lenore; And Others

This instructional unit contains a set of nine lessons on energy for grade one. Each lesson contains complete teacher and student materials. Reading skills and language experiences are reinforced in each activity. The lessons cover such topics as energy from food, energy from the sun, fossil fuels, the wind, moving water, and energy conservation.…

The Minnesota Project English Center: Selected Materials. Unit 701: Introduction to the Study of Language.

ERIC Educational Resources Information Center

Minnesota Univ., Minneapolis. Center for Curriculum Development in English.

This Minnesota Curriculum Center report recounts the development of teaching materials on the nature and uses of language for grades 7-12 and presents the first of five seventh-grade units. A description of the origins, purposes, and personnel of the Center is followed by brief discussions of (1) the Center's underlying assumption that a study of…

Serving the Community. Lawyers Helping Young People Become Good Citizens. I'm the People--It's about Citizenship and You.

ERIC Educational Resources Information Center

American Bar Association, Chicago, IL. Special Committee on Youth Education for Citizenship.

Organized around the theme of community service, this booklet provides teachers and lawyers with classroom materials for elementary grades K-3 (Level A), intermediate grades 4-6 (Level B), middle school grades 6-8 (Level C), and high school grades 9-12 (Level D). In addition, each level contains pages for the lawyer (marked by the scales of…

A Computer Vision System forAnalyzing Images of Rough Hardwood Lumber

Treesearch

Tai-Hoon Cho; Richard W. Conners; Philip A. Araman

1990-01-01

A sawmill cuts logs into lumber and sells this lumber to secondary remanufacturers. The price a sawmiller can charge for a volume of lumber depends on its grade. For a number of species the price of a given volume of material can double in going from one grade to the next higher grade. While the grade of a board largely depends on the distribution of defects on the...

Social Studies Curriculum Guide: Grade 5.

ERIC Educational Resources Information Center

Dependents Schools (DOD), Washington, DC.

An outline of the knowledge and skills to be taught at grade five in order to meet the Department of Defense Dependents Schools (DoDDS) social studies objectives is provided. Material is divided into four parts. Following an introduction, a one page description overviews the curriculum topic for grade five, American geography and government, and…

Social Studies Curriculum Guide: Grade 8.

ERIC Educational Resources Information Center

Dependents Schools (DOD), Washington, DC.

An outline of the knowledge and skills to be taught at grade eight in order to meet the Department of Defense Dependents Schools (DoDDS) social studies objectives is provided. Material is divided into three parts. Following an introduction, a one page description overviews the curriculum topic for grade eight, United States history, and specifies…

Social Studies Curriculum Guide: Grade 6.

ERIC Educational Resources Information Center

Dependents Schools (DOD), Washington, DC.

An outline of the knowledge and skills to be taught at grade six in order to meet the Department of Defense Dependents Schools (DoDDS) social studies objectives is provided. Material is divided into four parts. Following an introduction, a one page description overviews the curriculum topic for grade six, world cultures and geography, and…

Social Studies Program Guide, 3-6: Intermediate Grades.

ERIC Educational Resources Information Center

Spokane School District 81, WA.

This curriculum guide suggests materials, resources, and activities related to social studies knowledge and skill development for grades 4-6. Third grade activities are also included to inform intermediate teachers what has been previously taught. Part of a series of social studies program guides designed to be used in the Spokane public schools…

Art. Elementary Teacher Resource, 1985.

ERIC Educational Resources Information Center

Alberta Dept. of Education, Edmonton.

Designed to accompany the "Elementary Art Curriculum Guide," this resource is divided into 3 levels: level 1 grades 1-2, level 2 grades 3-4, and level 3 grades 5-6. The material is presented in a standardized format which includes four major components: reflection, depiction, composition, and expression. Once a concept has been chosen,…

Career Activities in Science: Grades 7, 8, 9.

ERIC Educational Resources Information Center

Boise City Independent School District, ID.

The career activities guide in science, part of an Idaho State Department of Vocational Education career exploration series for grades 7, 8, and 9, is designed as supplementary material to enrich the regular curriculum. Any one activity in the guide might be used without involving any other activities. The cross-referenced index indicates grades,…

Strand V: Education for Survival. First Aid and Survival Education. Health Curriculum Materials Grades 10-12.

ERIC Educational Resources Information Center

New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

GRADES OR AGES: Grades 10-12. SUBJECT MATTER: First aid and survival education. ORGANIZATION AND PHYSICAL APPEARANCE: The guide is divided into six sections: transportation of the injured, automobile accidents, conditions resulting from nuclear explosion, chemical warfare, natural catastrophes, and psychological first aid. The publication format…

The Need for a Core, Interdisciplinary, Life-Sciences Curriculum in the Middle Grades.

ERIC Educational Resources Information Center

Heller, H. Craig

1993-01-01

Campaigns to improve adolescent health must involve schools, focusing on middle grades. Currently, school organization is poor, with too little good curricular material for such students. The article describes Stanford University's interdisciplinary, core, middle grades curriculum in human biology that combats alienation from science by making it…

School Violence and the Law.

ERIC Educational Resources Information Center

Kopecky, Frank

Organized around the theme of school violence, this booklet provides teachers and lawyers with classroom materials for elementary grades 4-6 (Level A), intermediate grades 6-8 (Level B), and high school grades 9-12 (Level C). In addition, each level contains pages for the lawyer (marked by the scales of justice), the teacher (an apple), and the…

Solid Waste/Energy Curriculum.

ERIC Educational Resources Information Center

Vivan, V. Eugene; And Others

Provided are solid waste/energy curriculum materials for grades K-2, 3-4, 5-6, 7-9, and 10-12. Separate folders containing units of study (focusing on trash, litter, and recycling) are provided for kindergarten (four units), grade 1 (two units), and grade 2 (two units). Folders contain teachers' directions and activity cards which include picture…

Instructional Materials on Africa for Primary Grades. An Instructional Unit for Grade One.

ERIC Educational Resources Information Center

Smith, Allie Evelyn

Focusing on traditional African families, villages, and cultures, this teaching guide presents objectives, activities, resources, and evaluation suggestions for use in grade one social studies African area programs. The instructional guide is a product of a summer workshop for teachers on African curriculum development. It is intended as the basis…

Materials science. Assembly of micro/nanomaterials into complex, three-dimensional architectures by compressive buckling.

PubMed

Xu, Sheng; Yan, Zheng; Jang, Kyung-In; Huang, Wen; Fu, Haoran; Kim, Jeonghyun; Wei, Zijun; Flavin, Matthew; McCracken, Joselle; Wang, Renhan; Badea, Adina; Liu, Yuhao; Xiao, Dongqing; Zhou, Guoyan; Lee, Jungwoo; Chung, Ha Uk; Cheng, Huanyu; Ren, Wen; Banks, Anthony; Li, Xiuling; Paik, Ungyu; Nuzzo, Ralph G; Huang, Yonggang; Zhang, Yihui; Rogers, John A

2015-01-09

Complex three-dimensional (3D) structures in biology (e.g., cytoskeletal webs, neural circuits, and vasculature networks) form naturally to provide essential functions in even the most basic forms of life. Compelling opportunities exist for analogous 3D architectures in human-made devices, but design options are constrained by existing capabilities in materials growth and assembly. We report routes to previously inaccessible classes of 3D constructs in advanced materials, including device-grade silicon. The schemes involve geometric transformation of 2D micro/nanostructures into extended 3D layouts by compressive buckling. Demonstrations include experimental and theoretical studies of more than 40 representative geometries, from single and multiple helices, toroids, and conical spirals to structures that resemble spherical baskets, cuboid cages, starbursts, flowers, scaffolds, fences, and frameworks, each with single- and/or multiple-level configurations. Copyright © 2015, American Association for the Advancement of Science.

Specific Features of After-School Program Quality: Associations with Children’s Functioning in Middle Childhood

PubMed Central

Bolt, Daniel M.; Vandell, Deborah Lowe

2010-01-01

This longitudinal study examined associations between three after-school program quality features (positive staff–child relations, available activities, programming flexibility) and child developmental outcomes (reading and math grades, work habits, and social skills with peers) in Grade 2 and then Grade 3. Participants (n = 120 in Grade 2, n = 91 in Grade 3) attended after-school programs more than 4 days per week, on average. Controlling for child and family background factors and children’s prior functioning on the developmental outcomes, positive staff–child relations in the programs were positively associated with children’s reading grades in both Grades 2 and 3, and math grades in Grade 2. Positive staff–child relations also were positively associated with social skills in Grade 2, for boys only. The availability of a diverse array of age-appropriate activities at the programs was positively associated with children’s math grades and classroom work habits in Grade 3. Programming flexibility (child choice of activities) was not associated with child outcomes. PMID:20336364

Tantalum Addition to Zirconium Diboride for Improved Oxidation Resistance

NASA Technical Reports Server (NTRS)

Levine, Stanley R.; Opila, Eliizabeth J.

2003-01-01

Ultrahigh temperature ceramics have performed unreliably due to material flaws and attachment design. These deficiencies are brought to the fore by the low fracture toughness and thermal shock resistance of UHTCs. If these deficiencies are overcome, we are still faced with poor oxidation resistance as a limitation on UHTC applicability to reusable launch vehicles. We have been addressing the deficiencies of UHTCs with our focus on composite constructions and functional grading to address the mechanical issues, and on composition modification to address the oxidation issue. The approaches and progress toward the latter are reported.

Plasmids from Food Lactic Acid Bacteria: Diversity, Similarity, and New Developments

PubMed Central

Cui, Yanhua; Hu, Tong; Qu, Xiaojun; Zhang, Lanwei; Ding, Zhongqing; Dong, Aijun

2015-01-01

Plasmids are widely distributed in different sources of lactic acid bacteria (LAB) as self-replicating extrachromosomal genetic materials, and have received considerable attention due to their close relationship with many important functions as well as some industrially relevant characteristics of the LAB species. They are interesting with regard to the development of food-grade cloning vectors. This review summarizes new developments in the area of lactic acid bacteria plasmids and aims to provide up to date information that can be used in related future research. PMID:26068451

Surface protection in bio-shields via a functional soft skin layer: Lessons from the turtle shell.

PubMed

Shelef, Yaniv; Bar-On, Benny

2017-09-01

The turtle shell is a functional bio-shielding element, which has evolved naturally to provide protection against predator attacks that involve biting and clawing. The near-surface architecture of the turtle shell includes a soft bi-layer skin coating - rather than a hard exterior - which functions as a first line of defense against surface damage. This architecture represents a novel type of bio-shielding configuration, namely, an inverse structural-mechanical design, rather than the hard-coated bio-shielding elements identified so far. In the current study, we used experimentally based structural modeling and FE simulations to analyze the mechanical significance of this unconventional protection architecture in terms of resistance to surface damage upon extensive indentations. We found that the functional bi-layer skin of the turtle shell, which provides graded (soft-softer-hard) mechanical characteristics to the bio-shield exterior, serves as a bumper-buffer mechanism. This material-level adaptation protects the inner core from the highly localized indentation loads via stress delocalization and extensive near-surface plasticity. The newly revealed functional bi-layer coating architecture can potentially be adapted, using synthetic materials, to considerably enhance the surface load-bearing capabilities of various engineering configurations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Readability, content, and quality of online patient education materials on preeclampsia.

PubMed

Lange, Elizabeth M S; Shah, Anuj M; Braithwaite, Brian A; You, Whitney B; Wong, Cynthia A; Grobman, William A; Toledo, Paloma

2015-01-01

The objective of this study was to evaluate the readability, content, and quality of patient education materials addressing preeclampsia. Websites of U.S. obstetrics and gynecology residency programs were searched for patient education materials. Readability, content, and quality were assessed. A one-sample t-test was used to evaluate mean readability level compared with the recommended 6th grade reading level. Mean readability levels were higher using all indices (p < 0.001). Content was variable with good website understandability, but poor actionability. The mean readability was above the recommended 6th grade reading level. The content, readability, and actionability of preeclampsia patient education materials should be improved.

A Review on Electroactive Polymers for Waste Heat Recovery.

PubMed

Kolasińska, Ewa; Kolasiński, Piotr

2016-06-17

This paper reviews materials for thermoelectric waste heat recovery, and discusses selected industrial and distributed waste heat sources as well as recovery methods that are currently applied. Thermoelectric properties, especially electrical conductivity, thermopower, thermal conductivity and the thermoelectric figures of merit, are considered when evaluating thermoelectric materials for waste heat recovery. Alloys and oxides are briefly discussed as materials suitable for medium- and high-grade sources. Electroactive polymers are presented as a new group of materials for low-grade sources. Polyaniline is a particularly fitting polymer for these purposes. We also discuss types of modifiers and modification methods, and their influence on the thermoelectric performance of this class of polymers.

Radical Vernacular: Bacterial Architecture on Mars

NASA Astrophysics Data System (ADS)

Dade-Robertson, M.; Ramirez-Figueroa, C.; Zhang, M.

Our current speculative discourse on the colonisation of other planets tends to consider future buildings through the lens of hitech architecture. However, we suggest that developments in biotechnology will enable types of construction which are beyond even our current science fictions. The paper presents an argument for bioengineered building materials framed by the notion of constructing buildings on Mars. It introduces the concept of biomineralisation and its processes and applications, and focuses on the creation of calcium carbonate by certain strains of bacteria. We will suggest that by utilising this process in conjunction with synthetic biology (where bacteria are engineered to survive and respond to the environment on other planets) a building process emerges where the materials are adaptive and, to some extent, self-constructed in relation to their environments. The paper concludes by speculating about a building process involving the use of bioengineered bacteria to consolidate materials, found on the surface of Mars, to create materials and structures which are functionally graded.

Constitutive law for thermally-activated plasticity of recrystallized tungsten

NASA Astrophysics Data System (ADS)

Zinovev, Aleksandr; Terentyev, Dmitry; Dubinko, Andrii; Delannay, Laurent

2017-12-01

A physically-based constitutive law relevant for ITER-specification tungsten grade in as-recrystallized state is proposed. The material demonstrates stages III and IV of the plastic deformation, in which hardening rate does not drop to zero with the increase of applied stress. Despite the classical Kocks-Mecking model, valid at stage III, the strain hardening asymptotically decreases resembling a hyperbolic function. The material parameters are fitted by relying on tensile test data and by requiring that the strain and stress at the onset of diffuse necking (uniform elongation and ultimate tensile strength correspondingly) as well as the yield stress be reproduced. The model is then validated in the temperature range 300-600 °C with the help of finite element analysis of tensile tests which confirms the reproducibility of the experimental engineering curves up to the onset of diffuse necking, beyond which the development of ductile damage accelerates the material failure. This temperature range represents the low temperature application window for tungsten as divertor material in fusion reactor ITER.

Structural kinematics based damage zone prediction in gradient structures using vibration database

NASA Astrophysics Data System (ADS)

Talha, Mohammad; Ashokkumar, Chimpalthradi R.

2014-05-01

To explore the applications of functionally graded materials (FGMs) in dynamic structures, structural kinematics based health monitoring technique becomes an important problem. Depending upon the displacements in three dimensions, the health of the material to withstand dynamic loads is inferred in this paper, which is based on the net compressive and tensile displacements that each structural degree of freedom takes. These net displacements at each finite element node predicts damage zones of the FGM where the material is likely to fail due to a vibration response which is categorized according to loading condition. The damage zone prediction of a dynamically active FGMs plate have been accomplished using Reddy's higher-order theory. The constituent material properties are assumed to vary in the thickness direction according to the power-law behavior. The proposed C0 finite element model (FEM) is applied to get net tensile and compressive displacement distributions across the structures. A plate made of Aluminum/Ziconia is considered to illustrate the concept of structural kinematics-based health monitoring aspects of FGMs.

Calculation and word problem-solving skills in primary grades - Impact of cognitive abilities and longitudinal interrelations with task-persistent behaviour.

PubMed

Jõgi, Anna-Liisa; Kikas, Eve

2016-06-01

Primary school math skills form a basis for academic success down the road. Different math skills have different antecedents and there is a reason to believe that more complex math tasks require better self-regulation. The study aimed to investigate longitudinal interrelations of calculation and problem-solving skills, and task-persistent behaviour in Grade 1 and Grade 3, and the effect of non-verbal intelligence, linguistic abilities, and executive functioning on math skills and task persistence. Participants were 864 students (52.3% boys) from 33 different schools in Estonia. Students were tested twice - at the end of Grade1 and at the end of Grade 3. Calculation and problem-solving skills, and teacher-rated task-persistent behaviour were measured at both time points. Non-verbal intelligence, linguistic abilities, and executive functioning were measured in Grade 1. Cross-lagged structural equation modelling indicated that calculation skills depend on previous math skills and linguistic abilities, while problem-solving skills require also non-verbal intelligence, executive functioning, and task persistence. Task-persistent behaviour in Grade 3 was predicted by previous problem-solving skills, linguistic abilities, and executive functioning. Gender and mother's educational level were added as covariates. The findings indicate that math skills and self-regulation are strongly related in primary grades and that solving complex tasks requires executive functioning and task persistence from children. Findings support the idea that instructional practices might benefit from supporting self-regulation in order to gain domain-specific, complex skill achievement. © 2015 The British Psychological Society.

Boundary element method for normal non-adhesive and adhesive contacts of power-law graded elastic materials

NASA Astrophysics Data System (ADS)

Li, Qiang; Popov, Valentin L.

2018-03-01

Recently proposed formulation of the boundary element method for adhesive contacts has been generalized for contacts of power-law graded materials with and without adhesion. Proceeding from the fundamental solution for single force acting on the surface of an elastic half space, first the influence matrix is obtained for a rectangular grid. The inverse problem for the calculation of required stress in the contact area from a known surface displacement is solved using the conjugate-gradient technique. For the transformation between the stresses and displacements, the Fast Fourier Transformation is used. For the adhesive contact of graded material, the detachment criterion based on the energy balance is proposed. The method is validated by comparison with known exact analytical solutions as well as by proving the independence of the mesh size and the grid orientation.

Laser Scribed Graphene Biosensor for Detection of Biogenic Amines in Food Samples Using Locally Sourced Materials.

PubMed

Vanegas, Diana C; Patiño, Laksmi; Mendez, Connie; Oliveira, Daniela Alves de; Torres, Alba M; Gomes, Carmen L; McLamore, Eric S

2018-04-24

In foods, high levels of biogenic amines (BA) are the result of microbial metabolism that could be affected by temperatures and storage conditions. Thus, the level of BA is commonly used as an indicator of food safety and quality. This manuscript outlines the development of laser scribed graphene electrodes, with locally sourced materials, for reagent-free food safety biosensing. To fabricate the biosensors, the graphene surface was functionalized with copper microparticles and diamine oxidase, purchased from a local supermarket; and then compared to biosensors fabricated with analytical grade materials. The amperometric biosensor exhibits good electrochemical performance, with an average histamine sensitivity of 23.3 µA/mM, a lower detection limit of 11.6 µM, and a response time of 7.3 s, showing similar performance to biosensors constructed from analytical grade materials. We demonstrated the application of the biosensor by testing total BA concentration in fish paste samples subjected to fermentation with lactic acid bacteria. Biogenic amines concentrations prior to lactic acid fermentation were below the detection limit of the biosensor, while concentration after fermentation was 19.24 ± 8.21 mg histamine/kg, confirming that the sensor was selective in a complex food matrix. The low-cost, rapid, and accurate device is a promising tool for biogenic amine estimation in food samples, particularly in situations where standard laboratory techniques are unavailable, or are cost prohibitive. This biosensor can be used for screening food samples, potentially limiting food waste, while reducing chances of foodborne outbreaks.

Functionally graded biomimetic energy absorption concept development for transportation systems.

DOT National Transportation Integrated Search

2014-02-01

Mechanics of a functionally graded cylinder subject to static or dynamic axial loading is considered, including a potential application as energy absorber. The mass density and stiffness are power functions of the radial coordinate as may be the case...

Tissue-Specific Analysis of Secondary Metabolites Creates a Reliable Morphological Criterion for Quality Grading of Polygoni Multiflori Radix.

PubMed

Liang, Li; Xu, Jun; Liang, Zhi-Tao; Dong, Xiao-Ping; Chen, Hu-Biao; Zhao, Zhong-Zhen

2018-05-08

In commercial herbal markets, Polygoni Multiflori Radix (PMR, the tuberous roots of Polygonum multiflorum Thunb.), a commonly-used Chinese medicinal material, is divided into different grades based on morphological features of size and weight. While more weight and larger size command a higher price, there is no scientific data confirming that the more expensive roots are in fact of better quality. To assess the inherent quality of various grades and of various tissues in PMR and to find reliable morphological indicators of quality, a method combining laser microdissection (LMD) and ultra-performance liquid chromatography triple-quadrupole mass spectrometry (UPLC-QqQ-MS/MS) was applied. Twelve major chemical components were quantitatively determined in both whole material and different tissues of PMR. Determination of the whole material revealed that traditional commercial grades based on size and weight of PRM did not correspond to any significant differences in chemical content. Instead, tissue-specific analysis indicated that the morphological features could be linked with quality in a new way. That is, PMR with broader cork and phloem, as seen in a transverse section, were typically of better quality as these parts are where the bioactive components accumulate. The tissue-specific analysis of secondary metabolites creates a reliable morphological criterion for quality grading of PMR.

Learning Science in Grades 3 8 Using Probeware and Computers: Findings from the TEEMSS II Project

NASA Astrophysics Data System (ADS)

Zucker, Andrew A.; Tinker, Robert; Staudt, Carolyn; Mansfield, Amie; Metcalf, Shari

2008-02-01

The Technology Enhanced Elementary and Middle School Science II project (TEEMSS), funded by the National Science Foundation, produced 15 inquiry-based instructional science units for teaching in grades 3-8. Each unit uses computers and probeware to support students' investigations of real-world phenomena using probes (e.g., for temperature or pressure) or, in one case, virtual environments based on mathematical models. TEEMSS units were used in more than 100 classrooms by over 60 teachers and thousands of students. This paper reports on cases in which groups of teachers taught science topics without TEEMSS materials in school year 2004-2005 and then the same teachers taught those topics using TEEMSS materials in 2005-2006. There are eight TEEMSS units for which such comparison data are available. Students showed significant learning gains for all eight. In four cases (sound and electricity, both for grades 3-4; temperature, grades 5-6; and motion, grades 7-8) there were significant differences in science learning favoring the students who used the TEEMSS materials. The effect sizes are 0.58, 0.94, 1.54, and 0.49, respectively. For the other four units there were no significant differences in science learning between TEEMSS and non-TEEMSS students. We discuss the implications of these results for science education.

The readability of American Academy of Pediatrics patient education brochures.

PubMed

Freda, Margaret Comerford

2005-01-01

The purpose of this study was to evaluate the readability of American Academy of Pediatrics (AAP) patient education brochures. Seventy-four brochures were analyzed using two readability formulas. Mean readability for all 74 brochures was grade 7.94 using the Flesch-Kincaid formula, and grade 10.1 with SMOG formula (P = .001). Using the SMOG formula, no brochures were of acceptably low (< or =8th grade) readability levels (range 8.3 to 12.7). Using the Flesch-Kincaid formula, 41 of the 74 had acceptable readability levels (< or =8th grade). The SMOG formula routinely assessed brochures 2 to 3 grade levels higher than did the Flesch-Kincaid formula. Some AAP patient education brochures have acceptably low levels of readability, but at least half are written at higher than acceptable readability levels for the general public. This study also demonstrated statistically significant variability between the two different readability formulas; had only the SMOG formula been used, all of the brochures would have had unacceptably high readability levels. Readability is an essential concept for patient education materials. Professional associations that develop and market patient education materials should test for readability and publish those readability levels on each piece of patient education so health care providers will know if the materials are appropriate for their patients.