Science.gov

Sample records for negative-index material design

  1. Negative index materials using simple short wire pairs

    NASA Astrophysics Data System (ADS)

    Zhou, Jiangfeng; Zhang, Lei; Tuttle, Gary; Koschny, Thomas; Soukoulis, Costas M.

    2006-01-01

    Negative refraction is currently achieved by a combination of artificial “electric atoms” (metallic wires with negative electrical permittivity ? ) and artificial “magnetic atoms” (split-ring resonators with negative magnetic permeability ? ). Both ? and ? must be negative at the same frequency, which is not easy to achieve at higher than THz frequencies. We introduce improved and simplified structures made of periodic arrays of pairs of short metal wires and continuous wires that offer a potentially simpler approach to building negative index materials. Using simulations and microwave experiments, we have investigated the negative index n properties of short wire-pair structures. We have measured experimentally both the transmittance and the reflectance properties and found unambiguously that n<0 . The same is true for ? and ? . Our results show that short wire-pair arrays can be used very effectively in producing materials with negative refractive indices.

  2. Role of the anomalous self-steepening effect in modulation instability in negative-index material.

    PubMed

    Wen, Shuangchun; Xiang, Yuanjiang; Su, Wenhua; Hu, Yonghua; Fu, Xiquan; Fan, Dianyuan

    2006-02-20

    In negative-index materials (NIMs), the self-steepening (SS) effect is proven to be anomalous in two aspects: First, it can be either positive or negative, with the zero SS point determined by the size of split-ring resonator circuit elements. Second, the negative SS parameter can have a very large value compared to an ordinary positive-index material. We present a theoretical investigation on modulation instability (MI) to identify the role of the anomalous SS effect in NIM. We find that the first anomaly of SS doesn't influence MI, yet the controllable zero SS point can be used to manipulate MI, and thus manipulate the generation of solitons. The second anomaly, however, leads to significant changes in the MI condition and property, compared with the case of an ordinary positive-index material. Numerical simulations confirm the theoretical results and show that negative SS moves the center of generated pulse toward the leading side, and shifts a part of energy of the generated pulse toward the red side, opposite to the case of positive SS. PMID:19503483

  3. Backward phase-matching for nonlinear optical generation in negative-index materials

    NASA Astrophysics Data System (ADS)

    Lan, Shoufeng; Kang, Lei; Schoen, David T.; Rodrigues, Sean P.; Cui, Yonghao; Brongersma, Mark L.; Cai, Wenshan

    2015-08-01

    Metamaterials have enabled the realization of unconventional electromagnetic properties not found in nature, which provokes us to rethink the established rules of optics in both the linear and nonlinear regimes. One of the most intriguing phenomena in nonlinear metamaterials is `backward phase-matching', which describes counter-propagating fundamental and harmonic waves in a negative-index medium. Predicted nearly a decade ago, this process is still awaiting a definitive experimental confirmation at optical frequencies. Here, we report optical measurements showing backward phase-matching by exploiting two distinct modes in a nonlinear plasmonic waveguide, where the real parts of the mode refractive indices are 3.4 and -3.4 for the fundamental and the harmonic waves respectively. The observed peak conversion efficiency at the excitation wavelength of ~780 nm indicates the fulfilment of the phase-matching condition of k2? = 2k? and n2? = -n?, where the coherent harmonic wave emerges along a direction opposite to that of the incoming fundamental light.

  4. Structures with negative index of refraction

    DOEpatents

    Soukoulis, Costas M. (Ames, IA); Zhou, Jiangfeng (Ames, IA); Koschny, Thomas (Ames, IA); Zhang, Lei (Ames, IA); Tuttle, Gary (Ames, IA)

    2011-11-08

    The invention provides simplified negative index materials (NIMs) using wire-pair structures, 4-gap single ring split-ring resonator (SRR), fishnet structures and overleaf capacitor SRR. In the wire-pair arrangement, a pair of short parallel wires and continuous wires are used. In the 4-gap single-ring SRR, the SRRs are centered on the faces of a cubic unit cell combined with a continuous wire type resonator. Combining both elements creates a frequency band where the metamaterial is transparent with simultaneously negative .di-elect cons. and .mu.. In the fishnet structure, a metallic mesh on both sides of the dielectric spacer is used. The overleaf capacitor SRR changes the gap capacities to small plate capacitors by making the sections of the SRR ring overlap at the gaps separated by a thin dielectric film. This technique is applicable to conventional SRR gaps but it best deploys for the 4-gap single-ring structures.

  5. Active negative-index metamaterial powered by an electron beam

    E-print Network

    Shapiro, Michael

    An active negative index metamaterial that derives its gain from an electron beam is introduced. The metamaterial consists of a stack of equidistant parallel metal plates perforated by a periodic array of holes shaped as ...

  6. Optical multistability in nonlinear negative index Fibonacci multilayers

    NASA Astrophysics Data System (ADS)

    Xu, Guoding; Pan, Tao; Zang, Taocheng; Sun, Jian

    2008-07-01

    We have demonstrated numerically that the nonlinear negative index Fibonacci multilayer can exhibit optical multistability and offer a wide variety of switching between states of various contrasts. The stepwise up-switch and one-step or stepwise down-switch operations can take place in such structures. It is also shown that multistable operations and contrasts can be controlled by regulating the width of the negative index slabs.

  7. Tunable Metallic Photonic Crystals with an Effective Negative Index of Refraction

    E-print Network

    Mojahedi, Mohammad

    Tunable Metallic Photonic Crystals with an Effective Negative Index of Refraction Mark S. Wheeler The design of negative refractive index (NRI) metamaterials is an exciting field of research, even though metamaterials [2-4]. Although in general PCs can produce "negative refraction" with and without BW behavior

  8. Robust wedge demonstration to optical negative index metamaterials Nian-Hai Shen,1,a)

    E-print Network

    ://dx.doi.org/10.1063/1.4812240] Nowadays, metamaterials (MMs) have been well-known in a variety of scientific, etc.1­8 To flexibly program the designs of MMs for objective applications, the characterization of MMs, based on Snell's Law. Since the beginning of the field of MMs, the study of negative index metamaterials

  9. Negative refraction without negative index in metallic photonic crystals

    E-print Network

    Negative refraction without negative index in metallic photonic crystals Chiyan Luo, Steven G: It is shown that certain metallic photonic crystals can enable negative refraction and subwavelength imaging negative values of and µ," Sov. Phys. Usp. 10, 509-514 (1968). 5. J. B. Pendry, "Negative refraction makes

  10. Wave packet propagation into a negative index medium

    NASA Astrophysics Data System (ADS)

    Huang, Xiaobiao; Schaich, W. L.

    2004-09-01

    We examine the phenomenon of negative refraction using wave packet propagation. The behavior of a single plane wave incident from vacuum onto a flat surface of a medium with a negative index of refraction is solved analytically. The solution requires matching electromagnetic field components across the interface and produces a reflected and a refracted wave in addition to the incident wave. We form by numerical integration a (Gaussian-weighted) linear combination of these solutions. Pictures and videos that illustrate the resulting wave packet motion are presented for a variety of parameter choices.

  11. Intra-connected three-dimensionally isotropic bulk negative index photonic metamaterial

    SciTech Connect

    Guney, Durdu; Koschny, Thomas; Soukoulis, Costas

    2010-05-26

    Isotropic negative index metamaterials (NIMs) are highly desired, particularly for the realization of ultra-high resolution lenses. However, existing isotropic NIMs function only two-dimensionally and cannot be miniaturized beyond microwaves. Direct laser writing processes can be a paradigm shift toward the fabrication of three-dimensionally (3D) isotropic bulk optical metamaterials, but only at the expense of an additional design constraint, namely connectivity. Here, we demonstrate with a proof-of-principle design that the requirement connectivity does not preclude fully isotropic left-handed behavior. This is an important step towards the realization of bulk 3D isotropic NIMs at optical wavelengths.

  12. Negative index of refraction in a four-level system with magnetoelectric cross coupling and local field corrections

    SciTech Connect

    Bello, F.

    2011-07-15

    This research focuses on a coherently driven four-level atomic medium with the aim of inducing a negative index of refraction while taking into consideration local field corrections as well as magnetoelectric cross coupling (i.e.,chirality) within the material's response functions. Two control fields are used to render the medium transparent for a probe field which simultaneously couples to an electric and a magnetic dipole transition, thus allowing one to test the permittivity and permeability of the material at the same time. Numerical simulations show that a negative index of refraction with low absorption can be obtained for a range of probe detunings while depending on number density and the ratio between the intensities of the control fields.

  13. Designing Printed Instructional Materials.

    ERIC Educational Resources Information Center

    Burbank, Lucille; Pett, Dennis

    1986-01-01

    Discusses the importance of identifying the audience and determining specific objectives when designing printed instructional materials that will communicate effectively and provides detailed guidelines for dealing with such design factors as content, writing style, typography, illustrations, and page organization. (MBR)

  14. Relationship between the Kramers-Kronig relations and negative index of refraction

    E-print Network

    Hickey, Mark C; Kussow, Adil-Gerai

    2010-01-01

    The condition for a negative index of refraction with respect to the vacuum index is established in terms of permittivity and permeability susceptibilities. It is found that the imposition of analyticity to satisfy the Kramers-Kronig relations is a sufficiently general criterion for a physical negative index. The satisfaction of the Kramers-Kronig relations is a manifestation of the principle of causality and the predicted frequency region of negative index agrees with the Depine-Lakhtakia condition for the phase velocity being anti-directed to the Poynting vector, although the conditions presented here do not assume {\\it a priori} a negative solution branch for n.

  15. Relationship between the Kramers-Kronig relations and negative index of refraction

    SciTech Connect

    Akyurtlu, Alkim; Kussow, Adil-Gerai

    2010-11-15

    The condition for a negative index of refraction with respect to the vacuum index is established in terms of permittivity and permeability susceptibilities. It is found that the imposition of analyticity to satisfy the Kramers-Kronig relations is a sufficiently general criterion for a physical negative index. The satisfaction of the Kramers-Kronig relations is a manifestation of the principle of causality and the predicted frequency region of negative index agrees with the Depine-Lakhtakia condition for the phase velocity being antidirected to the Poynting vector, although the conditions presented here do not assume a priori a negative solution branch for n.

  16. Design a Sculpting Material

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2011-01-01

    Artists have used a variety of materials over the years for sculpting. They have been quick to use unusual pieces of technology to make a vibrant and unique statement, just as painters have created and used a wide variety of colors and derived pigments for their canvases. In this article, the author discusses a design challenge that gives students…

  17. Negative index short-slab pair and continuous wires metamaterials in the far infrared regime

    E-print Network

    Negative index short-slab pair and continuous wires metamaterials in the far infrared regime T. F-USDOE, and Department of Physics and Astronomy, Iowa State University, Ames, Iowa, 50011, USA 4 Science Department procedure, we demonstrate the occurrence of a negative refractive index regime in the far infrared range, ~2

  18. Material-based design computation

    E-print Network

    Oxman, Neri

    2010-01-01

    The institutionalized separation between form, structure and material, deeply embedded in modernist design theory, paralleled by a methodological partitioning between modeling, analysis and fabrication, resulted in ...

  19. Low loss negative index metamaterials with one type of meta-atom

    NASA Astrophysics Data System (ADS)

    Kanté, Boubacar; de Lustrac, André; Lourtioz, Jean-Michel

    2010-05-01

    Metamaterial building blocks from microwave to optical range are mainly based on metal-dielectric composites. In almost all structures with true negative index (not coming from losses), two kinds of meta-atoms (electric and magnetic) are mixed to drive simultaneously the effective permittivity and permeability to negative values leading in turn to a negative index of refraction. In this paper, we show that two coupled structures with localized plasmons modes (e.g. cut-wires or split ring resonators) can exhibit negative refractive index by their own, by appropriately controlling the hybridization scheme of the plasmons modes. Because of small metal filling factor and reduced optical losses, the resulting structures may pave the way to realistic applications of metamaterials at optical frequencies.

  20. A Negative Index Metamaterial-Inspired UWB Antenna with an Integration of Complementary SRR and CLS Unit Cells for Microwave Imaging Sensor Applications

    PubMed Central

    Islam, Mohammad Tariqul; Islam, Md. Moinul; Samsuzzaman, Md.; Faruque, Mohammad Rashed Iqbal; Misran, Norbahiah

    2015-01-01

    This paper presents a negative index metamaterial incorporated UWB antenna with an integration of complementary SRR (split-ring resonator) and CLS (capacitive loaded strip) unit cells for microwave imaging sensor applications. This metamaterial UWB antenna sensor consists of four unit cells along one axis, where each unit cell incorporates a complementary SRR and CLS pair. This integration enables a design layout that allows both a negative value of permittivity and a negative value of permeability simultaneous, resulting in a durable negative index to enhance the antenna sensor performance for microwave imaging sensor applications. The proposed MTM antenna sensor was designed and fabricated on an FR4 substrate having a thickness of 1.6 mm and a dielectric constant of 4.6. The electrical dimensions of this antenna sensor are 0.20 ? × 0.29 ? at a lower frequency of 3.1 GHz. This antenna sensor achieves a 131.5% bandwidth (VSWR < 2) covering the frequency bands from 3.1 GHz to more than 15 GHz with a maximum gain of 6.57 dBi. High fidelity factor and gain, smooth surface-current distribution and nearly omni-directional radiation patterns with low cross-polarization confirm that the proposed negative index UWB antenna is a promising entrant in the field of microwave imaging sensors. PMID:26007721

  1. Microstructural design in cellular materials

    SciTech Connect

    Gibson, L.J.

    1992-01-31

    In last year's continuation proposal the work outlined for the period January 1991--January 1992 was focused on microstructural design of cellular materials; specifically we suggested honeycomb-like microstructures and composite foams with sandwich cell walls. We also planned to examine natural cellular materials to see if their structure suggests ways in which engineering cellular materials might be improved. We planned to make cellular materials with several different microstructures; to characterize their microstructure; and to measure their mechanical properties.

  2. ALSEP DESIGN SUMMARY Presentation Material

    E-print Network

    Rathbun, Julie A.

    ALSEP DESIGN SUMMARY Presentation Material BSR-2900 17 - 20 March 1970 NASA/MSC - Bendix Aerospace PASSIVE SEISMIC EXPERIMENT fR,... SUBPACKAGE NO. 2 "' ALSEP IN STOWED CONFIGURATION \\UIII'AI.¥Am ~~. I ~IN

  3. Negative Index of Refraction Observed in a Single Layer of ClosedRing Magnetic Dipole Resonators

    SciTech Connect

    Hao, Zhao; Martin, Michael C.; Harteneck, Bruce; Cabrini,Stefano; Anderson, Erik H.

    2007-11-27

    We report the results of a spectroscopic study of a singlelayer of metallic single closed ring resonators on free-standing thinmembrane at near-normal and grazing angles of incidence. When themagnetic component of the light is perpendicular to the ring plane, weobserve a negative index of refraction down to -1 around 150 terahertz(THz), attributed to a strong magnetic dipolar resonance and a broadelectric resonance in this metamaterial. We experimentally identify thedifferent resonance modes and the spectral region of negative refractiveindex on a series of samples with different feature and lattice sizes,comparing to electromagnetic simulations.

  4. Triangular lattice of carbon nanotube arrays for negative index of refraction and subwavelength lensing effect

    SciTech Connect

    Wang, Y.; Wang, X.; Rybczynski, J.; Wang, D.Z.; Kempa, K.; Ren, Z.F.

    2005-04-11

    Self-assembly of polystyrene microspheres has been utilized in a two-step masking technique to prepare triangular lattices of catalytic nanodots at low cost. Subsequent triangular lattices of aligned carbon nanotubes on a silicon substrate are achieved by plasma-enhanced chemical vapor deposition. Nickel is used both in the nanodots and in the secondary mask. The triangular lattices of carbon nanotube arrays as two-dimensional photonic crystals show higher geometrical symmetry than the hexagonal lattices previously reported, enabling broader applications including negative index of refraction and subwavelength lensing effect.

  5. Material feedback in digital design tools

    E-print Network

    Stanton, Christian J

    2009-01-01

    How do design tools feedback material behavior to the designer? Digital design tools in use by designers today provide a rich environment for design of form but offer little feedback of the material that ultimately realize ...

  6. Refraction of electromagnetic energy for wave packets incident on a negative-index medium is always negative

    E-print Network

    Sridhar, Srinivas

    Refraction of electromagnetic energy for wave packets incident on a negative-index medium is always February 2004 We analyze refraction of electromagnetic wave packets on passing from an isotropic positive to an isotropic negative-refractive-index medium. We definitively show that in all cases the energy is always

  7. www.srl.gatech.edu Material Design vs. Material Selection

    E-print Network

    Material Material Selection Material Database Alternatives Material Should the bread for the new sandwich be selected from the existing types of bread supplied by his baker, or should he design a new type of bread Example How can the deli owner choose between bread selection and bread design in the context

  8. Material and processes selection in conceptual design 

    E-print Network

    Krishnakumar, Karthikeyan

    2005-02-17

    Materials and manufacturing processes are an integral part of the design of a product. The need to combine materials and manufacturing processes selection during the early stages of the design has previously been realized. The work that generally...

  9. Shear-mediated contributions to the effective properties of soft acoustic metamaterials including negative index

    PubMed Central

    Forrester, Derek Michael; Pinfield, Valerie J.

    2015-01-01

    Here we show that, for sub-wavelength particles in a fluid, viscous losses due to shear waves and their influence on neighbouring particles significantly modify the effective acoustic properties, and thereby the conditions at which negative acoustic refraction occurs. Building upon earlier single particle scattering work, we adopt a multiple scattering approach to derive the effective properties (density, bulk modulus, wavenumber). We show,through theoretical prediction, the implications for the design of “soft” (ultrasonic) metamaterials based on locally-resonant sub-wavelength porous rubber particles, through selection of particle size and concentration, and demonstrate tunability of the negative speed zones by modifying the viscosity of the suspending medium. For these lossy materials with complex effective properties, we confirm the use of phase angles to define the backward propagation condition in preference to “single-” and “double-negative” designations. PMID:26686414

  10. Shear-mediated contributions to the effective properties of soft acoustic metamaterials including negative index.

    PubMed

    Forrester, Derek Michael; Pinfield, Valerie J

    2015-01-01

    Here we show that, for sub-wavelength particles in a fluid, viscous losses due to shear waves and their influence on neighbouring particles significantly modify the effective acoustic properties, and thereby the conditions at which negative acoustic refraction occurs. Building upon earlier single particle scattering work, we adopt a multiple scattering approach to derive the effective properties (density, bulk modulus, wavenumber). We show,through theoretical prediction, the implications for the design of "soft" (ultrasonic) metamaterials based on locally-resonant sub-wavelength porous rubber particles, through selection of particle size and concentration, and demonstrate tunability of the negative speed zones by modifying the viscosity of the suspending medium. For these lossy materials with complex effective properties, we confirm the use of phase angles to define the backward propagation condition in preference to "single-" and "double-negative" designations. PMID:26686414

  11. ALTERNATE MATERIALS IN DESIGN OF RADIOACTIVE MATERIAL PACKAGES

    SciTech Connect

    Blanton, P.; Eberl, K.

    2010-07-09

    This paper presents a summary of design and testing of material and composites for use in radioactive material packages. These materials provide thermal protection and provide structural integrity and energy absorption to the package during normal and hypothetical accident condition events as required by Title 10 Part 71 of the Code of Federal Regulations. Testing of packages comprising these materials is summarized.

  12. Materials by design: Merging proteins and music

    E-print Network

    Wong, Joyce Y.

    Tailored materials with tunable properties are crucial for applications as biomaterials, for drug delivery, as functional coatings, or as lightweight composites. An emerging paradigm in designing such materials is the ...

  13. MULTIFUNCTIONALTOPOLOGY DESIGN OF CELLULAR MATERIAL STRUCTURES1

    E-print Network

    Seepersad, Carolyn Conner

    1 MULTIFUNCTIONALTOPOLOGY DESIGN OF CELLULAR MATERIAL STRUCTURES1 Carolyn Conner Seepersad Engineering Georgia Institute of Technology, Atlanta, GA 30332 *and Georgia Tech Savannah, Savannah, GA 31407 Automation Conference. ABSTRACT Prismatic cellular or honeycomb materials exhibit favorable properties

  14. Managing Training Materials with Structured Text Design.

    ERIC Educational Resources Information Center

    Streit, Les D.; And Others

    1986-01-01

    Describes characteristics of structured text design; benefits of its use in training; benefits for developers of training materials and steps in preparing training materials. A case study illustrating how the structured text design process solved the sales training needs of the Mercedes-Benz Truck Company is presented. (MBR)

  15. DESIGN GUIDELINE 3.4 RECYCLING MATERIALS

    E-print Network

    Kamat, Vineet R.

    DESIGN GUIDELINE 3.4 RECYCLING MATERIALS Introduction This section addresses recycling and other. This document provides guidance for identifying materials which are recyclable or otherwise able to be diverted for separating and storing materials to be recycled and salvaged. Definitions Construction and Demolition Debris

  16. Design and Manufacture of Energy Absorbing Materials

    ScienceCinema

    Duoss, Eric

    2014-05-30

    Learn about an ordered cellular material that has been designed and manufactured using direct ink writing (DIW), a 3-D printing technology being developed at LLNL. The new material is a patterned cellular material that can absorb mechanical energy-a cushion-while also providing protection against sheering. This material is expected to find utility in application spaces that currently use unordered foams, such as sporting and consumer goods as well as defense and aerospace.

  17. Design and Manufacture of Energy Absorbing Materials

    SciTech Connect

    Duoss, Eric

    2014-05-28

    Learn about an ordered cellular material that has been designed and manufactured using direct ink writing (DIW), a 3-D printing technology being developed at LLNL. The new material is a patterned cellular material that can absorb mechanical energy-a cushion-while also providing protection against sheering. This material is expected to find utility in application spaces that currently use unordered foams, such as sporting and consumer goods as well as defense and aerospace.

  18. Microstructural design in cellular materials. Progress report

    SciTech Connect

    Gibson, L.J.

    1992-01-31

    In last year`s continuation proposal the work outlined for the period January 1991--January 1992 was focused on microstructural design of cellular materials; specifically we suggested honeycomb-like microstructures and composite foams with sandwich cell walls. We also planned to examine natural cellular materials to see if their structure suggests ways in which engineering cellular materials might be improved. We planned to make cellular materials with several different microstructures; to characterize their microstructure; and to measure their mechanical properties.

  19. METAMATERIALS: Large-area printed 3D negative-index metamaterial is flexible -Laser Focus World http://www.laserfocusworld.com/articles/print/volume-47/issue-8/world-news/metamaterials-large-area-printed-3d-negative-index-metamaterial-is-flexible.html[8/1

    E-print Network

    Rogers, John A.

    METAMATERIALS: Large-area printed 3D negative-index metamaterial is flexible - Laser Focus World-area printed 3D negative-index metamaterial is flexible METAMATERIALS: Large-area printed 3D negative, with the advent of a printing process that produces large-area 3D multilayer optical NIMs --8.7 × 8.7 cm square

  20. Material for Point Design (final summary of DIME material)

    SciTech Connect

    Bradley, Paul A.

    2014-02-25

    These slides summarize the motivation of the Defect Induced Mix Experiment (DIME) project, the “point design” of the Polar Direct Drive (PDD) version of the NIF separated reactant capsule, the experimental requirements, technical achievements, and some useful backup material. These slides are intended to provide much basic material in one convenient location and will hopefully be of some use for subsequent experimental projects.

  1. OLED microdisplay design and materials

    NASA Astrophysics Data System (ADS)

    Wacyk, Ihor; Prache, Olivier; Ali, Tariq; Khayrullin, Ilyas; Ghosh, Amalkumar

    2010-04-01

    AMOLED microdisplays from eMagin Corporation are finding growing acceptance within the military display market as a result of their excellent power efficiency, wide operating temperature range, small size and weight, good system flexibility, and ease of use. The latest designs have also demonstrated improved optical performance including better uniformity, contrast, MTF, and color gamut. eMagin's largest format display is currently the SXGA design, which includes features such as a 30-bit wide RGB digital interface, automatic luminance regulation from -45 to +70°C, variable gamma control, and a dynamic range exceeding 50:000 to 1. This paper will highlight the benefits of eMagin's latest microdisplay designs and review the roadmap for next generation devices. The ongoing development of reduced size pixels and larger format displays (up to WUXGA) as well as new OLED device architecture (e.g. high-brightness yellow) will be discussed. Approaches being explored for improved performance in next generation designs such as lowpower serial interfaces, high frame rate operation, and new operational modes for reduction of motion artifacts will also be described. These developments should continue to enhance the appeal of AMOLED microdisplays for a broad spectrum of near-to-the-eye applications such as night vision, simulation and training, situational awareness, augmented reality, medical imaging, and mobile video entertainment and gaming.

  2. 14 CFR 25.613 - Material strength properties and material design values.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Material strength properties and material design values. 25.613 Section 25.613...STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction General § 25.613 Material strength properties and material design values. (a) Material...

  3. Design, discovery and growth of novel materials

    SciTech Connect

    Canfield, Paul

    2012-06-07

    This editorial introduces the special issue on design, discovery, and growth of novel materials. The papers of this special issue review and reveal technical details of of how specific growths are developed and implemented.

  4. Microstructural design in cellular materials. Final report

    SciTech Connect

    Gibson, L.J.

    1995-12-01

    Cellular materials can be designed to have exceptional mechanical efficiency. In this project we have examined 2 cellular microstructures which give improved mechanical performance: honeycomb beams, with aligned holes parallel to the longitudinal axis of the beam and microsandwich foams, with cell walls designed to act as sandwich panels on a microstructural scale. We have also initiated work on interpenetrating composites using a cellular material as one phase.

  5. Multifunctional design of prismatic cellular materials

    NASA Astrophysics Data System (ADS)

    Seepersad, Carolyn C.; Kumar, Rajesh S.; Allen, Janet K.; Mistree, Farrokh; McDowell, David L.

    2004-01-01

    Low density, prismatic cellular materials have a combination of properties that make them suitable for multifunctional or multi-physics applications such as ultralight load-bearing combined with energy absorption and heat transfer. In this work, non-uniform, graded cellular materials are designed to achieve superior thermal and structural performance. A general multifunctional design approach is presented that integrates multiobjective decision-making with multi-physics analysis tools of structural and heat transfer performance. Approximate analysis models for heat transfer and elastic stiffness are utilized to analyze designs efficiently. Search/solution algorithms are used to solve multiobjective decisions by interfacing with customized and commercial software. During the design process, cell topology is assumed to be rectangular, but aspect ratios and dimensions of cells and cell walls are varied. Two design scenarios are considered maximum convective heat transfer and in-plane elastic stiffness in the first case and maximum convective heat transfer and elastic buckling strength in the second case. A portfolio of heat exchanger designs is generated with both periodic and functionally graded cells. Both single- and multi-objective performance are considered, and trade-offs are assessed between thermal and structural performance. Generalization of this approach is discussed for broader materials design applications in which material structures and processing paths are designed to achieve targeted properties and performance characteristics within a larger overall systems design process, and process-structure-property-performance relations are manifested on a hierarchy of length and time scales.

  6. Plasmon Injection to Compensate and Control Losses in Negative Index Metamaterials

    NASA Astrophysics Data System (ADS)

    Sadatgol, Mehdi; Ã-zdemir, ?ahin K.; Yang, Lan; Güney, Durdu Ã.-.

    2015-07-01

    Metamaterials have introduced a whole new world of unusual materials with functionalities that cannot be attained in naturally occurring material systems by mimicking and controlling the natural phenomena at subwavelength scales. However, the inherent absorption losses pose a fundamental challenge to the most fascinating applications of metamaterials. Based on a novel plasmon injection (PI or ? ) scheme, we propose a coherent optical amplification technique to compensate losses in metamaterials. Although the proof of concept device here operates under normal incidence only, our proposed scheme can be generalized to an arbitrary form of incident waves. The ? scheme is fundamentally different from major optical amplification schemes. It does not require a gain medium, interaction with phonons, or any nonlinear medium. The ? scheme allows for loss-free metamaterials. It is ideally suited for mitigating losses in metamaterials operating in the visible spectrum and is scalable to other optical frequencies. These findings open the possibility of reviving the early dreams of making "magical" metamaterials from scratch.

  7. Functionally graded materials: Design, processing and applications

    SciTech Connect

    Miyamoto, Y.; Kaysser, W.A.; Rabin, B.H.; Kawasaki, A.; Ford, R.G.

    1999-09-01

    In a Functionally Graded Material (FGM), the composition and structure gradually change over volume, resulting in corresponding changes in the properties of the material. By applying the many possibilities inherent in the FGM concept, it is anticipated that materials will be improved and new functions for them created. A comprehensive description of design, modeling, processing, and evaluation of FGMs as well as their applications is covered in this book. The contents include: lessons from nature; graded microstructures; modeling and design; characterization of properties; processing and fabrication; applications; and summary and outlook.

  8. Plasmon Injection to Compensate and Control Losses in Negative Index Metamaterials.

    PubMed

    Sadatgol, Mehdi; Özdemir, ?ahin K; Yang, Lan; Güney, Durdu Ö

    2015-07-17

    Metamaterials have introduced a whole new world of unusual materials with functionalities that cannot be attained in naturally occurring material systems by mimicking and controlling the natural phenomena at subwavelength scales. However, the inherent absorption losses pose a fundamental challenge to the most fascinating applications of metamaterials. Based on a novel plasmon injection (PI or ?) scheme, we propose a coherent optical amplification technique to compensate losses in metamaterials. Although the proof of concept device here operates under normal incidence only, our proposed scheme can be generalized to an arbitrary form of incident waves. The ? scheme is fundamentally different from major optical amplification schemes. It does not require a gain medium, interaction with phonons, or any nonlinear medium. The ? scheme allows for loss-free metamaterials. It is ideally suited for mitigating losses in metamaterials operating in the visible spectrum and is scalable to other optical frequencies. These findings open the possibility of reviving the early dreams of making "magical" metamaterials from scratch. PMID:26230802

  9. Mimicry of natural material designs and processes

    NASA Astrophysics Data System (ADS)

    Bond, G. M.; Richman, R. H.; McNaughton, W. P.

    1995-06-01

    Biological structural materials, although composed of unremarkable substances synthesized at low temperatures, often exhibit superior mechanical properties. In particular, the quality in which nearly all biologically derived materials excel is toughness. The advantageous mechanical properties are attributable to the hierarchical, composite, structural arrangements common to biological systems. Materials scientists and engineers have increasingly recognized that biological designs or processing approaches applied to man-made materials (biomimesis) may offer improvements in performance over conventional designs and fabrication methods. In this survey, the structures and processing routes of marine shells, avian eggshells, wood, bone, and insect cuticle are briefly reviewed, and biomimesis research inspired by these materials is discussed. In addition, this paper describes and summarizes the applications of biomineralization, self-assembly, and templating with proteins to the fabrication of thin ceramic films and nanostructure devices.

  10. Thermophotovoltaic emitter material selection and design

    SciTech Connect

    Saxton, P.C.; Moran, A.L.; Harper, M.J.; Lindler, K.W.

    1997-07-01

    Thermophotovoltaics (TPV) is a potentially attractive direct energy conversion technology. It reduces the need for complex machinery with moving parts and maintenance. TPV generators can be run from a variety of heat sources including waste heat for smaller scale operations. The US Naval Academy`s goal was to build a small experimental thermophotovoltaic generator powered by combustion gases from a General Electric T-58 helicopter gas turbine. The design of the generator imposes material limitations that directly affect emitter and structural materials selection. This paper details emitter material goals and requirements, and the methods used to select suitable candidate emitter materials for further testing.

  11. Simulation-assisted materials design for the concurrent design of materials and products

    NASA Astrophysics Data System (ADS)

    McDowell, David L.

    2007-09-01

    Engineering design has historically been taught using the paradigm of selecting materials on the basis of tabulated databases of properties (mechanical, physical, chemical, etc.). Recent trends have moved toward concurrent design of material composition and microstructure together with the component/system level. The goal is to tailor materials to meet specifi ed ranges of performance requirements of the overall system. Often these multiple performance requirements are in confl ict in terms of their demands on composition and microstructure. This paper explores the elements of a decision-based robust design framework for concurrent design of materials and products, focusing on enhancing the fraction of decisions supported by modeling and simulation.

  12. Photonic band structure and effective medium properties of doubly-resonant core-shell metallo-dielectric nanowire arrays: low-loss, isotropic optical negative-index behavior

    NASA Astrophysics Data System (ADS)

    Abujetas, D. R.; Paniagua-Domínguez, R.; Nieto-Vesperinas, M.; Sánchez-Gil, J. A.

    2015-12-01

    We investigate theoretically and numerically the photonic band structure in the optical domain of an array of core–shell metal-semiconductor nanowires. Corresponding negative-index photonic bands are calculated, showing isotropic equifrequency surfaces. The effective (negative) electric permittivity and magnetic permeability, retrieved from S-parameters, are used to compare the performance of such nanowire arrays with homogeneous media in canonical examples, such as refraction through a prism and flat-lens focusing. Very good agreement is found, confirming the effective medium behavior of the nanowire array as a low-loss, isotropic (2D) and bulk, optical negative index metamaterial. Indeed, disorder is introduced to further stress its robustness.

  13. Photonic band structure and effective medium properties of doubly-resonant core-shell metallo-dielectric nanowire arrays: low-loss, isotropic optical negative-index behavior

    E-print Network

    Abujetas, D R; Nieto-Vesperinas, M; Sánchez-Gil, J A

    2015-01-01

    We investigate theoretically and numerically the photonic band structure in the optical domain of an array of core-shell metal-semiconductor nanowires. Corresponding negative-index photonic bands are calculated, showing isotropic equifrequency surfaces. The effective (negative) electric permittivity and magnetic permeability, retrieved from S parameters, are used to compare the performance of such nanowire arrays with homogeneous media in canonical examples, such as refraction through a prism and flat-lens focusing. Very good agreement is found, indeed confirming the effective medium behavior of the nanowire array as a low-loss, isotropic (2D) and bulk, optical negative index metamaterial. Indeed, disorder is introduced to further stress its robustness

  14. An Ontology Design Pattern for Material Transformation

    E-print Network

    Hitzler, Pascal

    of energy, and thus carbon and other greenhouse gases, which are then"embodied" in the consumption process the Seman- tic Trajectory pattern (STODP) [3]. The remaining contribution to the total embodied energyAn Ontology Design Pattern for Material Transformation Charles Vardeman1 , Adila A. Krisnadhi2

  15. ITER status, design and material objectives

    NASA Astrophysics Data System (ADS)

    Aymar, R.; International Team

    2002-12-01

    During the ITER Engineering Design Activities (EDA), completed in July 2001, the Joint Central Team and Home Teams developed a robust design of ITER, summarised in this paper, with parameters which fully meet the required scientific and technological objectives, construction costs and safety requirements, with appropriate margins. The design is backed by R&D to qualify the technology, including materials R&D. Materials for ITER components have been selected largely because of their availability and well-established manufacturing technologies, taking account of the low fluence experienced during neutron irradiation, and the experimental nature of the device. Nevertheless, for specific needs relevant to a future fusion reactor, improved materials, in particular for magnet structures, in-vessel components, and joints between the different materials needed for plasma facing components, have been successfully developed. Now, with the technical readiness to decide on ITER construction, negotiations, supported by coordinated technical activities of an international team and teams from participant countries, are underway on joint construction of ITER with a view to the signature/ratification of an agreement in 2003.

  16. Numerical simulations of negative-index refraction in wedge-shaped metamaterials Z. G. Dong, S. N. Zhu,* and H. Liu

    E-print Network

    Cao, Wenwu

    Numerical simulations of negative-index refraction in wedge-shaped metamaterials Z. G. Dong, S. N to evalu- ate its refraction behavior. Four frequency bands, namely, the stop band, left-handed band, ultralow-index band, and positive-index band, are distinguished according to the refracted field

  17. Progress in material design for biomedical applications

    PubMed Central

    Tibbitt, Mark W.; Rodell, Christopher B.; Burdick, Jason A.; Anseth, Kristi S.

    2015-01-01

    Biomaterials that interface with biological systems are used to deliver drugs safely and efficiently; to prevent, detect, and treat disease; to assist the body as it heals; and to engineer functional tissues outside of the body for organ replacement. The field has evolved beyond selecting materials that were originally designed for other applications with a primary focus on properties that enabled restoration of function and mitigation of acute pathology. Biomaterials are now designed rationally with controlled structure and dynamic functionality to integrate with biological complexity and perform tailored, high-level functions in the body. The transition has been from permissive to promoting biomaterials that are no longer bioinert but bioactive. This perspective surveys recent developments in the field of polymeric and soft biomaterials with a specific emphasis on advances in nano- to macroscale control, static to dynamic functionality, and biocomplex materials. PMID:26598696

  18. Computational Materials Program for Alloy Design

    NASA Technical Reports Server (NTRS)

    Bozzolo, Guillermo

    2005-01-01

    The research program sponsored by this grant, "Computational Materials Program for Alloy Design", covers a period of time of enormous change in the emerging field of computational materials science. The computational materials program started with the development of the BFS method for alloys, a quantum approximate method for atomistic analysis of alloys specifically tailored to effectively deal with the current challenges in the area of atomistic modeling and to support modern experimental programs. During the grant period, the program benefited from steady growth which, as detailed below, far exceeds its original set of goals and objectives. Not surprisingly, by the end of this grant, the methodology and the computational materials program became an established force in the materials communitiy, with substantial impact in several areas. Major achievements during the duration of the grant include the completion of a Level 1 Milestone for the HITEMP program at NASA Glenn, consisting of the planning, development and organization of an international conference held at the Ohio Aerospace Institute in August of 2002, finalizing a period of rapid insertion of the methodology in the research community worlwide. The conference, attended by citizens of 17 countries representing various fields of the research community, resulted in a special issue of the leading journal in the area of applied surface science. Another element of the Level 1 Milestone was the presentation of the first version of the Alloy Design Workbench software package, currently known as "adwTools". This software package constitutes the first PC-based piece of software for atomistic simulations for both solid alloys and surfaces in the market.Dissemination of results and insertion in the materials community worldwide was a primary focus during this period. As a result, the P.I. was responsible for presenting 37 contributed talks, 19 invited talks, and publishing 71 articles in peer-reviewed journals, as detailed later in this Report.

  19. Quantum Design of Complex Nanostructured Electronic Materials

    NASA Astrophysics Data System (ADS)

    Williamson, Andrew

    2007-03-01

    Over the last decade, our ability to predict the fundamental properties of nanoscale building blocks such as quantum dots, wires, and slabs has improved dramatically. In particular, first principles modeling techniques can now routinely predict how the structural, electronic, optical, and transport properties of these building blocks depends on their size, shape, composition, and surface structure. In this talk we present the results of three projects designed to build upon these fundamental studies to engineer novel, nanostructured materials with tailored electronic properties. These complex, nanoscale heterostructure materials utilize both the unique properties of their nanoscale building blocks and the interactions between the constituent building blocks to engineer the ideal material properties. (i) We will describe the design of a silicon/germanium nanowire based thermoelectric material whose performance is enhanced by suppressing thermal transport and enhancing electronic transport. This is achieved by engineering the nanoscale confinement and scattering of phonons and electrons. (ii) We will describe the design of a silicon based laser, constructed from silicon nanocrystals embedded in an amorphous silicon nitride matrix. Models of the electronic states in the nanocrystal, the surrounding matrix, and the interface between the two, enable us to optimize the optical efficiency of the emission and electrically pump the laser. (iii) We will describe the use of first principles models to predict the optical response of silicon nanowires. These predictions are used to interpret the results of optical scatterometry metrology which can measure the size and surface roughness of nanoscale electronic devices produced by a combination of lithography and etching. This work was performed under the auspices of the U.S. Dept. of Energy at the University of California/Lawrence Livermore National Laboratory under contract no. W-7405-Eng-48.

  20. Use of advanced composite materials for innovative building design solutions/

    E-print Network

    Lau, Tak-bun, Denvid

    2009-01-01

    Advanced composite materials become popular in construction industry for the innovative building design solutions including strengthening and retrofitting of existing structures. The interface between different materials ...

  1. Optimized energy harvesting materials and generator design

    NASA Astrophysics Data System (ADS)

    Graf, Christian; Hitzbleck, Julia; Feller, Torsten; Clauberg, Karin; Wagner, Joachim; Krause, Jens; Maas, Jürgen

    2013-04-01

    Electroactive polymers are soft capacitors made of thin elastic and electrically insulating films coated with compliant electrodes offering a large amount of deformation. They can either be used as actuators by applying an electric charge or they can be used as energy converters based on the electrostatic principle. These unique properties enable the industrial development of highly efficient and environmentally sustainable energy converters, which opens up the possibility to further exploit large renewable and inexhaustible energy sources like wind and water that are widely unused otherwise. Compared to other electroactive polymer materials, polyurethanes, whose formulations have been systematically modified and optimized for energy harvesting applications, have certain advantages over silicones and acrylates. The inherently higher dipole content results in a significantly increased permittivity and the dielectric breakdown strength is higher, too, whereby the overall specific energy, a measure for the energy gain, is better by at least factor ten, i.e. more than ten times the energy can be gained out of the same amount of material. In order to reduce conduction losses on the electrode during charging and discharging, a highly conductive bidirectional stretchable electrode has been developed. Other important material parameters like stiffness and bulk resistivity have been optimized to fit the requirements. To realize high power energy harvesting systems, substantial amounts of electroactive polymer material are necessary as well as a smart mechanical and electrical design of the generator. In here we report on different measures to evaluate and improve electroactive polymer materials for energy harvesting by e.g. reducing the defect occurrence and improving the electrode behavior.

  2. Materials design principles of ancient fish armour

    NASA Astrophysics Data System (ADS)

    Bruet, Benjamin J. F.; Song, Juha; Boyce, Mary C.; Ortiz, Christine

    2008-09-01

    Knowledge of the structure-property-function relationships of dermal scales of armoured fish could enable pathways to improved bioinspired human body armour, and may provide clues to the evolutionary origins of mineralized tissues. Here, we present a multiscale experimental and computational approach that reveals the materials design principles present within individual ganoid scales from the `living fossil' Polypterus senegalus. This fish belongs to the ancient family Polypteridae, which first appeared 96 million years ago during the Cretaceous period and still retains many of their characteristics. The mechanistic origins of penetration resistance (approximating a biting attack) were investigated and found to include the juxtaposition of multiple distinct reinforcing composite layers that each undergo their own unique deformation mechanisms, a unique spatial functional form of mechanical properties with regions of differing levels of gradation within and between material layers, and layers with an undetectable gradation, load-dependent effective material properties, circumferential surface cracking, orthogonal microcracking in laminated sublayers and geometrically corrugated junctions between layers.

  3. Designer protein-based performance materials.

    PubMed

    Kumar, Manoj; Sanford, Karl J; Cuevas, William A; Cuevas, William P; Du, Mai; Collier, Katharine D; Chow, Nicole

    2006-09-01

    Repeat sequence protein polymer (RSPP) technology provides a platform to design and make protein-based performance polymers and represents the best nature has to offer. We report here that the RSPP platform is a novel approach to produce functional protein polymers that have both biomechanical and biofunctional blocks built into one molecule by design, using peptide motifs. We have shown that protein-based designer biopolymers can be made using recombinant DNA technology and fermentation and offer the ability to screen for desired properties utilizing the tremendous potential diversity of amino acid combinations. The technology also allows for large-scale manufacturing with a favorable fermentative cost-structure to deliver commercially viable performance polymers. Using three diverse examples with antimicrobial, textile targeting, and UV-protective agent, we have introduced functional attributes into structural protein polymers and shown, for example, that the functionalized RSPPs have possible applications in biodefense, industrial biotechnology, and personal care areas. This new class of biobased materials will simulate natural biomaterials that can be modified for desired function and have many advantages over conventional petroleum-based polymers. PMID:16961316

  4. Design concepts for pressurized lunar shelters utilizing indigenous materials

    NASA Technical Reports Server (NTRS)

    Happel, John Amin; Willam, Kaspar; Shing, Benson

    1991-01-01

    The objective is to design a pressurized shelter build of indigenous lunar material. The topics are presented in viewgraph form and include the following: lunar conditions which impact design; secondary factors; review of previously proposed concepts; cross section of assembly facility; rationale for indigenous materials; indigenous material choices; cast basalt properties; design variables; design 1, cylindrical segments; construction sequence; design 2, arch-slabs with post-tensioned ring girders; and future research.

  5. Tools for Material Design and Selection

    NASA Astrophysics Data System (ADS)

    Wehage, Kristopher

    The present thesis focuses on applications of numerical methods to create tools for material characterization, design and selection. The tools generated in this work incorporate a variety of programming concepts, from digital image analysis, geometry, optimization, and parallel programming to data-mining, databases and web design. The first portion of the thesis focuses on methods for characterizing clustering in bimodal 5083 Aluminum alloys created by cryomilling and powder metallurgy. The bimodal samples analyzed in the present work contain a mixture of a coarse grain phase, with a grain size on the order of several microns, and an ultra-fine grain phase, with a grain size on the order of 200 nm. The mixing of the two phases is not homogeneous and clustering is observed. To investigate clustering in these bimodal materials, various microstructures were created experimentally by conventional cryomilling, Hot Isostatic Pressing (HIP), Extrusion, Dual-Mode Dynamic Forging (DMDF) and a new 'Gradient' cryomilling process. Two techniques for quantitative clustering analysis are presented, formulated and implemented. The first technique, the Area Disorder function, provides a metric of the quality of coarse grain dispersion in an ultra-fine grain matrix and the second technique, the Two-Point Correlation function, provides a metric of long and short range spatial arrangements of the two phases, as well as an indication of the mean feature size in any direction. The two techniques are implemented on digital images created by Scanning Electron Microscopy (SEM) and Electron Backscatter Detection (EBSD) of the microstructures. To investigate structure--property relationships through modeling and simulation, strategies for generating synthetic microstructures are discussed and a computer program that generates randomized microstructures with desired configurations of clustering described by the Area Disorder Function is formulated and presented. In the computer program, two-dimensional microstructures are generated by Random Sequential Adsorption (RSA) of voxelized ellipses representing the coarse grain phase. A simulated annealing algorithm is used to geometrically optimize the placement of the ellipses in the model to achieve varying user-defined configurations of spatial arrangement of the coarse grains. During the simulated annealing process, the ellipses are allowed to overlap up to a specified threshold, allowing triple junctions to form in the model. Once the simulated annealing process is complete, the remaining space is populated by smaller ellipses representing the ultra-fine grain phase. Uniform random orientations are assigned to the grains. The program generates text files that can be imported in to Crystal Plasticity Finite Element Analysis Software for stress analysis. Finally, numerical methods and programming are applied to current issues in green engineering and hazard assessment. To understand hazards associated with materials and select safer alternatives, engineers and designers need access to up-to-date hazard information. However, hazard information comes from many disparate sources and aggregating, interpreting and taking action on the wealth of data is not trivial. In light of these challenges, a Framework for Automated Hazard Assessment based on the GreenScreen list translator is presented. The framework consists of a computer program that automatically extracts data from the GHS-Japan hazard database, loads the data into a machine-readable JSON format, transforms the JSON document in to a GreenScreen JSON document using the GreenScreen List Translator v1.2 and performs GreenScreen Benchmark scoring on the material. The GreenScreen JSON documents are then uploaded to a document storage system to allow human operators to search for, modify or add additional hazard information via a web interface.

  6. Materials Design for Block Copolymer Lithography

    NASA Astrophysics Data System (ADS)

    Sweat, Daniel Patrick

    Block copolymers (BCPs) have attracted a great deal of scientific and technological interest due to their ability to spontaneously self-assemble into dense periodic nanostructures with a typical length scale of 5 to 50 nm. The use of self-assembled BCP thin-films as templates to form nanopatterns over large-area is referred to as BCP lithography. Directed self-assembly of BCPs is now viewed as a viable candidate for sub-20 nm lithography by the semiconductor industry. However, there are multiple aspects of assembly and materials design that need to be addressed in order for BCP lithography to be successful. These include substrate modification with polymer brushes or mats, tailoring of the block copolymer chemistry, understanding thin-film assembly and developing epitaxial like methods to control long range alignment. The rational design, synthesis and self-assembly of block copolymers with large interaction parameters (chi) is described in the first part of this dissertation. Two main blocks were chosen for introducing polarity into the BCP system, namely poly(4-hydroxystyrene) and poly(2-vinylpyridine). Each of these blocks are capable of ligating Lewis acids which can increase the etch contrast between the blocks allowing for facile pattern transfer to the underlying substrate. These BCPs were synthesized by living anionic polymerization and showed excellent control over molecular weight and dispersity, providing access to sub 5-nm domain sizes. Polymer brushes consist of a polymer chain with one end tethered to the surface and have wide applicability in tuning surface energy, forming responsive surfaces and increasing biocompatibility. In the second part of the dissertation, we present a universal method to grow dense polymer brushes on a wide range of substrates and combine this chemistry with BCP assembly to fabricate nanopatterned polymer brushes. This is the first demonstration of introducing additional functionality into a BCP directing layer and opens up a wide slew of applications from directed self-assembly to biomaterial engineering.

  7. Distance Education: The Design of Study Materials. 2nd Edition.

    ERIC Educational Resources Information Center

    Meacham, E. D.; Evans, D. E.

    Based on both practical experience and theoretical studies, this manual provides the foundation for the design of effective distance education teaching materials. An overview presents an outline model of major design considerations for correspondence materials that provides a context for design decisions, with categories chosen to assist in the…

  8. 15 CFR 922.22 - Development of designation materials.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 3 2014-01-01 2014-01-01 false Development of designation materials. 922.22 Section 922.22 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade... Sanctuaries § 922.22 Development of designation materials. (a) In designating a National Marine Sanctuary,...

  9. 15 CFR 922.22 - Development of designation materials.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 3 2013-01-01 2013-01-01 false Development of designation materials. 922.22 Section 922.22 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade... Sanctuaries § 922.22 Development of designation materials. (a) In designating a National Marine Sanctuary,...

  10. FOREWORD: Computational methodologies for designing materials Computational methodologies for designing materials

    NASA Astrophysics Data System (ADS)

    Rahman, Talat S.

    2009-02-01

    It would be fair to say that in the past few decades, theory and computer modeling have played a major role in elucidating the microscopic factors that dictate the properties of functional novel materials. Together with advances in experimental techniques, theoretical methods are becoming increasingly capable of predicting properties of materials at different length scales, thereby bringing in sight the long-sought goal of designing material properties according to need. Advances in computer technology and their availability at a reasonable cost around the world have made tit all the more urgent to disseminate what is now known about these modern computational techniques. In this special issue on computational methodologies for materials by design we have tried to solicit articles from authors whose works collectively represent the microcosm of developments in the area. This turned out to be a difficult task for a variety of reasons, not the least of which is space limitation in this special issue. Nevertheless, we gathered twenty articles that represent some of the important directions in which theory and modeling are proceeding in the general effort to capture the ability to produce materials by design. The majority of papers presented here focus on technique developments that are expected to uncover further the fundamental processes responsible for material properties, and for their growth modes and morphological evolutions. As for material properties, some of the articles here address the challenges that continue to emerge from attempts at accurate descriptions of magnetic properties, of electronically excited states, and of sparse matter, all of which demand new looks at density functional theory (DFT). I should hasten to add that much of the success in accurate computational modeling of materials emanates from the remarkable predictive power of DFT, without which we would not be able to place the subject on firm theoretical grounds. As we know and will also see from the collection of works here, DFT also provides a platform for testing, improving, and evaluating the feasibility of more approximate methods whose need has become even more urgent. This is understandable since functional materials, given their limited translational symmetry, necessitate the usage of unit cells with a large number of atoms (sometimes in hundreds). Even if DFT codes were efficient enough to handle several hundred atoms in the calculational super-cell, the extraction of equilibrium geometry for such systems requires injection of more efficient methodology, as geometry is the input and not the output of a DFT calculation. Equally important is the need to calculate the temperature dependencies of material properties and for simulations to be carried out at length scales suitable for incorporating kinetic effects from competing processes and cooperative effects from constituting entities. It is true that codes based on DFT are becoming increasingly efficient and that methods such as ab initio molecular dynamics simulations are available for simulations of systems at temperatures above 0 K. However, such approaches still have a way to go before they can be readily applied to materials with complex geometries and composition, and for time and length scales that are relevant to realistic environments in the laboratory. Several articles here represent some of the recent advances towards 'multi-scale' modeling of materials. Among the articles that focus exclusively on DFT, the contribution by Weinert et al [1] summarizes some of the advances made to better describe magnetic properties and entropic effects. The article by Kyrychenko and Ullrich [2] discusses recent developments in time dependent DFT to describe transport properties and absorption spectra of solids. Their model allows for a comprehensive treatment of electron--electron interaction, screening and correlation effects which are necessary for proper description of properties of the excited state. The contribution by Langreth and co-workers [3] summarizes their recent efforts at incorpo

  11. Piezoactuator Design Considering the Optimum Placement of FGM Piezoelectric Material

    E-print Network

    Paulino, Glaucio H.

    Piezoactuator Design Considering the Optimum Placement of FGM Piezoelectric Material Ronny C of material properties and are characterized by spatially varying microstructures. Recently, the FGM concept of a piezoceramic FGM. Thus, the gradation of piezoceramic properties can influence the performance

  12. Biosynthetic Polypeptides as Templates in Materials Design

    NASA Astrophysics Data System (ADS)

    Kiick, Kristi

    2007-03-01

    Biosynthetic routes to protein-based polymeric materials offer important opportunities for the production of well-defined macromolecular templates, owing to the control of sequence and molecular weight inherent in the biosynthesis of proteins. In particular, the biosynthesis of polypeptides with controlled presentation of functional groups in multiple positions, coupled with their subsequent chemical modification with biologically relevant ligands, will permit the production of well-defined, bioactive macromolecules that may provide insight into biological binding events in which multivalent binding is important. Modification of the well-defined macromolecules with ligands such as saccharides has application in the study of events such as toxin neutralization and mediation of the immune and inflammatory responses. In this work, alanine-rich polypeptides of both random coil and helical conformations, equipped with glutamic acid residues to impart chemical versatility, have been produced via biosynthetic strategies. Analysis via spectroscopic and calorimetric methods indicates that the polypeptides adopt helical, beta-sheet, or random-coil conformations that can be controlled with variations in temperature, pH, and salt concentration; the conformational behavior of the polypeptides is not compromised upon chemical modification with saccharides. The binding of these macromolecules to bacterial toxins has been characterized via immunochemical and spectroscopic methods; results indicate that specific architectural features of the glycopolymer scaffold cause changes in the binding of these molecules to multivalent receptors. Given the chemical flexibility in the design of such scaffolds, they can be modified with many different moieties in addition to saccharides, so multiple opportunities exist for their application in areas where control of active side chains is important, such as in biomaterials, electronic devices, and bioinorganic structures.

  13. Nanoscale material design for photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Bao, Hua

    Solar cell technology directly converts the clean, abundant energy of the sun into electricity. To build solar cell modules with low cost and high energy conversion efficiency, nanomaterials such as nanowires, nanotubes and quantum dots are very promising candidates, due to their novel thermal, electrical, and optical properties. This research seeks to use silicon nanowire, carbon nanotube, and semiconductor quantum dot to achieve high optical absorption and low electron-phonon coupling. Multiscale simulation and experiments are combined to investigate the thermal radiative properties of nanowire/nanotube array structures and the electron-phonon interaction in semiconductor quantum dots. Optical properties of nanowire/nanotube structures are numerically investigated by combined ab initio calculation and computational electromagnetic calculations. At the atomic scale, ab initio calculations based on density functional theory are performed to evaluate the spectral dielectric function of the material using the initial atomic structure as the only input parameter. This method considers different absorption mechanisms from far infrared to visible spectrum, and its effectiveness is demonstrated using the material GaAs and small carbon nanotubes. At the nanoscale, the predicted dielectric function of nanowire/nanotube is used as an input parameter in finite-difference time-domain method, so that the optical properties of devices such as nanowire/nanotube arrays can be obtained. Based on this scheme, we have shown that the vertically aligned multiwalled carbon nanotube arrays are nearly perfect absorber in the visible spectrum. Silicon nanowire arrays are less absorptive than carbon nanotube, but we propose and demonstrate that their optical absorption can be greatly enhanced by introducing structural randomness, including random positioning, diameter and length. The enhanced optical absorption implies potential enhancement of the overall efficiency of nanotube/nanowire array solar cells. Phonon-assisted electron decay in semiconductor quantum dots is also investigated in this work. In semiconductor solar cell, a large portion of energy loss is by the fast hot electron cooling, in which a high energy electron decays to the electronic band gap by creating a series of phonons. The excessive electrical energy is then converted to heat and wasted, so that the total photovoltaic energy conversion efficiency is limited. The electron decay rate reduces in semiconductor quantum dots, due to the discrete electron energy levels created by quantum confinement. To design quantum dots with the slowest decay rate, we use the non-adiabatic molecular dynamics to perform real-time simulations of the phonon-assisted electron decay process. This method is based on time-dependent density functional theory, and can directly predict the phonon-assisted electron decay time using the initial quantum dot structure as the only input. The numerical simulation shows that the phonon-induced electron decay can be slowed down in a small PbSe quantum dot. The temperature-dependent relaxation in this quantum dot is also studied, which helps us to propose a multi-channel relaxation mechanism. This mechanism provides new insights to the understanding of electron decay process in quantum dots. The results from this study have potentially important applications in solar energy harvesting and radiative thermal management. It offers a new perspective of nanoscale engineering of materials to achieve more efficient photovoltaic energy conversion.

  14. Diamond detector - material science, design and application

    NASA Astrophysics Data System (ADS)

    Gaowei, Mengjia

    Modern synchrotrons, such as the NSLS-II, will enable unprecedented science by having extremely high brightness and flux with exceptional beam stability. These capabilities create a harsh and demanding environment for measuring the characteristics of the x-ray beam. In many cases, existing measurement techniques fail completely, requiring the development of new detectors which can meet the demands of the synchrotron. The combination of diamond properties ranked diamond an appealing candidate in the field of radiation detection in extreme conditions and it has been used as x-ray sensor material for decades. However, only until the development of chemical vapor deposition (CVD) process in the synthesis of diamond that has it been considered for wider applications in the state-of-art synchrotron light sources as part of beamline diagnostics, including the detection of x-ray beam flux and position. While defects and dislocations in CVD grown single crystal diamonds are inevitable, there are solutions in other aspects of a device fabrication to compensate this technological downside, including improving device performance in engineering diamond surface electrode materials and patterns and slicing and polishing diamond plates into thinner pieces. The content of this dissertation summarizes our effort in addressing several problems we encounter in the process of design and fabrication of single crystal CVD diamond based electronic devices. In order to study the generation of post-anneal photoconductive gain in our devices we have discussed in section 3 and 4 the two criteria for the observation of photoconductive current. In section 3 we reveal the correlation between structural defects in diamond and the post-anneal photoconductive regions. Section 4 introduces the measurements of hard x-ray photoelectron spectroscopy (HAXPES) we applied to investigate the diamond-metal Schottky barrier height for several metals and diamond surface terminations. The position of the diamond valence-band maximum was determined by theoretically calculating the diamond density of states and applying cross section corrections. The diamond-platinum Schottky barrier height was lowered by 0.2 eV after thermal annealing, indicating annealing may increase carrier injection in diamond devices leading to photoconductive gain. In order to adapt our device to soft x-ray applications, efforts are made to develop a thin diamond position monitor for lowering device absorption. In section 5 we have discussed the fabrication and testing of thin diamond x-ray monitors made from diamond plates with nominal thickness of 30microm, which is 1/10th of the thickness of the diamonds we previously used. Calibration results of this detector are presented and discussed in comparison with thicker diamond sensors. Section 6 introduces our effort on the investigation of carrier loss mechanism in diamond detectors. Near edge responsivity in diamond x-ray detectors has been used to confirm the carrier loss mechanism as recombination due to diffusion into the incident electrode. We present a detailed study of the bias dependence of the diamond responsivity across the carbon k-edge. The carrier loss is modeled by incorporating a characteristic recombination length into the absorption model and is shown to agree well with Monte Carlo simulated carrier losses. In addition, nitrogen doped ultrananocrystalline diamond (nUNCD) grown on the surface of a CVD single crystal diamond as an alternative contact to metal is tested in the similar measurements as the metal contact diamond. nUNCD has a much lower x-ray absorption than metal contacts and is designed to improve the performance of our device. This diamond is calibrated over a wide photon energy range from 0.2 keV to 28 keV, and compared with platinum coated diamond. Results of these studies will be presented and discussed in section 7. Future work has been proposed in the last section in improving the design and fabrication of diamond based electronics as well as in the investigation to enhance our understanding of its material and

  15. 46 CFR 58.05-1 - Material, design and construction.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Main Propulsion Machinery § 58.05-1 Material, design and construction...design, construction, workmanship, and arrangement of main propulsion machinery and of each auxiliary, directly...

  16. 46 CFR 58.05-1 - Material, design and construction.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Main Propulsion Machinery § 58.05-1 Material, design and construction...design, construction, workmanship, and arrangement of main propulsion machinery and of each auxiliary, directly...

  17. "Safety Concrete" A Material Designed to Fail

    E-print Network

    , Mississippi #12;Motivation to Engineer a Novel Cement-Based Material In the event of a terrorist bombing science approach to engineer a cement- based material with unique properties Analogous to safety glass Terminate hydration reaction and induce drying shrinkage #12;Summary & Future Work Impact and Shock Tube

  18. Design and Application of Materials in Science

    E-print Network

    New South Wales, University of

    Building (F8) Room G23 Lecturer 27 July 1 NO CLASSES 3 Aug 2 Introduction Atomic bonding JH Packing of atoms in solids JH 10 Aug 3 Elastic deformation of materials JH Plastic deformation of materials JH 17 Aug 4 Dislocations Strengthening mechanisms JH Fast fracture Ethics in Engineering JH 24 Aug 5 Fatigue

  19. Computer-Aided Design Of Sheet-Material Parts

    NASA Technical Reports Server (NTRS)

    Gilbert, Jeffrey L.; Paternoster, Vincent Y.; Levitt, Maureen L.; Osterloh, Mark R.

    1991-01-01

    Computer-aided-design system partly automates tedious process of designing and guiding assembly of small pieces of flat sheet material into large surfaces that approximate smoothly curved surfaces having complicated three-dimensional shapes. Capability provides for flexibility enabling designer to assess quickly and easily effects of changes in design in making engineering compromises among various sizes and shapes. Saves time and money in both design and fabrication. Used in rocket-engine application and other applications requiring design of sheet-material parts.

  20. Synthesis and design of silicide intermetallic materials

    SciTech Connect

    Petrovic, J.J.; Castro, R.G.; Butt, D.P.; Park, Y.; Hollis, K.J.; Kung, H.H.

    1998-11-01

    The overall objective of this program is to develop structural silicide-based materials with optimum combinations of elevated temperature strength/creep resistance, low temperature fracture toughness, and high temperature oxidation and corrosion resistance for applications of importance to the U.S. processing industry. A further objective is to develop silicide-based prototype industrial components. The ultimate aim of the program is to work with industry to transfer the structural silicide materials technology to the private sector in order to promote international competitiveness in the area of advanced high temperature materials and important applications in major energy-intensive U.S. processing industries.

  1. 46 CFR 58.05-1 - Material, design and construction.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... equivalent to the standards established by the ABS Steel Vessel Rules (incorporated by reference, see 46 CFR... 46 Shipping 2 2012-10-01 2012-10-01 false Material, design and construction. 58.05-1 Section 58.05... AUXILIARY MACHINERY AND RELATED SYSTEMS Main Propulsion Machinery § 58.05-1 Material, design...

  2. 30 CFR 18.92 - Quality of material and design.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Quality of material and design. 18.92 Section 18.92 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... Approval of Electrically Operated Mining Equipment § 18.92 Quality of material and design. (a)...

  3. 30 CFR 18.92 - Quality of material and design.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Quality of material and design. 18.92 Section 18.92 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... Approval of Electrically Operated Mining Equipment § 18.92 Quality of material and design. (a)...

  4. 30 CFR 18.92 - Quality of material and design.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Quality of material and design. 18.92 Section 18.92 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... Approval of Electrically Operated Mining Equipment § 18.92 Quality of material and design. (a)...

  5. The Design of Computer Multimedia Material for English Language Learning

    E-print Network

    The Design of Computer Multimedia Material for English Language Learning Yu liang Ting Oriental-designed digital learning material. As the development of IT, many areas of English learning have employed computers as learning tools. In the area of English writing, the most common use of the computer technology

  6. Material Genome Prediction Based Analyses and Design for Polymer Nanocomposites

    E-print Network

    Chen, Wei

    Material Genome Prediction Based Analyses and Design for Polymer Nanocomposites Students: He and design new optimal polymer nanocomposites. This objective matches well with the aim of the Material%. Tallying with the MGI requirement of data transparency, our new data resource for polymer nanocomposites

  7. Design for containment of hazardous materials

    SciTech Connect

    Murray, R.C. ); McDonald, J.R. )

    1991-03-01

    Department of Energy, (DOE), facilities across the United States, use wind and tornado design and evaluation criteria based on probabilistic performance goals. In addition, other programs such as Advanced Light Water Reactors, New Production Reactors, and Individual Plant Examinations for External Events for commercial nuclear power plants utilize design and evaluation criteria based on probabilistic performance goals. The use of probabilistic performance goals is a departure from design practice for commercial nuclear power plants which have traditionally been designed utilizing a conservative specification of wind and tornado loading combined with deterministic response evaluation methods and permissible behavior limits. Approaches which utilize probabilistic wind and tornado hazard curves for specification of loading and deterministic response evaluation methods and permissible behavior limits are discussed in this paper. Through the use of such design/evaluation approaches, it may be demonstrated that there is high likelihood that probabilistic performance goals can be achieved. 14 refs., 1 fig., 5 tabs.

  8. Materials Design On-the-Fly.

    PubMed

    Cerqueira, Tiago F T; Sarmiento-Pérez, Rafael; Amsler, Maximilian; Nogueira, F; Botti, Silvana; Marques, Miguel A L

    2015-08-11

    The dream of any solid-state theorist is to be able to predict new materials with tailored properties from scratch, i.e., without any input from experiment. Over the past decades, we have steadily approached this goal. Recent developments in the field of high-throughput calculations focused on finding the best material for specific applications. However, a key input for these techniques still had to be obtained experimentally, namely, the crystal structure of the materials. Here, we give a step further and show that one can indeed optimize material properties using as a single starting point the knowledge of the periodic table and the fundamental laws of quantum mechanics. This is done by combining state-of-the-art methods of global structure prediction that allow us to obtain the ground-state crystal structure of arbitrary materials, with an evolutionary algorithm that optimizes the chemical composition for the desired property. As a first showcase demonstration of our method, we perform an unbiased search for superhard materials and for transparent conductors. We stress that our method is completely general and can be used to optimize any property (or combination of properties) that can be calculated in a computer. PMID:26574474

  9. Material transformation designing shape changing interfaces enabled by programmable material anisotropy

    E-print Network

    Ou, Jifei

    2014-01-01

    This thesis takes a material perspective on designing transformable interfaces. The structure of material and mechanical properties such as stiffness, can determine not only its static performances, but also, with the help ...

  10. Concurrent materials and process selection in conceptual design

    SciTech Connect

    Kleban, S.D.

    1998-07-01

    The sequential manner in which materials and processes for a manufactured product are selected is inherently less than optimal. Designers` tendency to choose processes and materials with which they are familiar exacerbate this problem. A method for concurrent selection of materials and a joining process based on product requirements using a knowledge-based, constraint satisfaction approach is presented.

  11. Bridge : information as material for design

    E-print Network

    Kaijima, Sawako, 1976-

    2005-01-01

    This thesis investigates architectural design as a sensory device that mediates the relationship between the body and the environment. I used a bridge as a site since the body is fully exposed to an open environment, vet ...

  12. Material Design, Selection, and Manufacturing Methods for System Sustainment

    SciTech Connect

    David Sowder, Jim Lula, Curtis Marshall

    2010-02-18

    This paper describes a material selection and validation process proven to be successful for manufacturing high-reliability long-life product. The National Secure Manufacturing Center business unit of the Kansas City Plant (herein called KCP) designs and manufactures complex electrical and mechanical components used in extreme environments. The material manufacturing heritage is founded in the systems design to manufacturing practices that support the U.S. Department of Energy’s National Nuclear Security Administration (DOE/NNSA). Material Engineers at KCP work with the systems designers to recommend materials, develop test methods, perform analytical analysis of test data, define cradle to grave needs, present final selection and fielding. The KCP material engineers typically will maintain cost control by utilizing commercial products when possible, but have the resources and to develop and produce unique formulations as necessary. This approach is currently being used to mature technologies to manufacture materials with improved characteristics using nano-composite filler materials that will enhance system design and production. For some products the engineers plan and carry out science-based life-cycle material surveillance processes. Recent examples of the approach include refurbished manufacturing of the high voltage power supplies for cockpit displays in operational aircraft; dry film lubricant application to improve bearing life for guided munitions gyroscope gimbals, ceramic substrate design for electrical circuit manufacturing, and tailored polymeric materials for various systems. The following examples show evidence of KCP concurrent design-to-manufacturing techniques used to achieve system solutions that satisfy or exceed demanding requirements.

  13. Digital Alchemy for Materials Design and Optimization

    E-print Network

    van Anders, Greg; Karas, Andrew S; Dodd, Paul M; Glotzer, Sharon C

    2015-01-01

    Starting with the early alchemists, a holy grail of science has been to make desired materials by modifying the attributes of basic building blocks. Building blocks that show promise for assembling new complex materials can be synthesized at the nanoscale with attributes that would astonish the ancient alchemists in their versatility. However, this versatility means that making direct connection between building block attributes and bulk behavior is both necessary for rationally engineering materials, and difficult because building block attributes can be altered in many ways. Here we show how to exploit the malleability of the valence of colloidal nanoparticle "elements" to directly and quantitatively link building block attributes to bulk behavior through a statistical thermodynamic framework we term "digital alchemy". We use this framework to optimize building blocks for a given target structure, and to determine which building block attributes are most important to control for self assembly, through a set...

  14. Material Compatibility with Space Storable Propellants. Design Guidebook

    NASA Technical Reports Server (NTRS)

    Uney, P. E.; Fester, D. A.

    1972-01-01

    An important consideration in the design of spacecraft for interplanetary missions is the compatibility of storage materials with the propellants. Serious problems can arise because many propellants are either extremely reactive or subject to catalytic decomposition, making the selection of proper materials of construction for propellant containment and control a critical requirement for the long-life applications. To aid in selecting materials and designing and evaluating various propulsion subsystems, available information on the compatibility of spacecraft materials with propellants of interest was compiled from literature searches and personal contacts. The compatibility of both metals and nonmetals with hydrazine, monomethyl hydrazine, nitrated hydrazine, and diborance fuels and nitrogen tetroxide, fluorine, oxygen difluoride, and Flox oxidizers was surveyed. These fuels and oxidizers encompass the wide variety of problems encountered in propellant storage. As such, they present worst case situations of the propellant affecting the material and the material affecting the propellant. This includes material attack, propellant decomposition, and the formation of clogging materials.

  15. Designing Educative Curriculum Materials: A Theoretically and Empirically Driven Process

    ERIC Educational Resources Information Center

    Davis, Elizabeth A.; Palincsar, Annemarie Sullivan; Arias, Anna Maria; Bismack, Amber Schultz; Marulis, Loren M.; Iwashyna, Stefanie K.

    2014-01-01

    In this article, the authors argue for a design process in the development of educative curriculum materials that is theoretically and empirically driven. Using a design-based research approach, they describe their design process for incorporating educative features intended to promote teacher learning into existing, high-quality curriculum…

  16. Cultivating Design Thinking in Students through Material Inquiry

    ERIC Educational Resources Information Center

    Renard, Helene

    2014-01-01

    Design thinking is a way of understanding and engaging with the world that has received much attention in academic and business circles in recent years. This article examines a hands-on learning model as a vehicle for developing design thinking capacity in students. An overview of design thinking grounds the discussion of the material-based…

  17. Synthesis and Design of Silicide Intermetallic Materials

    SciTech Connect

    Petrovic, J.J.; Castro, R.G.; Vaidya, R.U.; Park, Y.

    1999-05-14

    The overall objective of this program is to develop structural silicide-based materials with optimum combinations of elevated temperature strength/creep resistance, low temperature fracture toughness, and high temperature oxidation and corrosion resistance for applications of importance to the US processing industry. A further objective is to develop silicide-based prototype industrial components. The ultimate aim of the program is to work with industry to transfer the structural silicide materials technology to the private sector in order to promote international competitiveness in the area of advanced high temperature materials and important applications in major energy-intensive US processing industries. The program presently has a number of industrial connections, including a CRADA with Johns Manville Corporation targeted at the area of MoSi{sub 2}-based high temperature materials for fiberglass melting and processing applications. The authors are also developing an interaction with the Institute of Gas Technology (IGT) to develop silicides for high temperature radiant gas burner applications, for the glass and other industries. With the Exotherm Corporation, they are developing advanced silicide powders for the fabrication of silicide materials with tailored and improved properties for industrial applications. In October 1998, the authors initiated a new activity funded by DOE/OIT on ``Molybdenum Disilicide Composites for Glass Processing Sensors''. With Accutru International Corporation, they are developing silicide-based protective sheaths for self-verifying temperature sensors which may be used in glass furnaces and other industrial applications. With Combustion Technology Inc., they are developing silicide-based periscope sight tubes for the direct observation of glass melts.

  18. Designing chromonic mesogens for the fabrication of anisotropic optical materials

    NASA Astrophysics Data System (ADS)

    Tam-Chang, Suk-Wah; Huang, Liming; Gyan, Aryal; Seo, Wonewoo; Mahinay, Delfin; Iverson, Isaac K.

    2008-02-01

    Perylene monoimides and diimides have applications as luminescent materials and in organic photovoltaic devices as chromophores and conducting materials. Materials in which these compounds are oriented in a preferred direction will possess useful anisotropic properties that are not attainable from materials in which the compounds are randomly oriented. Anisotropic materials of these compounds can be prepared by taking advantage of the unique properties of chromonic liquid crystals. In this paper we describe the principles for designing perylene monoimides and diimides with desired optical properties and chromonic liquid-crystalline properties. In addition, we demonstrate the fabrication of anisotropic optical materials via organization of these compounds into a lyotropic chromonic liquidcrystalline phase.

  19. Characterization of elastomeric materials with application to design

    NASA Technical Reports Server (NTRS)

    Bower, Mark V.

    1986-01-01

    Redesign of the Space Shuttle Solid Booster has necessitated re-evaluation of the material used in the field joint O-ring seals. The viscoelastic characteristics of five candidate materials were determined. The five materials are: two fluorocarbon compounds, two nitrile compounds, and a silicon compound. The materials were tested in a uniaxial compression test to determine the characteristic relaxation functions. These tests were performed at five different temperatures. A master material curve was developed for each material from the experimental data. The results are compared to tensile relaxation tests. Application of these results to the design analysis is discussed in detail.

  20. Nondestructive evaluation of composite materials - A design philosophy

    NASA Technical Reports Server (NTRS)

    Duke, J. C., Jr.; Henneke, E. G., II; Stinchcomb, W. W.; Reifsnider, K. L.

    1984-01-01

    Efficient and reliable structural design utilizing fiber reinforced composite materials may only be accomplished if the materials used may be nondestructively evaluated. There are two major reasons for this requirement: (1) composite materials are formed at the time the structure is fabricated and (2) at practical strain levels damage, changes in the condition of the material, that influence the structure's mechanical performance is present. The fundamental basis of such a nondestructive evaluation capability is presented. A discussion of means of assessing nondestructively the material condition as well as a damage mechanics theory that interprets the material condition in terms of its influence on the mechanical response, stiffness, strength and life is provided.

  1. Design with brittle materials - An interdisciplinary educational program

    NASA Technical Reports Server (NTRS)

    Mueller, J. I.; Bollard, R. J. H.; Hartz, B. J.; Kobayashi, A. S.; Love, W. J.; Scott, W. D.; Taggart, R.; Whittemore, O. J.

    1980-01-01

    A series of interdisciplinary design courses being offered to senior and graduate engineering students at the University of Washington is described. Attention is given to the concepts and some of the details on group design projects that have been undertaken during the past two years. It is noted that ceramic materials normally demonstrate a large scatter in strength properties. As a consequence, when designing with these materials, the conventional 'mil standards' design stresses with acceptable margins of safety cannot by employed and the designer is forced to accept a probable number of failures in structures of a given brittle material. It is this prediction of the probability of failure for structures of given, well-characterized materials that forms the basis for this series of courses.

  2. Bio-inspired design of intelligent materials

    NASA Astrophysics Data System (ADS)

    Taya, Minoru

    2003-07-01

    Several examples of sensors and actuators inherent in biological species are reviewed with emphasis on their mechanisms for a given set of stimuli. Examples include, action plants (Venus flytrap, Cucumber tendrils) and bamboo, and algae. Based on these examples and their mechanisms, we designed artificial actuators, FGM piezo actuators and electroactive polymer actuators.

  3. Digital Alchemy for Materials Design and Optimization

    E-print Network

    Greg van Anders; Daphne Klotsa; Andrew S. Karas; Paul M. Dodd; Sharon C. Glotzer

    2015-07-17

    Starting with the early alchemists, a holy grail of science has been to make desired materials by modifying the attributes of basic building blocks. Building blocks that show promise for assembling new complex materials can be synthesized at the nanoscale with attributes that would astonish the ancient alchemists in their versatility. However, this versatility means that making direct connection between building block attributes and bulk behavior is both necessary for rationally engineering materials, and difficult because building block attributes can be altered in many ways. Here we show how to exploit the malleability of the valence of colloidal nanoparticle "elements" to directly and quantitatively link building block attributes to bulk behavior through a statistical thermodynamic framework we term "digital alchemy". We use this framework to optimize building blocks for a given target structure, and to determine which building block attributes are most important to control for self assembly, through a set of novel thermodynamic response functions, moduli and susceptibilities. We thereby establish direct links between the attributes of colloidal building blocks and the bulk structures they form. Moreover, our results give concrete solutions to the more general conceptual challenge of optimizing emergent behaviors in nature, and can be applied to other types of matter. As examples, we apply digital alchemy to systems of truncated tetrahedra, rhombic dodecahedra, and isotropically interacting spheres that self assemble diamond, FCC, and icosahedral quasicrystal structures, respectively.

  4. Designing and modeling doubly porous polymeric materials

    NASA Astrophysics Data System (ADS)

    Ly, H.-B.; Le Droumaguet, B.; Monchiet, V.; Grande, D.

    2015-07-01

    Doubly porous organic materials based on poly(2-hydroxyethyl methacrylate) are synthetized through the use of two distinct types of porogen templates, namely a macroporogen and a nanoporogen. Two complementary strategies are implemented by using either sodium chloride particles or fused poly(methyl methacrylate) beads as macroporogens, in conjunction with ethanol as a porogenic solvent. The porogen removal respectively allows for the generation of either non-interconnected or interconnected macropores with an average diameter of about 100-200 ?m and nanopores with sizes lying within the 100 nm order of magnitude, as evidenced by mercury intrusion porosimetry and scanning electron microscopy. Nitrogen sorption measurements evidence the formation of materials with rather high specific surface areas, i.e. higher than 140 m2.g-1. This paper also addresses the development of numerical tools for computing the permeability of such doubly porous materials. Due to the coexistence of well separated scales between nanopores and macropores, a consecutive double homogenization approach is proposed. A nanoscopic scale and a mesoscopic scale are introduced, and the flow is evaluated by means of the Finite Element Method to determine the macroscopic permeability. At the nanoscopic scale, the flow is described by the Stokes equations with an adherence condition at the solid surface. At the mesoscopic scale, the flow obeys the Stokes equations in the macropores and the Darcy equation in the permeable polymer in order to account for the presence of the nanopores.

  5. The automated design of materials far from equilibrium

    NASA Astrophysics Data System (ADS)

    Miskin, Marc Z.

    Automated design is emerging as a powerful concept in materials science. By combining computer algorithms, simulations, and experimental data, new techniques are being developed that start with high level functional requirements and identify the ideal materials that achieve them. This represents a radically different picture of how materials become functional in which technological demand drives material discovery, rather than the other way around. At the frontiers of this field, materials systems previously considered too complicated can start to be controlled and understood. Particularly promising are materials far from equilibrium. Material robustness, high strength, self-healing and memory are properties displayed by several materials systems that are intrinsically out of equilibrium. These and other properties could be revolutionary, provided they can first be controlled. This thesis conceptualizes and implements a framework for designing materials that are far from equilibrium. We show how, even in the absence of a complete physical theory, design from the top down is possible and lends itself to producing physical insight. As a prototype system, we work with granular materials: collections of athermal, macroscopic identical objects, since these materials function both as an essential component of industrial processes as well as a model system for many non-equilibrium states of matter. We show that by placing granular materials in the context of design, benefits emerge simultaneously for fundamental and applied interests. As first steps, we use our framework to design granular aggregates with extreme properties like high stiffness, and softness. We demonstrate control over nonlinear effects by producing exotic aggregates that stiffen under compression. Expanding on our framework, we conceptualize new ways of thinking about material design when automatic discovery is possible. We show how to build rules that link particle shapes to arbitrary granular packing density. We examine how the results of a design process are contingent upon operating conditions by studying which shapes dissipate energy fastest in a granular gas. We even move to create optimization algorithms for the expressed purpose of material design, by integrating them with statistical mechanics. In all of these cases, we show that turning to machines puts a fresh perspective on materials far from equilibrium. By matching forms to functions, complexities become possibilities, motifs emerge that describe new physics, and the door opens to rational design.

  6. Materials for Digital Optical Design:. a Survey Study

    NASA Astrophysics Data System (ADS)

    Ismail, Ayman Abdel Khader; Ismail, Imane Aly Saroit; Ahmed, S. H.

    2010-04-01

    In the last few years digital optical design had major attention in research fields. Many researches were published in the fields of optical materials, instruments, circuit design and devices. This is considered to be the most multidisciplinary field and requires for its success collaborative efforts of many disciplines, ranging from device and optical engineers to computer architects, chemists, material scientists, and optical physicists. In this study we will introduce a survey of the latest papers in the field of optical materials and its properties for light; this paper is organized in three major sections, optical glasses, compound materials and nonlinear absorption (multi photon absorption) and up-conversion.

  7. Designing Radiation Resistance in Materials for Fusion Energy

    NASA Astrophysics Data System (ADS)

    Zinkle, S. J.; Snead, L. L.

    2014-07-01

    Proposed fusion and advanced (Generation IV) fission energy systems require high-performance materials capable of satisfactory operation up to neutron damage levels approaching 200 atomic displacements per atom with large amounts of transmutant hydrogen and helium isotopes. After a brief overview of fusion reactor concepts and radiation effects phenomena in structural and functional (nonstructural) materials, three fundamental options for designing radiation resistance are outlined: Utilize matrix phases with inherent radiation tolerance, select materials in which vacancies are immobile at the design operating temperatures, or engineer materials with high sink densities for point defect recombination. Environmental and safety considerations impose several additional restrictions on potential materials systems, but reduced-activation ferritic/martensitic steels (including thermomechanically treated and oxide dispersion-strengthened options) and silicon carbide ceramic composites emerge as robust structural materials options. Materials modeling (including computational thermodynamics) and advanced manufacturing methods are poised to exert a major impact in the next ten years.

  8. Photovoltaic module encapsulation design and materials selection, volume 1

    NASA Technical Reports Server (NTRS)

    Cuddihy, E.; Carroll, W.; Coulbert, C.; Gupta, A.; Liang, R. H.

    1982-01-01

    Encapsulation material system requirements, material selection criteria, and the status and properties of encapsulation materials and processes available are presented. Technical and economic goals established for photovoltaic modules and encapsulation systems and their status are described. Available encapsulation technology and data are presented to facilitate design and material selection for silicon flat plate photovoltaic modules, using the best materials available and processes optimized for specific power applications and geographic sites. The operational and environmental loads that encapsulation system functional requirements and candidate design concepts and materials that are identified to have the best potential to meet the cost and performance goals for the flat plate solar array project are described. Available data on encapsulant material properties, fabrication processing, and module life and durability characteristics are presented.

  9. Photovoltaic-module encapsulation design and materials selection: Volume 1

    SciTech Connect

    Cuddihy, E.; Carroll, W.; Coulbert, C.; Gupta, A.; Liang, R.

    1982-06-01

    Encapsulation-material system requirements, material-selection criteria, and the status and properties of encapsulation materials and processes available to the module manufacturer are presented in detail. Technical and economic goals established for photovoltaic modules and encapsulation systems and their status are described for material suppliers to assist them in assessing the suitability of materials in their product lines and the potential of new-material products. A comprehensive discussion of available encapsulation technology and data is presented to facilitate design and material selection for silicon flat-plate photovoltaic modules, using the best materials available and processes optimized for specific power applications and geographic sites. A basis is provided for specifying the operational and environmental loads that encapsulation material systems must resist. Potential deployment sites for which cost effectiveness may be achieved at a module price much greater than $0.70/W/sub p/, are also considered; data on higher-cost encapsulant materials and processes that may be in use and other material candidates that may be justified for special application are discussed. Described are encapsulation-system functional requirements and candidate design concepts and materials that have been identified and analyzed as having the best potential to meet the cost and performance goals for the Flat-Plate Solar Array Project. The available data on encapsulant material properties, fabrication processing, and module life and durability characteristics are presented.

  10. Computational materials design for energy applications

    NASA Astrophysics Data System (ADS)

    Ozolins, Vidvuds

    2013-03-01

    General adoption of sustainable energy technologies depends on the discovery and development of new high-performance materials. For instance, waste heat recovery and electricity generation via the solar thermal route require bulk thermoelectrics with a high figure of merit (ZT) and thermal stability at high-temperatures. Energy recovery applications (e.g., regenerative braking) call for the development of rapidly chargeable systems for electrical energy storage, such as electrochemical supercapacitors. Similarly, use of hydrogen as vehicular fuel depends on the ability to store hydrogen at high volumetric and gravimetric densities, as well as on the ability to extract it at ambient temperatures at sufficiently rapid rates. We will discuss how first-principles computational methods based on quantum mechanics and statistical physics can drive the understanding, improvement and prediction of new energy materials. We will cover prediction and experimental verification of new earth-abundant thermoelectrics, transition metal oxides for electrochemical supercapacitors, and kinetics of mass transport in complex metal hydrides. Research has been supported by the US Department of Energy under grant Nos. DE-SC0001342, DE-SC0001054, DE-FG02-07ER46433, and DE-FC36-08GO18136.

  11. First Principles Modeling for Research and Design of New Materials

    E-print Network

    Ceder, Gerbrand

    First principles computation can be used to investigate an design materials in ways that can not be achieved with experimental means. We show how computations can be used to rapidly capture the essential physics that ...

  12. Materials Process Design and Control Laboratory Cornell University

    E-print Network

    Zabaras, Nicholas J.

    parameters of two- phase nickel-based superalloy microstructures Uncertainty quantification of multiscale;Materials Process Design and Control Laboratory Cornell University Primary Development Employ model samples. Develop physics-based deterministic solvers to estimate mechanical properties

  13. Exploiting the dispersion of the double-negative-index fishnet metamaterial to create a broadband low-profile metallic lens.

    PubMed

    Orazbayev, B; Pacheco-Peña, V; Beruete, M; Navarro-Cía, M

    2015-04-01

    Metamaterial lenses with close values of permittivity and permeability usually display low reflection losses at the expense of narrow single frequency operation. Here, a broadband low-profile lens is designed by exploiting the dispersion of a fishnet metamaterial together with the zoning technique. The lens operates in a broadband regime from 54 GHz to 58 GHz, representing a fractional bandwidth ~7%, and outperforms Silicon lenses between 54 and 55.5 GHz. This broadband operation is demonstrated by a systematic analysis comprising Huygens-Fresnel analytical method, full-wave numerical simulations and experimental measurements at millimeter waves. For demonstrative purposes, a detailed study of the lens operation at two frequencies is done for the most important lens parameters (focal length, depth of focus, resolution, radiation diagram). Experimental results demonstrate diffraction-limited ~0.5? transverse resolution, in agreement with analytical and numerical calculations. In a lens antenna configuration, a directivity as high as 16.6 dBi is achieved. The different focal lengths implemented into a single lens could be potentially used for realizing the front end of a non-mechanical zoom millimeter-wave imaging system. PMID:25968693

  14. Evaluation of materials and design modifications for aircraft brakes

    NASA Technical Reports Server (NTRS)

    Ho, T. L.; Kennedy, F. E.; Peterson, M. B.

    1975-01-01

    A test program is described which was carried out to evaluate several proposed design modifications and several high-temperature friction materials for use in aircraft disk brakes. The evaluation program was carried out on a specially built test apparatus utilizing a disk brake and wheel half from a small het aircraft. The apparatus enabled control of brake pressure, velocity, and braking time. Tests were run under both constant and variable velocity conditions and covered a kinetic energy range similar to that encountered in aircraft brake service. The results of the design evaluation program showed that some improvement in brake performance can be realized by making design changes in the components of the brake containing friction material. The materials evaluation showed that two friction materials show potential for use in aircraft disk brakes. One of the materials is a nickel-based sintered composite, while the other is a molybdenum-based material. Both materials show much lower wear rates than conventional copper-based materials and are better able to withstand the high temperatures encountered during braking. Additional materials improvement is necessary since both materials show a significant negative slope of the friction-velocity curve at low velocities.

  15. Designing Radiation Resistance in Materials for Fusion Energy

    SciTech Connect

    Zinkle, Steven J; Snead, Lance Lewis

    2014-01-01

    Proposed fusion and advanced (Generation IV) fission energy systems require high performance materials capable of satisfactory operation up to neutron damage levels approaching 200 atomic displacements per atom with large amounts of transmutant hydrogen and helium isotopes. After a brief overview of fusion reactor concepts and radiation effects phenomena in structural and functional (non-structural) materials, three fundamental options for designing radiation resistance are outlined: Utilize matrix phases with inherent radiation tolerance, select materials where vacancies are immobile at the design operating temperatures, or construct high densities of point defect recombination sinks. Environmental and safety considerations impose several additional restrictions on potential materials systems, but reduced activation ferritic/martensitic steels (including thermomechanically treated and oxide dispersion strengthened options) and silicon carbide ceramic composites emerge as robust structural materials options. Materials modeling (including computational thermodynamics) and advanced manufacturing methods are poised to exert a major impact in the next ten years.

  16. Sculpture: Creative Designs with Modern Materials (Tentative Course Outline).

    ERIC Educational Resources Information Center

    Dubocq, Edward R.

    This document reports on a course in comprehension and application of various techniques of sculpture and collage, using a contemporary point of view. Students will work with contemporary materials such as wood, metals, plaster, plastics, styrofoam, and many other cardboard basic materials suitable for creative design products. This unit will…

  17. SUSTAINABLE INFRASTRUCTURE MATERIAL DESIGN Michael D. Lepech1

    E-print Network

    Lepech, Michael D.

    . Keoleian2 1 Advanced Civil Engineering Materials Research Laboratory Department of Civil and Environmental-oriented infrastructure systems. Yet incorporating these concepts into the design procedure as a primary goal remains of civil infrastructure systems linking the micron-length scale of material microstructural tailoring

  18. Center for Intelligent Fuel Cell Materials Design

    SciTech Connect

    Santurri, P.R.,; Hartmann-Thompson, C.; Keinath, S.E.

    2008-08-26

    The goal of this work was to develop a composite proton exchange membrane utilizing 1) readily available, low cost materials 2) readily modified and 3) easily processed to meet the chemical, mechanical and electrical requirements of high temperature PEM fuel cells. One of the primary goals was to produce a conducting polymer that met the criteria for strength, binding capability for additives, chemical stability, dimensional stability and good conductivity. In addition compatible, specialty nanoparticles were synthesized to provide water management and enhanced conductivity. The combination of these components in a multilayered, composite PEM has demonstrated improved conductivity at high temperatures and low humidity over commercially available polymers. The research reported in this final document has greatly increased the knowledge base related to post sulfonation of chemically and mechanically stable engineered polymers (Radel). Both electrical and strength factors for the degree of post sulfonation far exceed previous data, indicating the potential use of these materials in suitable proton exchange membrane architectures for the development of fuel cells. In addition compatible, hydrophilic, conductive nano-structures have been synthesized and incorporated into unique proton exchange membrane architectures. The use of post sulfonation for the engineered polymer and nano-particle provide cost effective techniques to produce the required components of a proton exchange membrane. The development of a multilayer proton exchange membrane as described in our work has produced a highly stable membrane at 170°C with conductivities exceeding commercially available proton exchange membranes at high temperatures and low humidity. The components and architecture of the proton exchange membrane discussed will provide low cost components for the portable market and potentially the transportation market. The development of unique components and membrane architecture provides a key element for the United States: 1) to transition the country from a fossil fuel based energy economy to a renewable energy based economy, and 2) to reduce our dependence on foreign oil. Developments of this program will serve as an important step toward continuing PEMFC technology and ultimately the broad-based commercial availability of this technology and its benefits.

  19. Distance Education: The Design of Study Materials. [Fifth Edition.

    ERIC Educational Resources Information Center

    Meacham, David; Evans, Deborah

    This guide is designed to provide a basis for the effective design of instructional materials for distance education. Organized around a model of instructional development which encompasses both external structural factors (factors that are largely outside the direct control of the individual instructor but which must be investigated) and internal…

  20. MaterialsProcessDesign and ControlLaboratory Cornell University

    E-print Network

    Zabaras, Nicholas J.

    Materials Process Design and Control Laboratory Sibley School of Mechanical and Aerospace Engineering 101-535 turbofan Nickel-base superalloy turbine disk Superalloy microstructure Sheared ' precipitates Pairs of edge and Design: An Information Theoretic Approach 4 Rolls-Royce RB211-535 turbofan Nickel-base superalloy turbine

  1. Rational design of inorganic dielectric materials with expected permittivity

    PubMed Central

    Xie, Congwei; Oganov, Artem R.; Dong, Dong; Liu, Ning; Li, Duan; Debela, Tekalign Terfa

    2015-01-01

    Techniques for rapid design of dielectric materials with appropriate permittivity for many important technological applications are urgently needed. It is found that functional structure blocks (FSBs) are helpful in rational design of inorganic dielectrics with expected permittivity. To achieve this, coordination polyhedra are parameterized as FSBs and a simple empirical model to evaluate permittivity based on these FSB parameters is proposed. Using this model, a wide range of examples including ferroelectric, high/low permittivity materials are discussed, resulting in several candidate materials for experimental follow-up. PMID:26617342

  2. Structural and Machine Design Using Piezoceramic Materials: A Guide for Structural Design Engineers

    NASA Technical Reports Server (NTRS)

    Inman, Daniel J.; Cudney, Harley H.

    2000-01-01

    Using piezoceramic materials is one way the design engineer can create structures which have an ability to both sense and respond to their environment. Piezoceramic materials can be used to create structural sensors and structural actuators. Because piezoceramic materials have transduction as a material property, their sensing or actuation functions are a result of what happens to the material. This is different than discrete devices we might attach to the structure. For example, attaching an accelerometer to a structure will yield an electrical signal proportional to the acceleration at the attachment point on the structure. Using a electromagnetic shaker as an actuator will create an applied force at the attachment point. Active material elements in a structural design are not easily modeled as providing transduction at a point, but rather they change the physics of the structure in the areas where they are used. Hence, a designer must not think of adding discrete devices to a structure to obtain an effect, but rather must design a structural system which accounts for the physical principles of all the elements in the structure. The purpose of this manual is to provide practicing engineers the information necessary to incorporate piezoelectric materials in structural design and machine design. First, we will review the solid-state physics of piezoelectric materials. Then we will discuss the physical characteristics of the electrical-active material-structural system. We will present the elements of this system which must be considered as part of the design task for a structural engineer. We will cover simple modeling techniques and review the features and capabilities of commercial design tools that are available. We will then cover practical how-to elements of working with piezoceramic materials. We will review sources of piezoceramic materials and built-up devices, and their characteristics. Finally, we will provide two design examples using piezoceramic materials, first as discrete actuators for vibration isolation, and second as structurally-distributed sensor/actuators for active acoustic control.

  3. Microstructural design of cellular materials I: Honeycomb beams and plates

    SciTech Connect

    Huang, J.S.; Gibson, L.J.

    1992-06-01

    Performance indices for materials describe the mechanical efficiency of a component under a given mode of loading: The higher the performance index, the lower the mass of the component for a given mechanical requirement. Material selection charts (Ashby, 1989) offer a graphical means of comparing performance indices for a wide range of materials. Performance indices are described. Micromechanical models for behaviour of cellular materials are used to suggest novel microstructural designs for cellular materials with improved performance. Three novel microstructural designs, described in companion papers, have been fabricated and tested. Results of the tests indicate that the new microstructures have higher values of some performance indices than those of the solids from which they are made.

  4. Materials of interaction : responsive materials in the design of transformable interactive surfaces

    E-print Network

    Coelho, Marcelo

    2008-01-01

    Materials that embody computational properties are reshaping the ways in which we design, interact and communicate. This thesis looks at the topic of form transformation and how to bring the programmability and versatility ...

  5. Design Exploration of Engineered Materials, Products, and Associated Manufacturing Processes

    NASA Astrophysics Data System (ADS)

    Shukla, Rishabh; Kulkarni, Nagesh H.; Gautham, B. P.; Singh, Amarendra K.; Mistree, Farrokh; Allen, Janet K.; Panchal, Jitesh H.

    2015-01-01

    In the past few years, ICME-related research has been directed towards the study of multi-scale materials design. However, relatively little has been reported on model-based methods that are of relevance to industry for the realization of engineered materials, products, and associated industrial manufacturing processes. Computational models used in the realization of engineered materials and products are fraught with uncertainty, have different levels of fidelity, are incomplete and are even likely to be inaccurate. In light of this, we adopt a robust design strategy that facilitates the exploration of the solution space thereby providing decision support to a design engineer. In this paper, we describe a foundational construct embodied in our method for design exploration, namely, the compromise Decision Support Problem. We introduce a problem that we are using to establish the efficacy of our method. It involves the integrated design of steel and gears, traversing the chain of steel making, mill production, and evolution of the material during these processes, and linking this to the mechanical design and manufacture of the gear. We provide an overview of our method to determine the operating set points for the ladle, tundish and caster operations necessary to manufacture steel of a desired set of properties. Finally, we highlight the efficacy of our method.

  6. Making the mid-infrared nano with designer plasmonic materials

    NASA Astrophysics Data System (ADS)

    Law, S.; Felts, J.; Roberts, C.; Podolskiy, V. A.; King, W. P.; Wasserman, D.

    2012-11-01

    Here we demonstrate a new class of designer plasmonic materials for use in the mid-infrared (mid-IR) region of the electromagnetic spectrum. By heavily doping epitaxially-grown semiconductor materials, we are able to grow single-crystal materials whose optical properties in the mid-IR mimic those of metals at shorter wavelengths. We demonstrate materials with plasma frequencies from 5.5-15?m and low losses, compared to their shortwavelength counterparts. In addition, we demonstrate the ability of subwavelength particles formed from our materials to support localized surface plasmon resonances, and measure the near-field absorption of these structures using a novel nanoscale infrared spectroscopy technique. Finally, we show good agreement between our observed results and analytical and finite-element models of our materials and structures. The results presented offer a path towards nanoscale confinement of light with micron-scale wavelengths.

  7. Microstructural design of cellular materials. 1: Honeycomb beams and plates

    SciTech Connect

    Huang, J.S.; Gibson, L.J.

    1995-04-01

    Performance indices for materials describe the mechanical efficiency of a component under a given mode of loading: the higher the performance index, the lower the mass of the component for a given mechanical requirement. Material selection charts offer a graphical means of comparing performance indices for a wide range of materials. The performance indices are first described. Micromechanical models for the behavior of cellular materials are then used to suggest novel microstructural designs for cellular materials with improved performance. Model materials with two of the microstructures, honeycomb beams and plates, have been fabricated and tested. The results of the tests indicate that the new microstructures have higher values of some performance indices than those of the solids from which they are made.

  8. 46 CFR 128.230 - Penetrations of hulls and watertight bulkheads-materials and pressure design.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...watertight bulkheads-materials and pressure design. 128.230 Section 128.230 Shipping...EQUIPMENT AND SYSTEMS Materials and Pressure Design § 128.230 Penetrations of hulls...watertight bulkheads—materials and pressure design. (a) Each piping...

  9. 46 CFR 128.220 - Class II non-vital systems-materials and pressure design.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...non-vital systems-materials and pressure design. 128.220 Section 128.220 ...AND SYSTEMS Materials and Pressure Design § 128.220 Class II non-vital systems—materials and pressure design. (a) Except as provided...

  10. 14 CFR 23.613 - Material strength properties and design values.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...false Material strength properties and design values. 23.613 Section 23.613...ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction § 23.613 Material strength properties and design values. (a) Material...

  11. Conceptual Design Report for the Irradiated Materials Characterization Laboratory (IMCL)

    SciTech Connect

    Stephanie Austad

    2010-06-01

    This document describes the design at a conceptual level for the Irradiated Materials Characterization Laboratory (IMCL) to be located at the Materials and Fuels Complex (MFC) at the Idaho National Laboratory (INL). The IMCL is an 11,000-ft2, Hazard Category-2 nuclear facility that is designed for use as a state of the-art nuclear facility for the purpose of hands-on and remote handling, characterization, and examination of irradiated and nonirradiated nuclear material samples. The IMCL will accommodate a series of future, modular, and reconfigurable instrument enclosures or caves. To provide a bounding design basis envelope for the facility-provided space and infrastructure, an instrument enclosure or cave configuration was developed and is described in some detail. However, the future instrument enclosures may be modular, integral with the instrument, or reconfigurable to enable various characterization environments to be configured as changes in demand occur. They are not provided as part of the facility.

  12. Optimal design of piezoelectric materials and devices for energy harvesting

    NASA Astrophysics Data System (ADS)

    Kim, Miso; Dugundji, John; Wardle, Brian L.

    2013-06-01

    Piezoelectric vibration energy harvesters (PVEHs) have received considerable attention as an enabling technology for self-powered wireless sensor networks. However, the biggest challenge with PVEHs has been their insufficient power generation for practical applications, which necessitates creative and disruptive materials and structure design on various scales. In this work, a model-based design study is performed that includes structural, materials, and device-level power optimizations of PVEHs. The optimization results help in understanding the behavior of the device performance, such as voltage and power, when the devices are optimized under various operating conditions, including input operating frequencies and mechanical damping. Furthermore, the optimization provides both an optimal device design scheme for power improvement and a better understanding of the correlation between the material property and the energy-harvesting output performance.

  13. 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.

  14. Modular design in natural and biomimetic soft materials.

    PubMed

    Kushner, Aaron M; Guan, Zhibin

    2011-09-19

    Under eons of evolutionary and environmental pressure, biological systems have developed strong and lightweight peptide-based polymeric materials by using the 20 naturally occurring amino acids as principal monomeric units. These materials outperform their man-made counterparts in the following ways: 1) multifunctionality/tunability, 2) adaptability/stimuli-responsiveness, 3) synthesis and processing under ambient and aqueous conditions, and 4) recyclability and biodegradability. The universal design strategy that affords these advanced properties involves "bottom-up" synthesis and modular, hierarchical organization both within and across multiple length-scales. The field of "biomimicry"-elucidating and co-opting nature's basic material design principles and molecular building blocks-is rapidly evolving. This Review describes what has been discovered about the structure and molecular mechanisms of natural polymeric materials, as well as the progress towards synthetic "mimics" of these remarkable systems. PMID:21898722

  15. Soft computing in design and manufacturing of advanced materials

    NASA Technical Reports Server (NTRS)

    Cios, Krzysztof J.; Baaklini, George Y; Vary, Alex

    1993-01-01

    The potential of fuzzy sets and neural networks, often referred to as soft computing, for aiding in all aspects of manufacturing of advanced materials like ceramics is addressed. In design and manufacturing of advanced materials, it is desirable to find which of the many processing variables contribute most to the desired properties of the material. There is also interest in real time quality control of parameters that govern material properties during processing stages. The concepts of fuzzy sets and neural networks are briefly introduced and it is shown how they can be used in the design and manufacturing processes. These two computational methods are alternatives to other methods such as the Taguchi method. The two methods are demonstrated by using data collected at NASA Lewis Research Center. Future research directions are also discussed.

  16. Segmented molecular design of self-healing proteinaceous materials

    NASA Astrophysics Data System (ADS)

    Sariola, Veikko; Pena-Francesch, Abdon; Jung, Huihun; Çetinkaya, Murat; Pacheco, Carlos; Sitti, Metin; Demirel, Melik C.

    2015-09-01

    Hierarchical assembly of self-healing adhesive proteins creates strong and robust structural and interfacial materials, but understanding of the molecular design and structure-property relationships of structural proteins remains unclear. Elucidating this relationship would allow rational design of next generation genetically engineered self-healing structural proteins. Here we report a general self-healing and -assembly strategy based on a multiphase recombinant protein based material. Segmented structure of the protein shows soft glycine- and tyrosine-rich segments with self-healing capability and hard beta-sheet segments. The soft segments are strongly plasticized by water, lowering the self-healing temperature close to body temperature. The hard segments self-assemble into nanoconfined domains to reinforce the material. The healing strength scales sublinearly with contact time, which associates with diffusion and wetting of autohesion. The finding suggests that recombinant structural proteins from heterologous expression have potential as strong and repairable engineering materials.

  17. Segmented molecular design of self-healing proteinaceous materials.

    PubMed

    Sariola, Veikko; Pena-Francesch, Abdon; Jung, Huihun; Çetinkaya, Murat; Pacheco, Carlos; Sitti, Metin; Demirel, Melik C

    2015-01-01

    Hierarchical assembly of self-healing adhesive proteins creates strong and robust structural and interfacial materials, but understanding of the molecular design and structure-property relationships of structural proteins remains unclear. Elucidating this relationship would allow rational design of next generation genetically engineered self-healing structural proteins. Here we report a general self-healing and -assembly strategy based on a multiphase recombinant protein based material. Segmented structure of the protein shows soft glycine- and tyrosine-rich segments with self-healing capability and hard beta-sheet segments. The soft segments are strongly plasticized by water, lowering the self-healing temperature close to body temperature. The hard segments self-assemble into nanoconfined domains to reinforce the material. The healing strength scales sublinearly with contact time, which associates with diffusion and wetting of autohesion. The finding suggests that recombinant structural proteins from heterologous expression have potential as strong and repairable engineering materials. PMID:26323335

  18. Segmented molecular design of self-healing proteinaceous materials

    PubMed Central

    Sariola, Veikko; Pena-Francesch, Abdon; Jung, Huihun; Çetinkaya, Murat; Pacheco, Carlos; Sitti, Metin; Demirel, Melik C.

    2015-01-01

    Hierarchical assembly of self-healing adhesive proteins creates strong and robust structural and interfacial materials, but understanding of the molecular design and structure–property relationships of structural proteins remains unclear. Elucidating this relationship would allow rational design of next generation genetically engineered self-healing structural proteins. Here we report a general self-healing and -assembly strategy based on a multiphase recombinant protein based material. Segmented structure of the protein shows soft glycine- and tyrosine-rich segments with self-healing capability and hard beta-sheet segments. The soft segments are strongly plasticized by water, lowering the self-healing temperature close to body temperature. The hard segments self-assemble into nanoconfined domains to reinforce the material. The healing strength scales sublinearly with contact time, which associates with diffusion and wetting of autohesion. The finding suggests that recombinant structural proteins from heterologous expression have potential as strong and repairable engineering materials. PMID:26323335

  19. Concurrent materials and process selection in conceptual design

    SciTech Connect

    Kleban, Stephen D.; Knorovsky, Gerald A.

    2000-08-16

    A method for concurrent selection of materials and a joining process based on product requirements using a knowledge-based, constraint satisfaction approach facilitates the product design and manufacturing process. Using a Windows-based computer video display and a data base of materials and their properties, the designer can ascertain the preferred composition of two parts based on various operating/environmental constraints such as load, temperature, lifetime, etc. Optimum joinder of the two parts may simultaneously be determined using a joining process data base based upon the selected composition of the components as well as the operating/environmental constraints.

  20. Optimum weight design of functionally graded material gears

    NASA Astrophysics Data System (ADS)

    Jing, Shikai; Zhang, He; Zhou, Jingtao; Song, Guohua

    2015-10-01

    Traditional gear weight optimization methods consider gear tooth number, module, face width or other dimension parameters of gear as design variables. However, due to the complicated form and geometric features peculiar to the gear, there will be large amounts of design parameters in gear design, and the influences of gear parameters changing on gear trains, transmission system and the whole equipment have to be taken into account, which increases the complexity of optimization problem. This paper puts forward to apply functionally graded materials (FGMs) to gears and then conduct the optimization. According to the force situation of gears, the material distribution form of FGM gears is determined. Then based on the performance parameters analysis of FGMs and the practical working demands for gears, a multi-objective optimization model is formed. Finally by using the goal driven optimization (GDO) method, the optimal material distribution is achieved, which makes gear weight and the maximum deformation be minimum and the maximum bending stress do not exceed the allowable stress. As an example, the applying of FGM to automotive transmission gear is conducted to illustrate the optimization design process and the result shows that under the condition of keeping the normal working performance of gear, the method achieves in greatly reducing the gear weight. This research proposes a FGM gears design method that is able to largely reduce the weight of gears by optimizing the microscopic material parameters instead of changing the macroscopic dimension parameters of gears, which reduces the complexity of gear weight optimization problem.

  1. LUTE primary mirror materials and design study report

    NASA Technical Reports Server (NTRS)

    Ruthven, Greg

    1993-01-01

    The major objective of the Lunar Ultraviolet Telescope Experiment (LUTE) Primary Mirror Materials and Design Study is to investigate the feasibility of the LUTE telescope primary mirror. A systematic approach to accomplish this key goal was taken by first understanding the optical, thermal, and structural requirements and then deriving the critical primary mirror-level requirements for ground testing, launch, and lunar operations. After summarizing the results in those requirements which drove the selection of material and the design for the primary mirror are discussed. Most important of these are the optical design which was assumed to be the MSFC baseline (i.e. 3 mirror optical system), telescope wavefront error (WFE) allocations, the telescope weight budget, and the LUTE operational temperature ranges. Mechanical load levels, reflectance and microroughness issues, and options for the LUTE metering structure were discussed and an outline for the LUTE telescope sub-system design specification was initiated. The primary mirror analysis and results are presented. The six material substrate candidates are discussed and four distinct mirror geometries which are considered are shown. With these materials and configurations together with varying the location of the mirror support points, a total of 42 possible primary mirror designs resulted. The polishability of each substrate candidate was investigated and a usage history of 0.5 meter and larger precision cryogenic mirrors (the operational low end LUTE temperature of 60 K is the reason we feel a survey of cryogenic mirrors is appropriate) that were flown or tested are presented.

  2. The Cam Shell: An Innovative Design With Materials and Manufacturing

    NASA Technical Reports Server (NTRS)

    Chung, W. Richard; Larsen, Frank M.; Kornienko, Rob

    2003-01-01

    Most of the personal audio and video recording devices currently sold on the open market all require hands to operate. Little consideration was given to designing a hands-free unit. Such a system once designed and made available to the public could greatly benefit mobile police officers, bicyclists, adventurers, street and dirt motorcyclists, horseback riders and many others. With a few design changes water sports and skiing activities could be another large area of application. The cam shell is an innovative design in which an audio and video recording device (such as palm camcorder) is housed in a body-mounted protection system. This system is based on the concept of viewing and recording at the same time. A view cam is attached to a helmet wired to a recording unit encased in a transparent body-mounted protection system. The helmet can also be controlled by remote. The operator will have full control in recording everything. However, the recording unit will be operated completely hands-free. This project will address the design considerations and their effects on material selection and manufacturing. It will enhance the understanding of the structure of materials, and how the structure affects the behavior of the material, and the role that processing play in linking the relationship between structure and properties. A systematic approach to design feasibility study, cost analysis and problem solving will also be discussed.

  3. Turning statistical physics models into materials design engines.

    PubMed

    Miskin, Marc Z; Khaira, Gurdaman; de Pablo, Juan J; Jaeger, Heinrich M

    2016-01-01

    Despite the success statistical physics has enjoyed at predicting the properties of materials for given parameters, the inverse problem, identifying which material parameters produce given, desired properties, is only beginning to be addressed. Recently, several methods have emerged across disciplines that draw upon optimization and simulation to create computer programs that tailor material responses to specified behaviors. However, so far the methods developed either involve black-box techniques, in which the optimizer operates without explicit knowledge of the material's configuration space, or require carefully tuned algorithms with applicability limited to a narrow subclass of materials. Here we introduce a formalism that can generate optimizers automatically by extending statistical mechanics into the realm of design. The strength of this approach lies in its capability to transform statistical models that describe materials into optimizers to tailor them. By comparing against standard black-box optimization methods, we demonstrate how optimizers generated by this formalism can be faster and more effective, while remaining straightforward to implement. The scope of our approach includes possibilities for solving a variety of complex optimization and design problems concerning materials both in and out of equilibrium. PMID:26684770

  4. Fragema fuel design progress in materials and concepts

    SciTech Connect

    Silberstein, A.J.

    1993-12-31

    Constant search for fuel design progress in materials and concepts is a must in order to supply to PWR plant operators a product which is more reliable and more conducive to cycle cost reduction. This paper demonstrates the actions taken by Fragema to fulfil these permanent objectives over a period of time ranging from 1985 to 1995.

  5. Bio-inspired Design of Intelligent Materials Minoru Taya*

    E-print Network

    Taya, Minoru

    are reviewed with emphasis on their mechanisms for a given set of stimuli. Examples include, action plants: Bio-inspired design, intelligent materials, action plants, functionally graded microstructure, bumboo controlled responses, which do not require or the remote control by a central nervous system. We look

  6. Designed amyloid fibers as materials for selective carbon dioxide capture

    E-print Network

    Yaghi, Omar M.

    of water, in both a natural amyloid and designed amyloids having increased carbon dioxide capacity. Heating, and volatile nature of MEA (4). More importantly, because of the high heat capacity of aqueous MEA solutions of functional materials (19­23). Results Functionalizing Natural VQIVYK Amyloid Fiber for Carbon Dioxide Capture

  7. Design of nanoporous materials with optimal sorption capacity

    NASA Astrophysics Data System (ADS)

    Zhang, Xuan; Urita, Koki; Moriguchi, Isamu; Tartakovsky, Daniel M.

    2015-06-01

    Modern technological advances have enabled one to manufacture nanoporous materials with a prescribed pore structure. This raises a possibility of using controllable pore-scale parameters (e.g., pore size and connectivity) to design materials with desired macroscopic properties (e.g., diffusion coefficient and adsorption capacity). By relating these two scales, the homogenization theory (or other upscaling techniques) provides a means of guiding the experimental design. To demonstrate this approach, we consider a class of nanoporous materials whose pore space consists of nanotunnels interconnected by nanotube bridges. Such hierarchical nanoporous carbons with mesopores and micropores have shown high specific electric double layer capacitances and high rate capability in an organic electrolyte. We express the anisotropic diffusion coefficient and adsorption coefficient of such materials in terms of the tunnels' properties (pore radius and inter-pore throat width) and their connectivity (spacing between the adjacent tunnels and nanotube-bridge density). Our analysis is applicable for solutes that undergo a non-equilibrium Langmuir adsorption reaction on the surfaces of fluid-filled pores, but other homogeneous and heterogeneous reactions can be handled in a similar fashion. The presented results can be used to guide the design of nanoporous materials with optimal permeability and sorption capacity.

  8. Materials design data for reduced activation martensitic steel type EUROFER

    NASA Astrophysics Data System (ADS)

    Tavassoli, A.-A. F.; Alamo, A.; Bedel, L.; Forest, L.; Gentzbittel, J.-M.; Rensman, J.-W.; Diegele, E.; Lindau, R.; Schirra, M.; Schmitt, R.; Schneider, H. C.; Petersen, C.; Lancha, A.-M.; Fernandez, P.; Filacchioni, G.; Maday, M. F.; Mergia, K.; Boukos, N.; Baluc; Spätig, P.; Alves, E.; Lucon, E.

    2004-08-01

    Materials design limits derived so far from the data generated in Europe for the reduced activation ferritic/martensitic (RAFM) steel type Eurofer are presented. These data address the short-term needs of the ITER Test Blanket Modules and a DEMOnstration fusion reactor. Products tested include plates, bars, tubes, TIG and EB welds, as well as powder consolidated blocks and solid-solid HIP joints. Effects of thermal ageing and low dose neutron irradiation are also included. Results are sorted and screened according to design code requirements before being introduced in reference databases. From the physical properties databases, variations of magnetic properties, modulus of elasticity, density, thermal conductivity, thermal diffusivity, specific heat, mean and instantaneous linear coefficients of thermal expansion versus temperature are derived. From the tensile and creep properties databases design allowable stresses are derived. From the instrumented Charpy impact and fracture toughness databases, ductile to brittle transition temperature, toughness and behavior of materials in different fracture modes are evaluated. From the fatigue database, total strain range versus number of cycles to failure curves are plotted and used to derive fatigue design curves. Cyclic curves are also derived and compared with monotonic hardening curves. Finally, irradiated and aged materials data are compared to ensure that the safety margins incorporated in unirradiated design limits are not exceeded.

  9. CubeSat Material Limits For Design for Demise

    NASA Technical Reports Server (NTRS)

    Kelley, R. L.; Jarkey, D. R.

    2014-01-01

    The CubeSat form factor of nano-satellite (a satellite with a mass between one and ten kilograms) has grown in popularity due to their ease of construction and low development and launch costs. In particular, their use as student led payload design projects has increased due to the growing number of launch opportunities. CubeSats are often deployed as secondary or tertiary payloads on most US launch vehicles or they may be deployed from the ISS. The focus of this study will be on CubeSats launched from the ISS. From a space safety standpoint, the development and deployment processes for CubeSats differ significantly from that of most satellites. For large satellites, extensive design reviews and documentation are completed, including assessing requirements associated with reentry survivability. Typical CubeSat missions selected for ISS deployment have a less rigorous review process that may not evaluate aspects beyond overall design feasibility. CubeSat design teams often do not have the resources to ensure their design is compliant with reentry risk requirements. A study was conducted to examine methods to easily identify the maximum amount of a given material that can be used in the construction of a CubeSats without posing harm to persons on the ground. The results demonstrate that there is not a general equation or relationship that can be used for all materials; instead a limiting value must be defined for each unique material. In addition, the specific limits found for a number of generic materials that have been previously used as benchmarking materials for reentry survivability analysis tool comparison will be discussed.

  10. CubeSat Material Limits for Design for Demise

    NASA Technical Reports Server (NTRS)

    Kelley, R. L.; Jarkey, D. R.

    2014-01-01

    The CubeSat form factor of nano-satellite (a satellite with a mass between one and ten kilograms) has grown in popularity due to their ease of construction and low development and launch costs. In particular, their use as student led payload design projects has increased due to the growing number of launch opportunities. CubeSats are often deployed as secondary or tertiary payloads on most US launch vehicles or they may be deployed from the ISS. The focus of this study will be on CubeSats launched from the ISS. From a space safety standpoint, the development and deployment processes for CubeSats differ significantly from that of most satellites. For large satellites, extensive design reviews and documentation are completed, including assessing requirements associated with re-entry survivability. Typical CubeSat missions selected for ISS deployment have a less rigorous review process that may not evaluate aspects beyond overall design feasibility. CubeSat design teams often do not have the resources to ensure their design is compliant with re-entry risk requirements. A study was conducted to examine methods to easily identify the maximum amount of a given material that can be used in the construction of a CubeSats without posing harm to persons on the ground. The results demonstrate that there is not a general equation or relationship that can be used for all materials; instead a limiting value must be defined for each unique material. In addition, the specific limits found for a number of generic materials that have been previously used as benchmarking materials for re-entry survivability analysis tool comparison will be discussed.

  11. The radioactive materials packaging handbook: Design, operations, and maintenance

    SciTech Connect

    Shappert, L.B.; Bowman, S.M.; Arnold, E.D.

    1998-08-01

    As part of its required activities in 1994, the US Department of Energy (DOE) made over 500,000 shipments. Of these shipments, approximately 4% were hazardous, and of these, slightly over 1% (over 6,400 shipments) were radioactive. Because of DOE`s cleanup activities, the total quantities and percentages of radioactive material (RAM) that must be moved from one site to another is expected to increase in the coming years, and these materials are likely to be different than those shipped in the past. Irradiated fuel will certainly be part of the mix as will RAM samples and waste. However, in many cases these materials will be of different shape and size and require a transport packaging having different shielding, thermal, and criticality avoidance characteristics than are currently available. This Handbook provides guidance on the design, testing, certification, and operation of packages for these materials.

  12. Rational material design for ultrafast rechargeable lithium-ion batteries.

    PubMed

    Tang, Yuxin; Zhang, Yanyan; Li, Wenlong; Ma, Bing; Chen, Xiaodong

    2015-10-01

    Rechargeable lithium-ion batteries (LIBs) are important electrochemical energy storage devices for consumer electronics and emerging electrical/hybrid vehicles. However, one of the formidable challenges is to develop ultrafast charging LIBs with the rate capability at least one order of magnitude (>10 C) higher than that of the currently commercialized LIBs. This tutorial review presents the state-of-the-art developments in ultrafast charging LIBs by the rational design of materials. First of all, fundamental electrochemistry and related ionic/electronic conduction theories identify that the rate capability of LIBs is kinetically limited by the sluggish solid-state diffusion process in electrode materials. Then, several aspects of the intrinsic materials, materials engineering and processing, and electrode materials architecture design towards maximizing both ionic and electronic conductivity in the electrode with a short diffusion length are deliberated. Finally, the future trends and perspectives for the ultrafast rechargeable LIBs are discussed. Continuous rapid progress in this area is essential and urgent to endow LIBs with ultrafast charging capability to meet huge demands in the near future. PMID:25857819

  13. Bioinspiration from fish for smart material design and function

    NASA Astrophysics Data System (ADS)

    Lauder, G. V.; Madden, P. G. A.; Tangorra, J. L.; Anderson, E.; Baker, T. V.

    2011-09-01

    Fish are a potentially rich source of inspiration for the design of smart materials. Fish exemplify the use of flexible materials to generate forces during locomotion, and a hallmark of fish functional design is the use of body and fin deformation to power propulsion and maneuvering. As a result of nearly 500 million years of evolutionary experimentation, fish design has a number of interesting features of note to materials engineers. In this paper we first provide a brief general overview of some key features of the mechanical design of fish, and then focus on two key properties of fish: the bilaminar mechanical design of bony fish fin rays that allows active muscular control of curvature, and the role of body flexibility in propulsion. After describing the anatomy of bony fish fin rays, we provide new data on their mechanical properties. Three-point bending tests and measurement of force inputs to and outputs from the fin rays show that these fin rays are effective displacement transducers. Fin rays in different regions of the fin differ considerably in their material properties, and in the curvature produced by displacement of one of the two fin ray halves. The mean modulus for the proximal (basal) region of the fin rays was 1.34 GPa, but this varied from 0.24 to 3.7 GPa for different fin rays. The distal fin region was less stiff, and moduli for the different fin rays measured varied from 0.11 to 0.67 GPa. These data are similar to those for human tendons (modulus around 0.5 GPa). Analysis of propulsion using flexible foils controlled using a robotic flapping device allows investigation of the effect of altering flexural stiffness on swimming speed. Flexible foils with the leading edge moved in a heave show a distinct peak in propulsive performance, while the addition of pitch input produces a broad plateau where the swimming speed is relatively unaffected by the flexural stiffness. Our understanding of the material design of fish and the control of tissue stiffness is still in its infancy, and the development of smart materials to assist in investigating the active control of stiffness and in the construction of robotic fish-like devices is a key challenge for the near future.

  14. Photovoltaic module encapsulation design and materials selection. Volume II

    SciTech Connect

    Cuddihy, E.

    1984-06-01

    This is Volume II of Photovoltaic Module Encapsulation Design and Materials Selection: a periodically updated handbook of encapsulation technology, developed with the support of the Flat-Plate Solar Array Project (FSA), managed for the Department of Energy (DOE) by the Jet Propulsion Laboratory. Volume II describes FSA encapsulation technology developed between June 1, 1982, and January 1, 1984. Emphasis during this period shifted from materials development to demonstration of reliability and durability in an outdoor environment; the updated information in this volume reflects the developing technology base related to both reliability and encapsulation process improvements.

  15. Designed amyloid fibers as materials for selective carbon dioxide capture

    PubMed Central

    Li, Dan; Furukawa, Hiroyasu; Deng, Hexiang; Liu, Cong; Yaghi, Omar M.; Eisenberg, David S.

    2014-01-01

    New materials capable of binding carbon dioxide are essential for addressing climate change. Here, we demonstrate that amyloids, self-assembling protein fibers, are effective for selective carbon dioxide capture. Solid-state NMR proves that amyloid fibers containing alkylamine groups reversibly bind carbon dioxide via carbamate formation. Thermodynamic and kinetic capture-and-release tests show the carbamate formation rate is fast enough to capture carbon dioxide by dynamic separation, undiminished by the presence of water, in both a natural amyloid and designed amyloids having increased carbon dioxide capacity. Heating to 100 °C regenerates the material. These results demonstrate the potential of amyloid fibers for environmental carbon dioxide capture. PMID:24367077

  16. Design of a materials testing experiment for the INTOR

    SciTech Connect

    Vogel, M.A.; Opperman, E.K.

    1981-08-28

    The United States, Japan, USSR and the European community are jointly participating in the design of an International Tokamak Reactor called INTOR. In support of the US contribution to the INTOR design, the features of an experiment for bulk neutron irradiation damage studies were developed. It is anticipated that materials testing will be an important part of the programmatic mission of INTOR and consequently the requirements for materials testing in INTOR must be identified early in the reactor design to insure compatibility. The design features of the experiment, called a Channel Test, are given in this paper. The major components of the channel test are the water cooled heat sink (channel module) and the specimen capsule. The temperature within each of the 153 specimen capsules is predetermined by engineering the thermal barrier between the specimen capsule and heat sink. Individual capsules can be independently accessed and are designed to operate at a predetermined temperature within the range of 50 to 700/sup 0/C. The total irradiation volume within a single channel test is 45 liters. Features of the channel test that result in experimental versatility and simplified remote access and handling are discussed.

  17. A model for designing functionally gradient material joints

    SciTech Connect

    Messler, R.W. Jr.; Jou, M.; Orling, T.T.

    1995-05-01

    An analytical, thin-plate layer model was developed to assist research and development engineers in the design of functionally gradient material (FGM) joints consisting of discrete steps between end elements of dissimilar materials. Such joints have long been produced by diffusion bonding using intermediates or multiple interlayers; welding, brazing or soldering using multiple transition pieces; and glass-to-glass or glass-to-metal bonding using multiple layers to produce matched seals. More recently, FGM joints produced by self-propagating high-temperature synthesis (SHS) are attracting the attention of researchers. The model calculates temperature distributions and associated thermally induced stresses, assuming elastic behavior, for any number of layers of any thickness or composition, accounting for critically important thermophysical properties in each layer as functions of temperature. It is useful for assuring that cured-in fabrication stresses from thermal expansion mismatches will not prevent quality joint production. The model`s utility is demonstrated with general design cases.

  18. Rational Design of Pathogen-Mimicking Amphiphilic Materials as Nanoadjuvants

    NASA Astrophysics Data System (ADS)

    Ulery, Bret D.; Petersen, Latrisha K.; Phanse, Yashdeep; Kong, Chang Sun; Broderick, Scott R.; Kumar, Devender; Ramer-Tait, Amanda E.; Carrillo-Conde, Brenda; Rajan, Krishna; Wannemuehler, Michael J.; Bellaire, Bryan H.; Metzger, Dennis W.; Narasimhan, Balaji

    2011-12-01

    An opportunity exists today for cross-cutting research utilizing advances in materials science, immunology, microbial pathogenesis, and computational analysis to effectively design the next generation of adjuvants and vaccines. This study integrates these advances into a bottom-up approach for the molecular design of nanoadjuvants capable of mimicking the immune response induced by a natural infection but without the toxic side effects. Biodegradable amphiphilic polyanhydrides possess the unique ability to mimic pathogens and pathogen associated molecular patterns with respect to persisting within and activating immune cells, respectively. The molecular properties responsible for the pathogen-mimicking abilities of these materials have been identified. The value of using polyanhydride nanovaccines was demonstrated by the induction of long-lived protection against a lethal challenge of Yersinia pestis following a single administration ten months earlier. This approach has the tantalizing potential to catalyze the development of next generation vaccines against diseases caused by emerging and re-emerging pathogens.

  19. Exascale Co-design for Modeling Materials in Extreme Environments

    SciTech Connect

    Germann, Timothy C.

    2014-07-08

    Computational materials science has provided great insight into the response of materials under extreme conditions that are difficult to probe experimentally. For example, shock-induced plasticity and phase transformation processes in single-crystal and nanocrystalline metals have been widely studied via large-scale molecular dynamics simulations, and many of these predictions are beginning to be tested at advanced 4th generation light sources such as the Advanced Photon Source (APS) and Linac Coherent Light Source (LCLS). I will describe our simulation predictions and their recent verification at LCLS, outstanding challenges in modeling the response of materials to extreme mechanical and radiation environments, and our efforts to tackle these as part of the multi-institutional, multi-disciplinary Exascale Co-design Center for Materials in Extreme Environments (ExMatEx). ExMatEx has initiated an early and deep collaboration between domain (computational materials) scientists, applied mathematicians, computer scientists, and hardware architects, in order to establish the relationships between algorithms, software stacks, and architectures needed to enable exascale-ready materials science application codes within the next decade. We anticipate that we will be able to exploit hierarchical, heterogeneous architectures to achieve more realistic large-scale simulations with adaptive physics refinement, and are using tractable application scale-bridging proxy application testbeds to assess new approaches and requirements. Such current scale-bridging strategies accumulate (or recompute) a distributed response database from fine-scale calculations, in a top-down rather than bottom-up multiscale approach.

  20. 30 CFR 18.20 - Quality of material, workmanship, and design.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Quality of material, workmanship, and design. 18.20 Section 18.20 Mineral...EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.20 Quality of material, workmanship, and design. (a) Electrically operated...

  1. 30 CFR 27.20 - Quality of material, workmanship, and design.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Quality of material, workmanship, and design. 27.20 Section 27.20 Mineral...METHANE-MONITORING SYSTEMS Construction and Design Requirements § 27.20 Quality of material, workmanship, and design. (a) MSHA will test only...

  2. 30 CFR 36.20 - Quality of material, workmanship, and design.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Quality of material, workmanship, and design. 36.20 Section 36.20 Mineral...TRANSPORTATION EQUIPMENT Construction and Design Requirements § 36.20 Quality of material, workmanship, and design. (a) MSHA will test only...

  3. Advanced composite structures. [metal matrix composites - structural design criteria for spacecraft construction materials

    NASA Technical Reports Server (NTRS)

    1974-01-01

    A monograph is presented which establishes structural design criteria and recommends practices to ensure the design of sound composite structures, including composite-reinforced metal structures. (It does not discuss design criteria for fiber-glass composites and such advanced composite materials as beryllium wire or sapphire whiskers in a matrix material.) Although the criteria were developed for aircraft applications, they are general enough to be applicable to space vehicles and missiles as well. The monograph covers four broad areas: (1) materials, (2) design, (3) fracture control, and (4) design verification. The materials portion deals with such subjects as material system design, material design levels, and material characterization. The design portion includes panel, shell, and joint design, applied loads, internal loads, design factors, reliability, and maintainability. Fracture control includes such items as stress concentrations, service-life philosophy, and the management plan for control of fracture-related aspects of structural design using composite materials. Design verification discusses ways to prove flightworthiness.

  4. Module Design, Materials, and Packaging Research Team: Activities and Capabilities

    SciTech Connect

    McMahon, T. J.; del Cueto, J.; Glick, S.; Jorgensen, G.; Kempe, M.; Kennedy, C.; Pern, J.; Terwilliger, K

    2005-01-01

    Our team activities are directed at improving PV module reliability by incorporating new, more effective, and less expensive packaging materials and techniques. New and existing materials or designs are evaluated before and during accelerated environmental exposure for the following properties: (1) Adhesion and cohesion: peel strength and lap shear. (2) Electrical conductivity: surface, bulk, interface and transients. (3) Water vapor transmission: solubility and diffusivity. (4) Accelerated weathering: ultraviolet, temperature, and damp heat tests. (5) Module and cell failure diagnostics: infrared imaging, individual cell shunt characterization, coring. (6) Fabrication improvements: SiOxNy barrier coatings and enhanced wet adhesion. (7) Numerical modeling: Moisture ingress/egress, module and cell performance, and cell-to-frame leakage current. (8) Rheological properties of polymer encapsulant and sheeting materials. Specific examples will be described.

  5. Design And Formability Of A New Composite Material

    SciTech Connect

    Bolay, C.; Liewald, M.

    2011-05-04

    Composite materials with metallic cover sheets have been established based on their low weight potential in industrial applications. Further requirements such as high stiffness of component, vibration damping and formability today are only partially met by these composites. For that reason, in current research work, great efforts are being made to develop materials which can be adapted to their later use and load in terms of improving noise, vibration and harshness. Thus, greater stiffness of component structure with a simultaneous reduction of weight can be achieved. This article presents a new composite material which consists of a plane sheet, a thin intermediate damping-layer and a sheet with formed elements to increase stiffness of component such as beads. The plane side can be used as the visible part side. The shape elements increase strength due to work hardening and can be used as design or functional elements. Thus, this composite material results in several advantages within the single layers. Possible flexibility in component design enables new semi-finished or tailored components.

  6. Design and preparation of materials for advanced electrochemical storage.

    PubMed

    Melot, Brent C; Tarascon, J-M

    2013-05-21

    To meet the growing global demand for energy while preserving the environment, it is necessary to drastically reduce the world's dependence on non-renewable energy sources. At the core of this effort will be the ability to efficiently convert, store, transport and access energy in a variety of ways. Batteries for use in small consumer devices have saturated society; however, if they are ever to be useful in large-scale applications such as automotive transportation or grid-storage, they will require new materials with dramatically improved performance. Efforts must also focus on using Earth-abundant and nontoxic compounds so that whatever developments are made will not create new environmental problems. In this Account, we describe a general strategy for the design and development of new insertion electrode materials for Li(Na)-ion batteries that meet these requirements. We begin by reviewing the current state of the art of insertion electrodes and highlighting the intrinsic material properties of electrodes that must be re-engineered for extension to larger-scale applications. We then present a detailed discussion of the relevant criteria for the conceptual design and appropriate selection of new electrode chemical compositions. We describe how the open-circuit voltage of Li-ion batteries can be manipulated and optimized through structural and compositional tuning by exploiting differences in the electronegativity among possible electrode materials. We then discuss which modern synthetic techniques are most sustainable, allowing the creation of new materials via environmentally responsible reactions that minimize the use of energy and toxic solvents. Finally, we present a case study showing how we successfully employed these approaches to develop a large number of new, useful electrode materials within the recently discovered family of transition metal fluorosulfates. This family has attracted interest as a possible source of improved Li-ion batteries in larger scale applications and benefits from a relatively "green" synthesis. PMID:23282038

  7. Chalcogenide Glass Radiation Sensor; Materials Development, Design and Device Testing

    SciTech Connect

    Mitkova, Maria; Butt, Darryl; Kozicki, Michael; Barnaby, Hugo

    2013-04-30

    For many decades, various radiation detecting material have been extensively researched, to find a better material or mechanism for radiation sensing. Recently, there is a growing need for a smaller and effective material or device that can perform similar functions of bulkier Geiger counters and other measurement options, which fail the requirement for easy, cheap and accurate radiation dose measurement. Here arises the use of thin film chalcogenide glass, which has unique properties of high thermal stability along with high sensitivity towards short wavelength radiation. The unique properties of chalcogenide glasses are attributed to the lone pair p-shell electrons, which provide some distinctive optical properties when compared to crystalline material. These qualities are derived from the energy band diagram and the presence of localized states in the band gap. Chalcogenide glasses have band tail states and localized states, along with the two band states. These extra states are primarily due to the lone pair electrons as well as the amorphous structure of the glasses. The localized states between the conductance band (CB) and valence band (VB) are primarily due to the presence of the lone pair electrons, while the band tail states are attributed to the Van der Waalâ??s forces between layers of atoms [1]. Localized states are trap locations within the band gap where electrons from the valence band can hop into, in their path towards the conduction band. Tail states on the other hand are locations near the band gap edges and are known as Urbach tail states (Eu). These states are occupied with many electrons that can participate in the various transformations due to interaction with photons. According to Y. Utsugi et. al.[2], the electron-phonon interactions are responsible for the generation of the Urbach tails. These states are responsible for setting the absorption edge for these glasses and photons with energy near the band gap affect these states. We have studied the effect of x-rays and γ-rays, on thin film chalcogenide glasses and applied them in conjunction with film incorporating a silver source in a new type of radiation sensor for which we have an US patent application [3]. In this report, we give data about our studies regarding our designed radiation sensor along with the testing and performance at various radiation doses. These studies have been preceded by materials characterization research related to the compositional and structural characteristics of the active materials used in the radiation sensor design. During the work on the project, we collected a large volume of material since every experiment was repeated many times to verify the results. We conducted a comprehensive material research, analysis and discussion with the aim to understand the nature of the occurring effects, design different structures to harness these effects, generated models to aid in the understanding the effects, built different device structures and collected data to quantify device performance. These various aspects of our investigation have been detailed in previous quarterly reports. In this report, we present our main results and emphasize on the results pertaining to the core project goals â?? materials development, sensor design and testing and with an emphasis on classifying the appropriate material and design for the optimal application. The report has three main parts: (i) Presentation of the main data; (ii) Bulleted summary of the most important results; (iii) List of the patent, journal publications, conference proceedings and conferences participation, occurring as a result of working on the project.

  8. Designs and Materials for Better Coronagraph Occulting Masks

    NASA Technical Reports Server (NTRS)

    Balasubramanian, Kunjithapatham

    2010-01-01

    New designs, and materials appropriate for such designs, are under investigation in an effort to develop coronagraph occulting masks having broad-band spectral characteristics superior to those currently employed. These designs and materials are applicable to all coronagraphs, both ground-based and spaceborne. This effort also offers potential benefits for the development of other optical masks and filters that are required (1) for precisely tailored spatial transmission profiles, (2) to be characterized by optical-density neutrality and phase neutrality (that is, to be characterized by constant optical density and constant phase over broad wavelength ranges), and/or (3) not to exhibit optical- density-dependent phase shifts. The need for this effort arises for the following reasons: Coronagraph occulting masks are required to impose, on beams of light transmitted through them, extremely precise control of amplitude and phase according to carefully designed transmission profiles. In the original application that gave rise to this effort, the concern has been to develop broad-band occulting masks for NASA s Terrestrial Planet Finder coronagraph. Until now, experimental samples of these masks have been made from high-energy-beam-sensitive (HEBS) glass, which becomes locally dark where irradiated with a high-energy electron beam, the amount of darkening depending on the electron-beam energy and dose. Precise mask profiles have been written on HEBS glass blanks by use of electron beams, and the masks have performed satisfactorily in monochromatic light. However, the optical-density and phase profiles of the HEBS masks vary significantly with wavelength; consequently, the HEBS masks perform unsatisfactorily in broad-band light. The key properties of materials to be used in coronagraph occulting masks are their extinction coefficients, their indices of refraction, and the variations of these parameters with wavelength. The effort thus far has included theoretical predictions of performances of masks that would be made from alternative materials chosen because the wavelength dependences of their extinction coefficients and their indices of refraction are such that that the optical-density and phase profiles of masks made from these materials can be expected to vary much less with wavelength than do those of masks made from HEBS glass. The alternative materials considered thus far include some elemental metals such as Pt and Ni, metal alloys such as Inconel, metal nitrides such as TiN, and dielectrics such as SiO2. A mask as now envisioned would include thin metal and dielectric films having stepped or smoothly varying thicknesses (see figure). The thicknesses would be chosen, taking account of the indices of refraction and extinction coefficients, to obtain an acceptably close approximation of the desired spatial transmittance profile with a flat phase profile

  9. Design Molecular Recognition Materials for Chiral Sensors, Separtations and Catalytic Materials

    SciTech Connect

    Jia, S.; Nenoff, T.M.; Provencio, P.; Qiu, Y.; Shelnutt, J.A.; Thoma, S.G.; Zhang, J.

    1998-11-01

    The goal is the development of materials that are highly sensitive and selective for chid chemicals and biochemical (such as insecticides, herbicides, proteins, and nerve agents) to be used as sensors, catalysts and separations membranes. Molecular modeling methods are being used to tailor chiral molecular recognition sites with high affinity and selectivity for specified agents. The work focuses on both silicate and non-silicate materials modified with chirally-pure fictional groups for the catalysis or separations of enantiomerically-pure molecules. Surfactant and quaternary amine templating is being used to synthesize porous frameworks, containing mesopores of 30 to 100 angstroms. Computer molecukw modeling methods are being used in the design of these materials, especially in the chid surface- modi~ing agents. Molecular modeling is also being used to predict the catalytic and separations selectivities of the modified mesoporous materials. The ability to design and synthesize tailored asymmetric molecular recognition sites for sensor coatings allows a broader range of chemicals to be sensed with the desired high sensitivity and selectivity. Initial experiments target the selective sensing of small molecule gases and non-toxic model neural compounds. Further efforts will address designing sensors that greatly extend the variety of resolvable chemical species and forming a predictive, model-based method for developing advanced sensors.

  10. Materials, design and processing of air encapsulated MEMS packaging

    NASA Astrophysics Data System (ADS)

    Fritz, Nathan T.

    This work uses a three-dimensional air cavity technology to improve the fabrication, and functionality of microelectronics devices, performance of on-board transmission lines, and packaging of micro-electromechanical systems (MEMS). The air cavity process makes use of the decomposition of a patterned sacrificial polymer followed by the diffusion of its by-products through a curing polymer overcoat to obtain the embedded air structure. Applications and research of air cavities have focused on simple designs that concentrate on the size and functionality of the particular device. However, a lack of guidelines for fabrication, materials used, and structural design has led to mechanical stability issues and processing refinements. This work investigates improved air gap cavities for use in MEMS packaging processes, resulting in fewer fabrication flaws and lower cost. The identification of new materials, such as novel photo-definable organic/inorganic hybrid polymers, was studied for increased strength and rigidity due to their glass-like structure. A novel epoxy polyhedral oligomeric silsesquioxane (POSS) material was investigated and characterized for use as a photodefineable, permanent dielectrics with improved mechanical properties. The POSS material improved the air gap fabrication because it served as a high-selectivity etch mask for patterning sacrificial materials as well as a cavity overcoat material with improved rigidity. An investigation of overcoat thickness and decomposition kinetics provided a fundamental understanding of the properties that impart mechanical stability to cavities of different shape and volume. Metallization of the cavities was investigated so as to provide hermetic sealing and improved cavity strength. The improved air cavity, wafer-level packages were tested using resonator-type devices and chip-level lead frame packaging. The air cavity package was molded under traditional lead frame molding pressures and tested for mechanical integrity. The development of mechanical models complimented the experimental studies. A model of the overcoat materials used the film properties and elastic deformations to study the stress-strain behavior of the suspended dielectric films under external forces. The experimental molding tests and mechanical models were used to establish processing conditions and physical designs for the cavities as a function of cavity size. A novel, metal-free chip package was investigated combining the in-situ thermal decomposition of the sacrificial material during post-mold curing of the lead frame molding compound. Sacrificial materials were characterized for their degree of decomposition during the molding cure to provide a chip package with improved mechanical support and no size restrictions. Improvements to the air cavities for MEMS packaging led to investigations and refinements of other microfabrication processes. The sacrificial polycarbonate materials were shown to be useful as temporary bonding materials for wafer-level bonding. The release temperature and conditions of the processed wafer can be changed based on the polycarbonates formulation. The electroless deposition of metal was investigated as an alternative process for metalizing the air cavities. The deposition of silver and copper using a Sn/Ag catalyst as a replacement for costly palladium activation was demonstrated. The electroless deposition was tested on polymer and silicon dioxide surfaces for organic boards and through-silicon vias.

  11. System design for safe robotic handling of nuclear materials

    SciTech Connect

    Drotning, W.; Wapman, W.; Fahrenholtz, J.; Kimberly, H.; Kuhlmann, J.

    1996-03-01

    Robotic systems are being developed by the Intelligent Systems and Robotics Center at Sandia National Laboratories to perform automated handling tasks with radioactive nuclear materials. These systems will reduce the occupational radiation exposure to workers by automating operations which are currently performed manually. Because the robotic systems will handle material that is both hazardous and valuable, the safety of the operations is of utmost importance; assurance must be given that personnel will not be harmed and that the materials and environment will be protected. These safety requirements are met by designing safety features into the system using a layered approach. Several levels of mechanical, electrical and software safety prevent unsafe conditions from generating a hazard, and bring the system to a safe state should an unexpected situation arise. The system safety features include the use of industrial robot standards, commercial robot systems, commercial and custom tooling, mechanical safety interlocks, advanced sensor systems, control and configuration checks, and redundant control schemes. The effectiveness of the safety features in satisfying the safety requirements is verified using a Failure Modes and Effects Analysis. This technique can point out areas of weakness in the safety design as well as areas where unnecessary redundancy may reduce the system reliability.

  12. A model for designing functionally gradient material joints

    SciTech Connect

    Jou, M.; Messler, R.W.; Orling, T.T.

    1994-12-31

    Joining of dissimilar materials into hybrid structures to meet severe design and service requirements is becoming more necessary and common. Joints between heat-resisting or refractory metals and refractory or corrosion resistant ceramics and intermetallics are especially in demand. Before resorting to a more complicated but versatile finite element analysis (FEA) model, a simpler, more user-friendly analytical layer-model based on a thin plate assumption was developed and tested. The model has been successfully used to design simple FGM joints between Ni-base superalloys or Mo and SiC, Ni{sub 3}Al or Al{sub 2}O{sub 3} using self-propagating high-temperature or pressurized composition synthesis for joining. Cases are presented to demonstrate capability for: (1) varying processing temperature excursions or service gradients; (2) varying overall joint thickness for a fixed number of uniform composition steps; (3) varying the number of uniform steps for a particular overall joint thickness; (4) varying the thickness and/or composition of individual steps for a constant overall thickness; and (5) altering the constitutive law for mixed-material composition steps. The model provides a useful joint design tool for process R&D.

  13. Test model designs for advanced refractory ceramic materials

    NASA Technical Reports Server (NTRS)

    Tran, Huy Kim

    1993-01-01

    The next generation of space vehicles will be subjected to severe aerothermal loads and will require an improved thermal protection system (TPS) and other advanced vehicle components. In order to ensure the satisfactory performance system (TPS) and other advanced vehicle materials and components, testing is to be performed in environments similar to space flight. The design and fabrication of the test models should be fairly simple but still accomplish test objectives. In the Advanced Refractory Ceramic Materials test series, the models and model holders will need to withstand the required heat fluxes of 340 to 817 W/sq cm or surface temperatures in the range of 2700 K to 3000 K. The model holders should provide one dimensional (1-D) heat transfer to the samples and the appropriate flow field without compromising the primary test objectives. The optical properties such as the effective emissivity, catalytic efficiency coefficients, thermal properties, and mass loss measurements are also taken into consideration in the design process. Therefore, it is the intent of this paper to demonstrate the design schemes for different models and model holders that would accommodate these test requirements and ensure the safe operation in a typical arc jet facility.

  14. Testing and design life analysis of polyurea liner materials

    NASA Astrophysics Data System (ADS)

    Ghasemi Motlagh, Siavash

    Certainly, water pipes, as part of an underground infrastructure system, play a key role in maintaining quality of life, health, and wellbeing of human kind. As these potable water pipes reach the end of their useful life, they create high maintenance costs, loss of flow capacity, decreased water quality, and increased dissatisfaction. There are several different pipeline renewal techniques available for different applications, among which linings are most commonly used for the renewal of water pipes. Polyurea is a lining material applied to the interior surface of the deteriorated host pipe using spray-on technique. It is applied to structurally enhance the host pipe and provide a barrier coating against further corrosion or deterioration. The purpose of this study was to establish a relationship between stress, strain and time. The results obtained from these tests were used in predicting the strength of the polyurea material during its planned 50-year design life. In addition to this, based on the 10,000 hours experimental data, curve fitting and Findley power law models were employed to predict long-term behavior of the material. Experimental results indicated that the tested polyurea material offers a good balance of strength and stiffness and can be utilized in structural enhancement applications of potable water pipes.

  15. Designing thin film materials — Ternary borides from first principles

    PubMed Central

    Euchner, H.; Mayrhofer, P.H.

    2015-01-01

    Exploiting the mechanisms responsible for the exceptional properties of aluminum based nitride coatings, we apply ab initio calculations to develop a recipe for designing functional thin film materials based on ternary diborides. The combination of binary diborides, preferring different structure types, results in supersaturated metastable ternary systems with potential for phase transformation induced effects. For the exemplary cases of MxW1 ? xB2 (with M = Al, Ti, V) we show by detailed ab initio calculations that the respective ternary solid solutions are likely to be experimentally accessible by modern depositions techniques. PMID:26082562

  16. Design of materials configurations for enhanced phononic and electronic properties

    NASA Astrophysics Data System (ADS)

    Daraio, Chiara

    The discovery of novel nonlinear dynamic and electronic phenomena is presented for the specific cases of granular materials and carbon nanotubes. This research was conducted for designing and constructing optimized macro-, micro- and nano-scale structural configurations of materials, and for studying their phononic and electronic behavior. Variation of composite arrangements of granular elements with different elastic properties in a linear chain-of-sphere, Y-junction or 3-D configurations led to a variety of novel phononic phenomena and interesting physical properties, which can be potentially useful for security, communications, mechanical and biomedical engineering applications. Mechanical and electronic properties of carbon nanotubes with different atomic arrangements and microstructures were also investigated. Electronic properties of Y-junction configured carbon nanotubes exhibit an exciting transistor switch behavior which is not seen in linear configuration nanotubes. Strongly nonlinear materials were designed and fabricated using novel and innovative concepts. Due to their unique strongly nonlinear and anisotropic nature, novel wave phenomena have been discovered. Specifically, violations of Snell's law were detected and a new mechanism of wave interaction with interfaces between NTPCs (Nonlinear Tunable Phononic Crystals) was established. Polymer-based systems were tested for the first time, and the tunability of the solitary waves speed was demonstrated. New materials with transformed signal propagation speed in the manageable range of 10-100 m/s and signal amplitude typical for audible speech have been developed. The enhancing of the mitigation of solitary and shock waves in 1-D chains were demonstrated and a new protective medium was designed for practical applications. 1-D, 2-D and 3-D strongly nonlinear system have been investigated providing a broad impact on the whole area of strongly nonlinear wave dynamics and creating experimental basis for new theories and models. Potential applications include (1) designing of a sound scrambler/decoder for secure voice communications, (2) improving invisibility of submarine to acoustic detection signal, (3) noise and shock wave mitigation for protection of vibration sensitive devices such as head mounted vision devices, (4) drastic compression of acoustic signals into centimeter regime impulses for artificial ear implants, hearing aid and devices for ease of conversion to electronic signals and processing, and acoustic delay lines for communication applications.

  17. Hybrid materials science: a promised land for the integrative design of multifunctional materials

    NASA Astrophysics Data System (ADS)

    Nicole, Lionel; Laberty-Robert, Christel; Rozes, Laurence; Sanchez, Clément

    2014-05-01

    For more than 5000 years, organic-inorganic composite materials created by men via skill and serendipity have been part of human culture and customs. The concept of ``hybrid organic-inorganic'' nanocomposites exploded in the second half of the 20th century with the expansion of the so-called ``chimie douce'' which led to many collaborations between a large set of chemists, physicists and biologists. Consequently, the scientific melting pot of these very different scientific communities created a new pluridisciplinary school of thought. Today, the tremendous effort of basic research performed in the last twenty years allows tailor-made multifunctional hybrid materials with perfect control over composition, structure and shape. Some of these hybrid materials have already entered the industrial market. Many tailor-made multiscale hybrids are increasingly impacting numerous fields of applications: optics, catalysis, energy, environment, nanomedicine, etc. In the present feature article, we emphasize several fundamental and applied aspects of the hybrid materials field: bioreplication, mesostructured thin films, Lego-like chemistry designed hybrid nanocomposites, and advanced hybrid materials for energy. Finally, a few commercial applications of hybrid materials will be presented.

  18. ATRP in the design of functional materials for biomedical applications

    PubMed Central

    Siegwart, Daniel J.; Oh, Jung Kwon; Matyjaszewski, Krzysztof

    2013-01-01

    Atom Transfer Radical Polymerization (ATRP) is an effective technique for the design and preparation of multifunctional, nanostructured materials for a variety of applications in biology and medicine. ATRP enables precise control over macromolecular structure, order, and functionality, which are important considerations for emerging biomedical designs. This article reviews recent advances in the preparation of polymer-based nanomaterials using ATRP, including polymer bioconjugates, block copolymer-based drug delivery systems, cross-linked microgels/nanogels, diagnostic and imaging platforms, tissue engineering hydrogels, and degradable polymers. It is envisioned that precise engineering at the molecular level will translate to tailored macroscopic physical properties, thus enabling control of the key elements for realized biomedical applications. PMID:23525884

  19. Taguchi method of experimental design in materials education

    NASA Technical Reports Server (NTRS)

    Weiser, Martin W.

    1993-01-01

    Some of the advantages and disadvantages of the Taguchi Method of experimental design as applied to Materials Science will be discussed. This is a fractional factorial method that employs the minimum number of experimental trials for the information obtained. The analysis is also very simple to use and teach, which is quite advantageous in the classroom. In addition, the Taguchi loss function can be easily incorporated to emphasize that improvements in reproducibility are often at least as important as optimization of the response. The disadvantages of the Taguchi Method include the fact that factor interactions are normally not accounted for, there are zero degrees of freedom if all of the possible factors are used, and randomization is normally not used to prevent environmental biasing. In spite of these disadvantages it is felt that the Taguchi Method is extremely useful for both teaching experimental design and as a research tool, as will be shown with a number of brief examples.

  20. Advances in design and modeling of porous materials

    NASA Astrophysics Data System (ADS)

    Ayral, André; Calas-Etienne, Sylvie; Coasne, Benoit; Deratani, André; Evstratov, Alexis; Galarneau, Anne; Grande, Daniel; Hureau, Matthieu; Jobic, Hervé; Morlay, Catherine; Parmentier, Julien; Prelot, Bénédicte; Rossignol, Sylvie; Simon-Masseron, Angélique; Thibault-Starzyk, Frédéric

    2015-07-01

    This special issue of the European Physical Journal Special Topics is dedicated to selected papers from the symposium "High surface area porous and granular materials" organized in the frame of the conference "Matériaux 2014", held on November 24-28, 2014 in Montpellier, France. Porous materials and granular materials gather a wide variety of heterogeneous, isotropic or anisotropic media made of inorganic, organic or hybrid solid skeletons, with open or closed porosity, and pore sizes ranging from the centimeter scale to the sub-nanometer scale. Their technological and industrial applications cover numerous areas from building and civil engineering to microelectronics, including also metallurgy, chemistry, health, waste water and gas effluent treatment. Many emerging processes related to environmental protection and sustainable development also rely on this class of materials. Their functional properties are related to specific transfer mechanisms (matter, heat, radiation, electrical charge), to pore surface chemistry (exchange, adsorption, heterogeneous catalysis) and to retention inside confined volumes (storage, separation, exchange, controlled release). The development of innovative synthesis, shaping, characterization and modeling approaches enables the design of advanced materials with enhanced functional performance. The papers collected in this special issue offer a good overview of the state-of-the-art and science of these complex media. We would like to thank all the speakers and participants for their contribution to the success of the symposium. We also express our gratitude to the organization committee of "Matériaux 2014". We finally thank the reviewers and the staff of the European Physical Journal Special Topics who made the publication of this special issue possible.

  1. Failure modes and materials design for biomechanical layer structures

    NASA Astrophysics Data System (ADS)

    Deng, Yan

    Ceramic materials are finding increasing usage in the area of biomechanical replacements---dental crowns, hip and bone implants, etc.---where strength, wear resistance, biocompatibility, chemical durability and even aesthetics are critical issues. Aesthetic ceramic crowns have been widely used in dentistry to replace damaged or missing teeth. However, the failure rates of ceramic crowns, especially all-ceramic crowns, can be 1%˜6% per year, which is not satisfactory to patients. The materials limitations and underlying fracture mechanisms of these prostheses are not well understood. In this thesis, fundamental fracture and damage mechanisms in model dental bilayer and trilayer structures are studied. Principle failure modes are identified from in situ experimentation and confirmed by fracture mechanics analysis. In bilayer structures of ceramic/polycarbonate (representative of ceramic crown/dentin structure), three major damage sources are identified: (i) top-surface cone cracks or (ii) quasiplasticity, dominating in thick ceramic bilayers; (iii) bottom-surface radial cracks, dominating in thin ceramic bilayers. Critical load P for each damage mode are measured in six dental ceramics: Y-TZP zirconia, glass-infiltrated zirconia and alumina (InCeram), glass-ceramic (Empress II), Porcelain (Mark II and Empress) bonded to polymer substrates, as a function of ceramic thickness d in the range of 100 mum to 10 mm. P is found independent of d for mode (i) and (ii), but has a d 2 relations for mode (iii)---bottom surface radial cracking. In trilayer structures of glass/core-ceramic/polycarbonate (representing veneer porcelain/core/dentin structures), three inner fracture origins are identified: radial cracks from the bottom surface in the (i) first and (ii) second layers; and (iii) quasiplasticity in core-ceramic layer. The role of relative veneer/core thickness, d1/d 2 and materials properties is investigated for three core materials with different modulus (114--270GPa) and strength (400--1400MPa): Y-TZP zirconia, InCeram alumina and Empress II glass-ceramic. Explicit relations for the critical loads P to produce these different damage modes in bilayer and trilayer structures are developed in terms of basic material properties (modulus E, strength, hardness H and toughness T) and geometrical variables (thickness d and contact sphere radius r). These experimentally validated relations are used to design of optimal material combinations for improved fracture resistance and to predict mechanical performance of current dental materials.

  2. Harvesting bioenergy with rationally designed complex functional materials

    NASA Astrophysics Data System (ADS)

    Kuang, Liangju

    A key challenge in renewable energy is to capture, convert and store solar power with earth-abundant materials and environmentally benign technologies. The goal of this thesis is to develop rationally designed complex functional materials for bio-renewable energy applications. On one hand, photoconversion membrane proteins (MPs) are nature's nanoengineering feats for renewable energy management. Harnessing their functions in synthetic systems could help understand, predict, and ultimately control matter and energy at the nanoscale. This is particularly enticing in the post-genome era as recombinant or cell-free expression of many MPs with high yields becomes possible. However, the labile nature of lipid bilayers renders them unsuitable for use in a broad range of engineered systems. A knowledge gap exists about how to design robust synthetic nanomembranes as lipid-bilayer-mimics to support MP functions and how to direct hierarchical MP reconstitution into those membranes to form 2-D or 3-D ordered proteomembrane arrays. Our studies on proteorhodopsin (PR) and bacterial reaction center (BRC), the two light-harvesting MPs, reveal that a charge-interaction-directed reconstitution (CIDR) mechanism induces spontaneous reconstitution of detergent-solubilized MPs into various amphiphilic block copolymer membranes, many of which have far superior stability than lipid bilayers. Our preliminary data also suggest MPs are not enslaved by the biological membranes they derive from; rather, the chemically nonspecific material properties of MP-supporting membranes may act as allosteric regulators. Versatile chemical designs are possible to modulate the conformational energetics of MPs, hence their transport performance in synthetic systems. On the other hand, microalgae are widely regarded as a sustainable feedstock for biofuel production. Microalgae-derived biofuels have not been commercialized yet because current technologies for microalgae dewatering add a huge cost to the final product, and present a major bottleneck. We propose to solve the microalgae dewatering problem in the context of controlling colloidal stability, where inter-algal potential is tuned via surface engineering of novel coagulation agents. We report here a nanoparticle-pinched polymer brush design that combines two known colloidal destabilization agents (e.g., nanoparticle and polymer) into one system, and allows the use of an external field (e.g., magnetic force) to not only modulate inter-algae pair potentials, but also facilitate retrieval of the coagulation agents to be reused after algal oil extraction. We will discuss our extensive data on the preparation of well-defined nanoparticle-pinched polymer brushes, their structure-dependent coagulation performance on both fresh water and marine microalgae species, and their re-suability for continuous cycles of microalgae farming and harvesting.

  3. Optimal Design of Honeycomb Material Used to Mitigate Head Impact

    PubMed Central

    Caccese, Vincent; Ferguson, James R.; Edgecomb, Michael

    2013-01-01

    This paper presents a study of the impact resistance of honeycomb structure with the purpose to mitigate impact forces. The objective is to aid in the choice of optimal parameters to minimize the thickness of the honeycomb structure while providing adequate protection to prevent injury due to head impact. Studies are presented using explicit finite element analysis representing the case of an unprotected drop of a rigid impactor onto a simulated floor consisting of vinyl composition tile and concrete. Analysis of honeycomb material to reduce resulting accelerations is also presented where parameters such as honeycomb material modulus, wall thickness, cell geometry and structure depth are compared to the unprotected case. A simplified analysis technique using a genetic algorithm is presented to demonstrate the use of this method to select a minimum honeycomb depth to achieve a desired acceleration level at a given level of input energy. It is important to select a minimum material depth in that smaller dimensions lead toward more aesthetic design that increase the likelihood of that the device is used. PMID:23976812

  4. Materials for Consideration in Standardized Canister Design Activities.

    SciTech Connect

    Bryan, Charles R.; Ilgen, Anastasia Gennadyevna; Enos, David George; Teich-McGoldrick, Stephanie; Hardin, Ernest

    2014-10-02

    This document identifies materials and material mitigation processes that might be used in new designs for standardized canisters for storage, transportation, and disposal of spent nuclear fuel. It also addresses potential corrosion issues with existing dual-purpose canisters (DPCs) that could be addressed in new canister designs. The major potential corrosion risk during storage is stress corrosion cracking of the weld regions on the 304 SS/316 SS canister shell due to deliquescence of chloride salts on the surface. Two approaches are proposed to alleviate this potential risk. First, the existing canister materials (304 and 316 SS) could be used, but the welds mitigated to relieve residual stresses and/or sensitization. Alternatively, more corrosion-resistant steels such as super-austenitic or duplex stainless steels, could be used. Experimental testing is needed to verify that these alternatives would successfully reduce the risk of stress corrosion cracking during fuel storage. For disposal in a geologic repository, the canister will be enclosed in a corrosion-resistant or corrosion-allowance overpack that will provide barrier capability and mechanical strength. The canister shell will no longer have a barrier function and its containment integrity can be ignored. The basket and neutron absorbers within the canister have the important role of limiting the possibility of post-closure criticality. The time period for corrosion is much longer in the post-closure period, and one major unanswered question is whether the basket materials will corrode slowly enough to maintain structural integrity for at least 10,000 years. Whereas there is extensive literature on stainless steels, this evaluation recommends testing of 304 and 316 SS, and more corrosion-resistant steels such as super-austenitic, duplex, and super-duplex stainless steels, at repository-relevant physical and chemical conditions. Both general and localized corrosion testing methods would be used to establish corrosion rates and component lifetimes. Finally, it is unlikely that the aluminum-based neutron absorber materials that are commonly used in existing DPCs would survive for 10,000 years in disposal environments, because the aluminum will act as a sacrificial anode for the steel. We recommend additional testing of borated and Gd-bearing stainless steels, to establish general and localized corrosion resistance in repository-relevant environmental conditions.

  5. Molding and filament winding of spatially graded material properties through computational design

    E-print Network

    Gonzalez Uribe, Carlos David

    2014-01-01

    Three-dimensional printing and computational design have enabled designers to spatially vary material properties in objects. Nevertheless, this technology has current limitations that include material durability, cost and ...

  6. Design of semi-active variable impedance materials using field-responsive fluids

    E-print Network

    Eastman, Douglas Elmer

    2004-01-01

    In this thesis, I explored the design of a thin variable impedance material using electrorheological (ER) fluid that is intended to be worn by humans. To determine the critical design parameters of this material, the shear ...

  7. Microstructure-Property Relation and Evolution for the Design of Advanced Hierarchical Materials Cohesive law

    E-print Network

    Chen, Wei

    n Fiber Cohesive law Viscoplastic behavior Enable material design based on the microstructure conformation and properties. Two materials were evaluated: composites and metal alloys RESEARCH OBJECTIVE Polymer Matrix Composites: Design made possible through performance prediction for different mechanical

  8. EXPERIMENTAL STUDIES ON PARTICLE IMPACTION AND BOUNCE: EFFECTS OF SUBSTRATE DESIGN AND MATERIAL. (R825270)

    EPA Science Inventory

    This paper presents an experimental investigation of the effects of impaction substrate designs and material in reducing particle bounce and reentrainment. Particle collection without coating by using combinations of different impaction substrate designs and surface materials was...

  9. Process design of press hardening with gradient material property influence

    SciTech Connect

    Neugebauer, R.; Schieck, F.; Rautenstrauch, A.

    2011-05-04

    Press hardening is currently used in the production of automotive structures that require very high strength and controlled deformation during crash tests. Press hardening can achieve significant reductions of sheet thickness at constant strength and is therefore a promising technology for the production of lightweight and energy-efficient automobiles. The manganese-boron steel 22MnB5 have been implemented in sheet press hardening owing to their excellent hot formability, high hardenability, and good temperability even at low cooling rates. However, press-hardened components have shown poor ductility and cracking at relatively small strains. A possible solution to this problem is a selective increase of steel sheet ductility by press hardening process design in areas where the component is required to deform plastically during crash tests. To this end, process designers require information about microstructure and mechanical properties as a function of the wide spectrum of cooling rates and sequences and austenitizing treatment conditions that can be encountered in production environments. In the present work, a Continuous Cooling Transformation (CCT) diagram with corresponding material properties of sheet steel 22MnB5 was determined for a wide spectrum of cooling rates. Heating and cooling programs were conducted in a quenching dilatometer. Motivated by the importance of residual elasticity in crash test performance, this property was measured using a micro-bending test and the results were integrated into the CCT diagrams to complement the hardness testing results. This information is essential for the process design of press hardening of sheet components with gradient material properties.

  10. 46 CFR 160.076-17 - Approval of design or material changes.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Approval of design or material changes. 160.076-17... Flotation Devices § 160.076-17 Approval of design or material changes. (a) The manufacturer must submit any proposed changes in design, material, or construction to the recognized laboratory and the Commandant...

  11. A domain-specific design architecture for composite material design and aircraft part redesign

    NASA Technical Reports Server (NTRS)

    Punch, W. F., III; Keller, K. J.; Bond, W.; Sticklen, J.

    1992-01-01

    Advanced composites have been targeted as a 'leapfrog' technology that would provide a unique global competitive position for U.S. industry. Composites are unique in the requirements for an integrated approach to designing, manufacturing, and marketing of products developed utilizing the new materials of construction. Numerous studies extending across the entire economic spectrum of the United States from aerospace to military to durable goods have identified composites as a 'key' technology. In general there have been two approaches to composite construction: build models of a given composite materials, then determine characteristics of the material via numerical simulation and empirical testing; and experience-directed construction of fabrication plans for building composites with given properties. The first route sets a goal to capture basic understanding of a device (the composite) by use of a rigorous mathematical model; the second attempts to capture the expertise about the process of fabricating a composite (to date) at a surface level typically expressed in a rule based system. From an AI perspective, these two research lines are attacking distinctly different problems, and both tracks have current limitations. The mathematical modeling approach has yielded a wealth of data but a large number of simplifying assumptions are needed to make numerical simulation tractable. Likewise, although surface level expertise about how to build a particular composite may yield important results, recent trends in the KBS area are towards augmenting surface level problem solving with deeper level knowledge. Many of the relative advantages of composites, e.g., the strength:weight ratio, is most prominent when the entire component is designed as a unitary piece. The bottleneck in undertaking such unitary design lies in the difficulty of the re-design task. Designing the fabrication protocols for a complex-shaped, thick section composite are currently very difficult. It is in fact this difficulty that our research will address.

  12. Design and synthesis of novel resist materials for EUVL

    NASA Astrophysics Data System (ADS)

    Satyanarayana, V. S. V.; Singh, Vikram; Ghosh, Subrata; Sharma, Satinder; Gonsalves, Kenneth E.

    2014-04-01

    The design, synthesis and characterization of non-chemically amplified negative tone electron-beam and EUV resists based on the inclusion of a radiation sensitive sulfonium functional group are outlined.. MAPDST (4-(methacryloyloxy phenyldimethylsulfoniumtriflate) and MANTMS (1-(4-(methacryloyloxy)naphthalen-1-yl)tetrahydro-1H thiopheniumtrifluoromethane sulfonate) monomers each containing the sulfonium group underwent homo- and copolymerizations using free radical polymerization with 2,2'-azobisisobutyronitrile (AIBN) initiator. These resist materials were evaluated by EB lithography using 20 keV electron beam and EUV lithography to obtain sub-20 nm line patterns. These features were optimized ranging from resist coating, pre-exposure bake, exposure to e-beam, postexposure bake, development and imaging. Our investigation showed that these newly synthesized resists are potential viable candidates for EUV lithography based on their ability to form flaw free thin films < 50nm, sensitivity, resolution and LER control.

  13. Conceptual design report: Nuclear materials storage facility renovation. Part 1, Design concept. Part 2, Project management

    SciTech Connect

    1995-07-14

    The Nuclear Materials Storage Facility (NMSF) at the Los Alamos National Laboratory (LANL) was a Fiscal Year (FY) 1984 line-item project completed in 1987 that has never been operated because of major design and construction deficiencies. This renovation project, which will correct those deficiencies and allow operation of the facility, is proposed as an FY 97 line item. The mission of the project is to provide centralized intermediate and long-term storage of special nuclear materials (SNM) associated with defined LANL programmatic missions and to establish a centralized SNM shipping and receiving location for Technical Area (TA)-55 at LANL. Based on current projections, existing storage space for SNM at other locations at LANL will be loaded to capacity by approximately 2002. This will adversely affect LANUs ability to meet its mission requirements in the future. The affected missions include LANL`s weapons research, development, and testing (WRD&T) program; special materials recovery; stockpile survelliance/evaluation; advanced fuels and heat sources development and production; and safe, secure storage of existing nuclear materials inventories. The problem is further exacerbated by LANL`s inability to ship any materials offsite because of the lack of receiver sites for mate rial and regulatory issues. Correction of the current deficiencies and enhancement of the facility will provide centralized storage close to a nuclear materials processing facility. The project will enable long-term, cost-effective storage in a secure environment with reduced radiation exposure to workers, and eliminate potential exposures to the public. This document provides Part I - Design Concept which describes the selected solution, and Part II - Project Management which describes the management system organization, the elements that make up the system, and the control and reporting system.

  14. 30 CFR 18.20 - Quality of material, workmanship, and design.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Quality of material, workmanship, and design... Construction and Design Requirements § 18.20 Quality of material, workmanship, and design. (a) Electrically... right to modify design, construction, and test requirements to obtain the same degree of protection...

  15. 30 CFR 18.20 - Quality of material, workmanship, and design.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Quality of material, workmanship, and design... Construction and Design Requirements § 18.20 Quality of material, workmanship, and design. (a) Electrically... right to modify design, construction, and test requirements to obtain the same degree of protection...

  16. 30 CFR 18.20 - Quality of material, workmanship, and design.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Quality of material, workmanship, and design... Construction and Design Requirements § 18.20 Quality of material, workmanship, and design. (a) Electrically... right to modify design, construction, and test requirements to obtain the same degree of protection...

  17. 30 CFR 18.20 - Quality of material, workmanship, and design.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Quality of material, workmanship, and design... Construction and Design Requirements § 18.20 Quality of material, workmanship, and design. (a) Electrically... right to modify design, construction, and test requirements to obtain the same degree of protection...

  18. 30 CFR 18.20 - Quality of material, workmanship, and design.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Quality of material, workmanship, and design... Construction and Design Requirements § 18.20 Quality of material, workmanship, and design. (a) Electrically... right to modify design, construction, and test requirements to obtain the same degree of protection...

  19. Mechanical design of mussel byssus: material yield enhances attachment strength

    PubMed

    Bell; Gosline

    1996-01-01

    The competitive dominance of mussels in the wave-swept rocky intertidal zone is in part due to their ability to maintain a secure attachment. Mussels are tethered to the substratum by a byssus composed of numerous extracellular, collagenous threads secreted by the foot. Each byssal thread has three serially arranged parts: a corrugated proximal region, a smooth distal region and an adhesive plaque. This study examines the material and structural properties of the byssal threads of three mussel species: Mytilus californianus, M. trossulus, and M. galloprovincialis. Tensile tests in general reveal similar material properties among species: the proximal region has a lower initial modulus, a lower ultimate stress and a higher ultimate strain than the distal region. The distal region also yields at a stress well below its ultimate value. In whole thread tests, the proximal region and adhesive plaque are common sites of structural failure and are closely matched in strength, while the distal region appears to be excessively strong. We propose that the high strength of the distal region is the byproduct of a material designed to yield and extend before structural failure occurs. Experimental and theoretical evidence is presented suggesting that thread yield and extensibility provide two important mechanisms for increasing the overall attachment strength of the mussel: (1) the reorientation of threads towards the direction of applied load, and (2) the 'recruitment' of more threads into tension and the consequent distribution of applied load over a larger cross-sectional area, thereby reducing the stress on each thread. This distal region yield behavior is most striking for M. californianus and may be a key to its success in extreme wave-swept environments. PMID:9318809

  20. Proceedings of the 2000 International Material Handling Research Colloquium RETHINKING WAREHOUSE DESIGN RESEARCH

    E-print Network

    Proceedings of the 2000 International Material Handling Research Colloquium RETHINKING WAREHOUSE of integrated computational tools to support warehouse design and optimization, and warehousing-related courses. Recent collaboration with expert warehouse designers has caused a rethinking of the warehouse design

  1. Microstructure sensitive design: A tool for exploiting material anisotropy in mechanical design

    NASA Astrophysics Data System (ADS)

    Houskamp, Joshua Robert

    A new mathematical framework called Microstructure Sensitive Design (MSD) was recently developed to facilitate solutions to inverse problems in microstructure design where the goal is to identify the complete set of relevant microstructures that are predicted to satisfy a set of designer specified criteria for effective properties or performance. In this work, MSD has been successfully applied to a few design case studies involving polycrystalline metals and continuous fiber reinforced composites (CFRC). The solutions obtained are, as expected, strongly influenced by the selected homogenization theories. In the case studies presented here, elementary first-order theories are used for both the polycrystalline metals and the continuous fiber reinforced composites. In the composite case, elementary first-order theories spanning two length scales have been selected to obtain effective properties of continuous fiber reinforced composite material systems. Having selected these first-order theories, we proceeded to demonstrate the viability of applying the MSD framework to designing optimal orientation distributions in both polycrystalline metals and continuous fiber reinforced composites for the selected mechanical design problems. Specifically, the mechanical design case study used in this work involved maximizing the load carrying capacity of an orthotropic plate with a circular hole and loaded in in-plane tension. MSD results for this case study show a potential improvement of 27% in nickel polycrystals and 267% improvement in AS4-Epoxy composites investigated in this study. Additionally the mechanical design of a pressure vessel containing a partially through axial flaw is examined; the potential improvement in energy dissipated during crack growth is 31%.

  2. Multiscale materials design of natural exoskeletons : fish armor

    E-print Network

    Song, Juha

    2011-01-01

    Biological materials have developed hierarchical and heterogeneous material nanostructures and microstructures to provide protection against various environmental threats that, in turn, provide bioinspired clues to man-made, ...

  3. Design, synthesis, and evaluation of materials for microelectronics applications

    NASA Astrophysics Data System (ADS)

    Heath, William Hoy

    The advancement of the microelectronics industry is heavily dependent on the design, synthesis, and integration of new materials. Non-chemically amplified photoresists (NCAR) consist of a base resin and photoactive additive which inhibits the dissolution of the this resin. The robustness of NCARs has made them well suited to the unique material requirements of the photomask making industry for many years. However, smaller feature sizes now require mask makers to move to shorter wavelengths of light and thus a more transparent polymer and photoactive compound are needed for these applications. During the search for 157nm photoresists, it was found that polymers containing the hexafluoroisopropanol functionality are transparent well into the ultraviolet region and possess dissolution characteristics similar to the Novolak resins utilized in NCARs. A suitable photoactive compound (PAC) has been identified; the synthesis of the PAC and transparent polymers, as well as their formulation, dissolution properties, and lithographic evaluation will be presented. Additionally, the base catalyzed imidization of poly(amic acid ethyl ester) (PAETE) provides a good tool for developing a photosensitive polyimide insulator. However few base photogenerators (PBG) exist that absorb at the appropriate wavelength (>400nm) for use in these opaque films. Two sensitized systems were evaluated; their synthesis, photophysical evaluation, and attempted imaging in PAETE will be described. Additionally, the synthesis and photophysical evaluation of a red-shifted thiophene-based PBG will be described. Finally, step and flash imprint lithography exhibits a great promise as a cost effective alternative imaging solution to traditional optical lithography. A strippable resist is needed to preserve the templates used in this process should they become contaminated. The thermal reversibility of urethanes, specifically those derived from aromatic oximes, make them well suited for integration into a thermally degradable diacrylate crosslinker. The synthesis of urethane linked diacrylates, their incorporation into cross-linked polymer networks, and thermal degradation will be described.

  4. Eutectics as improved pharmaceutical materials: design, properties and characterization.

    PubMed

    Cherukuvada, Suryanarayan; Nangia, Ashwini

    2014-01-28

    Eutectics are a long known class of multi-component solids with important and useful applications in daily life. In comparison to other multi-component crystalline solids, such as salts, solid solutions, molecular complexes and cocrystals, eutectics are less studied in terms of molecular structure organization and bonding interactions. Classically, a eutectic is defined based on its low melting point compared to the individual components. In this article, we attempt to define eutectics not just based on thermal methods but from a structural organization view point, and discuss their microstructures and properties as organic materials vis-a-vis solid solutions and cocrystals. The X-ray crystal structure of a cocrystal is different from that of the individual components whereas the unit cell of a solid solution is similar to that of one of the components. Eutectics are closer to the latter species in that their crystalline arrangement is similar to the parent components but they are different with respect to the structural integrity. A solid solution possesses structural homogeneity throughout the structure (single phase) but a eutectic is a heterogeneous ensemble of individual components whose crystal structures are like discontinuous solid solutions (phase separated). Thus, a eutectic may be better defined as a conglomerate of solid solutions. A structural analysis of cocrystals, solid solutions and eutectics has led to an understanding that materials with strong adhesive (hetero) interactions between the unlike components will lead to cocrystals whereas those having stronger cohesive (homo/self) interactions will more often give rise to solid solutions (for similar structures of components) and eutectics (for different structures of components). We demonstrate that the same crystal engineering principles which have been profitably utilized for cocrystal design in the past decade can now be applied to make eutectics as novel composite materials, illustrated by stable eutectics of the hygroscopic salt of the anti-tuberculosis drug ethambutol as a case study. A current gap in the characterization of eutectic microstructure may be fulfilled through pair distribution function (PDF) analysis of X-ray diffraction data, which could be a rapid signature technique to differentiate eutectics from their components. PMID:24322207

  5. Functionally Graded Designer Viscoelastic Materials Tailored to Perform Prescribed Tasks with Probabilistic Failures and Lifetimes

    SciTech Connect

    Hilton, Harry H.

    2008-02-15

    Protocols are developed for formulating optimal viscoelastic designer functionally graded materials tailored to best respond to prescribed loading and boundary conditions. In essence, an inverse approach is adopted where material properties instead of structures per se are designed and then distributed throughout structural elements. The final measure of viscoelastic material efficacy is expressed in terms of failure probabilities vs. survival time000.

  6. Technologists Talk: Making the Links between Design, Problem-Solving and Experiences with Hard Materials

    ERIC Educational Resources Information Center

    Potter, Patricia

    2013-01-01

    Design and problem-solving is a key learning focus in technology education and remains a distinguishing factor that separates it from other subject areas. This research investigated how two expert designers considered experiences with hard materials contributed to their learning design and problem-solving with these materials. The research project…

  7. 30 CFR 27.20 - Quality of material, workmanship, and design.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Quality of material, workmanship, and design... TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Construction and Design Requirements § 27.20 Quality of material, workmanship, and design. (a) MSHA will test only equipment that,...

  8. 30 CFR 27.20 - Quality of material, workmanship, and design.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Quality of material, workmanship, and design... TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Construction and Design Requirements § 27.20 Quality of material, workmanship, and design. (a) MSHA will test only equipment that,...

  9. 30 CFR 36.20 - Quality of material, workmanship, and design.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Quality of material, workmanship, and design...-POWERED TRANSPORTATION EQUIPMENT Construction and Design Requirements § 36.20 Quality of material, workmanship, and design. (a) MSHA will test only equipment that in the opinion of its...

  10. 30 CFR 27.20 - Quality of material, workmanship, and design.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Quality of material, workmanship, and design... TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Construction and Design Requirements § 27.20 Quality of material, workmanship, and design. (a) MSHA will test only equipment that,...

  11. Fab trees for designing complex 3D printable materials

    E-print Network

    Wang, Ye, M. Eng. Massachusetts Institute of Technology

    2013-01-01

    With more 3D printable materials being invented, 3D printers nowadays could replicate not only geometries, but also appearance and physical properties. On the software side, the tight coupling between geometry and material ...

  12. Simulation and design optimization of wave propagation in heterogeneous materials

    E-print Network

    Saà-Seoane, Joel

    2014-01-01

    Propagation of waves through heterogeneous structured materials has been the focus of considerable research in recent years. These materials consist of quasi periodic geometries combining two or more piecewise homogeneous ...

  13. Design Considerations of Help Options in Computer-Based L2 Listening Materials Informed by Participatory Design

    ERIC Educational Resources Information Center

    Cárdenas-Claros, Mónica Stella

    2015-01-01

    This paper reports on the findings of two qualitative exploratory studies that sought to investigate design features of help options in computer-based L2 listening materials. Informed by principles of participatory design, language learners, software designers, language teachers, and a computer programmer worked collaboratively in a series of…

  14. Design and evaluation of lost circulation materials for severe environments

    SciTech Connect

    Loeppke, G.E.; Glowka, D.A.; Wright, E.K.

    1988-01-01

    An independent analysis of lost circulation materials for geothermal applications has been completed using unique laboratory tools developed for the purpose. Test results of commercial materials as well as mathematical models for evaluating their performance are presented. Physical attributes that govern the performance of lost circulation materials are identified and correlated with test results. 9 refs., 27 figs., 4 tabs.

  15. Design and material selection for inverter transformer cores

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T.

    1973-01-01

    Report is announced which studied magnetic properties of candidate materials for use in spacecraft transformers, static inverters, converters, and transformer-rectifier power supplies. Included are material characteristics for available alloy compositions in tabular form, including: trade names, saturated flux density, dc coercive force, loop squareness, material density, and watts per pound at 3 KHz.

  16. Category theory based solution for the building block replacement problem in materials design

    E-print Network

    Giesa, Tristan

    An important objective in materials design is to develop a systematic methodology for replacing unavailable or expensive material building blocks by simpler and abundant ones, while maintaining or improving the functionality ...

  17. 46 CFR 160.077-7 - Procedure for approval of design or material revision.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Hybrid Inflatable Personal Flotation Devices § 160.077-7 Procedure for approval of design or material revision....

  18. Systematising EAP Materials Development: Design, Evaluation and Revision in a Thai Undergraduate Reading Course 

    E-print Network

    Sudajit-apa, Melada

    2008-01-01

    Materials design and evaluation have been regarded as inseparable processes for a systematic approach to materials development. But much less attention has been paid to the role and process of revision. This study reports ...

  19. Design of Meta-Materials Outside the Homogenization Limit Using Multiscale Analysis and Topology Optimization

    NASA Astrophysics Data System (ADS)

    Czech, Christopher

    The field of meta-materials engineering has largely expanded mechanical design possibilities over the last two decades; some notable design advances include the systematic engineering of negative Poisson's ratio materials and functionally graded materials, materials designed for optimal electronic and thermo-mechanical performances, and the design of materials under uncertainty. With these innovations, the systematic engineering of materials for design-specific uses is becoming more common in industrial and military uses. The motivation for this body of research is the design of the shear beam for a non-pneumatic wheel. Previously, a design optimization of a finite element model of the non-pneumatic wheel was completed, where a linear elastic material was simulated in the shear beam to reduce hysteretic energy losses. As part of the optimization, a set of optimal orthotropic material properties and other geometric properties were identified for the shear beam. Given that no such natural linear elastic material exists, a meta-material can be engineered that meets these properties using the aforementioned tools. However, manufacturing constraints prevent the use of standard homogenization analysis and optimization tools in the engineering of the shear beam due to limitations in the accuracy of the homogenization process for thin materials. In this research, the more general volume averaging analysis is shown to be an accurate tool for meta-material analysis for engineering thin-layered materials. Given an accurate analysis method, several optimization formulations are proposed, and optimality conditions are derived to determine the most mathematically feasible and numerically reliable formulation for topology optimization of a material design problem using a continuous material interpolation over the design domain. This formulation is implemented to engineer meta-materials for problems using the volume averaging analysis, which includes the use of variable linking and the derivation of first-order design sensitivities to increase computational efficiency. Inspired by honeycomb materials, a new method of discretizing the material design domain into unit cells with non-simple connectivity is proposed as a way of increasing the solution space of the topology optimization problem. Finally, these methods are used in the meta-material design process to identify several candidate meta-material geometries from a polycarbonate base material for the shear layer of the non-pneumatic wheel; notable geometries include an 'x'-like geometry, a bent column-like geometry identified previously as a bristle, and, remarkably, an auxetic honeycomb geometry. This is the first reported result demonstrating the auxetic honeycomb geometry to be a minimum weight structure in shear loading where a general topology optimization method was used.

  20. Towards intelligent microstructural design of Nanocomposite Materials. Lightweight, high strength structural/armor materials for service in extreme environments

    SciTech Connect

    Mara, Nathan Allan; Bronkhorst, Curt Allan; Beyerlein, Irene Jane

    2015-12-21

    The intent of this research effort is to prove the hypothesis that: Through the employment of controlled processing parameters which are based upon integrated advanced material characterization and multi-physics material modeling, bulk nanolayered composites can be designed to contain high densities of preferred interfaces that can serve as supersinks for the defects responsible for premature damage and failure.

  1. Role of dislocation theory in the design of engineering materials

    SciTech Connect

    Morris, J.W. Jr.

    1980-06-01

    The science of materials development has progressed to a stage in which it is possible to compose a recipe for new materials. The recipe has three steps: given a desirable set of properties and material constraints, one identifies a composition and microstructure to achieve them; given a desirable composition and microstructure, one identifies a processing sequence to achieve them; given a trial alloy, one conducts analytical testing to identify its shortcomings and overcomes them. In effecting each stage of this recipe, it is usually necessary to be aware of and understand the role of the dislocations which determine material properties, define material microstructure, and control its evolution. The role of dislocations is discussed. The text contains examples of particular alloy development efforts, and suggestions for research in dislocation theory which might contribute to the solution of significant problems in materials development.

  2. Stratification, Elaboration and Formalisation of Design Documents: Effects on the Production of Instructional Materials

    ERIC Educational Resources Information Center

    Boot, Eddy W.; Nelson, Jon; van Merrienboer, Jeroen J. G.; Gibbons, Andrew S.

    2007-01-01

    Designers and producers of instructional materials lack a common design language. As a result, producers have difficulties translating design documents into technical specifications. The 3D-model is introduced to improve the stratification, elaboration and formalisation of design documents. It is hypothesised that producers working with improved…

  3. The Design of Reactions, Catalysts and Materials with Aromatic Ions

    NASA Astrophysics Data System (ADS)

    Bandar, Jeffrey Scott

    This thesis details the use of aromatic ions, especially aminocyclopropenium ions, as empowering design elements in the development of new chemical reactions, organic catalysts and polymeric materials. A particular focus is placed throughout on understanding the relationship between the structure of aromatic ions and their performance in these novel applications. Additionally, the benefits that aromatic ions provide in these contexts are highlighted. The first chapter briefly summarizes the Lambert Group's prior efforts toward exploiting the unique reactivity profiles of aromatic ions in the context of new reaction design. Also provided in the first chapter is a comprehensive literature review of aminocyclopropenium ions, upon which the majority of advances described in this thesis are based. To set the stage for the first application of aminocyclopropenium ions, Chapter 2 provides an account of existing highly Bronsted basic functional groups, including guanidines, proazaphosphatranes and iminophosphoranes. The provided review on the synthesis and use in asymmetric catalysis of these bases indicates that there is a high need for conceptually new Bronsted basic functional groups. To address this need, the development of chiral 2,3-bis(dialkylamino)cyclopropenimines as a new platform for asymmetric Bronsted base catalysis is described in Chapter 3. This new class of Bronsted base is readily synthesized on scale, operates efficiently under practical conditions, and greatly outperforms closely related guanidine-based catalysts. Structure-activity relationship studies, mechanistic experiments and computational transition state modeling are all discussed in the context of asymmetric glycinate imine Michael reactions in order to arrive at a working model for cyclopropenimine chemistry. Cumulatively, this chapter provides a "user's guide" to understanding and developing further applications of 2,3-bis(dialkylamino)cyclopropenimines. The use of our optimal chiral 2,3-bis(dialkylamino)cyclopropenimine catalyst to promote asymmetric Mannich reactions of glycinate imines and N -Boc-aldimines is described in Chapter 4. The products of this transformation are optically enriched diamino acid derivatives, an important motif widely utilized in medicinal and synthetic chemistry. Importantly, unlike existing methods, our technology promotes reactions between tert-butyl glycinate and aliphatic N-Boc-aldimine substrates. A preparative-scale reaction is demonstrated and derivatization of its product to several valuable chiral compounds is shown. Chapter 5 describes the use of tris(dialkylamino)cyclopropenium (TDAC) ions as a new class of onium-like catalyst. A simple TDAC chloride salt is prepared on a 75-gram scale and its use as a phase transfer catalyst for a variety of reactions is demonstrated. This same salt is also utilized as an epoxide opening catalyst for a variety of transformations, including the fixation of carbon dioxide. Chapter 6 briefly highlights several continued applications of the chemistry advanced throughout this thesis. First, the work of other members of the Lambert Group toward the continued development of cyclopropenimine chemistry is described. Second, a broad initiative between the Lambert and Campos Groups at Columbia University focused on the synthesis and application of TDAC-based polymers is introduced. Lastly, the identification of a previously unknown equilibrium between fulvenes and imines/aldehydes in the context of a new mode of catalysis is presented.

  4. Mechanical design engineering. NASA/university advanced design program: Lunar Bulk Material Transport Vehicle

    NASA Technical Reports Server (NTRS)

    Daugherty, Paul; Griner, Stewart; Hendrix, Alan; Makarov, Chris; Martiny, Stephen; Meyhoefer, Douglas Ralph; Platt, Cody Claxton; Sivak, John; Wheeler, Elizabeth Fitch

    1988-01-01

    The design of a Lunar Bulk Material Transport Vehicle (LBMTV) is discussed. Goals set in the project include a payload of 50 cubic feet of lunar soil with a lunar of approximately 800 moon-pounds, a speed of 15 mph, and the ability to handle a grade of 20 percent. Thermal control, an articulated steering mechanism, a dump mechanism, a self-righting mechanism, viable power sources, and a probable control panel are analyzed. The thermal control system involves the use of small strip heaters to heat the housing of electronic equipment in the absence of sufficient solar radiation and multi-layer insulation during periods of intense solar radiation. The entire system uses only 10 W and weighs about 60 pounds, or 10 moon-pounds. The steering mechanism is an articulated steering joint at the center of the vehicle. It utilizes two actuators and yields a turning radius of 10.3 feet. The dump mechanism rotates the bulk material container through an angle of 100 degree using one actuator. The self-righting mechanism consists of two four bar linkages, each of which is powered by the same size actuator as the other linkages. The LBMTV is powered by rechargeable batteries. A running time of at least two hours is attained under a worst case analysis. The weight of the batteries is 100 pounds. A control panel consisting of feedback and control instruments is described. The panel includes all critical information necessary to control the vehicle remotely. The LBMTV is capable of handling many types of cargo. It is able to interface with many types of removable bulk material containers. These containers are made to interface with the three-legged walker, SKITTER. The overall vehicle is about 15 feet in length and has a weight of about 1000 pounds, or 170 lunar pounds.

  5. Materials by Design—A Perspective From Atoms to Structures

    PubMed Central

    Buehler, Markus J.

    2013-01-01

    Biological materials are effectively synthesized, controlled, and used for a variety of purposes—in spite of limitations in energy, quality, and quantity of their building blocks. Whereas the chemical composition of materials in the living world plays a some role in achieving functional properties, the way components are connected at different length scales defines what material properties can be achieved, how they can be altered to meet functional requirements, and how they fail in disease states and other extreme conditions. Recent work has demonstrated this by using large-scale computer simulations to predict materials properties from fundamental molecular principles, combined with experimental work and new mathematical techniques to categorize complex structure-property relationships into a systematic framework. Enabled by such categorization, we discuss opportunities based on the exploitation of concepts from distinct hierarchical systems that share common principles in how function is created, linking music to materials science. PMID:24163499

  6. Material and Color Design Using Projectors Jonathan Konieczny and Gary Meyer

    E-print Network

    Meyer, Gary

    Material and Color Design Using Projectors Jonathan Konieczny and Gary Meyer University design. The system explores tech- niques for simulation of color on real objects lit by projectors, USA Abstract A novel front projection system is introduced for the pur- pose of material and color

  7. 36 CFR 401.5 - Control and supervision of materials, design, and building.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Control and supervision of materials, design, and building. 401.5 Section 401.5 Parks, Forests, and Public Property AMERICAN BATTLE MONUMENTS COMMISSION MONUMENTS AND MEMORIALS § 401.5 Control and supervision of materials, design,...

  8. Designing Web-Based Educative Curriculum Materials for the Social Studies

    ERIC Educational Resources Information Center

    Callahan, Cory; Saye, John; Brush, Thomas

    2013-01-01

    This paper reports on a design experiment of web-based curriculum materials explicitly created to help social studies teachers develop their professional teaching knowledge. Web-based social studies curriculum reform efforts, human-centered interface design, and investigations into educative curriculum materials are reviewed, as well as…

  9. MINIMIZING THE ENVIRONMENTAL IMPACT OF CONSTRUCTION MATERIALS IN PLAYGROUND DESIGN

    EPA Science Inventory

    We are a playground design team at Louisiana State University that has been involved with playground design projects for the past seven years. Playgrounds are extremely important to society because they promote the physical, mental, and social well being of children. ...

  10. First Materials Science Research Rack Capabilities and Design Features

    NASA Technical Reports Server (NTRS)

    Schaefer, D.; King, R.; Cobb, S.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    The first Materials Science Research Rack (MSRR-1) will accommodate dual Experiment Modules (EM's) and provide simultaneous on-orbit processing operations capability. The first international Materials Science Experiment Module for the MSRR-1 is an international cooperative research activity between NASA's Marshall Space Flight Center (MSFC) and the European Space Agency's (ESA) European Space Research and Technology Center. (ESTEC). This International Standard Payload Rack (ISPR) will contain the Materials Science Laboratory (MSL) developed by ESA as an Experiment Module. The MSL Experiment Module will accommodate several on-orbit exchangeable experiment-specific Module Inserts. Module Inserts currently planned are a Quench Module Insert, Low Gradient Furnace, Solidification with Quench Furnace, and Diffusion Module Insert. The second Experiment Module for the MSRR-1 configuration is a commercial device supplied by MSFC's Space Products Department (SPD). It includes capabilities for vapor transport processes and liquid metal sintering. This Experiment Module will be replaced on-orbit with other NASA Materials Science EMs.

  11. Design and Discovery of Highly Efficient Thermoelectric Materials

    NASA Technical Reports Server (NTRS)

    Fleurial, J. P.

    1998-01-01

    Thermoelectric energy conversion efficiency is directly related to the temperature difference over which the device operates, its average temperature of operation and the transport properties of the thermocouple material represented by ZT, the dimensionless figure of merit.

  12. Design of novel lithium storage materials with a polyanionic framework

    E-print Network

    Kim, Jae Chul, Ph. D. Massachusetts Institute of Technology

    2014-01-01

    Lithium ion batteries for large-scale applications demand a strict safety standard from a cathode material during operating cycles. Lithium manganese borate (LiMnBO?) that crystallizes into a hexagonal or monoclinic framework ...

  13. Optimal Design and Scheduling of Unsteady State Material Recovery Networks 

    E-print Network

    Rabie, Arwa H.

    2010-01-14

    This research developed novel methodologies to achieve cost effective solutions to overcome many of the difficulties associated with unsteady state material recovery network synthesis. The work focuses on the development ...

  14. Design and fabrication of granular materials for surface acoustic waves

    E-print Network

    Gan, Tian, S.M. Massachusetts Institute of Technology

    2015-01-01

    Granular materials with structural discreteness and periodicity can lead to novel propagation behaviors of mechanical waves. Acoustic studies of granular media typically involve macroscopic particles whereas contact-based ...

  15. STOCHASTIC DESIGN AND CONTROL IN RANDOM HETEROGENEOUS MATERIALS

    E-print Network

    Del Moral , Pierre

    in the macroscale response. In reality, the majority of such materials exhibit randomness as local physical such as solidification or stabilization allow us to alter the microstructure and its properties by altering

  16. Knitting behavior : a material-centric design process

    E-print Network

    McKnelly, Carrie Lee

    2015-01-01

    This thesis explores computation as a communicative device between the physical and the digital, establishing a conversation between a material assembly and a digital model as a tool to inform the logic of the assembly's ...

  17. Use of UHPC in Bridge Structures: Material Modeling and Design

    E-print Network

    Gunes, Oguz

    Ultra-high-performance concrete (UHPC) is a promising new class of concrete material that is likely to make a significant contribution to addressing the challenges associated with the load capacity, durability, sustainability, ...

  18. Design, Synthesis, and Characterization of Porous Metal-Organic Materials 

    E-print Network

    Park, Jinhee

    2013-04-19

    Porous metal-organic materials (MOMs) are assembled through coordination between two types of building units, metal or metal-containing nodes and organic linkers. Metal-organic frameworks (MOFs) have 3-D infinite structures and are especially known...

  19. Materials technology assessment for a 1050 K Stirling space engine design

    NASA Technical Reports Server (NTRS)

    Scheuermann, Coulson M.; Dreshfield, Robert L.; Gaydosh, Darrell J.; Kiser, James D.; Mackay, Rebecca A.; Mcdaniels, David L.; Petrasek, Donald W.; Vannucci, Raymond D.; Bowles, Kenneth J.; Watson, Gordon K.

    1988-01-01

    An assessment of materials technology and proposed materials selection was made for the 1050 K (superalloy) Stirling Space Engine design. The objectives of this assessment were to evaluate previously proposed materials selections, evaluate the current state-of-the-art materials, propose potential alternate materials selections and identify research and development efforts needed to provide materials that can meet the stringent system requirements. This assessment generally reaffirmed the choices made by the contractor. However, in many cases alternative choices were described and suggestions for needed materials and fabrication research and development were made.

  20. Materials technology assessment for a 1050 K Stirling Space Engine design

    SciTech Connect

    Scheuermann, C.M.; Dreshfield, R.L.; Gaydosh, D.J.; Kiser, J.D.; MacKay, R.A.; McDanels, D.L.; Petrasek, D.W.; Vannucci, R.D.; Bowles, K.J.; Watson, G.K.

    1988-10-01

    An assessment of materials technology and proposed materials selection was made for the 1050 K (superalloy) Stirling Space Engine design. The objectives of this assessment were to evaluate previously proposed materials selections, evaluate the current state-of-the-art materials, propose potential alternate materials selections and identify research and development efforts needed to provide materials that can meet the stringent system requirements. This assessment generally reaffirmed the choices made by the contractor; however, in many cases alternative choices were described and suggestions for needed materials and fabrication research and development were made.

  1. Bioreceptivity evaluation of cementitious materials designed to stimulate biological growth.

    PubMed

    Manso, Sandra; De Muynck, Willem; Segura, Ignacio; Aguado, Antonio; Steppe, Kathy; Boon, Nico; De Belie, Nele

    2014-05-15

    Ordinary Portland cement (OPC), the most used binder in construction, presents some disadvantages in terms of pollution (CO2 emissions) and visual impact. For this reason, green roofs and façades have gain considerable attention in the last decade as a way to integrate nature in cities. These systems, however, suffer from high initial and maintenance costs. An alternative strategy to obtain green facades is the direct natural colonisation of the cementitious construction materials constituting the wall, a phenomenon governed by the bioreceptivity of such material. This work aims at assessing the suitability of magnesium phosphate cement (MPC) materials to allow a rapid natural colonisation taking carbonated OPC samples as a reference material. For that, the aggregate size, the w/c ratio and the amount of cement paste of mortars made of both binders were modified. The assessment of the different bioreceptivities was conducted by means of an accelerated algal fouling test. MPC samples exhibited a faster fouling compared to OPC samples, which could be mainly attributed to the lower pH of the MPC binder. In addition to the binder, the fouling rate was governed by the roughness and the porosity of the material. MPC mortar with moderate porosity and roughness appears to be the most feasible material to be used for the development of green concrete walls. PMID:24602907

  2. Design elements for the development of cancer education print materials for a Latina/o audience.

    PubMed

    Buki, Lydia P; Salazar, Silvia I; Pitton, Viviana O

    2009-10-01

    Health educators can help reduce cancer disparities in Latino populations through the creation of effective print materials. In this effort, the National Cancer Institute conducted a comprehensive needs assessment to identify key design elements of cancer education programs and create a cost-effective process that would ensure consistency in the development of materials. This article introduces the Checklist of Design Elements for the Development of Cancer Education Print Materials for Latina/o Audiences (CEMLA), which includes a total of 10 design elements related to the process of developing materials and content. Using social learning theory as a theoretical framework, design elements are included that reflect cultural sensitivity at the surface and deep structure levels. This is the most comprehensive effort to date to integrate and synthesize theory and application in the design of materials for this audience. PMID:19098265

  3. Microwave Nondestructive Evaluation of Dielectric Materials with a Metamaterial Lens

    NASA Technical Reports Server (NTRS)

    Shreiber, Daniel; Gupta, Mool; Cravey, Robin L.

    2008-01-01

    A novel microwave Nondestructive Evaluation (NDE) sensor was developed in an attempt to increase the sensitivity of the microwave NDE method for detection of defects small relative to a wavelength. The sensor was designed on the basis of a negative index material (NIM) lens. Characterization of the lens was performed to determine its resonant frequency, index of refraction, focus spot size, and optimal focusing length (for proper sample location). A sub-wavelength spot size (3 dB) of 0.48 lambda was obtained. The proof of concept for the sensor was achieved when a fiberglass sample with a 3 mm diameter through hole (perpendicular to the propagation direction of the wave) was tested. The hole was successfully detected with an 8.2 cm wavelength electromagnetic wave. This method is able to detect a defect that is 0.037 lambda. This method has certain advantages over other far field and near field microwave NDE methods currently in use.

  4. A simple simulation method for designing fibrous insulation materials R. Arambakam a

    E-print Network

    Tafreshi, Hooman Vahedi

    to predict thermal insulation properties in terms of SVF and thermal conductivity of solid and interstitialA simple simulation method for designing fibrous insulation materials R. Arambakam a , H. Vahedi: Conductive heat transfer Fibrous materials Insulation materials Numerical simulation a b s t r a c

  5. 46 CFR 128.240 - Hydraulic or pneumatic power and control-materials and pressure design.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Hydraulic or pneumatic power and control-materials...Materials and Pressure Design § 128.240 Hydraulic or pneumatic power and control—materials...flanges, and standard valves) for hydraulic or pneumatic power and control...

  6. Elementary Students' Learning of Materials Science Practices through Instruction Based on Engineering Design Tasks

    ERIC Educational Resources Information Center

    Wendell, Kristen Bethke; Lee, Hee-Sun

    2010-01-01

    Materials science, which entails the practices of selecting, testing, and characterizing materials, is an important discipline within the study of matter. This paper examines how third grade students' materials science performance changes over the course of instruction based on an engineering design challenge. We conducted a case study of nine…

  7. 14 CFR 29.613 - Material strength properties and design values.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...design values that assure material strength with the following...HDBK-5, “Metallic Materials and Elements for Flight Vehicle... (4) MIL—HDBK-23, “Composite Construction for Flight Vehicles...used if a selection of the material is made in which a...

  8. 14 CFR 27.613 - Material strength properties and design values.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...design values that assure material strength with the following...MIL-HDBK-5, “Metallic Materials and Elements for Flight Vehicle... (4) MIL-HDBK-23, “Composite Construction for Flight Vehicles...used if a selection of the material is made in which a...

  9. 14 CFR 29.613 - Material strength properties and design values.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...design values that assure material strength with the following...HDBK-5, “Metallic Materials and Elements for Flight Vehicle... (4) MIL—HDBK-23, “Composite Construction for Flight Vehicles...used if a selection of the material is made in which a...

  10. 14 CFR 27.613 - Material strength properties and design values.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...design values that assure material strength with the following...MIL-HDBK-5, “Metallic Materials and Elements for Flight Vehicle... (4) MIL-HDBK-23, “Composite Construction for Flight Vehicles...used if a selection of the material is made in which a...

  11. 14 CFR 27.613 - Material strength properties and design values.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...design values that assure material strength with the following...MIL-HDBK-5, “Metallic Materials and Elements for Flight Vehicle... (4) MIL-HDBK-23, “Composite Construction for Flight Vehicles...used if a selection of the material is made in which a...

  12. 14 CFR 27.613 - Material strength properties and design values.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...design values that assure material strength with the following...MIL-HDBK-5, “Metallic Materials and Elements for Flight Vehicle... (4) MIL-HDBK-23, “Composite Construction for Flight Vehicles...used if a selection of the material is made in which a...

  13. 14 CFR 29.613 - Material strength properties and design values.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...design values that assure material strength with the following...HDBK-5, “Metallic Materials and Elements for Flight Vehicle... (4) MIL—HDBK-23, “Composite Construction for Flight Vehicles...used if a selection of the material is made in which a...

  14. 14 CFR 29.613 - Material strength properties and design values.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...design values that assure material strength with the following...HDBK-5, “Metallic Materials and Elements for Flight Vehicle... (4) MIL—HDBK-23, “Composite Construction for Flight Vehicles...used if a selection of the material is made in which a...

  15. 14 CFR 29.613 - Material strength properties and design values.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...design values that assure material strength with the following...HDBK-5, “Metallic Materials and Elements for Flight Vehicle... (4) MIL—HDBK-23, “Composite Construction for Flight Vehicles...used if a selection of the material is made in which a...

  16. 14 CFR 27.613 - Material strength properties and design values.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...design values that assure material strength with the following...MIL-HDBK-5, “Metallic Materials and Elements for Flight Vehicle... (4) MIL-HDBK-23, “Composite Construction for Flight Vehicles...used if a selection of the material is made in which a...

  17. A database to enable discovery and design of piezoelectric materials

    PubMed Central

    de Jong, Maarten; Chen, Wei; Geerlings, Henry; Asta, Mark; Persson, Kristin Aslaug

    2015-01-01

    Piezoelectric materials are used in numerous applications requiring a coupling between electrical fields and mechanical strain. Despite the technological importance of this class of materials, for only a small fraction of all inorganic compounds which display compatible crystallographic symmetry, has piezoelectricity been characterized experimentally or computationally. In this work we employ first-principles calculations based on density functional perturbation theory to compute the piezoelectric tensors for nearly a thousand compounds, thereby increasing the available data for this property by more than an order of magnitude. The results are compared to select experimental data to establish the accuracy of the calculated properties. The details of the calculations are also presented, along with a description of the format of the database developed to make these computational results publicly available. In addition, the ways in which the database can be accessed and applied in materials development efforts are described. PMID:26451252

  18. A database to enable discovery and design of piezoelectric materials.

    PubMed

    de Jong, Maarten; Chen, Wei; Geerlings, Henry; Asta, Mark; Persson, Kristin Aslaug

    2015-01-01

    Piezoelectric materials are used in numerous applications requiring a coupling between electrical fields and mechanical strain. Despite the technological importance of this class of materials, for only a small fraction of all inorganic compounds which display compatible crystallographic symmetry, has piezoelectricity been characterized experimentally or computationally. In this work we employ first-principles calculations based on density functional perturbation theory to compute the piezoelectric tensors for nearly a thousand compounds, thereby increasing the available data for this property by more than an order of magnitude. The results are compared to select experimental data to establish the accuracy of the calculated properties. The details of the calculations are also presented, along with a description of the format of the database developed to make these computational results publicly available. In addition, the ways in which the database can be accessed and applied in materials development efforts are described. PMID:26451252

  19. Robotic Materials Handling in Space: Mechanical Design of the Robot Operated Materials Processing System HitchHiker Experiment

    NASA Technical Reports Server (NTRS)

    Voellmer, George

    1997-01-01

    The Goddard Space Flight Center has developed the Robot Operated Materials Processing System (ROMPS) that flew aboard STS-64 in September, 1994. The ROMPS robot transported pallets containing wafers of different materials from their storage racks to a furnace for thermal processing. A system of tapered guides and compliant springs was designed to deal with the potential misalignments. The robot and all the sample pallets were locked down for launch and landing. The design of the passive lockdown system, and the interplay between it and the alignment system are presented.

  20. Comparison of gap frame designs and materials for precision cathode strip chambers

    SciTech Connect

    Horvath, J.A.; Pratuch, S.M.; Belser, F.C.

    1993-09-16

    Precision cathode strip chamber perimeter designs that incorporate either continuous or discrete-post gap frames are analyzed. The effects of ten design and material combinations on gravity sag, mass, stress, and deflected shape are evaluated. Procedures are recommended for minimizing mass in the chamber perimeter region while retaining structural integrity and electrical design latitude.

  1. Bridging the Design-Manufacturing-Materials Data Gap: Material Properties for Optimum Design and Manufacturing Performance in Light Vehicle Steel-Intensive Body Structures

    NASA Astrophysics Data System (ADS)

    Zuidema, Blake K.

    2012-09-01

    As safety and fuel economy regulations become increasingly more challenging around the world, light vehicle manufacturers are facing increasing pressure to reduce the weight of their vehicles cost effectively while maintaining or improving safety performance. Optimum light vehicle steel body structure weight and performance are achieved when the constraints of design, manufacturing, and material properties are considered simultaneously. ArcelorMittal has invested heavily over the past several years to close the gap between material property knowledge and the inter-relation between material performance and design and manufacturing efficiency. Knowledge gained through this process is presented and the importance of achieving this simultaneous 3-way optimization is illustrated by a lightweight steel door design example from ArcelorMittal's S-in motion catalog of lightweight steel solutions.

  2. Design of a scientific probe for obtaining Mars surface material

    NASA Technical Reports Server (NTRS)

    1990-01-01

    With the recent renewed interest in interplanetary and deep space exploratory missions, the Red Planet, Mars, which has captured people's imagination for centuries, has again become a center of attention. In the late 1960s and early 1970s, a series of Mariner missions performed fly-by investigations of the Mars surface and atmosphere. Later, in the mid 1970s, the data gathered by these earlier Mariner missions provided the basis of the much-publicized Viking missions, whose main objective was to determine the possibility of extraterrestrial life on Mars. More recently, with the dramatic changes in international politics, ambitious joint manned missions between the United States and the Soviet Union have been proposed to be launched in the early 21st century. In light of these exciting developments, the Spacecraft Design course, which was newly established at UCLA under NASA/USRA sponsorship, has developed its curriculum around a design project: the synthesis of an unmanned Martian landing probe. The students are required to conceive a preliminary design of a small spacecraft that is capable of landing at a designated site, collecting soil samples, and then returning the samples to orbit. The goal of the project is to demonstrate the feasibility of such a mission. This preliminary study of an interplanetary exploration mission has shown the feasibility of such a mission. The students have learned valuable lessons about the complexity of spacecraft design, even though the mission is relatively simple.

  3. Performance of pavements designed with low-cost materials

    NASA Astrophysics Data System (ADS)

    Grau, R. W.; Yrjanson, W. A.; Packard, R. G.; Barksdale, R. D.; Potts, C. F.; Ruth, B. E.; Smith, L. L.; Huddleston, I. J.; Vinson, T. S.; Hicks, R. G.

    1980-04-01

    The following areas are discussed. Utilization of marginal aggregate materials for secondary road surface layers; econocrete pavements; current practices; construction and performance of sand-asphalt bases and performance of sand-asphalt and limerock pavements in Florida. Cement stabilization of degrading aggregates use of crushed stone screenings in highway construction (abridgement); and sulfur-asphalt pavement technology are also reviewed.

  4. The Empirical Attitude, Material Practice and Design Activities

    ERIC Educational Resources Information Center

    Apedoe, Xornam; Ford, Michael

    2010-01-01

    This article is an argument about something that is both important and severely underemphasized in most current science curricula. The empirical attitude, fundamental to science since Galileo, is a habit of mind that motivates an active search for feedback on our ideas from the material world. Although more simple views of science manifest the…

  5. NANOSTRUCTURED MATERIAL DESIGN FOR HG, AS, AND SE CAPTURE

    EPA Science Inventory

    The goal of this research project is to identify potential materials that can be used as multipollutant sorbents using a hierarchy of computational modeling approaches. Palladium (Pd) and gold (Au) alloys were investigated and the results show that the addition of a small amou...

  6. Photovoltaic module encapsulation design and materials section, volume 2

    NASA Technical Reports Server (NTRS)

    Cuddihy, E. F.

    1984-01-01

    Tests for chemical structure, material properties, water absorption, aging and curing agent of Ethylene Vinyl Acetate (EVA) and UV absorption studies are carried out. A computer model was developed for thermal optical modeling, to investigate dependence between module operating temperature and solar insolation, and heat dissapation behavior. Structural analyses were performed in order to determine the stress distribution under wind and heat conditions. Curves are shown for thermal loading conditions. An electrical isolation was carried out to investigate electrical stress aging of non-metallic encapsulation materials and limiting material flaws, and to develop a computer model of electrical fields and stresses in encapsulation materials. In addition, a mathematical model was developed and tests were conducted to predict hygroscopic and thermal expansion and contraction on a plastic coated wooden substrate. Thermal cycle and humidity freezing cycle tests, partial discharge tests, and hail impact tests were also carried out. Finally, the effects of soiling on the surface of photovoltaic modules were investigated. Two antisoiling coatings, a fluorinated silane and perflourodecanoic acid were considered.

  7. Mapping Chemical Selection Pathways for Designing Multicomponent Alloys: an informatics framework for materials design.

    PubMed

    Srinivasan, Srikant; Broderick, Scott R; Zhang, Ruifeng; Mishra, Amrita; Sinnott, Susan B; Saxena, Surendra K; LeBeau, James M; Rajan, Krishna

    2015-01-01

    A data driven methodology is developed for tracking the collective influence of the multiple attributes of alloying elements on both thermodynamic and mechanical properties of metal alloys. Cobalt-based superalloys are used as a template to demonstrate the approach. By mapping the high dimensional nature of the systematics of elemental data embedded in the periodic table into the form of a network graph, one can guide targeted first principles calculations that identify the influence of specific elements on phase stability, crystal structure and elastic properties. This provides a fundamentally new means to rapidly identify new stable alloy chemistries with enhanced high temperature properties. The resulting visualization scheme exhibits the grouping and proximity of elements based on their impact on the properties of intermetallic alloys. Unlike the periodic table however, the distance between neighboring elements uncovers relationships in a complex high dimensional information space that would not have been easily seen otherwise. The predictions of the methodology are found to be consistent with reported experimental and theoretical studies. The informatics based methodology presented in this study can be generalized to a framework for data analysis and knowledge discovery that can be applied to many material systems and recreated for different design objectives. PMID:26681142

  8. Mapping Chemical Selection Pathways for Designing Multicomponent Alloys: an informatics framework for materials design

    PubMed Central

    Srinivasan, Srikant; Broderick, Scott R.; Zhang, Ruifeng; Mishra, Amrita; Sinnott, Susan B.; Saxena, Surendra K.; LeBeau, James M.; Rajan, Krishna

    2015-01-01

    A data driven methodology is developed for tracking the collective influence of the multiple attributes of alloying elements on both thermodynamic and mechanical properties of metal alloys. Cobalt-based superalloys are used as a template to demonstrate the approach. By mapping the high dimensional nature of the systematics of elemental data embedded in the periodic table into the form of a network graph, one can guide targeted first principles calculations that identify the influence of specific elements on phase stability, crystal structure and elastic properties. This provides a fundamentally new means to rapidly identify new stable alloy chemistries with enhanced high temperature properties. The resulting visualization scheme exhibits the grouping and proximity of elements based on their impact on the properties of intermetallic alloys. Unlike the periodic table however, the distance between neighboring elements uncovers relationships in a complex high dimensional information space that would not have been easily seen otherwise. The predictions of the methodology are found to be consistent with reported experimental and theoretical studies. The informatics based methodology presented in this study can be generalized to a framework for data analysis and knowledge discovery that can be applied to many material systems and recreated for different design objectives. PMID:26681142

  9. A Practical Approach To Preform Design For Different Materials

    SciTech Connect

    Harrer, Otto; Ruef, Guntram; Buchmayr, Bruno; Sommitsch, Christof

    2007-04-07

    To forge an H-shaped cross section, various preform designs have been tested for steel 42CrMo4, aluminum 7075 and nickel base alloy 80 A (Bohler L306). The influence of different boundary conditions like temperature and friction on the preform and hence on the forming process have been investigated by means of two dimensional finite element analyses. Furthermore, the influence of the preform on the microstructure was computed and the structural damage evolution in the forged parts depending on the preform design has been considered for alloy 80 A.

  10. Nonstoichiometric Laser Materials: Designer Wavelengths in Neodymium Doped Garnets

    NASA Technical Reports Server (NTRS)

    Walsh, Brian M.; Barnes, Norman P.

    2008-01-01

    The tunable nature of lasers provides for a wide range of applications. Most applications rely on finding available laser wavelengths to meet the needs of the research. This article presents the concept of compositional tuning, whereby the laser wavelength is designed by exploiting nonstoichiometry. For research where precise wavelengths are required, such as remote sensing, this is highly advantageous. A theoretical basis for the concept is presented and experimental results in spectroscopic measurements support the theoretical basis. Laser operation nicely demonstrates the validity of the concept of designer lasers.

  11. Structural design methodologies for ceramic-based material systems

    NASA Technical Reports Server (NTRS)

    Duffy, Stephen F.; Chulya, Abhisak; Gyekenyesi, John P.

    1991-01-01

    One of the primary pacing items for realizing the full potential of ceramic-based structural components is the development of new design methods and protocols. The focus here is on low temperature, fast-fracture analysis of monolithic, whisker-toughened, laminated, and woven ceramic composites. A number of design models and criteria are highlighted. Public domain computer algorithms, which aid engineers in predicting the fast-fracture reliability of structural components, are mentioned. Emphasis is not placed on evaluating the models, but instead is focused on the issues relevant to the current state of the art.

  12. A Practical Approach To Preform Design For Different Materials

    NASA Astrophysics Data System (ADS)

    Harrer, Otto; Sommitsch, Christof; Rüf, Guntram; Buchmayr, Bruno

    2007-04-01

    To forge an H-shaped cross section, various preform designs have been tested for steel 42CrMo4, aluminum 7075 and nickel base alloy 80 A (Bohler L306). The influence of different boundary conditions like temperature and friction on the preform and hence on the forming process have been investigated by means of two dimensional finite element analyses. Furthermore, the influence of the preform on the microstructure was computed and the structural damage evolution in the forged parts depending on the preform design has been considered for alloy 80 A.

  13. Materials Design and Discovery with High-Throughput Density Functional Theory: The Open Quantum Materials Database (OQMD)

    NASA Astrophysics Data System (ADS)

    Saal, James E.; Kirklin, Scott; Aykol, Muratahan; Meredig, Bryce; Wolverton, C.

    2013-11-01

    High-throughput density functional theory (HT DFT) is fast becoming a powerful tool for accelerating materials design and discovery by the amassing tens and even hundreds of thousands of DFT calculations in large databases. Complex materials problems can be approached much more efficiently and broadly through the sheer quantity of structures and chemistries available in such databases. Our HT DFT database, the Open Quantum Materials Database (OQMD), contains over 200,000 DFT calculated crystal structures and will be freely available for public use at http://oqmd.org. In this review, we describe the OQMD and its use in five materials problems, spanning a wide range of applications and materials types: (I) Li-air battery combination catalyst/electrodes, (II) Li-ion battery anodes, (III) Li-ion battery cathode coatings reactive with HF, (IV) Mg-alloy long-period stacking ordered (LPSO) strengthening precipitates, and (V) training a machine learning model to predict new stable ternary compounds.

  14. Effects of Buckling Knockdown Factor, Internal Pressure and Material on the Design of Stiffened Cylinders

    NASA Technical Reports Server (NTRS)

    Lovejoy, Andrew E.; Hilburger, Mark W.; Chunchu, Prasad B.

    2010-01-01

    A design study was conducted to investigate the effect shell buckling knockdown factor (SBKF), internal pressure and aluminum alloy material selection on the structural weight of stiffened cylindrical shells. Two structural optimization codes were used for the design study to determine the optimum minimum-weight design for a series of design cases, and included an in-house developed genetic algorithm (GA) code and PANDA2. Each design case specified a unique set of geometry, material, knockdown factor combinations and loads. The resulting designs were examined and compared to determine the effects of SBKF, internal pressure and material selection on the acreage design weight and controlling failure mode. This design study shows that use of less conservative SBKF values, including internal pressure, and proper selection of material alloy can result in significant weight savings for stiffened cylinders. In particular, buckling-critical cylinders with integrally machined stiffener construction can benefit from the use of thicker plate material that enables taller stiffeners, even when the stiffness, strength and density properties of these materials appear to be inferior.

  15. Evolutionary Design of a Robotic Material Defect Detection System

    NASA Technical Reports Server (NTRS)

    Ballard, Gary; Howsman, Tom; Craft, Mike; ONeil, Daniel; Steincamp, Jim; Howell, Joe T. (Technical Monitor)

    2002-01-01

    During the post-flight inspection of SSME engines, several inaccessible regions must be disassembled to inspect for defects such as cracks, scratches, gouges, etc. An improvement to the inspection process would be the design and development of very small robots capable of penetrating these inaccessible regions and detecting the defects. The goal of this research was to utilize an evolutionary design approach for the robotic detection of these types of defects. A simulation and visualization tool was developed prior to receiving the hardware as a development test bed. A small, commercial off-the-shelf (COTS) robot was selected from several candidates as the proof of concept robot. The basic approach to detect the defects was to utilize Cadmium Sulfide (CdS) sensors to detect changes in contrast of an illuminated surface. A neural network, optimally designed utilizing a genetic algorithm, was employed to detect the presence of the defects (cracks). By utilization of the COTS robot and US sensors, the research successfully demonstrated that an evolutionarily designed neural network can detect the presence of surface defects.

  16. Design of a scientific probe for obtaining Mars surface material

    NASA Technical Reports Server (NTRS)

    Baker, Miles; Deyerl, Eric; Gibson, Tim; Langberg, Bob; Yee, Terrance (editor)

    1990-01-01

    The objective is to return a 1 Kg Martian soil sample from the surface of Mars to a mothership in a 60 km Mars orbit. Given here is information on the mission profile, the structural design and component placement, thermal control and guidance, propulsion systems, orbital mechanics, and specialized structures.

  17. Packaging Materials and Design for Improved PV Module Reliability

    SciTech Connect

    Jorgensen, G.; Terwilliger, K.; Kempe, M.; Pern, J.; Glick, S.; del Cueto, J.; Kennedy, C.; McMahon, T.

    2005-01-01

    A number of candidate alternative encapsulant and soft backsheet materials have been evaluated in terms of their suitability for photovoltaic (PV) module packaging applications. Relevant properties, including peel strength as a function of damp heat exposure and permeability, have been measured. Based on these tests, promising new encapsulants with adhesion-promoting primers have been identified that result in improved properties. Test results for backsheets provided by industry and prepared at the National Renewable Energy Laboratory (NREL) have suggested strategies to achieve significantly improved products. The ability of glass/glass and glass/breathable backsheet constructions laminated with various encapsulant and/or edge seal materials to protect thin-film aluminum coatings deposited onto glass substrates was assessed. Glass/glass laminate constructions can trap harmful compounds that catalyze moisture-driven corrosion of the aluminum. Constructions with breathable backsheets allow higher rates of moisture ingress, but also allow egress of deleterious substances that can result in decreased corrosion.

  18. Laboratory experiments designed to test the remediation properties of materials

    SciTech Connect

    Gilbert, J.S.; Wildeman, T.R.; Ford, K.L.

    1999-07-01

    Passive treatment systems constructed to remediate mine drainage have proven to be very successful for a wide variety of drainage compositions and volumes. The construction of an anaerobic passive treatment system requires a mixture of local materials with the objective of producing a system that allows adequate water flow while supporting the growth of sulfate-reducing bacteria. These bacteria have the effect of reducing the oxidizing potential in the system causing many sulfide-forming metals in solution to precipitate. The focus of these experiments was the study of chemical characteristics of materials, individually and in mixtures, with the purpose of determining which would be best suited for incorporation into a treatment system. The materials of interest were manure (fresh and aged), alfalfa, limestone, and sawdust, which were all collected in close proximity to the construction site of the proposed treatment system. A variety of chemical and physical hypotheses were formulated prior to performing simple chemical characterization and anaerobic treatment tests. The hypotheses relating to the chemical nature of the single materials were carbon to nitrogen ratio, availability of low molecular weight organic acids, number of adsorption sites, and organic carbon content. In addition, hypotheses concerning the performance of mixtures were evaluated by looking at the relative amount of bacterial growth (and metal removal) seen in each mixture over a 4-week period. The results of the laboratory experiments confirmed hypotheses, and demonstrated that in the mixtures, the anaerobic bacteria flourish when alfalfa is present, up to a point. The best mixture that allowed proliferation of bacteria while also removing metals consisted of 50% limestone, 25% aged manure, 15% sawdust, and 10% alfalfa (% by weight).

  19. First Materials Science Research Facility Rack Capabilities and Design Features

    NASA Technical Reports Server (NTRS)

    Cobb, S.; Higgins, D.; Kitchens, L.; Curreri, Peter (Technical Monitor)

    2002-01-01

    The first Materials Science Research Rack (MSRR-1) is the primary facility for U.S. sponsored materials science research on the International Space Station. MSRR-1 is contained in an International Standard Payload Rack (ISPR) equipped with the Active Rack Isolation System (ARIS) for the best possible microgravity environment. MSRR-1 will accommodate dual Experiment Modules and provide simultaneous on-orbit processing operations capability. The first Experiment Module for the MSRR-1, the Materials Science Laboratory (MSL), is an international cooperative activity between NASA's Marshall Space Flight Center (MSFC) and the European Space Agency's (ESA) European Space Research and Technology Center (ESTEC). The MSL Experiment Module will accommodate several on-orbit exchangeable experiment-specific Module Inserts which provide distinct thermal processing capabilities. Module Inserts currently planned for the MSL are a Quench Module Insert, Low Gradient Furnace, and a Solidification with Quench Furnace. The second Experiment Module for the MSRR-1 configuration is a commercial device supplied by MSFC's Space Products Development (SPD) Group. Transparent furnace assemblies include capabilities for vapor transport processes and annealing of glass fiber preforms. This Experiment Module is replaceable on-orbit. This paper will describe facility capabilities, schedule to flight and research opportunities.

  20. Digital Alchemy for Materials Design: Colloids and Beyond.

    PubMed

    van Anders, Greg; Klotsa, Daphne; Karas, Andrew S; Dodd, Paul M; Glotzer, Sharon C

    2015-10-27

    Starting with the early alchemists, a holy grail of science has been to make desired materials by modifying the attributes of basic building blocks. Building blocks that show promise for assembling new complex materials can be synthesized at the nanoscale with attributes that would astonish the ancient alchemists in their versatility. However, this versatility means that making a direct connection between building-block attributes and bulk structure is both necessary for rationally engineering materials and difficult because building block attributes can be altered in many ways. Here we show how to exploit the malleability of the valence of colloidal nanoparticle "elements" to directly and quantitatively link building-block attributes to bulk structure through a statistical thermodynamic framework we term "digital alchemy". We use this framework to optimize building blocks for a given target structure and to determine which building-block attributes are most important to control for self-assembly, through a set of novel thermodynamic response functions, moduli, and susceptibilities. We thereby establish direct links between the attributes of colloidal building blocks and the bulk structures they form. Moreover, our results give concrete solutions to the more general conceptual challenge of optimizing emergent behaviors in nature and can be applied to other types of matter. As examples, we apply digital alchemy to systems of truncated tetrahedra, rhombic dodecahedra, and isotropically interacting spheres that self-assemble diamond, fcc, and icosahedral quasicrystal structures, respectively. Although our focus is on colloidal systems, our methods generalize to any building blocks with adjustable interactions. PMID:26401754

  1. Regulatory compliance in the design of packages used to transport radioactive materials

    SciTech Connect

    Raske, D.T.

    1993-06-01

    Shipments of radioactive materials within the regulatory jurisdiction of the US Department of Energy (DOE) must meet the package design requirements contained in Title 10 of the Code of Federal Regulations, Part 71, and DOE Order 5480.3. These regulations do not provide design criteria requirements, but only detail the approval standards, structural performance criteria, and package integrity requirements that must be met during transport. The DOE recommended design criterion for high-level Category I radioactive packagings is Section III, Division 1, of the ASME Boiler and Pressure Vessel Code. However, alternative design criteria may be used if all the design requirements are satisfied. The purpose of this paper is to review alternatives to the Code criteria and discuss their applicability to the design of containment vessels in packages for high-level radioactive materials. Issues such as design qualification by physical testing, the use of scale models, and problems encountered using a non-ASME design approach are addressed.

  2. Ranking the Stars: A Refined Pareto Approach to Computational Materials Design

    NASA Astrophysics Data System (ADS)

    Lejaeghere, Kurt; Cottenier, Stefaan; Van Speybroeck, Veronique

    2013-08-01

    We propose a procedure to rank the most interesting solutions from high-throughput materials design studies. Such a tool is becoming indispensable due to the growing size of computational screening studies and the large number of criteria involved in realistic materials design. As a proof of principle, the binary tungsten alloys are screened for both large-weight and high-impact materials, as well as for fusion reactor applications. Moreover, the concept is generally applicable to any design problem where multiple competing criteria have to be optimized.

  3. Ranking the stars: a refined Pareto approach to computational materials design.

    PubMed

    Lejaeghere, Kurt; Cottenier, Stefaan; Van Speybroeck, Veronique

    2013-08-16

    We propose a procedure to rank the most interesting solutions from high-throughput materials design studies. Such a tool is becoming indispensable due to the growing size of computational screening studies and the large number of criteria involved in realistic materials design. As a proof of principle, the binary tungsten alloys are screened for both large-weight and high-impact materials, as well as for fusion reactor applications. Moreover, the concept is generally applicable to any design problem where multiple competing criteria have to be optimized. PMID:23992074

  4. Design and fabrication of far ultraviolet filters based on ?-multilayer technology in high-k materials

    PubMed Central

    Wang, Xiao-Dong; Chen, Bo; Wang, Hai-Feng; He, Fei; Zheng, Xin; He, Ling-Ping; Chen, Bin; Liu, Shi-Jie; Cui, Zhong-Xu; Yang, Xiao-Hu; Li, Yun-Peng

    2015-01-01

    Application of ?-multilayer technology is extended to high extinction coefficient materials, which is introduced into metal-dielectric filter design. Metal materials often have high extinction coefficients in far ultraviolet (FUV) region, so optical thickness of metal materials should be smaller than that of the dielectric material. A broadband FUV filter of 9-layer non-periodic Al/MgF2 multilayer was successfully designed and fabricated and it shows high reflectance in 140–180?nm, suppressed reflectance in 120–137?nm and 181–220?nm. PMID:25687255

  5. Virtual Welded - Joint Design Integrating Advanced Materials and Processing Technology

    SciTech Connect

    Yang, Zhishang; Ludewig, Howard W.; Babu, S. Suresh

    2005-06-30

    Virtual Welede-Joint Design, a systematic modeling approach, has been developed in this project to predict the relationship of welding process, microstructure, properties, residual stress, and the ultimate weld fatique strength. This systematic modeling approach was applied in the welding of high strength steel. A special welding wire was developed in this project to introduce compressive residual stress at weld toe. The results from both modeling and experiments demonstrated that more than 10x fatique life improvement can be acheived in high strength steel welds by the combination of compressive residual stress from the special welding wire and the desired weld bead shape from a unique welding process. The results indicate a technology breakthrough in the design of lightweight and high fatique performance welded structures using high strength steels.

  6. Design of responsive materials using topologically interlocked elements

    NASA Astrophysics Data System (ADS)

    Molotnikov, A.; Gerbrand, R.; Qi, Y.; Simon, G. P.; Estrin, Y.

    2015-02-01

    In this work we present a novel approach to designing responsive structures by segmentation of monolithic plates into an assembly of topologically interlocked building blocks. The particular example considered is an assembly of interlocking osteomorphic blocks. The results of this study demonstrate that the constraining force, which is required to hold the blocks together, can be viewed as a design parameter that governs the bending stiffness and the load bearing capacity of the segmented structure. In the case where the constraining forces are provided laterally using an external frame, the maximum load the assembly can sustain and its stiffness increase linearly with the magnitude of the lateral load applied. Furthermore, we show that the segmented plate with integrated shape memory wires employed as tensioning cables can act as a smart structure that changes its flexural stiffness and load bearing capacity in response to external stimuli, such as heat generated by the switching on and off an electric current.

  7. Decoupling interrelated parameters for designing high performance thermoelectric materials.

    PubMed

    Xiao, Chong; Li, Zhou; Li, Kun; Huang, Pengcheng; Xie, Yi

    2014-04-15

    The world's supply of fossil fuels is quickly being exhausted, and the impact of their overuse is contributing to both climate change and global political unrest. In order to help solve these escalating problems, scientists must find a way to either replace combustion engines or reduce their use. Thermoelectric materials have attracted widespread research interest because of their potential applications as clean and renewable energy sources. They are reliable, lightweight, robust, and environmentally friendly and can reversibly convert between heat and electricity. However, after decades of development, the energy conversion efficiency of thermoelectric devices has been hovering around 10%. This is far below the theoretical predictions, mainly due to the interdependence and coupling between electrical and thermal parameters, which are strongly interrelated through the electronic structure of the materials. Therefore, any strategy that balances or decouples these parameters, in addition to optimizing the materials' intrinsic electronic structure, should be critical to the development of thermoelectric technology. In this Account, we discuss our recently developed strategies to decouple thermoelectric parameters for the synergistic optimization of electrical and thermal transport. We first highlight the phase transition, which is accompanied by an abrupt change of electrical transport, such as with a metal-insulator and semiconductor-superionic conductor transition. This should be a universal and effective strategy to optimize the thermoelectric performance, which takes advantage of modulated electronic structure and critical scattering across phase transitions to decouple the power factor and thermal conductivity. We propose that solid-solution homojunction nanoplates with disordered lattices are promising thermoelectric materials to meet the "phonon glass electron crystal" approach. The formation of a solid solution, coupled with homojunctions, allows for synergistically enhanced thermoelectric properties. This occurs through a significant reduction of thermal conductivity, without the deterioration of thermopower and electrical conductivity. In addition, we introduce the concept of spin entropy in wide band gap semiconductor nanocrystals, which acts to fully disentangle the otherwise interconnected quantities for synergistically optimized thermoelectric performance. Finally, we discuss a new concept we developed that is based on an ultrathin-nanosheet composite that we fabricated from ultrathin nanosheets of atomic thickness. These retain the original strong two-dimensional electron gas (2DEG) and allow for decoupled optimization of the three thermoelectric parameters, which improves thermoelectric performance. PMID:24517646

  8. Photovoltaic Module Encapsulation Design and Materials Selection, Volume 1, Abridged

    NASA Technical Reports Server (NTRS)

    Cuddihy, E. F.

    1982-01-01

    A summary version of Volume 1, presenting the basic encapsulation systems, their purposes and requirements, and the characteristics of the most promising candidate systems and materials, as identified and evaluated by the Flat-Plate Solar Array Project is presented. In this summary version considerable detail and much supporting and experimental information has necessarily been omitted. A reader interested in references and literature citations, and in more detailed information on specific topics, should consult Reference 1, JPL Document No. 5101-177, JPL Publication 81-102, DOE/JPL-1012-60 (JPL), June 1, 1982.

  9. Negative index of refraction in optical metamaterials

    NASA Astrophysics Data System (ADS)

    Shalaev, Vladimir M.; Cai, Wenshan; Chettiar, Uday K.; Yuan, Hsiao-Kuan; Sarychev, Andrey K.; Drachev, Vladimir P.; Kildishev, Alexander V.

    2005-12-01

    A double-periodic array of pairs of parallel gold nanorods is shown to have a negative refractive index in the optical range. Such behavior results from the plasmon resonance in the pairs of nanorods for both the electric and the magnetic components of light. The refractive index is retrieved from direct phase and amplitude measurements for transmission and reflection, which are all in excellent agreement with simulations. Both experiments and simulations demonstrate that a negative refractive index n??-0.3 is achieved at the optical communication wavelength of 1.5 µm using the array of nanorods. The retrieved refractive index critically depends on the phase of the transmitted wave, which emphasizes the importance of phase measurements in finding n?.

  10. Opportunities and challenges for first-principles materials design and applications to Li battery materials

    E-print Network

    Ceder, Gerbrand

    The idea of first-principles methods is to determine the properties of materials by solving the basic equations of quantum mechanics and statistical mechanics. With such an approach, one can, in principle, predict the ...

  11. Rational Design of Molecular Ferroelectric Materials and Nanostructures

    SciTech Connect

    Ducharme, Stephen

    2012-09-25

    The purpose of this project was to gain insight into the properties of molecular ferroelectrics through the detailed study of oligomer analogs of polyvinylidene fluoride (PVDF). By focusing on interactions at both the molecular level and the nanoscale level, we expect to gain improved understanding about the fundamental mechanism of ferroelectricity and its key properties. The research consisted of three complementary components: 1) Rational synthesis of VDF oligomers by Prof. Takacs���¢�������� group; 2) Detailed structural and electrical studies of thin by Prof. Ducharme���¢��������s Group; and 3) First-principles computational studies by DOE Lab Partner Dr. Serge Nakhman-son at Argonne National Laboratory. The main results of the work was a detailed understanding of the relationships between the molecular interactions and macroscopic phenomenology of fer-roelectricity VDF oligomers. This is valuable information supporting the development of im-proved electromechanical materials for, e.g., sonar, ultrasonic imaging, artificial muscles, and compliant actuators. Other potential applications include nonvolatile ferroelectric memories, heat-sensing imaging arrays, photovoltaic devices, and functional biomimetic materials. The pro-ject contributed to the training and professional development of undergraduate students and graduate students, post-doctoral assistants, and a high-school teacher. Project personnel took part in several outreach and education activities each year.

  12. Design of electronics for a high-resolution, multi-material, and modular 3D printer

    E-print Network

    Kwan, Joyce G

    2013-01-01

    Electronics for a high-resolution, multi-material, and modular 3D printer were designed and implemented. The driver for a piezoelectric inkjet print head can fire its nozzles with one of three droplet sizes ranging from 6 ...

  13. Design of new frictional testing machine for shallow fault materials

    NASA Astrophysics Data System (ADS)

    Tadai, O.; Tanikawa, W.; Hirose, T.; Sakaguchi, M.; Lin, W.

    2009-12-01

    Subduction thrust faults at shallow depth mainly consist of granular and clay-rich materials which strengths are influenced by the presence of pore water. Dilatation and pore pressure generation of fault zones by the dynamic friction will increase the volumetric water content in fault zone, which can assist the fault weakening by acoustic fluidization or hydrodynamic lubrication mechanism. Therefore the evaluation of rheology for clay minerals rich in pore water is critical for understanding of seismic behaviors at shallow depth. Here, we introduce a new testing apparatus for the purpose of accurate evaluation of friction behavior for incohesive fault rock materials. Our machine can shear granular materials up to 80 mm of outer diameter and maximum thickness of 40 mm. The capacities of axial load, torque, and motor are 100kN, 500Nm and 30kW, respectively, and pore pressure is increased up to 50 MPa. Maximum rotation speed is 660 rpm, which is equivalent to 1 m/s of the average slip velocity when sample diameter is 60 mm. We can monitor the dynamic changes of pore pressure and temperature at sliding surface during the friction tests. We can also control the pore pressure, axial load, pore pressure and temperature independently. All parameters can be held at targeted values and be generated at constant incremental velocity. We can control the rotation more sensitively to program the complicated rotation history that slip velocity and acceleration change during the rotation. We used powdered smectite and illite in our friction tests. We measured normal stress dependence on shear stress at normal stress up to 25 MPa with a constant rotation speed from 0.01 to 1 rpm. Normal stress is proportional to shear stress for dry clay minerals, and the friction coefficients are from 0.3 to 0.5. On the other hand, very low friction is observed in clay minerals saturated by water, and shear strength is nearly constant at various normal stresses. Our results suggest that clay minerals will lose their strength when clay minerals contain water at a certain ratio, and clay minerals behave as viscous fluid. The transition process from Amonton’s law of friction to viscous flow is important for understanding of friction behavior at shallow depth. (a) Frictional strength for a variety of rocks plotted as a function of normal stress. (b) Enlargement of figure (a) at a low stress regime.

  14. Molecular Designs for Enhancement of Polarity in Ferroelectric Soft Materials.

    PubMed

    Ohtani, Ryo; Nakaya, Manabu; Ohmagari, Hitomi; Nakamura, Masaaki; Ohta, Kazuchika; Lindoy, Leonard F; Hayami, Shinya

    2015-01-01

    The racemic oxovanadium(IV) salmmen complexes, [VO((rac)-(4-X-salmmen))] (X?=?C12C10C5 (1), C16 (2), and C18 (3); salmmen?=?N,N'-monomethylenebis-salicylideneimine) with "banana shaped" molecular structures were synthesized, and their ferroelectric properties were investigated. These complexes exhibit well-defined hysteresis loops in their viscous phases, moreover, 1 also displays liquid crystal behaviour. We observed a synergetic effect influenced by three structural aspects; the methyl substituents on the ethylene backbone, the banana shaped structure and the square pyramidal metal cores all play an important role in generating the observed ferroelectricity, pointing the way to a useful strategy for the creation of advanced ferroelectric soft materials. PMID:26568045

  15. Molecular Designs for Enhancement of Polarity in Ferroelectric Soft Materials

    PubMed Central

    Ohtani, Ryo; Nakaya, Manabu; Ohmagari, Hitomi; Nakamura, Masaaki; Ohta, Kazuchika; Lindoy, Leonard F.; Hayami, Shinya

    2015-01-01

    The racemic oxovanadium(IV) salmmen complexes, [VO((rac)-(4-X-salmmen))] (X?=?C12C10C5 (1), C16 (2), and C18 (3); salmmen?=?N,N?-monomethylenebis-salicylideneimine) with “banana shaped” molecular structures were synthesized, and their ferroelectric properties were investigated. These complexes exhibit well-defined hysteresis loops in their viscous phases, moreover, 1 also displays liquid crystal behaviour. We observed a synergetic effect influenced by three structural aspects; the methyl substituents on the ethylene backbone, the banana shaped structure and the square pyramidal metal cores all play an important role in generating the observed ferroelectricity, pointing the way to a useful strategy for the creation of advanced ferroelectric soft materials. PMID:26568045

  16. Molecular Designs for Enhancement of Polarity in Ferroelectric Soft Materials

    NASA Astrophysics Data System (ADS)

    Ohtani, Ryo; Nakaya, Manabu; Ohmagari, Hitomi; Nakamura, Masaaki; Ohta, Kazuchika; Lindoy, Leonard F.; Hayami, Shinya

    2015-11-01

    The racemic oxovanadium(IV) salmmen complexes, [VO((rac)-(4-X-salmmen))] (X?=?C12C10C5 (1), C16 (2), and C18 (3); salmmen?=?N,N?-monomethylenebis-salicylideneimine) with “banana shaped” molecular structures were synthesized, and their ferroelectric properties were investigated. These complexes exhibit well-defined hysteresis loops in their viscous phases, moreover, 1 also displays liquid crystal behaviour. We observed a synergetic effect influenced by three structural aspects; the methyl substituents on the ethylene backbone, the banana shaped structure and the square pyramidal metal cores all play an important role in generating the observed ferroelectricity, pointing the way to a useful strategy for the creation of advanced ferroelectric soft materials.

  17. Design of biocomposite materials for bone tissue regeneration.

    PubMed

    Yunus Basha, Rubaiya; Sampath Kumar, T S; Doble, Mukesh

    2015-12-01

    Several synthetic scaffolds are being developed using polymers, ceramics and their composites to overcome the limitations of auto- and allografts. Polymer-ceramic composites appear to be the most promising bone graft substitute since the natural bone itself is a composite of collagen and hydroxyapatite. Ceramics provide strength and osteoconductivity to the scaffold while polymers impart flexibility and resorbability. Natural polymers have an edge over synthetic polymers because of their biocompatibility and biological recognition property. But, very few natural polymer-ceramic composites are available as commercial products, and those few are predominantly based on type I collagen. Disadvantages of using collagen include allergic reactions and pathogen transmission. The commercial products also lack sufficient mechanical properties. This review summarizes the recent developments of biocomposite materials as bone scaffolds to overcome these drawbacks. Their characteristics, in vitro and in vivo performance are discussed with emphasis on their mechanical properties and ways to improve their performance. PMID:26354284

  18. Development of Digital Materials Database for Design and Construction of New Power Plants

    SciTech Connect

    Ren, Weiju

    2008-01-01

    To facilitate materials selection, structural design, and future maintenance of the Generation IV nuclear reactor systems, an interactive, internet accessible materials property database, dubbed Gen IV Materials Handbook, has been under development with the support of the United States Department of Energy. The Handbook will provide an authoritative source of information on structural materials needed for the development of various Gen IV nuclear reactor systems along with powerful data analysis and management tools. In this paper, the background, history, framework, major features, contents, and development strategy of the Gen IV Materials Handbook are discussed. Current development status and future plans are also elucidated.

  19. Design finalization and material qualification towards procurement of the ITER vacuum vessel

    NASA Astrophysics Data System (ADS)

    Ioki, K.; Barabash, V.; Bachmann, C.; Chappuis, P.; Choi, C. H.; Cordier, J.-J.; Giraud, B.; Gribov, Y.; Heitzenroeder, Ph.; Her, N.; Johnson, G.; Jones, L.; Jun, C.; Kim, B. C.; Kuzmin, E.; Loesser, D.; Martin, A.; Merola, M.; Pathak, H.; Readman, P.; Sugihara, M.; Terasawa, A.; Utin, Yu.; Wang, X.; Wu, S.; Yu, J.; ITER Organization; ITER Parties

    2011-10-01

    Procurement arrangements for ITER key components including the vacuum vessel (VV) have been signed and the ITER activities are now fully devoted towards construction. Final design reviews have been carried out for the main vessel and ports. One of the design review topics is the selection of materials, material procurement, and assessment of material performance during operation. The width of the inner shell splice plates was increased from 120 mm to 160 mm to minimize risk during the assembly of the Thermal shields and the VV. Instead of facet shaping, 3D shaping was introduced for the outboard inner shell. The material qualification procedures have been started for VV structural materials such as 316L(N) IG for licensing as a nuclear pressure equipment component. In accordance with the regulatory requirements and quality requirements for operation, common material specifications have been prepared in collaboration with the domestic agencies.

  20. An advanced microcomputer design for processing of semiconductor materials

    NASA Technical Reports Server (NTRS)

    Bjoern, L.; Lindkvist, L.; Zaar, J.

    1988-01-01

    In the Get Away Special 330 payload two germanium samples doped with gallium will be processed. The aim of the experiments is to create a planar solid/liquid interface, and to study the breakdown of this interface as the crystal growth rate increases. For the experiments a gradient furnace was designed which is heated by resistive heaters. Cooling is provided by circulating gas from the atmosphere in the cannister through cooling channels in the furnace. The temperature along the sample are measured by platinum/rhodium thermocouples. The furnace is controlled by a microcomputer system, based upon the processor 80C88. A data acquisition system is integrated into the system. In order to synchronize the different actions in time, a multitask manager is used.

  1. Ionomer Design Principles for Single Ion-Conducting Energy Materials

    NASA Astrophysics Data System (ADS)

    Colby, Ralph; Liang, Siwei; Liu, Wenjuan; Hyeok Choi, U.; Runt, James; Shiau, Huai-Suen; Janik, Michael

    2012-02-01

    Single-ion conducting ionomers with low glass transition temperature, high dielectric constant and containing bulky ions with diffuse charge, are needed for polymer membranes that transport small counterions. Overarching design principles emerging from quantum chemistry calculations suggest that diffuse charge can be attained from simple considerations of atomic electronegativity. For lithium or sodium batteries, perfluorinated tetraphenyl borate ionomers with solvating polar comonomers are proposed. For fluoride or hydroxide batteries and for iodide transporting solar cells, tetra-alkyl phosphonium ionomers with anion receptors are proposed. First attempts to construct such ionomers to test these ideas will be discussed, with results from dielectric spectroscopy to measure conductivity, dielectric constant and number density of simultaneously conducting ions.

  2. Material property for designing, analyzing, and fabricating space structures

    NASA Technical Reports Server (NTRS)

    Kolkailah, Faysal A.

    1991-01-01

    An analytical study was made of plasma assisted bullet projectile. The finite element analysis and the micro-macromechanic analysis was applied to an optimum design technique for the multilayered graphite-epoxy composite projectile that will achieve hypervelocity of 6 to 10 Km/s. The feasibility was determined of dialectics to monitor cure of graphite-epoxies. Several panels were fabricated, cured, and tested with encouraging results of monitoring the cure of graphite-epoxies. The optimum cure process for large structures was determined. Different orientation were used and three different curing cycles were employed. A uniaxial tensile test was performed on all specimens. The optimum orientation with the optimum cure cycle were concluded.

  3. The Use of Schema Theory in the Design of Instructional Materials: A Physics Example.

    ERIC Educational Resources Information Center

    Hewson, Peter, W.; Posner, George J.

    1984-01-01

    Describes development of a generative schema based on the concept of change for inclusion in instructional materials for a college physics course to help students integrate all of the physics content. Psychological basis for these materials is discussed, a design approach is described, and questions are posed for further investigation. (MBR)

  4. Curriculum Design for Inquiry: Preservice Elementary Teachers' Mobilization and Adaptation of Science Curriculum Materials

    ERIC Educational Resources Information Center

    Forbes, Cory T.; Davis, Elizabeth A.

    2010-01-01

    Curriculum materials are crucial tools with which teachers engage students in science as inquiry. In order to use curriculum materials effectively, however, teachers must develop a robust capacity for pedagogical design, or the ability to mobilize a variety of personal and curricular resources to promote student learning. The purpose of this study…

  5. Material Characterization of Fused Deposition Modeling (FDM) ABS by Designed Experiments

    E-print Network

    Simpkins, Alex

    1 Material Characterization of Fused Deposition Modeling (FDM) ABS by Designed Experiments Michael Prototyping (RP) technology has been advanced to fabricate initial prototypes from various materials. Stratasys' Fused Deposition Modeling (FDM) is one of the typical RP processes that provide functional

  6. PCB Origami: A Material-Based Design Approach to Computer-Aided Foldable Electronic Devices

    E-print Network

    Demaine, Erik

    PCB Origami: A Material-Based Design Approach to Computer-Aided Foldable Electronic Devices Yoav of material with embedded electronics such as PCB (Printed Circuit Boards) as the medium for origami folding functionalities. PCBs are produced as 2D shapes. By folding PCB arrays it is possible to create 3D objects

  7. 46 CFR 128.240 - Hydraulic or pneumatic power and control-materials and pressure design.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Hydraulic or pneumatic power and control-materials and... Hydraulic or pneumatic power and control—materials and pressure design. (a) Each standard piping component (such as pipe runs, fittings, flanges, and standard valves) for hydraulic or pneumatic power and...

  8. 46 CFR 128.240 - Hydraulic or pneumatic power and control-materials and pressure design.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Hydraulic or pneumatic power and control-materials and... Hydraulic or pneumatic power and control—materials and pressure design. (a) Each standard piping component (such as pipe runs, fittings, flanges, and standard valves) for hydraulic or pneumatic power and...

  9. 46 CFR 128.240 - Hydraulic or pneumatic power and control-materials and pressure design.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Hydraulic or pneumatic power and control-materials and... Hydraulic or pneumatic power and control—materials and pressure design. (a) Each standard piping component (such as pipe runs, fittings, flanges, and standard valves) for hydraulic or pneumatic power and...

  10. 46 CFR 128.240 - Hydraulic or pneumatic power and control-materials and pressure design.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Hydraulic or pneumatic power and control-materials and... Hydraulic or pneumatic power and control—materials and pressure design. (a) Each standard piping component (such as pipe runs, fittings, flanges, and standard valves) for hydraulic or pneumatic power and...

  11. 46 CFR 160.077-7 - Procedure for approval of design or material revision.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Procedure for approval of design or material revision. 160.077-7 Section 160.077-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Hybrid...

  12. A data mining approach to forming generic bills of materials in support of variant design activities

    E-print Network

    Nagi, Rakesh

    1 A data mining approach to forming generic bills of materials in support of variant design. This research presents a novel, data mining approach to forming generic bills of materials (GBOMs), entities through data mining methods such as text and tree mining, a new tree union procedure, and embodying

  13. 46 CFR 128.240 - Hydraulic or pneumatic power and control-materials and pressure design.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Hydraulic or pneumatic power and control-materials and... Hydraulic or pneumatic power and control—materials and pressure design. (a) Each standard piping component (such as pipe runs, fittings, flanges, and standard valves) for hydraulic or pneumatic power and...

  14. Materials issues in the design of the ITER first wall, blanket, and divertor

    SciTech Connect

    Mattas, R.F.; Smith, D.L. ); Wu, C.H. . NET Team); Koroda, T. ); Shatalov, G. )

    1992-01-01

    During the ITER conceptual design study, a property data base was assembled, the key issues were identified, and a comprehensive R D plan was formulated to resolve these issues. The desired properties of candidate ITER divertor, first wall, and blanket materials are briefly reviewed, and the major materials issues are presented. Estimates of the influence of materials properties on the performance limits of the first wall, blanket, and divertor are presented.

  15. Materials issues in the design of the ITER first wall, blanket, and divertor

    SciTech Connect

    Mattas, R.F.; Smith, D.L.; Wu, C.H.; Koroda, T.; Shatalov, G.

    1992-01-01

    During the ITER conceptual design study, a property data base was assembled, the key issues were identified, and a comprehensive R&D plan was formulated to resolve these issues. The desired properties of candidate ITER divertor, first wall, and blanket materials are briefly reviewed, and the major materials issues are presented. Estimates of the influence of materials properties on the performance limits of the first wall, blanket, and divertor are presented.

  16. 75 FR 19311 - Ocean Dumping; Guam Ocean Dredged Material Disposal Site Designation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-14

    ...The EPA is proposing to designate the Guam Deep Ocean Disposal Site (G-DODS) as a permanent ocean dredged material disposal site (ODMDS) located offshore of Guam. Dredging is essential for maintaining safe navigation at port and naval facilities in Apra Harbor and other locations around Guam. Not all dredged materials are suitable for beneficial re-use (e.g., construction materials, landfill......

  17. Computational nano-materials design of high efficiency photovoltaic materials by spinodal nano-decomposition in Chalcopyrite-type semiconductors

    NASA Astrophysics Data System (ADS)

    Asahina, Hideo; Tani, Yoshimasa; Sato, Kazunori; Katayama-Yoshida, Hiroshi

    2014-03-01

    Chalcopyrite-type semiconductor CuInSe2 (CIS) is one of the most promising materials for low cost photovoltaic solar-cells due to its self-regeneration mechanism. However, from the point of resource security, high concentration of In in CIS is serious disadvantage. Recently, Cu2ZnSnS4 (CZTS) attracts much attention to overcome this disadvantage of CIS. This material has already been investigated as a photovoltaic material but the efficiency is not high enough. Based on the first-principles calculations by the KKR-CPA method, we propose how we can enhance the efficiency of CZTS by utilizing the self-organization phenomena caused by spinodal nano-decomposition of Cu & Cu-vacancy, S & Se, and Se & Oxygen. We will compare our design with the available experimental data of STEM-EDX, EELS, Atom Probe Tomography and Raman Scattering data. In addition to the above materials design, we also discuss intermediate band type solar-cells caused by the spinodal nano-decomposition, and propose Fe-doped CuFeS2-CuAlS2 (CFS-CAS), CuFeS2-CuGaS2 (CFS-CGS) and CuFeS2-CuInS2 (CFS-CIS) as promising materials with enhanced conversion efficiency up to 50%.

  18. Life Modeling and Design Analysis for Ceramic Matrix Composite Materials

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The primary research efforts focused on characterizing and modeling static failure, environmental durability, and creep-rupture behavior of two classes of ceramic matrix composites (CMC), silicon carbide fibers in a silicon carbide matrix (SiC/SiC) and carbon fibers in a silicon carbide matrix (C/SiC). An engineering life prediction model (Probabilistic Residual Strength model) has been developed specifically for CMCs. The model uses residual strength as the damage metric for evaluating remaining life and is posed probabilistically in order to account for the stochastic nature of the material s response. In support of the modeling effort, extensive testing of C/SiC in partial pressures of oxygen has been performed. This includes creep testing, tensile testing, half life and residual tensile strength testing. C/SiC is proposed for airframe and propulsion applications in advanced reusable launch vehicles. Figures 1 and 2 illustrate the models predictive capabilities as well as the manner in which experimental tests are being selected in such a manner as to ensure sufficient data is available to aid in model validation.

  19. Materials modeling by design: applications to amorphous solids

    NASA Astrophysics Data System (ADS)

    Biswas, Parthapratim; Tafen, D. N.; Inam, F.; Cai, Bin; Drabold, D. A.

    2009-02-01

    In this paper, we review a host of methods used to model amorphous materials. We particularly describe methods which impose constraints on the models to ensure that the final model meets a priori requirements (on structure, topology, chemical order, etc). In particular, we review work based on quench from the melt simulations, the 'decorate and relax' method, which is shown to be a reliable scheme for forming models of certain binary glasses. A 'building block' approach is also suggested and yields a pleading model for GeSe1.5. We also report on the nature of vulcanization in an Se network cross-linked by As, and indicate how introducing H into an a-Si network develops into a-Si:H. We also discuss explicitly constrained methods including reverse Monte Carlo (RMC) and a novel method called 'Experimentally Constrained Molecular Relaxation'. The latter merges the power of ab initio simulation with the ability to impose external information associated with RMC.

  20. Materials modeling by design: applications to amorphous solids.

    PubMed

    Biswas, Parthapratim; Tafen, D N; Inam, F; Cai, Bin; Drabold, D A

    2009-02-25

    In this paper, we review a host of methods used to model amorphous materials. We particularly describe methods which impose constraints on the models to ensure that the final model meets a priori requirements (on structure, topology, chemical order, etc). In particular, we review work based on quench from the melt simulations, the 'decorate and relax' method, which is shown to be a reliable scheme for forming models of certain binary glasses. A 'building block' approach is also suggested and yields a pleading model for GeSe(1.5). We also report on the nature of vulcanization in an Se network cross-linked by As, and indicate how introducing H into an a-Si network develops into a-Si:H. We also discuss explicitly constrained methods including reverse Monte Carlo (RMC) and a novel method called 'Experimentally Constrained Molecular Relaxation'. The latter merges the power of ab initio simulation with the ability to impose external information associated with RMC. PMID:21817359

  1. Design of a curvature sensor using a flexoelectric material

    NASA Astrophysics Data System (ADS)

    Yan, X.; Huang, W. B.; Kwon, S. R.; Yang, S. R.; Jiang, X. N.; Yuan, F. G.

    2013-04-01

    A curvature sensor based on flexoelectricity using Ba0.64Sr0.36TiO3 (BST) material is proposed and developed in this paper. The working principle of the sensor is based on the flexoelectricity, exhibiting coupling between mechanical strain gradient and electric polarization. A BST curvature sensor is lab prepared using a conventional solid state processing method. The curvature sensing is demonstrated in four point bending tests of the beam under harmonic loads. BST sensors are attached on both side surfaces of an aluminum beam, located symmetrically with respect to its neutral axis. Analyses have shown that the epoxy bonding layer plays a critical role for curvature transfer. Consequently a shear lag effect is taken into account for extracting actual curvature from the sensor measurement. Experimental results demonstrated good linearity from the charge outputs under the frequencies tests and showed a sensor sensitivity of 30.78pC•m in comparison with 32.48pC•m from theoretical prediction. The BST sensor provides a direct curvature measure instead of using traditional strain gage through interpolation and may offer an optional avenue for on-line and in-situ structural health monitoring.

  2. Representing Clarity: Using Universal Design Principles to Create Effective Hybrid Course Learning Materials

    ERIC Educational Resources Information Center

    Spiegel, Cheri Lemieux

    2012-01-01

    This article describes how the author applied principles of universal design to hybrid course materials to increase student understanding and, ultimately, success. Pulling the three principles of universal design--consistency, color, and icon representation--into the author's Blackboard course allowed her to change the types of reading skills…

  3. Materials by Design: Merging Proteins and Music Joyce Y. Wong1

    E-print Network

    Spivak, David

    1 Materials by Design: Merging Proteins and Music Joyce Y. Wong1 , John McDonald2 , Micki Taylor science and engineering are fundamental unifying factors that link a range of fields of immense fields in nanotechnology where a central challenge remains the coupling of scales in the design

  4. MD-05-1288. 1 Seepersad et al ROBUST DESIGN OF CELLULAR MATERIALS WITH

    E-print Network

    Seepersad, Carolyn Conner

    with customized elastic properties that are robust to dimensional tolerances and topological imperfections for multifunctional performance requirements. In this paper, the focus is on designing mesoscopic material topology properties that are superior to those of standard or heuristic designs, customized for large

  5. 30 CFR 36.20 - Quality of material, workmanship, and design.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Quality of material, workmanship, and design... TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS APPROVAL REQUIREMENTS FOR PERMISSIBLE MOBILE DIESEL-POWERED TRANSPORTATION EQUIPMENT Construction and Design Requirements § 36.20 Quality of...

  6. 30 CFR 36.20 - Quality of material, workmanship, and design.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Quality of material, workmanship, and design... TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS APPROVAL REQUIREMENTS FOR PERMISSIBLE MOBILE DIESEL-POWERED TRANSPORTATION EQUIPMENT Construction and Design Requirements § 36.20 Quality of...

  7. 30 CFR 36.20 - Quality of material, workmanship, and design.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Quality of material, workmanship, and design... TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS APPROVAL REQUIREMENTS FOR PERMISSIBLE MOBILE DIESEL-POWERED TRANSPORTATION EQUIPMENT Construction and Design Requirements § 36.20 Quality of...

  8. Facility and Material Handling Systems Design Instructor: Durward Sobek, 318 Roberts Hall, 994-7140

    E-print Network

    Sobek II, Durward K.

    , & Tanchoco, Facilities Planning, 4th edition, John Wiley & Sons, 2003. Catalog Description: 3 credits for planning and designing production facilities and material handling systems. Product and process analysis. articulate systematic procedures for facilities planning and the corresponding design steps; 2. analyze

  9. Materials study supporting thermochemical hydrogen cycle sulfuric acid decomposer design

    NASA Astrophysics Data System (ADS)

    Peck, Michael S.

    Increasing global climate change has been driven by greenhouse gases emissions originating from the combustion of fossil fuels. Clean burning hydrogen has the potential to replace much of the fossil fuels used today reducing the amount of greenhouse gases released into the atmosphere. The sulfur iodine and hybrid sulfur thermochemical cycles coupled with high temperature heat from advanced nuclear reactors have shown promise for economical large-scale hydrogen fuel stock production. Both of these cycles employ a step to decompose sulfuric acid to sulfur dioxide. This decomposition step occurs at high temperatures in the range of 825°C to 926°C dependent on the catalysis used. Successful commercial implementation of these technologies is dependent upon the development of suitable materials for use in the highly corrosive environments created by the decomposition products. Boron treated diamond film was a potential candidate for use in decomposer process equipment based on earlier studies concluding good oxidation resistance at elevated temperatures. However, little information was available relating the interactions of diamond and diamond films with sulfuric acid at temperatures greater than 350°C. A laboratory scale sulfuric acid decomposer simulator was constructed at the Nuclear Science and Engineering Institute at the University of Missouri-Columbia. The simulator was capable of producing the temperatures and corrosive environments that process equipment would be exposed to for industrialization of the sulfur iodide or hybrid sulfur thermochemical cycles. A series of boron treated synthetic diamonds were tested in the simulator to determine corrosion resistances and suitability for use in thermochemical process equipment. These studies were performed at twenty four hour durations at temperatures between 600°C to 926°C. Other materials, including natural diamond, synthetic diamond treated with titanium, silicon carbide, quartz, aluminum nitride, and Inconel were also tested in the simulator to determine corrosion resistances. The study concluded that boron treated diamonds were not suitable for use in decomposer process equipment. Unacceptable corrosion rates were observed at 600°C and increased linearly with temperature up to 700°C. The boron treated diamonds completely disassociated at temperatures above 700°C. The researcher postulated that the high corrosion rates resulted from diamond carbon having a higher preference for oxygen free radicals formed during the decomposition process. Oxygen free radical concentration also increased as a function of increasing temperature. The study also concluded that natural diamond and synthetic titanium treated diamond were unsuitable for use in decomposer process equipment. The corrosion results were similar to that of the boron treated diamonds. Silicon carbide may have potential for used in decomposer process equipment. No appreciable silicon carbide corrosion was observed and more study is warranted. Small amounts of quartz and aluminum nitride corrosion was observed. Inconel corrosion rates were very high at all temperatures tested.

  10. The Structures/Materials Program encompasses a multitude of areas such as structural analysis and design, steel and concrete structures,

    E-print Network

    , structural dynamics, composite materials, stress analysis, cement based materials, experimental methods etcThe Structures/Materials Program encompasses a multitude of areas such as structural analysis analysis and design, stability of structures, nonlinear structural analysis, structural failure

  11. Soft materials design via self assembly of functionalized icosahedral particles

    NASA Astrophysics Data System (ADS)

    Muthukumar, Vidyalakshmi Chockalingam

    In this work we simulate self assembly of icosahedral building blocks using a coarse grained model of the icosahedral capsid of virus 1m1c. With significant advancements in site-directed functionalization of these macromolecules [1], we propose possible application of such self-assembled materials for drug delivery. While there have been some reports on organization of viral particles in solution through functionalization, exploiting this behaviour for obtaining well-ordered stoichiometric structures has not yet been explored. Our work is in well agreement with the earlier simulation studies of icosahedral gold nanocrystals, giving chain like patterns [5] and also broadly in agreement with the wet lab works of Finn, M.G. et al., who have shown small predominantly chain-like aggregates with mannose-decorated Cowpea Mosaic Virus (CPMV) [22] and small two dimensional aggregates with oligonucleotide functionalization on the CPMV capsid [1]. To quantify the results of our Coarse Grained Molecular Dynamics Simulations I developed analysis routines in MATLAB using which we found the most preferable nearest neighbour distances (from the radial distribution function (RDF) calculations) for different lengths of the functional groups and under different implicit solvent conditions, and the most frequent coordination number for a virus particle (histogram plots further using the information from RDF). Visual inspection suggests that our results most likely span the low temperature limits explored in the works of Finn, M.G. et al., and show a good degree of agreement with the experimental results in [1] at an annealing temperature of 4°C. Our work also reveals the possibility of novel stoichiometric N-mer type aggregates which could be synthesized using these capsids with appropriate functionalization and solvent conditions.

  12. Big-deep-smart data in imaging for guiding materials design.

    PubMed

    Kalinin, Sergei V; Sumpter, Bobby G; Archibald, Richard K

    2015-10-01

    Harnessing big data, deep data, and smart data from state-of-the-art imaging might accelerate the design and realization of advanced functional materials. Here we discuss new opportunities in materials design enabled by the availability of big data in imaging and data analytics approaches, including their limitations, in material systems of practical interest. We specifically focus on how these tools might help realize new discoveries in a timely manner. Such methodologies are particularly appropriate to explore in light of continued improvements in atomistic imaging, modelling and data analytics methods. PMID:26395941

  13. First wall and blanket module safety enhancement by material selection and design decision

    SciTech Connect

    Merrill, B.J.

    1980-01-01

    A thermal/mechanical study has been performed which illustrates the behavior of a fusion reactor first wall and blanket module during a loss of coolant flow event. The relative safety advantages of various material and design options were determined. A generalized first wall-blanket concept was developed to provide the flexibility to vary the structural material (stainless steel vs titanium), coolant (helium vs water), and breeder material (liquid lithium vs solid lithium aluminate). In addition, independent vs common first wall-blanket cooling and coupled adjacent module cooling design options were included in the study. The comparative analyses were performed using a modified thermal analysis code to handle phase change problems.

  14. Big-deep-smart data in imaging for guiding materials design

    NASA Astrophysics Data System (ADS)

    Kalinin, Sergei V.; Sumpter, Bobby G.; Archibald, Richard K.

    2015-10-01

    Harnessing big data, deep data, and smart data from state-of-the-art imaging might accelerate the design and realization of advanced functional materials. Here we discuss new opportunities in materials design enabled by the availability of big data in imaging and data analytics approaches, including their limitations, in material systems of practical interest. We specifically focus on how these tools might help realize new discoveries in a timely manner. Such methodologies are particularly appropriate to explore in light of continued improvements in atomistic imaging, modelling and data analytics methods.

  15. Material selection indices for design of surgical instruments with long tubular shafts.

    PubMed

    Nelson, Carl A

    2013-02-01

    In any medical device design process, material selection plays an important role. For devices which sustain mechanical loading, strength and stiffness requirements can be significant drivers of the design. This paper examines the specific case of minimally invasive surgical instruments, including robotic instruments, having long, tubular shafts. Material properties-based selection indices are derived for achieving high performance of these devices in terms of strength and stiffness, and the use of these indices for informing the medical device design problem is illustrated. PMID:23360192

  16. Application of the ASME code in designing containment vessels for packages used to transport radioactive materials

    SciTech Connect

    Raske, D.T.; Wang, Z.

    1992-07-01

    The primary concern governing the design of shipping packages containing radioactive materials is public safety during transport. When these shipments are within the regulatory jurisdiction of the US Department of Energy, the recommended design criterion for the primary containment vessel is either Section III or Section VIII, Division 1, of the ASME Boiler and Pressure Vessel Code, depending on the activity of the contents. The objective of this paper is to discuss the design of a prototypic containment vessel representative of a packaging for the transport of high-level radioactive material.

  17. Materials, Processes and Manufacturing in Ares 1 Upper Stage: Integration with Systems Design and Development

    NASA Technical Reports Server (NTRS)

    Bhat, Biliyar N.

    2008-01-01

    Ares I Crew Launch Vehicle Upper Stage is designed and developed based on sound systems engineering principles. Systems Engineering starts with Concept of Operations and Mission requirements, which in turn determine the launch system architecture and its performance requirements. The Ares I-Upper Stage is designed and developed to meet these requirements. Designers depend on the support from materials, processes and manufacturing during the design, development and verification of subsystems and components. The requirements relative to reliability, safety, operability and availability are also dependent on materials availability, characterization, process maturation and vendor support. This paper discusses the roles and responsibilities of materials and manufacturing engineering during the various phases of Ares IUS development, including design and analysis, hardware development, test and verification. Emphasis is placed how materials, processes and manufacturing support is integrated over the Upper Stage Project, both horizontally and vertically. In addition, the paper describes the approach used to ensure compliance with materials, processes, and manufacturing requirements during the project cycle, with focus on hardware systems design and development.

  18. Packing design and materials for coal liquefaction slurry feed pumps. Interim Technical Report No. 2

    SciTech Connect

    Not Available

    1982-02-18

    Seven packing vendors responded to MTI's solicitation and provided packing designs and materials for coal liquefaction slurry feed pumps at the existing pilot plants. The pilot plants include EDS at Baytown, Texas, H-Coal at Catlettsburg, Kentucky, and SRC-I at Wilsonville, Alabama. Two basic types of packing designs were proposed by the vendors. The first type is the compression or jam type of pre-molded or cut-fit packing design. The options include up to eight rings of either identical or a combination of soft and hard packing material with or without end adapters. The second type of design proposed to the program is a chevron shaped and spring loaded type of pre-molded packing. The options include two to four rings of homogeneous and/or composite packing material with end adapters or spacers.

  19. Effects of Materials Parameters and Design Details on the Fatigue of Composite Materials for Wind Turbine Blades

    SciTech Connect

    Mandell, J.F.; Samborsky, D.D.; Sutherland, H.J.

    1999-03-04

    This paper presents an analysis of the results of nine years of fatigue testing represented in the USDOE/Montana State University (DOE/MSU) Composite Materials Fatigue Database. The focus of the program has been to explore a broad range of glass-fiber-based materials parameters encompassing over 4500 data points for 130 materials systems. Significant trends and transitions in fatigue resistance are shown as the fiber content and fabric architecture are varied. The effects of structural details including ply drops, bonded stiffeners, and other geometries that produce local variations in fiber packing and geometry are also described. Fatigue tests on composite beam structures are then discussed; these show generally good correlation with coupon fatigue data in the database. Goodman diagrams for fatigue design are presented, and their application to predicting the service lifetime of blades is described.

  20. Meta-lens design with low permittivity dielectric materials through smart transformation optics

    NASA Astrophysics Data System (ADS)

    Kim, Junhyun; Shin, Dongheok; Choi, Seungjae; Yoo, Do-Sik; Seo, Ilsung; Kim, Kyoungsik

    2015-09-01

    We report here a design method based on smart transformation optics (STO) to control the range of the permittivity values of the materials required to manufacture transformation optics devices. In particular, we show that it is possible to reduce the maximum electric permittivity value required to realize a STO device with certain functionality by means of a simple conceptual elastic stretching process. We illustrate the design procedure with two types of collimator meta-lens designs, which we call warping space collimator meta-lens and half fisheye collimator meta-lens, respectively. We provide design examples of these two types of lenses with the help of COMSOL Multiphysics software. These two design examples are fabricated with commonly available dielectric materials by means of 3D printing technology. For the functional verification of these two collimator lenses, we provide measurement results obtained with transverse electric waves of frequency range 7-13GHz.

  1. Designing and Developing Online Materials for Molecular Biology: Building Online Programs for Science.

    PubMed

    Boulay, Rachel

    2013-01-01

    A well-accepted form of educational training offered in molecular biology is internships in research laboratories. However, the number of available research laboratories severely limits access by most students. Addressing this need, the University of Hawaii launched a project to expand this model to include newly developed online training materials in addition to a hands-on laboratory experience. This paper explores the design and development process of the online learning materials. This case study looks at the roles of the instructional designer, multimedia specialist, and research faculty who were the subject matter experts. The experiences of the design teams are shared in an effort to gain insight on how the collaborative efforts of the project group led to a successful deployment of the online learning materials. PMID:24319699

  2. The effect of new priorities and new materials on residential refrigerator design

    SciTech Connect

    Benson, D.K.; Potter, T.F.

    1992-08-01

    Increasing energy-efficiency requirements, combined with environmental considerations, have resulted in designs for domestic refrigerators that incorporate new thermal insulating materials. The first series of tests of these materials have been sufficiently promising that incorporation of vacuum insulations if likely within the next several years. Initial designs will probably use a combination of vacuum insulations and foam; in future designs, major parts consolidation will be possible using structural and other characteristics of the new panel assemblies. Given optimization of the refrigerator thermal envelope according to life-cycle costs, energy use by refrigerators could be greatly reduced; refrigerators could lose their significance as a major component in residential energy-use. Possible forms in which these new materials will be used are discussed, including alternatives for composite assembly and requirements for reliability and durability.

  3. Rational Design of Diketopyrrolopyrrole-Based Small Molecules as Donating Materials for Organic Solar Cells

    PubMed Central

    Jin, Ruifa; Wang, Kai

    2015-01-01

    A series of diketopyrrolopyrrole-based small molecules have been designed to explore their optical, electronic, and charge transport properties as organic solar cell (OSCs) materials. The calculation results showed that the designed molecules can lower the band gap and extend the absorption spectrum towards longer wavelengths. The designed molecules own the large longest wavelength of absorption spectra, the oscillator strength, and absorption region values. The optical, electronic, and charge transport properties of the designed molecules are affected by the introduction of different ?-bridges and end groups. We have also predicted the mobility of the designed molecule with the lowest total energies. Our results reveal that the designed molecules are expected to be promising candidates for OSC materials. Additionally, the designed molecules are expected to be promising candidates for electron and/or hole transport materials. On the basis of our results, we suggest that molecules under investigation are suitable donors for [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and its derivatives as acceptors of OSCs. PMID:26343640

  4. Rational Design of Diketopyrrolopyrrole-Based Small Moleculesas Donating Materials for Organic Solar Cells.

    PubMed

    Jin, Ruifa; Wang, Kai

    2015-01-01

    A series of diketopyrrolopyrrole-based small molecules have been designed to explore their optical, electronic, and charge transport properties as organic solar cell(OSCs) materials. The calculation results showed that the designed molecules can lower the band gap and extend the absorption spectrum towards longer wavelengths.The designed molecules own the large longest wavelength of absorption spectra,the oscillator strength, and absorption region values. The optical, electronic, and charge transport properties of the designed molecules are affected by the introduction of different ?-bridges and end groups. We have also predicted the mobility of the designed molecule with the lowest total energies. Our results reveal that the designed molecules are expected to be promising candidates for OSC materials. Additionally, the designed molecules are expected to be promising candidates for electron and/or hole transport materials. On the basis of our results, we suggest that molecules under investigation are suitable donors for[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and its derivatives as acceptors of OSCs. PMID:26343640

  5. Bioactive ceramic-based materials with designed reactivity for bone tissue regeneration

    PubMed Central

    Ohtsuki, Chikara; Kamitakahara, Masanobu; Miyazaki, Toshiki

    2009-01-01

    Bioactive ceramics have been used clinically to repair bone defects owing to their biological affinity to living bone; i.e. the capability of direct bonding to living bone, their so-called bioactivity. However, currently available bioactive ceramics do not satisfy every clinical application. Therefore, the development of novel design of bioactive materials is necessary. Bioactive ceramics show osteoconduction by formation of biologically active bone-like apatite through chemical reaction of the ceramic surface with surrounding body fluid. Hence, the control of their chemical reactivity in body fluid is essential to developing novel bioactive materials as well as biodegradable materials. This paper reviews novel bioactive materials designed based on chemical reactivity in body fluid. PMID:19158015

  6. Data mining for materials design: A computational study of single molecule magnet

    SciTech Connect

    Dam, Hieu Chi; Faculty of Physics, Vietnam National University, 334 Nguyen Trai, Hanoi ; Pham, Tien Lam; Ho, Tu Bao; Nguyen, Anh Tuan; Nguyen, Viet Cuong

    2014-01-28

    We develop a method that combines data mining and first principles calculation to guide the designing of distorted cubane Mn{sup 4+} Mn {sub 3}{sup 3+} single molecule magnets. The essential idea of the method is a process consisting of sparse regressions and cross-validation for analyzing calculated data of the materials. The method allows us to demonstrate that the exchange coupling between Mn{sup 4+} and Mn{sup 3+} ions can be predicted from the electronegativities of constituent ligands and the structural features of the molecule by a linear regression model with high accuracy. The relations between the structural features and magnetic properties of the materials are quantitatively and consistently evaluated and presented by a graph. We also discuss the properties of the materials and guide the material design basing on the obtained results.

  7. Preliminary Design and Investigation of Integrated Compressor with Composite Material Wheel

    NASA Astrophysics Data System (ADS)

    Wang, Jifeng; Müller, Norbert

    2012-06-01

    An integrated water vapor compressor with composite material wheel is developed and strength analysis using FEM is presented. The design of wound composite material allows for integrating all rotating parts of the drive that may simply reduce to only the rotor of the electrical motor, since no drive shaft is required anymore. This design can reduce the number of parts and mass, which is convenient for engineers to maintain the compressor. The electrical motors are brushless DC motors operating through a frequency drive and apply a torque on the wheels through the materials bonded in the wheel shrouds. This system allows a large amount of compression to be produced in a multi-stage compression setup. To determine the stress and vibration characteristics of this integrated compressor, numerical analysis is carried out using FEM. The simulation result shows that the integrated compressor with composite material wheel can be used in a chiller system where water as a refrigerant.

  8. Virtual Welded-Joint Design Integrating Advanced Materials and Processing Technologies

    SciTech Connect

    Yang, Z.; Dong, P.; Liu, S.; Babu, S.; Olson, G.; DebRoy, T.

    2005-04-15

    The primary goal of this project is to increase the fatigue life of a welded-joint by 10 times and to reduce energy use by 25% through product performance and productivity improvements using an integrated modeling approach. The fatigue strength of a welded-joint is currently the bottleneck to design high performance and lightweight welded structures using advanced materials such as high strength steels. In order to achieve high fatigue strength in a welded-joint it is necessary to manage the weld bead shape for lower stress concentration, produce preferable residual stress distribution, and obtain the desired microstructure for improved material toughness and strength. This is a systems challenge that requires the optimization of the welding process, the welding consumable, the base material, as well as the structure design. The concept of virtual welded-joint design has been proposed and established in this project. The goal of virtual welded-joint design is to develop a thorough procedure to predict the relationship of welding process, microstructure, property, residual stress, and the ultimate weld fatigue strength by a systematic modeling approach. The systematic approach combines five sub-models: weld thermal-fluid model, weld microstructure model, weld material property model, weld residual stress model, and weld fatigue model. The systematic approach is thus based on interdisciplinary applied sciences including heat transfer, computational fluid dynamics, materials science, engineering mechanics, and material fracture mechanics. The sub-models are based on existing models with further development. The results from modeling have been validated with critical experiments. The systematic modeling approach has been used to design high fatigue resistant welds considering the combined effects of weld bead geometry, residual stress, microstructure, and material property. In particular, a special welding wire has been developed in this project to introduce compressive residual stress at weld toe for weld fatigue resistance.

  9. Materials and design experience in a slurry-fed electric glass melter

    SciTech Connect

    Barnes, S.M.; Larson, D.E.

    1981-08-01

    The design of a slurry-fed electric gas melter and an examination of the performance and condition of the construction materials were completed. The joule-heated, ceramic-lined melter was constructed to test the applicability of materials and processes for high-level waste vitrification. The developmental Liquid-Fed Ceramic Melter (LFCM) was operated for three years with simulated high-level waste and was subjected to conditions more severe than those expected for a nuclear waste vitrification plant.

  10. Stress distributions in maxillary central incisors restored with various types of post materials and designs.

    PubMed

    Madfa, A A; Kadir, M R Abdul; Kashani, J; Saidin, S; Sulaiman, E; Marhazlinda, J; Rahbari, R; Abdullah, B J J; Abdullah, H; Abu Kasim, N H

    2014-07-01

    Different dental post designs and materials affect the stability of restoration of a tooth. This study aimed to analyse and compare the stability of two shapes of dental posts (parallel-sided and tapered) made of five different materials (titanium, zirconia, carbon fibre and glass fibre) by investigating their stress transfer through the finite element (FE) method. Ten three-dimensional (3D) FE models of a maxillary central incisor restored with two different designs and five different materials were constructed. An oblique loading of 100 N was applied to each 3D model. Analyses along the centre of the post, the crown-cement/core and the post-cement/dentine interfaces were computed, and the means were calculated. One-way ANOVAs followed by post hoc tests were used to evaluate the effectiveness of the post materials and designs (p=0.05). For post designs, the tapered posts introduced significantly higher stress compared with the parallel-sided post (p<0.05), especially along the centre of the post. Of the materials, the highest level of stress was found for stainless steel, followed by zirconia, titanium, glass fibre and carbon fibre posts (p<0.05). The carbon and glass fibre posts reduced the stress distribution at the middle and apical part of the posts compared with the stainless steel, zirconia and titanium posts. The opposite results were observed at the crown-cement/core interface. PMID:24834856

  11. Sustainable manufacturing: Effect of material selection and design on the environmental impact in the manufacturing process

    NASA Astrophysics Data System (ADS)

    Hazwan Syafiq Harun, Mohd; Taha, Zahari; Salaam, Hadi Abdul

    2013-12-01

    The environmental impact of a manufacturing process is also dependent on the selection of the material and design of a product. This is because the manufacturing of a product is directly connected to the amount of carbon emitted in consuming the electrical energy for that manufacturing process. The difference in the general properties of materials such as strength, hardness and impact will have significant effect on the power consumption of the machine used to complete the product. In addition the environmental impact can also be reduced if the proposed designs use less material. In this study, an LCA tool called Eco-It is used. Evaluate the environmental impact caused by manufacturing simple jig. A simple jig with 4 parts was used as a case study. Two experiments were carried out. The first experiment was to study the environmental effects of different material, and the second experiment was to study the environmental impact of different design. The materials used for the jig are Aluminium and mild steel. The results showed a decrease in the rate of carbon emissions by 60% when Aluminium is use instead from mild steel, and a decrease of 26% when the-design is modified.

  12. Analysis of Photothermal Characterization of Layered Materials: Design of Optimal Experiments

    NASA Technical Reports Server (NTRS)

    Cole, Kevin D.

    2003-01-01

    In this paper numerical calculations are presented for the steady-periodic temperature in layered materials and functionally-graded materials to simulate photothermal methods for the measurement of thermal properties. No laboratory experiments were performed. The temperature is found from a new Green s function formulation which is particularly well-suited to machine calculation. The simulation method is verified by comparison with literature data for a layered material. The method is applied to a class of two-component functionally-graded materials and results for temperature and sensitivity coefficients are presented. An optimality criterion, based on the sensitivity coefficients, is used for choosing what experimental conditions will be needed for photothermal measurements to determine the spatial distribution of thermal properties. This method for optimal experiment design is completely general and may be applied to any photothermal technique and to any functionally-graded material.

  13. Accelerated materials property predictions and design using motif-based fingerprints

    E-print Network

    Huan, Tran Doan; Ramprasad, Rampi

    2015-01-01

    Data-driven approaches are particularly useful for computational materials discovery and design as they can be used for rapidly screening over a very large number of materials, thus suggesting lead candidates for further in-depth investigations. A central challenge of such approaches is to develop a numerical representation, often referred to as a fingerprint, of the materials. Inspired by recent developments in chem-informatics, we propose a class of hierarchical motif-based topological fingerprints for materials composed of elements such as C, O, H, N, F, etc., whose coordination preferences are well understood. We show that these fingerprints, when representing either molecules or crystals, may be effectively mapped onto a variety of properties using a similarity-based learning model and hence can be used to predict relevant properties of a material, given that its fingerprint can be defined. Two simple procedures are introduced to demonstrate that the learning model can be inverted to identify the desired...

  14. [Design and Preparation of Plant Bionic Materials Based on Optical and Infrared Features Simulation].

    PubMed

    Jiang, Xiao-jun; Lu, Xu-liang; Pan, Jia-liang; Zhang, Shuan-qin

    2015-07-01

    Due to the life characteristics such as physiological structure and transpiration, plants have unique optical and infrared features. In the optical band, because of the common effects of chlorophyll and water, plant leafs show spectral reflectance characteristics change in 550, 680, 1400 and 1900 nm significantly. In the infrared wave band, driven by transpiration, plants could regulate temperature on their own initiative, which make the infrared characteristics of plants different from artificial materials. So palnt bionic materials were proposed to simulate optical and infrared characteristics of plants. By analyzing formation mechanism of optical and infrared features about green plants, the component design and heat-transfer process of plants bionic materials were studied, above these the heat-transfer control formulation was established. Based on water adsorption/release compound, optical pigments and other man-made materials, plant bionic materials preparation methods were designed which could simulate the optical and infrared features of green plants. By chemical casting methods plant bionic material films were prepared, which use polyvinyl alcohol as film forming and water adsorption/release compound, and use optical pigments like chrome green and macromolecule yellow as colouring materials. The research conclusions achieved by testings figured out: water adsorption/release testing showed that the plant bionic materials with a certain thickness could absorb 1.3 kg water per square meter, which could satisfy the water usage of transpiration simulation one day; the optical and infrared simulated effect tests indicated that the plant bionic materials could preferably simulate the spectral reflective performance of green plants in optical wave band (380-2500 nm, expecially in 1400 and 1900 nm which were water absorption wave band of plants), and also it had similar daily infrared radiation variations with green plants, daily average radiation temperature difference was 0.37 degrees C, maximum radiation temperature difference was 0.9 degrees C; so according to the testing results, the materials behave well plant bionic performance. PMID:26717735

  15. Advanced composites structural concepts and materials technologies for primary aircraft structures: Design/manufacturing concept assessment

    NASA Technical Reports Server (NTRS)

    Chu, Robert L.; Bayha, Tom D.; Davis, HU; Ingram, J. ED; Shukla, Jay G.

    1992-01-01

    Composite Wing and Fuselage Structural Design/Manufacturing Concepts have been developed and evaluated. Trade studies were performed to determine how well the concepts satisfy the program goals of 25 percent cost savings, 40 percent weight savings with aircraft resizing, and 50 percent part count reduction as compared to the aluminum Lockheed L-1011 baseline. The concepts developed using emerging technologies such as large scale resin transfer molding (RTM), automatic tow placed (ATP), braiding, out-of-autoclave and automated manufacturing processes for both thermoset and thermoplastic materials were evaluated for possible application in the design concepts. Trade studies were used to determine which concepts carry into the detailed design development subtask.

  16. Design of optical bandpass filters based on a two-material multilayer structure.

    PubMed

    Belyaev, B A; Tyurnev, V V; Shabanov, V F

    2014-06-15

    An easy method for designing filters with equalized passband ripples of a given magnitude is proposed. The filter, which is made of two dielectric materials, comprises coupled half-wavelength resonators and multilayer mirrors. The filter design begins with the synthesis of the multimaterial filter prototype whose mirrors consist of quarter-wavelength layers. Optimal refractive indices of the layers in the prototype are obtained by a special optimization based on universal rules. The thicknesses of the mirrors' layers in the final filter are computed using derived formulas. A design procedure example for silicon-air bandpass filters with a fractional bandwidth of 1% is described. PMID:24978524

  17. Design, Implementation, and Evaluation of GIS-Based Learning Materials in an Introductory Geoscience Course.

    ERIC Educational Resources Information Center

    Hall-Wallace, Michelle K.; McAuliffe, Carla M.

    2002-01-01

    Investigates student learning that occurred with a Geographic Information Systems (GIS) based module on plate tectonics and geologic hazards. Examines factors in the design and implementation of the materials that impacted student learning. Reports positive correlations between student' spatial ability and performance. Includes 17 references.…

  18. The Acceptability and Effectiveness of Textbook Material Revised Using Instructional Design Criteria.

    ERIC Educational Resources Information Center

    Mengel, Nancy S.

    1986-01-01

    This study demonstrated that, although standard instructional design revisions of a traditional textbook chapter had no effect on teacher attitudes toward adoption of the material, the revised version of the chapter significantly improved student performance. Teacher and student participants in the study were from the St. Petersburg…

  19. Taguchi statistical design and analysis of cleaning methods for spacecraft materials

    NASA Technical Reports Server (NTRS)

    Lin, Y.; Chung, S.; Kazarians, G. A.; Blosiu, J. O.; Beaudet, R. A.; Quigley, M. S.; Kern, R. G.

    2003-01-01

    In this study, we have extensively tested various cleaning protocols. The variant parameters included the type and concentration of solvent, type of wipe, pretreatment conditions, and various rinsing systems. Taguchi statistical method was used to design and evaluate various cleaning conditions on ten common spacecraft materials.

  20. Above Ground Geothermal and Allied Technologies Masters Scholarship in Energy & Materials: design of a rig

    E-print Network

    Hickman, Mark

    Above Ground Geothermal and Allied Technologies Masters Scholarship in Energy & Materials: design into the largest green energy resources; industrial waste heat, biomass combustion and geothermal energy. Research of geothermal energy after completing the degree. Proficiency in English is essential. Contact: mark

  1. Exploring the Effect of Materials Designed with Augmented Reality on Language Learners' Vocabulary Learning

    ERIC Educational Resources Information Center

    Solak, Ekrem; Cakir, Recep

    2015-01-01

    The purpose of this study was to determine the motivational level of the participants in a language classroom towards course materials designed in accordance with augmented reality technology and to identify the correlation between academic achievement and motivational level. 130 undergraduate students from a state-run university in Turkey…

  2. Test blanket modules in ITER: An overview on proposed designs and required DEMO-relevant materials

    E-print Network

    Abdou, Mohamed

    Test blanket modules in ITER: An overview on proposed designs and required DEMO-relevant materials, Russian Federation Abstract Within the framework of the ITER Test Blanket Working Group, the ITER Parties have made several proposals for test blanket modules to be tested in ITER from the first day of H

  3. A Study of Learning Performance of E-Learning Materials Design with Knowledge Maps

    ERIC Educational Resources Information Center

    Shaw, Ruey-Shiang

    2010-01-01

    This research investigated the application of knowledge maps in e-learning materials design and hypothesized that knowledge maps would be more effective than e-learning in general at improving the performance and satisfaction of e-learning. In order to test the hypotheses, we conducted an experiment with 175 participants and randomly assigned them…

  4. Design Guidelines for the Development of Digital Nutrigenomics Learning Material for Heterogeneous Target Groups

    ERIC Educational Resources Information Center

    Busstra, Maria C.; Hartog, Rob; Kersten, Sander; Muller, Michael

    2007-01-01

    Nutritional genomics, or nutrigenomics, can be considered as the combination of molecular nutrition and genomics. Students who attend courses in nutrigenomics differ with respect to their prior knowledge. This study describes digital nutrigenomics learning material suitable for students from various backgrounds and provides design guidelines for…

  5. Journal of Computer-Aided Materials Design, 9: 99132, 2002. KLUWER/ESCOM

    E-print Network

    Vitek, Vaclav

    Journal of Computer-Aided Materials Design, 9: 99­132, 2002. KLUWER/ESCOM © 2003 Kluwer Academic DOE programs such as ASCI (Accelerated Strategic Computing Initiative) [3], there has been spe- cial in the description of interatomic interactions, general modeling methodologies and computer performance, much remains

  6. Journal of Computer-Aided Materials Design, 6: 117127, 1999. KLUWER/ESCOM

    E-print Network

    Zhigilei, Leonid V.

    Journal of Computer-Aided Materials Design, 6: 117­127, 1999. KLUWER/ESCOM © 1999 Kluwer Academic in thin films. Multiple lattices are mapped onto a single reference lattice, with resulting computational, while others are not accessible by the available techniques. Computer simulations can often complement

  7. Journal of Computer-Aided Materials Design, 8: 185192, 2001. KLUWER/ESCOM

    E-print Network

    Goddard III, William A.

    Journal of Computer-Aided Materials Design, 8: 185­192, 2001. KLUWER/ESCOM © 2002 Kluwer Academic parallel computers. The method is a development of a spatial decomposition in 3-D space. Keywords: Metal, Molecular dynamics, Parallel computations 1. Introduction Molecular dynamics (MD) method

  8. Journal of Computer-Aided Materials Design, 6: 337347, 1999. KLUWER/ESCOM

    E-print Network

    Ghoniem, Nasr M.

    Journal of Computer-Aided Materials Design, 6: 337­347, 1999. KLUWER/ESCOM © 1999 Kluwer Academic.S.A. Received 1 September 1999; Accepted 21 October 1999 Abstract. A hierarchical, multi-scale computer model equations. This multi-scale model is shown to be a useful computer simulation tool, which can be utilized

  9. Color Research and Its Application to the Design of Instructional Materials.

    ERIC Educational Resources Information Center

    Pett, Dennis; Wilson, Trudy

    1996-01-01

    Reviews color research and considers its implications for the design of instructional materials. Topics include physiological and psychological effects; color and learning, including attention, search tasks, retention and other objective measures, and non-objective measures; color and the cathode ray tube (CRT); and further research needs.…

  10. Wiki-Based Rapid Prototyping for Teaching-Material Design in E-Learning Grids

    ERIC Educational Resources Information Center

    Shih, Wen-Chung; Tseng, Shian-Shyong; Yang, Chao-Tung

    2008-01-01

    Grid computing environments with abundant resources can support innovative e-Learning applications, and are promising platforms for e-Learning. To support individualized and adaptive learning, teachers are encouraged to develop various teaching materials according to different requirements. However, traditional methodologies for designing teaching…

  11. 1. INTRODUCTION Current design methods focus on crack growth curves which are material properties for given

    E-print Network

    Hively, Lee M.

    sustained loading of cracks) and stress corrosion cracking (KI scc, JI scc, sustained loading of cracks fatigue, as well as Mode I low-temperature creep and stress corrosion. During the 1930s, A. A. Griffith1. INTRODUCTION Current design methods focus on crack growth curves which are material properties

  12. Evaluation of critical materials in five additional advance design photovoltaic cells

    SciTech Connect

    Smith, S.A.; Watts, R.L.; Martin, P.; Gurwell, W.E.

    1981-02-01

    The objective of this study is to identify potential material supply constraints due to the large-scale deployment of five advanced photovoltaic (PV) cell designs, and to suggest strategies to reduce the impacts of these production capacity limitations and potential future material shortages. The Critical Materials Assessment Program (CMAP) screens the designs and their supply chains and identifies potential shortages which might preclude large-scale use of the technologies. The results of the screening of five advanced PV cell designs are presented: (1) indium phosphide/cadmium sulfide, (2) zinc phosphide, (3) cadmium telluride/cadmium sulfide, (4) copper indium selenium, and (5) cadmium selenide photoelectrochemical. Each of these five cells is screened individually assuming that they first come online in 1991, and that 25 Gwe of peak capacity is online by the year 2000. A second computer screening assumes that each cell first comes online in 1991 and that each cell has a 5 GWe of peak capacity by the year 2000, so that the total online capacity for the five cells is 25 GWe. Based on a review of the preliminary baseline screening results, suggestions were made for varying such parameters as the layer thickness, cell production processes, etc. The resulting PV cell characterizations were then screened again by the CMAP computer code. The CMAP methodology used to identify critical materials is described; and detailed characterizations of the advanced photovoltaic cell designs under investigation, descriptions of additional cell production processes, and the results are presented. (WHK)

  13. 75 FR 54497 - Ocean Dumping; Guam Ocean Dredged Material Disposal Site Designation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-08

    ... Register (FR). Historically, dredged material generated around Guam by the Navy and the Port Authority of...: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: The EPA is designating the Guam Deep Ocean... Street, SW., Washington, DC 20460. 10. EPA Web site:...

  14. Accelerating the Design of Solar Thermal Fuel Materials through High Throughput Simulations

    SciTech Connect

    Liu, Y; Grossman, JC

    2014-12-01

    Solar thermal fuels (STF) store the energy of sunlight, which can then be released later in the form of heat, offering an emission-free and renewable solution for both solar energy conversion and storage. However, this approach is currently limited by the lack of low-cost materials with high energy density and high stability. In this Letter, we present an ab initio high-throughput computational approach to accelerate the design process and allow for searches over a broad class of materials. The high-throughput screening platform we have developed can run through large numbers of molecules composed of earth-abundant elements and identifies possible metastable structures of a given material. Corresponding isomerization enthalpies associated with the metastable structures are then computed. Using this high-throughput simulation approach, we have discovered molecular structures with high isomerization enthalpies that have the potential to be new candidates for high-energy density STF. We have also discovered physical principles to guide further STF materials design through structural analysis. More broadly, our results illustrate the potential of using high-throughput ab initio simulations to design materials that undergo targeted structural transitions.

  15. APPLICATION FO FLOW FORMING FOR USE IN RADIOACTIVE MATERIAL PACKAGING DESIGNS

    SciTech Connect

    Blanton, P.; Eberl, K.; Abramczyk, G.

    2012-07-11

    This paper reports on the development and testing performed to demonstrate the use of flow forming as an alternate method of manufacturing containment vessels for use in radioactive material shipping packaging designs. Additionally, ASME Boiler and Pressure Vessel Code, Section III, Subsection NB compliance along with the benefits compared to typical welding of containment vessels will be discussed. SRNL has completed fabrication development and the testing on flow formed containment vessels to demonstrate the use of flow forming as an alternate method of manufacturing a welded 6-inch diameter containment vessel currently used in the 9975 and 9977 radioactive material shipping packaging. Material testing and nondestructive evaluation of the flow formed parts demonstrate compliance to the minimum material requirements specified in applicable parts of ASME Boiler and Pressure Vessel Code, Section II. Destructive burst testing shows comparable results to that of a welded design. The benefits of flow forming as compared to typical welding of containment vessels are significant: dimensional control is improved due to no weld distortion; less final machining; weld fit-up issues associated with pipes and pipe caps are eliminated; post-weld non-destructive testing (i.e., radiography and die penetrant tests) is not necessary; and less fabrication steps are required. Results presented in this paper indicate some of the benefits in adapting flow forming to design of future radioactive material shipping packages containment vessels.

  16. A Data Envelopment Analysis Model for Selecting Material Handling System Designs

    NASA Astrophysics Data System (ADS)

    Liu, Fuh-Hwa Franklin; Kuo, Wan-Ting

    The material handling system under design is an unmanned job shop with an automated guided vehicle that transport loads within the processing machines. The engineering task is to select the design alternatives that are the combinations of the four design factors: the ratio of production time to transportation time, mean job arrival rate to the system, input/output buffer capacities at each processing machine, and the vehicle control strategies. Each of the design alternatives is simulated to collect the upper and lower bounds of the five performance indices. We develop a Data Envelopment Analysis (DEA) model to assess the 180 designs with imprecise data of the five indices. The three-ways factorial experiment analysis for the assessment results indicates the buffer capacity and the interaction of job arrival rate and buffer capacity affect the performance significantly.

  17. Preliminary design polymeric materials experiment. [for space shuttles and Spacelab missions

    NASA Technical Reports Server (NTRS)

    Mattingly, S. G.; Rude, E. T.; Marshner, R. L.

    1975-01-01

    A typical Advanced Technology Laboratory mission flight plan was developed and used as a guideline for the identification of a number of experiment considerations. The experiment logistics beginning with sample preparation and ending with sample analysis are then overlaid on the mission in order to have a complete picture of the design requirements. The results of this preliminary design study fall into two categories. First specific preliminary designs of experiment hardware which is adaptable to a variety of mission requirements. Second, identification of those mission considerations which affect hardware design and will require further definition prior to final design. Finally, a program plan is presented which will provide the necessary experiment hardware in a realistic time period to match the planned shuttle flights. A bibliography of all material reviewed and consulted but not specifically referenced is provided.

  18. Gradient-Index Materials, Design, and Metrology for Broadband Imaging Systems

    NASA Astrophysics Data System (ADS)

    McCarthy, Peter W.

    Gradient-index (GRIN) materials have an index of refraction that varies as a function of position. Compared to traditional homogeneous optical elements, the new degrees of freedom that are available with a GRIN optical element, especially the chromatic dispersion, are very beneficial in the design of broadband imaging systems. GRIN materials allow the optical designer to improve the performance of an imaging system, or, to maintain the performance and decrease the size, weight, and/or number of elements. However, there are many challenges in the design, fabrication, and metrology of GRIN optical elements. This thesis develops a general gradient-index material model that is used to represent real and theoretical GRIN materials. The model allows for analyzing the chromatic properties of GRIN materials in a way that is familiar to the optical designer. It also serves as a framework for constraining the chromatic properties of GRIN materials during the optimization of index of refraction profiles in lens design software. The model and optimization constraints are used in design studies in the 1-5 ?m infrared spectral band and 350-360 nm near-ultraviolet spectral band. These design studies demonstrate the ability of GRIN elements to improve the performance of an optical system or reduce the size, weight, and/or number of elements compared to homogeneous designs. A diffusion model with a composition-dependent diffusion coefficient is developed for fabricating gradient-index aluminum oxynitride (ALON). A method for using the diffusion model to fabricate deterministic GRIN profiles is presented. Finally, non-destructive metrology methods for the characterization of gradient-index lens blanks are investigated. Two methods are developed for determining the orientation of an axial GRIN distribution within a lens blank and these techniques are applied to a fabricated polymer GRIN blank. Improvements are made to a beam deflection technique for non-destructive characterization of one-dimensional gradient-index profiles. An automated deflectometer instrument is constructed and used to measure polychromatic index of refraction profiles of a polymer GRIN sample in order to determine the Abbe number of the gradient.

  19. Interfacial metallurgy study of brazed joints between tungsten and fusion related materials for divertor design

    NASA Astrophysics Data System (ADS)

    Zhang, Yuxuan; Galloway, Alexander; Wood, James; Robbie, Mikael Brian Olsson; Easton, David; Zhu, Wenzhong

    2014-11-01

    In the developing DEMO divertor, the design of joints between tungsten to other fusion related materials is a significant challenge as a result of the dissimilar physical metallurgy of the materials to be joined. This paper focuses on the design and fabrication of dissimilar brazed joints between tungsten and fusion relevant materials such as EUROFER 97, oxygen-free high thermal conductivity (OFHC) Cu and SS316L using a gold based brazing foil. The main objectives are to develop acceptable brazing procedures for dissimilar joining of tungsten to other fusion compliant materials and to advance the metallurgical understanding within the interfacial region of the brazed joint. Four different butt-type brazed joints were created and characterised, each of which were joined with the aid of a thin brazing foil (Au80Cu19Fe1, in wt.%). Microstructural characterisation and elemental mapping in the transition region of the joint was undertaken and, thereafter, the results were analysed as was the interfacial diffusion characteristics of each material combination produced. Nano-indentation tests are performed at the joint regions and correlated with element composition information in order to understand the effects of diffused elements on mechanical properties. The experimental procedures of specimen fabrication and material characterisation methods are presented. The results of elemental transitions after brazing are reported. Elastic modulus and nano-hardness of each brazed joints are reported.

  20. Space shuttle seal material and design development for earth storable propellant systems

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The results of a program to investigate and characterize seal materials suitable for space shuttle storable propellant systems are given. Two new elastomeric materials were identified as being potentially superior to existing state-of-the art materials for specific sealing applications. These materials were AF-E-124D and AF-E-411. AF-E-124D is a cured perfluorinated polymer suitable for use with dinitrogen tetroxide oxidizer, and hydrazine base fuels. AF-E-411 is an ethylene propylene terpolymer material for hydrazine base fuel service. Data are presented relative to low and high temperature characteristics as well as propellant exposure effects. Types of data included are: mechanical properties, stress strain curves, friction and wear characteristics, compression set and permeability. Sealing tests with a flat poppet-seal valve were conducted for verification of sealing capability. A bibliography includes over 200 references relating to seal design or materials and presents a concise tabulation of the more useful seal design data sources.

  1. Metal-organic Frameworks as A Tunable Platform for Designing Functional Molecular Materials

    PubMed Central

    Wang, Cheng; Liu, Demin

    2013-01-01

    Metal-organic frameworks (MOFs), also known as coordination polymers, represent an interesting class of crystalline molecular materials that are synthesized by combining metal-connecting points and bridging ligands. The modular nature of and mild conditions for MOF synthesis have permitted the rational structural design of numerous MOFs and the incorporation of various functionalities via constituent building blocks. The resulting designer MOFs have shown promise for applications in a number of areas, including gas storage/separation, nonlinear optics/ferroelectricity, catalysis, energy conversion/storage, chemical sensing, biomedical imaging, and drug delivery. The structure-property relationships of MOFs can also be readily established by taking advantage of the knowledge of their detailed atomic structures, which enables fine-tuning of their functionalities for desired applications. Through the combination of molecular synthesis and crystal engineering MOFs thus present an unprecedented opportunity for the rational and precise design of functional materials. PMID:23944646

  2. Engineered materials characterization report for the Yucca Mountain Site Characterization Project. Volume 2, Design data

    SciTech Connect

    Konynenburg, R.A.; McCright, R.D.; Roy, A.K.; Jones, D.A.

    1995-08-01

    This is Volume 2 of the Engineered Materials Characterization Report which presents the design data for candidate materials needed in fabricating different components for both large and medium multi-purpose canister (MPC) disposal containers, waste packages for containing uncanistered spent fuel (UCF), and defense high-level waste (HLW) glass disposal containers. The UCF waste package consists of a disposal container with a basket therein. It is assumed that the waste packages will incorporate all-metallic multibarrier disposal containers to accommodate medium and large MPCs, ULCF, and HLW glass canisters. Unless otherwise specified, the disposal container designs incorporate an outer corrosion-allowance metal barrier over an inner corrosion-resistant metal barrier. The corrosion-allowance barrier, which will be thicker than the inner corrosion-resistant barrier, is designed to undergo corrosion-induced degradation at a very low rate, thus providing the inner barrier protection from the near-field environment for a prolonged service period.

  3. Specimen Designs for Testing Advanced Aeropropulsion Materials Under In-Plane Biaxial Loading

    NASA Technical Reports Server (NTRS)

    Ellis, John R.; Abul-Aziz, Ali

    2003-01-01

    A design study was undertaken to develop specimen designs for testing advanced aeropropulsion materials under in-plane biaxial loading. The focus of initial work was on developing a specimen design suitable for deformation and strength tests to be conducted under monotonic loading. The type of loading initially assumed in this study was the special case of equibiaxial, tensile loading. A specimen design was successfully developed after a lengthy design and optimization process with overall dimensions of 12 by 12 by 0.625 in., and a gage area of 3.875 by 3.875 by 0.080 in. Subsequently, the scope of the work was extended to include the development of a second design tailored for tests involving cyclic loading. A specimen design suitably tailored to meet these requirements was successfully developed with overall dimensions of 12 by 12 by 0.500 in. and a gage area of 2.375 by 2.375 by 0.050 in. Finally, an investigation was made to determine whether the specimen designs developed in this study for equibiaxial, tensile loading could be used without modification to investigate general forms of biaxial loading. For best results, it was concluded that specimen designs need to be optimized and tailored to meet the specific loading requirements of individual research programs.

  4. Magnetically tunable double-negative material composed of ferrite-dielectric and metallic mesh

    NASA Astrophysics Data System (ADS)

    He, Guanghua; Wu, Rui-xin; Poo, Yin; Chen, Ping

    2010-05-01

    We designed and studied a magnetic tunable metamaterial composed of ferrite-dielectric and metallic mesh. The retrieved electromagnetic parameters and the transmission characteristic showed the composite has a double-negative regime in magnetized state. Moreover, this regime is tunable in external magnetic fields. The composite has a lower loss with minimum about -0.3 dB/mm. The simulations of the wave propagation on the interface of the composite clearly display a negative refraction. The negative indexes calculated from Snell's law are in good agreement with the indexes retrieved from S parameters, quantitatively confirms the negative index of the composite.

  5. Safety Standard for Oxygen and Oxygen Systems: Guidelines for Oxygen System Design, Materials Selection, Operations, Storage, and Transportation

    NASA Technical Reports Server (NTRS)

    1996-01-01

    NASA's standard for oxygen system design, materials selection, operation, and transportation is presented. Minimum guidelines applicable to NASA Headquarters and all NASA Field Installations are contained.

  6. 77 FR 63312 - Notice of Intent: Designation of an Ocean Dredged Material Disposal Site (ODMDS) in Eastern Long...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-16

    ...whether one or more dredged material disposal sites will be designated under the MPRSA. The SEIS...applying the five general and eleven specific site selection criteria for designating ocean disposal sites presented in 40 CFR 228.5 and...

  7. Reference material for natural radionuclides in glass designed for underground experiments

    E-print Network

    Povinec, P P; Busto, J; Cerna, C; Degering, D; Hamajima, Y; Holy, K; Hult, M; Jeskovsky, M; Koehler, M; Kovacik, A; Laubenstein, M; Loaiza, P; Mamedov, F; Marquet, C; Mott, J; Mullerova, M; Perrot, F; Piquemal, F; Reyss, J -L; Saakyan, R; Simgen, H; Soule, B; Stanicek, J; Sykora, I; Stekl, I

    2015-01-01

    A reference material designed for the determination of natural radionuclides in solid samples (glass pellets) is described and the results of certification are presented. The material has been certified for 7 natural radionuclides (40K, 226Ra, 228Ra, 228Th, 232Th, 235U and 238U). An information value is given for 210Pb. Radon (222Rn) emanation experiments showed results comparable within participating laboratories, however, the number of data and precision was too low to carry out a certification process. The reference material may be used for quality management of analytical laboratories engaged in the high-sensitive analysis of radionuclides in the construction materials of detectors placed in ultra low background underground laboratories.

  8. Reference material for natural radionuclides in glass designed for underground experiments

    E-print Network

    P. P. Povinec; M. K. Pham; J. Busto; C. Cerna; D. Degering; Y. Hamajima; K. Holy; M. Hult; M. Jeskovsky; M. Koehler; A. Kovacik; M. Laubenstein; P. Loaiza; F. Mamedov; C. Marquet; J. Mott; M. Mullerova; F. Perrot; F. Piquemal; J. -L. Reyss; R. Saakyan; H. Simgen; B. Soule; J. Stanicek; I. Sykora; I. Stekl

    2015-07-12

    A reference material designed for the determination of natural radionuclides in solid samples (glass pellets) is described and the results of certification are presented. The material has been certified for 7 natural radionuclides (40K, 226Ra, 228Ra, 228Th, 232Th, 235U and 238U). An information value is given for 210Pb. Radon (222Rn) emanation experiments showed results comparable within participating laboratories, however, the number of data and precision was too low to carry out a certification process. The reference material may be used for quality management of analytical laboratories engaged in the high-sensitive analysis of radionuclides in the construction materials of detectors placed in ultra low background underground laboratories.

  9. The SNL100-02 blade : advanced core material design studies for the Sandia 100-meter blade.

    SciTech Connect

    Griffith, Daniel

    2013-11-01

    A series of design studies are performed to investigate the effects of advanced core materials and a new core material strategy on blade weight and performance for large blades using the Sandia 100-meter blade designs as a starting point. The initial core material design studies were based on the SNL100-01 100- meter carbon spar design. Advanced core material with improved performance to weight was investigated with the goal to reduce core material content in the design and reduce blade weight. A secondary element of the core study was to evaluate the suitability of core materials from natural, regrowable sources such as balsa and recyclable foam materials. The new core strategy for the SNL100-02 design resulted in a design mass of 59 tons, which is a 20% reduction from the most recent SNL100-01 carbon spar design and over 48% reduction from the initial SNL100-00 all-glass baseline blade. This document provides a description of the final SNL100-02 design, includes a description of the major design modifications, and summarizes the pertinent blade design information. This document is also intended to be a companion document to the distribution of the NuMAD blade model files for SNL100-02 that are made publicly available.

  10. Negative Dielectric Constant Material Based on Ion Conducting Materials

    NASA Technical Reports Server (NTRS)

    Gordon, Keith L. (Inventor); Kang, Jin Ho (Inventor); Park, Cheol (Inventor); Lillehei, Peter T. (Inventor); Harrison, Joycelyn S. (Inventor)

    2014-01-01

    Metamaterials or artificial negative index materials (NIMs) have generated great attention due to their unique and exotic electromagnetic properties. One exemplary negative dielectric constant material, which is an essential key for creating the NIMs, was developed by doping ions into a polymer, a protonated poly(benzimidazole) (PBI). The doped PBI showed a negative dielectric constant at megahertz (MHz) frequencies due to its reduced plasma frequency and an induction effect. The magnitude of the negative dielectric constant and the resonance frequency were tunable by doping concentration. The highly doped PBI showed larger absolute magnitude of negative dielectric constant at just above its resonance frequency than the less doped PBI.

  11. Optimal experimental designs for the estimation of thermal properties of composite materials

    NASA Technical Reports Server (NTRS)

    Scott, Elaine P.; Moncman, Deborah A.

    1994-01-01

    Reliable estimation of thermal properties is extremely important in the utilization of new advanced materials, such as composite materials. The accuracy of these estimates can be increased if the experiments are designed carefully. The objectives of this study are to design optimal experiments to be used in the prediction of these thermal properties and to then utilize these designs in the development of an estimation procedure to determine the effective thermal properties (thermal conductivity and volumetric heat capacity). The experiments were optimized by choosing experimental parameters that maximize the temperature derivatives with respect to all of the unknown thermal properties. This procedure has the effect of minimizing the confidence intervals of the resulting thermal property estimates. Both one-dimensional and two-dimensional experimental designs were optimized. A heat flux boundary condition is required in both analyses for the simultaneous estimation of the thermal properties. For the one-dimensional experiment, the parameters optimized were the heating time of the applied heat flux, the temperature sensor location, and the experimental time. In addition to these parameters, the optimal location of the heat flux was also determined for the two-dimensional experiments. Utilizing the optimal one-dimensional experiment, the effective thermal conductivity perpendicular to the fibers and the effective volumetric heat capacity were then estimated for an IM7-Bismaleimide composite material. The estimation procedure used is based on the minimization of a least squares function which incorporates both calculated and measured temperatures and allows for the parameters to be estimated simultaneously.

  12. In-Vessel Coil Material Failure Rate Estimates for ITER Design Use

    SciTech Connect

    L. C. Cadwallader

    2013-01-01

    The ITER international project design teams are working to produce an engineering design for construction of this large tokamak fusion experiment. One of the design issues is ensuring proper control of the fusion plasma. In-vessel magnet coils may be needed for plasma control, especially the control of edge localized modes (ELMs) and plasma vertical stabilization (VS). These coils will be lifetime components that reside inside the ITER vacuum vessel behind the blanket modules. As such, their reliability is an important design issue since access will be time consuming if any type of repair were necessary. The following chapters give the research results and estimates of failure rates for the coil conductor and jacket materials to be used for the in-vessel coils. Copper and CuCrZr conductors, and stainless steel and Inconel jackets are examined.

  13. Los Alamos National Laboratory new generation standard nuclear material storage container - the SAVY4000 design

    SciTech Connect

    Stone, Timothy Amos

    2010-01-01

    Incidents involving release of nuclear materials stored in containers of convenience such as food pack cans, slip lid taped cans, paint cans, etc. has resulted in defense board concerns over the lack of prescriptive performance requirements for interim storage of nuclear materials. Los Alamos National Laboratory (LANL) has shared in these incidents and in response proactively moved into developing a performance based standard involving storage of nuclear material (RD003). This RD003 requirements document has sense been updated to reflect requirements as identified with recently issued DOE M 441.1-1 'Nuclear Material Packaging Manual'. The new packaging manual was issued at the encouragement of the Defense Nuclear Facilities Safety Board with a clear directive for protecting the worker from exposure due to loss of containment of stored materials. The Manual specifies a detailed and all inclusive approach to achieve a high level of protection; from package design & performance requirements, design life determinations of limited life components, authorized contents evaluations, and surveillance/maintenance to ensure in use package integrity over time. Materials in scope involve those stored outside an approved engineered-contamination barrier that would result in a worker exposure of in excess of 5 rem Committed Effective Does Equivalent (CEDE). Key aspects of meeting the challenge as developed around the SAVY-3000 vented storage container design will be discussed. Design performance and acceptance criteria against the manual, bounding conditions as established that the user must ensure are met to authorize contents in the package (based upon the activity of heat-source plutonium (90% Pu-238) oxide, which bounds the requirements for weapons-grade plutonium oxide), interface as a safety class system within the facility under the LANL plutonium facility DSA, design life determinations for limited life components, and a sense of design specific surveillance program implementation as LANL moves forward into production and use of the SAVY-3000 will all be addressed. The SAVY-3000 is intended as a work horse package for the DOE complex as a vented storage container primarily for plutonium in solid form.

  14. Materials and fractal designs for 3D multifunctional integumentary membranes with capabilities in cardiac electrotherapy.

    PubMed

    Xu, Lizhi; Gutbrod, Sarah R; Ma, Yinji; Petrossians, Artin; Liu, Yuhao; Webb, R Chad; Fan, Jonathan A; Yang, Zijian; Xu, Renxiao; Whalen, John J; Weiland, James D; Huang, Yonggang; Efimov, Igor R; Rogers, John A

    2015-03-11

    Advanced materials and fractal design concepts form the basis of a 3D conformal electronic platform with unique capabilities in cardiac electrotherapies. Fractal geometries, advanced electrode materials, and thin, elastomeric membranes yield a class of device capable of integration with the entire 3D surface of the heart, with unique operational capabilities in low power defibrillation. Co-integrated collections of sensors allow simultaneous monitoring of physiological responses. Animal experiments on Langendorff-perfused rabbit hearts demonstrate the key features of these systems. PMID:25641076

  15. Design Features and Capabilities of the First Materials Science Research Rack

    NASA Technical Reports Server (NTRS)

    Pettigrew, P. J.; Lehoczky, S. L.; Cobb, S. D.; Holloway, T.; Kitchens, L.

    2003-01-01

    The First Materials Science Research Rack (MSRR-1) aboard the International Space Station (ISS) will offer many unique capabilities and design features to facilitate a wide range of materials science investigations. The initial configuration of MSRR-1 will accommodate two independent Experiment Modules (EMS) and provide the capability for simultaneous on-orbit processing. The facility will provide the common subsystems and interfaces required for the operation of experiment hardware and accommodate telescience capabilities. MSRR1 will utilize an International Standard Payload Rack (ISPR) equipped with an Active Rack Isolation System (ARIS) for vibration isolation of the facility.

  16. Design and "As Flown" Radiation Environments for Materials in Low Earth Orbits

    NASA Technical Reports Server (NTRS)

    Minow, Joseph I.; Altstatt, Richard L.; McWilliams, Brett; Koontz, Steven L.

    2006-01-01

    The design estimate for the materials for the International Space Station (ISS) specified in SSP 30512 was a conservative estimate. The environment dose was over estimated. The materials originally qualified for approximately 10-15 years are anticipated to be acceptable for periods of up to 20-30 years based on SSP-30512 or 40-60 years based on 2x SSP-30512. This viewgraph presentation shows charts and graphs that review the altitude, the solar minimum and maximum, and the radiation exposure of other satellite, among other graphics.

  17. New Lithium Solid Electrolytes, Thio-Lisicon Materials Design Concept and Application to Solid State Battery

    NASA Astrophysics Data System (ADS)

    Kanno, Ryoji; Murayama, Masahiro; Sakamoto, Kazuyuki

    2002-12-01

    Materials design concept of the new crystalline 'thio-LlSICON' (LIthium Superlonic CONductor) family was discussed. The thio-LISICON was found in the ternary systems, Li2S-MS2-M'xSy (M=Si, Ge, M'=P, Sb, Al, Zn, etc), and showed the highest conductivity of 2.2 × 10-3 Scm-1 at 25°C of any sintered ceramic, together with negligible electronic conductivity, high electrochemical stability, no reaction with lithium metal, and no phase transition up to 300°C. The advantage and disadvantage of the crystalline materials were discussed based on the ionic conduction, chemical stability and electrochemical potential window.

  18. Material Control and Accounting Design Considerations for High-Temperature Gas Reactors

    SciTech Connect

    Trond Bjornard; John Hockert

    2011-08-01

    The subject of this report is domestic safeguards and security by design (2SBD) for high-temperature gas reactors, focusing on material control and accountability (MC&A). The motivation for the report is to provide 2SBD support to the Next Generation Nuclear Plant (NGNP) project, which was launched by Congress in 2005. This introductory section will provide some background on the NGNP project and an overview of the 2SBD concept. The remaining chapters focus specifically on design aspects of the candidate high-temperature gas reactors (HTGRs) relevant to MC&A, Nuclear Regulatory Commission (NRC) requirements, and proposed MC&A approaches for the two major HTGR reactor types: pebble bed and prismatic. Of the prismatic type, two candidates are under consideration: (1) GA's GT-MHR (Gas Turbine-Modular Helium Reactor), and (2) the Modular High-Temperature Reactor (M-HTR), a derivative of Areva's Antares reactor. The future of the pebble-bed modular reactor (PBMR) for NGNP is uncertain, as the PBMR consortium partners (Westinghouse, PBMR [Pty] and The Shaw Group) were unable to agree on the path forward for NGNP during 2010. However, during the technology assessment of the conceptual design phase (Phase 1) of the NGNP project, AREVA provided design information and technology assessment of their pebble bed fueled plant design called the HTR-Module concept. AREVA does not intend to pursue this design for NGNP, preferring instead a modular reactor based on the prismatic Antares concept. Since MC&A relevant design information is available for both pebble concepts, the pebble-bed HTGRs considered in this report are: (1) Westinghouse PBMR; and (2) AREVA HTR-Module. The DOE Office of Nuclear Energy (DOE-NE) sponsors the Fuel Cycle Research and Development program (FCR&D), which contains an element specifically focused on the domestic (or state) aspects of SBD. This Material Protection, Control and Accountancy Technology (MPACT) program supports the present work summarized in this report, namely the development of guidance to support the consideration of MC&A in the design of both pebble-bed and prismatic-fueled HTGRs. The objective is to identify and incorporate design features into the facility design that will cost effectively aid in making MC&A more effective and efficient, with minimum impact on operations. The theft of nuclear material is addressed through both MC&A and physical protection, while the threat of sabotage is addressed principally through physical protection.

  19. COMPARISON OF THE TRADITIONAL STRENGTH OF MATERIALS APPROACH TO DESIGN WITH THE FRACTURE MECHANICS APPROACH

    SciTech Connect

    Z. Ceylan

    2002-04-30

    The objective of this activity is to show that the use of the traditional strength of materials approach to the drip shield and the waste package (WP) designs is bounding and appropriate when compared to the fracture mechanics approach. The scope of this activity is limited to determining the failure assessment diagrams for the two materials at issue: Ti-7 and Alloy 22. This calculation is intended for use in support of the license application design of the drip shield and the WP. This activity is associated with the drip shield and the WP designs. The activity evaluation for work package number P32 12234F2, included in ''Technical Work Plan for: Waste Package Design Description for LA'' (Ref. 1, p. A-6), has determined that the development of this document is subject to ''Quality Assurance Requirements and Description'' requirements. The control of the electronic management of data is accomplished in accordance with the methods specified in Reference 1, Section 10. AP-3.124, ''Design Calculations and Analysis'' (Ref. 2), is used to develop and document the calculation.

  20. A review of materials for spectral design coatings in signature management applications

    NASA Astrophysics Data System (ADS)

    Andersson, Kent E.; Škerlind, Christina

    2014-10-01

    The current focus in Swedish policy towards national security and high-end technical systems, together with a rapid development in multispectral sensor technology, adds to the utility of developing advanced materials for spectral design in signature management applications. A literature study was performed probing research databases for advancements. Qualitative text analysis was performed using a six-indicator instrument: spectrally selective reflectance; low gloss; low degree of polarization; low infrared emissivity; non-destructive properties in radar and in general controllability of optical properties. Trends are identified and the most interesting materials and coating designs are presented with relevant performance metrics. They are sorted into categories in the order of increasing complexity: pigments and paints, one-dimensional structures, multidimensional structures (including photonic crystals), and lastly biomimic and metamaterials. The military utility of the coatings is assessed qualitatively. The need for developing a framework for assessing the military utility of incrementally increasing the performance of spectrally selective coatings is identified.

  1. Progress of valvetrain design and exhaust valve material research for automobiles

    SciTech Connect

    Sato, K.; Takagi, Y.; Saka, T.

    1997-12-31

    Demands for exhaust valve materials are influenced by fuels and valvetrain designs to comply with requirements such as: (1) Improved seat face corrosion/abrasion resistance, (2) High strength for smaller stem designs, and (3) Cost reduction. Honda has been engaged in the development of nickel-base, heat-resistant alloys meeting the demands of performance and cost since the first development of Inconel 751 in 1979. Nickel-base, heat-resistant alloys have superior high temperature strength and corrosion resistance but are quite expensive. To meet the recent increase in demand for reduced costs, the authors have reviewed the characteristics required for exhaust valve materials and developed a resource conserving, low nickel superalloy. They believe that this newly developed alloy will find increasing usage in future exhaust valves.

  2. Generalized viscoelastic designer functionally graded auxetic materials engineered/tailored for specific task performances

    NASA Astrophysics Data System (ADS)

    Hilton, Harry H.; Lee, Daniel H.; El Fouly, Abdul Rahman A.

    2008-06-01

    For arbitrary linear Kelvin model viscoelastic constitutive relations, generalized analyses based on collocation, least squares, Lagrangean multipliers, calculus of variation and inverse formulations are presented for determining viscoelastic designer material properties tailored and engineered to be best suited for specific boundary and loading conditions and their time histories. Optimum 3-D anisotropic designer materials, including auxetic viscoelastic functionally graded ones, are studied to minimize thermal stresses, creep buckling, creep rates, deflections, aero- and hydro- dynamic noise and static and dynamic aero-viscoelastic effects while concurrently lowering failure probabilities and extending structural survival times and maximizing or minimizing energy dissipation and its rate. The analyses are formulated for single structural elements as well as the entire structure. Extensions to the entire vehicle that incorporate aerodynamics, stability and control are discussed and the dimensions of computational requirements are estimated.

  3. Collection, processing, and reporting of damage tolerant design data for non-aerospace structural materials

    NASA Technical Reports Server (NTRS)

    Huber, P. D.; Gallagher, J. P.

    1994-01-01

    This report describes the organization, format and content of the NASA Johnson damage tolerant database which was created to store damage tolerant property data for non aerospace structural materials. The database is designed to store fracture toughness data (K(sub IC), K(sub c), J(sub IC) and CTOD(sub IC)), resistance curve data (K(sub R) VS. delta a (sub eff) and JR VS. delta a (sub eff)), as well as subcritical crack growth data (a vs. N and da/dN vs. delta K). The database contains complementary material property data for both stainless and alloy steels, as well as for aluminum, nickel, and titanium alloys which were not incorporated into the Damage Tolerant Design Handbook database.

  4. Space Shuttle Orbiter - Leading edge structural design/analysis and material allowables

    NASA Technical Reports Server (NTRS)

    Johnson, D. W.; Curry, D. M.; Kelly, R. E.

    1986-01-01

    Reinforced Carbon-Carbon (RCC), a structural composite whose development was targeted for the high temperature reentry environments of reusable space vehicles, has successfully demonstrated that capability on the Space Shuttle Orbiter. Unique mechanical properties, particularly at elevated temperatures up to 3000 F, make this material ideally suited for the 'hot' regions of multimission space vehicles. Design allowable characterization testing, full-scale development and qualification testing, and structural analysis techniques will be presented herein that briefly chart the history of the RCC material from infancy to eventual multimission certification for the Orbiter. Included are discussions pertaining to the development of the design allowable data base, manipulation of the test data into usable forms, and the analytical verification process.

  5. J. F. Mandell, D. D. Samborsky, and H. J. Sutherland, "Effects of Materials Parameters and Design Details on the Fatigue of Composite Materials for Wind Turbine Blades", 1999

    E-print Network

    J. F. Mandell, D. D. Samborsky, and H. J. Sutherland, "Effects of Materials Parameters and Design Turbine Blades John F. Mandell Daniel D. Samborsky Dept. of Chemical Engineering Montana State University

  6. Pre-Service Science and Technology Teachers' Efficacy Beliefs about Information and Communication Technologies (ICT) Usage and Material Design

    ERIC Educational Resources Information Center

    Bursal, Murat; Yigit, Nevzat

    2012-01-01

    In this study, a scale entitled "Information and Communication Technologies Usage and Material Design Efficacy [ICT_MDE]" is developed to investigate pre-service science and technology teachers' efficacy beliefs regarding ICT usage and Material Design and the factors impacting these beliefs. By using the validity and reliability data from 310…

  7. An Analysis of Teaching Competence in Science Teachers Involved in the Design of Context-Based Curriculum Materials

    ERIC Educational Resources Information Center

    De Putter-Smits, Lesley G. A.; Taconis, Ruurd; Jochems, Wim; Van Driel, Jan

    2012-01-01

    The committees for the current Dutch context-based innovation in secondary science education employed teachers to design context-based curriculum materials. A study on the learning of science teachers in design teams for context-based curriculum materials is presented in this paper. In a correlation study, teachers with (n = 5 and 840 students)…

  8. On the role of characterization in the design of interfaces in nanoscale materials technology.

    PubMed

    Ringer, S P; Ratinac, K R

    2004-06-01

    This work reviews recent research on the design and control of interfaces in engineering nanomaterials. Four case studies are presented that demonstrate the power of a multimodal approach to the characterization of different types of interfaces. We have used a combination of conventional, high resolution, and analytical transmission electron microscopy, microbeam electron diffraction, and three-dimensional atom probe to study polymer-clay nanocomposites, turbine rotor steels used for power generation, multicomponent aluminum alloys, and nanocrystalline magnetic materials. PMID:15233850

  9. Design, fabrication and characterization of a monolithic focusing piezoceramic transducer for an anisotropic material.

    PubMed

    Souris, Fabien; Grucker, Jules; Garroum, Nabil; Leclercq, Arnaud; Isac, Jean-Michel; Dupont-Roc, Jacques; Jacquier, Philippe

    2014-06-01

    Piezoceramic transducers shaped as spherical caps are widely used to focus ultrasound waves in isotropic materials. For anisotropic materials, the sound wave surface is not spherical and the transducer surface should be adjusted to reproduce a portion of this wave surface to focus the emitted sound properly. In this article, we show how to design such a transducer and how to fabricate it in lab on a standard machine from a rod of raw piezo ceramic material. The main features of its electrical impedance response are well reproduced by a numerical model, allowing the identification of most of its vibrational modes. We finally measured the sound field emitted by such a transducer and found its focusing efficiency similar to that of spherical caps in isotropic media. PMID:24985837

  10. Three-dimensional microstructural design of woven fabric composite material by homogenization method

    SciTech Connect

    Takano, Naoki; Zako, Masaru

    1995-11-01

    The strength of woven fabric composite materials depends on the microstructural geometry. However, the conventional methods for mechanical analysis, which have been widely used so far, are insufficient because they cannot take into account for the three-dimensional microstructure. In this study, three-dimensional homogenization method is shown to be effective for the evaluations of the material constants, microscopic stresses and the strength. It has been found that the transverse stresses in the direction of lamination play an important role for the fracture of both fiber bundle and resin. Also, the effect of the mismatched lay-up on the strength has been investigated. It has well been predicted that the mismatched lay-up causes the reduction of the strength and the difference of crack initiation in the resin. These simulations give a new concept of the microstructural design of the composite materials.

  11. Preliminary Design of a Galactic Cosmic Ray Shielding Materials Testbed for the International Space Station

    NASA Technical Reports Server (NTRS)

    Gaier, James R.; Berkebile, Stephen; Sechkar, Edward A.; Panko, Scott R.

    2012-01-01

    The preliminary design of a testbed to evaluate the effectiveness of galactic cosmic ray (GCR) shielding materials, the MISSE Radiation Shielding Testbed (MRSMAT) is presented. The intent is to mount the testbed on the Materials International Space Station Experiment-X (MISSE-X) which is to be mounted on the International Space Station (ISS) in 2016. A key feature is the ability to simultaneously test nine samples, including standards, which are 5.25 cm thick. This thickness will enable most samples to have an areal density greater than 5 g/sq cm. It features a novel and compact GCR telescope which will be able to distinguish which cosmic rays have penetrated which shielding material, and will be able to evaluate the dose transmitted through the shield. The testbed could play a pivotal role in the development and qualification of new cosmic ray shielding technologies.

  12. Standardization Efforts for Mechanical Testing and Design of Advanced Ceramic Materials and Components

    NASA Technical Reports Server (NTRS)

    Salem, Jonathan A.; Jenkins, Michael G.

    2003-01-01

    Advanced aerospace systems occasionally require the use of very brittle materials such as sapphire and ultra-high temperature ceramics. Although great progress has been made in the development of methods and standards for machining, testing and design of component from these materials, additional development and dissemination of standard practices is needed. ASTM Committee C28 on Advanced Ceramics and ISO TC 206 have taken a lead role in the standardization of testing for ceramics, and recent efforts and needs in standards development by Committee C28 on Advanced Ceramics will be summarized. In some cases, the engineers, etc. involved are unaware of the latest developments, and traditional approaches applicable to other material systems are applied. Two examples of flight hardware failures that might have been prevented via education and standardization will be presented.

  13. Information management in the design of materials control and accountability systems

    SciTech Connect

    Whitty, W.J.; Markin, J.T.; Strittmatter, R.B.

    1988-01-01

    This paper presents information management methods for materials accounting systems based on experience in systems development at DOE facilities. We describe principles for the acquistion and organization of data for a materials control and accountability (MC and A) system. Many of these principles are drawn from software engineering. These include the preparation of a requirements document, a functional specification, and the application of structured analysis and design. Insufficient effort and detail to these early fundamental activities for identifying and acquiring the appropriate data cause many problems later. Failure to provide for complete acquisition of all required information leads to potentially costly revisions to the data acquisition system or to a materials accounting system that cannot complete its intended functions. Likewise, unrealistic analyses requirements can cause catastrophic problems later on. 16 refs.

  14. Mobile Pit verification system design based on passive special nuclear material verification in weapons storage facilities

    SciTech Connect

    Paul, J. N.; Chin, M. R.; Sjoden, G. E.

    2013-07-01

    A mobile 'drive by' passive radiation detection system to be applied in special nuclear materials (SNM) storage facilities for validation and compliance purposes has been designed through the use of computational modeling and new radiation detection methods. This project was the result of work over a 1 year period to create optimal design specifications to include creation of 3D models using both Monte Carlo and deterministic codes to characterize the gamma and neutron leakage out each surface of SNM-bearing canisters. Results were compared and agreement was demonstrated between both models. Container leakages were then used to determine the expected reaction rates using transport theory in the detectors when placed at varying distances from the can. A 'typical' background signature was incorporated to determine the minimum signatures versus the probability of detection to evaluate moving source protocols with collimation. This established the criteria for verification of source presence and time gating at a given vehicle speed. New methods for the passive detection of SNM were employed and shown to give reliable identification of age and material for highly enriched uranium (HEU) and weapons grade plutonium (WGPu). The finalized 'Mobile Pit Verification System' (MPVS) design demonstrated that a 'drive-by' detection system, collimated and operating at nominally 2 mph, is capable of rapidly verifying each and every weapon pit stored in regularly spaced, shelved storage containers, using completely passive gamma and neutron signatures for HEU and WGPu. This system is ready for real evaluation to demonstrate passive total material accountability in storage facilities. (authors)

  15. US/Russian affirmation process of the Russian fissile material container design

    SciTech Connect

    Glass, R.E.; Nunley, S.M.; Chalfant, G.

    1998-05-10

    The US government agreed to provide the Russian Federation with containers to support the dismantlement of Russian nuclear weapons as part of the Nunn-Lugar Cooperative Threat Reduction program. In February 1996, the ``affirmation`` of the Russian Fissile Material container design was completed. The ``affirmation`` process allowed a joint program between the Russian and US governments to proceed without the exchange of sensitive weapons specific information. The Russian Fissile Material container program is an integral part of the Cooperative Threat Reduction program wherein the US government provides assistance to the states of the Former Soviet Union for dismantlement of their nuclear stockpile. The Cooperative Threat Reduction program is managed by the US Defense Special Weapons Agency. Sandia National Laboratories was selected as the design agency and technical point of contact for the Russian Federation. The Department of Energy, which certifies containers for weapons shipments in the US, provided an independent assessment of the Sandia designed container to assure that it met the requirements of the August 31, 1993 AT-4OOR Container Requirements [Sandia National Laboratories, 1993] document which was agreed to by representatives of the US and Russian Federation. The ``affirmation`` process was undertaken in lieu of a certification process. This process was a formal review by the US Department of Energy of Sandia`s design and testing of the Russian Fissile Material container. The affirmation was intended to provide the Russian Federation with assurance that the container met the negotiated requirements including specific sections of IAEA Safety Series 6 [IAEA, 1985]. The process stopped short of a certification process that would have required weapons specific design information.

  16. Computer-Aided Design of Materials for use under High Temperature Operating Condition

    SciTech Connect

    Rajagopal, K. R.; Rao, I. J.

    2010-01-31

    The procedures in place for producing materials in order to optimize their performance with respect to creep characteristics, oxidation resistance, elevation of melting point, thermal and electrical conductivity and other thermal and electrical properties are essentially trial and error experimentation that tend to be tremendously time consuming and expensive. A computational approach has been developed that can replace the trial and error procedures in order that one can efficiently design and engineer materials based on the application in question can lead to enhanced performance of the material, significant decrease in costs and cut down the time necessary to produce such materials. The work has relevance to the design and manufacture of turbine blades operating at high operating temperature, development of armor and missiles heads; corrosion resistant tanks and containers, better conductors of electricity, and the numerous other applications that are envisaged for specially structured nanocrystalline solids. A robust thermodynamic framework is developed within which the computational approach is developed. The procedure takes into account microstructural features such as the dislocation density, lattice mismatch, stacking faults, volume fractions of inclusions, interfacial area, etc. A robust model for single crystal superalloys that takes into account the microstructure of the alloy within the context of a continuum model is developed. Having developed the model, we then implement in a computational scheme using the software ABAQUS/STANDARD. The results of the simulation are compared against experimental data in realistic geometries.

  17. Development of a design methodology for high temperature cyclic applications of materials which experience cyclic softening

    SciTech Connect

    Marriott, D.L.; Stubbins, J.F. . Dept. of Mechanical and Industrial Engineering)

    1988-12-01

    The project has as its original focus the high temperature behavior of 2.25 Cr-1 Mo steel, heat treated to produce a predominantly bainitic microstructure and the load carrying response of components made of this material. Experiments were carried out on uniform and notched specimens under both steady and cyclic loading using specially acquired electromechanical test machines. It emerged that a very important feature of mechanical behavior under the conditions of interest was the strong tendency of this material to cyclically soften, particularly at high temperature in the creep range, giving the illusion of a severe creep-fatigue interaction under certain conditions. This finding led to a significant component of the project being devoted to investigation of the effects of local, as opposed to generalized, cyclic softening, and the implications this phenomenon might have on the setting of allowable design stress limits. The format of this report is as follows: The second chapter is a review of the work carried out in approximately chronological order under the headings of work was carried out under the following: (1) 2.25 Cr 1 Mo Steel -- Elevated Temperature Fatigue and Environmental Effects; (2) Preliminary Studies of Advanced Austenitics; (3) A Uniaxial Constitutive Model for Cyclic Softening; (4) The Iso-Cyclic Stress-Strain Approach to Evaluation of Components in Cyclic Softening Materials; (5) Testing of High Temperature Austenitic Alloys; and (6) Design Methodology for Aging Materials -- Application to Cyclic Softening. 65 refs., 39 figs., 7 tabs.

  18. Conceptual design report: Nuclear materials storage facility renovation. Part 3, Supplemental information

    SciTech Connect

    1995-07-14

    The Nuclear Materials Storage Facility (NMSF) at the Los Alamos National Laboratory (LANL) was a Fiscal Year (FY) 1984 line-item project completed in 1987 that has never been operated because of major design and construction deficiencies. This renovation project, which will correct those deficiencies and allow operation of the facility, is proposed as an FY 97 line item. The mission of the project is to provide centralized intermediate and long-term storage of special nuclear materials (SNM) associated with defined LANL programmatic missions and to establish a centralized SNM shipping and receiving location for Technical Area (TA)-55 at LANL. Based on current projections, existing storage space for SNM at other locations at LANL will be loaded to capacity by approximately 2002. This will adversely affect LANUs ability to meet its mission requirements in the future. The affected missions include LANL`s weapons research, development, and testing (WRD&T) program; special materials recovery; stockpile survelliance/evaluation; advanced fuels and heat sources development and production; and safe, secure storage of existing nuclear materials inventories. The problem is further exacerbated by LANL`s inability to ship any materials offsite because of the lack of receiver sites for mate rial and regulatory issues. Correction of the current deficiencies and enhancement of the facility will provide centralized storage close to a nuclear materials processing facility. The project will enable long-term, cost-effective storage in a secure environment with reduced radiation exposure to workers, and eliminate potential exposures to the public. It is organized into seven parts. Part I - Design Concept describes the selected solution. Part III - Supplemental Information contains calculations for the various disciplines as well as other supporting information and analyses.

  19. Rational design, synthesis, purification, and activation of metal-organic framework materials.

    PubMed

    Farha, Omar K; Hupp, Joseph T

    2010-08-17

    The emergence of metal-organic frameworks (MOFs) as functional ultrahigh surface area materials is one of the most exciting recent developments in solid-state chemistry. Now constituting thousands of distinct examples, MOFs are an intriguing class of hybrid materials that exist as infinite crystalline lattices with inorganic vertices and molecular-scale organic connectors. Useful properties such as large internal surface areas, ultralow densities, and the availability of uniformly structured cavities and portals of molecular dimensions characterize functional MOFs. Researchers have effectively exploited these unusual properties in applications such as hydrogen and methane storage, chemical separations, and selective chemical catalysis. In principle, one of the most attractive features of MOFs is the simplicity of their synthesis. Typically they are obtained via one-pot solvothermal preparations. However, with the simplicity come challenges. In particular, MOF materials, especially more complex ones, can be difficult to obtain in pure form and with the optimal degree of catenation, the interpenetration or interweaving of identical independent networks. Once these two issues are satisfied, the removal of the guest molecules (solvent from synthesis) without damaging the structural integrity of the material is often an additional challenge. In this Account, we review recent advances in the synthetic design, purification, and activation of metal-organic framework materials. We describe the rational design of a series of organic struts to limit framework catenation and thereby produce large pores. In addition, we demonstrate the rapid separation of desired MOFs from crystalline and amorphous contaminants cogenerated during synthesis based on their different densities. Finally, we discuss the mild and efficient activation of initially solvent-filled pores with supercritical carbon dioxide, yielding usable channels and high internal surface areas. We expect that the advances in the synthesis, separation, and activation of metal-organic frameworks could lead to MOFs with new structures and functions, better and faster separation and purification of these materials, and processing methods that avoid pore blockage and pore collapse. PMID:20608672

  20. Comparison of design of intraocular lens versus the material for PCO prevention

    PubMed Central

    Hazra, Sarbani; Palui, Himangshu; Vemuganti, Geeta K

    2012-01-01

    AIM To evaluate the influence of different intraocular lens(IOL) designs made of PMMA on posterior capsular opacification(PCO) and compare with foldable designs. METHODS Phacoemulsification and IOL implantation was done in one eye of 24 New Zealand White rabbits, with IOL of two different designs (Square edged or round edge) and two different materials(PMMA or HEMA). After three months, the animals were sacrificed and enucleated. Evaluation of PCO included posterior view, migration of anterior capsular epithelial cells to the posterior capsule following epithelial-mesenchymal transition were assessed by staining the histological sections of posterior capsule by hematoxylin-eosin(HE) and Periodic acid- Schiff (PAS). The IOLs were extracted and stained with HE to evaluate the presence of adherent cells on the lens surface. RESULTS PCO was highest with round edged rigid lens. There was no significant difference in the PCO between the square edged PMMA and square edged foldable lens. CONCLUSION It is the design of the IOL not the material that offers protection on PCO formation. PMID:22553756

  1. High-Temperature Structures, Adhesives, and Advanced Thermal Protection Materials for Next-Generation Aeroshell Design

    NASA Technical Reports Server (NTRS)

    Collins, Timothy J.; Congdon, William M.; Smeltzer, Stanley S.; Whitley, Karen S.

    2005-01-01

    The next generation of planetary exploration vehicles will rely heavily on robust aero-assist technologies, especially those that include aerocapture. This paper provides an overview of an ongoing development program, led by NASA Langley Research Center (LaRC) and aimed at introducing high-temperature structures, adhesives, and advanced thermal protection system (TPS) materials into the aeroshell design process. The purpose of this work is to demonstrate TPS materials that can withstand the higher heating rates of NASA's next generation planetary missions, and to validate high-temperature structures and adhesives that can reduce required TPS thickness and total aeroshell mass, thus allowing for larger science payloads. The effort described consists of parallel work in several advanced aeroshell technology areas. The areas of work include high-temperature adhesives, high-temperature composite materials, advanced ablator (TPS) materials, sub-scale demonstration test articles, and aeroshell modeling and analysis. The status of screening test results for a broad selection of available higher-temperature adhesives is presented. It appears that at least one (and perhaps a few) adhesives have working temperatures ranging from 315-400 C (600-750 F), and are suitable for TPS-to-structure bondline temperatures that are significantly above the traditional allowable of 250 C (482 F). The status of mechanical testing of advanced high-temperature composite materials is also summarized. To date, these tests indicate the potential for good material performance at temperatures of at least 600 F. Application of these materials and adhesives to aeroshell systems that incorporate advanced TPS materials may reduce aeroshell TPS mass by 15% - 30%. A brief outline is given of work scheduled for completion in 2006 that will include fabrication and testing of large panels and subscale aeroshell test articles at the Solar-Tower Test Facility located at Kirtland AFB and operated by Sandia National Laboratories. These tests are designed to validate aeroshell manufacturability using advanced material systems, and to demonstrate the maintenance of bondline integrity at realistically high temperatures and heating rates. Finally, a status is given of ongoing aeroshell modeling and analysis efforts which will be used to correlate with experimental testing, and to provide a reliable means of extrapolating to performance under actual flight conditions. The modeling and analysis effort includes a parallel series of experimental tests to determine TSP thermal expansion and other mechanical properties which are required for input to the analysis models.

  2. Design, crystal growth, and physical properties of low-temperature thermoelectric materials

    NASA Astrophysics Data System (ADS)

    Fuccillo, Michael K.

    Thermoelectric materials serve as the foundation for two important modern technologies, namely 1) solid-state cooling, which enables small-area refrigeration without vibrations or moving parts, and 2) thermoelectric power generation, which has important implications for waste heat recovery and improved sources of alternative energy. Although the overall field of thermoelectrics research has been active for decades, and several consumer and industrial products have already been commercialized, the design and synthesis of new thermoelectrics that outperform long-standing state of the art materials has proven extremely challenging. This is particularly true for low-temperature refrigeration applications, which is the focus of this work; however, scientific advances in this area generally support power generation as well. In order to achieve more efficient materials for virtually all thermoelectric applications, improved materials design principles must be developed and synthetic procedures must be better understood. We aim to contribute to these goals by studying two classes of materials, namely 1) the tetradymites Bi2TeSe 2 and Bi2Te2Se, which are close relatives of state of the art thermoelectric cooling materials, and 2) Kondo insulating (-like) FeSb2 and FeSi, which possess anomalously enhanced low-temperature thermoelectric properties that arise from exotic electronic and magnetic properties. The organization of this dissertation is as follows: Chapter 1 is a brief perspective on solid-state chemistry. Chapter 2 presents experimental methods for synthesizing and characterizing thermoelectric materials. In Chapter 3, two original research projects are discussed: first, work on the tetradymite Bi2TeSe2 doped with Sb to achieve an n- to p-type transition, and second, the tetradymite Bi2Te2Se with chemical defects through two different methods. Chapter 4 gives the magnetic and transport properties of FeSb 2--RuSb2 alloys, a family of compounds exemplifying what we consider to be the next generation of thermoelectric materials for low-temperature cooling due to their anomalously enhanced low-temperature thermoelectric properties, along with an outlook for seeking additional materials with similarly enhanced properties. Lastly, in Chapter 5, a brief outlook on the future of thermoelectrics is discussed, along with our current and future work on FeSi-RuSi alloys.

  3. Design and analysis of lid closure bolts for packages used to transport radioactive materials

    SciTech Connect

    Raske, D.T.; Stojimirovic, A.

    1995-07-01

    The design criterion recommended by the U.S. Department of Energy for Category I radioactive packaging is found in Section III, Division 1, of the ASME Boiler and Pressure Vessel Code. This criterion provides material specifications and allowable stress limits for bolts used to secure lids of containment vessels. This paper describes the design requirements for Category I containment vessel lid closure bolts, and provides an example of a bolting stress analysis. The lid-closure bolting stress analysis compares calculations based on handbook formulas with an analysis performed with a finite-element computer code. The results show that the simple handbook calculations can be sufficiently accurate to evaluate the bolt stresses that occur in rotationally rigid lid flanges designed for metal-to-metal contact.

  4. The design, construction and testing of a scour monitoring system using magnetostrictive materials

    NASA Astrophysics Data System (ADS)

    Day, Steven Richard

    A system for the continuous monitoring of scour has been designed, constructed and implemented. The system detects the level of scour by attaching flow to a buried post at known depths, and detecting when individual sensors become unearthed. Two bio-inspired flow sensors were designed and constructed for use on the post. The first, resembling a seal whisker, utilized the magnetostrictive materials Alfenol and Galfenol and was optimized for >0.15m/s flow. The second, resembling seaweed, used a conventional permanent magnet and was optimized for <0.15m/s flow. A small, low powered data acquisition system was designed and constructed to monitor and record the data from the sensors. A total of four scour posts were installed at two different sites; two vertically to monitor conventional scour and two horizontally to monitor lateral riverbed migration. Data from the posts was analyzed and presented and lessons learned were documented.

  5. PREFACE: International Conference on Advanced Structural and Functional Materials Design 2008

    NASA Astrophysics Data System (ADS)

    Kakeshita, Tomoyuki

    2009-07-01

    The Ministry of Education, Culture, Sports, Science and Technology of Japan started the Priority Assistance for the Formation of Worldwide Renowned Centers of Research - Global COE Program. This program is based on the competitive principle where a third party evaluation decides which program to support and to give priority support to the formation of world-class centers of research. Our program Center of Excellence for Advanced Structural and Functional Materials Design was selected as one of 13 programs in the field of Chemistry and Materials Science. This center is composed of two materials-related Departments in the Graduate School of Engineering: Materials and Manufacturing Science and Adaptive Machine Systems, and 4 Research Institutes: Center for Atomic and Molecular Technologies, Welding and Joining Research Institute, Institute of Scientific and Industrial Research and Research Center for Ultra-High Voltage Electron Microscopy. Recently, materials research, particularly that of metallic materials, has specialized only in individual elemental characteristics and narrow specialty fields, and there is a feeling that the original role of materials research has been forgotten. The 6 educational and research organizations which make up the COE program cooperatively try to develop new advanced structural and functional materials and achieve technological breakthrough for their fabrication processes from electronic, atomic, microstructural and morphological standpoints, focusing on their design and application: development of high performance structural materials such as space plane and turbine blades operating under a severe environment, new fabrication and assembling methods for electronic devices, development of evaluation technique for materials reliability, and development of new biomaterials for regeneration of biological hard tissues. The aim of this international conference was to report the scientific progress in our Global COE program and also to discuss related research topics. The organizing committee gratefully thanks participants for presenting their recent results and for discussions with our COE members and international attendees. November 2008 Professor Tomoyuki Kakeshita Chairman of the Conference Vice Dean, Graduate School of Engineering, Osaka University, Division of Materials and Manufacturing Science, Graduate School of Engineering Leader of Global COE Program, Osaka University, ''Center of Excellence for Advanced Structural and Functional Materials Design'' Organization Chairman: T Kakeshita (Osaka University) Advisory Board:H Mehrer (University Münster, Germany), E K H Salje (University of Cambridge, United Kingdom), H-E Schaefer (University of Stuttgart, Germany), P Veyssiere (CNRS-ONERA, France) Organizing Committee: T Kakeshita, H Araki, H Fujii, S Fujimoto, Y Fujiwara, A Hirose, S Kirihara, M Mochizuki, H Mori, T Nagase, H Nakajima, T Nakano, R Nakatani, K Nogi, Y Setsuhara, Y Shiratsuchi, T Tanaka, T Terai, H Tsuchiya, N Tsuji, H Utsunomiya, H Yasuda, H Yasuda (Osaka University) Executive Committee: T Kakeshita, S Fujimoto, Y Fujiwara, A Hirose, T Tanaka, H Yasuda (Osaka University) Conference Secretariat: Y Fujiwara (Osaka University) Proceedings Editors: T Kakeshita and Y Fujiwara (Osaka University) Conference photograph

  6. Accelerated materials property predictions and design using motif-based fingerprints

    NASA Astrophysics Data System (ADS)

    Huan, Tran Doan; Mannodi-Kanakkithodi, Arun; Ramprasad, Rampi

    2015-07-01

    Data-driven approaches are particularly useful for computational materials discovery and design as they can be used for rapidly screening over a very large number of materials, thus suggesting lead candidates for further in-depth investigations. A central challenge of such approaches is to develop a numerical representation, often referred to as a fingerprint, of the materials. Inspired by recent developments in cheminformatics, we propose a class of hierarchical motif-based topological fingerprints for materials composed of elements such as C, O, H, N, F, etc., whose coordination preferences are well understood. We show that these fingerprints, when representing either molecules or crystals, may be effectively mapped onto a variety of properties using a similarity-based learning model and hence can be used to predict the relevant properties of a material, given that its fingerprint can be defined. Two simple machine-learning-based procedures are introduced to demonstrate that the learning model can be inverted to identify the desired fingerprints and then to reconstruct molecules which possess a set of targeted properties.

  7. Theoretical prediction and experimental realization of new stable inorganic materials using the inverse design approach.

    PubMed

    Zakutayev, Andriy; Zhang, Xiuwen; Nagaraja, Arpun; Yu, Liping; Lany, Stephan; Mason, Thomas O; Ginley, David S; Zunger, Alex

    2013-07-10

    Discovery of new materials is important for all fields of chemistry. Yet, existing compilations of all known ternary inorganic solids still miss many possible combinations. Here, we present an example of accelerated discovery of the missing materials using the inverse design approach, which couples predictive first-principles theoretical calculations with combinatorial and traditional experimental synthesis and characterization. The compounds in focus belong to the equiatomic (1:1:1) ABX family of ternary materials with 18 valence electrons per formula unit. Of the 45 possible V-IX-IV compounds, 29 are missing. Theoretical screening of their thermodynamic stability revealed eight new stable 1:1:1 compounds, including TaCoSn. Experimental synthesis of TaCoSn, the first ternary in the Ta-Co-Sn system, confirmed its predicted zincblende-derived crystal structure. These results demonstrate how discovery of new materials can be accelerated by the combination of high-throughput theoretical and experimental methods. Despite being made of three metallic elements, TaCoSn is predicted and explained to be a semiconductor. The band gap of this material is difficult to measure experimentally, probably due to a high concentration of interstitial cobalt defects. PMID:23672376

  8. Conceptual design report: Nuclear materials storage facility renovation. Part 6, Alternatives study

    SciTech Connect

    1995-07-14

    The Nuclear Materials Storage Facility (NMSF) at the Los Alamos National Laboratory (LANL) was a Fiscal Year (FY) 1984 line-item project completed in 1987 that has never been operated because of major design and construction deficiencies. This renovation project, which will correct those deficiencies and allow operation of the facility, is proposed as an FY 97 line item. The mission of the project is to provide centralized intermediate and long-term storage of special nuclear materials (SNM) associated with defined LANL programmatic missions and to establish a centralized SNM shipping and receiving location for Technical Area (TA)-55 at LANL. Based on current projections, existing storage space for SNM at other locations at LANL will be loaded to capacity by approximately 2002. This will adversely affect LANUs ability to meet its mission requirements in the future. The affected missions include LANL`s weapons research, development, and testing (WRD&T) program; special materials recovery; stockpile survelliance/evaluation; advanced fuels and heat sources development and production; and safe, secure storage of existing nuclear materials inventories. The problem is further exacerbated by LANL`s inability to ship any materials offsite because of the lack of receiver sites for material and regulatory issues. Correction of the current deficiencies and enhancement of the facility will provide centralized storage close to a nuclear materials processing facility. The project will enable long-term, cost-effective storage in a secure environment with reduced radiation exposure to workers, and eliminate potential exposures to the public. This report is organized according to the sections and subsections outlined by Attachment 111-2 of DOE Document AL 4700.1, Project Management System. It is organized into seven parts. This document, Part VI - Alternatives Study, presents a study of the different storage/containment options considered for NMSF.

  9. Design and evaluation of carbon nanofiber and silicon materials for neural implant applications

    NASA Astrophysics Data System (ADS)

    McKenzie, Janice L.

    Reduction of glial scar tissue around central nervous system implants is necessary for improved efficacy in chronic applications. Design of materials that possess tunable properties inspired by native biological tissue and elucidation of pertinent cellular interactions with these materials was the motivation for this study. Since nanoscale carbon fibers possess the fundamental dimensional similarities to biological tissue and have attractive material properties needed for neural biomaterial implants, this present study explored cytocompatibility of these materials as well as modifications to traditionally used silicon. On silicon materials, results indicated that nanoscale surface features reduced astrocyte functions, and could be used to guide neurite extension from PC12 cells. Similarly, it was determined that astrocyte functions (key cells in glial scar tissue formation) were reduced on smaller diameter carbon fibers (125 nm or less) while PC12 neurite extension was enhanced on smaller diameter carbon fibers (100 nm or less). Further studies implicated laminin adsorption as a key mechanism in enhancing astrocyte adhesion to larger diameter fibers and at the same time encouraging neurite extension on smaller diameter fibers. Polycarbonate urethane (PCU) was then used as a matrix material for the smaller diameter carbon fibers (100 and 60 nm). These composites proved very versatile since electrical and mechanical properties as well as cell functions and directionality could be influenced by changing bulk and surface composition and features of these matrices. When these composites were modified to be smooth at the micronscale and only rough at the nanoscale, P19 cells actually submerged philopodia, extensions, or whole cells bodies beneath the PCU in order to interact with the carbon nanofibers. These carbon nanofiber composites that have been formulated are a promising material to coat neural probes and thereby enhance functionality at the tissue interface. This improved chronic tissue interaction has the potential to reduce invasive intervention surgeries and provide sustained benefits from neural implants in patients with pathologies such as Parkinson's disease.

  10. Elementary Students' Learning of Materials Science Practices Through Instruction Based on Engineering Design Tasks

    E-print Network

    of materials, selecting appropriate materials, and describing materials' invariant, intensive properties Á Science workbooks Á Clinical interviews Á Properties of materials Objects, materials, the practice of specifying objects and materials by measurable physical properties has led to the creation

  11. 75 FR 39523 - Notice of Intent: Designation of an Ocean Dredged Material Disposal Site (ODMDS) Off the Mouth of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-09

    ... policy to prepare a voluntary National Environmental Policy document for all ODMDS designations (63 FR... AGENCY Notice of Intent: Designation of an Ocean Dredged Material Disposal Site (ODMDS) Off the Mouth of... Intent to prepare an Environmental Impact Statement (EIS) for the designation of an ODMDS off the...

  12. Soft network composite materials with deterministic and bio-inspired designs

    NASA Astrophysics Data System (ADS)

    Jang, Kyung-In; Chung, Ha Uk; Xu, Sheng; Lee, Chi Hwan; Luan, Haiwen; Jeong, Jaewoong; Cheng, Huanyu; Kim, Gwang-Tae; Han, Sang Youn; Lee, Jung Woo; Kim, Jeonghyun; Cho, Moongee; Miao, Fuxing; Yang, Yiyuan; Jung, Han Na; Flavin, Matthew; Liu, Howard; Kong, Gil Woo; Yu, Ki Jun; Rhee, Sang Il; Chung, Jeahoon; Kim, Byunggik; Kwak, Jean Won; Yun, Myoung Hee; Kim, Jin Young; Song, Young Min; Paik, Ungyu; Zhang, Yihui; Huang, Yonggang; Rogers, John A.

    2015-03-01

    Hard and soft structural composites found in biology provide inspiration for the design of advanced synthetic materials. Many examples of bio-inspired hard materials can be found in the literature; far less attention has been devoted to soft systems. Here we introduce deterministic routes to low-modulus thin film materials with stress/strain responses that can be tailored precisely to match the non-linear properties of biological tissues, with application opportunities that range from soft biomedical devices to constructs for tissue engineering. The approach combines a low-modulus matrix with an open, stretchable network as a structural reinforcement that can yield classes of composites with a wide range of desired mechanical responses, including anisotropic, spatially heterogeneous, hierarchical and self-similar designs. Demonstrative application examples in thin, skin-mounted electrophysiological sensors with mechanics precisely matched to the human epidermis and in soft, hydrogel-based vehicles for triggered drug release suggest their broad potential uses in biomedical devices.

  13. Soft network composite materials with deterministic and bio-inspired designs

    PubMed Central

    Jang, Kyung-In; Chung, Ha Uk; Xu, Sheng; Lee, Chi Hwan; Luan, Haiwen; Jeong, Jaewoong; Cheng, Huanyu; Kim, Gwang-Tae; Han, Sang Youn; Lee, Jung Woo; Kim, Jeonghyun; Cho, Moongee; Miao, Fuxing; Yang, Yiyuan; Jung, Han Na; Flavin, Matthew; Liu, Howard; Kong, Gil Woo; Yu, Ki Jun; Rhee, Sang Il; Chung, Jeahoon; Kim, Byunggik; Kwak, Jean Won; Yun, Myoung Hee; Kim, Jin Young; Song, Young Min; Paik, Ungyu; Zhang, Yihui; Huang, Yonggang; Rogers, John A.

    2015-01-01

    Hard and soft structural composites found in biology provide inspiration for the design of advanced synthetic materials. Many examples of bio-inspired hard materials can be found in the literature; far less attention has been devoted to soft systems. Here we introduce deterministic routes to low-modulus thin film materials with stress/strain responses that can be tailored precisely to match the non-linear properties of biological tissues, with application opportunities that range from soft biomedical devices to constructs for tissue engineering. The approach combines a low-modulus matrix with an open, stretchable network as a structural reinforcement that can yield classes of composites with a wide range of desired mechanical responses, including anisotropic, spatially heterogeneous, hierarchical and self-similar designs. Demonstrative application examples in thin, skin-mounted electrophysiological sensors with mechanics precisely matched to the human epidermis and in soft, hydrogel-based vehicles for triggered drug release suggest their broad potential uses in biomedical devices. PMID:25782446

  14. Rational design of metal nitride redox materials for solar-driven ammonia synthesis.

    PubMed

    Michalsky, Ronald; Pfromm, Peter H; Steinfeld, Aldo

    2015-06-01

    Fixed nitrogen is an essential chemical building block for plant and animal protein, which makes ammonia (NH3) a central component of synthetic fertilizer for the global production of food and biofuels. A global project on artificial photosynthesis may foster the development of production technologies for renewable NH3 fertilizer, hydrogen carrier and combustion fuel. This article presents an alternative path for the production of NH3 from nitrogen, water and solar energy. The process is based on a thermochemical redox cycle driven by concentrated solar process heat at 700-1200°C that yields NH3 via the oxidation of a metal nitride with water. The metal nitride is recycled via solar-driven reduction of the oxidized redox material with nitrogen at atmospheric pressure. We employ electronic structure theory for the rational high-throughput design of novel metal nitride redox materials and to show how transition-metal doping controls the formation and consumption of nitrogen vacancies in metal nitrides. We confirm experimentally that iron doping of manganese nitride increases the concentration of nitrogen vacancies compared with no doping. The experiments are rationalized through the average energy of the dopant d-states, a descriptor for the theory-based design of advanced metal nitride redox materials to produce sustainable solar thermochemical ammonia. PMID:26052421

  15. Design status and development strategy of China liquid lithium-lead blankets and related material technology

    NASA Astrophysics Data System (ADS)

    Wu, Y.; FDS Team

    2007-08-01

    A series of fusion reactors (named FDS series) have been designed and assessed in China, with four types of liquid lithium lead blankets including the RAFM steel-structured He-cooled quasi-static LiPb tritium breeder (SLL) blanket, the RAFM steel-structured He-LiPb dual-cooled (DLL) blanket, the RAFM steel-structured refractory material thermally-insulated high temperature LiPb (HTL) hydrogen production blanket and the RAFM steel or optionally the austenitic stainless steel-structured He-LiPb dual-cooled high level waste transmutation (DWT) blanket. To demonstrate and validate the feasibility of the candidate blankets for fusion energy application, the three-phases-strategy of TBM (test blanket module) development, i.e. material R&D and out-of-pile experimental mockup, EAST-TBM and ITER-TBM have been proposed. A brief overview of the four types of LiPb blanket designs and their goals are given. Material technology requirement and development strategy are also presented in this paper.

  16. Friction in modern total hip arthroplasty bearings: Effect of material, design, and test methodology.

    PubMed

    Scholl, Laura; Longaray, Jason; Raja, Lokesh; Lee, Reginald; Faizan, Ahmad; Herrera, Lizeth; Thakore, Mayur; Nevelos, Jim

    2016-01-01

    The purpose of this study was to characterize the effect of a group of variables on frictional torque generated by acetabular components as well as to understand the influence of test model. Three separate test models, which had been previously used in the literature, were used to understand the effect of polyethylene material, bearing design, head size, and material combinations. Each test model differed by the way it simulated rotation of the head, the type of frictional torque value it reported (static vs. dynamic), and the type of motion simulated (oscillating motion vs. continuous motion). It was determined that not only test model may impact product ranking of fictional torque generated but also static frictional torque may be significantly larger than a dynamic frictional torque. In addition to test model differences, it was discovered that the frictional torque values for conventional and highly cross-linked polyethylenes were not statistically significantly different in the more physiologically relevant test models. With respect to bearing design, the frictional torque values for mobile bearing designs were similar to the 28-mm diameter inner bearing rather than the large diameter outer liner. Testing with a more physiologically relevant rotation showed that frictional torque increased with bearing diameter for the metal on polyethylene and ceramic on polyethylene bearings but remained constant for ceramic on ceramic bearings. Finally, ceramic on ceramic bearings produced smaller frictional torque values when compared to metal on polyethylene and ceramic on polyethylene groups. PMID:26721426

  17. Preparation of Silicon Nitride Multilayer Ceramic Radome Material and Optimal Design of the Wall Structure

    SciTech Connect

    Chen Fei; Shen Qiang; Zhang Lianmeng

    2008-02-15

    A study of silicon nitride ceramic radomes, which includes preparation of the material and optimal design of the radome wall structure, is presented in this paper. Multilayer radome wall structure with high dielectric constant skins and a low dielectric constant core layer is used for broadband application. As a candidate material for both the skins and core layer, silicon nitride ceramics of controlled dielectric constant in the range 3.0{approx}7.5 were prepared by adding different content of sintering aids such as magnesia, alumina, silica and zirconium phosphate binder and choosing suitable sintering methods. A computer aided design (CAD) for the wall structure of silicon nitride multilayer ceramic radome based on microwave equivalent network method is carried out according to design requirements. By optimizing the thickness of skins and core layer, the power transmission efficiency of such a multilayer Si{sub 3}N{sub 4} ceramic radome is calculated. The calculated results suggest that when the dielectric constant of skins lies in the range 6{approx}7.5 and core layer in the range 3.5{approx}4, the power transmission efficiency is above 85% with frequency of 2{approx}18 GHz while the thickness of skins is less than 0.03{lambda} and the thickness ratio of skins to core layer is less than 1:15.

  18. Design for a spin-Seebeck diode based on two-dimensional materials

    NASA Astrophysics Data System (ADS)

    Fu, Hua-Hua; Wu, Dan-Dan; Gu, Lei; Wu, Menghao; Wu, Ruqian

    2015-07-01

    Studies of the spin-Seebeck effect (SSE) are very important for the development of fundamental science and novel low-power-consumption technologies. The spin-Seebeck diode (SSD), in which the spin current can be driven by a forward temperature gradient but not by a reverse temperature gradient, is a key unit in spin caloritronic devices. Here, we propose a SSD design using two-dimensional (2D) materials such as silicene and phosphorene nanoribbons as the source and drain. Due to their unique band structures and magnetic states, thermally driven spin-up and spin-down currents flow in opposite directions. This mechanism is different from that of the previous one, which uses two permalloy circular disks [Phys. Rev. Lett. 112, 047203 (2014), 10.1103/PhysRevLett.112.047203], and the SSD in our design can be easily integrated with gate voltage control. Since the concept of this design is rather general and applicable to many 2D materials, it is promising for the realization and exploitation of SSDs in nanodevices.

  19. Designing and Evaluating the Effectiveness of Physlet-Based Learning Materials in Supporting Conceptual Learning in Secondary School Physics

    NASA Astrophysics Data System (ADS)

    Ülen, Simon; ?agran, Branka; Slavinec, Mitja; Gerli?, Ivan

    2014-10-01

    Many educational researchers have investigated how best to support conceptual learning in science education. In this study, the aim was to design learning materials using Physlets, small computer simulations, and to evaluate the effectiveness of these materials in supporting conceptual learning in secondary school physics. Students were taught in two different physics courses (conditions): one group of students ( n = 40) was taught using Physlet-based learning materials, and the other ( n = 40) was taught using expository instruction. To evaluate the designed materials, we assessed students' thinking skills in relation to physics after the course and analyzed the results using an independent t test, multiple regression analyses, and one-way analysis of covariance. The results showed better thinking skills among students in the experimental group and supported a clear relationship between the physics course using Physlet-based materials and this improvement ( p < 0.05). These results indicate that properly designed Physlet-based materials can effectively support conceptual learning.

  20. Evolutionary Design of Low Molecular Weight Organic Anolyte Materials for Applications in Nonaqueous Redox Flow Batteries.

    PubMed

    Sevov, Christo S; Brooner, Rachel E M; Chénard, Etienne; Assary, Rajeev S; Moore, Jeffrey S; Rodríguez-López, Joaquín; Sanford, Melanie S

    2015-11-18

    The integration of renewable energy sources into the electric grid requires low-cost energy storage systems that mediate the variable and intermittent flux of energy associated with most renewables. Nonaqueous redox-flow batteries have emerged as a promising technology for grid-scale energy storage applications. Because the cost of the system scales with mass, the electroactive materials must have a low equivalent weight (ideally 150 g/(mol·e(-)) or less), and must function with low molecular weight supporting electrolytes such as LiBF4. However, soluble anolyte materials that undergo reversible redox processes in the presence of Li-ion supports are rare. We report the evolutionary design of a series of pyridine-based anolyte materials that exhibit up to two reversible redox couples at low potentials in the presence of Li-ion supporting electrolytes. A combination of cyclic voltammetry of anolyte candidates and independent synthesis of their corresponding charged-states was performed to rapidly screen for the most promising candidates. Results of this workflow provided evidence for possible decomposition pathways of first-generation materials and guided synthetic modifications to improve the stability of anolyte materials under the targeted conditions. This iterative process led to the identification of a promising anolyte material, N-methyl 4-acetylpyridinium tetrafluoroborate. This compound is soluble in nonaqueous solvents, is prepared in a single synthetic step, has a low equivalent weight of 111 g/(mol·e(-)), and undergoes two reversible 1e(-) reductions in the presence of LiBF4 to form reduced products that are stable over days in solution. PMID:26514666

  1. Conceptual design report: Nuclear materials storage facility renovation. Part 7, Estimate data

    SciTech Connect

    1995-07-14

    The Nuclear Materials Storage Facility (NMSF) at the Los Alamos National Laboratory (LANL) was a Fiscal Year (FY) 1984 line-item project completed in 1987 that has never been operated because of major design and construction deficiencies. This renovation project, which will correct those deficiencies and allow operation of the facility, is proposed as an FY 97 line item. The mission of the project is to provide centralized intermediate and long-term storage of special nuclear materials (SNM) associated with defined LANL programmatic missions and to establish a centralized SNM shipping and receiving location for Technical Area (TA)-55 at LANL. Based on current projections, existing storage space for SNM at other locations at LANL will be loaded to capacity by approximately 2002. This will adversely affect LANUs ability to meet its mission requirements in the future. The affected missions include LANL`s weapons research, development, and testing (WRD&T) program; special materials recovery; stockpile survelliance/evaluation; advanced fuels and heat sources development and production; and safe, secure storage of existing nuclear materials inventories. The problem is further exacerbated by LANL`s inability to ship any materials offsite because of the lack of receiver sites for mate rial and regulatory issues. Correction of the current deficiencies and enhancement of the facility will provide centralized storage close to a nuclear materials processing facility. The project will enable long-term, cost-effective storage in a secure environment with reduced radiation exposure to workers, and eliminate potential exposures to the public. This report is organized according to the sections and subsections outlined by Attachment III-2 of DOE Document AL 4700.1, Project Management System. It is organized into seven parts. This document, Part VII - Estimate Data, contains the project cost estimate information.

  2. Geomechanical Modeling to Predict Wellbore Stresses and Strains for the Design of Wellbore Seal Repair Materials

    NASA Astrophysics Data System (ADS)

    Gomez, S. P.; Sobolik, S. R.; Matteo, E. N.; Dewers, T. A.; Taha, M. R.; Stormont, J. C.

    2013-12-01

    A critical aspect of designing effective wellbore seal repair materials is predicting thermo-mechanical perturbations in local stress that can compromise seal integrity. For the DOE-NETL project 'Wellbore Seal Repair Using Nanocomposite Materials,' we are especially interested in the stress-strain history of abandoned wells, as well as changes in local pressure, stress, and temperature conditions that accompany carbon dioxide injection or brine extraction. Building on existing thermo-hydro-mechanical (THM) finite element modeling of wellbore casings subject to significant tensile and shear loads, we advance a conceptual and numerical methodology to assess responses of annulus cement and casing. Bench-scale models complement bench-top experiments of an integrated seal system in an idealized scaled wellbore mock-up being used to test candidate seal repair materials. Field scale models use the stratigraphy from a pilot CO2 injection operation to estimate the necessary mechanical properties needed for a successful repair material. We report on approaches used for adapting existing wellbore models and share preliminary results of field scale models. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. SAND Number: 2013-6241A.

  3. Using experimental design modules for process characterization in manufacturing/materials processes laboratories

    NASA Technical Reports Server (NTRS)

    Ankenman, Bruce; Ermer, Donald; Clum, James A.

    1994-01-01

    Modules dealing with statistical experimental design (SED), process modeling and improvement, and response surface methods have been developed and tested in two laboratory courses. One course was a manufacturing processes course in Mechanical Engineering and the other course was a materials processing course in Materials Science and Engineering. Each module is used as an 'experiment' in the course with the intent that subsequent course experiments will use SED methods for analysis and interpretation of data. Evaluation of the modules' effectiveness has been done by both survey questionnaires and inclusion of the module methodology in course examination questions. Results of the evaluation have been very positive. Those evaluation results and details of the modules' content and implementation are presented. The modules represent an important component for updating laboratory instruction and to provide training in quality for improved engineering practice.

  4. Computational chemistry modeling and design of photoswitchable alignment materials for optically addressable liquid crystal devices

    NASA Astrophysics Data System (ADS)

    Marshall, K. L.; Sekera, E. R.; Xiao, K.

    2015-09-01

    Photoalignment technology based on optically switchable "command surfaces" has been receiving increasing interest for liquid crystal optics and photonics device applications. Azobenzene compounds in the form of low-molar-mass, watersoluble salts deposited either directly on the substrate surface or after dispersion in a polymer binder have been almost exclusively employed for these applications, and ongoing research in the area follows a largely empirical materials design and development approach. Recent computational chemistry advances now afford unprecedented opportunities to develop predictive capabilities that will lead to new photoswitchable alignment layer materials with low switching energies, enhanced bistability, write/erase fatigue resistance, and high laser-damage thresholds. In the work described here, computational methods based on the density functional theory and time-dependent density functional theory were employed to study the impact of molecular structure on optical switching properties in photoswitchable methacrylate and acrylamide polymers functionalized with azobenzene and spiropyran pendants.

  5. Magnetoelectic multiferroic superlattices and interfaces: Designing spintronic materials from first principles

    NASA Astrophysics Data System (ADS)

    Zanolli, Zeila

    2015-03-01

    The research challenges of the near and far future in electronics focus on the quest for new materials and novel device concepts to achieve low energy consumption, increased reliability and high device density. These can be obtained by designing active elements and interconnects whose operating principle is not (only) based on the electron charge but on the spin degree of freedom of the electron. The nanoscopic size of the materials calls for atomistic and parameter free (ab initio) simulations, which have proven to be crucial in achieving the necessary accuracy and predictive power. Materials which present a coupling between ferroelectricity and magnetism, i.e. magnetoelectric (ME) multiferroics, have been proposed as fundamental building blocks for spintronic devices. However ferroelectricity and magnetism are often exclusive or weakly coupled in bulk. In this talk, we will discuss how superlattices of perovskites can be designed from first principles to achieve strongly coupled ME and, hence, achieve control the weak magnetization via an electric field. Most important, advanced epitaxial techniques allow one to actually grow such magnetoelectric superlattices. Another route to optimize spintronic devices is to exploit the unique electronic and transport properties of Carbon-based nanomaterials. The latter present spin diffusion lengths up to 100 ?m and high electron velocity. However, a large spin diffusion length comes at the price of small Spin Orbit coupling, which limits the possibility of manipulating electrons via an external applied field. Further, to achieve graphene-based devices one also needs to open its vanishing electronic gap. We use first principle techniques to show that placing graphene on a ME substrate can overcome these limitations by inducing magnetism and opening an electronic band-gap in the hybrid organic-multiferroic material. Z.Z. acknowledges EC support under the Marie-Curie IEF (PIEF-Ga-2011-300036), computational resources from the PRACE-3IP project (FP7 RI-312763) and the JARA-HPC project (jara0088) of RWTH Aachen University.

  6. Artificial spin ice: from scientific toy to material by design (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Nisoli, Cristiano; Schiffer, Peter; Gilbert, Ian

    2015-09-01

    Frustration, the presence of constraints/interactions that cannot be completely satisfied, is ubiquitous in the physical sciences as well as in life and a source of degeneracy and disorder which gives rise to new and interesting physical phenomena. In the past years a new perspective has opened in the study of frustration through the creation of artificial frustrated magnetic systems, consisting of arrays of lithographically fabricated single-domain ferromagnetic nanostructures that behave like giant Ising spins. The interactions can be controlled through their geometric properties and arrangement: The degrees of freedom of the material can be directly tuned, but also individually observed. Experimental studies have unearthed intriguing connections to the out-of-equilibrium physics of disordered systems and non-thermal "granular" materials, while revealing strong analogies to spin ice materials and their fractionalized magnetic monopole excitations, lending the enterprise a distinctly interdisciplinary flavor. In this talk we outline the more recent developments and future vistas for progress in this rapidly expanding field. We show how recent results have opened paths to new territories. Higher control, inclusive of genuine thermal ensembles have replaced the earlier and coarser methods based on magnetic agitation. Dynamical versions are now being realized, characterized in real time via PEEM, revealing statistical mechanics in action. This has lead us to afford implementation of new geometries, not found in nature, for dedicated bottom up design of desired emergent properties. Born as a scientific toy to investigate frustration-by-design, artificial spin ice might now be used to open "a path into an uncharted territory, a landscape of advanced functional materials in which topological effects on physical properties can be explored and harnessed."

  7. Design and Implementation of a Facility for Discovering New Scintillator Materials

    SciTech Connect

    Derenzo, Stephen; Derenzo, Stephen E; Boswell, Martin S.; Bourret-Courchesne, Edith; Boutchko, Rostyslav; Budinger, Thomas F.; Canning, Andrew; Hanrahan, Stephen M.; Janecek, Martin; Peng, Qiyu; Porter-Chapman, Yetta; Powell, James; Ramsey, Christopher A.; Taylor, Scott E.; Wang, Lin-Wang; Weber, Marvin J.; Wilson, David S.

    2008-04-25

    We describe the design and operation of a high-throughput facility for synthesizing thousands of inorganic crystalline samples per year and evaluating them as potential scintillation detector materials. This facility includes a robotic dispenser, arrays of automated furnaces, a dual-beam X-ray generator for diffractometery and luminescence spectroscopy, a pulsed X-ray generator for time response measurements, computer-controlled sample changers, an optical spectrometer, and a network-accessible database management system that captures all synthesis and measurement data.

  8. Multiscale Design of Advanced Materials based on Hybrid Ab Initio and Quasicontinuum Methods

    SciTech Connect

    Luskin, Mitchell

    2014-03-12

    This project united researchers from mathematics, chemistry, computer science, and engineering for the development of new multiscale methods for the design of materials. Our approach was highly interdisciplinary, but it had two unifying themes: first, we utilized modern mathematical ideas about change-of-scale and state-of-the-art numerical analysis to develop computational methods and codes to solve real multiscale problems of DOE interest; and, second, we took very seriously the need for quantum mechanics-based atomistic forces, and based our methods on fast solvers of chemically accurate methods.

  9. Space processing of electronic materials. [determining ther themal conductivity of mercury cadmium tellurides and furnace design

    NASA Technical Reports Server (NTRS)

    Workman, G. L.; Holland, L. R.

    1981-01-01

    The relative values of thermal conductivity of solid and liquid HgCdTe are critically important in the design configuration of the furnaces used for Bridgman crystal growth. The thermal diffusivity of the material is closely linked to the conductivity by the defining relation D = k/rho c, where D is the diffusivity, K is the thermal conductivity, rho is the density, and c is the specific heat. The use of transient and periodic heating approaches to measure the diffusivity are explored. A system for securing and extracting heat from silica or glass tubes under high C vacuum conditions is described.

  10. A Multiscale, Nonlinear, Modeling Framework Enabling the Design and Analysis of Composite Materials and Structures

    NASA Technical Reports Server (NTRS)

    Bednarcyk, Brett A.; Arnold, Steven M.

    2012-01-01

    A framework for the multiscale design and analysis of composite materials and structures is presented. The ImMAC software suite, developed at NASA Glenn Research Center, embeds efficient, nonlinear micromechanics capabilities within higher scale structural analysis methods such as finite element analysis. The result is an integrated, multiscale tool that relates global loading to the constituent scale, captures nonlinearities at this scale, and homogenizes local nonlinearities to predict their effects at the structural scale. Example applications of the multiscale framework are presented for the stochastic progressive failure of a SiC/Ti composite tensile specimen and the effects of microstructural variations on the nonlinear response of woven polymer matrix composites.

  11. Design and characterization of nanowire array as thermal interface material for electronics packaging 

    E-print Network

    Chiang, Juei-Chun

    2009-05-15

    , Dennis O?Neal December 2008 Major Subject: Mechanical Engineering ` iii ABSTRACT Design and Characterization of Nanowire Array as Thermal Interface Material for Electronics Packaging. (December 2008) Juei-Chun Chiang, B.S., National Taiwan... and a heat sink. (a) without a TIM, (b) Ideal physical contacts between a CPU and a heat sink with a TIM, (c) Actual physical contacts between a CPU and a heat sink with a TIM. Figure is not drawn to scale. It is reported that as much as 99...

  12. Three-dimensional biomaterial degradation - Material choice, design and extrinsic factor considerations.

    PubMed

    Yildirimer, Lara; Seifalian, Alexander M

    2014-01-01

    The apparent difficulty to precisely control fine-tuning of biomaterial degradation has initiated the recent paradigm shift from conventional top-down fabrication methods to more nature-inspired bottom-up assemblies. Sophistication of material fabrication techniques allows today's scientists to reach beyond conventional natural materials in order to synthesise tomorrow's 'designer material'. Material degradation into smaller components and subsequent release of encapsulated cells or cell-signalling agents have opened medically exploitable avenues, transforming the area of regenerative medicine into a dynamic and self-propagating branch of modern medicine. The aim to synthesise ever more refined scaffolding structures in order to create micro- and nanoenvironments resembling those found in natural tissues now represents an ever growing niche in the materials sciences. Recently, we have developed and conducted the world's first in-human tracheal transplantation using a non-degradable completely synthetic biomaterial. Fuelled by such clinical potential, we are currently developing a biodegradable version suitable for skin tissue engineering and paediatric applications. However, despite enormous efforts, current, as yet insurmountable challenges include precise biomaterial degradation within pre-determined spatial and temporal confines in an effort to release bio-signalling agents in such orchestrated fashion as to fully regenerate functioning tissues. In this review, the authors, almost anti-climactically, ask the readers to step out of the artificially over-constructed spiral of ever more convoluted scaffold fabrication techniques and consider the benefits of controllable bottom-up scaffold fabrication methods. It will further be investigated how scaffold designs and fabrication methods may influence degradation and subsequent release of incorporated elements. A focus will be placed on the delivery of growth factors, stem cells and therapeutic agents alone or in parallel. The difficulties of designing a delivery vehicle capable of delivering multiple factors whilst maintaining distinct release kinetics will be highlighted. Finally, this review will be rounded off with an insight into current literature addressing the recurring issues of degradation product toxicities and suggests means of overcoming those. PMID:24858478

  13. Uniformity Masks Design Method Based on the Shadow Matrix for Coating Materials with Different Condensation Characteristics

    PubMed Central

    2013-01-01

    An intuitionistic method is proposed to design shadow masks to achieve thickness profile control for evaporation coating processes. The proposed method is based on the concept of the shadow matrix, which is a matrix that contains coefficients that build quantitive relations between shape parameters of masks and shadow quantities of substrate directly. By using the shadow matrix, shape parameters of shadow masks could be derived simply by solving a matrix equation. Verification experiments were performed on a special case where coating materials have different condensation characteristics. By using the designed mask pair with complementary shapes, thickness uniformities of better than 98% are demonstrated for MgF2 (m = 1) and LaF3 (m = 0.5) simultaneously on a 280?mm diameter spherical substrate with the radius curvature of 200?mm. PMID:24227996

  14. Simulation tool for optical design of PET detector modules including scintillator material and sensor array

    SciTech Connect

    Jatekos, B.; Erdei, G.; Lorincz, E.

    2011-07-01

    The appearance of single photon avalanche diodes (SPADs) in the field of PET detector modules made it necessary to apply more complex optical design methods to refine the performance of such assemblies. We developed a combined simulation tool that is capable to model complex detector structures including scintillation material, light guide, light collection optics and sensor, correctly taking into account the statistical behavior of emission of scintillation light and its absorbance in SPADs. As a validation we compared simulation results obtained by our software and another optical design program. Calculations were performed for a simple PET detector arrangement used for testing purposes. According to the results, deviation of center of gravity coordinates between the two simulations is 0.0195 mm, the average ratio of total counts 1.0052. We investigated the error resulting from finite sampling in wavelength space and we found that 20 nm pitch is sufficient for the simulation in case of the given spectral dependencies. (authors)

  15. Design of spectrally tailored fusion reactor materials experiments in the HFIR RB? capsule irradiation facility

    NASA Astrophysics Data System (ADS)

    Longest, A. W.; Corum, J. E.; Heatherly, D. W.; Thoms, K. R.

    1988-07-01

    Design of four spectrally tailored capsules to irradiate magnetic fusion energy (MFE) materials specimens in the new High Flux Isotope Reactor (HFIR) removable beryllium (RB?) facility at temperatures of 60, 200, 330 and 400°C, is described. These designs incorporate provisions for removal, examination and reencapsulation of the specimens at intermediate exposure levels en route to a target exposure level of 30 displacements per atom (dpa). With the exception of the 60°C capsule, where the test specimens are in direct contact with the reactor cooling water, the specimen temperatures (monitored by 21 thermocouples) are controlled by varying the thermal conductance of a small gap region between the specimen holder and the containment tube. Hafnium shields are used to tailor the neutron spectrum to closely match the helium production-to-atom displacement ratio ( {14 appm}/{dpa}) expected in an austenitic stainless steel fusion reactor first wall. These MFE capsule irradiations will begin in early 1988.

  16. Integrating Materials, Manufacturing, Design and Validation for Sustainability in Future Transport Systems

    NASA Astrophysics Data System (ADS)

    Price, M. A.; Murphy, A.; Butterfield, J.; McCool, R.; Fleck, R.

    2011-05-01

    The predictive methods currently used for material specification, component design and the development of manufacturing processes, need to evolve beyond the current `metal centric' state of the art, if advanced composites are to realise their potential in delivering sustainable transport solutions. There are however, significant technical challenges associated with this process. Deteriorating environmental, political, economic and social conditions across the globe have resulted in unprecedented pressures to improve the operational efficiency of the manufacturing sector generally and to change perceptions regarding the environmental credentials of transport systems in particular. There is a need to apply new technologies and develop new capabilities to ensure commercial sustainability in the face of twenty first century economic and climatic conditions as well as transport market demands. A major technology gap exists between design, analysis and manufacturing processes in both the OEMs, and the smaller companies that make up the SME based supply chain. As regulatory requirements align with environmental needs, manufacturers are increasingly responsible for the broader lifecycle aspects of vehicle performance. These include not only manufacture and supply but disposal and re-use or re-cycling. In order to make advances in the reduction of emissions coupled with improved economic efficiency through the provision of advanced lightweight vehicles, four key challenges are identified as follows: Material systems, Manufacturing systems, Integrated design methods using digital manufacturing tools and Validation systems. This paper presents a project which has been designed to address these four key issues, using at its core, a digital framework for the creation and management of key parameters related to the lifecycle performance of thermoplastic composite parts and structures. It aims to provide capability for the proposition, definition, evaluation and demonstration of advanced lightweight structures for new generation vehicles in the context of whole life performance parameters.

  17. Integrating Materials, Manufacturing, Design and Validation for Sustainability in Future Transport Systems

    SciTech Connect

    Price, M. A.; Murphy, A.; Butterfield, J.; McCool, R.; Fleck, R.

    2011-05-04

    The predictive methods currently used for material specification, component design and the development of manufacturing processes, need to evolve beyond the current 'metal centric' state of the art, if advanced composites are to realise their potential in delivering sustainable transport solutions. There are however, significant technical challenges associated with this process. Deteriorating environmental, political, economic and social conditions across the globe have resulted in unprecedented pressures to improve the operational efficiency of the manufacturing sector generally and to change perceptions regarding the environmental credentials of transport systems in particular. There is a need to apply new technologies and develop new capabilities to ensure commercial sustainability in the face of twenty first century economic and climatic conditions as well as transport market demands. A major technology gap exists between design, analysis and manufacturing processes in both the OEMs, and the smaller companies that make up the SME based supply chain. As regulatory requirements align with environmental needs, manufacturers are increasingly responsible for the broader lifecycle aspects of vehicle performance. These include not only manufacture and supply but disposal and re-use or re-cycling. In order to make advances in the reduction of emissions coupled with improved economic efficiency through the provision of advanced lightweight vehicles, four key challenges are identified as follows: Material systems, Manufacturing systems, Integrated design methods using digital manufacturing tools and Validation systems. This paper presents a project which has been designed to address these four key issues, using at its core, a digital framework for the creation and management of key parameters related to the lifecycle performance of thermoplastic composite parts and structures. It aims to provide capability for the proposition, definition, evaluation and demonstration of advanced lightweight structures for new generation vehicles in the context of whole life performance parameters.

  18. Materials, design, and modeling for bipolar/end plates in polymer electrolyte membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Kumar, Atul

    New vehicle technologies are required to improve upon conventional internal combustion engine technologies. In this regard, the development of fuel cell (polymer electrolyte membrane type) vehicles with improved efficiency and reliability seems promising. However, some technical issues exist that hinder the commercialization of this technology. One such issue is the high cost, volume, and mass of the bipolar/end plates in the polymer electrolyte membrane fuel cell (PEMFC) stack. This research, therefore, focuses on materials, design, and modeling for bipolar/end plates in PEMFC stack. Alternative materials were tested that can replace the conventionally used graphite in the PEMFC stack. With regards to these, a two-cell PEMFC stack was fabricated with SS-316 multi-parallel flow-field (MPFF) designed bipolar/end plates. The stack was run for over 1000 hours and showed no appreciable drop in performance. To enhance the understanding and for determining the effect of operating parameters in PEMFC, a single cell model was developed. The model results agree well with the experimental data. The gas flow-field in bipolar/end plates of the PEMFC was optimized with respect to channel dimensions, channel shape, flow-field design, and flow-field permeability. It was seen that lower the flow-field permeability better is the fuel cell performance. Based on this, the concept of use of metal foams in the gas flow-field was proposed. Experiments were carried out to test the feasibility of metal foams in the gas flow-field of bipolar/end plates in PEMFC stack. Three different porous materials, viz. Ni-Cr metal foam (50 P PI, pores per inch), S S-316 metal foam (20 PPI), and carbon cloth were tested, and the results were compared to the conventional MPFF channel design concept. It was seen that the performance with Ni-Cr metal foam was highest, and decreased in the order of SS-316 metal foam, conventional MPFF design, and carbon cloth. This trend was explained based on the effective permeability of the gas flow-field. Lower permeability values result in more tortuous path for the gases and consequently in an increased pressure drop which enhanced the cell performance.

  19. Design of Low Elastic Modulus Ti-Nb-Zr Alloys for Implant Materials

    NASA Astrophysics Data System (ADS)

    Song, Xiping; You, Li; Zhang, Bei; Song, Anna

    2011-06-01

    Titanium alloys are expected to be much more widely used for hard tissue implant materials due to their superior biocompatibility and high corrosion. However, the larger Young's modulus of present titanium alloys always leads to stress shielding and harmful effects on human bones and results in premature failure of the implant. Recently a d-electron alloy design method has been proposed to design low elastic modulus titanium alloys and achieve some actual results. In this paper, a series of the Ti-Nb-Zr alloys has been designed with the d-electron alloy design method, and the phase structure, lattice parameter and elastic modulus have been investigated. The results show that with the increase of /line {Bo} and /line {Md} , the lattice parameters of these alloys increase monotonously with the single phase structure of bcc ? phase. The maximum increment reaches 4.5% compared with that of matrix ? phase. As the /line {Bo} and /line {Md} increase up further, the phase structure begins to change from bcc ? phase to hcp ? phase. Correspondingly the elastic modulus decreases first and then increase, from 96.8 GPa to 67.4 GPa, and then to 83.2GPa with the increase of /line {Bo} and /line {Md} . The lattice parameter and phase structure both exhibit significant influences on the elastic modulus of these alloys.

  20. IFMIF, International Fusion Materials Irradiation Facility conceptual design activity cost report

    SciTech Connect

    Rennich, M.J.

    1996-12-01

    This report documents the cost estimate for the International Fusion Materials Irradiation Facility (IFMIF) at the completion of the Conceptual Design Activity (CDA). The estimate corresponds to the design documented in the Final IFMIF CDA Report. In order to effectively involve all the collaborating parties in the development of the estimate, a preparatory meeting was held at Oak Ridge National Laboratory in March 1996 to jointly establish guidelines to insure that the estimate was uniformly prepared while still permitting each country to use customary costing techniques. These guidelines are described in Section 4. A preliminary cost estimate was issued in July 1996 based on the results of the Second Design Integration Meeting, May 20--27, 1996 at JAERI, Tokai, Japan. This document served as the basis for the final costing and review efforts culminating in a final review during the Third IFMIF Design Integration Meeting, October 14--25, 1996, ENEA, Frascati, Italy. The present estimate is a baseline cost estimate which does not apply to a specific site. A revised cost estimate will be prepared following the assignment of both the site and all the facility responsibilities.

  1. Design and Development of a Composite Dome for Experimental Characterization of Material Permeability

    NASA Technical Reports Server (NTRS)

    Estrada, Hector; Smeltzer, Stanley S., III

    1999-01-01

    This paper presents the design and development of a carbon fiber reinforced plastic dome, including a description of the dome fabrication, method for sealing penetrations in the dome, and a summary of the planned test series. This dome will be used for the experimental permeability characterization and leakage validation of composite vessels pressurized using liquid hydrogen and liquid nitrogen at the Cryostat Test Facility at the NASA Marshall Space Flight Center (MSFC). The preliminary design of the dome was completed using membrane shell analysis. Due to the configuration of the test setup, the dome will experience some flexural stresses and stress concentrations in addition to membrane stresses. Also, a potential buckling condition exists for the dome due to external pressure during the leak testing of the cryostat facility lines. Thus, a finite element analysis was conducted to assess the overall strength and stability of the dome for each required test condition. Based on these results, additional plies of composite reinforcement material were applied to local regions on the dome to alleviate stress concentrations and limit deflections. The dome design includes a circular opening in the center for the installation of a polar boss, which introduces a geometric discontinuity that causes high stresses in the region near the hole. To attenuate these high stresses, a reinforcement system was designed using analytical and finite element analyses. The development of a low leakage polar boss system is also investigated.

  2. Advancement of Systems Designs and Key Engineering Technologies for Materials Based Hydrogen Storage

    SciTech Connect

    van Hassel, Bart A.

    2015-09-18

    UTRC lead the development of the Simulink Framework model that enables a comparison of different hydrogen storage systems on a common basis. The Simulink Framework model was disseminated on the www.HSECoE.org website that is hosted by NREL. UTRC contributed to a better understanding of the safety aspects of the proposed hydrogen storage systems. UTRC also participated in the Failure Mode and Effect Analysis of both the chemical- and the adsorbent-based hydrogen storage system during Phase 2 of the Hydrogen Storage Engineering Center of Excellence. UTRC designed a hydrogen storage system with a reversible metal hydride material in a compacted form for light-duty vehicles with a 5.6 kg H2 storage capacity, giving it a 300 miles range. It contains a heat exchanger that enables efficient cooling of the metal hydride material during hydrogen absorption in order to meet the 3.3 minute refueling time target. It has been shown through computation that the kinetics of hydrogen absorption of Ti-catalyzed NaAlH4 was ultimately limiting the rate of hydrogen absorption to 85% of the material capacity in 3.3 minutes. An inverse analysis was performed in order to determine the material property requirements in order for a metal hydride based hydrogen storage system to meet the DOE targets. Work on metal hydride storage systems was halted after the Phase 1 to Phase 2 review due to the lack of metal hydride materials with the required material properties. UTRC contributed to the design of a chemical hydrogen storage system by developing an adsorbent for removing the impurity ammonia from the hydrogen gas, by developing a system to meter the transport of Ammonia Borane (AB) powder to a thermolysis reactor, and by developing a gas-liquid-separator (GLS) for the separation of hydrogen gas from AB slurry in silicone oil. Stripping impurities from hydrogen gas is essential for a long life of the fuel cell system on board of a vehicle. Work on solid transport of AB was halted after the Phase 1 to Phase 2 review in favor of studying the slurry-form of AB as it appeared to be difficult to transport a solid form of AB through the thermolysis reactor. UTRC demonstrated the operation of a compact GLS in the laboratory at a scale that would be required for the actual automotive application. The GLS met the targets for weight and volume. UTRC also reported about the unresolved issue associated with the high vapor pressure of fluids that could be used for making a slurry-form of AB. Work on the GLS was halted after the Phase 2 to Phase 3 review as the off-board regeneration efficiency of the spent AB was below the DOE target of 60%. UTRC contributed to the design of an adsorbent-based hydrogen storage system through measurements of the thermal conductivity of a compacted form of Metal Organic Framework (MOF) number 5 and through the development and sizing of a particulate filter. Thermal conductivity is important for the design of the modular adsorbent tank insert (MATI), as developed by Oregon State University (OSU), in order to enable a rapid refueling process. Stringent hydrogen quality requirements can only be met with an efficient particulate filtration system. UTRC developed a method to size the particulate filter by taking into account the effect of the pressure drop on the hydrogen adsorption process in the tank. UTRC raised awareness about the potential use of materials-based H2 storage systems in applications outside the traditional light-duty vehicle market segment by presenting at several conferences about niche application opportunities in Unmanned Aerial Vehicles (UAV), Autonomous Underwater Vehicles (AUV), portable power and others.

  3. Rational Catalyst Design of Titanium-Silica Materials Aided by Site-Specific Titration Tools

    NASA Astrophysics Data System (ADS)

    Eaton, Todd Robert

    Silica-supported titanium materials are widely used for thermocatalytic applications such as hydroxylation of alkanes and aromatics, oxidation of alcohols and ethers, ammoximation of carbonyls, and sulfoxidations, while Ti-based materials are widely studied for photocatalytic applications such as photo-oxidation of organic substrates and photo-reduction of CO 2. However, the underlying phenomena of how to synthesize, identify, and control the active structures in these materials is not well understood because of the narrow scope of previous work. Studies of titanium-based catalysts typically focus on materials where the metal is present as either highly-dispersed Ti cations or in bulk crystalline TiO2 form, neglecting the numerous and potentially useful intermediate structures. Furthermore, these works typically focus on a single synthesis technique and rely upon bulk characterization techniques to understand the materials. Here rigorous titanium-silica synthesis-structure-function relationships are established by examining several different synthetic method and utilizing characterization techniques that enable an atomic-level understanding of the materials. The materials studied span the range from isolated Ti cations to clustered TiOx domains, polymeric TiO x domains, anatase-like 2D TiO2 domains, and 3D crystalline TiO2. Tools to quantify accessible TiO x and tetrahedral Ti sites are developed, utilizing the selective titration of titanium with phenylphosphonic acid (PPA). Catalytic properties are probed with the photocatalytic oxidation of benzyl alcohol and the thermocatalytic epoxidation of cis-cyclooctene with H2O2 . PPA titration data indicate that the rate of benzyl alcohol photo-oxidation is independent of titanium coordination, while the rate of alkene epoxidation with H2O2 is proportional to the number of tetrahedral titanium sites on the catalyst. PPA titration data also enables the estimation of TiO2 particle size and reveals an important distinction between particle and crystal size, as obtained from XRD. In the course of establishing these relationships we've gained the knowledge of how to control TiO x structure, which enables the design of new and better catalysts. Understanding the synthesis-structure-function relationships allow for the design of a tandem photo/thermocatalytic reaction system for producing and consuming H2O2. By partially overcoating a TiO 2 photocatalyst with a ˜2 nm silica layer we observe a 56-fold rate improvement compared to bare-TiO2 for H2O2 synthesis from the proton-assisted reduction of O2. Addition of metal-SiO2 thermocatalysts (metal=Ti, Nb, or Ta) with sites needed for H2O2 activation creates a tandem system wherein the H2O2 produced in situ is utilized for alkene epoxidation. Compared to a thermocatalytic-only system, the tandem system accelerates epoxidation for cis-cyclooctene(11x faster), styrene(20x) and 1-octene(30x). This approach demonstrates a means for epoxidation with O2 that avoids H2O2 purification and transport, simplifies the total process, provides new opportunities for control by independent H2O2 production and consumption in the same reactor, and enhances rates relative to thermocatalytic-only epoxidation by intimately coupling H2O2 generation and consumption. Critically, establishment of titanium-silica synthesis-structure-function relationships enables the design of new catalysts and systems that are less energy- and material-intensive, leading towards more sustainable chemistry.

  4. 75 FR 39523 - Notice of Intent: Designation of an Ocean Dredged Material Disposal Site (ODMDS) Off the Mouth of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-09

    ...an Ocean Dredged Material Disposal Site (ODMDS) Off the Mouth of the St...preferred alternative that meets EPA's site selection criteria at 40 CFR 228.5 and 228...designating an additional ocean disposal site. The existing Jacksonville...

  5. 77 FR 55144 - Ocean Dumping; Designation of Ocean Dredged Material Disposal Sites Offshore of Yaquina Bay, Oregon

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-07

    ...disposal season since its selection under Section 103 in...use as a designated site upon the effective...be disposed at the Sites. No material defined as ``waste'' under the MPRSA...be disposed at the Sites. The dredged...

  6. Design of Bioactive Organic-inorganic Hybrid Materials with Self-setting Ability

    NASA Astrophysics Data System (ADS)

    Miyazaki, T.; Machida, S.; Morita, Y.; Ishida, E.

    2011-10-01

    Paste-like materials with ability of self-setting are attractive for bone substitutes, since they can be injected from the small hole with minimized invasion to the patient. Although bone cements which set as apatite are clinically used, there is limitation on clinical applications due to their mechanical properties such as high brittleness and low fracture toughness. To overcome this problem, organic-inorganic hybrids based on a flexible polymer are attractive. We have obtained an idea for design of self-setting hybrids using polyion complex fabricated by ionic interaction of anionic and cationic polymers. We aimed at preparation of organic-inorganic hybrids exhibiting self-setting ability and bioactivity. The liquid component was prepared from cationic chitosan aqueous solution. The powder component was prepared by mixing various carrageenans with ?-tricalcium phosphate (?-TCP). The obtained cements set within 1 day. Compressive strength showed tendency to increase with increase in ?-TCP content in the powder component. The prepared cements formed the apatite in simulated body fluid within 3 days. Novel self-setting materials based on organic-inorganic hybrid can be designed utilizing ionic interaction of polysaccharide.

  7. Fracture mechanics based design for radioactive material transport packagings -- Historical review

    SciTech Connect

    Smith, J.A.; Salzbrenner, D.; Sorenson, K.; McConnell, P.

    1998-04-01

    The use of a fracture mechanics based design for the radioactive material transport (RAM) packagings has been the subject of extensive research for more than a decade. Sandia National Laboratories (SNL) has played an important role in the research and development of the application of this technology. Ductile iron has been internationally accepted as an exemplary material for the demonstration of a fracture mechanics based method of RAM packaging design and therefore is the subject of a large portion of the research discussed in this report. SNL`s extensive research and development program, funded primarily by the U. S. Department of Energy`s Office of Transportation, Energy Management and Analytical Services (EM-76) and in an auxiliary capacity, the office of Civilian Radioactive Waste Management, is summarized in this document along with a summary of the research conducted at other institutions throughout the world. In addition to the research and development work, code and standards development and regulatory positions are also discussed.

  8. Three-dimensional Dirac semimetals: Design principles and predictions of new materials

    NASA Astrophysics Data System (ADS)

    Gibson, Q. D.; Schoop, L. M.; Muechler, L.; Xie, L. S.; Hirschberger, M.; Ong, N. P.; Car, R.; Cava, R. J.

    2015-05-01

    Design principles and predictions of new three-dimensional (3D) Dirac semimetals are presented and placed in the context of currently known materials. Three different design principles are presented (cases I, II, and III), each of which yields predictions for new candidates. For case I, 3D Dirac semimetals based on charge-balanced compounds BaAgBi, SrAgBi, YbAuSb, PtBi2, and SrSn2As2 are identified as candidates. For case II, 3D Dirac semimetals in analogy to graphene, BaGa2 is identified as a candidate, and BaPt and Li2Pt are discussed. For case III, 3D Dirac semimetals based on glide planes and screw axes, TlMo3Te3 and the A Mo3X3 family, in general (A =K , Na, In, Tl; X =Se ,Te), as well as the Group IVb trihalides such as HfI3, are identified as candidates. Finally, we discuss conventional intermetallic compounds with Dirac cones and identify Cr2B as a potentially interesting material.

  9. Performance improvement in amorphous silicon based uncooled microbolometers through pixel design and materials development

    NASA Astrophysics Data System (ADS)

    Ajmera, Sameer; Brady, John; Hanson, Charles; Schimert, Tom; Syllaios, A. J.; Taylor, Michael

    2011-06-01

    Uncooled amorphous silicon microbolometers have been established as a field-worthy technology for a broad range of applications where performance and form factor are paramount, such as soldier-borne systems. Recent developments in both bolometer materials and pixel design at L-3 in the 17?m pixel node have further advanced the state-of-the-art. Increasing the a-Si material temperature coefficient of resistance (TCR) has the impact of improving NETD sensitivity without increasing thermal time constant (TTC), leading to an improvement in the NETD×TTC product. By tuning the amorphous silicon thin-film microstructure using hydrogen dilution during deposition, films with high TCR have been developed. The electrical properties of these films have been shown to be stable even after thermal cycling to temperatures greater than 300oC enabling wafer-level vacuum packaging currently performed at L-3 to reduce the size and weight of the vacuum packaged unit. Through appropriate selection of conditions during deposition, amorphous silicon of ~3.4% TCR has been integrated into the L-3 microbolometer manufacturing flow. By combining pixel design enhancements with improvements to amorphous silicon thin-film technology, L-3's amorphous silicon microbolometer technology will continue to provide the performance required to meet the needs to tomorrow's war-fighter.

  10. Peridynamics as a rigorous coarse-graining of atomistics for multiscale materials design.

    SciTech Connect

    Lehoucq, Richard B.; Aidun, John Bahram; Silling, Stewart Andrew; Sears, Mark P.; Kamm, James R.; Parks, Michael L.

    2010-09-01

    This report summarizes activities undertaken during FY08-FY10 for the LDRD Peridynamics as a Rigorous Coarse-Graining of Atomistics for Multiscale Materials Design. The goal of our project was to develop a coarse-graining of finite temperature molecular dynamics (MD) that successfully transitions from statistical mechanics to continuum mechanics. The goal of our project is to develop a coarse-graining of finite temperature molecular dynamics (MD) that successfully transitions from statistical mechanics to continuum mechanics. Our coarse-graining overcomes the intrinsic limitation of coupling atomistics with classical continuum mechanics via the FEM (finite element method), SPH (smoothed particle hydrodynamics), or MPM (material point method); namely, that classical continuum mechanics assumes a local force interaction that is incompatible with the nonlocal force model of atomistic methods. Therefore FEM, SPH, and MPM inherit this limitation. This seemingly innocuous dichotomy has far reaching consequences; for example, classical continuum mechanics cannot resolve the short wavelength behavior associated with atomistics. Other consequences include spurious forces, invalid phonon dispersion relationships, and irreconcilable descriptions/treatments of temperature. We propose a statistically based coarse-graining of atomistics via peridynamics and so develop a first of a kind mesoscopic capability to enable consistent, thermodynamically sound, atomistic-to-continuum (AtC) multiscale material simulation. Peridynamics (PD) is a microcontinuum theory that assumes nonlocal forces for describing long-range material interaction. The force interactions occurring at finite distances are naturally accounted for in PD. Moreover, PDs nonlocal force model is entirely consistent with those used by atomistics methods, in stark contrast to classical continuum mechanics. Hence, PD can be employed for mesoscopic phenomena that are beyond the realms of classical continuum mechanics and atomistic simulations, e.g., molecular dynamics and density functional theory (DFT). The latter two atomistic techniques are handicapped by the onerous length and time scales associated with simulating mesoscopic materials. Simulating such mesoscopic materials is likely to require, and greatly benefit from multiscale simulations coupling DFT, MD, PD, and explicit transient dynamic finite element methods FEM (e.g., Presto). The proposed work fills the gap needed to enable multiscale materials simulations.

  11. Design of a high-temperature experiment for evaluating advanced structural materials

    NASA Astrophysics Data System (ADS)

    Mockler, Theodore T.; Castro-Cedeno, Mario; Gladden, Herbert J.; Kaufman, Albert

    1992-08-01

    This report describes the design of an experiment for evaluating monolithic and composite material specimens in a high-temperature environment and subject to big thermal gradients. The material specimens will be exposed to aerothermal loads that correspond to thermally similar engine operating conditions. Materials evaluated in this study were monolithic nickel alloys and silicon carbide. In addition, composites such as tungsten/copper were evaluated. A facility to provide the test environment has been assembled in the Engine Research Building at the Lewis Research Center. The test section of the facility will permit both regular and Schlieren photography, thermal imaging, and laser Doppler anemometry. The test environment will be products of hydrogen-air combustion at temperatures from about 1200 F to as high as 4000 F. The test chamber pressure will vary up to 60 psia, and the free-stream flow velocity can reach Mach 0.9. The data collected will be used to validate thermal and stress analysis models of the specimen. This process of modeling, testing, and validation is expected to yield enhancements to existing analysis tools and techniques.

  12. Mechanistic Design of New Materials and Processes through Multifunctional Atomic-Scale Simulations

    NASA Astrophysics Data System (ADS)

    Sinnott, Susan

    2013-03-01

    Multifunctional systems that contain heterogeneous interfaces are ubiquitous in numerous applications, including catalysis, electronic devices, friction, and coatings. Traditionally, computational studies of these complex interfacial systems have relied on methods such as first-principles density functional theory (DFT), because of the difficulty in describing the changes in bonding environment with empirical approaches. Here, empirical, charge optimized many-body (COMB) potentials are used in classical, atomic-scale simulations to examine several model systems that involve heterogeneous material interfaces or surface reactions at size scales that are much larger than are currently tractable with traditional DFT methods.. The COMB potentials allow for dynamic charge transfer between atoms and across interfaces, and are demonstrated to describe metallic, covalent, and ionic bonding across interfaces and at surfaces. The simulations yield mechanistic insights that allow for the design of materials and optimization of process conditions for several applications, including catalysis, thin-film growth, and supported two-dimensional materials with well-defined interfacial interactions.

  13. Progress on first-principles-based materials design for hydrogen storage

    PubMed Central

    Park, Noejung; Choi, Keunsu; Hwang, Jeongwoon; Kim, Dong Wook; Kim, Dong Ok; Ihm, Jisoon

    2012-01-01

    This article briefly summarizes the research activities in the field of hydrogen storage in sorbent materials and reports our recent works and future directions for the design of such materials. Distinct features of sorption-based hydrogen storage methods are described compared with metal hydrides and complex chemical hydrides. We classify the studies of hydrogen sorbent materials in terms of two key technical issues: (i) constructing stable framework structures with high porosity, and (ii) increasing the binding affinity of hydrogen molecules to surfaces beyond the usual van der Waals interaction. The recent development of reticular chemistry is summarized as a means for addressing the first issue. Theoretical studies focus mainly on the second issue and can be grouped into three classes according to the underlying interaction mechanism: electrostatic interactions based on alkaline cations, Kubas interactions with open transition metals, and orbital interactions involving Ca and other nontransitional metals. Hierarchical computational methods to enable the theoretical predictions are explained, from ab initio studies to molecular dynamics simulations using force field parameters. We also discuss the actual delivery amount of stored hydrogen, which depends on the charging and discharging conditions. The usefulness and practical significance of the hydrogen spillover mechanism in increasing the storage capacity are presented as well. PMID:23161910

  14. Novel Solar Energy Conversion Materials by Design of Mn(II) Oxides

    SciTech Connect

    Lany, S.; Peng, H.; Ndione, P.; Zakutayev, A.; Ginley, D. S.

    2013-01-01

    Solar energy conversion materials need to fulfill simultaneously a number of requirements in regard of their band-structure, optical properties, carrier transport, and doping. Despite their desirable chemical properties, e.g., for photo-electrocatalysis, transition-metal oxides usually do not have desirable semiconducting properties. Instead, oxides with open cation d-shells are typically Mott or charge-transfer insulators with notoriously poor transport properties, resulting from large effective electron/hole masses or from carrier self-trapping. Based on the notion that the electronic structure features (p-d interaction) supporting the p-type conductivity in d10 oxides like Cu2O and CuAlO2 occurs in a similar fashion also in the d5 (high-spin) oxides, we recently studied theoretically the band-structure and transport properties of the prototypical binary d5 oxides MnO and Fe2O3 [PRB 85, 201202(R)]. We found that MnO tends to self-trap holes by forming Mn+III, whereas Fe2O3 self-traps electrons by forming Fe+II. However, the self-trapping of holes is suppressed by when Mn is tetrahedrally coordinated, which suggests specific routes to design novel solar conversion materials by considering ternary Mn(II) oxides or oxide alloys. We are presenting theory, synthesis, and initial characterization for these novel energy materials.

  15. Design of a high-temperature experiment for evaluating advanced structural materials

    NASA Technical Reports Server (NTRS)

    Mockler, Theodore T.; Castro-Cedeno, Mario; Gladden, Herbert J.; Kaufman, Albert

    1992-01-01

    This report describes the design of an experiment for evaluating monolithic and composite material specimens in a high-temperature environment and subject to big thermal gradients. The material specimens will be exposed to aerothermal loads that correspond to thermally similar engine operating conditions. Materials evaluated in this study were monolithic nickel alloys and silicon carbide. In addition, composites such as tungsten/copper were evaluated. A facility to provide the test environment has been assembled in the Engine Research Building at the Lewis Research Center. The test section of the facility will permit both regular and Schlieren photography, thermal imaging, and laser Doppler anemometry. The test environment will be products of hydrogen-air combustion at temperatures from about 1200 F to as high as 4000 F. The test chamber pressure will vary up to 60 psia, and the free-stream flow velocity can reach Mach 0.9. The data collected will be used to validate thermal and stress analysis models of the specimen. This process of modeling, testing, and validation is expected to yield enhancements to existing analysis tools and techniques.

  16. Design Issues for Using Magnetic Materials in Radiation Environments at Elevated Temperature

    NASA Technical Reports Server (NTRS)

    Bowman, Cheryl L.

    2013-01-01

    One of the challenges of designing motors and alternators for use in nuclear powered space missions is accounting for the effects of radiation. Terrestrial reactor power plants use distance and shielding to minimize radiation damage but space missions must economize volume and mass. Past studies have shown that sufficiently high radiation levels can affect the magnetic response of hard and soft magnetic materials. Theoretical models explaining the radiation-induced degradation have been proposed but not verified. This paper reviews the literature and explains the cumulative effects of temperature, magnetic-load, and radiation-level on the magnetic properties of component materials. Magnetic property degradation is very specific to alloy choice and processing history, since magnetic properties are very much entwined with specific chemistry and microstructural features. However, there is basic theoretical as well as supportive experimental evidence that the negative impact to magnetic properties will be minimal if the bulk temperature of the material is less than fifty percent of the Curie temperature, the radiation flux is low, and the demagnetization field is small. Keywords: Magnets, Permanent Magnets, Power Converters, Nuclear Electric Power Generation, Radiation Tolerance.

  17. Life Predicted in a Probabilistic Design Space for Brittle Materials With Transient Loads

    NASA Technical Reports Server (NTRS)

    Nemeth, Noel N.; Palfi, Tamas; Reh, Stefan

    2005-01-01

    Analytical techniques have progressively become more sophisticated, and now we can consider the probabilistic nature of the entire space of random input variables on the lifetime reliability of brittle structures. This was demonstrated with NASA s CARES/Life (Ceramic Analysis and Reliability Evaluation of Structures/Life) code combined with the commercially available ANSYS/Probabilistic Design System (ANSYS/PDS), a probabilistic analysis tool that is an integral part of the ANSYS finite-element analysis program. ANSYS/PDS allows probabilistic loads, component geometry, and material properties to be considered in the finite-element analysis. CARES/Life predicts the time dependent probability of failure of brittle material structures under generalized thermomechanical loading--such as that found in a turbine engine hot-section. Glenn researchers coupled ANSYS/PDS with CARES/Life to assess the effects of the stochastic variables of component geometry, loading, and material properties on the predicted life of the component for fully transient thermomechanical loading and cyclic loading.

  18. Design strategies for achieving high triplet energy electron transporting host materials for blue electrophosphorescence

    SciTech Connect

    Sapochak, Linda S.; Padmaperuma, Asanga B.; Vecchi, Paul A.; Qiao, Hong; Burrows, Paul E.

    2006-12-01

    High efficiency small molecule organic light emitting devices (OLEDs) based on light emission from an electrophosphorescent dopant dispersed in an organic host matrix are well known. Achieving blue phosphorescent OLEDs is particularly challenging because the host triplet energy should ideally be > 2.8 eV to prevent back-transfer of energy from the dopant to the host matrix resulting in loss of efficiency. A design strategy for developing new host materials with high triplet energies by using phosphine oxide (P=O) moieties as points of saturation in order to build sublimable, electron transporting host materials starting from small, wide bandgap molecular building blocks (i.e., biphenyl, phenyl, naphthalene, octafluorobiphenyl, and N-ethylcarbazole) is described. Electrophosphorescent OLEDs using the organic phosphine oxide compounds as host materials for the sky blue organometallic phosphor, iridium(III)bis(4,6-(di-fluorophenyl)-pyridinato-N,C2’) picolinate (FIrpic) give maximum external quantum efficiencies of ~ 8% and maximum luminance power efficiencies up to 25 lm/W.

  19. STRUCTURAL DESIGN CRITERIA FOR TARGET/BLANKET SYSTEM COMPONENT MATERIALS FOR THE ACCELERATOR PRODUCTION OF TRITIUM PROJECT

    SciTech Connect

    W. JOHNSON; R. RYDER; P. RITTENHOUSE

    2001-01-01

    The design of target/blanket system components for the Accelerator Production of Tritium (APT) plant is dependent on the development of materials properties data specified by the designer. These data are needed to verify that component designs are adequate. The adequacy of the data will be related to safety, performance, and economic considerations, and to other requirements that may be deemed necessary by customers and regulatory bodies. The data required may already be in existence, as in the open technical literature, or may need to be generated, as is often the case for the design of new systems operating under relatively unique conditions. The designers' starting point for design data needs is generally some form of design criteria used in conjunction with a specified set of loading conditions and associated performance requirements. Most criteria are aimed at verifying the structural adequacy of the component, and often take the form of national or international standards such as the ASME Boiler and Pressure Vessel Code (ASME B and PV Code) or the French Nuclear Structural Requirements (RCC-MR). Whether or not there are specific design data needs associated with the use of these design criteria will largely depend on the uniqueness of the conditions of operation of the component. A component designed in accordance with the ASME B and PV Code, where no unusual environmental conditions exist, will utilize well-documented, statistically-evaluated developed in conjunction with the Code, and will not be likely to have any design data needs. On the other hand, a component to be designed to operate under unique APT conditions, is likely to have significant design data needs. Such a component is also likely to require special design criteria for verification of its structural adequacy, specifically accounting for changes in materials properties which may occur during exposure in the service environment. In such a situation it is common for the design criteria and design data needs to evolve as the design progresses, operating conditions are refined, and materials characteristics in the unique environment are established. This paper develops the relationship between the designers' data needs and the structural design criteria recently adopted for the Target Blanket System of the APT. The latter, the newly-developed APT Supplemental Structural Design Requirements (APT SSDR), was patterned after the design criteria developed for the International Thermonuclear Experimental (Fusion) Reactor (ITER). A summary description of the design rules based on the APT SSDR is presented, and the impact of these rules of changes in materials properties resulting from exposure in the APT proton/neutron irradiation environment are discussed.

  20. Effects of Design Variables on User Evaluation of Printed Materials Prepared for the Expanded Nutrition Education Program in Pennsylvania.

    ERIC Educational Resources Information Center

    Hayes, Kevin G.

    A research study investigated the effects of three design variables upon user evaluations of printed materials. Three handouts dealing with refrigeration, household pests, and germs were distributed to aides and low-income families participating in the Expanded Nutrition Education Program; these materials varied with respect to type size, presence…

  1. Designing and Evaluating the Effectiveness of Physlet-Based Learning Materials in Supporting Conceptual Learning in Secondary School Physics

    ERIC Educational Resources Information Center

    Ülen, Simon; Cagran, Branka; Slavinec, Mitja; Gerlic, Ivan

    2014-01-01

    Many educational researchers have investigated how best to support conceptual learning in science education. In this study, the aim was to design learning materials using Physlets, small computer simulations, and to evaluate the effectiveness of these materials in supporting conceptual learning in secondary school physics. Students were taught in…

  2. A predictive machine learning approach for microstructure optimization and materials design

    NASA Astrophysics Data System (ADS)

    Liu, Ruoqian; Kumar, Abhishek; Chen, Zhengzhang; Agrawal, Ankit; Sundararaghavan, Veera; Choudhary, Alok

    2015-06-01

    This paper addresses an important materials engineering question: How can one identify the complete space (or as much of it as possible) of microstructures that are theoretically predicted to yield the desired combination of properties demanded by a selected application? We present a problem involving design of magnetoelastic Fe-Ga alloy microstructure for enhanced elastic, plastic and magnetostrictive properties. While theoretical models for computing properties given the microstructure are known for this alloy, inversion of these relationships to obtain microstructures that lead to desired properties is challenging, primarily due to the high dimensionality of microstructure space, multi-objective design requirement and non-uniqueness of solutions. These challenges render traditional search-based optimization methods incompetent in terms of both searching efficiency and result optimality. In this paper, a route to address these challenges using a machine learning methodology is proposed. A systematic framework consisting of random data generation, feature selection and classification algorithms is developed. Experiments with five design problems that involve identification of microstructures that satisfy both linear and nonlinear property constraints show that our framework outperforms traditional optimization methods with the average running time reduced by as much as 80% and with optimality that would not be achieved otherwise.

  3. A predictive machine learning approach for microstructure optimization and materials design.

    PubMed

    Liu, Ruoqian; Kumar, Abhishek; Chen, Zhengzhang; Agrawal, Ankit; Sundararaghavan, Veera; Choudhary, Alok

    2015-01-01

    This paper addresses an important materials engineering question: How can one identify the complete space (or as much of it as possible) of microstructures that are theoretically predicted to yield the desired combination of properties demanded by a selected application? We present a problem involving design of magnetoelastic Fe-Ga alloy microstructure for enhanced elastic, plastic and magnetostrictive properties. While theoretical models for computing properties given the microstructure are known for this alloy, inversion of these relationships to obtain microstructures that lead to desired properties is challenging, primarily due to the high dimensionality of microstructure space, multi-objective design requirement and non-uniqueness of solutions. These challenges render traditional search-based optimization methods incompetent in terms of both searching efficiency and result optimality. In this paper, a route to address these challenges using a machine learning methodology is proposed. A systematic framework consisting of random data generation, feature selection and classification algorithms is developed. Experiments with five design problems that involve identification of microstructures that satisfy both linear and nonlinear property constraints show that our framework outperforms traditional optimization methods with the average running time reduced by as much as 80% and with optimality that would not be achieved otherwise. PMID:26100717

  4. Collagen-like peptides and peptide-polymer conjugates in the design of assembled materials

    PubMed Central

    Luo, Tianzhi; Kiick, Kristi L.

    2013-01-01

    Collagen is the most abundant protein in mammals, and there has been long-standing interest in understanding and controlling collagen assembly in the design of new materials. Collagen-like peptides (CLP), also known as collagen-mimetic peptides (CMP) or collagen-related peptides (CRP), have thus been widely used to elucidate collagen triple helix structure as well as to produce higher-order structures that mimic natural collagen fibers. This mini-review provides an overview of recent progress on these topics, in three broad topical areas. The first focuses on reported developments in deciphering the chemical basis for collagen triple helix stabilization, which we review not with the intent of describing the basic structure and biological function of collagen, but to summarize different pathways for designing collagen-like peptides with high thermostability. Various approaches for producing higher-order structures via CLP self-assembly, via various types of intermolecular interaction, are then discussed. Finally, recent developments in a new area, the production of polymer-CLP bioconjugates, are summarized. Biological applications of collagen contained hydrogels are also included in this section. The topics may serve as a guide for the design of collagen-like peptides and their bioconjugates for targeted application in the biomedical arena. PMID:24039275

  5. Thermal and flow analyses of the Nuclear Materials Storage Facility Renovation Title I 60% design

    SciTech Connect

    Knight, T.D.; Steinke, R.G.; Mueller, C.

    1998-08-01

    The authors are continuing to use the computational fluid dynamics code CFX-4.2 to evaluate the steady-state thermal-hydraulic conditions in the Nuclear Material Storage Facility Renovation Title 1 60% Design. The analyses build on those performed for the 30% design. They have run an additional 9 cases to investigate both the performance of the passive vault and of an individual drywell. These cases investigated the effect of wind on the inlet tower, the importance of resolving boundary layers in the analyses, and modifications to the porous-medium approach used in the earlier analyses to represent better the temperature fields resulting from the detailed modeling of the boundary layers. The difference between maximum temperatures of the bulk air inside the vault for the two approaches is small. They continued the analyses of the wind effects around the inflector fixture, a canopy and cruciform device, on the inlet tower by running a case with the wind blowing diagonally across the inflector. The earlier analyses had investigated a wind that was blowing parallel to one set of vanes on the inflector. Several subcases for these analyses investigated coupling the analysis to the facility analysis and design changes for the inflector.

  6. A predictive machine learning approach for microstructure optimization and materials design

    PubMed Central

    Liu, Ruoqian; Kumar, Abhishek; Chen, Zhengzhang; Agrawal, Ankit; Sundararaghavan, Veera; Choudhary, Alok

    2015-01-01

    This paper addresses an important materials engineering question: How can one identify the complete space (or as much of it as possible) of microstructures that are theoretically predicted to yield the desired combination of properties demanded by a selected application? We present a problem involving design of magnetoelastic Fe-Ga alloy microstructure for enhanced elastic, plastic and magnetostrictive properties. While theoretical models for computing properties given the microstructure are known for this alloy, inversion of these relationships to obtain microstructures that lead to desired properties is challenging, primarily due to the high dimensionality of microstructure space, multi-objective design requirement and non-uniqueness of solutions. These challenges render traditional search-based optimization methods incompetent in terms of both searching efficiency and result optimality. In this paper, a route to address these challenges using a machine learning methodology is proposed. A systematic framework consisting of random data generation, feature selection and classification algorithms is developed. Experiments with five design problems that involve identification of microstructures that satisfy both linear and nonlinear property constraints show that our framework outperforms traditional optimization methods with the average running time reduced by as much as 80% and with optimality that would not be achieved otherwise. PMID:26100717

  7. The Effect of Applying Elements of Instructional Design on Teaching Material for the Subject of Classification of Matter

    ERIC Educational Resources Information Center

    Ozdilek, Zehra; Ozkan, Muhlis

    2009-01-01

    The aim of this study was to examine the effect of instructional materials for the subject of classification of matter as solids, liquids and gases that were developed using a holistic instructional design model on student achievement. In the study a pre-test/post-test with control group experimental design was used. The study was conducted in the…

  8. Web-Based Tools for Designing and Developing Teaching Materials for Integration of Information Technology into Instruction

    ERIC Educational Resources Information Center

    Chang, Kuo-En; Sung, Yao-Ting; Hou, Huei-Tse

    2006-01-01

    Educational software for teachers is an important, yet usually ignored, link for integrating information technology into classroom instruction. This study builds a web-based teaching material design and development system. The process in the system is divided into four stages, analysis, design, development, and practice. Eight junior high school…

  9. Development of Design Standards and Guidelines for Electromagnetic Compatibility and Lightning Protection for Spacecraft Utilizing Composite Materials

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Preliminary design guidelines necessary to assure electromagnetic compatibility (EMC) of spacecraft using composite materials, are presented. A database of electrical properties of composite materials which may have an effect on EMC is established. The guidelines concentrate on the composites that are conductive but may require enhancement to be adequate for EMC purposes. These composites are represented by graphite reinforced polymers. Methods for determining adequate conductivity levels for various EMC purposes are defined, along with the methods of design which increase conductivity of composite materials and joints to adequate levels.

  10. Investigation of lightweight designs and materials for LO2 and LH2 propellant tanks for space vehicles, phase 1

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Design, analysis, and fabrication studies were performed on nonintegral (suspended) tanks using a representative space tug design. The LH2 and LO2 tank concept selection was developed. Tank geometries and support relationships were investigated using tug design propellant inertias and ullage pressures, then compared based on total tug systems effects. The tank combinations which resulted in the maximum payload were selected. Tests were conducted on samples of membrane material which was processed in a manner simulating production tank fabrication operations to determine fabrication effects on the fracture toughness of the tank material. Fracture mechanics analyses were also performed to establish a preliminary set of allowables for initial defects.

  11. Design of Miniaturized Double-Negative Material for Specific Absorption Rate Reduction in Human Head

    PubMed Central

    Faruque, Mohammad Rashed Iqbal; Islam, Mohammad Tariqul

    2014-01-01

    In this study, a double-negative triangular metamaterial (TMM) structure, which exhibits a resounding electric response at microwave frequency, was developed by etching two concentric triangular rings of conducting materials. A finite-difference time-domain method in conjunction with the lossy-Drude model was used in this study. Simulations were performed using the CST Microwave Studio. The specific absorption rate (SAR) reduction technique is discussed, and the effects of the position of attachment, the distance, and the size of the metamaterials on the SAR reduction are explored. The performance of the double-negative TMMs in cellular phones was also measured in the cheek and the tilted positions using the COMOSAR system. The TMMs achieved a 52.28% reduction for the 10 g SAR. These results provide a guideline to determine the triangular design of metamaterials with the maximum SAR reducing effect for a mobile phone. PMID:25350398

  12. Design and material variation for an improved power output of AMTEC cells

    NASA Astrophysics Data System (ADS)

    Lodhi, M. A. K.; Daloglu, A.

    A number of design changes for improving the alkali metal thermo-electric converter (AMTEC) cell performance are investigated. In this study, both the material used in AMTEC cell and the dimensions of the cell are changed at the same time. Two different hot side temperatures, Thot=1173 K and Thot=1023 K, are tested. The condenser temperature, Tcond, is kept at 623 K. Results show that the maximum cell conversion efficiency and the maximum electrical power output take place for different cases. Comparing the PX-3A in operation at Thot=1173 K with the one proposed here, the maximum electrical power output and the maximum cell conversion efficiency increased by 43 and 44%, respectively. The corresponding values for Thot=1023 K are 46 and 48%.

  13. Neutron and Synchrotron Radiation Studies for Designer Materials, Sustainable Energy and Healthy Lives

    NASA Astrophysics Data System (ADS)

    Gibson, J. Murray

    2009-05-01

    Probably the most prolific use of large accelerators today is in the creation of bright beams of x-ray photons or neutrons. The number of scientific users of such sources in the US alone is approaching 10,000. I will describe the some of the major applications of synchrotron and neutron radiation and their impact on society. If you have AIDS, need a better IPOD or a more efficient car, or want to clean up a superfund site, you are benefitting from these accelerators. The design of new materials is becoming more and more dependent on structural information from these sources. I will identify the trends in applications which are demanding new sources with greater capabilities.

  14. Design of new disulfide-based organic compounds for the improvement of self-healing materials.

    PubMed

    Matxain, Jon M; Asua, José M; Ruipérez, Fernando

    2016-01-21

    Self-healing materials are a very promising kind of materials due to their capacity to repair themselves. Among others, diphenyl disulfide-based compounds (Ph2S2) appear to be among the best candidates to develop materials with optimum self-healing properties. However, few is known regarding both the reaction mechanism and the electronic structure that make possible such properties. In this vein, theoretical approaches are of great interest. In this work, we have carried out theoretical calculations on a wide set of different disulfide compounds, both aromatic and aliphatic, in order to elucidate the prevalent reaction mechanism and the necessary electronic conditions needed for improved self-healing properties. Two competitive mechanisms were considered, namely, the metathesis and the radical-mediated mechanism. According to our calculations, the radical-mediated mechanism is the responsible for this process. The formation of sulfenyl radicals strongly depends on the S-S bond strength, which can be modulated chemically by the use of proper derivatives. At this point, amino derivatives appear to be the most promising ones. In addition to the S-S bond strength, hydrogen bonding between disulfide chains seems to be relevant to favour the contact among disulfide units. This is crucial for the reaction to take place. The calculated hydrogen bonding energies are of the same order of magnitude as the S-S bond energies. Finally, reaction barriers have been analysed for some promising candidates. Two reaction mechanisms were compared, namely, the [2+2] metathesis reaction mechanism and the [2+1] radical-mediated mechanism. No computational evidence for the existence of any transition state for the metathesis mechanism was found, which indicates that the radical-mediated mechanism is the one responsible in the self-healing process of these materials. Interestingly, the calculated reaction barriers are around 10 kcal mol(-1) regardless the substituent employed. All these results suggest that the radical formation and the structural role of the hydrogen bonding prevale over kinetics. Having this in mind, as a conclusion, some new compounds are proposed for the design of future self-healing materials with improved features. PMID:26675660

  15. Design and production of functionalized biopolyesters by Methylobacterium extorquens ATCC 55366: Toward new tissue engineering materials

    NASA Astrophysics Data System (ADS)

    Hoefer, Heinrich Friedrich Philipp Till Nikolaus

    Vascular networks are required to support the formation and function of three-dimensional tissues. Biodegradable scaffolds are being considered in order to promote vascularization where natural regeneration of lost or destroyed vascular networks fails. Particularly; composite materials are expected to fulfill the complex demands of a patient's body to support wound healing. Microbial biopolyesters are being regarded as such second and third generation biomaterials. Methylobacterium extorquens is one of several microorganisms that should be considered for the production of advanced polyhydroxyalkanoates (PHAs). M. extorquens displays a distinct advantage in that it is able to utilize methanol as an inexpensive substrate for growth and biopolyester production. The design of functionalized PHAs, which would be made of both saturated short-chain-length (scl, C ? 5) and unsaturated medium-chain-length (mcl, 6 ? C ? 14) monomeric units, aimed at combining desirable material properties of inert scl/mcl-PHAs with those of functionalized mcl-PHAs. By independently inserting the phaC1 or the phaC2 gene from Pseudomonas fluorescens GK13, recombinant M. extorquens strains were obtained which were capable of producing PHAs containing C-C double bonds. A fermentation process was developed to obtain gram quantities of biopolyesters employing the recombinant M. extorquens ATCC 55366 strain which harbored the phaC2 gene of P. fluorescens GK13, the better one of the two strains at incorporating unsaturated monomeric units. The PHAs produced were found in a blend of scl-PHAs and functionalized scl/mcl-PHAs (4 ? C ? 6), which were the products of the native and of the recombinant PHA synthase, respectively. Thermo-mechanical analysis confirmed that the functionalized scl/mcl-PHAs exhibited the desirable material properties expected. This project contributed to current research on polyhydroxyalkanoates at different levels. The terminal double bonds of the functionalized scl/mcl-PHAs are amenable to chemical modifications and could be transformed into reactive functional groups for covalently linking other biomacromolecules. It is anticipated that these biopolyesters will be utilized as tissue engineering materials in the future, due to their functionality and thermo-mechanical properties. Keywords: biopolyesters, functionalized polyhydroxyalkanoates, Methylobacterium extorquens, genetic modification, fermentation in pilot-scale operators, material characterization, thermo-mechanical properties, tissue engineering

  16. Designing an embedded probe for hazardous material shelf-life monitoring

    NASA Astrophysics Data System (ADS)

    Gordon, Grant A.; McClintic, Katherine T.; Holder, A. G.; Babich, Gregory A.

    1999-05-01

    Navy administrators estimate that hundreds of tons of hazardous material (HAZMAT) are being wastefully discarded due to premature disposal. Currently, HAZMAT items are coded when they are brought into the DoD supply system to indicate their storage lifetime. However, this process has come under criticism for generating shelf life codes that are too conservative and can not account for the varying storage conditions experienced by an individual item. Naturally, a detailed laboratory examination could determine when an time has reached the end of its useful shelf life, but this logistically clumsy approach is rarely undertaken, and thus HAZMAT is wastefully discarded. An ideal inspection method would be fast, reliable and non-invasive. We have investigated the development and use of an inexpensive nondestructive sensor to actively assess the shelf state of a ubiquitous HAZMAT, Silicon Alkyd Haze Gray paint. A simple sensor was designed to measure six features of the paint: ultrasonic velocity and attenuation, electric mobility and polarization and temperature and thermal diffusivity. To simulate the storage environment, an accelerated environmental degradation procedure was implemented to force the paint along realistic and prominent failure modes. During this degradation process, the material was monitored with the sensor and a set of standard laboratory measurement techniques. Pattern recognition techniques were applied to identify key characteristics of the data and to design a classifier to discriminate between different classes of the aged samples. Issues of sensitivity, uniqueness and indeterminacy in the problem were considered. Based on these results, a prototype sensor for shelf life management of hazardous silicon alkyd paint appears to be promising.

  17. Designing materials for energy storage with high power and energy density : LiFePO? cathode material

    E-print Network

    Kang, Byoungwoo

    2010-01-01

    LiFePO? has drawn a lot of attention as a cathode material in lithium rechargeable batteries because its structural and thermal stability, its inexpensive cost, and environmental friendliness meet the requirements of power ...

  18. Novel biocompatible polymeric blends for bone regeneration: Material and matrix design and development

    NASA Astrophysics Data System (ADS)

    Deng, Meng

    The first part of the work presented in this dissertation is focused on the design and development of novel miscible and biocompatible polyphosphazene-polyester blends as candidate materials for scaffold-based bone tissue engineering applications. Biodegradable polyesters such as poly(lactide-co-glycolide) (PLAGA) are among the most widely used polymeric materials for bone tissue engineering. However, acidic degradation products resulting from the bulk degradation mechanism often lead to catastrophic failure of the structure integrity, and adversely affect biocompatibility both in vitro and in vivo. One promising approach to circumvent these limitations is to blend PLAGA with other macromolecules that can buffer the acidic degradation products with a controlled degradation rate. Biodegradable polyphosphazenes (PPHOS), a new class of biomedical materials, have proved to be superior candidate materials to achieve this objective due to their unique buffering degradation products. A highly practical blending approach was adopted to develop novel biocompatible, miscible blends of these two polymers. In order to achieve this miscibility, a series of amino acid ester, alkoxy, aryloxy, and dipeptide substituted PPHOS were synthesized to promote hydrogen bonding interactions with PLAGA. Five mixed-substituent PPHOS compositions were designed and blended with PLAGA at different weight ratios producing candidate blends via a mutual solvent method. Preliminary characterization identified two specific side groups namely glycylglycine dipeptide and phenylphenoxy that resulted in improved blend miscibility and enhanced in vitro osteocompatibility. These findings led to the synthesis of a mixed-substituent polyphosphazene poly[(glycine ethyl glycinato)1(phenylphenoxy)1phosphazene] (PNGEGPhPh) for blending with PLAGA. Two dipeptide-based blends having weight ratios of PNGEGPhPh to PLAGA namely 25:75 (Matrix1) and 50:50 (Matrix2) were fabricated. Both of the blends were characterized for miscibility, mechanical properties, degradation kinetics, and in vitro osteocompatibility. Primary rat osteoblasts (PRO) isolated from rat calvaria were used to evaluate their in vitro osteocompatibility. The blends were also characterized for in vivo biodegradability and biocompatibility using a rat subcutaneous implantation model. Successful in vivo scaffold-based tissue regeneration greatly depends on the scaffold material biocompatibility, mechanical stability, and scaffold architecture to promote tissue in-growth. The other part of the work in the dissertation is focused on the development of mechanically competent bioresorbable nano-structured three-dimensional (3D) hiomimetic scaffolds for bone tissue engineering applications. Scaffold material selection was based on achieving improved mechanical stability, in vitro osteoblast performance, and in vivo biocompatibility. A miscible PNGEGPhPh-PLAGA blend system developed and characterized in the first part of the thesis work was chosen to fabricate a nanofiber-based mechanically competent biomimetic scaffold via electrospinning. Due to its versatility, controllability and reproducibility, the technique of electrospinning was adopted to produce blend nanofibers. The polymer solution concentration and electrospinning parameters were optimized to produce blend fibers in the range of 50-500 nm to mimic dimensions of collagen fibrils present in the natural extracellular matrix of native bone. These blend nanofiber matrices supported PRO adhesion, proliferation and showed an elevated phenotype expression compared to PLAGA nanofibers. Orienting electrospun nanofibers in a concentric manner with an open central cavity created a mechanically competent 3D scaffold mimicking the bone marrow cavity, as well as, the lamellar structure of bone. The 3D biomimetic scaffold exhibited a similar characteristic mechanical behavior to that of native bone. Compressive modulus of the scaffold was found to be within the range of human trabecular bone. To our knowledge this is the first mechanically competent 3D electrospun n

  19. Evaluations of candidate encapsulation designs and materials for low-cost silicon photovoltaic arrays

    NASA Technical Reports Server (NTRS)

    Gaines, G. B.; Carmichael, D. C.; Sliemers, F. A.; Brockway, M. C.; Bunk, A. R.; Nance, G. P.

    1978-01-01

    Three encapsulation designs for silicon photovoltaic arrays based on cells with silk-screened Ag metallization have been evaluated: transparent polymeric coatings over cells laminated between two films or sheets of polymeric materials; cells adhesively bonded to a glass cover with a polymer pottant and a glass or other substrate component. Silicone and acrylic coatings were assessed, together with acrylic sheet, 0.635 mm fiberglass-reinforced polyester sheet, 0.102 mm polycarbonate/acrylic dual-layer film, 0.127 mm fluorocarbon film, soda-lime glass, borosilicate glass, low-iron glass, and several adhesives. The encapsulation materials were characterized by light transmittance measurements, determination of moisture barrier properties and bond strengths, and by the performance of cells before and after encapsulation. Silicon and acrylic coatings provided inadequate protection. Acrylic and fluorocarbon films displayed good weatherability and acceptable optical transmittance. Borosilicate, low-iron and soda-lime-float glasses were found to be acceptable candidate encapsulants for most environments.

  20. Functional design criteria for the Hazardous Materials Management and Emergency Response (HAMMER) Training Center. Revision 1

    SciTech Connect

    Sato, P.K.

    1995-03-10

    Within the United States, there are few hands-on training centers capable of providing integrated technical training within a practical application environment. Currently, there are no training facilities that offer both radioactive and chemical hazardous response training. There are no hands-on training centers that provide training for both hazardous material operations and emergency response that also operate as a partnership between organized labor, state agencies, tribes, and local emergency responders within the US Department of Energy (DOE) complex. Available facilities appear grossly inadequate for training the thousands of people at Hanford, and throughout the Pacific Northwest, who are required to qualify under nationally-mandated requirements. It is estimated that 4,000 workers at the Hanford Site alone need hands-on training. Throughout the Pacific Northwest, the potential target audience would be over 30,000 public sector emergency response personnel, as well as another 10,000 clean-up workers represented by organized labor. The HAMMER Training Center will be an interagency-sponsored training center. It will be designed, built, and operated to ensure that clean-up workers, fire fighters, and public sector management and emergency response personnel are trained to handle accidental spills of hazardous materials. Training will cover wastes at clean-up sites, and in jurisdictions along the transportation corridors, to effectively protect human life, property, and the environment.