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1

Design and applications of negative index metamaterials  

NASA Astrophysics Data System (ADS)

Electromagnetic Negative Index Metamaterials (NIM) exhibit many novel phenomena such as negative Snell's law, backward wave propagation, reverse Cerenkov radiation, and reverse Doppler effect. Predicted theoretically by Veselago in 1968 and experimentally demonstrated and verified barely a decade ago, it has enabled many proof-of-concept applications not achievable with ordinary materials. However, from a practical perspective, synthesis issues such as material designs and fabrication techniques need to be improved for NIM to be useful. The goal of this work is to investigate and realize the practical potentials of NIM. To achieve this goal, the physical properties of NIM and their implications are reviewed to establish a fundamental theoretical understanding and appreciation. Experimentally, the constituent unit cells that make possible the realization of NIM are described. Unit cell simulation, fabrication, testing, and material properties extraction techniques and tools are developed to form the basic building blocks. In addition to being able to achieve negative index of refractions, NIM can be used to realize a continuum of material values with independent control of elect is permittivity and magnetic permeability. This newly found capability enables the development of the related field of transformation optics. An electromagnetic cloaking device, one of the first major proof-of-concept devices only made possible by the advent of NIM and transformation optics is simulated to demonstrate NIM's versatility. A major effort of this work is the design, fabrication, and testing of a NIM lens to scan phased-array antenna beams to the horizon. Lens design and optimization tools are developed, and the transformation optics technique of conformal mapping is used to transform the lens from a curved geometry to a faceted buckyball shell for easier fabrication. Other NIM applications also investigated are coated dielectric spheres for isotropic NIM unit cells, flat gradient index lenses, waveguide bandpass and bandstop filters, and a microstrip line bandstop filter. Finally, inspired by electromagnetic NIM, acoustic NIM has became a hot research topic in the last couple of years. The fundamentals of acoustic NIM and material synthesis are briefly reviewed. Potential applications in acoustic cloaking, noise cancellation and vibration damping are presented.

Lam, Tai Anh

2

Material parameter retrieval procedure for general bi-isotropic metamaterials and its application to optical chiral negative-index metamaterial design.  

PubMed

A chiral optical negative-index metamaterial design of doubly periodic construction for the near-infrared spectrum is presented. The chirality is realized by incorporating sub-wavelength planar silver-aluminasilver resonators and arranging them in a left-handed helical (i.e., stair-step) configuration as a wave propagates through the metamaterial. An effective material parameter retrieval procedure is developed for general bi-isotropic metamaterials. A numerical design example is presented and the retrieved effective material parameters exhibiting a negative index of refraction are provided. PMID:18679454

Kwon, Do-Hoon; Werner, Douglas H; Kildishev, Alexander V; Shalaev, Vladimir M

2008-08-01

3

Material parameter retrieval procedure for general bi-isotropic metamaterials and its application to optical chiral negative-index metamaterial design  

Microsoft Academic Search

A chiral optical negative-index metamaterial design of doubly periodic construction for the near-infrared spectrum is presented. The chirality is realized by incorporating sub-wavelength planar silver-aluminasilver resonators and arranging them in a left-handed helical (i.e., stair-step) configuration as a wave propagates through the metamaterial. An effective material parameter retrieval procedure is developed for general bi-isotropic metamaterials. A numerical design example is

Do-Hoon Kwon; Douglas H. Werner; Alexander V. Kildishev; Vladimir M. Shalaev

2008-01-01

4

Discontinuous design of negative index metamaterials based on mode hybridization  

E-print Network

Discontinuous design of negative index metamaterials based on mode hybridization Nian-Hai Shen, Lei (2012) Analytical modeling of conformal mantle cloaks for cylindrical objects using sub://apl.aip.org/authors #12;Discontinuous design of negative index metamaterials based on mode hybridization Nian-Hai Shen,1,a

5

Propagation of electromagnetic solitons in nonlinear negative-index materials  

Microsoft Academic Search

The propagation property of electromagnetic solitons in the negative-index material with a nonlinear polarization is investigated numerically. The role of the negative self-steepening and the higher-order nonlinear dispersion effects, which are resulted from the dispersive permeability of negative-index material, in soliton propagation is identified. It is shown that, like the positive self-steepening effect, the negative self-steepening effect also leads to

Xiaoyan Song; Shuangchun Wen

2006-01-01

6

Design-related losses of double-fishnet negative-index photonic metamaterials  

E-print Network

Design-related losses of double-fishnet negative-index photonic metamaterials G. Dolling1, M on the performance, especially on the losses, of negative-index metamaterials on the basis of the so-called double.9999) Metamaterials References and links 1. V. M. Shalaev, "Optical negative-index metamaterials," Nature Photon. 1

7

Creating double negative index materials using the Babinet principle with one metasurface  

E-print Network

Metamaterials are patterned metallic structures which permit access to a novel electromagnetic response, negative index of refraction, impossible to achieve with naturally occurring materials. Using the Babinet principle, the complementary split ring resonator (SRR) is etched in a metallic plate to provide negative \\epsilon, with perpendicular direction. Here we propose a new design, etched in a metallic plate to provide negative magnetic permeability \\mu, with perpendicular direction. The combined electromagnetic response of this planar metamaterial, where the negative \\mu comes from the aperture and the negative \\epsilon from the remainder of the continuous metallic plate, allows achievement of a double negative index metamaterial (NIM) with only one metasurface and strong transmission. These designs can be used to fabricate NIMs at microwave and optical wavelengths and three-dimensional metamaterials.

Zhang, Lei; Soukoulis, Costas M; 10.1103/PhysRevB.87.045101

2013-01-01

8

Stability criterion for Gaussian pulse propagation through negative index materials  

SciTech Connect

We analyze the dynamics of propagation of a Gaussian light pulse through a medium having a negative index of refraction employing the recently reported projection operator technique. The governing modified nonlinear Schroedinger equation, obtained by taking into account the Drude dispersive model, is expressed in terms of the parameters of Gaussian pulse, called collective variables, such as width, amplitude, chirp, and phase. This approach yields a system of ordinary differential equations for the evolution of all the pulse parameters. We demonstrate the dependence of stability of the fixed-point solutions of these ordinary differential equations on the linear and nonlinear dispersion parameters. In addition, we validate the analytical approach numerically utilizing the method of split-step Fourier transform.

Joseph, Ancemma; Porsezian, K. [Department of Physics, School of Physical, Chemical and Applied Sciences, Pondicherry University, Pondicherry 605 014 (India)

2010-02-15

9

On the resolution of lenses made of a negative-index material  

SciTech Connect

Resolution of the lenses made of a negative-index material is considered. It is shown that the super-resolution concept is untenable and the possibility of obtaining a perfect image on its own eventually contradicts Maxwell's equations in vacuum. It is also shown that known limitations of the diffraction theory on resolution of optical instruments hold true for the resolution of lenses of a negative-index material, in particular, the resolution of a Veselago lens. (nanogradient dielectric coatings and metamaterials)

Petrin, A B [Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow (Russian Federation)

2013-09-30

10

Smith-Purcell radiation from a grating of negative-index material  

NASA Astrophysics Data System (ADS)

Smith-Purcell radiation from an electric line charge that moves, at constant speed, parallel to a grating made of metamaterial with negative index is analyzed. Through theoretical analysis and computations, we show that the Smith-Purcell radiation is stronger from a grating of negative-index material, than that from a positive-index material and perfect conductor. Also, we found that the radiation strongly depends on the values of permeability and permittivity. Calculations on grating with saw-like profile and rectangular profile are also carried out and demonstrated.

Li, D.; Hangyo, M.; Yang, Z.; Asakawa, M. R.; Miyamoto, S.; Tsunawaki, Y.; Takano, K.; Imasaki, K.

2011-05-01

11

Negative Index Materials: The Key to "White" Multilayer Fabry-Perot  

E-print Network

The use of negative index materials is highly efficient for tayloring the spectral dispersion properties of a quarter-wavelength Bragg mirror and for obtaining a resonant behavior of a multilayer Fabry-Perot cavity over a very large spectral range. An optimization method is proposed and validated on some first promising devices.

Lequime, Michel; Guenneau, Sebastien; Zerrad, Myriam; Amra, Claude

2013-01-01

12

Realization of 3D Isotropic Negative Index Materials using Massively Parallel and Manufacturable Microfabrication and Micromachining Technology  

E-print Network

Realization of 3D Isotropic Negative Index Materials using Massively Parallel and Manufacturable a method to realize a three dimensional (3D) homogeneous and isotropic negative index materials (3D grown in the research community on the "discovery" of materials that have been termed Metamaterials (MTM

Islam, M. Saif

13

A Three-Dimensionally Isotropic and Perfectly Vacuum-Impedance-Matched Negative-Index Material  

NASA Astrophysics Data System (ADS)

A new scenario for realizing a gain left-handed atomic vapor medium based on both dressed-state mixed-parity transitions (for simultaneous electric- and magnetic-dipole resonance) and incoherently-pumped population transfer (for high gain amplification) in a four-level atomic system is suggested. Dressed-state assisted simultaneous electric- and magnetic-dipole allowed transitions in such a four-level atomic system (of, e.g., neutral alkali-metal atoms such as lithium and potassium atoms) are utilized for achieving negative refractive index with impedance perfectly matched to vacuum. The attractive features of the present scenario include: i) three-dimensionally isotropic negative indices; ii) incoherent-gain wave amplification; iii) perfect impedance matching to vacuum. All these important properties of the double-negative medium would have potential applications in designing some optical and photonic devices, including particularly subwavelength focusing system and negative-index superlens for perfect imaging.

Shen, Jian Qi

2014-12-01

14

NEGATIVE INDEX MATERIALS J. A. Rogers, D. Chanda, and co-workers use a  

E-print Network

technique to fabricate large-area visible 3D negative index metamaterials. Alternating silver and dielectric- wire pairs and dielectric-metal multilayers in open mesh (i.e. fishnet) layouts. This last geometry) and visible wavelengths, but is also compatible with large area fabrication strategies based on nanotransfer

Rogers, John A.

15

Optical Chiral Negative-Index Metamaterial Design Do-Hoon Kwon*1, Douglas H. Werner1, Alexander V. Kildishev2,  

E-print Network

Optical Chiral Negative-Index Metamaterial Design Do-Hoon Kwon*1, Douglas H. Werner1, Alexander V configuration that cannot be brought into congruence with its own mirror image. Isotropic chiral media are a subset of the general bi-isotropic (BI) media, for which the constitutive relations among electromagnetic

Shalaev, Vladimir M.

16

Negative-Index Metamaterials: Going Optical  

Microsoft Academic Search

The race toward engineering metamaterials comprising of negative refractive indexes in the optical range started with the realization of negative-index materials for gigahertz frequencies six years ago. Sheer miniaturization of the gigahertz resonant structures is one approach. Alternative designs make use of localized plasmon resonant metal nanoparticles or nanoholes in metal films. Following this approach, a negative refractive index has

Thomas A. Klar; Alexander V. Kildishev; Vladimir P. Drachev; Vladimir M. Shalaev

2006-01-01

17

Modulation instability induced by cross-phase modulation in negative index materials with higher-order nonlinearity  

NASA Astrophysics Data System (ADS)

Based on the dispersive Drude model in negative index materials (NIMs), nonlinear coupled Schodinger equations are derived for two copropagating optical waves with cubic-quintic nonlinearity and modulation instabilities induced by cross-phase modulation (XMI) are studied by using standard linear stability analysis and the Drude electromagnetic model. It is shown that the quintic nonlinearity strengthens the XMI with broader XMI spectra and higher peak gain. It is found that the XMI gain is obviously larger in the region with anomalous group velocity dispersion (GVD) than that in the region with normal GVD. It is also shown that the serious XMI occurs when two optical waves propagate simultaneously in the positive refractive index region or in different refractive index regions. The work provides a theoretical basis for the extinction or utilization of XMI in the propagation of high power and high speed signals in NIMs.

Liu, Ying; Xue, Yan Ling; Yu, Chuanxi

2015-03-01

18

Negative Index Materials: New Frontiers in Optics Costas M. Soukoulis 1,2  

E-print Network

, LHMs will display unique "reversed" electromagnetic properties, as a result of an electromagnetic wave highly unusual electromagnetic properties and promise new device applications. These materials do history of the field, describes the underlying physics, and reviews the experimental and theoretical

19

PHYSICAL REVIEW B 87, 045101 (2013) Creating double negative index materials using the Babinet principle with one metasurface  

E-print Network

principle with one metasurface Lei Zhang,1,* Thomas Koschny,1 and C. M. Soukoulis1,2, 1 Ames Laboratory metallic plate, allows achievement of a double negative index metamaterial (NIM) with only one metasurface

20

Optical negative-index metamaterials  

Microsoft Academic Search

Artificially engineered metamaterials are now demonstrating unprecedented electromagnetic properties that cannot be obtained with naturally occurring materials. In particular, they provide a route to creating materials that possess a negative refractive index and offer exciting new prospects for manipulating light. This review describes the recent progress made in creating nanostructured metamaterials with a negative index at optical wavelengths, and discusses

Vladimir M. Shalaev

2006-01-01

21

Achromatic negative index lens with diffractive optics  

NASA Astrophysics Data System (ADS)

In this paper, achromatization of a negative index lens is achieved by introducing the diffractive optical elements (DOEs) into the negative index lens. The diffraction efficiency of the negative index material (NIM) DOEs is deduced based on the special propagating laws and imaging properties of negative index lenses, and the expression for microstructure height is given. As an example, an achromatic refractive–diffractive negative index lens with 150 mm focal length and 15 mm entrance pupil diameter is discussed from wavelength 0.848 ?m through wavelength 0.912 ?m to wavelength 1.114 ?m. According to the deduced expression for the NIM DOEs, the diffraction efficiency is calculated, and the diffraction efficiency curve is fitted by interpolation.

Piao, Mingxu; Cui, Qingfeng; Zhang, Bo

2015-02-01

22

Negative index metamaterial combining magnetic resonators with metal films  

Microsoft Academic Search

We present simulation results of a design for negative index materials that\\u000auses magnetic resonators to provide negative permeability and metal film for\\u000anegative permittivity. We also discuss the possibility of using semicontinuous\\u000ametal films to achieve better manufacturability and enhanced impedance\\u000amatching.

Uday K. Chettiar; Alexander V. Kildishev; Thomas A. Klar; Vladimir M. Shalaev

2006-01-01

23

Infrared magnetic and negative-index metamaterials  

NASA Astrophysics Data System (ADS)

Negative-index materials have attracted much attention because of their many unconventional optical properties such as negative refractive angle, phase back propagation, reversed Doppler effect and reversed Cherenkov radiation. Recently, much progress has been made in this research area such as demonstrations of negative permeability "metamaterials" in the rf and microwave regimes, and the predictions and demonstrations (largely in the rf) of negative index materials (and predictions of diffraction-less "perfect" imaging in these materials). In this dissertation, fabrication and characterization of several novel metal-based metamaterial that show unconventional IR/optical properties are discussed. While metals provide a negative permittivity at frequencies below the plasma frequency, naturally occurring materials with negative permeability at optical frequencies are not available. Composite electromagnetic materials with resonant structures with sizes much less than the wavelength can act as an effective homogeneous media with a negative permeability. One widely used structure to achieve negative permeability in rf is the so called "split ring resonator" (SRR) proposed by Pendry. By using SRR, the highest resonant frequency that has been obtained is around 1 THz. The complexity of SRR makes it difficult to be further scaled down to reach magnetic resonance at infrared frequencies, even with electron beam lithography. As part of this dissertation, the fabrication, characterization and modeling of arrays of a new nanostructure design with resonances in the mid-IR region and properties that demonstrate strong magnetic activity indicative of negative permeability are described. This is the first experimental work on negative permeability reported in the mid-IR. In addition, interferometric lithography (IL) combined with self-aligned semiconductor processing techniques were used for the fabrication, leading to large area samples with good uniformity. By combining structures with magnetic response and electrical response, a negative refractive index metamaterial is designed and fabricated using IL. The refractive index of the fabricated structure is obtained uniquely from the experimental results by measuring both the amplitude and phase of the transmission and reflectance. This is the first demonstration of negative index metamaterials in the near-IR, about 4 orders of magnitude shorter than previously reported work. Furthermore, parametric studies and experimental results show that better design with very low loss can be achieved, which might lead to more useful applications.

Zhang, Shuang

24

Cover Picture: Rapid Research Letter - Focusing slabs made of negative index materials based on inhomogeneous dielectric rods  

NASA Astrophysics Data System (ADS)

In the Rapid Research Letter [1] it is shown that a flat array of dielectric rods can act as a focusing lens of good quality - provided the rods have specified gradients of the dielectric constant. This design is superior to conventional photonic crystals (PC) utilizing homogeneous rods since the lens can be smaller and has better properties in a broader wavelength range.The cover picture is an artist's view of the PC lens made from dielectric rods consisting of three layers with the refractive index increasing from the margin to the center of the rod, focusing a light beam into a small spot. The focusing spot is controlled by the parameters of the rods and their arrangement in the PC slab.The first author, Dr. Vladimir Sergentu, is a senior researcher of the Laboratory of Low Dimensional Semiconductor Structures in Chisinau, Moldova, which works on the design of PC based optical elements in collaboration with the Universities of Kiel and Rochester.

Sergentu, V. V.; Ursaki, V. V.; Tiginyanu, I. M.; Foca, E.; Föll, H.; Boyd, Robert W.

2006-05-01

25

Measured Polarization Response of Negative Index Metamaterial  

Microsoft Academic Search

Free space microwave measurements are reported of a split ring and post type metamaterial that exhibits negative index of refraction in a frequency band near 13.5 GHz. Varying azimuthal angles and magnitudes are achieved by changing the polarization of the transmitter and receiver relative to each other and to the anisotropic material. The amplitude of the cross-polarized transmission has been

J. S. Derov; B. W. Turchinetz; E. E. Crisman; A. J. Drehman; S. R. Best

2005-01-01

26

Infrared magnetic and negative-index metamaterials  

Microsoft Academic Search

Negative-index materials have attracted much attention because of their many unconventional optical properties such as negative refractive angle, phase back propagation, reversed Doppler effect and reversed Cherenkov radiation. Recently, much progress has been made in this research area such as demonstrations of negative permeability \\

Shuang Zhang

2005-01-01

27

Connected bulk negative index photonic metamaterials  

E-print Network

"bulk" for a metamaterial with multiple unit cells in all three directions.) However, bulk isotropicConnected bulk negative index photonic metamaterials Durdu �. Güney,1, * Thomas Koschny,1,2 Maria); published February 12, 2009 We show the designs of bulk one- and two-dimensionally isotropic photonic

Soukoulis, Costas

28

Photorealistic rendering of a graded negative-index metamaterial magnifier  

NASA Astrophysics Data System (ADS)

A novel reverse design schematic for designing a metamaterial magnifier with graded negative refractive index for both the two-dimensional and three-dimensional cases has been proposed. Photorealistic rendering is integrated with trace ray trajectories in example designs to visualize the scattering magnification as well as imaging of the proposed graded-index magnifier with negative-index metamaterials. The material of the magnifying shell can be uniquely and independently determined without knowing beforehand the corresponding domain deformation. This reverse recipe and photorealistic rendering directly tackles the significance of all possible parametric profiles and demonstrates the performance of the device in a realistic scene, which provides a scheme to design, select and evaluate a metamaterial magnifier.

Qiu, Cheng-Wei; Akbarzadeh, Alireza; Han, Tiancheng; Danner, Aaron J.

2012-03-01

29

Structures with negative index of refraction  

DOEpatents

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.

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

2011-11-08

30

Evidence of Negative-Index Refraction in Nonlinear Chemical Waves  

NASA Astrophysics Data System (ADS)

The negative index of refraction of nonlinear chemical waves has become a recent focus in nonlinear dynamics researches. Theoretical analysis and computer simulations have predicted that the negative index of refraction can occur on the interface between antiwaves and normal waves in a reaction-diffusion (RD) system. However, no experimental evidence has been found so far. In this Letter, we report our experimental design in searching for such a phenomenon in a chlorite-iodide-malonic acid (CIMA) reaction. Our experimental results demonstrate that competition between waves and antiwaves at their interface determines the fate of the wave interaction. The negative index of refraction was only observed when the oscillation frequency of a normal wave is significantly smaller than that of the antiwave. All experimental results were supported by simulations using the Lengyel-Epstein RD model which describes the CIMA reaction-diffusion system.

Yuan, Xujin; Wang, Hongli; Ouyang, Qi

2011-05-01

31

Germanium-based negative-index heterostructure for high speed modulation  

NASA Astrophysics Data System (ADS)

We show that Ag/Ge/Ag 'fishnet'-like metal-semiconductor metamaterials can be designed to exhibit negative index material (NIM) behavior around 1.5 µm in spite of interband absorption in Ge becoming substantial in this region. We use the FDTD method with the Adachi model for an accurate account of the dielectric response in Ge. The system is expected to perform faster than Si-based fishnet, which is corroborated by preliminary data.

Bratkovsky, A. M.; Ponizovskaya, E. V.

2011-01-01

32

Bianisotropic negative-index metamaterial embedded in a symmetric medium  

E-print Network

, in previous reports the NIMs based on the fishnet struc- ture with negative refractive index at nearBianisotropic negative-index metamaterial embedded in a symmetric medium Zahyun Ku,1 Keshav M. Dani,2 Prashanth C. Upadhya,2 and S. R. J. Brueck1, * 1 Center for High Technology Materials

New Mexico, University of

33

Low-loss negative-index metamaterial at telecommunication wavelengths  

E-print Network

fabricate and characterize a low-loss silver-based negative-index metamaterial based on the design of the silver- based structure. Inset, magnified view. 1800 OPTICS LETTERS / Vol. 31, No. 12 / June 15, 2006, the structure can be thought of as consisting of double-plate (or double-wire) pairs5,6 as "magnetic atoms

Soukoulis, Costas

34

Radiation Pressure and Photon Momentum in Negative-Index Media  

E-print Network

Radiation pressure and photon momentum in negative-index media are no different than their counterparts in ordinary (positive-index) materials. This is because the parameters responsible for these properties are the admittance, sqrt(epsilon/mu), and the group refractive index n_g of the material (both positive entities), and not the phase refractive index, n=sqrt(epsilon*mu), which is negative in negative-index media. One approach to investigating the exchange of momentum between electromagnetic waves and material media is via the Doppler shift phenomenon. In this paper we use the Doppler shift to arrive at an expression for the radiation pressure on a mirror submerged in a negative-index medium. In preparation for the analysis, we investigate the phenomenon of Doppler shift in various settings, and show the conditions under which a so-called "inverse" Doppler shift could occur. We also argue that a recent observation of the inverse Doppler shift upon reflection from a negative-index medium cannot be correct,...

Mansuripur, Masud

2013-01-01

35

From Low-loss to Lossless Optical Negative-Index Materials U. K. Chettiar, A. V. Kildishev, T. A. Klar, H.-K. Yuan, W. Cai, A. K. Sarychev  

E-print Network

(metamaterials) in which the effective refractive index ( effn ) is negative. A truly negative index 0effn where the effective isotropic properties (permit- tivity i = + and permeability i = + ) obey active metamaterial arranged of two split ring resonantors (SRRs) of subwavelength dimensions

Shalaev, Vladimir M.

36

Low-loss negative-index metamaterial at telecommunication wavelengths  

Microsoft Academic Search

We fabricate and characterize a low-loss silver-based negative-index metamaterial based on the design of a recent theoretical proposal. Comparing the measured transmittance and reflectance spectra with theory reveals good agreement. We retrieve a real part of the refractive index of Re(n)=-2 around 1.5 mum wavelength. The maximum of the ratio of the real to the imaginary part of the refractive

Gunnar Dolling; Christian Enkrich; Martin Wegener; Costas M. Soukoulis; Stefan Linden

2006-01-01

37

Entanglement creation with negative index metamaterials  

E-print Network

We propose a scheme for creating of a maximally entangled state comprising two field quanta. In our scheme, two weak light fields, which are initially prepared in either coherent or polarization states, interact with a composite medium near an interface between a dielectric and a negative index metamaterial. Such interaction leads to a large Kerr nonlinearity, reduction of the group velocity of the light and significant confinement of the light fields while simultaneously avoiding amplitude losses of the incoming radiation. All these considerations make our scheme efficient.

Michael Siomau; Ali A. Kamli; Sergey A. Moiseev; Barry C. Sanders

2012-05-21

38

Magnetic plasmon-polaritons in negative index gyromagnetic media  

NASA Astrophysics Data System (ADS)

The focus of this report is the investigation of the influence of an external magnetic field on the peculiarities of coupled magnon-plasmon polaritons in two different types of negative index gyromagnetic media: conducting antiferromagnets and nonconducting antiferromagnet/nonmagnetic dielectric periodic structures. The necessary conditions are found for realization of the negative refraction in such materials. It is shown that the behavior of the waves in various ranges of the magnetic field is quite different, and both the number and limits of the frequency ranges, where the negative refraction can be realized, are very sensitive to the strength of the applied field.

Tarkhanyan, R. H.; Niarchos, D. G.

2010-07-01

39

Ultra low-loss, isotropic 2D optical negative-index metamaterial based on hybrid metal-semiconductor nanowires  

E-print Network

In the past few years, many of the fascinating and previously almost unconceivable properties predicted for those novel, artificial, man-made materials, so called metamaterials, were demonstrated to be not only a tangible reality, but a very useful one. However, plenty of the best achievements in that newly discovered field are far from having a direct translation to the, in many aspects more interesting, high frequency range, without being burdened not only by technological difficulties, but also conceptual ones. Of particular importance within the realm of optical metamaterials having a negative index of refraction, often designated negative-index metamaterials (NIM), is the issue of simultaneously achieving a strong response of the system and low associated losses. In the present work, we demonstrate the possibility to use hybrid metal-semiconductor nanowires to obtain an isotropic optical NIM, with very strong electric and magnetic responses, which exhibits extremely low losses (about two orders of magnit...

Paniagua-Dominguez, R; Sanchez-Gil, J A

2012-01-01

40

Low-loss multilayered metamaterial exhibiting a negative index of refraction at visible wavelengths  

NASA Astrophysics Data System (ADS)

Over the last decade, metamaterials have attracted a great interest thanks to their potential to expand the range of electromagnetic properties found in natural materials. In particular, the possibility of achieving negative refractive index media (NIM) enables us to implement superlenses and optical storing devices. Since the first experimental demonstration at microwave frequencies, much effort has been put in extending negative refraction to the visible spectrum, where we can take full advantage of NIM properties. For instance, the superior imaging ability of NIM would be essential for visible microscopy. The desired features for NIM are low loss and isotropy. This last property includes polarization independence and negative-index behavior in all spatial directions. None of these features have been attained in previous experiments. Thus, the current challenge is to improve such aspects in order to make NIM suitable for practical applications. In this work, we experimentally demonstrate a low-loss multilayer metamaterial exhibiting a double-negative index in the visible spectrum, while presenting polarization independence at normal incidence. This has been achieved by exploiting the properties of a second-order magnetic resonance of the so-called fishnet structure, in contrast to previous works that used first-order magnetic resonances, both related to gap surface plasmon polariton (SPP) modes. The low-loss nature of the employed magnetic resonance, together with the effect of the interacting adjacent layers, results in a figure of merit as high as 3.34. A wide spectral range of negative index is achieved, covering the wavelength region between 620 and 806 nm with only two different designs. The fabricated metamaterials are the first experimental multilayer NIM in the visible spectrum, which entails an important step towards homogeneous NIM in this range. Finally, we found that the SPP modes determining the permeability resonance display weak angular dispersion.

Garcia-Meca, Carlos

2012-02-01

41

High symmetry versus optical isotropy of a negative index metamaterial  

E-print Network

Optically isotropic metamaterials (MMs) are required for the implementation of subwavelength imaging systems. At first glance one would expect that their design should be based on unit cells exhibiting a cubic symmetry being the highest crystal symmetry. It is anticipated that this is a sufficient condition since it is usually assumed that light does not resolve the spatial details of MM but experiences the properties of an effective medium, which is then optically isotropic. In this work we challenge this assumption by analyzing the isofrequency surfaces of the dispersion relation of the split-cube in carcass (SCiC) negative index MM. We show that this MM is basically optically isotropic, but not in the spectral domain where it exhibits negative refraction. The primary goal of this contribution is to introduce a tool that allows to probe a MM against optical isotropy.

Menzel, Christoph; Rockstuhl, Carsten; Iliew, Rumen; Malureanu, Radu; Lederer, Falk; Lavrinenko, Andrei V

2010-01-01

42

Negative Index Photonic Crystals Superlattices and Zero Phase Delay Lines  

E-print Network

sources or antennas, #12;Negative Index Photonic Crystals Superlattices and Zero Phase Delay Lines 32916 Negative Index Photonic Crystals Superlattices and Zero Phase Delay Lines C. W. Wong et al optical losses in their metallic components. As an alternative, dielectric based photonic crystals (Ph

Hone, James

43

Sub-picosecond optical switching with a negative index metamaterial  

SciTech Connect

Development of all-optical signal processing, eliminating the performance and cost penalties of optical-electrical-optical conversion, is important for continu,ing advances in Terabits/sec (Tb/s) communications.' Optical nonlinearities are generally weak, traditionally requiring long-path, large-area devicesl,2 or very high-Q, narrow-band resonator structures.3 Optical metamaterials offer unique capabilities for optical-optical interactions. Here we report 600 femtosecond (fs) all-optical modulation using a fIShnet (2D-perforated metallamorphous-Si (a-Si)/metal film stack) negative-index meta material with a structurally tunable broad-band response near 1.2 {micro}m. Over 20% modulation (experimentally limited) is achieved in a path length of only 116 nm by photo-excitation of carriers in the a-Si layer. This has the potential for Tb/s aU-optical communication and will lead to other novel, compact, tunable sub-picosecond (ps) photonic devices.

Dani, Keshav M [Los Alamos National Laboratory; Upadhya, Prashant C [Los Alamos National Laboratory; Zahyum, Ku [CHTM-UNM

2009-01-01

44

Subpicosecond Optical Switching with a Negative Index Metamaterial  

E-print Network

Subpicosecond Optical Switching with a Negative Index Metamaterial Keshav M. Dani,*, Zahyun Ku Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, and Center for High Technology in the near-IR. The 600 fs response, 2 orders of magnitude faster than previously reported, is achieved

New Mexico, University of

45

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

Microsoft Academic Search

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.

Durdu Ö. Güney; Thomas Koschny; Costas M. Soukoulis

2010-01-01

46

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

E-print Network

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.

Guney, Durdu O; Soukoulis, Costas M

2010-01-01

47

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

PubMed

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. PMID:20588360

Güney, Durdu O; Koschny, Thomas; Soukoulis, Costas M

2010-06-01

48

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

SciTech Connect

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.

Guney, Durdu; Koschny, Thomas; Soukoulis, Costas

2010-05-26

49

Negative index metamaterials based on metal-dielectric nanocomposites for imaging applications  

E-print Network

Negative index metamaterials based on metal-dielectric nanocomposites for imaging applications L; published online 25 September 2008 Negative index metamaterials are demonstrated based on metal such a negative index metamaterial, we have used a versatile bottom-up nanofabrication approach to prepare a high

Sridhar, Srinivas

50

Resonant nonlinear optics of backward waves in negative-index metamaterials  

E-print Network

The extraordinary properties of resonant four-wave mixing of backward waves in doped negative-index materials are investigated. The feasibility of independent engineering of negative refractive index and nonlinear optical response as well as quantum control of the nonlinear propagation process in such composites is shown due to the coherent energy transfer from the control to the signal field. Laser-induced transparency, quantum switching, frequency-tunable narrow-band filtering, amplification, and realizing a miniature mirrorless optical parametric generator of the entangled backward and ordinary waves are among the possible applications of the investigated processes.

Alexander K. Popov; Sergei A. Myslivets; Vladimir M. Shalaev

2008-08-14

51

Three-dimensional negative index of refraction at optical frequencies by coupling plasmonic waveguides  

E-print Network

We identify a route towards achieving a negative index of refraction at optical frequencies based on coupling between plasmonic waveguides that support backwards waves. We show how modal symmetry can be exploited in metal-dielectric waveguide pairs to achieve negative refraction of both phase and energy. By properly controlling coupling between adjacent waveguides, a metamaterial consisting of a one-dimensional multilayer stack exhibiting an isotropic index of -1 can be achieved at a free-space wavelength of 400 nm. The general concepts developed here may inspire new low-loss metamaterial designs operating close to the metal plasma frequency.

Verhagen, Ewold; L.,; Kuipers,; Polman, Albert

2010-01-01

52

Three-Dimensional Negative Index of Refraction at Optical Frequencies by Coupling Plasmonic Waveguides  

NASA Astrophysics Data System (ADS)

We identify a route towards achieving a negative index of refraction at optical frequencies based on coupling between plasmonic waveguides that support backwards waves. We show how modal symmetry can be exploited in metal-dielectric waveguide pairs to achieve negative refraction of both phase and energy. Control of waveguide coupling yields a metamaterial consisting of a one-dimensional multilayer stack that exhibits an isotropic index of -1 at a free-space wavelength of 400 nm. The concepts developed here may inspire new low-loss metamaterial designs operating close to the metal plasma frequency.

Verhagen, Ewold; de Waele, René; Kuipers, L.; Polman, Albert

2010-11-01

53

Three-dimensional negative index of refraction at optical frequencies by coupling plasmonic waveguides.  

PubMed

We identify a route towards achieving a negative index of refraction at optical frequencies based on coupling between plasmonic waveguides that support backwards waves. We show how modal symmetry can be exploited in metal-dielectric waveguide pairs to achieve negative refraction of both phase and energy. Control of waveguide coupling yields a metamaterial consisting of a one-dimensional multilayer stack that exhibits an isotropic index of -1 at a free-space wavelength of 400 nm. The concepts developed here may inspire new low-loss metamaterial designs operating close to the metal plasma frequency. PMID:21231386

Verhagen, Ewold; de Waele, René; Kuipers, L; Polman, Albert

2010-11-26

54

Materials and design interface  

NASA Astrophysics Data System (ADS)

The unprecedented demands faced by fusion structures primarily derive from severe time varying thermal-mechanical loading of complex, large scale, and highly interconnected heat transfer-energy conversion structures. This grand challenge is often much too narrowly couched in terms of the development of radiation damage resistant materials, while the enormously larger challenge is the creation of material systems and multifunctional structures. In addition, the fusion system designer is faced with the untenable situation that neither the fully functional materials, nor the requisite computational tools, nor experimental simulation facilities currently exist for reliable integrity and lifetime assessments of fusion reactor structures. Considering the absence of material information and design tools, neither the materials nor the fusion designer can follow standard design processes. The design process has to become actively materials-related while materials development must closely follow design process needs. This indispensible interaction between materials and design processes leads to a 'concurrent materials-structure design' path, which is necessary to meet the enormous materials-structural engineering challenges of fusion.

Sharafat, S.; Odette, G. R.; Blanchard, J.

2009-04-01

55

Designing Printed Instructional Materials.  

ERIC Educational Resources Information Center

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)

Burbank, Lucille; Pett, Dennis

1986-01-01

56

Metallo-dielectric core-shell nanospheres as building blocks for optical three-dimensional isotropic negative-index metamaterials  

NASA Astrophysics Data System (ADS)

Materials showing electromagnetic properties that are not attainable in naturally occurring media, so-called metamaterials, have been lately, and still are, among the most active topics in optical and materials physics and engineering. Among these properties, one of the most attractive ones is the sub-diffraction resolving capability predicted for media having an index of refraction of -1. Here, we propose a fully three-dimensional, isotropic metamaterial with strong electric and magnetic responses in the optical regime, based on spherical metallo-dielectric core-shell nanospheres. The magnetic response stems from the lowest, magnetic-dipole resonance of the dielectric shell with a high refractive index, and can be tuned to coincide with the plasmon resonance of the metal core, responsible for the electric response. Since the response does not originate from coupling between structures, no particular periodic arrangement needs to be imposed. Moreover, due to the geometry of the constituents, the metamaterial is intrinsically isotropic and polarization independent. It could be realized with current fabrication techniques with materials such as silver (core) and silicon or germanium (shell). For these particular realistic designs, the metamaterials present a negative index in the range of 1.2-1.55 ?m.

Paniagua-Domínguez, R.; López-Tejeira, F.; Marqués, R.; Sánchez-Gil, J. A.

2011-12-01

57

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

E-print Network

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 simultaenously 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.

F. Bello

2011-07-01

58

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

SciTech Connect

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.

Bello, F. [Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain)

2011-07-15

59

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

E-print Network

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 simultaenously 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.

Bello, F

2011-01-01

60

Focusing on the graded negative index flat by annular photonic crystal  

NASA Astrophysics Data System (ADS)

Focusing on the graded negative index lens made by annular photonic crystals (APCs) are theoretically studied. The graded annular photonic crystal (GAPC) is composed of a dielectric-rod and a circular-air-hole array in a triangular lattice. The grade index is achieved by gradual modification of the radius of the rod along the transverse direction to propagation. The properties of the GAPC are analyzed by using the Plane Wave Expansion (PWE) method and numerical simulation is studied by using the Finite-Difference Time-Domain (FDTD) method. The results show that the GAPC can realize the focus of plane waves and the focal length can be designed with the wave frequency.

Xia, Feng; Wang, Mei; Liu, Meiling; Lv, Wei; Zhang, Zan; Yun, Maojin

2013-09-01

61

Tunable split-ring resonators for nonlinear negative-index metamaterials  

E-print Network

Tunable split-ring resonators for nonlinear negative-index metamaterials Ilya V. Shadrivov, Steven; (999.9999) Metamaterials. References and links 1. C. Soukoulis, "Bending back light: The science. Drachev, and A. V. Kildishev, "Negative index of refraction in optical metamaterials," Opt. Lett. 30, 3356

62

Ultra low-loss, isotropic optical negative-index metamaterial based on hybrid metal-semiconductor nanowires  

PubMed Central

Recently, many fascinating properties predicted for metamaterials (negative refraction, superlensing, electromagnetic cloaking,…) were experimentally demonstrated. Unfortunately, the best achievements have no direct translation to the optical domain, without being burdened by technological and conceptual difficulties. Of particular importance within the realm of optical negative-index metamaterials (NIM), is the issue of simultaneously achieving strong electric and magnetic responses and low associated losses. Here, hybrid metal-semiconductor nanowires are proposed as building blocks of optical NIMs. The metamaterial thus obtained, highly isotropic in the plane normal to the nanowires, presents a negative index of refraction in the near-infrared, with values of the real part well below ?1, and extremely low losses (an order of magnitude better than present optical NIMs). Tunability of the system allows to select the operating range in the whole telecom spectrum. The design is proven in configurations such as prisms and slabs, directly observing negative refraction. PMID:23514968

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

2013-01-01

63

Ultra low-loss, isotropic optical negative-index metamaterial based on hybrid metal-semiconductor nanowires.  

PubMed

Recently, many fascinating properties predicted for metamaterials (negative refraction, superlensing, electromagnetic cloaking,…) were experimentally demonstrated. Unfortunately, the best achievements have no direct translation to the optical domain, without being burdened by technological and conceptual difficulties. Of particular importance within the realm of optical negative-index metamaterials (NIM), is the issue of simultaneously achieving strong electric and magnetic responses and low associated losses. Here, hybrid metal-semiconductor nanowires are proposed as building blocks of optical NIMs. The metamaterial thus obtained, highly isotropic in the plane normal to the nanowires, presents a negative index of refraction in the near-infrared, with values of the real part well below -1, and extremely low losses (an order of magnitude better than present optical NIMs). Tunability of the system allows to select the operating range in the whole telecom spectrum. The design is proven in configurations such as prisms and slabs, directly observing negative refraction. PMID:23514968

Paniagua-Domínguez, R; Abujetas, D R; Sánchez-Gil, J A

2013-01-01

64

Design a Sculpting Material  

ERIC Educational Resources Information Center

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…

Roman, Harry T.

2011-01-01

65

Design of a novel negative refractive index material based on numerical simulation  

NASA Astrophysics Data System (ADS)

This paper presents a novel metamaterial constructed with wires, spheres and hollow slabs (WSHS), which simultaneously exhibits negative permittivity and permeability. An electromagnetic wave simulation is performed based on the proposed metamaterial and shows that a negative refractive index is achieved for this metamaterial. Adjusting the lattice constant of the unit cell is an easy way to manipulate the frequency of negative index of this structure. A left-hand material prism is designed composed of metamaterial unit cells and the simulation on the proposed prism proves the left-hand behavior of the designed metamaterial.

Rizwan, Muhammad; Dou, Yan-Kun; Jin, Hai-Bo; Hou, Zhi-Ling; Kong, Ling-Bao; Li, Jing-Bo; Butt, Faheem K.; Rehman, Fida

2013-07-01

66

Designer quantum materials  

NASA Astrophysics Data System (ADS)

Spin-based quantum information processing relies on the ability to identify and coherently manipulate quantum bits (qubits) existing in nature in the form of spin-½ particles such as electrons. The work described in this thesis is based on an alternative perspective: that these spin-½ objects, together with their interactions, can be regarded as building blocks of a variety of "designer quantum materials" with features not present for isolated single spins. Theoretical proposals are presented for two classes of spin-based designer quantum materials relevant for quantum information transport and manipulation. The first class of materials involves spin-½ networks coupled by spatially-varying exchange interactions, in which moving domain walls can produce topologically-stable "flying spin qubits," and pairs of domain walls can be used to generate and transport Einstein-Podolsky-Rosen pairs of entangled qubits. The effective exchange between two domain-wall qubits can be tuned by adjusting the positions of the domain walls and can be ferromagnetic even when all spin-spin couplings are antiferromagnetic. The second class of designer quantum materials consists of electron spins in quantum wires with spatially-varying spin-orbit coupling. The presence of the spin-orbit interaction introduces pseudo-Zeeman couplings of the electron spins to effective magnetic fields and further enhances the building-block toolset: by periodically modulating this spin-orbit coupling in space, it is possible to create the spatial analogue of spin resonance, without the need for any real magnetic fields. The mapping of time-dependent operations onto a spatial axis suggests a new mode for quantum information processing in which gate operations are encoded into the band structure of the material.

Srinivasa, Vanita

67

Experimental Verification of a Negative Index of Refraction  

Microsoft Academic Search

We present experimental scattering data at microwave frequencies on a structured metamaterial that exhibits a frequency band where the effective index of refraction (n) is negative. The material consists of a two-dimensional array of repeated unit cells of copper strips and split ring resonators on interlocking strips of standard circuit board material. By measuring the scattering angle of the transmitted

R. A. Shelby; D. R. Smith; S. Schultz

2001-01-01

68

Demonstration of metal-dielectric negative-index metamaterials with improved performance at optical frequencies  

Microsoft Academic Search

We experimentally demonstrate a comparatively low-loss negative-index metamaterial with the magnitude of the real part of the index comparable with the imaginary part. Over 40% transmission is achieved in the negative-index region by structural adjustment of the impedance matching between the metamaterial and the air-substrate claddings. This structure has the potential of achieving high transmission and small loss in the

Shuang Zhang; Wenjun Fan; Kevin J. Malloy; Steven R. J. Brueck; Nicolae C. Panoiu; Richard M. Osgood

2006-01-01

69

Soft 3D acoustic metamaterial with negative index  

NASA Astrophysics Data System (ADS)

Many efforts have been devoted to the design and achievement of negative-refractive-index metamaterials since the 2000s. One of the challenges at present is to extend that field beyond electromagnetism by realizing three-dimensional (3D) media with negative acoustic indices. We report a new class of locally resonant ultrasonic metafluids consisting of a concentrated suspension of macroporous microbeads engineered using soft-matter techniques. The propagation of Gaussian pulses within these random distributions of ‘ultra-slow’ Mie resonators is investigated through in situ ultrasonic experiments. The real part of the acoustic index is shown to be negative (up to almost ? 1) over broad frequency bandwidths, depending on the volume fraction of the microbeads as predicted by multiple-scattering calculations. These soft 3D acoustic metamaterials open the way for key applications such as sub-wavelength imaging and transformation acoustics, which require the production of acoustic devices with negative or zero-valued indices.

Brunet, Thomas; Merlin, Aurore; Mascaro, Benoit; Zimny, Kevin; Leng, Jacques; Poncelet, Olivier; Aristégui, Christophe; Mondain-Monval, Olivier

2015-04-01

70

Soft 3D acoustic metamaterial with negative index.  

PubMed

Many efforts have been devoted to the design and achievement of negative-refractive-index metamaterials since the 2000s. One of the challenges at present is to extend that field beyond electromagnetism by realizing three-dimensional (3D) media with negative acoustic indices. We report a new class of locally resonant ultrasonic metafluids consisting of a concentrated suspension of macroporous microbeads engineered using soft-matter techniques. The propagation of Gaussian pulses within these random distributions of 'ultra-slow' Mie resonators is investigated through in situ ultrasonic experiments. The real part of the acoustic index is shown to be negative (up to almost - 1) over broad frequency bandwidths, depending on the volume fraction of the microbeads as predicted by multiple-scattering calculations. These soft 3D acoustic metamaterials open the way for key applications such as sub-wavelength imaging and transformation acoustics, which require the production of acoustic devices with negative or zero-valued indices. PMID:25502100

Brunet, Thomas; Merlin, Aurore; Mascaro, Benoit; Zimny, Kevin; Leng, Jacques; Poncelet, Olivier; Aristégui, Christophe; Mondain-Monval, Olivier

2015-04-01

71

Negative index fishnet structures with nanopillars formed by nanoimprint lithography  

NASA Astrophysics Data System (ADS)

Since their inception, metamaterial fishnet structures have frequently been used to exhibit a negative refractive index. Their shape and structure make it possible to independently produce both a negative permeability (?) and a negative permittivity (?). Fishnets that display this characteristic can be referred to as a double negative metamaterial. Although other techniques have been demonstrated, fishnets are commonly fabricated using electron-beam lithography (EBL) or focused ion-beam (FIB) milling. In this paper we demonstrate the fabrication of fishnets using nano-imprint lithography (NIL). Advantages associated with NIL include a shorter fabrication time, a larger feasible pattern area and reduced costs. In addition to these advantages, the quality of the fabricated structures is excellent. We imprint a stamp directly into a metal-dielectric-metal stack which creates the fishnet and, as an artifact of the technique, a periodic array of nanopillars. Two different designs of the fishnet and nanopillar structure have been fabricated and optical measurements have been taken from both. In addition to the experimental measurements the structures have also been extensively simulated, suggesting a negative refractive index with a real part as large in magnitude as five can be achieved.

Sharp, Graham J.; Khan, Saima I.; Khokhar, Ali Z.; De La Rue, Richard M.; Johnson, Nigel P.

2014-05-01

72

Broadband 3D isotropic negative-index metamaterial based on fishnet structure  

NASA Astrophysics Data System (ADS)

In this paper, we numerically demonstrate a broadband 3D isotropic negative index metamaterial (NIM) at microwave frequency ranges, which is composed of double periodic array metallic fishnet structure (FS) etched on the six sides of a cubic dielectric substrate. The electric and magnetic L- C resonance circuit models are constructed to demonstrate the broadband resonance properties of the proposed 3D metamaterial. The finite integration technology (FIT) simulation and standard S parameters retrieval methods are used to calculate and analyze the negative characteristics, isotropy and polarization of the 3D model. The numerical results show that the negative index bandwidth is about 7 GHz and relative bandwidth can be up nearly to 63%, the negative-index pass band is independent of the polarization of incident waves and is almost the same for different oblique incident angles. Thus, the proposed metamaterial is good candidate as a broad-band 3D isotropic NIMs.

Cheng, Y. Z.; Nie, Y.; Gong, R. Z.

2012-02-01

73

Measurements of Broadband Negative Index in Space-Coiling Acoustic Metamaterials  

E-print Network

We report the experimental demonstration of broadband negative refractive index obtained in a labyrinthine acoustic metamaterial structure. Two different approaches were employed to prove the metamaterial negative index nature: one-dimensional extractions of effective parameters from reflection and transmission measurements, and two-dimensional prism-based measurements that convincingly show the transmission angle corresponding to negative refraction. The transmission angles observed in the latter case also agree very well with the refractive index obtained in the one-dimensional measurements and numerical simulations. We expect this labyrinthine metamaterial to become the unit cell of choice for practical acoustic metamaterial devices that require broadband and significantly negative indexes of refraction.

Xie, Yangbo; Zigoneanu, Lucian; Cummer, Steven A

2012-01-01

74

Material-based design computation  

E-print Network

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 ...

Oxman, Neri

2010-01-01

75

Materials in design  

E-print Network

is usually the least expensive one. In the cost we should consider not only the cost of materials and production but also engineering costs. Engineering analysis leads us to a relation between overall cost for dif- ferent materials and a geometrical... structural materials and its very light weight magnesium alloys has become a strong contender in the highly competitive field of structural alloys. It has 2/3 the weight of aluminum and I/4 the weight of steel. Some of the alloys respond to age hardening...

Perata, Alfredo Ferando

1970-01-01

76

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

E-print Network

transmission through a two- dimensional, isotropic left-handed metamaterial," Appl. Phys. Lett. 78, 489 (2001Negative index short-slab pair and continuous wires metamaterials in the far infrared regime T. F incidence in one and three layers of a m-scale metamaterial consisting of pairs of short

Soukoulis, Costas

77

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

E-print Network

Intra-connected three-dimensionally isotropic bulk negative index photonic metamaterial Durdu Ã? of three-dimensionally (3D) isotropic bulk optical metamaterials, but only at the expense of an additional of isotropic bulk magnetic metamaterials using the cubic point groups of symmetry," Phys. Rev. B 76(24), 245115

78

The Goos-Hänchen effect at the non periodic surface of a negative index metamaterial  

Microsoft Academic Search

We investigate the lateral displacement (Goos-Hänchen lateral shift) of a linearly polarized Gaussian beam reflected from a corrugated surface between a conventional dielectric and a homogeneous isotropic metamaterial with a negative index of refraction. We pay particular attention to effects associated with the resonant excitation of surface plasmon polaritons. The dependence of the lateral displacement on the incident beam parameters

Vivian Grünhut; Mauro Cuevas; Ricardo A. Depine

2011-01-01

79

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

E-print Network

transmission through a two- dimensional, isotropic left-handed metamaterial," Appl. Phys. Lett. 78, 489 (2001Negative index short-slab pair and continuous wires metamaterials in the far infrared regime T. F-scale metamaterial consisting of pairs of short- slabs and continuous wires, fabricated by a photolithography

80

Strongly birefringent metamaterials as negative index terahertz wave plates P. Weis,1,2,a  

E-print Network

plates with high transmission in the terahertz regime. The wave plates are based on strongly birefringentStrongly birefringent metamaterials as negative index terahertz wave plates P. Weis,1,2,a O. Paul,1 reported at terahertz frequencies. © 2009 American Institute of Physics. doi:10.1063/1.3253414 In the past

81

Ultrafast nonlinear optical spectroscopy of a dual-band negative index metamaterial  

E-print Network

. Padilla, J. M. O. Zide, A. C. Gossard, A. J. Taylor, and R. D. Averitt, "Active terahertz metamaterial, and R. D. Averitt, "Reconfigurable terahertz metamaterials," Phys. Rev. Lett. 103(14), 147401 (2009). 9. M. Bratkovsky, S. Wang, and R. S. Williams, "Modulation of negative index metamaterials in the near

New Mexico, University of

82

Four-wave mixing, quantum control and compensating losses in doped negative-index photonic metamaterials  

E-print Network

The possibility of compensating absorption in negative-index metatamterials (NIMs) doped by resonant nonlinear-optical centers is shown. The role of quantum interference and extraordinary properties of four-wave parametric amplification of counter-propagating electromagnetic waves in NIMs are discussed.

Alexander K. Popov; Sergey A. Myslivets; Thomas F. George; Vladimir M. Shalaev

2007-08-13

83

Influence of Filling Medium of Holes on the Negative-Index Response of Sandwiched Metamaterials  

Microsoft Academic Search

We numerically study the negative index properties of sandwiched metamaterials, perforated with a square array of circle holes filled with different media. Transmission spectra indicate that the filling medium can effectively change the position of the localized resonant peak, while keeping the position of the other transmission peaks hardly changed. Reflection spectra and retrieved effective impedance verify that an appropriate

Xu-Dong Wang; Yong-Hong Ye; Ji Ma; Mei-Ping Jiang

2010-01-01

84

SHORT PROGRAMS Materials By Design  

E-print Network

techniques including 3D printing, self-assembly, microfluidics and other technologies. We will distribute and analyze material samples designed based on multiscale simulations and manufactured using 3D printing

Entekhabi, Dara

85

Low loss broadband polarization independent fishnet negative index metamaterial at 40 GHz  

NASA Astrophysics Data System (ADS)

We present a polarization independent fishnet negative index metamaterial at 40 GHz. The structure is investigated theoretically using finite element method simulations and experimentally by measuring the amplitude and phase of the S-parameters. The experimental setup for free space measurements of both transmission and reflection is hereby introduced. The internal properties are thereafter retrieved and show the double-negative behavior of the structure. This negative index metamaterial exhibits very high transmission (-0.13 dB), low reflection (-33.1 dB) and a high figure of merit (FOM = |Re(n)/Im(n)| = 42), where the real part of the refractive index is nearly -1 (Re(n) = -0.93) at 40 GHz.

Zaoui, Wissem Sfar; Chen, Ke; Vogel, Wolfgang; Berroth, Manfred

2012-06-01

86

Anomalous Negative Group Velocity in Coupled Positive-Index\\/Negative-Index Guides Supporting Complex Modes  

Microsoft Academic Search

Anomalous negative group velocity (NGV; group ve- locity antiparallel to the power flow) is reported in a guided-wave structure supporting complex modes. This structure consists of a coupled-line system comprising a positive-index microstrip line edge coupled to a negative-index line. The NGV can be observed on the positive-index line under suitable excitation and termina- tion conditions. What is remarkable about

Hassan Mirzaei; Rubaiyat Islam; George V. Eleftheriades

2011-01-01

87

A Novel Two-Dimensional Negative Index Metamaterial Suitable for Planar Processing  

Microsoft Academic Search

A new negative index metamaterial based on a two-dimensional periodic array of capacitively-loaded metallic scatterers will be described. This structure is used to create a negative effective index of refraction for one polarization of wave incident from free space. The band structure was calculated using the Finite-Difference Time-Domain method, along with the Matrix Pencil Method. A band with backward-wave behaviour

Mark S. Wheeler; J. Stewart Aitchison; Mohammad Mojahedi

2004-01-01

88

Low loss broadband polarization independent fishnet negative index metamaterial at 40 GHz  

Microsoft Academic Search

We present a polarization independent fishnet negative index metamaterial at 40GHz. The structure is investigated theoretically using finite element method simulations and experimentally by measuring the amplitude and phase of the S-parameters. The experimental setup for free space measurements of both transmission and reflection is hereby introduced. The internal properties are thereafter retrieved and show the double-negative behavior of the

Wissem Sfar Zaoui; Ke Chen; Wolfgang Vogel; Manfred Berroth

89

Material feedback in digital design tools  

E-print Network

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 ...

Stanton, Christian J

2009-01-01

90

The Goos-Hänchen effect at the non periodic surface of a negative index metamaterial  

NASA Astrophysics Data System (ADS)

We investigate the lateral displacement (Goos-Hänchen lateral shift) of a linearly polarized Gaussian beam reflected from a corrugated surface between a conventional dielectric and a homogeneous isotropic metamaterial with a negative index of refraction. We pay particular attention to effects associated with the resonant excitation of surface plasmon polaritons. The dependence of the lateral displacement on the incident beam parameters is examined in detail and discussed in different situations among which is the total reflection case. We compare these characteristics with the limiting case of reflection of a beam from a surface with infinitely periodic corrugations.

Grünhut, Vivian; Cuevas, Mauro; Depine, Ricardo A.

2011-10-01

91

Negative-Index Metamaterials: Second-Harmonic Generation, Manley-Rowe Relations and Parametric Amplification  

E-print Network

Second harmonic generation and optical parametric amplification in negative-index metamaterials (NIMs) are studied. The opposite directions of the wave vector and the Poynting vector in NIMs results in a "backward" phase-matching condition, causing significant changes in the Manley-Rowe relations and spatial distributions of the coupled field intensities. It is shown that absorption in NIMs can be compensated by backward optical parametric amplification. The possibility of distributed-feedback parametric oscillation with no cavity has been demonstrated. The feasibility of the generation of entangled pairs of left- and right-handed counter-propagating photons is discussed.

A. K. Popov; Vladimir M. Shalaev

2006-01-10

92

Measurement of a Broadband Negative Index with Space-Coiling Acoustic Metamaterials  

NASA Astrophysics Data System (ADS)

We report the experimental demonstration of a broadband negative refractive index obtained in a labyrinthine acoustic metamaterial structure. Two different approaches were employed to prove the metamaterial negative index nature: one-dimensional extractions of effective parameters from reflection and transmission measurements and two-dimensional prism-based measurements that convincingly show the transmission angle corresponding to negative refraction. The transmission angles observed in the latter case also agree very well with the refractive index obtained in the one-dimensional measurements and numerical simulations. We expect this labyrinthine metamaterial to become the unit cell of choice for practical acoustic metamaterial devices that require broadband and significantly negative indices of refraction.

Xie, Yangbo; Popa, Bogdan-Ioan; Zigoneanu, Lucian; Cummer, Steven A.

2013-04-01

93

Principles of Inorganic Materials Design  

NASA Astrophysics Data System (ADS)

A unique interdisciplinary approach to inorganic materials design Textbooks intended for the training of chemists in the inorganic materials field often omit many relevant topics. With its interdisciplinary approach, this book fills that gap by presenting concepts from chemistry, physics, materials science, metallurgy, and ceramics in a unified treatment targeted towards the chemistry audience. Semiconductors, metal alloys and intermetallics, as well as ceramic substances are covered. Accordingly, the book should also be useful to students and working professionals in a variety of other disciplines. This book discusses a number of topics that are pertinent to the design of new inorganic materials but are typically not covered in standard solid-state chemistry books. The authors start with an introduction to structure at the mesoscopic level and progress to smaller-length scales. Next, detailed consideration is given to both phenomenological and atomistic-level descriptions of transport properties, the metal-nonmetal transition, magnetic and dielectric properties, optical properties, and mechanical properties. Finally, the authors present introductions to phase equilibria, synthesis, and nanomaterials. Other features include: Worked examples demonstrating concepts unfamiliar to the chemist Extensive references to related literature, leading readers to more in-depth coverage of particular topics Biographies introducing the reader to great contributors to the field of inorganic materials science in the twentieth century With their interdisciplinary approach, the authors have set the groundwork for communication and understanding among professionals in varied disciplines who are involved with inorganic materials engineering. Armed with this publication, students and researchers in inorganic and physical chemistry, physics, materials science, and engineering will be better equipped to face today's complex design challenges. This textbook is appropriate for senior-level undergraduate and graduate course work.

Lalena, John N.; Cleary, David

2005-04-01

94

Material parameter retrieval procedure for general bi-isotropic metamaterials  

E-print Network

Material parameter retrieval procedure for general bi-isotropic metamaterials and its application through the metamaterial. An effective material parameter retrieval procedure is developed for general bi-isotropic to optical chiral negative-index metamaterial design Do-Hoon Kwon,1 Douglas H. Werner,1, Alexander V

Shalaev, Vladimir M.

95

Measurement of a broadband negative index with space-coiling acoustic metamaterials.  

PubMed

We report the experimental demonstration of a broadband negative refractive index obtained in a labyrinthine acoustic metamaterial structure. Two different approaches were employed to prove the metamaterial negative index nature: one-dimensional extractions of effective parameters from reflection and transmission measurements and two-dimensional prism-based measurements that convincingly show the transmission angle corresponding to negative refraction. The transmission angles observed in the latter case also agree very well with the refractive index obtained in the one-dimensional measurements and numerical simulations. We expect this labyrinthine metamaterial to become the unit cell of choice for practical acoustic metamaterial devices that require broadband and significantly negative indices of refraction. PMID:23679743

Xie, Yangbo; Popa, Bogdan-Ioan; Zigoneanu, Lucian; Cummer, Steven A

2013-04-26

96

Designing polarization insensitive negative index metamaterial for operation in near infrared  

NASA Astrophysics Data System (ADS)

Hexagonal arrays of gold nanoelements with C3 symmetry are studied as a metamaterial slab of reduced anisotropy. Tri-dimensional (3D) finite-difference time domain (FDTD) simulations are used to calculate the reflected and transmitted electromagnetic field for two waves normally incident to the slab with mutually perpendicular polarizations. S-parameter method is used to retrieve the constitutive parameters for each polarization. While dipolar plasmonic resonance in the case of one layer metamaterial slab leads only to negative values of permittivity, using two layers of asymmetric nanoelements leads to a negative refractive index metamaterial in the near infrared range (158-172 THz) as a result of hybridized plasmonic states inversion.

Giloan, M.; Astilean, S.

2012-04-01

97

Material and processes selection in conceptual design  

E-print Network

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...

Krishnakumar, Karthikeyan

2005-02-17

98

A copper negative index metamaterial in the visible/near-infrared J. Parsonsa)  

E-print Network

. Our proposed design has a figure of merit comparable to similar silver-based metamaterials operating response. These geometries include split-ring resonators, cut- wire pairs, and meshed structures silver (Ag) or gold (Au) since these materials possess both large ­Re(e) and have losses which

Polman, Albert

99

Surface polaritons in a negative-index metamaterial with active Raman gain  

NASA Astrophysics Data System (ADS)

We propose a scheme to realize stable propagation of linear and nonlinear surface polaritons (SPs) by placing a N -type four-level quantum emitters at the interface between a dielectric and a negative-index metamaterial (NIMM). We show that in linear propagation regime SPs can acquire an active Raman gain (ARG) from a pump field and a gain doublet appears in the gain spectrum of a signal field induced by the quantum interference effect from a control field. The ARG can be used not only to completely compensate the Ohmic loss in the NIMM but also to acquire a superluminal group velocity for the SPs. We also show that in the nonlinear propagation regime a huge enhancement of the Kerr nonlinearity of the SPs can be obtained. As a result, ARG-assisted (1 + 1 )- and (2 + 1 )- dimensional superluminal surface polaritonic solitons with extremely low generation power may be produced based on the strong confinement of the electric field at the dielectric-NIMM interface.

Tan, Chaohua; Huang, Guoxiang

2015-02-01

100

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

E-print Network

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, since all physical sources of electromagnetic waves produce radiation fields of finite spatial

Sridhar, Srinivas

101

Translating materials design to the clinic  

NASA Astrophysics Data System (ADS)

Many materials-based therapeutic systems have reached the clinic or are in clinical trials. Here we describe materials design principles and the construction of delivery vehicles, as well as their adaptation and evaluation for human use.

Hubbell, Jeffrey A.; Langer, Robert

2013-11-01

102

Coated nonmagnetic spheres with a negative index of refraction at infrared frequencies Mark S. Wheeler,* J. Stewart Aitchison, and Mohammad Mojahedi  

E-print Network

. Additionally, their inherent anisotropy requires that an isotropic metamaterial have a three-dimensional lattice of micron-scale coated spheres is shown to have an isotropic negative index of refraction been much progress in the development of negative-index metamaterials in the past few years

Mojahedi, Mohammad

103

Designing materials for plasmonic systems  

E-print Network

We use electronic structure calculations based upon density functional theory to search for ideal plasmonic materials among the alkali noble intermetallics. Importantly, we use density functional perturbation theory to calculate the electron-phonon interaction and from there use a first order solution to the Boltzmann equation to estimate the phenomenological damping frequency in the Drude dielectric function. We discuss the necessary electronic features of a plasmonic material and investigate the optical properties of the alkali-noble intermetallics in terms of some generic plasmonic system quality factors. We conclude that at low negative permittivities, KAu with a damping frequency of 0.0224 eV and a high optical gap to bare plasma frequency ratio, outperforms gold and to some extent silver as a plasmonic material. Unfortunately, a low plasma frequency (1.54 eV) reduces its utility in modern plasmonics applications. We also discuss, briefly, the effect of local fields on the optical properties of these mat...

Blaber, Martin G; Ford, Michael J

2009-01-01

104

Mimicry of natural material designs and processes  

Microsoft Academic Search

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

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

1995-01-01

105

Field data reflect improved bit material, design  

SciTech Connect

This article reports on the gains made in polycrystalline diamond compact (PDC) bit improvement as a result of materials and design technology advances in the past five years. It compares actual field performance of the new designs with older bits. Without the advances in materials technology, many of the bit designs now available would not be possible and the full benefits of oil-based mud would not be realized.

Dennis, M.; Kelety, J.T.; Clark, D.A.

1987-09-14

106

Design and Manufacture of Energy Absorbing Materials  

ScienceCinema

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.

Duoss, Eric

2014-05-30

107

Design and Manufacture of Energy Absorbing Materials  

SciTech Connect

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.

Duoss, Eric

2014-05-28

108

OLED microdisplay design and materials  

Microsoft Academic Search

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

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

2010-01-01

109

OLED microdisplay design and materials  

NASA Astrophysics Data System (ADS)

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.

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

2010-04-01

110

4.510/4.501 Materializing Design  

E-print Network

enterprise of design production. MEASUREABLE OUTCOMES - Knowledge of digitally based production systems and logistics of full production are challenged. This part of the course considers materials, finishing, tool, g-code, fabrication logistics and materials - Conceptual understanding on the production of finished

Entekhabi, Dara

111

Designing materials for biology and medicine  

Microsoft Academic Search

Biomaterials have played an enormous role in the success of medical devices and drug delivery systems. We discuss here new challenges and directions in biomaterials research. These include synthetic replacements for biological tissues, designing materials for specific medical applications, and materials for new applications such as diagnostics and array technologies.

Robert Langer; David A. Tirrell

2004-01-01

112

Mimicry of natural material designs and processes  

Microsoft Academic Search

Biological structural materials, although composed of unremarkable substances synthesized at low temperatures, often exhibit\\u000a superior mechanical properties. In particular, the quality in which nearly all biologically derived materials excel is toughness.\\u000a The advantageous mechanical properties are attributable to the hierarchical, composite, structural arrangements common to\\u000a biological systems. Materials scientists and engineers have increasingly recognized that biological designs or processing\\u000a approaches

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

1995-01-01

113

Functionally graded materials: Design, processing and applications  

SciTech Connect

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.

Miyamoto, Y. [ed.] [Osaka Univ. (JP); Kaysser, W.A.; Rabin, B.H.; Kawasaki, A.; Ford, R.G. [eds.

1999-09-01

114

Thermophotovoltaic emitter material selection and design  

SciTech Connect

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.

Saxton, P.C.; Moran, A.L.; Harper, M.J.; Lindler, K.W. [Naval Academy, Annapolis, MD (United States)

1997-07-01

115

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

NASA Astrophysics Data System (ADS)

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.

McDowell, David L.

2007-09-01

116

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

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 Ã? 8.7 cm square

Rogers, John A.

117

Experimental Demonstration of Near-Infrared Negative-Index Metamaterials Shuang Zhang,1  

E-print Network

Materials and Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, New, New York 10027, USA (Received 7 March 2005; published 23 September 2005) Metal-based negative Mexico 87106, USA 2 Department of Applied Physics and Applied Mathematics, Columbia University, New York

New Mexico, University of

118

Carbon nanotube materials characterization and devices design  

NASA Astrophysics Data System (ADS)

The objective of this research is to characterize the electrical and mechanical properties of Carbon Nanotube (CNT) materials, and explore possible device applications for these materials. In order to achieve this goal, different forms of Carbon Nanotube materials---including Carbon Nanotubes, Carbon Nanotube Arrays, Carbon Nanotube Ribbon, Carbon Nanotube Thread, and sub-micrometer Carbon Nanotube Thread---were tested under a Scanning Electron Microscope (SEM) using a Micromanipulator (MM). Video and sound recording of the testing in the microscope provided new understanding how thread is formed and how nanotube materials fail. As-produced and thermally treated nanotubes were also tested. The main electrical parameters measured were electrical resistivity and maximum current density. The main mechanical property measured was strength. Together, these parameters are helping to determine the strongest and most conductive forms of CNT material. Putting nanotube materials into application is the ultimate goal of this continuing research. Several aggressive application ideas were investigated in a preliminary way in this work. In biomedical applications, a bundle of CNTs was formed for use as an electrode for accurate biosensing. A simple robot was designed using CNT electrical fiber. The robot was powered by two solenoids and could act as an in-body sensor and actuator to perform some impossible tasks from the viewpoint of current medical technology. In aerospace engineering, CNT materials could replace copper wire to reduce the weight of aircraft. Based on the excellent mechanical properties of CNT materials, a challenging idea is to use CNT material to build elevators to move payloads to outer space without using rockets. This dissertation makes contributions in the characterization of nanotube materials and in the design of miniature electromagnetic devices.

Li, Weifeng

119

Bistable and Self-Tunable Negative-Index Metamaterial at Optical Frequencies  

NASA Astrophysics Data System (ADS)

We introduce a metamaterial design composed of square plasmonic loops loaded by Kerr nonlinearities that combines enhanced nonlinear response with strong artificial magnetism, ensuring a negative refractive index with bistable and self-tunable response. We verify with full-wave simulations that positive-to-negative switching of refractive index may be obtained with moderate loss. The design of a finite-size metamaterial prism is also presented, supporting at the same frequency, and for the same light intensity, positive or inverted Snell refraction as a function of its previous excitation history.

Chen, Pai-Yen; Farhat, Mohamed; Alù, Andrea

2011-03-01

120

Negative index of refraction microwave frequency structures based on high permittivity inclusions and effective medium theory  

Microsoft Academic Search

A metamaterial designed to have simultaneous negative permittivity and permeability may be built from a cubic lattice of spheres and a three dimensional wire grid embedded in a host medium. Based on reported theory, the spheres must have higher permittivity than the surrounding medium and be smaller than the wavelength of the electromagnetic radiation in the host medium. Metamaterials based

James M. L. Cramer; Andrew J. Gatesman; Robert H. Giles; William E. Nixon

2008-01-01

121

Three-Dimensional Negative Index of Refraction at Optical Frequencies by Coupling Plasmonic Waveguides  

E-print Network

yields a metamaterial consisting of a one-dimensional multilayer stack that exhibits an isotropic index. A metamaterial with an isotropic-loss metamaterial designs operating close to the metal plasma frequency. DOI: 10.1103/PhysRevLett.105.223901 PACS

Polman, Albert

122

High symmetry versus optical isotropy of a negative-index metamaterial  

Microsoft Academic Search

Optically isotropic metamaterials (MMs) are required for the implementation of subwavelength imaging systems. At first glance one would expect that their design should be based on unit cells exhibiting a cubic symmetry being the highest crystal symmetry. It is anticipated that this is a sufficient condition since it is usually assumed that light does not resolve the spatial details of

Christoph Menzel; Carsten Rockstuhl; Rumen Iliew; Falk Lederer; Andrei Andryieuski; Radu Malureanu; Andrei V. Lavrinenko

2010-01-01

123

Real space observation of two-dimensional Bloch wave interferences in a negative index photonic crystal cavity  

NASA Astrophysics Data System (ADS)

We report here the direct observation of two-dimensional (2D) Bloch wave interferences in a negative index photonic crystal by using optical near-field microscopy techniques. The photonic crystal is formed by a defectless honeycomb lattice of air holes etched in III-V semiconductor slab. A scanning near-field optical microscope is used to visualize spatially, as well as spectrally, the light distribution inside the photonic crystal. The recorded near-field spectra and maps presented here unambiguously demonstrate the Bloch wave interferences within the photonic crystal. Then, the spectral and spatial evolution of these interferences allows us to recover experimentally the 2D band diagram of the photonic crystal demonstrating that this structure operates in a negative refraction regime and acts as a left-handed cavity.

Lalouat, Loïc; Cluzel, Benoit; Salomon, Laurent; Dumas, Colette; Seassal, Christian; Louvion, Nicolas; Callard, Ségolène; de Fornel, Frédérique

2008-12-01

124

Design for Engineering Classroom Materials: Unit One  

NSDL National Science Digital Library

These classroom materials for high school students, developed by the Engineering Technology Pathway, integrate critical math, science, and technology knowledge into lessons which ask students to plan, design, test, revise, and implement engineering activities. This first unit (of eight total) gives students introductory material on the history of engineering, the benefits of an engineering career, and different engineering branches. There are PowerPoint presentations, PDF overviews, and student activities in doc format. Three outlines for teaching the unit are also available for download.

125

Saving Material with Systematic Process Designs  

NASA Astrophysics Data System (ADS)

Global competition is forcing the stamping industry to further increase quality, to shorten time-to-market and to reduce total cost. Continuous balancing between these classical time-cost-quality targets throughout the product development cycle is required to ensure future economical success. In today's industrial practice, die layout standards are typically assumed to implicitly ensure the balancing of company specific time-cost-quality targets. Although die layout standards are a very successful approach, there are two methodical disadvantages. First, the capabilities for tool design have to be continuously adapted to technological innovations; e.g. to take advantage of the full forming capability of new materials. Secondly, the great variety of die design aspects have to be reduced to a generic rule or guideline; e.g. binder shape, draw-in conditions or the use of drawbeads. Therefore, it is important to not overlook cost or quality opportunities when applying die design standards. This paper describes a systematic workflow with focus on minimizing material consumption. The starting point of the investigation is a full process plan for a typical structural part. All requirements are definedaccording to a predefined set of die design standards with industrial relevance are fulfilled. In a first step binder and addendum geometry is systematically checked for material saving potentials. In a second step, blank shape and draw-in are adjusted to meet thinning, wrinkling and springback targets for a minimum blank solution. Finally the identified die layout is validated with respect to production robustness versus splits, wrinkles and springback. For all three steps the applied methodology is based on finite element simulation combined with a stochastical variation of input variables. With the proposed workflow a well-balanced (time-cost-quality) production process assuring minimal material consumption can be achieved.

Kerausch, M.

2011-08-01

126

Induced multiferroics: and materials  

E-print Network

of high-frequency impedance ­ e.g. software- defined radio Negative index of refraction for rf antennae Geometrical Scaling, refers to 3-dimensional device structure ("Design Factor") improvements plus other non

Natelson, Douglas

127

Cryogenic laser fusion target material design considerations  

NASA Astrophysics Data System (ADS)

Laser fusion target designs exhibit improved performance when the fusion fuel, a deuterium-tritium (DT) mixture, is frozen into a uniform, solid shell. The formation of such a shell requires rapid isothermal cooling of the target to cryogenic temperatures. The cooling rate must be sufficiently fast to prevent significant, gravitationally driven downward flow of the DT as it passes from the gaseous through the liquid state. Because it is not possible to measure the uniformity of a solid DT layer in opaque, multishell targets, we have modeled such targets to calculate the cooling rate and, hence, the expected thickness uniformity of the DT shell. The presented results provide target designers with practical guidelines for the selection of materials and configurations, which will assist in the fabrication of high-quality cryogenic targets.

Miller, J. R.; Fries, R. J.; Press, W. J.

1979-12-01

128

Use of advanced composite materials for innovative building design solutions/  

E-print Network

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 ...

Lau, Tak-bun, Denvid

2009-01-01

129

Optimized energy harvesting materials and generator design  

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

130

Materials design principles of ancient fish armour  

NASA Astrophysics Data System (ADS)

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.

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

2008-09-01

131

Tools for Material Design and Selection  

NASA Astrophysics Data System (ADS)

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.

Wehage, Kristopher

132

Photovoltaic module encapsulation design and materials selection, volume 1  

Microsoft Academic Search

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

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

1982-01-01

133

A Loop Material Flow System Design for Automated Guided Vehicles  

E-print Network

to a 1 #12;A Loop Material Flow System Design for AGVs 2 half of the total manufacturing costs the modern material handling equipment in manufacturing plants. They are preferred to conveyors due to their exibility, and to robots due to their mobility. The design of the material ow system and its simplicity

Dessouky, Maged

134

Photonic bandgap materials: Design, fabrication, and characterization  

Microsoft Academic Search

The last few decades have seen a tremendous explosion in the area of new synthetic materials. As we begin to better understand the nature of the atomic and molecular bonds it has been possible to systematically search for materials with specific properties thanks to the availability of powerful supercomputers. Due to significant advances in materials synthesis a rich variety of

Ganapathi S. Subramania

2000-01-01

135

FOREWORD: Computational methodologies for designing materials Computational methodologies for designing materials  

NASA Astrophysics Data System (ADS)

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

Rahman, Talat S.

2009-02-01

136

Piezoactuator Design Considering the Optimum Placement of FGM Piezoelectric Material  

E-print Network

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

Paulino, Glaucio H.

137

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

Code of Federal Regulations, 2014 CFR

... 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...

2014-10-01

138

Digital Material Samples for Design A DISSERTATION  

E-print Network

these materials. We build interactive programs for selecting paints samples and interpolating metallic paint colors and we develop a new ap- proach to morphing surface light fields to meld these materials together with a user study and report the results. The second tool allows for the creation of new metallic paint colors

Meyer, Gary

139

Thermal Characterization of Functionally Graded Materials: Design of Optimum Experiments  

NASA Technical Reports Server (NTRS)

This paper is a study of optimal experiment design applied to the measure of thermal properties in functionally graded materials. As a first step, a material with linearly-varying thermal properties is analyzed, and several different tran- sient experimental designs are discussed. An optimality criterion, based on sen- sitivity coefficients, is used to identify the best experimental design. Simulated experimental results are analyzed to verify that the identified best experiment design has the smallest errors in the estimated parameters. This procedure is general and can be applied to design of experiments for a variety of materials.

Cole, Kevin D.

2003-01-01

140

Materials 4: Design Strategies for Transformative Innovation  

NSDL National Science Digital Library

What can we learn from nature's designs for sustainability? This video compares nature's methods with the industrial era methods of design. It recommends a design strategy based on the connection or relationship between things as a means to achieve transformative innovation for sustainability. This video is part of the Sustainability Learning Suites, made possible in part by a grant from the National Science Foundation. See 'Learn more about this resource' for Learning Objectives and Activities.

2012-12-19

141

Design and fabrication of materials with desired deformation behavior  

Microsoft Academic Search

This paper introduces a data-driven process for designing and fab- ricating materials with desired deformation behavior. Our process starts with measuring deformation properties of base materials. For each base material we acquire a set of example deformations, and we represent the material as a non-linear stress-strain relationship in a finite-element model. We have validated our material measure- ment process by

Bernd Bickel; Moritz Bächer; Miguel A. Otaduy; Hyunho Richard Lee; Hanspeter Pfister; Markus H. Gross; Wojciech Matusik

2010-01-01

142

Design and fabrication of materials with desired deformation behavior  

Microsoft Academic Search

This paper introduces a data-driven process for designing and fabricating materials with desired deformation behavior. Our process starts with measuring deformation properties of base materials. For each base material we acquire a set of example deformations, and we represent the material as a non-linear stress-strain relationship in a finite-element model. We have validated our material measurement process by comparing simulations

Bernd Bickel; Moritz Bächer; Miguel A. Otaduy; Hyunho Richard Lee; Hanspeter Pfister; Markus Gross; Wojciech Matusik

2010-01-01

143

Synthesis and design of silicide intermetallic materials  

SciTech Connect

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.

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

1998-11-01

144

Design for containment of hazardous materials  

SciTech Connect

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.

Murray, R.C. (Lawrence Livermore National Lab., CA (United States)); McDonald, J.R. (Texas Tech Univ., Lubbock, TX (United States))

1991-03-01

145

Evaluating Course Design Principles for Multimedia Learning Materials  

ERIC Educational Resources Information Center

Purpose: This paper aims to report on evaluation studies of principles of course design for interactive multimedia learning materials. Design/methodology/approach: At the Defence Academy of the UK, Cranfield University has worked with military colleagues to produce multimedia learning materials for courses on "Military Knowledge". The courses are…

Scott, Bernard; Cong, Chunyu

2010-01-01

146

Reticular synthesis and the design of new materials  

Microsoft Academic Search

The long-standing challenge of designing and constructing new crystalline solid-state materials from molecular building blocks is just beginning to be addressed with success. A conceptual approach that requires the use of secondary building units to direct the assembly of ordered frameworks epitomizes this process: we call this approach reticular synthesis. This chemistry has yielded materials designed to have predetermined structures,

Michael O'Keeffe; Nathan W. Ockwig; Hee K. Chae; Mohamed Eddaoudi; Jaheon Kim; Omar M. Yaghi

2003-01-01

147

Decision support system for material handling and packaging design  

Microsoft Academic Search

The reliability of the materials handling process involving automated stacking of packages on a pallet or automated sorting of packages in a distribution system depends mainly on the design of the package and the material used for the package. Many problems can be eliminated that result in a higher utilization of the system if the package is designed not only

Mats I. Johnsson; Abdel K. Mazouz; Chingping Han

1992-01-01

148

Material transformation designing shape changing interfaces enabled by programmable material anisotropy  

E-print Network

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 ...

Ou, Jifei

2014-01-01

149

Bridge : information as material for design  

E-print Network

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 ...

Kaijima, Sawako, 1976-

2005-01-01

150

Concurrent materials and process selection in conceptual design  

SciTech Connect

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.

Kleban, S.D.

1998-07-01

151

Material Design, Selection, and Manufacturing Methods for System Sustainment  

SciTech Connect

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.

David Sowder, Jim Lula, Curtis Marshall

2010-02-18

152

Material Compatibility with Space Storable Propellants. Design Guidebook  

NASA Technical Reports Server (NTRS)

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.

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

1972-01-01

153

Stochastic Analysis and Design of Heterogeneous Microstructural Materials System  

NASA Astrophysics Data System (ADS)

Advanced materials system refers to new materials that are comprised of multiple traditional constituents but complex microstructure morphologies, which lead to superior properties over the conventional materials. To accelerate the development of new advanced materials system, the objective of this dissertation is to develop a computational design framework and the associated techniques for design automation of microstructure materials systems, with an emphasis on addressing the uncertainties associated with the heterogeneity of microstructural materials. Five key research tasks are identified: design representation, design evaluation, design synthesis, material informatics and uncertainty quantification. Design representation of microstructure includes statistical characterization and stochastic reconstruction. This dissertation develops a new descriptor-based methodology, which characterizes 2D microstructures using descriptors of composition, dispersion and geometry. Statistics of 3D descriptors are predicted based on 2D information to enable 2D-to-3D reconstruction. An efficient sequential reconstruction algorithm is developed to reconstruct statistically equivalent random 3D digital microstructures. In design evaluation, a stochastic decomposition and reassembly strategy is developed to deal with the high computational costs and uncertainties induced by material heterogeneity. The properties of Representative Volume Elements (RVE) are predicted by stochastically reassembling SVE elements with stochastic properties into a coarse representation of the RVE. In design synthesis, a new descriptor-based design framework is developed, which integrates computational methods of microstructure characterization and reconstruction, sensitivity analysis, Design of Experiments (DOE), metamodeling and optimization the enable parametric optimization of the microstructure for achieving the desired material properties. Material informatics is studied to efficiently reduce the dimension of microstructure design space. This dissertation develops a machine learning-based methodology to identify the key microstructure descriptors that highly impact properties of interest. In uncertainty quantification, a comparative study on data-driven random process models is conducted to provide guidance for choosing the most accurate model in statistical uncertainty quantification. Two new goodness-of-fit metrics are developed to provide quantitative measurements of random process models' accuracy. The benefits of the proposed methods are demonstrated by the example of designing the microstructure of polymer nanocomposites. This dissertation provides material-generic, intelligent modeling/design methodologies and techniques to accelerate the process of analyzing and designing new microstructural materials system.

Xu, Hongyi

154

Designing Educative Curriculum Materials: A Theoretically and Empirically Driven Process  

ERIC Educational Resources Information Center

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…

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

2014-01-01

155

Structural design for non-linear metallic materials  

Microsoft Academic Search

The material stress–strain behaviour of structural carbon steel may be suitably accurately reflected for design purposes by an idealised elastic, perfectly-plastic material model; such material behaviour lends itself to the concept of section classification. There are, however, a number of structural materials, such as aluminium, stainless steel and some high strength, cold-worked steels, where this idealised model becomes inaccurate due

Leroy Gardner; Mahmud Ashraf

2006-01-01

156

Computational materials design for energy applications  

NASA Astrophysics Data System (ADS)

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.

Ozolins, Vidvuds

2013-03-01

157

"Safety Concrete" A Material Designed to Fail  

E-print Network

sand #12;Design Variables Composition Variables Processing Variables Binder composition · Slag, OPC, CKD Activator · sodium silicate, NaOH, CaCl2 Sand/binder ratio Water/binder ratio Cure (hydration Strength > 1000 psi > 90% Impact Behavior (weight % of particles 2000 psi > 95% #12

158

Designing Training Materials for Developing Countries.  

ERIC Educational Resources Information Center

Describes four training guides developed by the Water and Sanitation for Health Project for use in rural water supply and sanitation projects in developing countries, explains the development process, offers insights gained from the process, and presents five considerations for designing training in third world countries. (MBR)

Rosenweig, Fred

1984-01-01

159

Designing colloidal suspensions for directed materials assembly  

SciTech Connect

Recent advances in microfluidic and direct-write assembly of colloidal suspensions open new avenues for microscale patterning of functional materials with controlled composition, geometry, and properties. In this article, we describe fundamental aspects of suspension structure, elasticity, and flow behavior for three important systems: (1) dense liquids (and glasses), (2) gels, and (3) biphasic mixtures. We also highlight examples from the current literature of colloidal architectures patterned by these emerging methods.

Conrad, Jacinta C; Ferreira, Summer R; Yoshikawa, Jun; Shepherd, Robert F; Ahn, Bok Y; Lewis, Jennifer A

2011-01-01

160

Nondestructive evaluation of composite materials - A design philosophy  

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

161

Designing chromonic mesogens for the fabrication of anisotropic optical materials  

NASA Astrophysics Data System (ADS)

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.

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

2008-02-01

162

Design with brittle materials - An interdisciplinary educational program  

NASA Technical Reports Server (NTRS)

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.

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

163

Metallo-dielectric core--shell nanospheres as building blocks for optical three-dimensional isotropic negative-index metamaterials  

Microsoft Academic Search

Materials showing electromagnetic properties that are not attainable in naturally occurring media, so-called metamaterials, have been lately, and still are, among the most active topics in optical and materials physics and engineering. Among these properties, one of the most attractive ones is the sub-diffraction resolving capability predicted for media having an index of refraction of -1. Here, we propose a

R. Paniagua-Domínguez; F. López-Tejeira; R. Marqués; J. A. Sánchez-Gil

2011-01-01

164

The automated design of materials far from equilibrium  

NASA Astrophysics Data System (ADS)

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.

Miskin, Marc Z.

165

Designing Radiation Resistance in Materials for Fusion Energy  

NASA Astrophysics Data System (ADS)

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.

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

2014-07-01

166

Photovoltaic-module encapsulation design and materials selection: Volume 1  

SciTech Connect

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.

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

1982-06-01

167

First Principles Modeling for Research and Design of New Materials  

E-print Network

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 ...

Ceder, Gerbrand

168

Material evaluation and selection processes to enable design for manufacture  

E-print Network

In order to optimize product designs it is necessary to quickly evaluate many candidate materials in terms of performance and processing costs. Evaluation using physical prototypes yields concrete results but is time ...

Abler, Craig Bennett, 1975-

2006-01-01

169

Optimal Design and Scheduling of Unsteady State Material Recovery Networks  

E-print Network

methodologies: the first is a hierarchical multi-step methodology developed for the design and scheduling of batch water (material of interest) recycle networks. A new source- double tank-sink arrangement is introduced to overcome the limitation of samecycle...

Rabie, Arwa H.

2010-01-14

170

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

Code of Federal Regulations, 2013 CFR

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

2013-10-01

171

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

Code of Federal Regulations, 2011 CFR

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

2011-10-01

172

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

Code of Federal Regulations, 2012 CFR

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

2012-10-01

173

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

Code of Federal Regulations, 2010 CFR

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

2010-10-01

174

Evaluation of materials and design modifications for aircraft brakes  

NASA Technical Reports Server (NTRS)

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.

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

1975-01-01

175

Center for Intelligent Fuel Cell Materials Design  

SciTech Connect

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.

Santurri, P.R., (Chemsultants International); Hartmann-Thompson, C.; Keinath, S.E. (Michigan Molecular Inst.)

2008-08-26

176

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

ERIC Educational Resources Information Center

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…

Dubocq, Edward R.

177

Exascale Co-Design Center for Materials In Extreme Environments  

E-print Network

/SC/ASCR Co-Design Centers App SW M iddlew are Sim ulators, PrototypesHW Domain workload Functional ExascaleExascale Co-Design Center for Materials In Extreme Environments Timothy Germann, tcg@lanl.gov Large physics refinement. · Our vision is an uncertainty quantification (UQ) driven adaptive physics refinement

178

Piezoactuator design considering the optimum placement of FGM piezoelectric material  

NASA Astrophysics Data System (ADS)

Functionally Graded Materials (FGMs) possess continuous variation of material properties and are characterized by spatially varying microstructures. Recently, the FGM concept has been explored in piezoelectric materials to improve properties and to increase the lifetime of piezoelectric actuators. Elastic, piezoelectric, and dielectric properties are graded along the thickness of a piezoceramic FGM. Thus, the gradation of piezoceramic properties can influence the performance of piezoactuators, and an optimum gradation can be sought through optimization techniques. However, the design of these FGM piezoceramics are usually limited to simple shapes. An interesting approach to be investigated is the design of FGM piezoelectric mechanisms which essentially can be defined as a FGM structure with complex topology made of piezoelectric and non-piezoelectric material that must generate output displacement and force at a certain specified point of the domain and direction. This can be achieved by using topology optimization method. Thus, in this work, a topology optimization formulation that allows the simultaneous distribution of void and FGM piezoelectric material (made of piezoelectric and non-piezoelectric material) in the design domain, to achieve certain specified actuation movements, will be presented. The method is implemented based on the SIMP material model where fictitious densities are interpolated in each finite element, providing a continuum material distribution in the domain. The optimization algorithm employed is based on sequential linear programming (SLP) and the finite element method is based on the graded finite element concept where the properties change smoothly inside the element. This approach provides a continuum approximation of material distribution, which is appropriate to model FGMs. Some FGM piezoelectric mechanisms were designed to demonstrate the usefulness of the proposed method. Examples are limited to two-dimensional models, due to FGM manufacturing constraints and the fact that most of the applications for such FGM piezoelectric mechanisms are planar devices. An one-dimensional constraint of the material gradation is imposed to provide more realistic designs.

Carbonari, Ronny C.; Nishiwaki, Shinji; Paulino, Glaucio H.; Nelli Silva, Emílio C.

2007-04-01

179

Structure-based design of functional amyloid materials.  

PubMed

Amyloid fibers, once exclusively associated with disease, are acquiring utility as a class of biological nanomaterials. Here we introduce a method that utilizes the atomic structures of amyloid peptides, to design materials with versatile applications. As a model application, we designed amyloid fibers capable of capturing carbon dioxide from flue gas, to address the global problem of excess anthropogenic carbon dioxide. By measuring dynamic separation of carbon dioxide from nitrogen, we show that fibers with designed amino acid sequences double the carbon dioxide binding capacity of the previously reported fiber formed by VQIVYK from Tau protein. In a second application, we designed fibers that facilitate retroviral gene transfer. By measuring lentiviral transduction, we show that designed fibers exceed the efficiency of polybrene, a commonly used enhancer of transduction. The same procedures can be adapted to the design of countless other amyloid materials with a variety of properties and uses. PMID:25474758

Li, Dan; Jones, Eric M; Sawaya, Michael R; Furukawa, Hiroyasu; Luo, Fang; Ivanova, Magdalena; Sievers, Stuart A; Wang, Wenyuan; Yaghi, Omar M; Liu, Cong; Eisenberg, David S

2014-12-31

180

Optimum place of piezoelectric material in the piezoactuator design  

NASA Astrophysics Data System (ADS)

Piezoelectric actuators offer significant promise in a wide range of applications. The piezoelectric actuators considered in this work essentially consist of a flexible structure actuated by piezoceramics that must generate output displacement and force at a certain specified point of the domain and direction. The flexible structure acts as a mechanical transformer by amplifying and changing the direction of piezoceramics output displacements. The design of these piezoelectric actuators are complex and a systematic design method, such as topology optimization has been successfully applied in the latest years, with appropriate formulation of the optimization problem to obtain optimized designs. However, in these previous design formulations, piezoceramics position are usually kept fixed in the design domain and only the flexible structure is designed by distributing only some non-piezoelectric material (Aluminum, for example). This imposes a constraint in the position of piezoelectric material in the optimization problem limiting the optimality of the solution. Thus, in this work, a formulation that allows the simultaneous search for an optimal topology of a flexible structure as well as the optimal positions of the piezoceramics in the design domain, to achieve certain specified actuation movements, will be presented. This can be achieved by allowing the simultaneous distribution of non-piezoelectric and piezoelectric material in the design domain. The optimization problem is posed as the design of a flexible structure together with optimum positions of piezoelectric material that maximizes output displacements or output forces in a certain specified direction and point of the domain. The method is implemented based on the SIMP material model where fictitious densities are interpolated in each finite element, providing a continuum material distribution in the domain. Presented examples are limited to two-dimensional models, once most of the applications for such piezoelectric actuators are planar devices.

Carbonari, Ronny C.; Nishiwaki, Shinji; Silva, Emílio C. N.

2006-03-01

181

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

NASA Technical Reports Server (NTRS)

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.

Inman, Daniel J.; Cudney, Harley H.

2000-01-01

182

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

E-print Network

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 ...

Coelho, Marcelo

2008-01-01

183

A design pathfinder with material correlation points for inflatable systems  

NASA Astrophysics Data System (ADS)

The incorporation of inflatable structures into aerospace systems can produce significant advantages in stowed volume to mechanical effectiveness and overall weight. Many applications of these ultra-lightweight systems are designed to precisely control internal or external surfaces, or both, to achieve desired performance. The modeling of these structures becomes complex due to the material nonlinearities inherent to the majority of construction materials used in inflatable structures. Furthermore, accurately modeling the response and behavior of the interfacing boundaries that are common to many inflatable systems will lead to better understanding of the entire class of structures. The research presented involved using nonlinear finite element simulations correlated with photogrammetry testing to develop a procedure for defining material properties for commercially available polyurethane-coated woven nylon fabric, which is representative of coated materials that have been proven materials for use in many inflatable systems. Further, the new material model was used to design and develop an inflatable pathfinder system which employs only internal pressure to control an assembly of internal membranes. This canonical inflatable system will be used for exploration and development of general understanding of efficient design methodology and analysis of future systems. Canonical structures are incorporated into the design of the phased pathfinder system to allow for more universal insight. Nonlinear finite element simulations were performed to evaluate the effect of various boundary conditions, loading configurations, and material orientations on the geometric precision of geometries representing typical internal/external surfaces commonly incorporated into inflatable pathfinder system. The response of the inflatable system to possible damage was also studied using nonlinear finite element simulations. Development of a correlated material model for analysis of the inflatable pathfinder system has improved the efficiency of design and analysis techniques of future inflatable structures. KEYWORDS: Nonlinear Finite Element, Inflatable Structures, Gossamer Space Systems, Photogrammetry Measurements, Coated Woven Fabric.

Fulcher, Jared Terrell

184

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

NASA Astrophysics Data System (ADS)

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.

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

2015-01-01

185

Teaching-Material Crystallization: Wiki-based Rapid Prototyping for Teaching-Material Design  

Microsoft Academic Search

To support individualized and adaptive learning, teachers are encouraged to develop various teaching materials according to different requirements. However, traditional methodologies for designing teaching materials are time-consuming. To speed up the development process of teaching materials, our idea is to use a rapid prototyping approach which is based on automatic draft generation and Wiki-based revision. Since the Wiki-based authoring is

Wen-Chung Shih; Shian-Shyong Tseng; Jui-Feng Weng

186

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

SciTech Connect

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.

Stephanie Austad

2010-06-01

187

Optimal design of piezoelectric materials and devices for energy harvesting  

NASA Astrophysics Data System (ADS)

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.

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

2013-06-01

188

Energy flux pattern of inverse Goos-Hanchen shift in photonic crystals with negative index of refraction  

E-print Network

The energy flux patterns of inverse Goos-Hanchen (GH) shift around the interface between air and negatively refractive photonic crystal (NRPhC) with different surface terminations is investigated. Results show that NRPhC exhibits inverse GH shift in TM and TE polarization, and the localization and pattern of energy flux differ in TM and TE polarizations and are strongly affected by surface termination. This is different to the condition of negative permittivity materials (i.e., metal), which only presents inverse GH shift in TM polarization. In the case of TE polarization, the energy flux pattern exhibits the flux of backward wave whose localization changes from the surface to inside of NRPhC with the variation of surface termination. In the case of TM polarization, the energy flux pattern is always confined within the surface of NRPhC, whereas its pattern changes from the flux of backward wave to vortices at the surface of NRPhC, which is different to the energy flux of TM polarization of metal. By properly ...

Hu, Jinbing; Chen, Jiabi; Jiang, Qiang; Wang, Yan; Zhuang, Songlin

2015-01-01

189

Intelligent design of cutting tools using smart material  

Microsoft Academic Search

Shaving metal from a workpiece to produce desired geometric shape is carried out in turning machine tool. Attenuating a micro\\u000a level vibration of a cutting tool using smart materials can save old machines and enhance flexibility in designing new generations\\u000a of machine tools. The finite element method is employed to investigate structural stiffness, damping, and switching methodology\\u000a using smart material

Maki K. Rashid; Khalil Ibrahim Shihab

2006-01-01

190

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

Code of Federal Regulations, 2011 CFR

...non-vital systems-materials and pressure design. 128.220 Section 128...EQUIPMENT AND SYSTEMS Materials and Pressure Design § 128.220 Class II non-vital systems—materials and pressure design. (a) Except as...

2011-10-01

191

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

Code of Federal Regulations, 2011 CFR

...and watertight bulkheads-materials and pressure design. 128.230 Section 128...EQUIPMENT AND SYSTEMS Materials and Pressure Design § 128.230 Penetrations of...watertight bulkheads—materials and pressure design. (a) Each piping...

2011-10-01

192

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

Code of Federal Regulations, 2014 CFR

...and watertight bulkheads-materials and pressure design. 128.230 Section 128...EQUIPMENT AND SYSTEMS Materials and Pressure Design § 128.230 Penetrations of...watertight bulkheads—materials and pressure design. (a) Each piping...

2014-10-01

193

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

Code of Federal Regulations, 2010 CFR

...non-vital systems-materials and pressure design. 128.220 Section 128...EQUIPMENT AND SYSTEMS Materials and Pressure Design § 128.220 Class II non-vital systems—materials and pressure design. (a) Except as...

2010-10-01

194

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

Code of Federal Regulations, 2010 CFR

...and watertight bulkheads-materials and pressure design. 128.230 Section 128...EQUIPMENT AND SYSTEMS Materials and Pressure Design § 128.230 Penetrations of...watertight bulkheads—materials and pressure design. (a) Each piping...

2010-10-01

195

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

Code of Federal Regulations, 2014 CFR

...non-vital systems-materials and pressure design. 128.220 Section 128...EQUIPMENT AND SYSTEMS Materials and Pressure Design § 128.220 Class II non-vital systems—materials and pressure design. (a) Except as...

2014-10-01

196

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

Code of Federal Regulations, 2013 CFR

...and watertight bulkheads-materials and pressure design. 128.230 Section 128...EQUIPMENT AND SYSTEMS Materials and Pressure Design § 128.230 Penetrations of...watertight bulkheads—materials and pressure design. (a) Each piping...

2013-10-01

197

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

Code of Federal Regulations, 2012 CFR

...non-vital systems-materials and pressure design. 128.220 Section 128...EQUIPMENT AND SYSTEMS Materials and Pressure Design § 128.220 Class II non-vital systems—materials and pressure design. (a) Except as...

2012-10-01

198

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

Code of Federal Regulations, 2013 CFR

...non-vital systems-materials and pressure design. 128.220 Section 128...EQUIPMENT AND SYSTEMS Materials and Pressure Design § 128.220 Class II non-vital systems—materials and pressure design. (a) Except as...

2013-10-01

199

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

Code of Federal Regulations, 2012 CFR

...and watertight bulkheads-materials and pressure design. 128.230 Section 128...EQUIPMENT AND SYSTEMS Materials and Pressure Design § 128.230 Penetrations of...watertight bulkheads—materials and pressure design. (a) Each piping...

2012-10-01

200

Concurrent materials and process selection in conceptual design  

SciTech Connect

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.

Kleban, Stephen D.; Knorovsky, Gerald A.

2000-08-16

201

Designer disordered materials with large, complete photonic band gaps  

PubMed Central

We present designs of 2D, isotropic, disordered, photonic materials of arbitrary size with complete band gaps blocking all directions and polarizations. The designs with the largest band gaps are obtained by a constrained optimization method that starts from a hyperuniform disordered point pattern, an array of points whose number variance within a spherical sampling window grows more slowly than the volume. We argue that hyperuniformity, combined with uniform local topology and short-range geometric order, can explain how complete photonic band gaps are possible without long-range translational order. We note the ramifications for electronic and phononic band gaps in disordered materials. PMID:19918087

Florescu, Marian; Torquato, Salvatore; Steinhardt, Paul J.

2009-01-01

202

LUTE primary mirror materials and design study report  

NASA Technical Reports Server (NTRS)

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.

Ruthven, Greg

1993-01-01

203

The Cam Shell: An Innovative Design With Materials and Manufacturing  

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

204

Photovoltaic module encapsulation design and materials selection. Volume II  

Microsoft Academic Search

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

Cuddihy

1984-01-01

205

Socio-material design for computer mediated social sensemaking  

E-print Network

visible to a trained team of analysts. One approach to solving these interpretation problems is throughSocio-material design for computer mediated social sensemaking Abstract Telemonitoring healthcare telemonitoring's ability both to deliver cost savings and to provide a scalable solution to escalating healthcare

Edinburgh, University of

206

Materials Process Design and Control Laboratory Cornell University  

E-print Network

remediation, nuclear contamination and enhanced oil recovery Availability of enough input data and comparative results Pose and solve questions that provide some insight Ground water remediation and contamination control Oil recovery #12;Materials Process Design and Control Laboratory Cornell University Proposed

Zabaras, Nicholas J.

207

Advanced High Temperature Turbine Seals Materials and Designs  

Microsoft Academic Search

Advanced turbine seal materials and designs are under development to achieve higher temperature capability, extended lifetime and reliability than the state of the art technology. Cooling air consumption, inspection cycles interval and repair costs of aero engines have to be reduced. In the following, results of a program funded by the European Community under the \\

W. Smarsly; N. Zheng; C. S. Buchheim; C. Nindel; C. Silvestro; D. Sporer; M. Tuffs; K. Schreiber; C. Langlade-Bomba; Olaf Andersen; H. Goehler; N. J. Simms; Gordon M. McColvin

2005-01-01

208

Reticular synthesis and the design of new materials  

E-print Network

of solid-state materials: we refer to its implementation as reticular synthesis. In essence, reticular, it generally remains more of an art than a science--in that the discovery of new compounds has mostly been of the required building blocks for its assembly. This process is central to our ability to achieve true design

Yaghi, Omar M.

209

The application of composite materials to spaceborne radiometer instrument design  

Microsoft Academic Search

The stability and coregistration requirements for future radiometric instrument designs spawn the need for a totally integrated instrument structure and thermal control scheme. To meet the requirements of the future Geostationary meteorological missions an Ultra Stable Instrument Structure (USIS) will be needed. An instrument structure of lightweight construction is described that takes advantage of composite materials that combine high stiffness,

Robert A. Hookman; George E. Zurmehly

1990-01-01

210

CubeSat Material Limits for Design for Demise  

NASA Technical Reports Server (NTRS)

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.

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

2014-01-01

211

CubeSat Material Limits For Design for Demise  

NASA Technical Reports Server (NTRS)

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.

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

2014-01-01

212

A design of flexible riser pipe with composite material  

SciTech Connect

The application of flexible riser pipe to use at sea depths of over 1,000 m is limited by the tension of the pipe itself. Thus there is a need for lighter-weight flexible riser pipe for offshore oil development at great ocean depths. In one design for lightweight flexible riser pipe, the tensile reinforcement is replaced with a composite material. But the design of such pipe must take into account the fact that its tensile reinforcement is subject to superimposition of both the static load due to its own weight and the inner pressure, and the dynamic load due to waves and ocean currents. This report discusses the design of the tensile reinforcement, with an emphasis on the Goodman`s diagram of the composite material.

Makino, Y.; Fuku, T.; Ishii, K. [Furukawa Electric Co., Ltd., Chiba (Japan); Yoshizawa, M.; Wada, H. [Japan National Oil Corp., Chiba (Japan)

1995-12-31

213

The design and modeling of periodic materials with novel properties  

NASA Astrophysics Data System (ADS)

Cellular materials are ubiquitous in our world being found in natural and engineered systems as structural materials, sound and energy absorbers, heat insulators and more. Stochastic foams made of polymers, metals and even ceramics find wide use due to their novel properties when compared to monolithic materials. Properties of these so called hybrid materials, those that combine materials or materials and space, are derived from the localization of thermomechanical stresses and strains on the mesoscale as a function of cell topology. The effects of localization can only be generalized in stochastic materials arising from their inherent potential complexity, possessing variations in local chemistry, microstructural inhomogeneity and topological variations. Ordered cellular materials on the other hand, such as lattices and honeycombs, make for much easier study, often requiring analysis of only a single unit-cell. Theoretical bounds predict that hybrid materials have the potential to push design envelopes offering lighter stiffer and stronger materials. Hybrid materials can achieve very low and even negative coefficients of thermal expansion (CTE) while retaining a relatively high stiffness -- properties completely unmatched by monolithic materials. In the first chapter of this thesis a two-dimensional lattice is detailed that possess near maximum stiffness, relative to the tightest theoretical bound, and low, zero and even appreciably negative thermal expansion. Its CTE and stiffness are given in closed form as a function of geometric parameters and the material properties. This result is confirmed with finite elements (FE) and experiment. In the second chapter the compressive stiffness of three-dimensional ordered foams, both closed and open cell, are predicted with FE and the results placed in property space in terms of stiffness and density. A novel structure is identified that effectively achieves theoretical bounds for Young's, shear and bulk modulus simultaneously, over a wide range of relative densities, greatly expanding the property space of available materials with a pragmatic manufacturable structure. A variety of other novel and previously studied ordered foam topologies are also presented that are largely representative of the spectrum of performance of such materials, shedding insight into the behavior of all cellular materials.

Berger, Jonathan Bernard

214

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

SciTech Connect

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.

Shappert, L.B.; Bowman, S.M. [Oak Ridge National Lab., TN (United States); Arnold, E.D. [Lockheed Martin Energy Systems, Oak Ridge, TN (United States)] [and others

1998-08-01

215

Thermal design of composite material high temperature attachments  

NASA Technical Reports Server (NTRS)

An evaluation has been made of the thermal aspects of utilizing advanced filamentary composite materials as primary structures on the shuttle vehicle. The technical objectives of this study are to: (1) establish and design concepts for maintaining material temperatures within allowable limits at TPS attachments and or penetrations applicable to the space shuttle; and (2) verify the thermal design analysis by testing selected concepts. Specific composite materials being evaluated are boron epoxy, graphite/epoxy, boron polyimide, and boron aluminum; graphite/polyimide has been added to this list for property data identification and preliminary evaluation of thermal design problems. The TPS standoff to composite structure attachment over-temperature problem is directly related to TPS maximum surface temperature. To provide a thermally comprehensive evaluation of attachment temperature characteristics, maximum surface temperatures of 900 F, 1200 F, 1800 F, 2500 F and 3000 F are considered in this study. This range of surface temperatures and the high and low maximum temperature capability of the selected composite materials will result in a wide range of thermal requirements for composite/TPS standoff attachments.

1972-01-01

216

Porous materials with high negative Poisson’s ratios—a mechanism based material design  

NASA Astrophysics Data System (ADS)

In an effort to tailor functional materials with customized anisotropic properties—stiffness and yield strain, we propose porous materials consisting of flexible mesostructures designed from the deformation of a re-entrant auxetic honeycomb and compliant mechanisms. Using an analogy between compliant mechanisms and a cellular material’s deformation, we can tailor the in-plane properties of mesostructures; low stiffness and high strain in one direction and high stiffness and low strain in the other direction. An analytical model is developed to obtain the effective moduli and yield strains of the porous materials by combining the kinematics of a rigid link mechanism and deformation of flexure hinges. A numerical technique is implemented with the analytical model for the nonlinear constitutive relations of the mesostructures and their strain-dependent Poisson’s ratios. A finite element analysis (FEA) is used to validate the analytical and numerical models. The designed moduli and yield strain of porous materials with an aluminum alloy are 2 GPa and 0.28% in one direction and 0.2 MPa and 28% in the other direction. These porous materials with mesostructures have high negative Poisson’s ratios, {\

Kim, Kwangwon; Ju, Jaehyung; Kim, Doo-Man

2013-08-01

217

Designed amyloid fibers as materials for selective carbon dioxide capture.  

PubMed

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

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

2014-01-01

218

Designed amyloid fibers as materials for selective carbon dioxide capture  

PubMed Central

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

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

2014-01-01

219

Photovoltaic module encapsulation design and materials selection. Volume II  

SciTech Connect

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.

Cuddihy, E.

1984-06-01

220

Design of a materials testing experiment for the INTOR  

SciTech Connect

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.

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

1981-08-28

221

A model for designing functionally gradient material joints  

SciTech Connect

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.

Messler, R.W. Jr.; Jou, M.; Orling, T.T. [Rensselaer Polytechnic Inst., Troy, NY (United States)

1995-05-01

222

Rational Design of Pathogen-Mimicking Amphiphilic Materials as Nanoadjuvants  

NASA Astrophysics Data System (ADS)

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.

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

223

Rational Design of Pathogen-Mimicking Amphiphilic Materials as Nanoadjuvants  

PubMed Central

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. PMID:22355713

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

2011-01-01

224

Design and engineering analysis of material procurement mobile operation platform  

NASA Astrophysics Data System (ADS)

The material procurement mobile operation platform (MPMOP) consists of six modules, including network operation, truck transportation, remote communication, satellite positioning, power supply and environment regulation. The MPMOP is designed to have six major functions, including online procurement, command control, remote communication, satellite positioning, information management and auxiliary decision. The paper implements an engineering analysis on the MPMOP from three aspects, including transportation transfinite, centroid, and power dissipation.

Ding, H.; Li, J.

2014-03-01

225

Thermo-magnetic materials for use in designing intelligent actuators  

SciTech Connect

The authors present the concept of an intelligent thermal actuator designed by using thermally sensitive magnetic materials. The use of the magnetic transition of FeRh alloy is very effective in increasing the actuator functions. These functions are freedom of direction, tuning temperature, and increasing both sensitivity and power. Two new types of actuator, a remote controlled optical driven thermo-magnetic motor and a temperature sensitive spring-less valve, are proposed and experimental results are shown.

Ohtani, Yoshimutsu; Yoshimura, Fumikatsu; Hatakeyama, Iwao [NTT Interdisciplinary Research Labs., Tokai, Ibaraki (Japan); Ishii, Yoshikazu [NTT Interdisciplinary Research Labs., Musashino, Tokyo (Japan)

1994-12-31

226

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

SciTech Connect

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.

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

2005-01-01

227

Design of standards for nondestructive assay of special nuclear material  

SciTech Connect

Nondestructive assay (NDA) of special nuclear material (SNM) involves a variety of measurement techniques, instruments, and nuclear materials. High-quality measurements require well-characterized SNM standards that represent the expected range of mass, chemical composition, and physical properties of the SNM to be measured. Due to the very limited commercial availability of NDA standards, facilities must usually produce their own standards, both to meet their specific measurement needs and to comply with existing regulations. This paper will describe the current extent to which NDA standards are commercially available. The authors will further describe the types of NDA standards used to calibrate and verify the measurement techniques commonly used in the safeguards of SNM. Several types of NDA standards will be discussed in detail to illustrate the considerations that go into specifying and designing traceable, representative standards for materials accounting measurements.

Smith, H.A. Jr.; Stewart, J.E. [Los Alamos National Lab., NM (United States); Ruhter W. [Lawrence Livermore National Lab., CA (United States)

1997-05-01

228

Design And Formability Of A New Composite Material  

NASA Astrophysics Data System (ADS)

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.

Bolay, C.; Liewald, M.

2011-05-01

229

Design And Formability Of A New Composite Material  

SciTech Connect

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.

Bolay, C.; Liewald, M. [Institute for Metal Forming Technology (IFU)-Holzgartenstr. 17, 70174 Stuttgart (Germany)

2011-05-04

230

Design and preparation of materials for advanced electrochemical storage.  

PubMed

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

Melot, Brent C; Tarascon, J-M

2013-05-21

231

Textile Materials for the Design of Wearable Antennas: A Survey  

PubMed Central

In the broad context of Wireless Body Sensor Networks for healthcare and pervasive applications, the design of wearable antennas offers the possibility of ubiquitous monitoring, communication and energy harvesting and storage. Specific requirements for wearable antennas are a planar structure and flexible construction materials. Several properties of the materials influence the behaviour of the antenna. For instance, the bandwidth and the efficiency of a planar microstrip antenna are mainly determined by the permittivity and the thickness of the substrate. The use of textiles in wearable antennas requires the characterization of their properties. Specific electrical conductive textiles are available on the market and have been successfully used. Ordinary textile fabrics have been used as substrates. However, little information can be found on the electromagnetic properties of regular textiles. Therefore this paper is mainly focused on the analysis of the dielectric properties of normal fabrics. In general, textiles present a very low dielectric constant that reduces the surface wave losses and increases the impedance bandwidth of the antenna. However, textile materials are constantly exchanging water molecules with the surroundings, which affects their electromagnetic properties. In addition, textile fabrics are porous, anisotropic and compressible materials whose thickness and density might change with low pressures. Therefore it is important to know how these characteristics influence the behaviour of the antenna in order to minimize unwanted effects. This paper presents a survey of the key points for the design and development of textile antennas, from the choice of the textile materials to the framing of the antenna. An analysis of the textile materials that have been used is also presented. PMID:23202235

Salvado, Rita; Loss, Caroline; Gonçalves, Ricardo; Pinho, Pedro

2012-01-01

232

Textile materials for the design of wearable antennas: a survey.  

PubMed

In the broad context of Wireless Body Sensor Networks for healthcare and pervasive applications, the design of wearable antennas offers the possibility of ubiquitous monitoring, communication and energy harvesting and storage. Specific requirements for wearable antennas are a planar structure and flexible construction materials. Several properties of the materials influence the behaviour of the antenna. For instance, the bandwidth and the efficiency of a planar microstrip antenna are mainly determined by the permittivity and the thickness of the substrate. The use of textiles in wearable antennas requires the characterization of their properties. Specific electrical conductive textiles are available on the market and have been successfully used. Ordinary textile fabrics have been used as substrates. However, little information can be found on the electromagnetic properties of regular textiles. Therefore this paper is mainly focused on the analysis of the dielectric properties of normal fabrics. In general, textiles present a very low dielectric constant that reduces the surface wave losses and increases the impedance bandwidth of the antenna. However, textile materials are constantly exchanging water molecules with the surroundings, which affects their electromagnetic properties. In addition, textile fabrics are porous, anisotropic and compressible materials whose thickness and density might change with low pressures. Therefore it is important to know how these characteristics influence the behaviour of the antenna in order to minimize unwanted effects. This paper presents a survey of the key points for the design and development of textile antennas, from the choice of the textile materials to the framing of the antenna. An analysis of the textile materials that have been used is also presented. PMID:23202235

Salvado, Rita; Loss, Caroline; Gonçalves, Ricardo; Pinho, Pedro

2012-01-01

233

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

SciTech Connect

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.

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

2013-04-30

234

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

NASA Technical Reports Server (NTRS)

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.

1974-01-01

235

Interfacial properties and design of functional energy materials.  

PubMed

CONSPECTUS: The vital importance of energy to society continues to demand a relentless pursuit of energy responsive materials that can bridge fundamental chemical structures at the molecular level and achieve improved functionality and performance. This demand can potentially be realized by harnessing the power of self-assembly, a spontaneous process where molecules or much larger entities form ordered aggregates as a consequence of predominately noncovalent (weak) interactions. Self-assembly is the key to bottom-up design of molecular devices, because the nearly atomic-level control is very difficult to realize in a top-down, for example, lithographic, approach. However, while function in simple systems such as single crystals can often be evaluated a priori, predicting the function of the great variety of self-assembled molecular architectures is complicated by the lack of understanding and control over nanoscale interactions, mesoscale architectures, and macroscale order. To establish a foundation toward delivering practical solutions, it is critical to develop an understanding of the chemical and physical mechanisms responsible for the self-assembly of molecular and hybrid materials on various support substrates. Typical molecular self-assembly involves noncovalent intermolecular and substrate-molecule interactions. These interactions remain poorly understood, due to the combination of many-body interactions compounded by local or collective influences from the substrate atomic lattice and electronic structure. Progress toward unraveling the underlying physicochemical processes that control the structure and macroscopic physical, chemical, mechanical, electrical, and transport properties of materials increasingly requires tight integration of theory, modeling, and simulation with precision synthesis, advanced experimental characterization, and device measurements. Theory, modeling, and simulation can accelerate the process of materials understanding and design by providing atomic level understanding of the underlying physicochemical phenomena (illuminating connections between experiments). It can also provide the ability to explore new materials and conditions before they are realized in the laboratory. With tight integration and feedback with experiment, it becomes feasible to identify promising materials or processes for targeted energy applications. In this Account, we highlight recent advances and success in using an integrated approach based on electronic structure simulations and scanning probe microscopy techniques to study and design functional materials formed from the self-assembly of molecules into supramolecular or polymeric architectures on substrates. PMID:24963787

Sumpter, Bobby G; Liang, Liangbo; Nicolaï, Adrien; Meunier, Vincent

2014-11-18

236

TFTR materials issues and problems during design and construction  

NASA Astrophysics Data System (ADS)

TFTR as well as its contemporaries, T15, JT60 and JET, have important contributions to make towards our understanding of plasma conditions In the thermonuclear regime. One of the main objectives of TFTR is to produce fusion power densities approaching those in a fusion reactor, ˜1 Wcm -3, at Q ˜1 - 2. TFTR will be the first tokamak to routinely use deuterium tritium, and produce ˜10 19 fusion neutrons per pulse. With startup of TFTR on December 24, 1982, the demonstration of physics feasibility of "breakeven" is close at hand. Since TFTR performance will be reactor relevant, the capability of materials/components to withstand the hostile effects of a plasma environment will be presented. It is Intended that designers of future fusion devices benefit from the materials technology developments and applications on TFTR. In an attempt to comply with this mandate, this paper will describe TFTR issues on materials, their developments, selections, problems and solutions. Special emphasis will be given, in particular, to the impurity control devices in TFTR, namely, the limiter and surface pumping system located inside the vacuum vessel. The plasma will interact with these components and they will be subjected to disruptions, a vacuum of 10 -6 to 10 -8 torr and a nominal temperatures of <250°C. "Painful" materials development problems encountered will be reviewed, as well as important "lessons learned." A briefing on the materials of construction will be given, with some comments on the problems that developed and their solutions.

Sabado, M.; Little, R.

1984-05-01

237

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

SciTech Connect

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.

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

1998-11-01

238

Materials, design and processing of air encapsulated MEMS packaging  

NASA Astrophysics Data System (ADS)

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.

Fritz, Nathan T.

239

System design for safe robotic handling of nuclear materials  

SciTech Connect

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.

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

1996-03-01

240

A model for designing functionally gradient material joints  

SciTech Connect

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.

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

1994-12-31

241

Test model designs for advanced refractory ceramic materials  

NASA Technical Reports Server (NTRS)

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.

Tran, Huy Kim

1993-01-01

242

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

PubMed

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. PMID:24866174

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

2014-06-21

243

Variance calculations for materials accounting system design and evaluation  

SciTech Connect

Error propagation/variance calculations are used for establishing alarm limits for materials balance closures. Variance calculations may also be employed in the evaluation of accounting system designs for a proposed facility, as well as for upgrades of existing facilities. Information from such an exercise may be used to allocate resources for system improvements and identify process areas that require strict access or material controls. Simplifying assumptions are normally required since detailed data are not available for proposed facilities and may be difficult to obtain for existing facilities. Transfer, inventory, and measurement data are input into a code that calculates the variance for each term in the materials balance equation. Provision should be made for treatment of measurement correlations and holdup. The results are analyzed to determine major contributors to the total materials balance area (MBA) variance. A sensitivity analysis may be performed to determine the effect of changes in the measurements, measurement errors, or MBA structure. Examples of how variance calculations are used in accounting system analysis are discussed in the paper.

Thomas, K.E.

1987-01-01

244

Testing and design life analysis of polyurea liner materials  

NASA Astrophysics Data System (ADS)

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.

Ghasemi Motlagh, Siavash

245

Military turbojet component design and validation with thermostructural composite material  

SciTech Connect

Ceramic Matrix Composite (CMC) materials based on a concept providing both high temperature capabilities and high mechanical strength can meet new turbojet requirements. They have the potential to enhance performance and durability of pertinent parts. Lab characterization performed on test samples showed that SEPCARBINOX {reg_sign} C/SiC composites with adequate finishing treatments can sustain temperatures up to 600 - 650{degrees}C for long duration and CERASEP {reg_sign} SiC/SiC composites can sustain temperatures up to 1200{degrees}C. A large amount of R&D activities at SEP on CMC components over the last 10 years have demonstrated a good potential for C/SiC and SiC/SiC composites and brought design experience and methodology for developments. In the future, engines should be able to take advantage of an improved thermostructural material specifically developed for turbojet environment.

Spriet, P.; Boury, D.; Habarou, G. [SEP, Saint-Medard-en-Jalles (France)

1995-12-01

246

ATRP in the design of functional materials for biomedical applications  

PubMed Central

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

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

2013-01-01

247

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

Microsoft Academic Search

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

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

1988-01-01

248

Designing for Emotional Attachment to Energy Approaching energy as materiality Design exploration: Energy Mementos  

E-print Network

be with and through energy in everyday life. Designing for individuals to be emotionally connected to their energy one's self and community. James Pierce Eric Paulos Living Environments Lab Human-Computer Interaction Institute Carnegie Mellon University In order to begin to materially explore emotional attachment to energy

Paulos, Eric

249

From molecular design and materials construction to organic nanophotonic devices.  

PubMed

CONSPECTUS: Nanophotonics has recently received broad research interest, since it may provide an alternative opportunity to overcome the fundamental limitations in electronic circuits. Diverse optical materials down to the wavelength scale are required to develop nanophotonic devices, including functional components for light emission, transmission, and detection. During the past decade, the chemists have made their own contributions to this interdisciplinary field, especially from the controlled fabrication of nanophotonic molecules and materials. In this context, organic micro- or nanocrystals have been developed as a very promising kind of building block in the construction of novel units for integrated nanophotonics, mainly due to the great versatility in organic molecular structures and their flexibility for the subsequent processing. Following the pioneering works on organic nanolasers and optical waveguides, the organic nanophotonic materials and devices have attracted increasing interest and developed rapidly during the past few years. In this Account, we review our research on the photonic performance of molecular micro- or nanostructures and the latest breakthroughs toward organic nanophotonic devices. Overall, the versatile features of organic materials are highlighted, because they brings tunable optical properties based on molecular design, size-dependent light confinement in low-dimensional structures, and various device geometries for nanophotonic integration. The molecular diversity enables abundant optical transitions in conjugated ?-electron systems, and thus brings specific photonic functions into molecular aggregates. The morphology of these micro- or nanostructures can be further controlled based on the weak intermolecular interactions during molecular assembly process, making the aggregates show photon confinement or light guiding properties as nanophotonic materials. By adoption of some active processes in the composite of two or more materials, such as energy transfer, charge separation, and exciton-plasmon coupling, a series of novel nanophotonic devices could be achieved for light signal manipulation. First, we provide an overview of the research evolution of organic nanophotonics, which arises from attempts to explore the photonic potentials of low-dimensional structures assembled from organic molecules. Then, recent advances in this field are described from the viewpoints of molecules, materials, and devices. Many kinds of optofunctional molecules are designed and synthesized according to the demands in high luminescence yield, nonlinear optical response, and other optical properties. Due to the weak interactions between these molecules, numerous micro- or nanostructures could be prepared via self-assembly or vapor-deposition, bringing the capabilities of light transport and confinement at the wavelength scale. The above advantages provide great possibilities in the fabrication of organic nanophotonic devices, by rationally combining these functional components to manipulate light signals. Finally, we present our views on the current challenges as well as the future development of organic nanophotonic materials and devices. This Account gives a comprehensive understanding of organic nanophotonics, including the design and fabrication of organic micro- or nanocrystals with specific photonic properties and their promising applications in functional nanophotonic components and integrated circuits. PMID:25343682

Zhang, Chuang; Yan, Yongli; Zhao, Yong Sheng; Yao, Jiannian

2014-12-16

250

First-principles structural design of superhard materials  

NASA Astrophysics Data System (ADS)

We reported a developed methodology to design superhard materials for given chemical systems under external conditions (here, pressure). The new approach is based on the CALYPSO algorithm and requires only the chemical compositions to predict the hardness vs. energy map, from which the energetically preferable superhard structures are readily accessible. In contrast to the traditional ground state structure prediction method where the total energy was solely used as the fitness function, here we adopted hardness as the fitness function in combination with the first-principles calculation to construct the hardness vs. energy map by seeking a proper balance between hardness and energy for a better mechanical description of given chemical systems. To allow a universal calculation on the hardness for the predicted structure, we have improved the earlier hardness model based on bond strength by applying the Laplacian matrix to account for the highly anisotropic and molecular systems. We benchmarked our approach in typical superhard systems, such as elemental carbon, binary B-N, and ternary B-C-N compounds. Nearly all the experimentally known and most of the earlier theoretical superhard structures have been successfully reproduced. The results suggested that our approach is reliable and can be widely applied into design of new superhard materials.

Zhang, Xinxin; Wang, Yanchao; Lv, Jian; Zhu, Chunye; Li, Qian; Zhang, Miao; Li, Quan; Ma, Yanming

2013-03-01

251

Harvesting bioenergy with rationally designed complex functional materials  

NASA Astrophysics Data System (ADS)

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.

Kuang, Liangju

252

Micro-/nanostructured multicomponent molecular materials: design, assembly, and functionality.  

PubMed

Molecule-based micro-/nanomaterials have attracted considerable attention because their properties can vary greatly from the corresponding macro-sized bulk systems. Recently, the construction of multicomponent molecular solids based on crystal engineering principles has emerged as a promising alternative way to develop micro-/nanomaterials. Unlike single-component materials, the resulting multicomponent systems offer the advantages of tunable composition, and adjustable molecular arrangement, and intermolecular interactions within their solid states. The study of these materials also supplies insight into how the crystal structure, molecular components, and micro-/nanoscale effects can influence the performance of molecular materials. In this review, we describe recent advances and current directions in the assembly and applications of crystalline multicomponent micro-/nanostructures. Firstly, the design strategies for multicomponent systems based on molecular recognition and crystal engineering principles are introduced. Attention is then focused on the methods of fabrication of low-dimensional multicomponent micro-/nanostructures. Their new applications are also outlined. Finally, we briefly discuss perspectives for the further development of these molecular crystalline micro-/nanomaterials. PMID:25640467

Yan, Dongpeng

2015-03-23

253

Optimal Design of Honeycomb Material Used to Mitigate Head Impact  

PubMed Central

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

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

2013-01-01

254

Materials for Consideration in Standardized Canister Design Activities  

SciTech Connect

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 corrosionallowance 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 superduplex 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.

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

2014-10-01

255

Process design of press hardening with gradient material property influence  

SciTech Connect

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.

Neugebauer, R. [Fraunhofer Institute for Machine Tools and Forming Technology IWU, Chemnitz (Germany); Professorship for Machine Tools and Forming Technology, TU Chemnitz (Germany); Schieck, F. [Fraunhofer Institute for Machine Tools and Forming Technology IWU, Chemnitz (Germany); Rautenstrauch, A. [Professorship for Machine Tools and Forming Technology, TU Chemnitz (Germany)

2011-05-04

256

Process design of press hardening with gradient material property influence  

NASA Astrophysics Data System (ADS)

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.

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

2011-05-01

257

Interfacing materials science and biology for drug carrier design.  

PubMed

Over the last ten years, there has been considerable research interest in the development of polymeric carriers for biomedicine. Such delivery systems have the potential to significantly reduce side effects and increase the bioavailability of poorly soluble therapeutics. The design of carriers has relied on harnessing specific variations in biological conditions, such as pH or redox potential, and more recently, by incorporating specific peptide cleavage sites for enzymatic hydrolysis. Although much progress has been made in this field, the specificity of polymeric carriers is still limited when compared with their biological counterparts. To synthesize the next generation of carriers, it is important to consider the biological rationale for materials design. This requires a detailed understanding of the cellular microenvironments and how these can be harnessed for specific applications. In this review, several important physiological cues in the cellular microenvironments are outlined, with a focus on changes in pH, redox potential, and the types of enzymes present in specific regions. Furthermore, recent studies that use such biologically inspired triggers to design polymeric carriers are highlighted, focusing on applications in the field of therapeutic delivery. PMID:25728711

Such, Georgina K; Yan, Yan; Johnston, Angus P R; Gunawan, Sylvia T; Caruso, Frank

2015-04-01

258

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

E-print Network

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 ...

Gonzalez Uribe, Carlos David

2014-01-01

259

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...

260

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

E-print Network

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 ...

Eastman, Douglas Elmer

2004-01-01

261

Shape Design of Structures Using a BiMaterial With a StressRatio Redesign Algorithm  

E-print Network

The micromechanical approach to the shape design of structures consists in defining a domain of porous material the mechanical properties of a porous orthotropic material as a function of the density of material, and (cShape Design of Structures Using a Bi­Material Composite With a Stress­Ratio Redesign Algorithm

Fuchs, Moshe

262

Interfacial Properties and Design of Functional Energy Materials  

SciTech Connect

The vital importance of energy to society continues to demand a relentless pursuit of energy responsive materials that can bridge fundamental chemical structures at the molecular level and achieve improved functionality, such as efficient energy conversion/storage/transmission, over multiple length scales. This demand can potentially be realized by harnessing the power of self-assembly a spontaneous process where molecules or much larger entities form ordered aggregates as a consequence of predominately non-covalent (weak) interactions. Self-assembly is the key to bottom-up design of molecular devices, because the nearly atomic-level control is very difficult to realize in a top-down, e.g., lithographic approach. However, while function (e.g., charge mobility) in simple systems such as single crystals can often be predicted, predicting the function of the great variety of self-assembled molecular architectures is complicated by the lack of understanding and control over nanoscale interactions, mesoscale architectures, and macroscale (long-range) order. To establish a foundation toward delivering practical solutions, it is critical to develop an understanding of the chemical and physical mechanisms responsible for the self-assembly of molecular and hybrid materials on various substrates. Typically molecular self-assembly involves poorly understood non-covalent intermolecular and substrate-molecule interactions compounded by local and/or collective influences from the substrate atomic lattice (symmetry and/or topological features) and electronic structure. Thus, progress towards unraveling the underlying physicochemical processes that control the structure and macroscopic physical, mechanical, electrical, and transport properties of materials increasingly requires tight integration of theory, modeling and simulation with precision synthesis, advanced experimental characterization, and device measurements. In this mode, theory and simulation can greatly accelerate the process of materials discovery by providing atomic level understanding of physicochemical phenomena and for making predictions of trends. In particular, this approach can provide understanding, prediction and exploration of new materials and conditions before they are realized in the lab, to illuminate connections between experimental observations, and help identify new materials for targeted synthesis. Toward this end, Density Functional Theory (DFT) can provide a suitable computational framework for investigating the inter- and intramolecular bonding, molecular conformation, charge and spin configurations that are intrinsic to self-assembly of molecules on substrates. This Account highlights recent advances in using an integrated approach based on DFT and scanning probe microscopy [STM(s), AFM] to study/develop electronic materials formed from the self-assembly of molecules into supramolecular or polymeric architectures on substrates. Here it is the interplay between molecular interactions and surface electrons that is used to control the final architecture and subsequent bulk properties of the two-dimensional patterns/assemblies. Indeed a rich variety of functional energy materials become possible.

Sumpter, Bobby G [ORNL] [ORNL; Liang, Liangbo [ORNL] [ORNL; Nicolai, Adrien [Rensselaer Polytechnic Institute (RPI)] [Rensselaer Polytechnic Institute (RPI); Meunier, V. [Rensselaer Polytechnic Institute (RPI)] [Rensselaer Polytechnic Institute (RPI)

2014-01-01

263

Materials Design based on Predictive Ab Initio Thermodynamics  

NASA Astrophysics Data System (ADS)

A key requirement in developing predictive multi-scale modeling is the availability of accurate computational tools determining energies not only at T = 0 K but also under realistic conditions, i.e., at finite temperature. Combining accurate first principles calculations with mesoscopic/macroscopic thermodynamic and/or kinetic concepts allows now to address this issue and to determine free energies and derived thermodynamic quantities such as heat capacity, thermal expansion coefficients, and elastic constants with an accuracy that matches and often even rivals available experimental data. In the talk a brief overview of the fundamentals and recent developments of combining modern fully parameter-free ab initio methods with thermodynamic concepts will be given with special emphasize on structural materials. The flexibility and the predictive power of these approaches and the impact they can have in developing new strategies in materials design will be discussed e.g. for modern high strength TWIP/TRIP steels, for understanding failure mechanisms such as hydrogen embrittlement, or for identifying chemical trends in the performance of light weight metallic alloys. Work has been done in collaboration with Fritz Kormann, Blazej Grabowski, and Tilmann Hickel.

Neugebauer, Joerg

2013-03-01

264

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

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

265

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

SciTech Connect

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.

NONE

1995-07-14

266

Multiscale materials design of natural exoskeletons : fish armor  

E-print Network

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, ...

Song, Juha

2011-01-01

267

Study of left-handed materials  

Microsoft Academic Search

Left handed materials (LHMs) are artificial materials that have negative electrical permittivity, negative magnetic permeability, and negative index of refraction across a common frequency band. They possess electromagnetic (EM) properties not found in nature. LHMs have attracted tremendous attention because of their potential applications to build the perfect lens and cloaking devices. In the past few years there has been

Jiangfeng Zhou

2008-01-01

268

Guiding the design and application of new materials for enhancing sustainability performance: Framework and infrastructure application  

Microsoft Academic Search

This paper presents a framework for guiding the design of new materials to enhance the sustainability of systems that utilize these materials throughout their production, use and retirement. Traditionally, materials engineering has focused on the interplay between material microstructure, physical properties, processing, and performance. Environmental impacts related to the system's life cycle are not well integrated into the materials engineering

Gregory A. Keoleian; Alissa M. Kendall; Michael D. Lepech; Victor C. Li

2006-01-01

269

Design and development of advanced castable refractory materials  

NASA Astrophysics Data System (ADS)

New formulations of castable refractory composite materials were studied. This technology is used to produce low cost composite concrete structures designed for high temperature stability, superior wear resistance and improved strength. An in situ fired, castable cement installation is a heterogeneous structure divided into three zones according to the temperature history and microstructure. The properties of each zone depend on the predominant bonding mode between constituents. Each zone has a characteristic microstructure that influences the integrity of the monolith. The hot side may have a highly dense and developed network of ceramic bonds between constituent particles while the cold side may never reach temperatures sufficient to drive off free water. The thermal, structural and tribological properties depend on the microstructure and the type of bonding that holds the monolith together. The phase distributions are defined by sets of metastable phase conditions driven by the local hydrated chemistry, nearest neighbor oxide compounds, impurities and sintering temperature. Equilibrium phase diagrams were used to select optimum compositions based on higher melting point phases. The phase diagrams were also used to target high temperature phase fields that are stable over wide temperature and stoichiometric ranges. Materials selection of candidate hydraulic clinkers, high temperature oxides, and reinforcement phases were based on requirements for high temperature stability. The calcium aluminate (CaO-Al2O3) and calcium dialuminate (CaO-(Al2O3)2) are common refractory clinkers used in castable refractory cements. The thermodynamics and kinetics of cement hydrate formation are well studied and suited to become the building block of a design for a superior refractory castable cement. The inert oxides mixed with the calcium aluminate clinkers are magnesia (MgO), alumina (Al 2O3), spinel (MgAl2O4) and chromic (Cr2O3). The bulk of the experiments concentrated in the Al2O3--MgO--CaO ternary system. Materials selection criteria for reinforcement materials was based on improved high temperature stability, increased strength, reduced thermal expansion mismatch, low thermal conductivity and increasing wear resistance. The reinforcement phases selected for this investigation are zircon (ZrSiO4), zirconia (ZrO2), spinel (MgAl2O4) and dead burnt magnesia (MgO). Batches of the formulations were tested for thermal conductivity, wear resistance and mechanical strength. Relative rankings of the formulations against commercial products indicate improved or similar performance with increased maximum temperature limits and improved thermal insulating power. The new cement formulations proved to exhibit superior high temperature stability with an increasing volume fraction of high temperature oxides. The addition of reinforcement aggregates and powder sizing to offset the loss of strength. The room temperature compression strength and wear resistance of the optimized formulations exceeded the properties of conventional refractory, brick and castable cement tested concurrently.

Davis, Robert Bruce

270

Design of digital learning material for bioprocess-engineering-education  

Microsoft Academic Search

With the advance of computers and the internet, new types of learning material can be developed: web-based digital learning material. Because many complex learning objectives in the food- and bioprocess technology domain are difficult to achieve in a traditional learning environment, a project was started to explore the possibilities of digital learning material to address those learning objectives. The material

Schaaf van der H

2007-01-01

271

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

PubMed

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

Cherukuvada, Suryanarayan; Nangia, Ashwini

2014-01-28

272

Dynamic Contact Performance of Rubber Materials for Designing Wiper Blades  

NASA Astrophysics Data System (ADS)

A printer assembly consisting of a pen, wiper with two blades, and wiper blade holder is investigated in this study. The two wiper blades press onto the pen surface via proper dimension interference, while wiping across the pen at a certain speed. A finite element model (FEM) was set up with ANSYS-LSDYNA. The hyper-elastic rubber wiper blades are described by Christensen’s model with n = 1 for the strain energy density function. Dynamic contact forces between the wiper blades and the pen, number of contacts, and the duration of the wiper blades jumping over the pen are numerically simulated. Effects of the mechanical properties of the rubber materials, i.e., the coefficient of the Christensen’s model, C 10, on the dynamic contact performance are investigated. The wiper blades are found to periodically touch and jump off from the pen. For the contact between the front blade and the pen, results show that the average contact forces and the number of the contact will increase with C 10, and for the back wiper blade there exist the same conclusions, except that the jumping duration of the back wiper blade does not decrease steadily, but shows a minimum. These results suggest that a new design with two curved sides of the blade tip could be beneficence.

Jiang, Dazhi; Shu, Dongwei

2009-04-01

273

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

SciTech Connect

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.

Hilton, Harry H. [Aerospace Engineering Department, Technology Research, Education and Commercialization Center, National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign, 104 South Wright Street, MC-236 Urbana, IL 61801-2935 (United States)

2008-02-15

274

Materials selection in micromechanical design: an application of the Ashby approach  

Microsoft Academic Search

The set of materials available to microsystems designers is rapidly expanding. Techniques now exist to introduce and integrate a large number of metals, alloys, ceramics, glasses, polymers, and elastomers into microsystems, motivating the need for a rational approach for materials selection in microsystems design. As a step toward such an approach, we focus on the initial stages of materials selection

V. T. Srikar; S. Mark Spearing

2003-01-01

275

Design of materials with extreme thermal expansion using a three-phase topology optimization method  

Microsoft Academic Search

We show how composites with extremal or unusual thermal expansion coefficients can be designed using a numerical topology optimization method. The composites are composed of two different material phases and void. The optimization method is illustrated by designing materials having maximum thermal expansion, zero thermal expansion, and negative thermal expansion. Assuming linear elasticity, it is shown that materials with effective

Ole Sigmund; Salvatore Torquato

1997-01-01

276

Simulation and design optimization of wave propagation in heterogeneous materials  

E-print Network

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 ...

Saà-Seoane, Joel

2014-01-01

277

Fab trees for designing complex 3D printable materials  

E-print Network

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 ...

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

2013-01-01

278

Function Materialization in Object Bases: Design, Realization, and Evaluation  

Microsoft Academic Search

View materialization is a well-known optimization technique of relational database systems. We present a similar, yet more powerful, optimization concept for object-oriented data models: function materialization. Exploiting the object-oriented paradigm-namely, classification, object identity, and encapsulation-facilitates a rather easy incorporation of function materialization into (existing) object-oriented systems. Only those types (classes) whose instances are involved in some materialization are appropriately modified

Alfons Kemper; Christoph Kilger; Guido Moerkotte

1994-01-01

279

Hyperform specification: designing and interacting with self-reconfiguring materials  

Microsoft Academic Search

We are on the verge of realizing a new class of material that need not be machined or molded in order to make things. Rather,\\u000a the material forms and re-forms itself according to software programmed into its component elements. These self-reconfiguring materials are composed of robotic modules that coordinate with each other locally to produce global behaviors. These robotic materials

Michael Philetus Weller; Mark D. Gross; Seth Copen Goldstein

2011-01-01

280

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

ERIC Educational Resources Information Center

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…

Potter, Patricia

2013-01-01

281

Computer-aided blanking sequence design of extruded aluminum materials  

Microsoft Academic Search

Extruded aluminum alloys are presently used for building materials. We developed an expert system for blanking process planning for these three-dimensional materials using feature elimination. We consider that blanking adds features to a raw material and process planning eliminates features from a product. We attempted to implement a feature elimination procedure on computers. The shape model of the product consists

Takahiro Ohashi; Yoshinobu Saeki; Mitsugu Motomura; Yoshinari Oki

2002-01-01

282

Design and material selection for inverter transformer cores  

NASA Technical Reports Server (NTRS)

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.

Mclyman, W. T.

1973-01-01

283

A demonstration of simple airfoils: Structural design and materials choices  

SciTech Connect

An educational unit is presented for building and evaluating simple wing structures, in order to learn about materials choice and lightweight construction. This unit is appropriate for a high school materials science class or lower-division college courses in structural engineering, materials science, or aeronautical engineering.

Bunnell, L.R. [Pacific Northwest Lab., Richland, WA (United States); Piippo, S.W. [Richland School District, WA (United States)

1993-01-01

284

Designing metallic materials from abundant resources for more efficient utilization  

Microsoft Academic Search

Metallic materials are a good example of what might be termed a demand driven technology. Less frequently, materials with unusual properties provide an opportunity for new applications, e.g., an opportunity seeking technology. High performance fiber composites are the most recent example. The recent threats of materials shortages, particularly chromium, nickel and cobalt, have prompted consideration of substitutions and alloys based

Robert I. Jaffee

1976-01-01

285

A knowledge-based system for materials selection in mechanical engineering design  

Microsoft Academic Search

This paper studies various work on the development of computerized material selection system. The importance of knowledge-based system (KBS) in the context of concurrent engineering is explained. The study of KBS in material selection in an engineering design process is described. The development in materials databases, which sometimes serve as material selection packages, is also discussed. The use of KBS

S. M Sapuan

2001-01-01

286

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

E-print Network

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 ...

Giesa, Tristan

287

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

Code of Federal Regulations, 2011 CFR

...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....

2011-10-01

288

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

Code of Federal Regulations, 2010 CFR

...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....

2010-10-01

289

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

Code of Federal Regulations, 2013 CFR

...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....

2013-10-01

290

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

Code of Federal Regulations, 2012 CFR

...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....

2012-10-01

291

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

Code of Federal Regulations, 2014 CFR

...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....

2014-10-01

292

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

NSDL National Science Digital Library

Nutritional genomics, or nutrigenomics, can be considered as the combination of molecular nutrition and genomics. This study describes digital nutrigenomics learning material suitable for students from various backgrounds and provides design guidelines for the development of the learning material.

Maria C. Busstra (Wageningen University Nutrition, Metabolism, and Genomics Group, Division of Human Nutrition)

2007-03-01

293

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

E-print Network

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 ...

Sudajit-apa, Melada

2008-01-01

294

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

NASA Astrophysics Data System (ADS)

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.

Czech, Christopher

295

Materials and Design 23 (2002) 657666 0261-3069/02/$ -see front matter 2002 Elsevier Science Ltd. All rights reserved.  

E-print Network

of functionally gradient materials (FGM) is presented. Different microstructures formed by two primary materials material distribution function is used. The bi-objective FGM optimization design procedure is highlighted material (FGM); Micromechanical analysis; Effective material properties; Numerical analysis; Bi

Grujicic, Mica

296

Computational design of deformation processes for materials with ductile damage  

E-print Network

-plasticity; Thermomechanical analysis; Ductile damage; Optimization; Computational design 1. Introduction Most macroscopic. The accuracy and effectiveness of the developed updated Lagrangian finite element analysis and design. Keywords: Continuum sensitivity analysis; Lagrangian analysis; Metal forming; Elasto

Zabaras, Nicholas J.

297

Role of dislocation theory in the design of engineering materials  

SciTech Connect

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.

Morris, J.W. Jr.

1980-06-01

298

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

Code of Federal Regulations, 2013 CFR

...Property AMERICAN BATTLE MONUMENTS COMMISSION MONUMENTS AND MEMORIALS § 401.5 Control and supervision of materials, design...the design and prescribes regulations for the building of all memorial monuments and buildings commemorating the service of...

2013-07-01

299

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

Code of Federal Regulations, 2012 CFR

...Property AMERICAN BATTLE MONUMENTS COMMISSION MONUMENTS AND MEMORIALS § 401.5 Control and supervision of materials, design...the design and prescribes regulations for the building of all memorial monuments and buildings commemorating the service of...

2012-07-01

300

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

Code of Federal Regulations, 2010 CFR

...Property AMERICAN BATTLE MONUMENTS COMMISSION MONUMENTS AND MEMORIALS § 401.5 Control and supervision of materials, design...the design and prescribes regulations for the building of all memorial monuments and buildings commemorating the service of...

2010-07-01

301

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

Code of Federal Regulations, 2014 CFR

...Property AMERICAN BATTLE MONUMENTS COMMISSION MONUMENTS AND MEMORIALS § 401.5 Control and supervision of materials, design...the design and prescribes regulations for the building of all memorial monuments and buildings commemorating the service of...

2014-07-01

302

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

Code of Federal Regulations, 2011 CFR

...Property AMERICAN BATTLE MONUMENTS COMMISSION MONUMENTS AND MEMORIALS § 401.5 Control and supervision of materials, design...the design and prescribes regulations for the building of all memorial monuments and buildings commemorating the service of...

2011-07-01

303

Optimal shape design as a material distribution problem  

Microsoft Academic Search

Shape optimization in a general setting requires the determination of the optimal spatial material distribution for given loads and boundary conditions. Every point in space is thus a material point or a void and the optimization problem is a discrete variable one. This paper describes various ways of removing this discrete nature of the problem by the introduction of a

M. P. Bendsøe

1989-01-01

304

The Design of Reactions, Catalysts and Materials with Aromatic Ions  

NASA Astrophysics Data System (ADS)

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.

Bandar, Jeffrey Scott

305

Computational Design of Novel, Radiation Resistant Fusion Materials  

SciTech Connect

The promise of fusion as a viable 21st century energy source requires the development of advanced structural (MFE and IFE) and optical (IFE) materials that are capable of withstanding the harsh radiation environment that leads to the degradation of physical and mechanical properties. Materials in fusion environments must be able to handle 14 MeV neutrons produced from Deuterium-Tritium nuclear reactions, as well as the insoluble He and reactive H gases that lead to swelling and embrittlement. Additionally, with the requirement of very high thermal loads makes the development of new advanced materials a formidable challenge. The scope of this study was to determine the feasibility of using atomistic simulations to predict the radiation response of novel materials engineered with potentially self-healing properties to survive in radiation environments over very long time-scales. The class of materials that shows promise is what is called a nanocrystalline material. Nanocrystalline materials are defined as those having very fine grains on the order of several to tens of nanometers in size, and consequently very high grain-boundary to volume ratio. Experimental observations [1] suggests that these grain-boundary networks can act as sinks for defects and hence promote self-repair.

Kubota, A; Caturla, M J; Wirth, B D; Latkowski, J

2003-02-01

306

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

NASA Technical Reports Server (NTRS)

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.

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

1988-01-01

307

Design of novel lithium storage materials with a polyanionic framework  

E-print Network

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 ...

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

2014-01-01

308

Materials by design—A perspective from atoms to structures  

E-print Network

Biological materials are effectively synthesized, controlled, and used for a variety of purposes in Nature—in spite of limitations in energy, quality, and quantity of their building blocks. Whereas the chemical composition ...

Buehler, Markus J.

309

Racial Implications for the Design of Instructional Materials  

ERIC Educational Resources Information Center

The results of this research indicated that black and white voices used in instructional materials are accepted by both white and black pupils, however white pupils rated visuals representing only black people lower than visuals representing only white people. (RC)

Hull, Gary L.

1975-01-01

310

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

E-print Network

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...

Park, Jinhee

2013-04-19

311

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. ...

312

Bioreceptivity evaluation of cementitious materials designed to stimulate biological growth.  

PubMed

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

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

2014-05-15

313

Advanced computational research in materials processing for design and manufacturing  

SciTech Connect

Advanced mathematical techniques and computer simulation play a major role in providing enhanced understanding of conventional and advanced materials processing operations. Development and application of mathematical models and computer simulation techniques can provide a quantitative understanding of materials processes and will minimize the need for expensive and time consuming trial- and error-based product development. As computer simulations and materials databases grow in complexity, high performance computing and simulation are expected to play a key role in supporting the improvements required in advanced material syntheses and processing by lessening the dependence on expensive prototyping and re-tooling. Many of these numerical models are highly compute-intensive. It is not unusual for an analysis to require several hours of computational time on current supercomputers despite the simplicity of the models being studied. For example, to accurately simulate the heat transfer in a 1-m{sup 3} block using a simple computational method requires 10`2 arithmetic operations per second of simulated time. For a computer to do the simulation in real time would require a sustained computation rate 1000 times faster than that achievable by current supercomputers. Massively parallel computer systems, which combine several thousand processors able to operate concurrently on a problem are expected to provide orders of magnitude increase in performance. This paper briefly describes advanced computational research in materials processing at ORNL. Continued development of computational techniques and algorithms utilizing the massively parallel computers will allow the simulation of conventional and advanced materials processes in sufficient generality.

Zacharia, T.

1995-04-01

314

Designing Web-Based Educative Curriculum Materials for the Social Studies  

ERIC Educational Resources Information Center

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…

Callahan, Cory; Saye, John; Brush, Thomas

2013-01-01

315

Advanced computational research in materials processing for design and manufacturing  

SciTech Connect

The computational requirements for design and manufacture of automotive components have seen dramatic increases for producing automobiles with three times the mileage. Automotive component design systems are becoming increasingly reliant on structural analysis requiring both overall larger analysis and more complex analyses, more three-dimensional analyses, larger model sizes, and routine consideration of transient and non-linear effects. Such analyses must be performed rapidly to minimize delays in the design and development process, which drives the need for parallel computing. This paper briefly describes advanced computational research in superplastic forming and automotive crash worthiness.

Zacharia, T. [Oak Ridge National Lab., TN (United States). Metals and Ceramics

1994-12-31

316

Materials technology assessment for a 1050 K Stirling space engine design  

NASA Technical Reports Server (NTRS)

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.

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

317

Materials technology assessment for a 1050 K Stirling Space Engine design  

SciTech Connect

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.

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

318

Lakes, R. S., "Design considerations for negative Poisson's ratio materials"ASME Journal of Mechanical Design, 115, 696-700,  

E-print Network

1 Lakes, R. S., "Design considerations for negative Poisson's ratio materials"ASME Journal and a flexible impact buffer. 1 Introduction Recently, the invention of negative Poisson's ratio foams was reported[1-3]. Foam materials based on metals and several polymers were transformed so that their cellular

Lakes, Roderic

319

New Materials Design Through Friction Stir Processing Techniques  

NASA Astrophysics Data System (ADS)

Friction Stir Welding (FSW) has reached a large interest in the scientific community and in the last years also in the industrial environment, due to the advantages of such solid state welding process with respect to the classic ones. The complex material flow occurring during the process plays a fundamental role in such solid state welding process, since it determines dramatic changes in the material microstructure of the so called weld nugget, which affects the effectiveness of the joints. What is more, Friction Stir Processing (FSP) is mainly being considered for producing high-strain-rate-superplastic (HSRS) microstructure in commercial aluminum alloys. The aim of the present research is the development of a locally composite material through the Friction Stir Processing (FSP) of two AA7075-T6 blanks and a different material insert. The results of a preliminary experimental campaign, carried out at the varying of the additional material placed at the sheets interface under different conditions, are presented. Micro and macro observation of the such obtained joints permitted to investigate the effects of such process on the overall joint performance.

Buffa, G.; Fratini, L.; Shivpuri, R.

2007-04-01

320

Catalytic converter design and materials. (Bibliography from the Global Mobility database). Published Search  

SciTech Connect

The bibliography contains citations concerning the various designs, configurations, and materials used in catalytic converters to diminish emissions from automotive, truck, diesel, and off-highway vehicles. Citations examine designs using internal flows and diffuser-monolith flows; the effects of flow maldistribution and steady state heat transfer; and materials, including platinum-palladium, urea-SCR, and copper-zeolite. Light-off and three-way catalysts and those designed for natural gas are emphasized. References also cite air/fuel tests, Taguchi techniques, and European and American standards affecting design and materials. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

NONE

1997-06-01

321

Catalytic converter design and materials. (A bibliography from the Global Mobility database). Published Search  

SciTech Connect

The bibliography contains citations concerning the various designs, configurations, and materials used in catalytic converters to diminish emissions from automotive, truck, diesel, and off-highway vehicles. Citations examine designs using internal flows and diffuser-monolith flows; the effects of flow maldistribution and steady state heat transfer; and materials, including platinum-palladium, urea-SCR, and copper-zeolite. Light-off and three-way catalysts and those designed for natural gas are emphasized. References also cite air/fuel tests, Taguchi techniques, and European and American standards affecting design and materials. (Contains a minimum of 220 citations and includes a subject term index and title list.)

Not Available

1993-12-01

322

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 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...

2010-10-01

323

A co-designed hardware/software architecture for augmented materials  

E-print Network

A co-designed hardware/software architecture for augmented materials Simon Dobson1 , Kieran Delaney, Dublin IE sergey.tsvetkov@cs.tcd.ie Abstract. Recent advances in materials, sensing, power harvesting, context- awareness and miniaturisation have opened-up the possibility of con- structing materials

Dobson, Simon

324

Design of multiphysics actuators using topology optimization – Part II: Two-material structures  

Microsoft Academic Search

This is the second part of a two-paper description of the topology optimization method applied to the design of multiphysics actuators and electrothermomechanical systems in particular. The first paper is focussed on one-material structures, the second on two-material structures. The extensions of the topology optimization method in this part include design descriptions for two-material structures, constitutive modelling of elements with

O. Sigmund

2001-01-01

325

Materials design and processings for industrial high-strain-rate superplastic forming  

SciTech Connect

The optimum materials design in microstructural control could be developed for the high-strain-rate superplastic materials in the industrial scale. In the present work, it is reported that the high-performance-engine pistons with near-net-shape can be fabricated by the superplastic forging technology in the high-strain-rate superplastic PM Al-Si based alloy, which is produced by using this optimum materials design.

Hosokawa, H.; Higashi, K.

2000-07-01

326

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...

327

Photovoltaic module encapsulation design and materials section, volume 2  

NASA Technical Reports Server (NTRS)

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.

Cuddihy, E. F.

1984-01-01

328

Designing materials for plasmonic systems: the alkali-noble intermetallics.  

PubMed

We use electronic structure calculations based upon density functional theory to search for ideal plasmonic materials among the alkali-noble intermetallics. Importantly, we use density functional perturbation theory to calculate the electron-phonon interaction and from there use a first order solution to the Boltzmann equation to estimate the phenomenological damping frequency in the Drude dielectric function. We discuss the necessary electronic features of a plasmonic material and investigate the optical properties of the alkali-noble intermetallics in terms of some generic plasmonic system quality factors. We conclude that at low negative permittivities, KAu, with a damping frequency of 0.0224 eV and a high optical gap to bare plasma frequency ratio, outperforms gold and to some extent silver as a plasmonic material. Unfortunately, a low plasma frequency (1.54 eV) reduces its utility in modern plasmonics applications. We also discuss, briefly, the effect of local fields on the optical properties of these materials. PMID:21389416

Blaber, M G; Arnold, M D; Ford, M J

2010-03-10

329

Design and Processing in the Materials Science and Engineering Curriculum  

Microsoft Academic Search

The curriculum in Materials Science and Engineering (MSE) is extremely broad, as the field encompasses a very large range of both scientific and engineering concepts. The undergraduate curriculum emphasizes the scientific fundamentals underlying the field, as is true of most university courses. However, both students and faculty in the MIT MSE department have felt recently that the curriculum may have

David Roylance

330

Designed amyloid fibers as materials for selective carbon dioxide capture  

E-print Network

materials capable of binding carbon dioxide are essential for addressing climate change. Here, we agent of climate change (1, 2). The major sources of anthropogenic carbon dioxide are the flue gas of power plants and automobile emissions. The dominant method for capture is passing postcombustion flue

331

New Materials Design Through Friction Stir Processing Techniques  

Microsoft Academic Search

Friction Stir Welding (FSW) has reached a large interest in the scientific community and in the last years also in the industrial environment, due to the advantages of such solid state welding process with respect to the classic ones. The complex material flow occurring during the process plays a fundamental role in such solid state welding process, since it determines

G. Buffa; L. Fratini; R. Shivpuri

2007-01-01

332

The Empirical Attitude, Material Practice and Design Activities  

ERIC Educational Resources Information Center

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…

Apedoe, Xornam; Ford, Michael

2010-01-01

333

Microstructural design of composite materials for crashworthy structural applications  

Microsoft Academic Search

Traditionally, metals are used for crashworthy structural applications, mainly due to their plastic deformation characteristics that enable them to absorb impact energy in a controlled manner. Unlike the metals, polymer composite materials display little plastic deformation characteristics. The use of polymer composites for crashworthy structural applications is a major challenge for the composite community. Current research work clearly suggests that

S Ramakrishna

1997-01-01

334

Designing nacre-like materials for simultaneous stiffness, strength and toughness: Optimum materials, composition, microstructure and size  

NASA Astrophysics Data System (ADS)

Nacre, bone and spider silk are staggered composites where inclusions of high aspect ratio reinforce a softer matrix. Such staggered composites have emerged through natural selection as the best configuration to produce stiffness, strength and toughness simultaneously. As a result, these remarkable materials are increasingly serving as model for synthetic composites with unusual and attractive performance. While several models have been developed to predict basic properties for biological and bio-inspired staggered composites, the designer is still left to struggle with finding optimum parameters. Unresolved issues include choosing optimum properties for inclusions and matrix, and resolving the contradictory effects of certain design variables. Here we overcome these difficulties with a multi-objective optimization for simultaneous high stiffness, strength and energy absorption in staggered composites. Our optimization scheme includes material properties for inclusions and matrix as design variables. This process reveals new guidelines, for example the staggered microstructure is only advantageous if the tablets are at least five times stronger than the interfaces, and only if high volume concentrations of tablets are used. We finally compile the results into a step-by-step optimization procedure which can be applied for the design of any type of high-performance staggered composite and at any length scale. The procedure produces optimum designs which are consistent with the materials and microstructure of natural nacre, confirming that this natural material is indeed optimized for mechanical performance.

Barthelat, Francois

2014-12-01

335

Design of a scientific probe for obtaining Mars surface material  

NASA Technical Reports Server (NTRS)

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.

1990-01-01

336

Designing for time-dependent material response in spacecraft structures  

NASA Technical Reports Server (NTRS)

To study the influence on overall deformations of the time-dependent constitutive properties of fiber-reinforced polymeric matrix composite materials being considered for use in orbiting precision segmented reflectors, simple sandwich beam models are developed. The beam models include layers representing the face sheets, the core, and the adhesive bonding of the face sheets to the core. A three-layer model lumps the adhesive layers with the face sheets or core, while a five-layer model considers the adhesive layers explicitly. The deformation response of the three-layer and five-layer sandwich beam models to a midspan point load is studied. This elementary loading leads to a simple analysis, and it is easy to create this loading in the laboratory. Using the correspondence principle of viscoelasticity, the models representing the elastic behavior of the two beams are transformed into time-dependent models. Representative cases of time-dependent material behavior for the facesheet material, the core material, and the adhesive are used to evaluate the influence of these constituents being time-dependent on the deformations of the beam. As an example of the results presented, if it assumed that, as a worst case, the polymer-dominated shear properties of the core behave as a Maxwell fluid such that under constant shear stress the shear strain increases by a factor of 10 in 20 years, then it is shown that the beam deflection increases by a factor of 1.4 during that time. In addition to quantitative conclusions, several assumptions are discussed which simplify the analyses for use with more complicated material models. Finally, it is shown that the simpler three-layer model suffices in many situations.

Hyer, M. W.; Oleksuk, Lynda L. S.; Bowles, D. E.

1992-01-01

337

Structural design methodologies for ceramic-based material systems  

NASA Technical Reports Server (NTRS)

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.

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

1991-01-01

338

Nonstoichiometric Laser Materials: Designer Wavelengths in Neodymium Doped Garnets  

NASA Technical Reports Server (NTRS)

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.

Walsh, Brian M.; Barnes, Norman P.

2008-01-01

339

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

SciTech Connect

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.

Horvath, J.A.; Pratuch, S.M.; Belser, F.C. [Lawrence Livermore National Lab., CA (United States)

1993-09-16

340

Biochemically designed polymers as self-organized materials  

NASA Astrophysics Data System (ADS)

Self assembled molecular systems are a focus of attention for material scientists as they provide an inherent molecular level organization responsible for enhanced material properties. We have developed polymeric molecular systems with interesting optical properties by biochemical engineering, which can be self assembled to thin films. Horseradish peroxidase catalyzed polymerizations of phenolic monomers: 9-hydroxyquinoline-5-sulfonic acid, acid red and decyl ester (d&l isomers) of tyrosine, have been achieved in the presence of hydrogen peroxide. The polymer of 8- hydroxyquinoline-5-sulfonic acid acts as a polymeric ligand that can be used for metal ion sensing. The polymer of acid red, with azo functional groups in the polymer backbone, shows interesting optical properties. Amphiphilic derivatives of tyrosine self assemble into tubules from micelles in aqueous solutions. These tubules have been enzymatically polymerized to polymeric tubules. The tubules are of 5 micrometers average diameter and > 200 micrometers length. The formation and properties of these tubules are discussed.

Alva, Shridhara; Sarma, Rupmoni; Marx, Kenneth A.; Kumar, Jayant; Tripathy, Sukant K.; Akkara, Joseph A.; Kaplan, David L.

1997-02-01

341

Packaging Materials and Design for Improved PV Module Reliability  

SciTech Connect

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.

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

2005-01-01

342

Recent progress in supercapacitors: from materials design to system construction.  

PubMed

Supercapacitors are currently attracting intensive attention because they can provide energy density by orders of magnitude higher than dielectric capacitors, greater power density, and longer cycling ability than batteries. The main challenge for supercapacitors is to develop them with high energy density that is close to that of a current rechargeable battery, while maintaining their inherent characteristics of high power and long cycling life. Consequently, much research has been devoted to enhance the performance of supercapacitors by either maximizing the specific capacitance and/or increasing the cell voltage. The latest advances in the exploration and development of new supercapacitor systems and related electrode materials are highlighted. Also, the prospects and challenges in practical application are analyzed, aiming to give deep insights into the material science and electrochemical fields. PMID:24089352

Wang, Yonggang; Xia, Yongyao

2013-10-01

343

Design and Application of Materials in Science and  

E-print Network

software: model design, meshing, solving and analysis of results. 8-12 13 Applications of finite element and plane strain elasticity, beam theory, axisymmetric and Cartesian coordinates. 7 7 Finite element): principles and governing equations, discretisation techniques, finite difference (FD) and finite volume (FV

New South Wales, University of

344

Design of a scientific probe for obtaining Mars surface material  

NASA Technical Reports Server (NTRS)

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.

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

1990-01-01

345

Material Surface Design to Counter Electromagnetic Interrogation of Targets  

E-print Network

composite layers of ferromagnetic and electronic devices and used to demonstrate feasibility of con- trol. The technical ideas developed here also have potential to aid in the design of medical shields employed to protect parts of an irradiated target or to focus radiation to pinpoint specific regions of the target

346

MaterialsProcessDesign and ControlLaboratory Cornell University  

E-print Network

-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 disk Superalloy microstructure Sheared ' precipitates Pairs of edge dislocations interacting

Zabaras, Nicholas J.

347

Evolutionary Design of a Robotic Material Defect Detection System  

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

348

Laboratory experiments designed to test the remediation properties of materials  

SciTech Connect

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).

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

1999-07-01

349

Self-expanding nitinol stents: material and design considerations  

Microsoft Academic Search

Nitinol (nickel–titanium) alloys exhibit a combination of properties which make these alloys particularly suited for self-expanding stents. Some of these properties cannot be found in engineering materials used for stents presently. This article explains the fundamental mechanism of shape memory and superelasticity, and how they relate to the characteristic performance of self-expanding stents. Nitinol stents are manufactured to a size

Dieter Stoeckel; Alan Pelton; Tom Duerig

2004-01-01

350

SRM nozzle design breakthroughs with advanced composite materials  

NASA Astrophysics Data System (ADS)

The weight reduction-related performance and cost of the Space Shuttle's Solid Rocket Motor (SRM) units' critical nozzle components are undergoing revolutionary improvements through the use of 3D-woven carbon/carbon and carbon/alumina composite materials. These can be used to fabricate the SRM's nozzle throat nondegradable insulators, thermostructural insulator, and exit cones. Additional developments are noted among nozzle-related structural components for additional rocket propulsion systems, including a three-piece extendible nozzle.

Berdoyes, Michel

1993-06-01

351

First Materials Science Research Facility Rack Capabilities and Design Features  

NASA Astrophysics Data System (ADS)

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.

Cobb, S. D.; Higgins, D. B.; Kitchens, L.

2002-01-01

352

Design, synthesis, and characterization of new materials for thermoelectric applications  

NASA Astrophysics Data System (ADS)

Currently, the best known material for thermoelectric refrigeration at room temperature is and alloy of Bi2Te3 and Sb 2Te3. This material has been the basis for room temperature thermoelectric cooling for over 40 years, but its low cooling efficiency (?10% of Carnot Efficiency) has limited its adaptation to small-market specialty applications. Since Bi2Te3 and its alloys have been studied so extensively, it is doubtful that large improvements in efficiency can be made by further modifications of Bi2Te3 (ie. by changing doping or processing of the material). Therefore, this dissertation deals with the discovery and exploration of completely new systems of compounds. The most important parameter for characterizing the efficiency of a thermoelectric material is the dimensionless quantity ZT, where ZT = S2T/rhokappa. Here, S is the thermopower, T is the temperature, kappa is the thermal conductivity, and rho is the electrical resistivity. These variables are not independent of each other, and usually if one of the values is altered by changing composition or doping, the others change as well. Understanding these parameters in depth leads us to several guidelines for searching for better thermoelectric materials and these are discussed in the dissertation. The concept of obtaining highly symmetric crystal structures and also its relation to increasing the value of ZT is discussed. The synthesis of several new quaternary compounds by starting with highly symmetric tetrahedral anion building blocks is presented. While some of these compounds did in fact have high symmetry structures, none were suitable for further studies because they all had large bandgaps. Further systems we explored include heavy metal telluride compounds and compounds that have multiple ordered anions. These systems were chosen based on the concept of minimizing thermal conductivity. A brief chapter on skutterudite materials explores a few new compounds discovered in this highly researched area. The skutterudites are potentially good thermoelectric materials at temperatures above room temperature, however, the compounds discovered were metals and unsuitable for thermoelectric applications. Perhaps the most promising area of research in thermoelectrics presented in this dissertation involves the use of thallium as an alkali metal-like cation. It is shown here that thallium chalcogenides form a wide variety of structures that in many ways mimic the chemistry of alkali metal chalcogenides, yet often form different structures. We present 18 new compounds in that chapter, one of which (Tl1-xSn3+2 xBi7-xSe 14) has an estimated ZT of 0.2--0.3 at room temperature. Since this is not an optimized value, the value of ZT may be able to be increased considerably by carefully adjusting the carrier density. Finally, we present a chapter on measuring the various important thermoelectric parameters (S, rho, and kappa). The construction of a new apparatus for such measurements is presented, along with a new method for measuring kappa, which is much more rapid than steady-state methods.

Reynolds, Thomas Kent

353

Dedication to Degradation: The Beauty of Materials Designed to Lay in Ruin  

NASA Astrophysics Data System (ADS)

Degradation of materials is typically perceived to be a negative response in service. Many designs, and materials, have been and are ruined due to corrosion, fatigue, weathering, ultraviolet light, fungal attack, bacterial attack, erosion, wear, electromigration… and on the list goes. However, the carefully controlled and purposeful degradation of materials is a prerequisite for success for some designs—and such ability is a beautiful necessity when it comes to many regenerative biomaterials. In other instances, we must seek first to understand the degradation mechanisms before we can achieve degradation prevention—and the resistance of some materials to degradation is also beautiful. Regardless of whether we try to prevent or elicit degradation, our dedication to degradation of materials is ever present in materials design.

Nychka, John A.; Kruzic, Jaime

2014-04-01

354

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

E-print Network

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 ...

Ceder, Gerbrand

355

Virtual Welded - Joint Design Integrating Advanced Materials and Processing Technology  

SciTech Connect

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.

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

2005-06-30

356

The Animation Design of Fusible Material Based on Graphics  

NASA Astrophysics Data System (ADS)

In the animation production process, often of different elements to describe the fusion state, this paper takes the single phase reaction-feldspar fusion in the process of ceramic body as example, adopts graphics in its graphics technology to generate fusion style animation design, and makes use of the software Visual C + + language to realize the formation process showing the ceramics microstructure with animation procedure.

Yang, Yun; Yang, Hongli

357

The Animation Design of Fusible Material Based on Graphics  

Microsoft Academic Search

\\u000a In the animation production process, often of different elements to describe the fusion state, this paper takes the single\\u000a phase reaction–feldspar fusion in the process of ceramic body as example, adopts graphics in its graphics technology to generate\\u000a fusion style animation design, and makes use of the software Visual C + + language to realize the formation process showing\\u000a the

Yun Yang; Hongli Yang

2011-01-01

358

Design of Nanostructured Materials for Electronic, Thermoelectric, and Optoelectronic Applications  

NASA Astrophysics Data System (ADS)

There is a large interest in tailoring semiconductor nanostructures to display desired electronic, thermal, or optical properties. Nanostructure dimensions are typically between a few and a few hundred nanometers, so they are too large to treat using atomistic methods, yet too small for continuum techniques. Their characteristics are strongly influenced by the properties of the interfaces, such as roughness, surface defects, or adsorbed charges. A major challenge in predicting the properties of nanostructures lies precisely in capturing the complex interplay between the confined particle states and the surface condition. I will review techniques typically used to analyze and predict the electronic, thermal, and optoelectronic properties of semiconductor nanostructures, with particular focus on the verstatility that the ensemble Monte Carlo technique offers in simulating these different transport phenomena. In particular, I will present our results on electronic and thermal transport in nanowires, based on the coupled electronic and thermal ensemble Monte Carlo simulation with confined electron and phonon dispersions. We will take a close look into boundary scattering of electrons and phonons, and features such as phonon localization, and discuss where atomistic simulations naturally come to play to aid in the desription of interfaces. We will then look into the design on strain superlattices for thermoelectric applications and the design of nanowire interfaces for tailoring thermal conduction. We will also examine how efficient transport simulation aids in the design of quantum cascade lasers. Multivalley ensemble Monte Carlo simulation, combined with k.p bandstructrue calculations and the dielectric continuum model, captures the transport of heat and charge in midinfrared quantum cascade lasers, and helps pinpoint the flaws of a laser design and directions for performance improvement through minimized leakage. We also discuss some promising new avenues, such as the simulaiton of high-frequency and transient phenomena in nanostructures using a combination of full electrodynamics together with the transport of charge and heat, from low- temperature ballistic to room-temperature diffusive transport regimes.

Knezevic, Irena

2010-03-01

359

Computational design of new A2BX4 materials  

NASA Astrophysics Data System (ADS)

The A2BX4 family of ternary compounds represents an important class of materials. Members of this group, in addition to being among the earth most abundant materials, also span a significant range of physical properties including ferromagnetism, coexistence of transparency and p-type conductivity, ferroelectricity, etc. Today we know for about 800 A2BX4 compounds that have been characterized experimentally. This is only a portion of nearly 5000 A2BX4 combinations that could be constructed throughout the periodic table. In this talk I will present a systematic theoretical approach, based on ab initio calculations, for predicting new A2BX4 compounds. For a given new A2BX4 combination we find the candidate crystal structures from the classification of the existing A2BX4 in terms of the atomic orbital radii of the constituent A and B atoms (Zhang and Zunger, Adv. Funct. Mat. 20, 1944, 2010). This step is followed by the set of high-throughput ab initio calculations which are used to sort out the ground-state structure and compute the corresponding heat of formation. The stability of a given A2BX4 with respect to decomposition into competing phases is then tested against all possible combinations of known compounds involving the same elements. This is done by comparing the heat of formation of the new ternary and the heats of formation of the competing (existing) binary and ternary compounds. I will also discuss the algorithms for searching the chemical space of ternary compounds in order to find the materials with target properties.

Stevanovic, Vladan

2011-03-01

360

Decoupling interrelated parameters for designing high performance thermoelectric materials.  

PubMed

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

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

2014-04-15

361

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

NASA Technical Reports Server (NTRS)

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.

Cuddihy, E. F.

1982-01-01

362

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

PubMed

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

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

2013-08-16

363

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

NASA Astrophysics Data System (ADS)

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.

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

2013-08-01

364

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

PubMed

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

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

365

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

PubMed Central

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

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

366

n-Channel semiconductor materials design for organic complementary circuits.  

PubMed

Organic semiconductors have unique properties compared to traditional inorganic materials such as amorphous or crystalline silicon. Some important advantages include their adaptability to low-temperature processing on flexible substrates, low cost, amenability to high-speed fabrication, and tunable electronic properties. These features are essential for a variety of next-generation electronic products, including low-power flexible displays, inexpensive radio frequency identification (RFID) tags, and printable sensors, among many other applications. Accordingly, the preparation of new materials based on ?-conjugated organic molecules or polymers has been a central scientific and technological research focus over the past decade. Currently, p-channel (hole-transporting) materials are the leading class of organic semiconductors. In contrast, high-performance n-channel (electron-transporting) semiconductors are relatively rare, but they are of great significance for the development of plastic electronic devices such as organic field-effect transistors (OFETs). In this Account, we highlight the advances our team has made toward realizing moderately and highly electron-deficient n-channel oligomers and polymers based on oligothiophene, arylenediimide, and (bis)indenofluorene skeletons. We have synthesized and characterized a "library" of structurally related semiconductors, and we have investigated detailed structure-property relationships through optical, electrochemical, thermal, microstructural (both single-crystal and thin-film), and electrical measurements. Our results reveal highly informative correlations between structural parameters at various length scales and charge transport properties. We first discuss oligothiophenes functionalized with perfluoroalkyl and perfluoroarene substituents, which represent the initial examples of high-performance n-channel semiconductors developed in this project. The OFET characteristics of these compounds are presented with an emphasis on structure-property relationships. We then examine the synthesis and properties of carbonyl-functionalized oligomers, which constitute second-generation n-channel oligothiophenes, in both vacuum- and solution-processed FETs. These materials have high carrier mobilities and good air stability. In parallel, exceptionally electron-deficient cyano-functionalized arylenediimide derivatives are discussed as early examples of thermodynamically air-stable, high-performance n-channel semiconductors; they exhibit record electron mobilities of up to 0.64 cm(2)/V·s. Furthermore, we provide an overview of highly soluble ladder-type macromolecular semiconductors as OFET components, which combine ambient stability with solution processibility. A high electron mobility of 0.16 cm(2)/V·s is obtained under ambient conditions for solution-processed films. Finally, examples of polymeric n-channel semiconductors with electron mobilities as high as 0.85 cm(2)/V·s are discussed; these constitute an important advance toward fully printed polymeric electronic circuitry. Density functional theory (DFT) computations reveal important trends in molecular physicochemical and semiconducting properties, which, when combined with experimental data, shed new light on molecular charge transport characteristics. Our data provide the basis for a fundamental understanding of charge transport in high-performance n-channel organic semiconductors. Moreover, our results provide a road map for developing functional, complementary organic circuitry, which requires combining p- and n-channel transistors. PMID:21615105

Usta, Hakan; Facchetti, Antonio; Marks, Tobin J

2011-07-19

367

The Role of Engineering Design in Materials Science and Engineering Curricula  

NASA Astrophysics Data System (ADS)

Undergraduate materials engineering curricula diverge from materials science curricula in two important ways. An underlying requirement is to prepare the graduates for industrial positions, so they need a good grounding in processing and statistical methods, as well as a strong set of hands-on skills in materials characterization and metrology. The other distinguishing feature of an engineering education is the focus on design rather than research. In the case of materials science and engineering, the design deliverable is often a process design, a materials selection, or a failure analysis. Some of the features of education for design include the exercise of thinking about the customer's needs, functional requirements of the product, the cost of production, and the broader context of the design project in society. These ideas can be integrated or at least introduced early in the curriculum and in many different types of courses. Materials Science and Engineering programs have the dual requirement of educating both future scientists and future engineers. Graduating baccalaureate students need to be ready for engineering practice, yet many also are being readied for graduate study and research. One aspect of this ambiguity is that research and design activities are not always as clearly differentiated as they are in other engineering programs. How can one undergraduate curriculum be successful at both? One key distinguishing element in engineering practice is engineering design. Design activities occur in many aspects of the profession and may be practiced by both scientists and engineers; however it is engineering curricula, not science curricula, that tend to explicitly focus on developing the skills and methods of design practice in students. Accredited programs within colleges of engineering are required to emphasize engineering practice and design, while still providing the necessary conceptual development of the underlying science. Current practices and emerging ideas concerned with these aspects of materials education will be presented in this talk.

Allen, Emily

2008-03-01

368

Engineering Phage Materials with Desired Peptide Display: Rational Design Sustained through Natural Selection  

E-print Network

-throughput evolutionary screening method called phage display (1, 2). Additionally, research efforts have goneEngineering Phage Materials with Desired Peptide Display: Rational Design Sustained through Natural; Revised Manuscript Received August 24, 2009 Genetic engineering of phage provides novel opportunities

Lee, Seung-Wuk

369

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

E-print Network

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 ...

Kwan, Joyce G

2013-01-01

370

Optical design study in the 1-5?m spectral band with gradient-index materials  

NASA Astrophysics Data System (ADS)

A design study is conducted in the 1-5?m wavelength band for an F/3, 15 degree full field of view, 38mm focal length imaging system. A survey of preferred materials shows the chromatic properties of homogeneous materials in different regions of this spectrum. A survey of GRIN materials, including zinc selenide zinc sulfide GRIN, aluminum oxynitride GRIN, and chalcogenide GRIN, expands the available chromatic properties in this spectral band. Baseline homogeneous triplet designs are explored and compared to previous studies in the literature. The inclusion of a GRIN material in the three element design improves the chromatic correction and results in a system that is nearly diffraction-limited. The three element design is reduced to two elements, where both elements are GRIN, while maintaining comparable performance to the homogeneous triplet.

McCarthy, Peter; Berman, Rebecca; Williams, Daniel J. L.; Yee, Anthony; Moore, Duncan T.

2014-12-01

371

78 FR 37759 - Ocean Dumping; Atchafalaya-West Ocean Dredged Material Disposal Site Designation  

Federal Register 2010, 2011, 2012, 2013, 2014

...ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 228 [EPA-R06-OW-2013-0221; FRL-9826-6] Ocean Dumping; Atchafalaya-West Ocean Dredged Material Disposal Site Designation AGENCY: Environmental Protection Agency (EPA)....

2013-06-24

372

An advanced microcomputer design for processing of semiconductor materials  

NASA Technical Reports Server (NTRS)

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.

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

1988-01-01

373

Material property for designing, analyzing, and fabricating space structures  

NASA Technical Reports Server (NTRS)

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.

Kolkailah, Faysal A.

1991-01-01

374

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

SciTech Connect

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.

Ren, Weiju [ORNL

2008-01-01

375

Design and fabrication of multi-material structures for bioinspired robots.  

PubMed

New multi-material rapid prototyping processes are making possible the design and fabrication of bioinspired robot structures that share some of the desirable properties of animal appendages. The structures combine stiff and compliant materials and incorporate sensors and other discrete components, resulting in robots that are less demanding to control than traditionally designed robots and more robust. Current challenges include extending this approach to the structures that involve microscopic as well as macroscopic features. PMID:19376772

Cutkosky, Mark R; Kim, Sangbae

2009-05-13

376

Life Modeling and Design Analysis for Ceramic Matrix Composite Materials  

NASA Technical Reports Server (NTRS)

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.

2005-01-01

377

Materials modeling by design: applications to amorphous solids  

NASA Astrophysics Data System (ADS)

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.

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

2009-02-01

378

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

NASA Astrophysics Data System (ADS)

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.

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

379

Materials study supporting thermochemical hydrogen cycle sulfuric acid decomposer design  

NASA Astrophysics Data System (ADS)

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.

Peck, Michael S.

380

Presented at 1999 EWEC Effects of Materials Parameters and Design Details on the Fatigue of  

E-print Network

Presented at 1999 EWEC Effects of Materials Parameters and Design Details on the Fatigue@sandia.gov ABSTRACT: This paper presents an analysis of the results of nine years of fatigue testing represented in the U.S. Department of Energy / Montana State University (DOE/MSU) Composite Materials Fatigue Database

381

Systematic design of phononic band-gap materials and structures by topology optimization  

Microsoft Academic Search

Phononic band-gap materials prevent elastic waves in certain frequency ranges from propagating, and they may therefore be used to generate frequency filters, as beam splitters, as sound or vibration protection devices, or as waveguides. In this work we show how topology optimization can be used to design and optimize periodic materials and structures exhibiting phononic band gaps. Firstly, we optimize

Ole Sigmund; Jakob Søndergaard Jensen

2003-01-01

382

Design of materials with extreme thermal expansion using a three-phase topology optimization method  

Microsoft Academic Search

Composites with extremal or unusual thermal expansion coefficients are designed using a three-phase topology optimization method. The composites are made of two different material phases and a void phase. The topology optimization method consists in finding the distribution of material phases that optimizes an objective function (e.g. thermoelastic properties) subject to certain constraints, such as elastic symmetry or volume fractions

O. Sigmund; S. Torquato

1997-01-01

383

Materials and Design 50 (2013) 38-43 Regeneration Technique for Welding Nanostructured Bainite  

E-print Network

match those of the base metal. Keywords: Nanostructured Bainitic Steel; Welded Joint; Regeneration generated during welding process. 2. Experimental procedure 2.1 Materials and experimental procedure HighMaterials and Design 50 (2013) 38-43 1 Regeneration Technique for Welding Nanostructured Bainite K

Cambridge, University of

2013-01-01

384

Learning to Design and Analyze Materials Handling Systems: Developing Multimedia Tools  

ERIC Educational Resources Information Center

In this paper, we describe aspects related to learning and learning assessment including pedagogy, cognition, pilot study and results from the study. This study is conducted for an educational module on "10 Principles of Materials Handling". This module along with another on "Analysis and Design of Integrated Materials Handling Systems" constitute…

Heragu, Sunderesh; Jennings, Sybillyn

2003-01-01

385

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

ERIC Educational Resources Information Center

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…

Forbes, Cory T.; Davis, Elizabeth A.

2010-01-01

386

header for SPIE use Materials Design and Development of Fluoropolymers for Use as Pellicles  

E-print Network

header for SPIE use Materials Design and Development of Fluoropolymers for Use as Pellicles in 157 and development of ultra transparent fluoropolymers suitable for 157 nm soft pellicle applications has produced of 157nm pellicles from these materials, the fluoropolymers must have appropriate physical properties

Rollins, Andrew M.

387

Soft materials design via self assembly of functionalized icosahedral particles  

NASA Astrophysics Data System (ADS)

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.

Muthukumar, Vidyalakshmi Chockalingam

388

Materials design considerations and selection for a large rad waste incinerator  

SciTech Connect

A new incinerator has been built to process self-generated, low level radioactive wastes at the Department of Energy`s Savannah River Site. Wastes include protective clothing and other solid materials used during the handling of radioactive materials, and liquid chemical wastes resulting from chemical and waste management operations. The basic design and materials of construction selected to solve the anticipated corrosion problems from hot acidic gases are reviewed. Problems surfacing during trial runs prior to radioactive operations are discussed.

Vormelker, P.R.; Jenkins, C.F.; Burns, H.H.

1997-01-01

389

DESIGNING OF A MATERIAL HANDLING SYSTEM WITH AUTO-SYNCHRONIZING TECHNIQUE FOR FLEXIBLE PRODUCTIVITY CONTROL  

Microsoft Academic Search

A project work was done within the time frame of January to December 2004 in Islamic University of Technology, Gazipur, Bangladesh. The main objective of this work is to design a Flexible Material Handling System (FMS) that can automatically synchronize its speed as per requirement. The system is designed for two types of conveyor system where the speed of the

M. N. A. CHOWDHURY; M. A. U. PATWARI; M. M. ISLAM

2006-01-01

390

IFMIF, International Fusion Materials Irradiation Facility conceptual design activity cost report  

Microsoft Academic Search

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

Rennich

1996-01-01

391

DREAM Design Challenge Rules and Materials List Strongest and Lightest Bridge!  

E-print Network

DREAM Design Challenge Rules and Materials List Strongest and Lightest Bridge! Objective: Build - Test and Re-Design Week 8 Practice Tearing Down and Reassembly Week 9 DREAM Day Project Demonstration at Rice University Eligibility: In order to qualify to win prizes at the DREAM Day competition, you must

Alvarez, Pedro J.

392

Materials selection for environmentally conscious design via a proposed life cycle environmental performance index  

Microsoft Academic Search

Although product design methods are well developed, the recent rise of environmentally conscious design, which includes materials\\u000a selection as a key element, mandates the development of new engineering tools for decision-making. In this investigation,\\u000a a method for establishing a life cycle environmental performance index is developed; it is envisioned that the index can be\\u000a integrated into an environmentally conscious design

Haihong Huang; Zhifeng Liu; Lei Zhang; John W. Sutherland

2009-01-01

393

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

NASA Technical Reports Server (NTRS)

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.

Bhat, Biliyar N.

2008-01-01

394

The Halogen Bond in the Design of Functional Supramolecular Materials: Recent Advances  

PubMed Central

Halogen bonding is an emerging noncovalent interaction for constructing supramolecular assemblies. Though similar to the more familiar hydrogen bonding, four primary differences between these two interactions make halogen bonding a unique tool for molecular recognition and the design of functional materials. First, halogen bonds tend to be much more directional than (single) hydrogen bonds. Second, the interaction strength scales with the polarizability of the bond-donor atom, a feature that researchers can tune through single-atom mutation. In addition, halogen bonds are hydrophobic whereas hydrogen bonds are hydrophilic. Lastly, the size of the bond-donor atom (halogen) is significantly larger than hydrogen. As a result, halogen bonding provides supramolecular chemists with design tools that cannot be easily met with other types of noncovalent interactions and opens up unprecedented possibilities in the design of smart functional materials. This Account highlights the recent advances in the design of halogen-bond-based functional materials. Each of the unique features of halogen bonding, directionality, tunable interaction strength, hydrophobicity, and large donor atom size, makes a difference. Taking advantage of the hydrophobicity, researchers have designed small-size ion transporters. The large halogen atom size provided a platform for constructing all-organic light-emitting crystals that efficiently generate triplet electrons and have a high phosphorescence quantum yield. The tunable interaction strengths provide tools for understanding light-induced macroscopic motions in photoresponsive azobenzene-containing polymers, and the directionality renders halogen bonding useful in the design on functional supramolecular liquid crystals and gel-phase materials. Although halogen bond based functional materials design is still in its infancy, we foresee a bright future for this field. We expect that materials designed based on halogen bonding could lead to applications in biomimetics, optics/photonics, functional surfaces, and photoswitchable supramolecules. PMID:23805801

2013-01-01

395

The negative index of refraction demystified  

E-print Network

We study electromagnetic wave propagation in mediums in which the effective relative permittivity and the effective relative permeability are allowed to take any value in the upper half of the complex plane. A general condition is derived for the phase velocity to be oppositely directed to the power flow. That extends the recently studied case of propagation in mediums for which the relative permittivity and relative permeability are both simultaneously negative, to include dissipation as well. An illustrative case study demonstrates that in general the spectrum divides into five distinct regions.

M. W. McCall; A. Lakhtakia; W. S. Weiglhofer

2002-04-23

396

The negative index of refraction demystified  

E-print Network

We study electromagnetic wave propagation in mediums in which the effective relative permittivity and the effective relative permeability are allowed to take any value in the upper half of the complex plane. A general condition is derived for the phase velocity to be oppositely directed to the power flow. That extends the recently studied case of propagation in mediums for which the relative permittivity and relative permeability are both simultaneously negative, to include dissipation as well. An illustrative case study demonstrates that in general the spectrum divides into five distinct regions.

McCall, M W; Weiglhofer, W S

2002-01-01

397

Negative index of refraction in optical metamaterials  

Microsoft Academic Search

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

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

2005-01-01

398

Elementary Students' Learning of Materials Science Practices Through Instruction Based on Engineering Design Tasks  

NASA Astrophysics Data System (ADS)

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 students who participated in engineering design-based science instruction with the goal of constructing a stable, quiet, thermally comfortable model house. The learning outcome of materials science practices was assessed by clinical interviews conducted before and after the instruction, and the learning process was assessed by students' workbooks completed during the instruction. The interviews included two materials selection tasks for designing a sturdy stepstool and an insulated pet habitat. Results indicate that: (1) students significantly improved on both materials selection tasks, (2) their gains were significantly positively associated with the degree of completion of their workbooks, and (3) students who were highly engaged with the workbook's reflective record-keeping tasks showed the greatest improvement on the interviews. These findings suggest the important role workbooks can play in facilitating elementary students' learning of science through authentic activity such as engineering design.

Wendell, Kristen Bethke; Lee, Hee-Sun

2010-12-01

399

Identifying target properties for the design of meta-material tank track pads  

NASA Astrophysics Data System (ADS)

On track vehicle systems, track pads are designed to provide traction and support the weight of the vehicle, they have limited service life due to common failure by blowout. According to the literature, blowout is a failure mode caused by overheating due to hysteresis in elastomeric materials during high speed operations. Elastomers are used primarily for their high compliance, which is essential to protect the suspension components and maintain structural integrity of the track pad. The objective of the work is to explore the use of linear elastic meta-materials with optimized topology to replace elastomers and reduce or eliminate the effect of hysteretic loss. This work presents a methodology to design an alternate meta-material that can provide some of the desired elastic properties of the track pads. To determine the requirements for linear elastic meta-materials, dynamic analyses of a rollover event were conducted. From these analyses the complex dependence of the strain history on different strain components is understood. Due to the non-linearity of elastomers, tangent stiffness matrices are required to update the stress states at different strain increments. The elasticity tensors (tangent operators) determined at a set of strain levels, are used as prescribed constitutive parameters to tailor the meta-material unit-cell topology. The optimal material properties according to which the elastomeric track pad is designed with linear elastic material are identified in this work.

Dangeti, Venkata Sampath

400

Analysis of the requirements on modern energetics and their impact on materials design  

NASA Astrophysics Data System (ADS)

We characterized the "design" of explosive materials as represented by the complete suite of engineering specifications on ingredients and processes used in the manufacture of specific components used in various applications. The detonation of explosive materials and the associated high power density of this process have historically been accepted as essential elements of the design. Evolving requirements such as the desire for insensitive munitions and the broadened demands of controlling the power output are producing a new class on energetic materials whose thermo-chemical response to specific intentional trigger mechanisms result in reactive behavior far removed the classical detonation modeling represented by the physics and chemistry of Chapman-Jouguet [CJ] or Zel'dovich, VonNeuman, Doering [ZND] detonation models. Experimental studies of representative designs and analysis of the role of processes controlled by the mesostructure suggest functional paths to establishing the desired output.

Foster, Joseph C., Jr.; Glumac, Nick; Stewart, D. Scott

2012-03-01

401

Analysis of the Requirements on Modern Energetics and Their Impact on Materials Design  

NASA Astrophysics Data System (ADS)

We have characterized the ``design'' of explosive materials as represented by the complete suite of engineering specifications on ingredients and processes used in the manufacture of specific components used in various application. The detonation of explosive materials and the associated high power density of this process has historically been an essential element of the design. Evolving requirements such as the desire for insensitive munitions and broadened demands on the control of the power output are producing a new class on energetic materials whose thermo-chemical response to specific intentional trigger mechanisms result in reactive behavior far removed the classical detonation modeling represented by the physics and chemistry of Chapman-Jouguet [CJ] or Zel'dovich, VonNeuman, Doering [ZND] detonation model. Experimental studies of representative designs and analysis of the role of processes controlled by the mesostructure suggest functional paths to establishing the desired output.

Foster, Joseph C., Jr.; Glumac, Nick; Stewart, D. Scott

2011-06-01

402

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

SciTech Connect

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.

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

1992-08-01

403

Preliminary Design and Investigation of Integrated Compressor with Composite Material Wheel  

NASA Astrophysics Data System (ADS)

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.

Wang, Jifeng; Müller, Norbert

2012-06-01

404

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

SciTech Connect

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.

Dam, Hieu Chi [Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292 (Japan) [Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292 (Japan); Faculty of Physics, Vietnam National University, 334 Nguyen Trai, Hanoi (Viet Nam); Pham, Tien Lam; Ho, Tu Bao [Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292 (Japan)] [Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292 (Japan); Nguyen, Anh Tuan [Faculty of Physics, Vietnam National University, 334 Nguyen Trai, Hanoi (Viet Nam)] [Faculty of Physics, Vietnam National University, 334 Nguyen Trai, Hanoi (Viet Nam); Nguyen, Viet Cuong [HPC Systems, Inc., 3-9-15 Kaigan, Minato-ku, Tokyo 108-0022 (Japan)] [HPC Systems, Inc., 3-9-15 Kaigan, Minato-ku, Tokyo 108-0022 (Japan)

2014-01-28

405

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

NASA Astrophysics Data System (ADS)

We develop a method that combines data mining and first principles calculation to guide the designing of distorted cubane Mn4 +Mn^{3+}_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 Mn4 + and Mn3 + 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.

Dam, Hieu Chi; Pham, Tien Lam; Ho, Tu Bao; Nguyen, Anh Tuan; Nguyen, Viet Cuong

2014-01-01

406

Design of advanced porous graphene materials: from graphene nanomesh to 3D architectures.  

PubMed

In order to make full utilization of the high intrinsic surface area of graphene, recently, porous graphene materials including graphene nanomesh, crumpled graphene and graphene foam, have attracted tremendous attention and research interest, owing to their exceptional porous structure (high surface area, and high pore volume) in combination with the inherent properties of graphene, such as high electronic conductivity, good thermal stability, and excellent mechanical strength. Interestingly, porous graphene materials and their derivatives have been explored in a wide range of applications in the fields of electronic and photonic devices, energy storage, gas separation/storage, oil absorption and sensors. This article reviews recent progress in the synthesis, characterization, properties, and applications of porous graphene materials. We aim to highlight the importance of designing different porous structures of graphene to meet future challenges, and the trend on future design of porous graphene materials is analyzed. PMID:24301688

Jiang, Lili; Fan, Zhuangjun

2014-02-21

407

Materials and mechanical design analysis of boron carbide reactor safety rods. Final report  

SciTech Connect

The purpose of this task was to analyze the materials and mechanical design bases for the new boron carbide safety rod. These analyses included examination of the irradiation response of the materials, chemical compatibility of component materials, moisture considerations for the boron carbide pellets and susceptibility of the rod to corrosion under reactor environmental conditions. A number of issues concerning the mechanical behavior were also addressed. These included: safety rod dynamic response in scram scenarios, flexibility and mishandling behavior, and response to thermal excursions associated with gamma heating. A surveillance program aimed at evaluating the integrity of the safety rods following actual operating conditions and justifying life extension for the rods was also proposed. Based on the experimental testing and analyses associated with this task, it is concluded that the boron carbide safety rod design meets the materials and mechanical criteria for successful operational performance.

Marra, J.C.

1992-04-01

408

Materials and mechanical design analysis of boron carbide reactor safety rods  

SciTech Connect

The purpose of this task was to analyze the materials and mechanical design bases for the new boron carbide safety rod. These analyses included examination of the irradiation response of the materials, chemical compatibility of component materials, moisture considerations for the boron carbide pellets and susceptibility of the rod to corrosion under reactor environmental conditions. A number of issues concerning the mechanical behavior were also addressed. These included: safety rod dynamic response in scram scenarios, flexibility and mishandling behavior, and response to thermal excursions associated with gamma heating. A surveillance program aimed at evaluating the integrity of the safety rods following actual operating conditions and justifying life extension for the rods was also proposed. Based on the experimental testing and analyses associated with this task, it is concluded that the boron carbide safety rod design meets the materials and mechanical criteria for successful operational performance.

Marra, J.C.

1992-04-01

409

Design of electroceramic materials using artificial neural networks and multiobjective evolutionary algorithms.  

PubMed

We describe the computational design of electroceramic materials with optimal permittivity for application as electronic components. Given the difficulty of large-scale manufacture and characterization of these materials, including the theoretical prediction of their materials properties by conventional means, our approach is based on a recently established database containing composition and property information for a wide range of ceramic compounds. The electroceramic materials composition-function relationship is encapsulated by an artificial neural network which is used as one of the objectives in a multiobjective evolutionary algorithm. Evolutionary algorithms are stochastic optimization techniques which we employ to search for optimal materials based on chemical composition. The other objectives optimized include the reliability of the neural network prediction and the overall electrostatic charge of the material. The evolutionary algorithm searches for materials which simultaneously have high relative permittivity, minimum overall charge, and good prediction reliability. We find that we are able to predict a range of new electroceramic materials with varying degrees of reliability. In some cases the materials are similar to those contained in the database; in others, completely new materials are predicted. PMID:18217739

Scott, D J; Manos, S; Coveney, P V

2008-02-01

410

Design of multiphysics actuators using topology optimization – Part I: One-material structures  

Microsoft Academic Search

This is the first part of a two-paper description of the topology optimization method applied to the design of multiphysics actuators and electrothermomechanical systems in particular. The first paper is focussed on one-material structures, the second on two-material structures. The extensions of the topology optimization method in this first part include coupled and non-linear finite element analyses, constitutive modelling of

O. Sigmund

2001-01-01

411

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

SciTech Connect

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.

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

1981-08-01

412

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

413

The effects of the space environment on damping materials and damping designs on flexible structures  

NASA Technical Reports Server (NTRS)

The effects of space environments on damping materials and damping designs on flexible structures were investigated. The following items were examined: damping of flexible spacecraft appendages; composite loss factor (n sub s) vs. time in high vacuum for damped test beams and damping of flexible structures. The STEP experiments show inherent damping of flexible structures in space effective possible damping design configurations for space structures, effects of passively damped components on the system loss factor of flexible structures and the effect of space environment on properties of damping materials.

Kluesener, M. F.

1984-01-01

414

New phase shifters and phased antenna array designs based on ferroelectric materials and CTS technologies  

Microsoft Academic Search

As the search continues for low-cost and high-performance components for the front-end devices for wireless communications systems, some focus has been placed on exploring new and innovative designs based on ferroelectric technology. In this paper, we present new phase-shifter designs and an integrated phased-array antenna system based on the use of multilayer ferroelectric materials and the continuous transverse stub (CTS)

Magdy F. Iskander; Zhijun Zhang; Zhengqing Yun; Robert S. Isom; Michael G. Hawkins; Rudy Emrick; Bruce Bosco; Jennifer Synowczynski; Bonnie Gersten

2001-01-01

415

Comparison of the thermal effects on LWIR optical designs utilizing different infrared optical materials  

NASA Astrophysics Data System (ADS)

The growing demand for lower cost infrared sensors and cameras has focused attention on the need for low cost optics for the long wave and mid-wave infrared region. The thermal properties of chalcogenides provide benefits for optical and optomechanical designers for the athermalization of lens assemblies as compared to Germanium, Zinc Selenide and other more common infrared materials. This investigation reviews typical infrared materials' thermal performance and the effects of temperature on the optical performance of lens systems manufactured from various optical materials.

Huddleston, Jeremy; Symmons, Alan; Pini, Ray

2014-06-01

416

Accelerated materials property predictions and design using motif-based fingerprints  

E-print Network

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...

Huan, Tran Doan; Ramprasad, Rampi

2015-01-01

417

Design and testing criteria for bipolar plate materials for PEM fuel cell applications  

SciTech Connect

Bipolar plates for proton exchange membrane (PEM) fuel cells are currently under development. These plates separate individual cells of the fuel cell stack, and thus must be sufficiently strong to support clamping forces, be electrically conducting, be fitted with flow channels for stack thermal control, be of a low permeability material to separate safely hydrogen and oxygen feed streams, be corrosion resistant, and be fitted with distribution channels to transfer the feed streams over the plate surface. To date, bipolar plate costs dominate stack costs, and therefore future materials need to meet strict cost targets. A first step in the bipolar plate development program is an assessment of design constraints. Such constraints have been estimated and evaluated and are discussed here. Conclusions point to promising advanced materials, such as conductive, corrosion resistant coatings on metal substrates, as candidates for mass production of fuel cell bipolar plates. Possible candidate materials are identified, and testing procedures developed to determine suitability of various materials.

Borup, R.L.; Vanderborgh, N.E.

1995-05-01

418

Materials data requirements for high power target design E. Noah, 4th HPTW, Malm, SE, 2-6 May 2011  

E-print Network

Materials data requirements for high power target design E. Noah, 4th HPTW, Malmö, SE, 2-6 May 2011 Materials Data Requirements For High Power Target Design E. Noah, C. Kharoua, F. Plewinski, P. Sabbagh ESS Target Division 4th HPTW May 2-6, 2011, Malmö #12;Materials data requirements for high power

McDonald, Kirk

419

A Novel Resonant Metallo-Dielectric Structure for Design ofHigh Performance -,U Meta-Materials  

E-print Network

design. A larger quality factor (Q) and smaller loss tangent for the new design is predicted. 2. a-p Meta-Materials for achieving new media with desired figures of merit. Different material properties such as Double Negative, and the other is significant conduction loss in metallic loops. Therefore, the meta-material development

Sarabandi, Kamal

420

Design and measurement of a thin and light absorbing material for space applications  

NASA Astrophysics Data System (ADS)

This paper presents the design, realization and measurement of a thin lightweight absorbing material for space applications. Absorber design is based on high impedance surfaces loaded with resistors and known as a resistive high impedance surface (RHIS). The behavior of RHIS is analyzed at normal and oblique incidences for TE and TM polarizations. Prototypes have been realized and measured. Final design has a reflection coefficient less than 15 dB in S-Band (2-2.3 GHz) at normal incidence and till an angular dispersion of 40 for waves in TE polarization, and 35 for waves in TM polarization. Simulation results are validated by measurement.

Pinto, Yenny; Sarrazin, Julien; Lepage, Anne Claire; Begaud, Xavier; Capet, Nicolas

2014-05-01

421

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

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

422

Nickel cadmium cell designs negative to positive material ratio and precharge levels  

NASA Technical Reports Server (NTRS)

A review is made of the factors affecting the choices of negative-to-positive materials ratio and negative precharge in nickel-cadmium cells. The effects of these variables on performance are given, and the different methods for setting precharge are evaluated. The effects of special operating requirements on the design are also discussed.

Gross, S.

1977-01-01

423

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

ERIC Educational Resources Information Center

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.…

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

2002-01-01

424

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

ERIC Educational Resources Information Center

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…

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

2007-01-01

425

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

E-print Network

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

Abdou, Mohamed

426

An Integrated Phased Array Antenna Design Using Ferroelectric Materials and the Continuous Transverse Stub Technology  

Microsoft Academic Search

In this paper, a new integrated phased array antenna system employing the ferroelectric materials technology for electronic beam steering capabilities is described. The design integrates a ferroelectric coplanar waveguide phase shifter with the continuous transverse stub (CTS) array. The phase shifter employs a multi-dielectric substrate and includes a thin layer of silicon dioxide between the signal conductors and the ferroelectric

Wayne Kim; Magdy F. Iskander; W. Devereux Palmer

2006-01-01

427

Graphic Design: A Sustainable Solution to Manage the Contents of Teaching Materials  

ERIC Educational Resources Information Center

There is a concern that the teaching of subjects is applied not only with support from a set of technological devices, but largely in the proper use of teaching and new technologies. Taking this idea, the authors develop a research and sustainable design that result in educational materials in solid content and technological innovation, also to…

Victor, Garcia Izaguirre; Luisa, Pier Castello Maria; Eduardo, Arvizu Sanchez

2010-01-01

428

Taguchi statistical design and analysis of cleaning methods for spacecraft materials  

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

429

Instructional Design Considerations in Converting Non-CBT Materials into CBT Courses.  

ERIC Educational Resources Information Center

Instructional designers who are asked to convert existing training materials into computer-based training (CBT) must take special precautions to avoid making the product into a sophisticated page turner. Although conversion may save considerable time on subject research and analysis, courses to be delivered through microcomputers may require…

Ng, Raymond

430

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

E-print Network

E11/Es, E22/Es Effective elastic compressive stiffness, in-plane principal directions Es Elastic modulus of solid material {F} Vector of nodal loads G12/Es Effective elastic shear stiffness, in-plane for kth goal X Vector of design variables. In-plane thicknesses of elements in ground structure XL Lower

Seepersad, Carolyn Conner

431

MECH/BIOM-532, Fall 2014 Materials Issues in Mechanical Design Department of Mechanical Engineering  

E-print Network

MECH/BIOM-532, Fall 2014 ­ Materials Issues in Mechanical Design Department of Mechanical Engineering Colorado State University Course Instructor Dr. Troy B. Holland tbhollan@engr.colostate.edu A110 Engineering (970) 491-1961 Office Hours: Wednesday 12- 2pm, or by appointment Discussion: Mon/Wed, 4-5:15PM

432

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

ERIC Educational Resources Information Center

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…

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

2008-01-01

433

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

E-print Network

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

Hickman, Mark

434

Design-optimization and material selection for a femoral-fracture fixation-plate implant  

E-print Network

functional requirements pertaining to attain the required level of fracture-femur fixation and longevityDesign-optimization and material selection for a femoral-fracture fixation-plate implant M and simulations Femoral-fracture fixed-plate implant Optimization a b s t r a c t The problem of size

Grujicic, Mica

435

Accelerating the design of solar thermal fuel materials through high throughput simulations.  

PubMed

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. PMID:25372463

Liu, Yun; Grossman, Jeffrey C

2014-12-10

436

APPLICATION FO FLOW FORMING FOR USE IN RADIOACTIVE MATERIAL PACKAGING DESIGNS  

SciTech Connect

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.

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

2012-07-11

437

Shape optimization and material gradient design of the sharp hot structure  

NASA Astrophysics Data System (ADS)

In this paper, the shape and material gradient of the sharp hot structure are designed and optimized to meet the hypersonic flight conditions. First, based on the single-objective optimization for the volume, the aerodynamic loading and the heat flow, respectively, the genetic algorithm (GA) is employed for optimizing the shape of the sharp hot structure. Second, the shape of the sharp hot structure is optimized using multi-objective GA by means of the objectives of the volume, the aerodynamic loading and the heat flow. Finally, the ABAQUS software is used to simulate both the temperature and the stress distribution with different material gradient distributions for the sharp hot structure. The optimal distributions of gradient materials for the sharp hot structure are proposed. The results will provide an important guidance for the design of the sharp hot structure.

Ma, Yinji; Yao, Xuefeng; Su, Yunquan

2014-10-01

438

A Data Envelopment Analysis Model for Selecting Material Handling System Designs  

NASA Astrophysics Data System (ADS)

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.

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

439

[Design of plant leaf bionic camouflage materials based on spectral analysis].  

PubMed

The influence of structure parameters and contents of plant leaves on their reflectance spectra was analyzed using the PROSPECT model. The result showed that the bionic camouflage materials should be provided with coarse surface and spongy inner structure, the refractive index of main content must be close to that of plant leaves, the contents of materials should contain chlorophyll and water, and the content of C-H bond must be strictly controlled. Based on the analysis above, a novel camouflage material, which was constituted by coarse transparent waterproof surface, chlorophyll, water and spongy material, was designed. The result of verifiable experiment showed that the reflectance spectra of camouflage material exhibited the same characteristics as those of plant leaves. The similarity coefficient of reflectance spectrum of the camouflage material and camphor leaves was 0.988 1, and the characteristics of camouflage material did not change after sunlight treatment for three months. The bionic camouflage material, who exhibited a high spectral similarity with plant leaves and a good weather resistance, will be an available method for reconnaissance of hyperspectral imaging hopefully. PMID:21847955

Yang, Yu-Jie; Liu, Zhi-Ming; Hu, Bi-Ru; Wu, Wen-Jian

2011-06-01

440

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

NASA Technical Reports Server (NTRS)

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.

1973-01-01

441

Alternative routes for highway shipments of radioactive materials and lessons learned from state designations  

SciTech Connect

Pursuant to the Hazardous Materials Transportation Act (HMTA), the Department of Transportation (DOT) has promulgated a comprehensive set of regulations regarding the highway transportation of high-level radioactive materials. These regulations, under docket numbers HM-164 and HM-164A, establish interstate highways as the preferred routes for the transportation of radioactive materials within and through the states. The regulations also provide a methodology by which a state may select altemative routes. First, the state must establish a state routing agency'', defined as an entity authorized to use the state legal process to impose routing requirements on carriers of radioactive material (49 CFR 171.8). Once identified, the state routing agency must select routes in accordance with DOTs Guidelines for Selecting Preferred Highway Routes for Large Quantity Shipments of Radioactive Materials or an equivalent routing analysis. Adjoining states and localities should be consulted on the impact of proposed alternative routes as a prerequisite of final route selection. Lastly, the states must provide written notice to DOT of any alternative route designation before the routes are deemed effective. The purpose of this report is to discuss the lessons learned'' by the five states within the southern region that have designated alternative or preferred routes under the regulations of the Department of Transportation (DOT) established for the transportation of radioactive materials. The document was prepared by reviewing applicable federal laws and regulations, examining state reports and documents and contacting state officials and routing agencies involved in making routing decisions. In undertaking this project, the Southern States Energy Board hopes to reveal the process used by states that have designated alternative routes and thereby share their experiences (i.e., lessons learned) with other southern states that have yet to make designations.

Not Available

1990-07-01

442

Alternative routes for highway shipments of radioactive materials and lessons learned from state designations  

SciTech Connect

Pursuant to the Hazardous Materials Transportation Act (HMTA), the Department of Transportation (DOT) has promulgated a comprehensive set of regulations regarding the highway transportation of high-level radioactive materials. These regulations, under docket numbers HM-164 and HM-164A, establish interstate highways as the preferred routes for the transportation of radioactive materials within and through the states. The regulations also provide a methodology by which a state may select altemative routes. First, the state must establish a ``state routing agency``, defined as an entity authorized to use the state legal process to impose routing requirements on carriers of radioactive material (49 CFR 171.8). Once identified, the state routing agency must select routes in accordance with DOTs Guidelines for Selecting Preferred Highway Routes for Large Quantity Shipments of Radioactive Materials or an equivalent routing analysis. Adjoining states and localities should be consulted on the impact of proposed alternative routes as a prerequisite of final route selection. Lastly, the states must provide written notice to DOT of any alternative route designation before the routes are deemed effective. The purpose of this report is to discuss the ``lessons learned`` by the five states within the southern region that have designated alternative or preferred routes under the regulations of the Department of Transportation (DOT) established for the transportation of radioactive materials. The document was prepared by reviewing applicable federal laws and regulations, examining state reports and documents and contacting state officials and routing agencies involved in making routing decisions. In undertaking this project, the Southern States Energy Board hopes to reveal the process used by states that have designated alternative routes and thereby share their experiences (i.e., lessons learned) with other southern states that have yet to make designations.

Not Available

1990-07-01

443

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

PubMed Central

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

Wang, Cheng; Liu, Demin

2013-01-01

444

Responsive materials: A novel design for enhanced machine-augmented composites  

NASA Astrophysics Data System (ADS)

The concept of novel responsive materials with a displacement conversion capability was further developed through the design of new machine-augmented composites (MACs). Embedded converter machines and MACs with improved geometry were designed and fabricated by multi-material 3D printing. This technique proved to be very effective in fabricating these novel composites with tuneable elastic moduli of the matrix and the embedded machines and excellent bonding between them. Substantial improvement in the displacement conversion efficiency of the new MACs over the existing ones was demonstrated. Also, the new design trebled the energy absorption of the MACs. Applications in energy absorbers as well as mechanical sensors and actuators are thus envisaged. A further type of MACs with conversion ability, viz. conversion of compressive displacements to torsional ones, was also proposed.

Bafekrpour, Ehsan; Molotnikov, Andrey; Weaver, James C.; Brechet, Yves; Estrin, Yuri

2014-01-01

445

Responsive materials: a novel design for enhanced machine-augmented composites.  

PubMed

The concept of novel responsive materials with a displacement conversion capability was further developed through the design of new machine-augmented composites (MACs). Embedded converter machines and MACs with improved geometry were designed and fabricated by multi-material 3D printing. This technique proved to be very effective in fabricating these novel composites with tuneable elastic moduli of the matrix and the embedded machines and excellent bonding between them. Substantial improvement in the displacement conversion efficiency of the new MACs over the existing ones was demonstrated. Also, the new design trebled the energy absorption of the MACs. Applications in energy absorbers as well as mechanical sensors and actuators are thus envisaged. A further type of MACs with conversion ability, viz. conversion of compressive displacements to torsional ones, was also proposed. PMID:24445490

Bafekrpour, Ehsan; Molotnikov, Andrey; Weaver, James C; Brechet, Yves; Estrin, Yuri

2014-01-01

446

Responsive materials: A novel design for enhanced machine-augmented composites  

PubMed Central

The concept of novel responsive materials with a displacement conversion capability was further developed through the design of new machine-augmented composites (MACs). Embedded converter machines and MACs with improved geometry were designed and fabricated by multi-material 3D printing. This technique proved to be very effective in fabricating these novel composites with tuneable elastic moduli of the matrix and the embedded machines and excellent bonding between them. Substantial improvement in the displacement conversion efficiency of the new MACs over the existing ones was demonstrated. Also, the new design trebled the energy absorption of the MACs. Applications in energy absorbers as well as mechanical sensors and actuators are thus envisaged. A further type of MACs with conversion ability, viz. conversion of compressive displacements to torsional ones, was also proposed. PMID:24445490

Bafekrpour, Ehsan; Molotnikov, Andrey; Weaver, James C.; Brechet, Yves; Estrin, Yuri

2014-01-01

447

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

SciTech Connect

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.

Konynenburg, R.A.; McCright, R.D. [Lawrence Livermore National Lab., CA (United States); Roy, A.K. [B and W Fuel Co., Lynchburg, VA (United States); Jones, D.A. [Nevada Univ., Reno, NV (United States)

1995-08-01

448

75 FR 22524 - Ocean Dumping; Designation of Ocean Dredged Material Disposal Sites Offshore of the Siuslaw River...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Disposal Sites Offshore of the Siuslaw River, Oregon AGENCY: Environmental Protection...finalizes the designation of the Siuslaw River ocean dredged material disposal sites pursuant...dispose of material dredged from the Siuslaw River navigation channel, and to provide a...

2010-04-29

449

New classes of piezoelectrics, ferroelectrics, and antiferroelectrics by first-principles high-throughput materials design  

NASA Astrophysics Data System (ADS)

Functional materials, such as piezoelectrics, ferroelectrics, and antiferroelectrics, exhibit large changes with applied fields and stresses. This behavior enables their incorporation into a wide variety of devices in technological fields such as energy conversion/storage and information processing/storage. Discovery of functional materials with improved performance or even new types of responses is thus not only a scientific challenge, but can have major impacts on society. In this talk I will review our efforts to uncover new families of functional materials using a combined crystallographic database/high-throughput first-principles approach. I will describe our work on the design and discovery of thousands of new functional materials, specifically the LiAlSi family as piezoelectrics, the LiGaGe family as ferroelectrics, and the MgSrSi family as antiferroelectrics.

Bennett, Joseph

2013-03-01

450

Geometry and length scale selection in patterned interfaces with application to materials design  

NASA Astrophysics Data System (ADS)

Material improvements in mechanical design have been long related to the chemical modification of its main constituents. In recent years, with the advance in new manufacturing process and material manipulation techniques at the macro-, micro-, and nano-scales, new promising strategies to enhance material performance without a variation on its intrinsic chemical configuration have become possible. In this research we focus on a novel concept by which morphological modifications at the material interface (e.g., geometrical patterns) can be used to significantly improve the interface resistance to crack propagation, towards the development of advanced fracture resistant materials. A detailed combined computational/experimental approach is developed to unveil the crack propagation mechanisms and fracture toughness in interfaces with geometrical patterns (e.g. patterned interfaces). Computational analyses using the finite element numerical method are performed to study the role of the patterned geometry in the crack propagation where no analytic governing equations have been developed yet. A series of double cantilever beam tests were also designed, developed and executed to evaluate the range of validity of the numerical simulation results. Key relationships between the interface resistance to crack propagation and the pattern geometry in the mm-scale were also obtained from the experimental tests analysis. Using linear elastic fracture mechanics, the J-integral method and the cohesive zone model we were able to develop a series of interface design guidelines for fracture resistant material design. The interface fracture toughness was studied with respect to the pattern size and shape, considering failure mechanisms at different material length scales, and between identical and bimaterial interfaces. The role of material elastic-plastic deformation in the toughening with patterned interfaces was also studied. Many results were obtained from the analyses preformed. For example, it was found that on bimaterial interfaces, the pattern geometry can be designed to improve fracture toughness by enhancing plastic deformation. We also found that depending on the bimaterial elastic mismatch, mechanisms such as discontinuous crack growth can reduce the resistance to crack propagation in the interface. We were able to relate the length scale of the fracture process zone to the geometry of the pattern and the interface fracture toughness, and we also developed several simple analytic equations that can be used to explain many mechanisms associated to interface toughening. As such, this research represents a step towards the understanding of crack propagation resistance in patterned interfaces, where the fracture resistance optimization by the modification of their interface morphology at multiple scales is the ultimate goal.

Cordisco, Fernando Agustin

451

Safety Standard for Oxygen and Oxygen Systems: Guidelines for Oxygen System Design, Materials Selection, Operations, Storage, and Transportation  

NASA Technical Reports Server (NTRS)

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.

1996-01-01

452

Dynamic simulation of stent deployment - effects of design, material and coating  

NASA Astrophysics Data System (ADS)

Dynamic finite-element simulations have been carried out to study the effects of cell design, material choice and drug eluting coating on the mechanical behaviour of stents during deployment. Four representative stent designs have been considered, i.e., Palmaz-Schatz, Cypher, Xience and Endeavor. The former two are made of stainless steel while the latter two made of Co-Cr alloy. Geometric model for each design was created using ProEngineer software, and then imported into Abaqus for simulation of the full process of stent deployment within a diseased artery. In all cases, the delivery system was based on the dynamic expansion of a polyurethane balloon under applied internal pressure. Results showed that the expansion is mainly governed by the design, in particular open-cell design (e.g. Endeavor) tends to have greater expansion than closed-cell design (e.g. Cypher). Dogboning effect was strong for slotted tube design (e.g. Palmaz-Schatz) but reduced significantly for sinusoidal design (e.g. Cypher). Under the same pressure, the maximum von Mises stress in the stent was higher for the open-cell designs and located mostly at the inner corners of each cell. For given deformation, stents made of Co-Cr alloys tend to experience higher stress level than those made of stainless steels, mainly due to the difference in material properties. For artery-plaque system, the maximum stress occurred on the stenosis and dogboning led to stress concentration at the ends of the plaque. The drug eluting coating affected the stent expansion by reducing the recoiling phenomenon considerably, but also raised the stress level on the stent due to property mismatch.

Schiavone, A.; Zhao, L. G.; Abdel-Wahab, A. A.

2013-07-01

453

Design and Construction of Field Reversed Configuration Plasma Chamber for Plasma Material Interaction Studies  

NASA Astrophysics Data System (ADS)

A Field Reversed Configuration (FRC) plasma source was designed and constructed to conduct high energy plasma-materials interaction studies. The purpose of these studies is the development of advanced materials for use in plasma based electric propulsion systems and nuclear fusion containment vessels. Outlined within this thesis is the basic concept of FRC plasmoid creation, an overview of the device design and integration of various diagnostics systems for plasma conditions and characterization, discussion on the variety of material defects resulting from the plasma exposure with methods and tools designed for characterization. Using a Michelson interferometer it was determined that the FRC plasma densities are on the order of ~1021 m-3. A novel dynamic pressure probe was created to measure ion velocities averaging 300 km/s. Compensating flux loop arrays were used to measure magnetic field strength and verify the existence of the FRC plasmoid and when used in combination with density measurements it was determined that the average ion temperatures are ~130 eV. X-ray Photoelectron Spectroscopy (XPS) was employed as a means of characterizing the size and shape of the plasma jet in the sample exposure positions. SEM results from preliminary studies reveal significant morphological changes on plasma facing material surfaces, and use of XRD to elucidate fuel gas-ion implantation strain rates correlated to plasma exposure energies.

Smith, DuWayne L.

454

A new design of cemented stem using functionally graded materials (FGM).  

PubMed

One of the most frequent complications of total hip replacement (THR) is aseptic loosening of femoral component which is primarily due to changes of post-operative stress distribution pattern with respect to intact femur. Stress shielding of the femur is known to be a principal factor in aseptic loosening of hip replacements. Many designers show that a stiff stem shields the surrounding bone from mechanical loading causing stress shielding. Others show that reducing stem stiffness promotes higher proximal interface shear stress which increases the risk of proximal interface failure. Therefore, the task of this investigation is to solve these conflicting problems appeared in the cemented total hip replacement. The finite element method and optimization technique are used in order to find the optimal stem material which gives the optimal available stress distribution between the proximal medial femoral bone and the cement mantle interfaces. The stem is designed using the concept of functionally graded material (FGM) instead of using the conventional most common used stem material. The results showed that there are four feasible solutions from the optimization runs. The best of these designs is to use a cemented stem graded from titanium at the upper stem layer to collagen at the lower stem layer. This new cemented stem design completely eliminates the stress shielding problem at the proximal medial femoral region. The stress shielding using the cemented functionally graded stem is reduced by 98% compared to titanium stem. PMID:24840196

Hedia, H S; Aldousari, S M; Abdellatif, A K; Fouda, N

2014-01-01

455

Optimal experimental designs for the estimation of thermal properties of composite materials  

NASA Technical Reports Server (NTRS)

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.

Scott, Elaine P.; Moncman, Deborah A.

1994-01-01

456

The SNL100-02 blade : advanced core material design studies for the Sandia 100-meter blade.  

SciTech Connect

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.

Griffith, Daniel

2013-11-01

457

Rational peptide design for functional materials via molecular self-assembly  

NASA Astrophysics Data System (ADS)

Supra-molecular self-assembly of rationally designed peptides is a promising approach to construct functional materials. This thesis specifically focuses on hydrogels, an important class of materials with potential for applications in tissue engineering, drug delivery and micro-fluidic systems. The objective is to design short peptides that would specifically adopt a stimulus dependent conformation that is strongly amenable to self-assembly resulting in material formation. With this concept the rational design of a 20 amino acid peptide (MAX1) that folds into an amphiphilic beta-hairpin structure and then self-assembles to form a rigid hydrogel under alkaline conditions is presented. The molecular level conformation of MAX1 was characterized using circular dichroism and FTIR spectroscopies. The mesoscale structure of the hydrogel assessed using confocal and transmission electron micron microscopies and neutron scattering techniques shows that peptide self-assembly results in the formation of fibrils that are homogeneously 3 nm in diameter. The mechanical properties of the hydrogel probed using oscillatory rheology shows that MAX1 forms a stiff hydrogel. Since the self-assembly process is coupled to the intra-molecularly folded state of the peptide, stimulus responsiveness can be specifically engineered into the sequence by rational design. This was demonstrated in the design of peptides that form hydrogels in response to a specific stimulus such as temperature, pH or ionic strength. The significance of peptide design in the context of self-assembly and its relationship to the nanostructure was studied by designing a series of peptides derived from MAX1. Evolving from these studies is an understanding of the relationship between molecular level peptide structure and the nanoscale supra-molecular morphology. Based on this, it has been shown that alternate morphologies distinct from those observed with the gel forming peptides, such as non-twisting laminates or tube-like structures can be constructed. Lastly, it is shown that within amphiphilic beta-hairpin peptides, the turn sequence can be used as a design element to control the stiffness of the hydrogel which is an important property from an application point of view. These studies demonstrate that rationally designed peptides are robust building blocks to construct functional materials via molecular self-assembly.

Rajagopal, Karthikan

458

The Impact of Material and Design Criteria on the Assessment of Negligible Creep  

SciTech Connect

Two of the proposed High Temperature Gas Reactors (HTGRs) under consideration for a demonstration plant have the design object of avoiding creep effects during normal operation. The goal of negligible creep could have different interpretations depending upon what failure modes are considered and associated criteria for avoiding the effects of creep. This work addresses the criteria for negligible creep in Subsection NH of Section III of the ASME B&PV Code, other international design codes and some currently suggested criteria modifications and their impact on permissible operating temperatures for various reactor pressure vessel materials. There are a number of other considerations for the selection of vessel material besides avoiding creep effects. Of particular interest for this review are (1) the material s allowable stress level and impact on wall thickness (the goal being to minimize required wall thickness) and (2) ASME Code approval (inclusion as a permitted material in the relevant Section and Subsection of interest) to expedite regulatory review and approval. The application of negligible creep criteria to two of the candidate materials, SA533 and Mod 9Cr-1Mo, and to a potential alternate, normalized and tempered 2 Cr-1Mo, are illustrated and the relative advantages and disadvantages are discussed.

Jetter, Robert I [Consultant; Sham, Sam [ORNL; Swindeman, Robert W [Consultant

2009-01-01

459

Los Alamos National Laboratory new generation standard nuclear material storage container - the SAVY4000 design  

SciTech Connect

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.

Stone, Timothy Amos [Los Alamos National Laboratory

2010-01-01

460

In-Vessel Coil Material Failure Rate Estimates for ITER Design Use  

SciTech Connect

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.

L. C. Cadwallader

2013-01-01