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Sample records for advanced functional materials

  1. Advanced Functional Materials for Energy Related Applications

    NASA Astrophysics Data System (ADS)

    Sasan, Koroush

    The current global heavy dependency on fossil fuels gives rise to two critical problems: I) fossil fuels will be depleted in the near future; II) the release of green house gas CO2 generated by the combustion of fossil fuels contributes to global warming. To potentially address both problems, this dissertation documents three primary areas of investigation related to the development of alternative energy sources: electrocatalysts for fuel cells, photocatalysts for hydrogen generation, and photoreduction catalysts for converting CO2 to CH4. Fuel cells could be a promising source of alternative energy. Decreasing the cost and improving the durability and power density of Pt/C as a catalyst for reducing oxygen are major challenges for developing fuel cells. To address these concerns, we have synthesized a Nitrogen-Sulfur-Iron-doped porous carbon material. Our results indicate that the synthesized catalyst exhibits not only higher current density and stability but also higher tolerance to crossover chemicals than the commercial Pt/C catalyst. More importantly, the synthetic method is simple and inexpensive. Using photocatalysts and solar energy is another potential alternative solution for energy demand. We have synthesized a new biomimetic heterogeneous photocatalyst through the incorporation of homogeneous complex 1 [(i-SCH 2)2NC(O)C5H4N]-Fe2(CO) 6] into the highly robust zirconium-porphyrin based metal-organic framework (ZrPF). As photosensitizer ZrPF absorbs the visible light and produces photoexcited electrons that can be transferred through axial covalent bond to di-nuclear complex 1 for hydrogen generation. Additionally, we have studied the photoreduction of CO2 to CH4 using self-doped TiO2 (Ti+3@TiO 2) as photocatalytic materials. The incorporation of Ti3+ into TiO2 structures narrows the band gap, leading to significantly increased photocatalytic activity for the reduction of CO2 into renewable hydrocarbon fuel in the presence of water vapor under visible

  2. Fabrication and application of advanced functional materials from lignincellulosic biomass

    NASA Astrophysics Data System (ADS)

    Hu, Sixiao

    This dissertation explored the conversion of lignocellulosic biomass into advanced functional materials and their potential applications. Lignocellulosic biomass represents an as-of-yet underutilized renewable source for not only biofuel production but also functional materials fabrication. This renewable source is a great alternative for fossil fuel based chemicals, which could be one of the solutions to energy crisis. In this work, it was demonstrated a variety of advanced materials including functional carbons, metal and silica nanoparticles could be derived from lignocellulosic biomass. Chapter 1 provided overall reviewed of the lignin structures, productions and its utilizations as plastics, absorbents and carbons, as well as the preparation of nano-structured silver, silica and silicon carbide/nitride from biomass. Chapter 2, 3 and 4 discussed the fabrication of highly porous carbons from isolated lignin, and their applications as electric supercapacitors for energy storage. In chapter 2, ultrafine porous carbon fibers were prepared via electrospinning followed by simultaneous carbonization and activation. Chapter 3 covered the fabrication of supercapacitor based on the porous carbon fibers and the investigation of their electrochemical performances. In chapter 4, porous carbon particulates with layered carbon nano plates structures were produced by simple oven-drying followed by simultaneous carbonization and activation. The effects of heat processing parameters on the resulting carbon structures and their electrochemical properties were discussed in details. Chapter 5 and 6 addressed the preparation of silver nanoparticles using lignin. Chapter 5 reported the synthesis, underlying kinetics and mechanism of monodispersed silver nanospheres with diameter less than 25 nm in aqueous solutions using lignin as dual reducing and capping agents. Chapter 6 covered the preparation of silver nanoparticles on electrospun celluloses ultrafine fibers using lignin as both

  3. Analysis of Advanced Thermoelectric Materials and Their Functional Limits

    NASA Technical Reports Server (NTRS)

    Kim, Hyun Jung

    2015-01-01

    The world's demand for energy is increasing dramatically, but the best energy conversion systems operate at approximately 30% efficiency. One way to decrease energy loss is in the recovery of waste heat using thermoelectric (TE) generators. A TE generator is device that generates electricity by exploiting heat flow across a thermal gradient. The efficiency of a TE material for power generation and cooling is determined by the dimensionless Figure of Merit (ZT): ZT = S(exp. 2)sigmaT/?: where S is the Seebeck coefficient, sigma is the electrical conductivity, T is the absolute temperature, and ? is the thermal conductivity. The parameters are not physically independent, but intrinsically coupled since they are a function of the transport properties of electrons. Traditional research on TE materials has focused on synthesizing bulk semiconductor-type materials that have low thermal conductivity and high electrical conductivity affording ZT values of 1. The optimization of the s/? ratio is difficult to achieve using current material formats, as these material constants are complementary. Recent areas of research are focusing on using nanostructural artifacts that introduce specific dislocations and boundary conditions that scatter the phonons. This disrupts the physical link between thermal (phonon) and electrical (electron) transport. The result is that ? is decreased without decreasing s. These material formats give ZT values of up to 2 which represent approximately 18% energy gain from waste heat recovery. The next challenge in developing the next generation of TE materials with superior performance is to tailor the interconnected thermoelectric physical parameters of the material system. In order to approach this problem, the fundamental physics of each parameter S, sigma, and ? need to be physically understood in their context of electron/phonon interaction for the construction of new high ZT thermoelectric devices. Is it possible to overcome the physical limit

  4. Material Innovation in Advancing Organometal Halide Perovskite Functionality.

    PubMed

    Zheng, Fan; Saldana-Greco, Diomedes; Liu, Shi; Rappe, Andrew M

    2015-12-01

    Organometal halide perovskites (OMHPs) have garnered much attention recently for their unprecedented rate of increasing power conversion efficiency (PCE), positioning them as a promising basis for the next-generation photovoltaic devices. However, the gap between the rapid increasing PCE and the incomplete understanding of the structure-property-performance relationship prevents the realization of the true potential of OMHPs. This Perspective aims to provide a concise overview of the current status of OMHP research, highlighting the unique properties of OMHPs that are critical for solar applications but still not adequately explained. Stability and performance challenges of OMHP solar cells are discussed, calling upon combined experimental and theoretical efforts to address these challenges for pioneering commercialization of OMHP solar cells. Various material innovation strategies for improving the performance and stability of OMHPs are surveyed, showing that the OMHP architecture can serve as a promising and robust platform for the design and optimization of materials with desired functionalities. PMID:26631361

  5. Integrative Chemistry: Advanced functional cellular materials bearing multiscale porosity

    NASA Astrophysics Data System (ADS)

    Depardieu, M.; Kinadjian, N.; Backov, R.

    2015-07-01

    With this mini review we show through the sol-gel and emulsion-based Integrative Chemistry how it is possible to trigger materials dimensionality and beyond their functionalities when reaching enhanced applications. In here we focus on 3D macrocellular monolithic foams bearing hierarchical porosities and applications thereof. We first depict the general background of emulsions focusing on concentrated ones, acting as soft templates for the design of PolyHIPE foams, HIPE being the acronym of High Internal Phase Emulsions while encompassing both sol-gel and polymer chemistry. Secondly we extend this approach toward the design of hybrid organic-inorganic foams, labeled Organo-Si(HIPE), where photonics and heterogeneous catalysis applications are addressed. In a third section we show how inorganic Si(HIPE) matrices can be employed as sacrificial hard templates for the generation carbonaceous foams, labeled Carbon(HIPE). These foams being conductive we show applications when employed as electrodes for Li-S battery and as hosts for Li(BH4)-based hydrogen storage.

  6. Ultrathin coatings of nanoporous materials as property enhancements for advanced functional materials.

    SciTech Connect

    Coker, Eric Nicholas

    2010-11-01

    This report summarizes the findings of a five-month LDRD project funded through Sandia's NTM Investment Area. The project was aimed at providing the foundation for the development of advanced functional materials through the application of ultrathin coatings of microporous or mesoporous materials onto the surface of substrates such as silicon wafers. Prior art teaches that layers of microporous materials such as zeolites may be applied as, e.g., sensor platforms or gas separation membranes. These layers, however, are typically several microns to several hundred microns thick. For many potential applications, vast improvements in the response of a device could be realized if the thickness of the porous layer were reduced to tens of nanometers. However, a basic understanding of how to synthesize or fabricate such ultra-thin layers is lacking. This report describes traditional and novel approaches to the growth of layers of microporous materials on silicon wafers. The novel approaches include reduction of the quantity of nutrients available to grow the zeolite layer through minimization of solution volume, and reaction of organic base (template) with thermally-oxidized silicon wafers under a steam atmosphere to generate ultra-thin layers of zeolite MFI.

  7. Advances in dental materials.

    PubMed

    Vaderhobli, Ram M

    2011-07-01

    The use of materials to rehabilitate tooth structures is constantly changing. Over the past decade, newer material processing techniques and technologies have significantly improved the dependability and predictability of dental material for clinicians. The greatest obstacle, however, is in choosing the right combination for continued success. Finding predictable approaches for successful restorative procedures has been the goal of clinical and material scientists. This article provides a broad perspective on the advances made in various classes of dental restorative materials in terms of their functionality with respect to pit and fissure sealants, glass ionomers, and dental composites. PMID:21726695

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

    PubMed Central

    2013-01-01

    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

  9. PREFACE: International Conference on Advanced Structural and Functional Materials Design 2008

    NASA Astrophysics Data System (ADS)

    Kakeshita, Tomoyuki

    2009-07-01

    The Ministry of Education, Culture, Sports, Science and Technology of Japan started the Priority Assistance for the Formation of Worldwide Renowned Centers of Research - Global COE Program. This program is based on the competitive principle where a third party evaluation decides which program to support and to give priority support to the formation of world-class centers of research. Our program Center of Excellence for Advanced Structural and Functional Materials Design was selected as one of 13 programs in the field of Chemistry and Materials Science. This center is composed of two materials-related Departments in the Graduate School of Engineering: Materials and Manufacturing Science and Adaptive Machine Systems, and 4 Research Institutes: Center for Atomic and Molecular Technologies, Welding and Joining Research Institute, Institute of Scientific and Industrial Research and Research Center for Ultra-High Voltage Electron Microscopy. Recently, materials research, particularly that of metallic materials, has specialized only in individual elemental characteristics and narrow specialty fields, and there is a feeling that the original role of materials research has been forgotten. The 6 educational and research organizations which make up the COE program cooperatively try to develop new advanced structural and functional materials and achieve technological breakthrough for their fabrication processes from electronic, atomic, microstructural and morphological standpoints, focusing on their design and application: development of high performance structural materials such as space plane and turbine blades operating under a severe environment, new fabrication and assembling methods for electronic devices, development of evaluation technique for materials reliability, and development of new biomaterials for regeneration of biological hard tissues. The aim of this international conference was to report the scientific progress in our Global COE program and also to discuss

  10. Voltage Induced Buckling Instability, a Means for Advanced Functionality within Soft Materials

    NASA Astrophysics Data System (ADS)

    Tavakol, Behrouz; Beauchamp, Sarah E.; Chawan, Aschvin; Holmes, Douglas P.

    2015-03-01

    Instabilities within structures composed of soft materials may provide advanced functionality. We use the buckling of thin dielectric plates for pumping fluids and controlling the flow rate within microchannels. When exposed to an electric field, a confined dielectric plate buckles out of the plane, and this buckling can stop or enhance the flow rate of surrounding media. Compliant or grease electrodes have conventionally been used to aid in voltage application to both sides of the dielectric film. Here we introduce fluid electrodes, which make this mechanism embeddable into micro devices, enable the buckling at lower voltages, and significantly enhance the rate of deformation. We show that this mechanism can function as a microvalve to control the flow rate, or as a micropump to enhance the flow rate. We also examine buckled shapes of the dielectric film using a scaled-up version with fluid electrodes. These reversible, voltage-induced buckling instabilities can potentially be used in variety of different applications to control or enhance fluid flow in micro devices.

  11. Advanced desiccant materials research

    NASA Astrophysics Data System (ADS)

    Czanderna, A. W.; Thomas, T. M.

    1986-05-01

    The long-range goal of this task is to understand the role of surface phenomena in desiccant cooling materials. The background information includes a brief introduction to desiccant cooling systems (DCS) and the role of the desiccant as a system component. The purpose, background, rationale, and long-term technical approach for studying advanced desiccant materials are then treated. Experimental methods for measuring water vapor sorption by desiccants are described, and the rationale is then given for choosing a quartz crystal microbalance (QCM) for measuring sorption isotherms, rates, and cyclic stability. Background information is given about the QCM, including the quartz crystal resonator itself, the support structure for the quartz crystal, and the advantages and limitations of a QCM. The apparatus assembled and placed into operation during CY 1985 is described. The functions of the principal components of the equipment, i.e., the QCM, vacuum system, pressure gauges, residual gas analyzer, constant temperature bath, and data acquisition system, are described as they relate to the water vapor sorption measurements now under way. The criteria for narrowing the potential candidates as advanced desiccant materials for the initial studies are given. Also given is a list of 20 principal candidate materials identified based on the criteria and data available in the literature.

  12. Advancing Understanding and Design of Functional Materials Through Theoretical and Computational Chemical Physics

    SciTech Connect

    Fuentes-Cabrera, Miguel A; Huang, Jingsong; Jakowski, Jacek; Meunier, V.; Lopez-Benzanilla, Alejandro; Cruz Silva, Eduardo; Sumpter, Bobby G; Beste, Ariana

    2012-01-01

    Theoretical and computational chemical physics and materials science offers great opportunity toward helping solve some of the grand challenges in science and engineering, because structure and properties of molecules, solids, and liquids are direct reflections of the underlying quantum motion of their electrons. With the advent of semilocal and especially nonlocal descriptions of exchange and correlation effects, density functional theory (DFT) can now describe bonding in molecules and solids with an accuracy which, for many classes of systems, is sufficient to compare quantitatively to experiments. It is therefore becoming possible to develop a semiquantitative description of a large number of systems and processes. In this chapter, we briefly review DFT and its various extensions to include nonlocal terms that are important for long-range dispersion interactions that dominate many self-assembly processes, molecular surface adsorption processes, solution processes, and biological and polymeric materials. Applications of DFT toward problems relevant to energy systems, including energy storage materials, functional nanoelectronics/optoelectronics, and energy conversion, are highlighted.

  13. Concept of functionally graded materials for advanced thermal barrier coating applications

    SciTech Connect

    Lee, W.Y.; Stinton, D.P.; Berndt, C.C.; Erdogan, F.; Lee, Y.D.; Mutasim, Z.

    1996-12-01

    This article explores the concept of creating functionally graded metal-ceramic composite microstructures for thermal barrier coatings used in gas-turbine applications. From a thermomechanical perspective, this concept offers the possibility of significantly improving the life and reliability of thermal barrier coatings. However, prior research reveals that progress has been somewhat limited because of the oxidative instability exhibited by some metal-ceramic composite microstructures. The present study addresses some of the materials criteria and research issues associated with preparing chemically stable, yet mechanically durable, graded metal-ceramic microstructures for realistic application environments.

  14. FUNCTIONALIZED SILICA AEROGELS: ADVANCED MATERIALS TO CAPTURE AND IMMOBILIZE RADIOACTIVE IODINE

    SciTech Connect

    Matyas, Josef; Fryxell, Glen E.; Busche, Brad J.; Wallace, Krys; Fifield, Leonard S.

    2011-11-16

    To support the future expansion of nuclear energy, an effective method is needed to capture and safely store radiological iodine-129 released during reprocessing of spent nuclear fuel. Various materials have been investigated to capture and immobilize iodine. In most cases, however, the materials that are effective for capturing iodine cannot subsequently be sintered/densified to create a stable composite that could be a viable waste form. We have developed chemically modified, highly porous, silica aerogels that show sorption capacities higher than 440 mg of I2 per gram at 150 C. An iodine uptake test in dry air containing 4.2 ppm of iodine demonstrated no breakthrough after 3.5 h and indicated a decontamination factor in excess of 310. Preliminary densification tests showed that the I2-loaded aerogels retained more than 92 wt% of I2 after thermal sintering with pressure assistance at 1200 C for 30 min. These high capture and retention efficiencies for I2 can be further improved by optimizing the functionalization process and the chemistry as well as the sintering conditions.

  15. High-Throughput Computational Design of Advanced Functional Materials: Topological Insulators and Two-Dimensional Electron Gas Systems

    NASA Astrophysics Data System (ADS)

    Yang, Kesong

    As a rapidly growing area of materials science, high-throughput (HT) computational materials design is playing a crucial role in accelerating the discovery and development of novel functional materials. In this presentation, I will first introduce the strategy of HT computational materials design, and take the HT discovery of topological insulators (TIs) as a practical example to show the usage of such an approach. Topological insulators are one of the most studied classes of novel materials because of their great potential for applications ranging from spintronics to quantum computers. Here I will show that, by defining a reliable and accessible descriptor, which represents the topological robustness or feasibility of the candidate, and by searching the quantum materials repository aflowlib.org, we have automatically discovered 28 TIs (some of them already known) in five different symmetry families. Next, I will talk about our recent research work on the HT computational design of the perovskite-based two-dimensional electron gas (2DEG) systems. The 2DEG formed on the perovskite oxide heterostructure (HS) has potential applications in next-generation nanoelectronic devices. In order to achieve practical implementation of the 2DEG in the device design, desired physical properties such as high charge carrier density and mobility are necessary. Here I show that, using the same strategy with the HT discovery of TIs, by introducing a series of combinatorial descriptors, we have successfully identified a series of candidate 2DEG systems based on the perovskite oxides. This work provides another exemplar of applying HT computational design approach for the discovery of advanced functional materials.

  16. Advanced Photon Source Upgrade Project - Materials

    ScienceCinema

    Gibbson, Murray;

    2013-04-19

    An upgrade to Advanced Photon Source announced by DOE - http://go.usa.gov/ivZ -- will help scientists break through bottlenecks in materials design in order to develop materials with desirable functions.

  17. Advanced Photon Source Upgrade Project - Materials

    SciTech Connect

    Gibbson, Murray

    2011-01-01

    An upgrade to Advanced Photon Source announced by DOE - http://go.usa.gov/ivZ -- will help scientists break through bottlenecks in materials design in order to develop materials with desirable functions.

  18. Accelerating advanced-materials commercialization

    NASA Astrophysics Data System (ADS)

    Maine, Elicia; Seegopaul, Purnesh

    2016-05-01

    Long commercialization times, high capital costs and sustained uncertainty deter investment in innovation for advanced materials. With appropriate strategies, technology and market uncertainties can be reduced, and the commercialization of advanced materials accelerated.

  19. DEVELOPMENT OF ADVANCED DRILL COMPONENTS FOR BHA USING MICROWAVE TECHNOLOGY INCORPORATING CARBIDE, DIAMOND COMPOSITES AND FUNCTIONALLY GRADED MATERIALS

    SciTech Connect

    Dinesh Agrawal; Rustum Roy

    2003-01-01

    The microwave processing of materials is a new emerging technology with many attractive advantages over the conventional methods. The advantages of microwave technology for various ceramic systems has already been demonstrated and proven. The recent developments at Penn State have succeeded in applying the microwave technology for the commercialization of WC/Co and diamond based cutting and drilling tools, effectively sintering of metallic materials, and fabrication of transparent ceramics for advanced applications. In recent years, the Microwave Processing and Engineering Center at Penn State University in collaboration with our industrial partner, Dennis Tool Co. has succeeded in commercializing the developed microwave technology partially funded by DOE for WC/Co and diamond based cutting and drilling tools for gas and oil exploration operations. In this program we have further developed this technology to make diamond-carbide composites and metal-carbide-diamond functionally graded materials. Several actual product of diamond-carbide composites have been processed in microwave with better performance than the conventional product. The functionally graded composites with diamond as one of the components has been for the first time successfully developed. These are the highlights of the project.

  20. Damage tolerant functionally graded materials for advanced wear and friction applications

    NASA Astrophysics Data System (ADS)

    Prchlik, Lubos

    The research work presented in this dissertation focused on processing effects, microstructure development, characterization and performance evaluation of composite and graded coatings used for friction and wear control. The following issues were addressed. (1) Definition of prerequisites for a successful composite and graded coating formation by means of thermal spraying. (2) Improvement of characterization methods available for homogenous thermally sprayed coating and their extension to composite and graded materials. (3) Development of novel characterization methods specifically for FGMs, with a focus on through thickness property measurement by indentation and in-situ curvature techniques. (4) Design of composite materials with improved properties compared to homogenous coatings. (5) Fabrication and performance assessment of FGM with improved wear and impact damage properties. Materials. The materials studied included several material systems relevant to low friction and contact damage tolerant applications: MO-Mo2C, WC-Co cermets as materials commonly used sliding components of industrial machinery and NiCrAlY/8%-Yttria Partially Stabilized Zirconia composites as a potential solution for abradable sections of gas turbines and aircraft engines. In addition, uniform coatings such as molybdenum and Ni5%Al alloy were evaluated as model system to assess the influence of microstructure variation onto the mechanical property and wear response. Methods. The contact response of the materials was investigated through several techniques. These included methods evaluating the relevant intrinsic coating properties such as elastic modulus, residual stress, fracture toughness, scratch resistance and tests measuring the abrasion and friction-sliding behavior. Dry-sand and wet two-body abrasion testing was performed in addition to traditional ball on disc sliding tests. Among all characterization techniques the spherical indentation deserved most attention and enabled to

  1. Functionally gradient materials for thermal barrier coatings in advanced gas turbine systems

    SciTech Connect

    Banovic, S.W.; Barmak, K.; Chan, H.M.

    1995-10-01

    New designs for advanced gas turbine engines for power production are required to have higher operating temperatures in order to increase efficiency. However, elevated temperatures will increase the magnitude and severity of environmental degradation of critical turbine components (e.g. combustor parts, turbine blades, etc{hor_ellipsis}). To offset this problem, the usage of thermal barrier coatings (TBCs) has become popular by allowing an increase in maximum inlet temperatures for an operating engine. Although thermal barrier technology is over thirty years old, the principle failure mechanism is the spallation of the ceramic coating at or near the ceramic/bond coat interface. Therefore, it is desirable to develop a coating that combines the thermal barrier qualities of the ceramic layer and the corrosion protection by the metallic bond coat without the detrimental effects associated with the localization of the ceramic/metal interface to a single plane.

  2. Colossal Permittivity in Advanced Functional Heterogeneous Materials: The Relevance of the Local Measurements at Submicron Scale

    NASA Astrophysics Data System (ADS)

    Fiorenza, Patrick; Nigro, Raffaella Lo; Raineri, Vito

    Recently, giant dielectric permittivities (ɛ ' ˜ 104) have been found in several nonferroelectric materials such as CaCu3Ti4O12 (CCTO) (Subramanian et al., J. Solid State Chem. 151:323, 2000; Homes et al., Science 293:673, 2001), doped-NiO (Wu et al., Phys. Rev. Lett. 89:217601, 2002) systems (Li x Ti y Ni1 - x - y O, Li x Si y Ni1 - x - y O, Ki x Ti y Ni1 - x - y O), CuO, (Lin et al., Phys. Rev. B 72:014103, 2005; Sarkar et al., App. Phys. Lett. 92:142901, 2008) etc., and most important, the high ɛ ' values of these materials are almost independent over a wide range of temperature. This is one of the most intriguing features for their implementations in microelectronics devices, and as a consequence, these materials have been subjected to extensive research. Here, an introduction to such materials and to the methods for their dielectric characterization is given. So far, the crucial question is whether the large dielectric response is an intrinsic property of new class of crystals or an extrinsic property originated by a combination of the structural properties and other features such as defects and inhomogeneities. Preliminary, this peculiar dielectric behavior has been explained in powder ceramics by the internal barrier layer capacitor (IBLC) model, that is the presence of semiconducting domains surrounded by thin insulating regions within the crystal microstructure. It has been considered the most appropriate model and it has been generally accepted to explain the giant response of these materials. However, it could not be transferred to single crystals and thin films. In this scenario, scanning probe-based methods (like STM, KPFM, C-AFM, SIM etc) represent the most powerful instrument to understand the colossal permittivity-related physical phenomena, by investigations at nanoscale, clarifying the local effects responsible of the rising of macroscopic giant dielectric responses. Scanning probe microscopy investigations showed the relevance of inhomogeneity

  3. Containerless Processing: Fabrication of Advanced Functional Materials from Undercooled Oxide Melt

    NASA Astrophysics Data System (ADS)

    Kumar, M. S. Vijaya; Ishikawa, Takehiko; Yoda, Shinichi; Kuribayashi, Kazuhiko

    2012-07-01

    Materials science in Microgravity condition is one of newly established cutting edge science field. After the effort of space development and space utilization, microgravity of space environment has been considered as one of novel tools for materials science because it assures containerless levitation. Containerless processing is a promising technique to explore the technologically important materials using rapid solidification of an undercooled melt. Recently, rare-earth ferrites and manganites have attracted great interest towards their wide applications in the field of electronic industry. Among these new hexagonal phases with a space group of P6 _{3}cm are technologically important materials because of multiferroic characteristics, i.e., the coexistence of ferroelectricity and magnetism in one compound. In the present study, containerless solidification of the R-Fe-O, and R-Mn-O melts were carried out to fabricate multiferroics under the controlled Po _{2}. Containerless processing is a promising technique to explore the new materials using rapid solidification of an undercooled melt because it provides large undercooling prior to nucleation. In order to undercool the melt deeply below the melting temperature under a precisely controlled oxygen partial pressure, an aerodynamic levitator (ADL) combined with ZrO _{2} oxygen sensor was designed. A spherical RFeO _{3} and RMnO _{3} sample was levitated by an ADL and completely melted by a CO _{2} laser in an atmosphere with predetermined Po _{2}.The surface temperature of the levitated droplet was monitored by a two-color pyrometer. Then, the droplet was cooled by turning off the CO _{2} laser. The XRD results of the rapidly solidified LuFeO _{3} and LuMnO _{3} samples at Po _{2} of 1x10 ^{5} Pa confirms the existence of the hexagonal metastable LuFeO _{3} phase. On the other hand, orthorhombic RFeO _{3} (R=Yb, Er, Y and Dy)and hexagonal RMnO _{3} (R=Ho-Lu)phases were identified. The cross-sectioned scanning

  4. Advanced composite materials and processes

    NASA Technical Reports Server (NTRS)

    Baucom, Robert M.

    1991-01-01

    Composites are generally defined as two or more individual materials, which, when combined into a single material system, results in improved physical and/or mechanical properties. The freedom of choice of the starting components for composites allows the generation of materials that can be specifically tailored to meet a variety of applications. Advanced composites are described as a combination of high strength fibers and high performance polymer matrix materials. These advanced materials are required to permit future aircraft and spacecraft to perform in extended environments. Advanced composite precursor materials, processes for conversion of these materials to structures, and selected applications for composites are reviewed.

  5. Pressure driven spinning: A multifaceted approach for preparing nanoscaled functionalized fibers, scaffolds, and membranes with advanced materials

    PubMed Central

    Jayasinghe, Suwan N.; Suter, Nicolai

    2010-01-01

    Electrospinning, a flexible jet-based fiber, scaffold, and membrane fabrication approach, has been elucidated as having significance to the heath sciences. Its capabilities have been most impressive as it possesses the ability to spin composite fibers ranging from the nanometer to the micrometer scale. Nonetheless, electrospinning has limitations and hazards, negating its wider exploration, for example, the inability to handle highly conducting suspensions, to its hazardous high voltage. Hence, to date electrospinning has undergone an exhaustive research regime to a point of cliché. Thus, in the work reported herein we unveil a competing technique to electrospinning, which has overcome the above limitations and hazards yet comparable in capabilities. The fiber preparation approach unearthed herein is referred to as “pressure driven spinning (PDS).” The driving mechanism exploited in this fiber spinning process is the pressurized by-pass flow. This mechanism allows the drawing of either micro- or nanosized fibers while processing polymeric suspensions containing a wide range of advanced materials spanning structural, functional, and biological entities. Similar to electrospinning if the collection time of these continuous formed fibers is varied, composite scaffolds and membranes are generated. In keeping with our interests, multicompositional structural entities such as these could have several applications in biology and medicine, for example, ranging from the development of three-dimensional cultures (including disease models) to the development of synthetic tissues and organ structures to advanced approaches for controlled and targeted therapeutics. PMID:20644675

  6. Materials for advanced batteries

    SciTech Connect

    Murphy, D.W.; Broadhead, J.

    1980-01-01

    The requirements of battery systems are considered along with some recent studies of materials of importance in aqueous electrochemical energy-storage systems, lithium-aluminum/iron sulfide batteries, solid electrolytes, molten salt electrolytes in secondary batteries, the recharging of the lithium electrode in organic electrolytes, intercalation electrodes, and interface phenomena in advanced batteries. Attention is given to a lead-acid battery overview, the design and development of micro-reference electrodes for the lithium/metal-sulfide cell system, molten salt electrochemical studies and high energy density cell development, a selenium (IV) cathode in molten chloroaluminates, and the behavior of hard and soft ions in solid electrolytes. Other topics explored are related to the use of the proton conductor hydrogen uranyl phosphate tetrahydrate as the solid electrolyte in hydride-air batteries and hydrogen-oxygen fuel cells, the behavior of the passivating film in Li/SOCl2 cells under various conditions, and the analysis of surface insulating films in lithium nitride crystals.

  7. Advanced neutron absorber materials

    DOEpatents

    Branagan, Daniel J.; Smolik, Galen R.

    2000-01-01

    A neutron absorbing material and method utilizing rare earth elements such as gadolinium, europium and samarium to form metallic glasses and/or noble base nano/microcrystalline materials, the neutron absorbing material having a combination of superior neutron capture cross sections coupled with enhanced resistance to corrosion, oxidation and leaching.

  8. Advanced Materials Technology

    NASA Technical Reports Server (NTRS)

    Blankenship, C. P. (Compiler); Teichman, L. A. (Compiler)

    1982-01-01

    Composites, polymer science, metallic materials (aluminum, titanium, and superalloys), materials processing technology, materials durability in the aerospace environment, ceramics, fatigue and fracture mechanics, tribology, and nondestructive evaluation (NDE) are discussed. Research and development activities are introduced to the nonaerospace industry. In order to provide a convenient means to help transfer aerospace technology to the commercial mainstream in a systematic manner.

  9. PREFACE: Exploring surfaces and buried interfaces of functional materials by advanced x-ray and neutron techniques Exploring surfaces and buried interfaces of functional materials by advanced x-ray and neutron techniques

    NASA Astrophysics Data System (ADS)

    Sakurai, Kenji

    2010-12-01

    measurement. Advances in such technologies are bringing with them new opportunities in surface and buried interface science. In the not too distant future, we will publish a special issue or a book detailing such progress. Exploring surfaces and buried interfaces of functional materials by advanced x-ray and neutron techniques contents Lateral uniformity in chemical composition along a buried reaction front in polymers using off-specular reflectivity Kristopher A Lavery, Vivek M Prabhu, Sushil Satija and Wen-li Wu Orientation dependence of Pd growth on Au electrode surfaces M Takahasi, K Tamura, J Mizuki, T Kondo and K Uosaki A grazing incidence small-angle x-ray scattering analysis on capped Ge nanodots in layer structures Hiroshi Okuda, Masayuki Kato, Keiji Kuno, Shojiro Ochiai, Noritaka Usami, Kazuo Nakajima and Osami Sakata High resolution grazing-incidence in-plane x-ray diffraction for measuring the strain of a Si thin layer Kazuhiko Omote X-ray analysis of mesoporous silica thin films templated by Brij58 surfactant S Fall, M Kulij and A Gibaud Review of the applications of x-ray refraction and the x-ray waveguide phenomenon to estimation of film structures Kouichi Hayashi Epitaxial growth of largely mismatched crystals on H-terminated Si(111) surfaces Hidehito Asaoka Novel TiO2/ZnO multilayer mirrors at 'water-window' wavelengths fabricated by atomic layer epitaxy H Kumagai, Y Tanaka, M Murata, Y Masuda and T Shinagawa Depth-selective structural analysis of thin films using total-external-reflection x-ray diffraction Tomoaki Kawamura and Hiroo Omi Structures of Yb nanoparticle thin films grown by deposition in He and N2 gas atmospheres: AFM and x-ray reflectivity studies Martin Jerab and Kenji Sakurai Ga and As composition profiles in InP/GaInAs/InP heterostructures—x-ray CTR scattering and cross-sectional STM measurements Yoshikazu Takeda, Masao Tabuchi and Arao Nakamura Polarized neutron reflectivity study of a thermally treated MnIr/CoFe exchange bias system Naoki

  10. Shock-loading response of advanced materials

    NASA Astrophysics Data System (ADS)

    Gray, G. T., III

    1993-05-01

    Advanced materials, such as composites (metal, ceramic, or polymer-matrix), intermetallics, foams (metallic or polymeric-based), laminated materials, and nanostructured materials are receiving increasing attention because their properties can be custom tailored specific applications. The high-rate/impact response of advanced materials is relevant to a broad range of service environments such as the crashworthiness of civilian/military vehicles, foreign-object-damage in aerospace, and light-weight armor. Increased utilization of these material classes under dynamic loading conditions requires an understanding of the relationship between high-rate/shock-wave response as a function of microstructure if we are to develop models to predict material behavior. In this paper, the issues relevant to defect generation, storage, and the underlying physical basis needed in predictive models for several advanced materials are reviewed.

  11. Development of advanced thermoelectric materials

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The development of an advanced thermoelectric material for radioisotope thermoelectric generator (RTG) applications is reported. A number of materials were explored. The bulk of the effort, however, was devoted to improving silicon germanium alloys by the addition of gallium phosphide, the synthesis and evaluation of lanthanum chrome sulfide and the formulation of various mixtures of lanthanum sulfide and chrome sulfide. It is found that each of these materials exhibits promise as a thermoelectric material.

  12. Advanced Pressure Boundary Materials

    SciTech Connect

    Santella, Michael L; Shingledecker, John P

    2007-01-01

    Increasing the operating temperatures of fossil power plants is fundamental to improving thermal efficiencies and reducing undesirable emissions such as CO{sub 2}. One group of alloys with the potential to satisfy the conditions required of higher operating temperatures is the advanced ferritic steels such as ASTM Grade 91, 9Cr-2W, and 12Cr-2W. These are Cr-Mo steels containing 9-12 wt% Cr that have martensitic microstructures. Research aimed at increasing the operating temperature limits of the 9-12 wt% Cr steels and optimizing them for specific power plant applications has been actively pursued since the 1970's. As with all of the high strength martensitic steels, specifying upper temperature limits for tempering the alloys and heat treating weldments is a critical issue. To support this aspect of development, thermodynamic analysis was used to estimate how this critical temperature, the A{sub 1} in steel terminology, varies with alloy composition. The results from the thermodynamic analysis were presented to the Strength of Weldments subgroup of the ASME Boiler & Pressure Vessel Code and are being considered in establishing maximum postweld heat treatment temperatures. Experiments are also being planned to verify predictions. This is part of a CRADA project being done with Alstom Power, Inc.

  13. Advanced materials for space

    NASA Technical Reports Server (NTRS)

    Tenney, D. R.; Slemp, W. S.; Long, E. R., Jr.; Sykes, G. F.

    1980-01-01

    The principal thrust of the LSST program is to develop the materials technology required for confident design of large space systems such as antennas and platforms. Areas of research in the FY-79 program include evaluation of polysulfones, measurement of the coefficient of thermal expansion of low expansion composite laminates, thermal cycling effects, and cable technology. The development of new long thermal control coatings and adhesives for use in space is discussed. The determination of radiation damage mechanisms of resin matrix composites and the formulation of new polymer matrices that are inherently more stable in the space environment are examined.

  14. Fatigue of advanced materials

    SciTech Connect

    Dauskardt, R.H.; Ritchie, R.O. . Center for Advanced Materials); Cox, B.N. )

    1993-08-01

    The development of toughened ceramics over the past 10 to 15 years is arguably one of the most important materials breakthroughs of this century. Monolithic and composite ceramic materials having fracture toughnesses up to an order of magnitude higher than those available 20 years ago have been produced using technologies based on scientific understanding and micromechanical models for in situ phase transformation, fiber bridging, ductile-particle toughening, and other toughening mechanisms. The irony of this, however, is that although ceramics can now be seriously considered for many structural applications, they can also, contrary to popular belief, be susceptible to degradation under cyclic fatigue loading. This is true even when the loading is fully compressive. As a result, a great deal of attention is now being paid to ceramic fatigue, largely because of the importance of cyclic loading in many of the potential applications for ceramics, such as gas-turbine and reciprocating engines. However, because the field is in its infancy, only limited fatigue property data have been documented, understanding of salient fatigue mechanisms has not been achieved, and the design of ceramic microstructures for optimum fatigue resistance has yet to be attempted.

  15. Advanced Aerospace Materials by Design

    NASA Technical Reports Server (NTRS)

    Srivastava, Deepak; Djomehri, Jahed; Wei, Chen-Yu

    2004-01-01

    The advances in the emerging field of nanophase thermal and structural composite materials; materials with embedded sensors and actuators for morphing structures; light-weight composite materials for energy and power storage; and large surface area materials for in-situ resource generation and waste recycling, are expected to :revolutionize the capabilities of virtually every system comprising of future robotic and :human moon and mars exploration missions. A high-performance multiscale simulation platform, including the computational capabilities and resources of Columbia - the new supercomputer, is being developed to discover, validate, and prototype next generation (of such advanced materials. This exhibit will describe the porting and scaling of multiscale 'physics based core computer simulation codes for discovering and designing carbon nanotube-polymer composite materials for light-weight load bearing structural and 'thermal protection applications.

  16. Future requirements for advanced materials

    NASA Technical Reports Server (NTRS)

    Olstad, W. B.

    1980-01-01

    Recent advances and future trends in aerospace materials technology are reviewed with reference to metal alloys, high-temperature composites and adhesives, tungsten fiber-reinforced superalloys, hybrid materials, ceramics, new ablative materials, such as carbon-carbon composite and silica tiles used in the Shuttle Orbiter. The technologies of powder metallurgy coupled with hot isostatic pressing, near net forging, complex large shape casting, chopped fiber molding, superplastic forming, and computer-aided design and manufacture are emphasized.

  17. Advanced materials for energy storage.

    PubMed

    Liu, Chang; Li, Feng; Ma, Lai-Peng; Cheng, Hui-Ming

    2010-02-23

    Popularization of portable electronics and electric vehicles worldwide stimulates the development of energy storage devices, such as batteries and supercapacitors, toward higher power density and energy density, which significantly depends upon the advancement of new materials used in these devices. Moreover, energy storage materials play a key role in efficient, clean, and versatile use of energy, and are crucial for the exploitation of renewable energy. Therefore, energy storage materials cover a wide range of materials and have been receiving intensive attention from research and development to industrialization. In this Review, firstly a general introduction is given to several typical energy storage systems, including thermal, mechanical, electromagnetic, hydrogen, and electrochemical energy storage. Then the current status of high-performance hydrogen storage materials for on-board applications and electrochemical energy storage materials for lithium-ion batteries and supercapacitors is introduced in detail. The strategies for developing these advanced energy storage materials, including nanostructuring, nano-/microcombination, hybridization, pore-structure control, configuration design, surface modification, and composition optimization, are discussed. Finally, the future trends and prospects in the development of advanced energy storage materials are highlighted. PMID:20217798

  18. Advanced Materials for Neural Surface Electrodes

    PubMed Central

    Schendel, Amelia A.; Eliceiri, Kevin W.; Williams, Justin C.

    2015-01-01

    Designing electrodes for neural interfacing applications requires deep consideration of a multitude of materials factors. These factors include, but are not limited to, the stiffness, biocompatibility, biostability, dielectric, and conductivity properties of the materials involved. The combination of materials properties chosen not only determines the ability of the device to perform its intended function, but also the extent to which the body reacts to the presence of the device after implantation. Advances in the field of materials science continue to yield new and improved materials with properties well-suited for neural applications. Although many of these materials have been well-established for non-biological applications, their use in medical devices is still relatively novel. The intention of this review is to outline new material advances for neural electrode arrays, in particular those that interface with the surface of the nervous tissue, as well as to propose future directions for neural surface electrode development. PMID:26392802

  19. FTIR characterization of advanced materials

    NASA Technical Reports Server (NTRS)

    Young, P. R.; Chang, A. C.

    1986-01-01

    This paper surveys the application of Fourier transform infrared spectroscopy to the characterization of advanced materials. FTIR sampling techniques including internal and external reflectance and photoacoustic spectroscopy are discussed. Representative examples from the literature of the analysis of resins, fibers, prepregs and composites are reviewed. A discussion of several promising specialized FTIR techniques is also presented.

  20. Electrochemical investigation of functionalized graphene aerogel with different amount of p-phenylenediamine as an advanced electrode material for supercapacitors

    NASA Astrophysics Data System (ADS)

    Gholipour-Ranjbar, Habib; Ganjali, Mohammad Reza; Norouzi, Parviz; Naderi, Hamid Reza

    2016-07-01

    Graphene aerogel has attracted great attention as a new and efficient electrode material for supercapacitors. It can be expected that functionalization of graphene aerogels can further improve their capability. In this study, graphene aerogel functionalized with different amount of p-phenylenediamine (PPD) and the effect of PPD amount on the supercapacitive performance of functionalized graphene aerogel (FGA) was investigated. Structural characterizations showed that PPD molecules initiated graphene aerogel sheets assembly into three-dimensional structures and also increasing PPD amount led to increase in surface area. Electrochemical investigations proved that the FGA with larger pore size showed enhanced supercapacitive performance compared with the FGA with smaller pore size. The optimized FGA-based electrode exhibited outstanding specific capacitance (SC) of 385 F g‑1 at a discharge current density of 1 A g‑1, good rate capability (215 F g‑1 at 20 A g‑1), and exceptionally high cyclic stability by displaying 25% increase in SC after 5000 cycle.

  1. Functional Properties of Nanostructured Materials

    NASA Astrophysics Data System (ADS)

    Kassing, Rainer; Petkov, Plamen; Kulisch, Wilhelm; Popov, Cyril

    This book, based on the lectures and contributions of the NATO ASI on "Functional Properties of Nanostructured Materials", gives a broad overview on this topic, as it combines basic theoretical articles, papers dealing with experimental techniques, and contributions on advanced and up-to-date applications in fields such as microelectronics, optoelectronics, electrochemistry, sensorics, and biotechnology. In addition, it presents an interdisciplinary approach since the authors came from such different fields as physics, chemistry, engineering, materials science and biology.

  2. Materials Requirements for Advanced Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Whitaker, Ann F.; Cook, Mary Beth; Clinton, R. G., Jr.

    2005-01-01

    NASA's mission to "reach the Moon and Mars" will be obtained only if research begins now to develop materials with expanded capabilities to reduce mass, cost and risk to the program. Current materials cannot function satisfactorily in the deep space environments and do not meet the requirements of long term space propulsion concepts for manned missions. Directed research is needed to better understand materials behavior for optimizing their processing. This research, generating a deeper understanding of material behavior, can lead to enhanced implementation of materials for future exploration vehicles. materials providing new approaches for manufacture and new options for In response to this need for more robust materials, NASA's Exploration Systems Mission Directorate (ESMD) has established a strategic research initiative dedicated to materials development supporting NASA's space propulsion needs. The Advanced Materials for Exploration (AME) element directs basic and applied research to understand material behavior and develop improved materials allowing propulsion systems to operate beyond their current limitations. This paper will discuss the approach used to direct the path of strategic research for advanced materials to ensure that the research is indeed supportive of NASA's future missions to the moon, Mars, and beyond.

  3. Engineering living functional materials.

    PubMed

    Chen, Allen Y; Zhong, Chao; Lu, Timothy K

    2015-01-16

    Natural materials, such as bone, integrate living cells composed of organic molecules together with inorganic components. This enables combinations of functionalities, such as mechanical strength and the ability to regenerate and remodel, which are not present in existing synthetic materials. Taking a cue from nature, we propose that engineered 'living functional materials' and 'living materials synthesis platforms' that incorporate both living systems and inorganic components could transform the performance and the manufacturing of materials. As a proof-of-concept, we recently demonstrated that synthetic gene circuits in Escherichia coli enabled biofilms to be both a functional material in its own right and a materials-synthesis platform. To demonstrate the former, we engineered E. coli biofilms into a chemical-inducer-responsive electrical switch. To demonstrate the latter, we engineered E. coli biofilms to dynamically organize biotic-abiotic materials across multiple length scales, template gold nanorods, gold nanowires, and metal/semiconductor heterostructures, and synthesize semiconductor nanoparticles (Chen, A. Y. et al. (2014) Synthesis and patterning of tunable multiscale materials with engineered cells. Nat. Mater. 13, 515-523.). Thus, tools from synthetic biology, such as those for artificial gene regulation, can be used to engineer the spatiotemporal characteristics of living systems and to interface living systems with inorganic materials. Such hybrids can possess novel properties enabled by living cells while retaining desirable functionalities of inorganic systems. These systems, as living functional materials and as living materials foundries, would provide a radically different paradigm of materials performance and synthesis-materials possessing multifunctional, self-healing, adaptable, and evolvable properties that are created and organized in a distributed, bottom-up, autonomously assembled, and environmentally sustainable manner. PMID:25592034

  4. Characterization of advanced electronic materials

    SciTech Connect

    Arko, A.J.; Heffner, R.H.; Hundley, M.F.

    1997-08-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Our goal has been to extend the Laboratory`s competency in nuclear and advanced materials by characterizing (measuring and interpreting) physical properties of advanced electronic materials and in this process to bridge the gap between materials synthesis and theoretical understanding. Attention has focused on discovering new physics by understanding the ground states of materials in which electronic correlations dominate their properties. Among several accomplishments, we have discovered and interpreted pressure-induced superconductivity in CeRh{sub 2}Si{sub 2}, boron content in UBe{sub 13-x}B{sub x} and the origin of small gaps in the spin and charge excitation spectra of Ce{sub 3}Bi{sub 4}Pt{sub 3}, and we provided seminal understanding of large magnetoresistive effects in La{sub 1-x}Ca{sub x}MnO{sub 3}. This work has established new research directions at LANL and elsewhere, involved numerous collaborators from throughout the world and attracted several postdoctoral fellows.

  5. Plasma Processing of Advanced Materials

    SciTech Connect

    Heberlein, Joachim, V.R.; Pfender, Emil; Kortshagen, Uwe

    2005-02-28

    Plasma Processing of Advanced Materials The project had the overall objective of improving our understanding of the influences of process parameters on the properties of advanced superhard materials. The focus was on high rate deposition processes using thermal plasmas and atmospheric pressure glow discharges, and the emphasis on superhard materials was chosen because of the potential impact of such materials on industrial energy use and on the environment. In addition, the development of suitable diagnostic techniques was pursued. The project was divided into four tasks: (1) Deposition of superhard boron containing films using a supersonic plasma jet reactor (SPJR), and the characterization of the deposition process. (2) Deposition of superhard nanocomposite films in the silicon-nitrogen-carbon system using the triple torch plasma reactor (TTPR), and the characterization of the deposition process. (3) Deposition of films consisting of carbon nanotubes using an atmospheric pressure glow discharge reactor. (4) Adapting the Thomson scattering method for characterization of atmospheric pressure non-uniform plasmas with steep spatial gradients and temporal fluctuations. This report summarizes the results.

  6. Engineering Living Functional Materials

    PubMed Central

    2016-01-01

    Natural materials, such as bone, integrate living cells composed of organic molecules together with inorganic components. This enables combinations of functionalities, such as mechanical strength and the ability to regenerate and remodel, which are not present in existing synthetic materials. Taking a cue from nature, we propose that engineered ‘living functional materials’ and ‘living materials synthesis platforms’ that incorporate both living systems and inorganic components could transform the performance and the manufacturing of materials. As a proof-of-concept, we recently demonstrated that synthetic gene circuits in Escherichia coli enabled biofilms to be both a functional material in its own right and a materials-synthesis platform. To demonstrate the former, we engineered E. coli biofilms into a chemical-inducer-responsive electrical switch. To demonstrate the latter, we engineered E. coli biofilms to dynamically organize biotic-abiotic materials across multiple length scales, template gold nanorods, gold nanowires, and metal/semiconductor heterostructures, and synthesize semiconductor nanoparticles (Chen, A. Y. et al. (2014) Synthesis and patterning of tunable multiscale materials with engineered cells. Nat. Mater.13, 515–523.). Thus, tools from synthetic biology, such as those for artificial gene regulation, can be used to engineer the spatiotemporal characteristics of living systems and to interface living systems with inorganic materials. Such hybrids can possess novel properties enabled by living cells while retaining desirable functionalities of inorganic systems. These systems, as living functional materials and as living materials foundries, would provide a radically different paradigm of materials performance and synthesis–materials possessing multifunctional, self-healing, adaptable, and evolvable properties that are created and organized in a distributed, bottom-up, autonomously assembled, and environmentally sustainable manner. PMID

  7. Advanced aircraft engine materials trends

    NASA Technical Reports Server (NTRS)

    Dreshfield, R. L.; Gray, H. R.; Levine, S. R.; Signorelli, R.

    1981-01-01

    Recent activities of the Lewis Research Center are reviewed which are directed toward developing materials for rotating hot section components for aircraft gas turbines. Turbine blade materials activities are directed at increasing metal temperatures approximately 100 C compared to current directionally solidified alloys by use of oxide dispersion strengthening or tungsten alloy wire reinforcement of nickel or iron base superalloys. The application of thermal barrier coatings offers a promise of increasing gas temperatures an additional 100 C with current cooling technology. For turbine disk alloys, activities are directed toward reducing the cost of turbine disks by 50 percent through near net shape fabrication of prealloyed powders as well as towards improved performance. In addition, advanced alloy concepts and fabrication methods for dual alloy disks are being studied as having potential for improving the life of future high performance disks and reducing the amount of strategic materials required in these components.

  8. Functional Hybrid Materials

    NASA Astrophysics Data System (ADS)

    Gómez-Romero, Pedro; Sanchez, Clément

    2004-04-01

    Functional Hybrid Materials consist of both organic and inorganic components, assembled for the purpose of generating desirable properties and functionalities. The aim is twofold: to bring out or enhance advantageous chemical, electrochemical, magnetic or electronic characteristics and at the same time to reduce or wholly suppress undesirable properties or effects. Another target is the creation of entirely new material behavior. The vast number of hybrid material components available has opened up a wide and diversified field of fascinating research. In this book, a team of highly renowned experts gives an in-depth overview, illustrating the superiority of well-designed hybrid materials and their potential applications.

  9. Synthesis of Advanced Energetic Materials

    NASA Astrophysics Data System (ADS)

    Wilson, Rebecca

    2015-06-01

    For a given energetic material, performance is a combination of the rate of energy release and total energy content. Organic and metal-based energetics, respectively, represent the limiting cases, exhibiting strength in one area and weakness in the other. Many organic energetic materials readily detonate, but increasing total energy content using only known energetic functional groups is difficult. In contrast, combustion of aluminum metal can release more than three times the energy available from the same mass of organic explosive, but the rate of energy release is slow relative to detonation, and combustion is often incomplete. Current research in our department seeks to improve both the total energy content of organic explosives and the rate of combustion of aluminum-based materials. Novel arrangements of atoms within energetic molecules, along with new assembly methods for materials, are employed to improve both aspects of performance. In the case of organic energetic materials, novel functional groups can yield compounds with higher density, and therefore greater power, relative to conventional, nitro group-based materials. For aluminum-based materials, progressively smaller particles undergo more rapid and complete combustion. To prevent surface oxidation, one approach is to shield a core of low-valent aluminum atoms with a shell of ligands, while another is to develop aluminum-based fuels that are inherently air-stable. These methods will be discussed in the context of novel energetic materials synthesis. Research Department, NSWC IHEODTD.

  10. Advanced Material Strategies for Tissue Engineering Scaffolds

    PubMed Central

    Engelmayr, George C.; Borenstein, Jeffrey T.; Moutos, Franklin T.; Guilak, Farshid

    2010-01-01

    Tissue engineering seeks to restore the function of diseased or damaged tissues through the use of cells and biomaterial scaffolds. It is now apparent that the next generation of functional tissue replacements will require advanced material strategies to achieve many of the important requirements for long-term success. Here we provide representative examples of engineered skeletal and myocardial tissue constructs in which scaffolds were explicitly designed to match native tissue mechanical properties as well as to promote cell alignment. We discuss recent progress in microfluidic devices that can potentially serve as tissue engineering scaffolds, since mass transport via microvascular-like structures will be essential in the development of tissue engineered constructs on the length scale of native tissues. Given the rapid evolution of the field of tissue engineering, it is important to consider the use of advanced materials in light of the emerging role of genetics, growth factors, bioreactors, and other technologies. PMID:20882506

  11. Session: CSP Advanced Systems: Optical Materials (Presentation)

    SciTech Connect

    Kennedy, C.

    2008-04-01

    The Optical Materials project description is to characterize advanced reflector, perform accelerated and outdoor testing of commercial and experimental reflector materials, and provide industry support.

  12. Advanced High Efficiency Thermoelectric Materials

    NASA Astrophysics Data System (ADS)

    Flanders, Laffite; Cummer, Keith R.; Feinsinger, Joseph; Heshmatpour, Ben

    2006-01-01

    The research effort at Teledyne Energy Systems, Inc., which has been aimed at improving the performance of the currently used thermoelectric (TE) materials has identified a number of improved formulations for the standard n-type PbTe and p-type TAGS. The preliminary test results appear to indicate nearly 50% higher thermal to electric energy conversion efficiency for these new PbTe and TAGS formulations. Effort is continuing to confirm the preliminary test results and validate the materials fabrication processes. Multiple batches of the newly developed TE materials will be prepared and characterized for thermoelectric properties. The selected TE materials will be subjected to degradation analysis and life modeling to determine any deterioration in the TE properties as a function of time and operating temperatures. This effort also includes measurement of sublimation rates as a function of temperature for the selected materials. The results for the initial sublimation tests are quite encouraging and show appreciable reduction in sublimation rate for TAGS 80 and the modified TAGS alloys. Future effort will include determination of effect of sublimation on TE characteristics for the selected TE materials. Microanalysis technique such as optical and electron microscopy, XRD and EDSX will be used to determine the microstructural characteristics of the TE materials at various stages of their simulated operating life. Based on the results of these studies the n-type and p-type materials with the highest power conversion efficiency and the lowest degradation rate will be selected for use in fabrication of future thermoelectric devices.

  13. Advanced materials for space applications

    NASA Astrophysics Data System (ADS)

    Pater, Ruth H.; Curto, Paul A.

    2007-12-01

    Since NASA was created in 1958, over 6400 patents have been issued to the agency—nearly one in a thousand of all patents ever issued in the United States. A large number of these inventions have focused on new materials that have made space travel and exploration of the moon, Mars, and the outer planets possible. In the last few years, the materials developed by NASA Langley Research Center embody breakthroughs in performance and properties that will enable great achievements in space. The examples discussed below offer significant advantages for use in small satellites, i.e., those with payloads under a metric ton. These include patented products such as LaRC SI, LaRC RP 46, LaRC RP 50, PETI-5, TEEK, PETI-330, LaRC CP, TOR-LM and LaRC LCR (patent pending). These and other new advances in nanotechnology engineering, self-assembling nanostructures and multifunctional aerospace materials are presented and discussed below, and applications with significant technological and commercial advantages are proposed.

  14. Advanced Materials for Space Applications

    NASA Technical Reports Server (NTRS)

    Pater, Ruth H.; Curto, Paul A.

    2005-01-01

    Since NASA was created in 1958, over 6400 patents have been issued to the agency--nearly one in a thousand of all patents ever issued in the United States. A large number of these inventions have focused on new materials that have made space travel and exploration of the moon, Mars, and the outer planets possible. In the last few years, the materials developed by NASA Langley Research Center embody breakthroughs in performance and properties that will enable great achievements in space. The examples discussed below offer significant advantages for use in small satellites, i.e., those with payloads under a metric ton. These include patented products such as LaRC SI, LaRC RP 46, LaRC RP 50, PETI-5, TEEK, PETI-330, LaRC CP, TOR-LM and LaRC LCR (patent pending). These and other new advances in nanotechnology engineering, self-assembling nanostructures and multifunctional aerospace materials are presented and discussed below, and applications with significant technological and commercial advantages are proposed.

  15. Materials Advance Chemical Propulsion Technology

    NASA Technical Reports Server (NTRS)

    2012-01-01

    In the future, the Planetary Science Division of NASA's Science Mission Directorate hopes to use better-performing and lower-cost propulsion systems to send rovers, probes, and observers to places like Mars, Jupiter, and Saturn. For such purposes, a new propulsion technology called the Advanced Materials Bipropellant Rocket (AMBR) was developed under NASA's In-Space Propulsion Technology (ISPT) project, located at Glenn Research Center. As an advanced chemical propulsion system, AMBR uses nitrogen tetroxide oxidizer and hydrazine fuel to propel a spacecraft. Based on current research and development efforts, the technology shows great promise for increasing engine operation and engine lifespan, as well as lowering manufacturing costs. In developing AMBR, ISPT has several goals: to decrease the time it takes for a spacecraft to travel to its destination, reduce the cost of making the propulsion system, and lessen the weight of the propulsion system. If goals like these are met, it could result in greater capabilities for in-space science investigations. For example, if the amount (and weight) of propellant required on a spacecraft is reduced, more scientific instruments (and weight) could be added to the spacecraft. To achieve AMBR s maximum potential performance, the engine needed to be capable of operating at extremely high temperatures and pressure. To this end, ISPT required engine chambers made of iridium-coated rhenium (strong, high-temperature metallic elements) that allowed operation at temperatures close to 4,000 F. In addition, ISPT needed an advanced manufacturing technique for better coating methods to increase the strength of the engine chamber without increasing the costs of fabricating the chamber.

  16. Bioinspired Functional Materials

    SciTech Connect

    Zheng, Yongmei; Wang, Jingxia; Hou, Yongping; Bai, Hao; Hu, Michael Z.

    2014-11-25

    This special issue is focused on the nanoscale or micro-/nanoscale structures similar to the biological features in multilevels or hierarchy and so on. Research by mimicking biological systems has shown more impact on many applications due to the well-designed micro-/nanostructures inspired from the biological surfaces or interfaces; therefore, the materials may achieve the fascinating functionality. In conclusion, the bioinspired functional materials may be fabricated by developing novel technology or methods such as synthesis, self-assembly, and soft lithography at micro- or nanolevel or multilevels and, in addition, the multidisciplinary procedures of physical or chemical methods and nanotechnology to mimic the biological multiscale micro-/nanostructures onto one-/two-dimensional surface materials.

  17. Bioinspired Functional Materials

    DOE PAGESBeta

    Zheng, Yongmei; Wang, Jingxia; Hou, Yongping; Bai, Hao; Hu, Michael Z.

    2014-11-25

    This special issue is focused on the nanoscale or micro-/nanoscale structures similar to the biological features in multilevels or hierarchy and so on. Research by mimicking biological systems has shown more impact on many applications due to the well-designed micro-/nanostructures inspired from the biological surfaces or interfaces; therefore, the materials may achieve the fascinating functionality. In conclusion, the bioinspired functional materials may be fabricated by developing novel technology or methods such as synthesis, self-assembly, and soft lithography at micro- or nanolevel or multilevels and, in addition, the multidisciplinary procedures of physical or chemical methods and nanotechnology to mimic the biologicalmore » multiscale micro-/nanostructures onto one-/two-dimensional surface materials.« less

  18. Advanced materials: Information and analysis needs

    SciTech Connect

    Curlee, T.R.; Das, S.; Lee, R.; Trumble, D.

    1990-09-01

    This report presents the findings of a study to identify the types of information and analysis that are needed for advanced materials. The project was sponsored by the US Bureau of Mines (BOM). It includes a conceptual description of information needs for advanced materials and the development and implementation of a questionnaire on the same subject. This report identifies twelve fundamental differences between advanced and traditional materials and discusses the implications of these differences for data and analysis needs. Advanced and traditional materials differ significantly in terms of physical and chemical properties. Advanced material properties can be customized more easily. The production of advanced materials may differ from traditional materials in terms of inputs, the importance of by-products, the importance of different processing steps (especially fabrication), and scale economies. The potential for change in advanced materials characteristics and markets is greater and is derived from the marriage of radically different materials and processes. In addition to the conceptual study, a questionnaire was developed and implemented to assess the opinions of people who are likely users of BOM information on advanced materials. The results of the questionnaire, which was sent to about 1000 people, generally confirm the propositions set forth in the conceptual part of the study. The results also provide data on the categories of advanced materials and the types of information that are of greatest interest to potential users. 32 refs., 1 fig., 12 tabs.

  19. DEVELOPMENT OF ADVANCED DRILL COMPONENTS FOR BHA USING MICROWAVE TECHNOLOGY INCORPORATING CARBIDE, DIAMOND COMPOSITES AND FUNCTIONALLY GRADED MATERIALS

    SciTech Connect

    Dinesh Agrawal; Rustum Roy

    2000-11-01

    The main objective of this program was to develop an efficient and economically viable microwave processing technique to process cobalt cemented tungsten carbide with improved properties for drill-bits for advanced drilling operations for oil, gas, geothermal and excavation industries. The program was completed in three years and successfully accomplished all the states goals in the original proposal. In three years of the program, we designed and built several laboratory scale microwave sintering systems for conducting experiments on Tungsten carbide (WC) based composites in controlled atmosphere. The processing conditions were optimized and various properties were measured. The design of the system was then modified to enable it to process large commercial parts of WC/Co and in large quantities. Two high power (3-6 kW) microwave systems of 2.45 GHz were built for multi samples runs in a batch process. Once the process was optimized for best results, the technology was successfully transferred to our industrial partner, Dennis Tool Co. We helped them to built couple of prototype microwave sintering systems for carbide tool manufacturing. It was found that the microwave processed WC/Co tools are not only cost effective but also exhibited much better overall performance than the standard tools. The results of the field tests performed by Dennis Tool Co. showed remarkable advantage and improvement in their overall performance. For example: wear test shows an increase of 20-30%, corrosion test showed much higher resistance to the acid attack, erosion test exhibited about 15% better resistance than standard sinter-HIP parts. This proves the success of microwave technology for WC/Co based drilling tools. While we have successfully transferred the technology to our industrial partner Dennis Tool Co., they have signed an agreement with Valenite, a world leading WC producer of cutting and drilling tools and wear parts, to push aggressively the new microwave technology in

  20. Advanced Reflector and Absorber Materials (Fact Sheet)

    SciTech Connect

    Not Available

    2010-08-01

    Fact sheet describing NREL CSP Program capabilities in the area of advanced reflector and absorber materials: evaluating performance, determining degradation rates and lifetime, and developing new coatings.

  1. Implications of smart materials in advanced prosthetics

    NASA Astrophysics Data System (ADS)

    Lenoe, Edward M.; Radicic, William N.; Knapp, Michael S.

    1994-05-01

    This research reviews common implant materials and suggests smart materials that may be used as substitutes. Current prosthetic technology, including artificial limbs, joints, and soft and hard tissue, falls short in comprehensive characterization of the chemo-mechanics and materials relationships of the natural tissues and their prosthetic materials counterparts. Many of these unknown chemo-mechanical properties in natural tissue systems maintain cooperative function that allows for optimum efficiency in performance and healing. Traditional prosthetic devices have not taken into account the naturally occurring electro-chemo-mechanical stress- strain relationships that normally exist in a tissue system. Direct mechanical deformation of tissue and cell membrane as a possible use of smart materials may lead to improved prosthetic devices once the mechanosensory systems in living tissues are identified and understood. Smart materials may aid in avoiding interfacial atrophy which is a common cause of prosthetic failure. Finally, we note that advanced composite materials have not received sufficient attention, they should be more widely used in prosthetics. Their structural efficiency allows design and construction of truly efficient bionic devices.

  2. Application of advanced materials to rotating machines

    NASA Technical Reports Server (NTRS)

    Triner, J. E.

    1983-01-01

    In discussing the application of advanced materials to rotating machinery, the following topics are covered: the torque speed characteristics of ac and dc machines, motor and transformer losses, the factors affecting core loss in motors, advanced magnetic materials and conductors, and design tradeoffs for samarium cobalt motors.

  3. Video Fact Sheets: Everyday Advanced Materials

    SciTech Connect

    2015-10-06

    What are Advanced Materials? Ames Laboratory is behind some of the best advanced materials out there. Some of those include: Lead-Free Solder, Photonic Band-Gap Crystals, Terfenol-D, Aluminum-Calcium Power Cable and Nano Particles. Some of these are in products we use every day.

  4. Development of Specialized Advanced Materials Curriculum.

    ERIC Educational Resources Information Center

    Malmgren, Thomas; And Others

    This course is intended to give students a comprehensive experience in current and future manufacturing materials and processes. It familiarizes students with: (1) base of composite materials; (2) composites--a very light, strong material used in spacecraft and stealth aircraft; (3) laminates; (4) advanced materials--especially aluminum alloys;…

  5. Recent Advances in Superhard Materials

    NASA Astrophysics Data System (ADS)

    Zhao, Zhisheng; Xu, Bo; Tian, Yongjun

    2016-07-01

    In superhard materials research, two topics are of central focus. One is to understand hardness microscopically and to establish hardness models with atomic parameters, which can be used to guide the design or prediction of novel superhard crystals. The other is to synthesize superhard materials with enhanced comprehensive performance (i.e., hardness, fracture toughness, and thermal stability), with the ambition of achieving materials harder than natural diamond. In this review, we present recent developments in both areas. The microscopic hardness models of covalent single crystals are introduced and further generalized to polycrystalline materials. Current research progress in novel superhard materials and nanostructuring approaches for high-performance superhard materials are discussed. We also clarify a long-standing controversy about the criterion for performing a reliable indentation hardness measurement.

  6. Micromechanical modeling of advanced materials

    SciTech Connect

    Silling, S.A.; Taylor, P.A.; Wise, J.L.; Furnish, M.D.

    1994-04-01

    Funded as a laboratory-directed research and development (LDRD) project, the work reported here focuses on the development of a computational methodology to determine the dynamic response of heterogeneous solids on the basis of their composition and microstructural morphology. Using the solid dynamics wavecode CTH, material response is simulated on a scale sufficiently fine to explicitly represent the material`s microstructure. Conducting {open_quotes}numerical experiments{close_quotes} on this scale, the authors explore the influence that the microstructure exerts on the material`s overall response. These results are used in the development of constitutive models that take into account the effects of microstructure without explicit representation of its features. Applying this methodology to a glass-reinforced plastic (GRP) composite, the authors examined the influence of various aspects of the composite`s microstructure on its response in a loading regime typical of impact and penetration. As a prerequisite to the microscale modeling effort, they conducted extensive materials testing on the constituents, S-2 glass and epoxy resin (UF-3283), obtaining the first Hugoniot and spall data for these materials. The results of this work are used in the development of constitutive models for GRP materials in transient-dynamics computer wavecodes.

  7. Bioinspired, functional nanoscale materials

    NASA Astrophysics Data System (ADS)

    Jun, In-Kook

    Functional nanomaterials in nature exhibit many unique functions and optical and mechanical properties. Examples of this include the dry adhesion of a gecko's foot, the reduced drag on a shark's skin, the high strength and toughness of nacre, and the superhydrophobic self-cleaning of a lotus leaf. This dissertation is devoted to creating unique and enhanced properties by mimicking such functional materials. We have developed a novel self-pumping membrane, which does not require an applied voltage. The self-pumping membrane harvests chemical energy from a surrounding fluid and uses it for accelerated mass transport across the membrane. A device such as this has promising applications in implantable or remotely operating autonomous devices and membrane-based purification systems. Reproducible and highly active surface enhanced Raman scattering (SERS) substrates were developed using a bottom-up self-assembly technology. With their high sensitivity and good reproducibility, the developed nanostructures (gold nanoparticle and nanohole arrays) as SERS substrates are very promising for applications such as ultra-sensitive detectors for chemicals and reproducible sensors for chemical and biological molecules. Binary colloidal crystals were created using a simple, fast, and scalable spin-coating technology. Although further investigation of the procedure is needed to improve the ordering of particles in the individual layers, the developed assembly technology has a promising outlook in applications such as optical integrated circuits and high-speed optical computing. Inorganic-organic nanocomposites were realized by assembling synthesized gibbsite nanoplatelets using the electrophoretic deposition and infiltration of a monomer followed by polymerization. Via surface modifications of gibbsite nanoplatelets, nanocomposites were further reinforced with covalent linkages between the inorganic platelets and organic matrix.

  8. Advanced Materials for Automotive Application

    NASA Astrophysics Data System (ADS)

    Tisza, M.

    2013-12-01

    In this paper some recent material developments will be overviewed mainly from the point of view of automotive industry. In car industry, metal forming is one of the most important manufacturing processes imposing severe restrictions on materials; these are often contradictory requirements, e.g. high strength simultaneously with good formability, etc. Due to these challenges and the ever increasing demand new material classes have been developed; however, the more and more wide application of high strength materials meeting the requirements stated by the mass reduction lead to increasing difficulties concerning the formability which requires significant technological developments as well. In this paper, the recent materials developments will be overviewed from the point of view of the automotive industry.

  9. On the fracture toughness of advanced materials

    SciTech Connect

    Launey, Maximilien E.; Ritchie, Robert O.

    2008-11-24

    Few engineering materials are limited by their strength; rather they are limited by their resistance to fracture or fracture toughness. It is not by accident that most critical structures, such as bridges, ships, nuclear pressure vessels and so forth, are manufactured from materials that are comparatively low in strength but high in toughness. Indeed, in many classes of materials, strength and toughness are almost mutually exclusive. In the first instance, such resistance to fracture is a function of bonding and crystal structure (or lack thereof), but can be developed through the design of appropriate nano/microstructures. However, the creation of tough microstructures in structural materials, i.e., metals, polymers, ceramics and their composites, is invariably a compromise between resistance to intrinsic damage mechanisms ahead of the tip of a crack (intrinsic toughening) and the formation of crack-tip shielding mechanisms which principally act behind the tip to reduce the effective 'crack-driving force' (extrinsic toughening). Intrinsic toughening is essentially an inherent property of a specific microstructure; it is the dominant form of toughening in ductile (e.g., metallic) materials. However, for most brittle (e.g., ceramic) solids, and this includes many biological materials, it is largely ineffective and toughening conversely must be developed extrinsically, by such shielding mechanisms as crack bridging. From a fracture mechanics perspective, this results in toughening in the form of rising resistance-curve behavior where the fracture resistance actually increases with crack extension. The implication of this is that in many biological and high-strength advanced materials, toughness is developed primarily during crack growth and not for crack initiation. This is an important realization yet is still rarely reflected in the way that toughness is measured, which is invariably involves the use of single-value (crack-initiation) parameters such as the

  10. Advanced Electrical Materials and Component Development

    NASA Technical Reports Server (NTRS)

    Schwarze, Gene E.

    2003-01-01

    The primary means to develop advanced electrical components is to develop new and improved materials for magnetic components (transformers, inductors, etc.), capacitors, and semiconductor switches and diodes. This paper will give a description and status of the internal and external research sponsored by NASA Glenn Research Center on soft magnetic materials, dielectric materials and capacitors, and high quality silicon carbide (SiC) atomically smooth substrates. The rationale for and the benefits of developing advanced electrical materials and components for the PMAD subsystem and also for the total power system will be briefly discussed.

  11. Nuclear material investigations by advanced analytical techniques

    NASA Astrophysics Data System (ADS)

    Degueldre, C.; Kuri, G.; Martin, M.; Froideval, A.; Cammelli, S.; Orlov, A.; Bertsch, J.; Pouchon, M. A.

    2010-10-01

    Advanced analytical techniques have been used to characterize nuclear materials at the Paul Scherrer Institute during the last decade. The analysed materials ranged from reactor pressure vessel (RPV) steels, Zircaloy claddings to fuel samples. The processes studied included copper cluster build up in RPV steels, corrosion, mechanical and irradiation damage behaviour of PWR and BWR cladding materials as well as fuel defect development. The used advanced techniques included muon spin resonance spectroscopy for zirconium alloy defect characterization while fuel element materials were analysed by techniques derived from neutron and X-ray scattering and absorption spectroscopy.

  12. Ion beam processing of advanced electronic materials

    SciTech Connect

    Cheung, N.W.; Marwick, A.D.; Roberto, J.B.; International Business Machines Corp., Yorktown Heights, NY . Thomas J. Watson Research Center; Oak Ridge National Lab., TN )

    1989-01-01

    This report contains research programs discussed at the materials research society symposia on ion beam processing of advanced electronic materials. Major topics include: shallow implantation and solid-phase epitaxy; damage effects; focused ion beams; MeV implantation; high-dose implantation; implantation in III-V materials and multilayers; and implantation in electronic materials. Individual projects are processed separately for the data bases. (CBS)

  13. Advanced Materials for Exploration Task Research Results

    NASA Technical Reports Server (NTRS)

    Cook, M. B. (Compiler); Murphy, K. L.; Schneider, T.

    2008-01-01

    The Advanced Materials for Exploration (AME) Activity in Marshall Space Flight Center s (MSFC s) Exploration Science and Technology Directorate coordinated activities from 2001 to 2006 to support in-space propulsion technologies for future missions. Working together, materials scientists and mission planners identified materials shortfalls that are limiting the performance of long-term missions. The goal of the AME project was to deliver improved materials in targeted areas to meet technology development milestones of NASA s exploration-dedicated activities. Materials research tasks were targeted in five areas: (1) Thermal management materials, (2) propulsion materials, (3) materials characterization, (4) vehicle health monitoring materials, and (5) structural materials. Selected tasks were scheduled for completion such that these new materials could be incorporated into customer development plans.

  14. Characterization and damage evaluation of advanced materials

    NASA Astrophysics Data System (ADS)

    Mitrovic, Milan

    Mechanical characterization of advanced materials, namely magnetostrictive and graphite/epoxy composite materials, is studied in this dissertation, with an emphasis on damage evaluation of composite materials. Consequently, the work in this dissertation is divided into two parts, with the first part focusing on characterization of the magneto-elastic response of magnetostrictlve materials, while the second part of this dissertation describes methods for evaluating the fatigue damage in composite materials. The objective of the first part of this dissertation is to evaluate a nonlinear constitutive relation which more closely depict the magneto-elastic response of magnetostrictive materials. Correlation between experimental and theoretical values indicate that the model adequately predicts the nonlinear strain/field relations in specific regimes, and that the currently employed linear approaches are inappropriate for modeling the response of this material in a structure. The objective of the second part of this dissertation is to unravel the complexities associated with damage events associated with polymeric composite materials. The intent is to characterize and understand the influence of impact and fatigue induced damage on the residual thermo-mechanical properties and compressive strength of composite systems. The influence of fatigue generated matrix cracking and micro-delaminations on thermal expansion coefficient (TEC) and compressive strength is investigated for woven graphite/epoxy composite system. Experimental results indicate that a strong correlation exists between TEC and compressive strength measurements, indicating that TEC measurements can be used as a damage metric for this material systems. The influence of delaminations on the natural frequencies and mode shapes of a composite laminate is also investigated. Based on the changes of these parameters as a function of damage, a methodology for determining the size and location of damage is suggested

  15. Joining of advanced materials by superplastic deformation

    DOEpatents

    Goretta, Kenneth C.; Routbort, Jules L.; Gutierrez-Mora, Felipe

    2008-08-19

    A method for utilizing superplastic deformation with or without a novel joint compound that leads to the joining of advanced ceramic materials, intermetallics, and cermets. A joint formed by this approach is as strong as or stronger than the materials joined. The method does not require elaborate surface preparation or application techniques.

  16. Joining of advanced materials by superplastic deformation

    DOEpatents

    Goretta, Kenneth C.; Routbort, Jules L.; Gutierrez-Mora, Felipe

    2005-12-13

    A method for utilizing superplastic deformation with or without a novel joint compound that leads to the joining of advanced ceramic materials, intermetallics, and cermets. A joint formed by this approach is as strong as or stronger than the materials joined. The method does not require elaborate surface preparation or application techniques.

  17. Methane storage in advanced porous materials.

    PubMed

    Makal, Trevor A; Li, Jian-Rong; Lu, Weigang; Zhou, Hong-Cai

    2012-12-01

    The need for alternative fuels is greater now than ever before. With considerable sources available and low pollution factor, methane is a natural choice as petroleum replacement in cars and other mobile applications. However, efficient storage methods are still lacking to implement the application of methane in the automotive industry. Advanced porous materials, metal-organic frameworks and porous organic polymers, have received considerable attention in sorptive storage applications owing to their exceptionally high surface areas and chemically-tunable structures. In this critical review we provide an overview of the current status of the application of these two types of advanced porous materials in the storage of methane. Examples of materials exhibiting high methane storage capacities are analyzed and methods for increasing the applicability of these advanced porous materials in methane storage technologies described. PMID:22990753

  18. New Advanced Dielectric Materials for Accelerator Applications

    SciTech Connect

    Kanareykin, A.

    2010-11-04

    We present our recent results on the development and experimental testing of advanced dielectric materials that are capable of supporting the high RF electric fields generated by electron beams or pulsed high power microwaves. These materials have been optimized or specially designed for accelerator applications. The materials discussed here include low loss microwave ceramics, quartz, Chemical Vapor Deposition diamonds and nonlinear Barium Strontium Titanate based ferroelectrics.

  19. Functional materials for rechargeable batteries.

    PubMed

    Cheng, Fangyi; Liang, Jing; Tao, Zhanliang; Chen, Jun

    2011-04-19

    There is an ever-growing demand for rechargeable batteries with reversible and efficient electrochemical energy storage and conversion. Rechargeable batteries cover applications in many fields, which include portable electronic consumer devices, electric vehicles, and large-scale electricity storage in smart or intelligent grids. The performance of rechargeable batteries depends essentially on the thermodynamics and kinetics of the electrochemical reactions involved in the components (i.e., the anode, cathode, electrolyte, and separator) of the cells. During the past decade, extensive efforts have been dedicated to developing advanced batteries with large capacity, high energy and power density, high safety, long cycle life, fast response, and low cost. Here, recent progress in functional materials applied in the currently prevailing rechargeable lithium-ion, nickel-metal hydride, lead acid, vanadium redox flow, and sodium-sulfur batteries is reviewed. The focus is on research activities toward the ionic, atomic, or molecular diffusion and transport; electron transfer; surface/interface structure optimization; the regulation of the electrochemical reactions; and the key materials and devices for rechargeable batteries. PMID:21394791

  20. Advanced materials for aircraft engine applications.

    PubMed

    Backman, D G; Williams, J C

    1992-02-28

    A review of advances for aircraft engine structural materials and processes is presented. Improved materials, such as superalloys, and the processes for making turbine disks and blades have had a major impact on the capability of modern gas turbine engines. New structural materials, notably composites and intermetallic materials, are emerging that will eventually further enhance engine performance, reduce engine weight, and thereby enable new aircraft systems. In the future, successful aerospace manufacturers will combine product design and materials excellence with improved manufacturing methods to increase production efficiency, enhance product quality, and decrease the engine development cycle time. PMID:17817782

  1. Advanced Materials and Processing 2010

    NASA Astrophysics Data System (ADS)

    Zhang, Yunfeng; Su, Chun Wei; Xia, Hui; Xiao, Pengfei

    2011-06-01

    Strain sensors made from MWNT/polymer nanocomposites / Gang Yin, Ning Hu and Yuan Li -- Shear band evolution and nanostructure formation in titanium by cold rolling / Dengke Yang, Peter D. Hodgson and Cuie Wen -- Biodegradable Mg-Zr-Ca alloys for bone implant materials / Yuncang Li ... [et al.] -- Hydroxyapatite synthesized from nanosized calcium carbonate via hydrothermal method / Yu-Shiang Wu, Wen-Ku Chang and Min Jou -- Modeling of the magnetization process and orthogonal fluxgate sensitivity of ferromagnetic micro-wire arrays / Fan Jie ... [et al.] -- Fabrication of silicon oxide nanowires on Ni coated silicon substrate by simple heating process / Bo Peng and Kwon-Koo Cho -- Deposition of TiOxNy thin films with various nitrogen flow rate: growth behavior and structural properties / S.-J. Cho ... [et al.] -- Observation on photoluminescence evolution in 300 KeV self-ion implanted and annealed silicon / Yu Yang ... [et al.] -- Facile synthesis of lithium niobate from a novel precursor H[symbol] / Meinan Liu ... [et al.] -- Effects of the buffer layers on the adhesion and antimicrobial properties of the amorphous ZrAlNiCuSi films / Pai-Tsung Chiang ... [et al.] -- Fabrication of ZnO nanorods by electrochemical deposition process and its photovoltaic properties / Jin-Hwa Kim ... [et al.] -- Cryogenic resistivities of NbTiAlVTaLax, CoCrFeNiCu and CoCrFeNiAl high entropy alloys / Xiao Yang and Yong Zhang -- Modeling of centrifugal force field and the effect on filling and solidification in centrifugal casting / Wenbin Sheng, Chunxue Ma and Wanli Gu -- Electrochemical properties of TiO[symbol] nanotube arrays film prepared by anodic oxidation / Young-Jin Choi ... [et al.] -- Effect of Ce additions on high temperature properties of Mg-5Sn-3Al-1Zn alloy / Byoung Soo Kang ... [et al.] -- Sono-electroless plating of Ni-Mo-P film / Atsushi Chiba, Masato Kanou and Wen-Chang Wu -- Diameter dependence of giant magneto-impedance effect in co-based melt extracted amorphous

  2. Advanced Materials and Processing 2010

    NASA Astrophysics Data System (ADS)

    Zhang, Yunfeng; Su, Chun Wei; Xia, Hui; Xiao, Pengfei

    2011-06-01

    Strain sensors made from MWNT/polymer nanocomposites / Gang Yin, Ning Hu and Yuan Li -- Shear band evolution and nanostructure formation in titanium by cold rolling / Dengke Yang, Peter D. Hodgson and Cuie Wen -- Biodegradable Mg-Zr-Ca alloys for bone implant materials / Yuncang Li ... [et al.] -- Hydroxyapatite synthesized from nanosized calcium carbonate via hydrothermal method / Yu-Shiang Wu, Wen-Ku Chang and Min Jou -- Modeling of the magnetization process and orthogonal fluxgate sensitivity of ferromagnetic micro-wire arrays / Fan Jie ... [et al.] -- Fabrication of silicon oxide nanowires on Ni coated silicon substrate by simple heating process / Bo Peng and Kwon-Koo Cho -- Deposition of TiOxNy thin films with various nitrogen flow rate: growth behavior and structural properties / S.-J. Cho ... [et al.] -- Observation on photoluminescence evolution in 300 KeV self-ion implanted and annealed silicon / Yu Yang ... [et al.] -- Facile synthesis of lithium niobate from a novel precursor H[symbol] / Meinan Liu ... [et al.] -- Effects of the buffer layers on the adhesion and antimicrobial properties of the amorphous ZrAlNiCuSi films / Pai-Tsung Chiang ... [et al.] -- Fabrication of ZnO nanorods by electrochemical deposition process and its photovoltaic properties / Jin-Hwa Kim ... [et al.] -- Cryogenic resistivities of NbTiAlVTaLax, CoCrFeNiCu and CoCrFeNiAl high entropy alloys / Xiao Yang and Yong Zhang -- Modeling of centrifugal force field and the effect on filling and solidification in centrifugal casting / Wenbin Sheng, Chunxue Ma and Wanli Gu -- Electrochemical properties of TiO[symbol] nanotube arrays film prepared by anodic oxidation / Young-Jin Choi ... [et al.] -- Effect of Ce additions on high temperature properties of Mg-5Sn-3Al-1Zn alloy / Byoung Soo Kang ... [et al.] -- Sono-electroless plating of Ni-Mo-P film / Atsushi Chiba, Masato Kanou and Wen-Chang Wu -- Diameter dependence of giant magneto-impedance effect in co-based melt extracted amorphous

  3. Advanced materials for geothermal energy processes

    SciTech Connect

    Kukacka, L.E.

    1985-08-01

    The primary goal of the geothermal materials program is to ensure that the private sector development of geothermal energy resources is not constrained by the availability of technologically and economically viable materials of construction. This requires the performance of long-term high risk GHTD-sponsored materials R and D. Ongoing programs described include high temperature elastomers for dynamic sealing applications, advanced materials for lost circulation control, waste utilization and disposal, corrosion resistant elastomeric liners for well casing, and non-metallic heat exchangers. 9 refs.

  4. NASA Thermographic Inspection of Advanced Composite Materials

    NASA Technical Reports Server (NTRS)

    Cramer, K. Elliott

    2004-01-01

    As the use of advanced composite materials continues to increase in the aerospace community, the need for a quantitative, rapid, in situ inspection technology has become a critical concern throughout the industry. In many applications it is necessary to monitor changes in these materials over an extended period of time to determine the effects of various load conditions. Additionally, the detection and characterization of defects such as delaminations, is of great concern. This paper will present the application of infrared thermography to characterize various composite materials and show the advantages of different heat source types. Finally, various analysis methodologies used for quantitative material property characterization will be discussed.

  5. Advanced superconducting materials for electronic applications

    NASA Astrophysics Data System (ADS)

    Beasley, M. R.

    1980-10-01

    Developments in the fabrication of tunnel junctions using Nb- and V-base transition-metal compounds and alloys are summarized. Particular attention is given to the advances in codeposition of these refractory high-transition-temperature superconductors and the properties of thin films deposited by the dual-electron-beam coevaporation technique. Problems associated with these materials are identified, and prospects for the future are discussed. Of the materials reviewed, Nb3Sn is singled out as one deserving further development.

  6. Property Data Summaries for Advanced Materials

    National Institute of Standards and Technology Data Gateway

    SRD 150 NIST Property Data Summaries for Advanced Materials (Web, free access)   Property Data Summaries are topical collections of property values derived from surveys of published data. Thermal, mechanical, structural, and chemical properties are included in the collections.

  7. Continuous spray forming of functionally gradient materials

    SciTech Connect

    McKechnie, T.N.; Richardson, E.H.

    1995-12-01

    Researchers at Plasma Processes Inc. have produced a Functional Gradient Material (FGM) through advanced vacuum plasma spray processing for high heat flux applications. Outlined in this paper are the manufacturing methods used to develop a four component functional gradient material of copper, tungsten, boron, and boron nitride. The FGM was formed with continuous gradients and integral cooling channels eliminating bondlines and providing direct heat transfer from the high temperature exposed surface to a cooling medium. Metallurgical and x-ray diffraction analyses of the materials formed through innovative VPS (vacuum plasma spray) processing are also presented. Applications for this functional gradient structural material range from fusion reactor plasma facing components to missile nose cones to boilers.

  8. Advanced Electrical Materials and Components Being Developed

    NASA Technical Reports Server (NTRS)

    Schwarze, Gene E.

    2004-01-01

    All aerospace systems require power management and distribution (PMAD) between the energy and power source and the loads. The PMAD subsystem can be broadly described as the conditioning and control of unregulated power from the energy source and its transmission to a power bus for distribution to the intended loads. All power and control circuits for PMAD require electrical components for switching, energy storage, voltage-to-current transformation, filtering, regulation, protection, and isolation. Advanced electrical materials and component development technology is a key technology to increasing the power density, efficiency, reliability, and operating temperature of the PMAD. The primary means to develop advanced electrical components is to develop new and/or significantly improved electronic materials for capacitors, magnetic components, and semiconductor switches and diodes. The next important step is to develop the processing techniques to fabricate electrical and electronic components that exceed the specifications of presently available state-of-the-art components. The NASA Glenn Research Center's advanced electrical materials and component development technology task is focused on the following three areas: 1) New and/or improved dielectric materials for the development of power capacitors with increased capacitance volumetric efficiency, energy density, and operating temperature; 2) New and/or improved high-frequency, high-temperature soft magnetic materials for the development of transformers and inductors with increased power density, energy density, electrical efficiency, and operating temperature; 3) Packaged high-temperature, high-power density, high-voltage, and low-loss SiC diodes and switches.

  9. Advanced Industrial Materials (AIM) fellowship program

    SciTech Connect

    McCleary, D.D.

    1997-04-01

    The Advanced Industrial Materials (AIM) Program administers a Graduate Fellowship Program focused toward helping students who are currently under represented in the nation`s pool of scientists and engineers, enter and complete advanced degree programs. The objectives of the program are to: (1) establish and maintain cooperative linkages between DOE and professors at universities with graduate programs leading toward degrees or with degree options in Materials Science, Materials Engineering, Metallurgical Engineering, and Ceramic Engineering, the disciplines most closely related to the AIM Program at Oak Ridge National Laboratory (ORNL); (2) strengthen the capabilities and increase the level of participation of currently under represented groups in master`s degree programs, and (3) offer graduate students an opportunity for practical research experience related to their thesis topic through the three-month research assignment or practicum at ORNL. The program is administered by the Oak Ridge Institute for Science and Education (ORISE).

  10. Structural materials challenges for advanced reactor systems

    NASA Astrophysics Data System (ADS)

    Yvon, P.; Carré, F.

    2009-03-01

    Key technologies for advanced nuclear systems encompass high temperature structural materials, fast neutron resistant core materials, and specific reactor and power conversion technologies (intermediate heat exchanger, turbo-machinery, high temperature electrolytic or thermo-chemical water splitting processes, etc.). The main requirements for the materials to be used in these reactor systems are dimensional stability under irradiation, whether under stress (irradiation creep or relaxation) or without stress (swelling, growth), an acceptable evolution under ageing of the mechanical properties (tensile strength, ductility, creep resistance, fracture toughness, resilience) and a good behavior in corrosive environments (reactor coolant or process fluid). Other criteria for the materials are their cost to fabricate and to assemble, and their composition could be optimized in order for instance to present low-activation (or rapid desactivation) features which facilitate maintenance and disposal. These requirements have to be met under normal operating conditions, as well as in incidental and accidental conditions. These challenging requirements imply that in most cases, the use of conventional nuclear materials is excluded, even after optimization and a new range of materials has to be developed and qualified for nuclear use. This paper gives a brief overview of various materials that are essential to establish advanced systems feasibility and performance for in pile and out of pile applications, such as ferritic/martensitic steels (9-12% Cr), nickel based alloys (Haynes 230, Inconel 617, etc.), oxide dispersion strengthened ferritic/martensitic steels, and ceramics (SiC, TiC, etc.). This article gives also an insight into the various natures of R&D needed on advanced materials, including fundamental research to investigate basic physical and chemical phenomena occurring in normal and accidental operating conditions, lab-scale tests to characterize candidate materials

  11. Advanced fiber/matrix material systems

    NASA Technical Reports Server (NTRS)

    Hartness, J. Timothy

    1991-01-01

    Work completed in Phase 1 of the NASA Advanced Composite Technology program is discussed. Two towpreg forms (commingled yarns and fused powder towpregs) are being characterized under the program. These towpregs will be used to evaluate textile fabrication technologies for advanced aircraft composite structures. The unique characteristic of both of these material forms is that both fiber and matrix resin are handled in a single operation such as weaving, braiding, or fiber placement. The evaluation of both commingled and fused powder towpreg is described. Various polymer materials are considered for both subsonic and supersonic applications. Polymers initially being evaluated include thermoplastic polyimides such as Larc-TPI and New-TPI, thermoplastics such as PEEK and PEKEKK as well as some toughened crosslinked polyimides. Preliminary mechanical properties as well as tow handling are evaluated.

  12. Advanced Ceramic Materials for Future Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Misra, Ajay

    2015-01-01

    With growing trend toward higher temperature capabilities, lightweight, and multifunctionality, significant advances in ceramic matrix composites (CMCs) will be required for future aerospace applications. The presentation will provide an overview of material requirements for future aerospace missions, and the role of ceramics and CMCs in meeting those requirements. Aerospace applications will include gas turbine engines, aircraft structure, hypersonic and access to space vehicles, space power and propulsion, and space communication.

  13. Advanced materials for space nuclear power systems

    SciTech Connect

    Titran, R.H.; Grobstein, T.L. . Lewis Research Center); Ellis, D.L. )

    1991-01-01

    Research on monolithic refractory metal alloys and on metal matrix composites is being conducted at the NASA Lewis Research Center, Cleveland, Ohio, in support of advanced space power systems. The overall philosophy of the research is to develop and characterize new high-temperature power conversion and radiator materials and to provide spacecraft designers with material selection options and design information. Research on three candidate materials (carbide strengthened niobium alloy PWC-11 for fuel cladding, graphite fiber reinforced copper matrix composites (Gr/Cu) for heat rejection fins, and tungsten fiber reinforced niobium matrix composites (W/NB) for fuel containment and structural supports) considered for space power system applications is discussed. Each of these types of materials offers unique advantages for space power applications.

  14. Library of Advanced Materials for Engineering : LAME.

    SciTech Connect

    Hammerand, Daniel Carl; Scherzinger, William Mark

    2007-08-01

    Constitutive modeling is an important aspect of computational solid mechanics. Sandia National Laboratories has always had a considerable effort in the development of constitutive models for complex material behavior. However, for this development to be of use the models need to be implemented in our solid mechanics application codes. In support of this important role, the Library of Advanced Materials for Engineering (LAME) has been developed in Engineering Sciences. The library allows for simple implementation of constitutive models by model developers and access to these models by application codes. The library is written in C++ and has a very simple object oriented programming structure. This report summarizes the current status of LAME.

  15. Advanced Thermoelectric Materials for Radioisotope Thermoelectric Generators

    NASA Technical Reports Server (NTRS)

    Caillat, Thierry; Hunag, C.-K.; Cheng, S.; Chi, S. C.; Gogna, P.; Paik, J.; Ravi, V.; Firdosy, S.; Ewell, R.

    2008-01-01

    This slide presentation reviews the progress and processes involved in creating new and advanced thermoelectric materials to be used in the design of new radioiootope thermoelectric generators (RTGs). In a program with Department of Energy, NASA is working to develop the next generation of RTGs, that will provide significant benefits for deep space missions that NASA will perform. These RTG's are planned to be capable of delivering up to 17% system efficiency and over 12 W/kg specific power. The thermoelectric materials being developed are an important step in this process.

  16. Advances in understanding colonic function.

    PubMed

    Milla, Peter J

    2009-04-01

    The colon is an organ of conservation that salvages water, electrolytes, and energy. The organization of colonic function is determined by the roles played by the luminal flora, the function of the different mucosal epithelial cell types, immunocompetent cells, and the neuromusculature. These different components of the colon interact with one another and with the colonic flora, and different areas of the colon serve different functions. In the normal adult during the course of a day the colon absorbs approximately 1.5 L of fluid, but under the influence of aldosterone increases up to 5 to 6 L. Diarrhoea occurs when secretion exceeds absorptive processes by either small intestinal secretion overwhelming colonic salvage or salvage being impaired by reduced colonic absorption or increased colonic secretion. PMID:19300122

  17. Advanced research workshop: nuclear materials safety

    SciTech Connect

    Jardine, L J; Moshkov, M M

    1999-01-28

    The Advanced Research Workshop (ARW) on Nuclear Materials Safety held June 8-10, 1998, in St. Petersburg, Russia, was attended by 27 Russian experts from 14 different Russian organizations, seven European experts from six different organizations, and 14 U.S. experts from seven different organizations. The ARW was conducted at the State Education Center (SEC), a former Minatom nuclear training center in St. Petersburg. Thirty-three technical presentations were made using simultaneous translations. These presentations are reprinted in this volume as a formal ARW Proceedings in the NATO Science Series. The representative technical papers contained here cover nuclear material safety topics on the storage and disposition of excess plutonium and high enriched uranium (HEU) fissile materials, including vitrification, mixed oxide (MOX) fuel fabrication, plutonium ceramics, reprocessing, geologic disposal, transportation, and Russian regulatory processes. This ARW completed discussions by experts of the nuclear materials safety topics that were not covered in the previous, companion ARW on Nuclear Materials Safety held in Amarillo, Texas, in March 1997. These two workshops, when viewed together as a set, have addressed most nuclear material aspects of the storage and disposition operations required for excess HEU and plutonium. As a result, specific experts in nuclear materials safety have been identified, know each other from their participation in t he two ARW interactions, and have developed a partial consensus and dialogue on the most urgent nuclear materials safety topics to be addressed in a formal bilateral program on t he subject. A strong basis now exists for maintaining and developing a continuing dialogue between Russian, European, and U.S. experts in nuclear materials safety that will improve the safety of future nuclear materials operations in all the countries involved because of t he positive synergistic effects of focusing these diverse backgrounds of

  18. Recent advances in organic semiconducting materials

    NASA Astrophysics Data System (ADS)

    Ostroverkhova, Oksana

    2011-10-01

    Organic semiconductors have attracted attention due to their low cost, easy fabrication, and tunable properties. Applications of organic materials in thin-film transistors, solar cells, light-emitting diodes, sensors, and many other devices have been actively explored. Recent advances in organic synthesis, material processing, and device fabrication led to significant improvements in (opto)electronic device performance. However, a number of challenges remain. These range from lack of understanding of basic physics of intermolecular interactions that determine optical and electronic properties of organic materials to difficulties in controlling film morphology and stability. In this presentation, current state of the field will be reviewed and recent results related to charge carrier and exciton dynamics in organic thin films will be presented.[4pt] In collaboration with Whitney Shepherd, Mark Kendrick, Andrew Platt, Oregon State University; Marsha Loth and John Anthony, University of Kentucky.

  19. Electron energy loss spectroscopy in advanced materials

    SciTech Connect

    Zaluzec, N.J.

    1991-01-01

    The combination of a Transmission Electron Microscope (TEM) with an electron energy loss spectrometer (EELS) yields a powerful tool for the microcharacterization of materials. However, the application of this technique to advanced materials problems can only be fully appreciated when the information obtained using EELS is related to that obtained from other analytical spectroscopies. In this chapter, we briefly discuss the relative performance of X-ray, Auger and Photoelectron Spectroscopies with EELS pointing out the limitations and merits of each. This comparison is followed by examples of the application of EELS to investigations involving high {Tc} superconductors, artificial metallic superlattices, amorphous magnetic materials and the characterization of metallic hydride phases. 14 refs., 22 figs.

  20. Automotive applications for advanced composite materials

    NASA Technical Reports Server (NTRS)

    Deutsch, G. C.

    1978-01-01

    A description is presented of nonaerospace applications for advanced composite materials with special emphasis on the automotive applications. The automotive industry has to satisfy exacting requirements to reduce the average fuel consumption of cars. A feasible approach to accomplish this involves the development of composites cars with a total weight of 2400 pounds and a fuel consumption of 33 miles per gallon. In connection with this possibility, the automotive companies have started to look seriously at composite materials. The aerospace industry has over the past decade accumulated a considerable data base on composite materials and this is being made available to the nonaerospace sector. However, the automotive companies will place prime emphasis on low cost resins which lend themselves to rapid fabrication techniques.

  1. International Symposium on Advanced Materials (ISAM 2013)

    NASA Astrophysics Data System (ADS)

    2014-06-01

    This proceeding is a compilation of peer reviewed papers presented at the 13th International Symposium on Advanced Materials (ISAM 2013) held from September 23-27, 2013, at Islamabad, Pakistan. In my capacity as ISAM-2013 Secretary, I feel honoured that the symposium has ended on a positive note. The ever increasing changes and intricacies that characterize modern industry necessitate a growing demand for technical information on advanced materials. ISAM and other similar forums serve to fulfill this need. The five day deliberations of ISAM 2013, consisted of 19 technical sessions and 2 poster sessions. In all, 277 papers were presented, inclusive of 80 contributory, invited and oral presentations. The symposium also hosted panel discussions led by renowned scientists and eminent researchers from foreign as well as local institutes. The ultimate aim of this proceeding is to record in writing the new findings in the field of advanced materials. I hope that the technical data available in this publication proves valuable to young scientists and researchers working in this area of science. At the same time, I wish to acknowledge Institute of Physics (IOP) Publishing UK, for accepting the research papers from ISAM-2013 for publication in the IOP Conference Series: Materials Science and Engineering. The proceeding will be available on the IOP website as an online open access document. I am profoundly thankful to the Symposium Chairman for his steadfast support and valuable guidance without which ISAM 2013 could not have been the mega event that it turned out to be. My gratitude to all our distinguished participants, session chairs/co-chairs, and reviewers for their active role in the symposium. I appreciate the entire organizing committee for the zest and ardor with which each committee fulfilled its obligations to ISAM. Last yet not the least, my thankfulness goes to all our sponsors for wilfully financing the event. Dr. Sara Qaisar Symposium Secretary Further

  2. ASME Material Challenges for Advanced Reactor Concepts

    SciTech Connect

    Piyush Sabharwall; Ali Siahpush

    2013-07-01

    This study presents the material Challenges associated with Advanced Reactor Concept (ARC) such as the Advanced High Temperature Reactor (AHTR). ACR are the next generation concepts focusing on power production and providing thermal energy for industrial applications. The efficient transfer of energy for industrial applications depends on the ability to incorporate cost-effective heat exchangers between the nuclear heat transport system and industrial process heat transport system. The heat exchanger required for AHTR is subjected to a unique set of conditions that bring with them several design challenges not encountered in standard heat exchangers. The corrosive molten salts, especially at higher temperatures, require materials throughout the system to avoid corrosion, and adverse high-temperature effects such as creep. Given the very high steam generator pressure of the supercritical steam cycle, it is anticipated that water tube and molten salt shell steam generators heat exchanger will be used. In this paper, the ASME Section III and the American Society of Mechanical Engineers (ASME) Section VIII requirements (acceptance criteria) are discussed. Also, the ASME material acceptance criteria (ASME Section II, Part D) for high temperature environment are presented. Finally, lack of ASME acceptance criteria for thermal design and analysis are discussed.

  3. The recycling dilemma for advanced materials use: Automobile materials substitution

    SciTech Connect

    Field, F.R. III; Clark, J.P. )

    1991-01-01

    This paper discusses the difficulties associated with imposing recycling imperatives upon advanced materials development by examining the case of automotive materials substitution and its impacts upon the recyclability of the automobile. Parallels are drawn between today's issues, which focus upon the recyclability of the increasing polymeric fraction in automobile shredder fluff, and the junked automobile problem of the 1960's, when the problem of abandoned automobiles became a part of the environmental and legislative agenda in the US and overseas. In the 1960's, both the source and the resolution of the junk automobile problem arose through a confluence of technological and economic factors, rather than through any set of regulatory influences. The rise of electric arc furnace steelmaking and the development of the automobile shredder were sufficient to virtually eliminate the problem - so much so that today's problems are incorrectly viewed as novelties. Today's automobile recycling problem again derives from technological and economic factors, but regulatory influences have spurred some of them. While there are no lack of technological solutions to the problem of automobile shredder fluff, none of these solutions yet provides scrap processors with the kind of profit opportunity necessary to implement them. In some ways, it is implicit in advanced materials markets that there is little to no demand for recycled forms of these materials, and, in the absence of these markets, there are few reasons to expect that the solution to today's problems will be quite so neat.

  4. Advanced Bioinks for 3D Printing: A Materials Science Perspective.

    PubMed

    Chimene, David; Lennox, Kimberly K; Kaunas, Roland R; Gaharwar, Akhilesh K

    2016-06-01

    Advanced bioinks for 3D printing are rationally designed materials intended to improve the functionality of printed scaffolds outside the traditional paradigm of the "biofabrication window". While the biofabrication window paradigm necessitates compromise between suitability for fabrication and ability to accommodate encapsulated cells, recent developments in advanced bioinks have resulted in improved designs for a range of biofabrication platforms without this tradeoff. This has resulted in a new generation of bioinks with high print fidelity, shear-thinning characteristics, and crosslinked scaffolds with high mechanical strength, high cytocompatibility, and the ability to modulate cellular functions. In this review, we describe some of the promising strategies being pursued to achieve these goals, including multimaterial, interpenetrating network, nanocomposite, and supramolecular bioinks. We also provide an overview of current and emerging trends in advanced bioink synthesis and biofabrication, and evaluate the potential applications of these novel biomaterials to clinical use. PMID:27184494

  5. Advanced Technology Composite Fuselage - Materials and Processes

    NASA Technical Reports Server (NTRS)

    Scholz, D. B.; Dost, E. F.; Flynn, B. W.; Ilcewicz, L. B.; Nelson, K. M.; Sawicki, A. J.; Walker, T. H.; Lakes, R. S.

    1997-01-01

    The goal of Boeing's Advanced Technology Composite Aircraft Structures (ATCAS) program was to develop the technology required for cost and weight efficient use of composite materials in transport fuselage structure. This contractor report describes results of material and process selection, development, and characterization activities. Carbon fiber reinforced epoxy was chosen for fuselage skins and stiffening elements and for passenger and cargo floor structures. The automated fiber placement (AFP) process was selected for fabrication of monolithic and sandwich skin panels. Circumferential frames and window frames were braided and resin transfer molded (RTM'd). Pultrusion was selected for fabrication of floor beams and constant section stiffening elements. Drape forming was chosen for stringers and other stiffening elements. Significant development efforts were expended on the AFP, braiding, and RTM processes. Sandwich core materials and core edge close-out design concepts were evaluated. Autoclave cure processes were developed for stiffened skin and sandwich structures. The stiffness, strength, notch sensitivity, and bearing/bypass properties of fiber-placed skin materials and braided/RTM'd circumferential frame materials were characterized. The strength and durability of cocured and cobonded joints were evaluated. Impact damage resistance of stiffened skin and sandwich structures typical of fuselage panels was investigated. Fluid penetration and migration mechanisms for sandwich panels were studied.

  6. NIST Materials Properties Databases for Advanced Ceramics

    PubMed Central

    Munro, R. G.

    2001-01-01

    The NIST Ceramics Division maintains two databases on the physical, mechanical, thermal, and other properties of high temperature superconductors and structural ceramics. Crystallographic data are featured prominently among the physical property data and serve several important functions in the classification and evaluation of the property values. The scope of materials, properties, and data evaluation protocols are discussed for the two databases.

  7. Advanced Materials Laboratory User Test Planning Guide

    NASA Technical Reports Server (NTRS)

    Orndoff, Evelyne

    2012-01-01

    Test process, milestones and inputs are unknowns to first-time users of the Advanced Materials Laboratory. The User Test Planning Guide aids in establishing expectations for both NASA and non-NASA facility customers. The potential audience for this guide includes both internal and commercial spaceflight hardware/software developers. It is intended to assist their test engineering personnel in test planning and execution. Material covered includes a roadmap of the test process, roles and responsibilities of facility and user, major milestones, facility capabilities, and inputs required by the facility. Samples of deliverables, test article interfaces, and inputs necessary to define test scope, cost, and schedule are included as an appendix to the guide.

  8. Development of advanced composite ceramic tool material

    SciTech Connect

    Huang Chuanzhen; Ai Xing

    1996-08-01

    An advanced ceramic cutting tool material has been developed by means of silicon carbide whisker (SiCw) reinforcement and silicon carbide particle (SiCp) dispersion. The material has the advantage of high bending strength and fracture toughness. Compared with the mechanical properties of Al{sub 2}O{sub 3}/SiCp(AP), Al{sub 2}O{sub 3}/SiCw(JX-1), and Al{sub 2}O{sub 3}/SiCp/SiCw(JX-2-I), it confirms that JX-2-I composites have obvious additive effects of both reinforcing and toughening. The reinforcing and toughening mechanisms of JX-2-I composites were studied based on the analysis of thermal expansion mismatch and the observation of microstructure. The cutting performance of JX-2-I composites was investigated primarily.

  9. NREL Advances Spillover Materials for Hydrogen Storage (Fact Sheet)

    SciTech Connect

    Not Available

    2010-12-01

    This fact sheet describes NREL's accomplishments in advancing spillover materials for hydrogen storage and improving the reproducible synthesis, long-term durability, and material costs of hydrogen storage materials. Work was performed by NREL's Chemical and Materials Science Center.

  10. Advanced materials for radiation-cooled rockets

    NASA Astrophysics Data System (ADS)

    Reed, Brian; Biaglow, James; Schneider, Steven

    1993-11-01

    The most common material system currently used for low thrust, radiation-cooled rockets is a niobium alloy (C-103) with a fused silica coating (R-512A or R-512E) for oxidation protection. However, significant amounts of fuel film cooling are usually required to keep the material below its maximum operating temperature of 1370 C, degrading engine performance. Also the R-512 coating is subject to cracking and eventual spalling after repeated thermal cycling. A new class of high-temperature, oxidation-resistant materials are being developed for radiation-cooled rockets, with the thermal margin to reduce or eliminate fuel film cooling, while still exceeding the life of silicide-coated niobium. Rhenium coated with iridium is the most developed of these high-temperature materials. Efforts are on-going to develop 22 N, 62 N, and 440 N engines composed of these materials for apogee insertion, attitude control, and other functions. There is also a complimentary NASA and industry effort to determine the life limiting mechanisms and characterize the thermomechanical properties of these materials. Other material systems are also being studied which may offer more thermal margin and/or oxidation resistance, such as hafnium carbide/tantalum carbide matrix composites and ceramic oxide-coated iridium/rhenium chambers.

  11. Advanced materials for radiation-cooled rockets

    NASA Technical Reports Server (NTRS)

    Reed, Brian; Biaglow, James; Schneider, Steven

    1993-01-01

    The most common material system currently used for low thrust, radiation-cooled rockets is a niobium alloy (C-103) with a fused silica coating (R-512A or R-512E) for oxidation protection. However, significant amounts of fuel film cooling are usually required to keep the material below its maximum operating temperature of 1370 C, degrading engine performance. Also the R-512 coating is subject to cracking and eventual spalling after repeated thermal cycling. A new class of high-temperature, oxidation-resistant materials are being developed for radiation-cooled rockets, with the thermal margin to reduce or eliminate fuel film cooling, while still exceeding the life of silicide-coated niobium. Rhenium coated with iridium is the most developed of these high-temperature materials. Efforts are on-going to develop 22 N, 62 N, and 440 N engines composed of these materials for apogee insertion, attitude control, and other functions. There is also a complimentary NASA and industry effort to determine the life limiting mechanisms and characterize the thermomechanical properties of these materials. Other material systems are also being studied which may offer more thermal margin and/or oxidation resistance, such as hafnium carbide/tantalum carbide matrix composites and ceramic oxide-coated iridium/rhenium chambers.

  12. Advance Abrasion Resistant Materials for Mining

    SciTech Connect

    Mackiewicz-Ludtka, G.

    2004-06-01

    The high-density infrared (HDI) transient-liquid coating (TLC) process was successfully developed and demonstrated excellent, enhanced (5 times higher than the current material and process) wear performance for the selected functionally graded material (FGM) coatings under laboratory simulated, in-service conditions. The mating steel component exhibited a wear rate improvement of approximately one and a half (1.5) times. After 8000 cycles of. wear testing, the full-scale component testing demonstrated that the coating integrity was still excellent. Little or no spalling was observed to occur.

  13. ADVANCED ABRASION RESISTANT MATERIALS FOR MINING

    SciTech Connect

    Ludtka, G.M.

    2004-04-08

    The high-density infrared (HDI) transient-liquid coating (TLC) process was successfully developed and demonstrated excellent, enhanced (5 times higher than the current material and process) wear performance for the selected functionally graded material (FGM) coatings under laboratory simulated, in-service conditions. The mating steel component exhibited a wear rate improvement of approximately one and a half (1.5) times. After 8000 cycles of wear testing, the full-scale component testing demonstrated that the coating integrity was still excellent. Little or no spalling was observed to occur.

  14. Materials for advanced ultrasupercritical steam turbines

    SciTech Connect

    Purgert, Robert; Shingledecker, John; Saha, Deepak; Thangirala, Mani; Booras, George; Powers, John; Riley, Colin; Hendrix, Howard

    2015-12-01

    The U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) have sponsored a project aimed at identifying, evaluating, and qualifying the materials needed for the construction of the critical components of coal-fired power plants capable of operating at much higher efficiencies than the current generation of supercritical plants. This increased efficiency is expected to be achieved principally through the use of advanced ultrasupercritical (A-USC) steam conditions. A limiting factor in this can be the materials of construction for boilers and for steam turbines. The overall project goal is to assess/develop materials technology that will enable achieving turbine throttle steam conditions of 760°C (1400°F)/35MPa (5000 psi). This final technical report covers the research completed by the General Electric Company (GE) and Electric Power Research Institute (EPRI), with support from Oak Ridge National Laboratory (ORNL) and the National Energy Technology Laboratory (NETL) – Albany Research Center, to develop the A-USC steam turbine materials technology to meet the overall project goals. Specifically, this report summarizes the industrial scale-up and materials property database development for non-welded rotors (disc forgings), buckets (blades), bolting, castings (needed for casing and valve bodies), casting weld repair, and casting to pipe welding. Additionally, the report provides an engineering and economic assessment of an A-USC power plant without and with partial carbon capture and storage. This research project successfully demonstrated the materials technology at a sufficient scale and with corresponding materials property data to enable the design of an A-USC steam turbine. The key accomplishments included the development of a triple-melt and forged Haynes 282 disc for bolted rotor construction, long-term property development for Nimonic 105 for blading and bolting, successful scale-up of Haynes 282 and Nimonic 263 castings using

  15. Polymers as advanced materials for desiccant applications

    SciTech Connect

    Czanderna, A.W.

    1990-12-01

    This research is concerned with solid materials used as desiccants for desiccant cooling systems (DCSs) that process water vapor in an atmosphere to produce cooling. Background information includes an introduction to DCSs and the role of the desiccant as a system component. The water vapor sorption performance criteria used for screening the modified polymers prepared include the water sorption capacity from 5% to 80% relative humidity (R.H.), isotherm shape, and rate of adsorption and desorption. Measurements are presented for the sorption performance of modified polymeric advanced desiccant materials with the quartz crystal microbalance. Isotherms of polystyrene sulfonic acid (PSSA) taken over a 5-month period show that the material has a dramatic loss in capacity and that the isotherm shape is time dependent. The adsorption and desorption kinetics for PSSA and all the ionic salts of it studied are easily fast enough for commercial DCS applications with a wheel rotation speed of 6 min per revolution. Future activities for the project are addressed, and a 5-year summary of the project is included as Appendix A. 34 refs., 20 figs., 3 tabs.

  16. Recent Advances in Two-Dimensional Materials Beyond Graphene

    SciTech Connect

    Meunier, Vincent; Sumpter, Bobby G.; Terrones Maldonado, Mauricio; Terrones Maldonado, Humberto; Liang, Liangbo; Cooper, Valentino R.; Bhimanapati, Ganesh; Lin, Zhong; Jung, Yeongwoong; Cha, Judy; Das, Saptarshi; Xiao, Di; Son, Youngwoo; Strano, Michael; Louie, Steven G.; Ringe, Emilie; Xia, Fengnian; Wang, Yeliang; Akinwande, Deji; Zhu, Jun; Schuller, John; Schaak, Raymond; Robinson, Joshua A

    2015-11-06

    The isolation of graphene in 2004 by peeling apart the atomically-thin sheets that comprise graphite was a defining moment for the birth of a field: Two-dimensional (2D) materials. In recent years, there has been a rapidly increasing number of papers focusing on non-graphene layered materials, including transition-metal dichalcogenides (TMDs), because of the new properties and applications that emerge upon 2D confinement. Here we review significant recent advances and important new developments in 2D materials beyond graphene . We provide insight into the theoretical modeling and understanding of the van der Waals forces that hold together the 2D layers in bulk solids, as well as their excitonic properties and growth morphologies. Additionally, we highlight recent breakthroughs in TMD synthesis and characterization and discuss the newest families of 2D materials, including monoelement 2D materials (i.e., silicene, phosphorene, etc.) and transition metal carbide- and carbon nitride-based MXenes. We then discuss the doping and functionalization of 2D materials beyond graphene, which enable device applications, followed by advances in electronic, optoelectronic, and magnetic devices and theory. Finally, we provide perspectives on the future of 2D materials beyond graphene.

  17. Recent Advances in Two-Dimensional Materials Beyond Graphene

    DOE PAGESBeta

    Meunier, Vincent; Sumpter, Bobby G.; Terrones Maldonado, Mauricio; Terrones Maldonado, Humberto; Liang, Liangbo; Cooper, Valentino R.; Bhimanapati, Ganesh; Lin, Zhong; Jung, Yeongwoong; Cha, Judy; et al

    2015-11-06

    The isolation of graphene in 2004 by peeling apart the atomically-thin sheets that comprise graphite was a defining moment for the birth of a field: Two-dimensional (2D) materials. In recent years, there has been a rapidly increasing number of papers focusing on non-graphene layered materials, including transition-metal dichalcogenides (TMDs), because of the new properties and applications that emerge upon 2D confinement. Here we review significant recent advances and important new developments in 2D materials beyond graphene . We provide insight into the theoretical modeling and understanding of the van der Waals forces that hold together the 2D layers in bulkmore » solids, as well as their excitonic properties and growth morphologies. Additionally, we highlight recent breakthroughs in TMD synthesis and characterization and discuss the newest families of 2D materials, including monoelement 2D materials (i.e., silicene, phosphorene, etc.) and transition metal carbide- and carbon nitride-based MXenes. We then discuss the doping and functionalization of 2D materials beyond graphene, which enable device applications, followed by advances in electronic, optoelectronic, and magnetic devices and theory. Finally, we provide perspectives on the future of 2D materials beyond graphene.« less

  18. Recent Advances in Two-Dimensional Materials beyond Graphene.

    PubMed

    Bhimanapati, Ganesh R; Lin, Zhong; Meunier, Vincent; Jung, Yeonwoong; Cha, Judy; Das, Saptarshi; Xiao, Di; Son, Youngwoo; Strano, Michael S; Cooper, Valentino R; Liang, Liangbo; Louie, Steven G; Ringe, Emilie; Zhou, Wu; Kim, Steve S; Naik, Rajesh R; Sumpter, Bobby G; Terrones, Humberto; Xia, Fengnian; Wang, Yeliang; Zhu, Jun; Akinwande, Deji; Alem, Nasim; Schuller, Jon A; Schaak, Raymond E; Terrones, Mauricio; Robinson, Joshua A

    2015-12-22

    The isolation of graphene in 2004 from graphite was a defining moment for the "birth" of a field: two-dimensional (2D) materials. In recent years, there has been a rapidly increasing number of papers focusing on non-graphene layered materials, including transition-metal dichalcogenides (TMDs), because of the new properties and applications that emerge upon 2D confinement. Here, we review significant recent advances and important new developments in 2D materials "beyond graphene". We provide insight into the theoretical modeling and understanding of the van der Waals (vdW) forces that hold together the 2D layers in bulk solids, as well as their excitonic properties and growth morphologies. Additionally, we highlight recent breakthroughs in TMD synthesis and characterization and discuss the newest families of 2D materials, including monoelement 2D materials (i.e., silicene, phosphorene, etc.) and transition metal carbide- and carbon nitride-based MXenes. We then discuss the doping and functionalization of 2D materials beyond graphene that enable device applications, followed by advances in electronic, optoelectronic, and magnetic devices and theory. Finally, we provide perspectives on the future of 2D materials beyond graphene. PMID:26544756

  19. Thermal fatigue durability for advanced propulsion materials

    NASA Technical Reports Server (NTRS)

    Halford, Gary R.

    1989-01-01

    A review is presented of thermal and thermomechanical fatigue (TMF) crack initiation life prediction and cyclic constitutive modeling efforts sponsored recently by the NASA Lewis Research Center in support of advanced aeronautical propulsion research. A brief description is provided of the more significant material durability models that were created to describe TMF fatigue resistance of both isotropic and anisotropic superalloys, with and without oxidation resistant coatings. The two most significant crack initiation models are the cyclic damage accumulation model and the total strain version of strainrange partitioning. Unified viscoplastic cyclic constitutive models are also described. A troika of industry, university, and government research organizations contributed to the generation of these analytic models. Based upon current capabilities and established requirements, an attempt is made to project which TMF research activities most likely will impact future generation propulsion systems.

  20. Advanced Pattern Material for Investment Casting Applications

    SciTech Connect

    F. Douglas Neece Neil Chaudhry

    2006-02-08

    Cleveland Tool and Machine (CTM) of Cleveland, Ohio in conjunction with Harrington Product Development Center (HPDC) of Cincinnati, Ohio have developed an advanced, dimensionally accurate, temperature-stable, energy-efficient and cost-effective material and process to manufacture patterns for the investment casting industry. In the proposed technology, FOPAT (aFOam PATtern material) has been developed which is especially compatible with the investment casting process and offers the following advantages: increased dimensional accuracy; increased temperature stability; lower cost per pattern; less energy consumption per pattern; decreased cost of pattern making equipment; decreased tooling cost; increased casting yield. The present method for investment casting is "the lost wax" process, which is exactly that, the use of wax as a pattern material, which is then melted out or "lost" from the ceramic shell. The molten metal is then poured into the ceramic shell to produce a metal casting. This process goes back thousands of years and while there have been improvements in the wax and processing technology, the material is basically the same, wax. The proposed technology is based upon an established industrial process of "Reaction Injection Molding" (RIM) where two components react when mixed and then "molded" to form a part. The proposed technology has been modified and improved with the needs of investment casting in mind. A proprietary mix of components has been formulated which react and expand to form a foam-like product. The result is an investment casting pattern with smooth surface finish and excellent dimensional predictability along with the other key benefits listed above.

  1. Advanced materials for thermal protection system

    NASA Astrophysics Data System (ADS)

    Heng, Sangvavann; Sherman, Andrew J.

    1996-03-01

    Reticulated open-cell ceramic foams (both vitreous carbon and silicon carbide) and ceramic composites (SiC-based, both monolithic and fiber-reinforced) were evaluated as candidate materials for use in a heat shield sandwich panel design as an advanced thermal protection system (TPS) for unmanned single-use hypersonic reentry vehicles. These materials were fabricated by chemical vapor deposition/infiltration (CVD/CVI) and evaluated extensively for their mechanical, thermal, and erosion/ablation performance. In the TPS, the ceramic foams were used as a structural core providing thermal insulation and mechanical load distribution, while the ceramic composites were used as facesheets providing resistance to aerodynamic, shear, and erosive forces. Tensile, compressive, and shear strength, elastic and shear modulus, fracture toughness, Poisson's ratio, and thermal conductivity were measured for the ceramic foams, while arcjet testing was conducted on the ceramic composites at heat flux levels up to 5.90 MW/m2 (520 Btu/ft2ṡsec). Two prototype test articles were fabricated and subjected to arcjet testing at heat flux levels of 1.70-3.40 MW/m2 (150-300 Btu/ft2ṡsec) under simulated reentry trajectories.

  2. Indentation Methods in Advanced Materials Research Introduction

    SciTech Connect

    Pharr, George Mathews; Cheng, Yang-Tse; Hutchings, Ian; Sakai, Mototsugu; Moody, Neville; Sundararajan, G.; Swain, Michael V.

    2009-01-01

    Since its commercialization early in the 20th century, indentation testing has played a key role in the development of new materials and understanding their mechanical behavior. Progr3ess in the field has relied on a close marriage between research in the mechanical behavior of materials and contact mechanics. The seminal work of Hertz laid the foundations for bringing these two together, with his contributions still widely utilized today in examining elastic behavior and the physics of fracture. Later, the pioneering work of Tabor, as published in his classic text 'The Hardness of Metals', exapdned this understanding to address the complexities of plasticity. Enormous progress in the field has been achieved in the last decade, made possible both by advances in instrumentation, for example, load and depth-sensing indentation and scanning electron microscopy (SEM) and transmission electron microscopy (TEM) based in situ testing, as well as improved modeling capabilities that use computationally intensive techniques such as finite element analysis and molecular dynamics simulation. The purpose of this special focus issue is to present recent state of the art developments in the field.

  3. Supramolecular polymer adhesives: advanced materials inspired by nature.

    PubMed

    Heinzmann, Christian; Weder, Christoph; de Espinosa, Lucas Montero

    2016-01-21

    Due to their dynamic, stimuli-responsive nature, non-covalent interactions represent versatile design elements that can be found in nature in many molecular processes or materials, where adaptive behavior or reversible connectivity is required. Examples include molecular recognition processes, which trigger biological responses or cell-adhesion to surfaces, and a broad range of animal secreted adhesives with environment-dependent properties. Such advanced functionalities have inspired researchers to employ similar design approaches for the development of synthetic polymers with stimuli-responsive properties. The utilization of non-covalent interactions for the design of adhesives with advanced functionalities such as stimuli responsiveness, bonding and debonding on demand capability, surface selectivity or recyclability is a rapidly emerging subset of this field, which is summarized in this review. PMID:26203784

  4. Advanced Materials in Support of EERE Needs to Advance Clean Energy Technologies Program Implementation

    SciTech Connect

    Liby, Alan L; Rogers, Hiram

    2013-10-01

    The goal of this activity was to carry out program implementation and technical projects in support of the ARRA-funded Advanced Materials in Support of EERE Needs to Advance Clean Energy Technologies Program of the DOE Advanced Manufacturing Office (AMO) (formerly the Industrial Technologies Program (ITP)). The work was organized into eight projects in four materials areas: strategic materials, structural materials, energy storage and production materials, and advanced/field/transient processing. Strategic materials included work on titanium, magnesium and carbon fiber. Structural materials included work on alumina forming austentic (AFA) and CF8C-Plus steels. The advanced batteries and production materials projects included work on advanced batteries and photovoltaic devices. Advanced/field/transient processing included work on magnetic field processing. Details of the work in the eight projects are available in the project final reports which have been previously submitted.

  5. Abrasive wear of advanced structural materials

    NASA Astrophysics Data System (ADS)

    Lee, Gun-Young

    Wear of advanced structural materials, namely composites and ceramics, in abrasion has been examined in the present study. A simple physically-based model for the abrasive wear of composite materials is presented based on the mechanics and mechanisms associated with sliding wear in soft (ductile) matrix composites containing hard (brittle) reinforcement particles. The model is based on the assumption that any portion of the reinforcement that is removed as wear debris cannot contribute to the wear resistance of the matrix material. The size of this non-contributing portion of reinforcement is estimated by modeling three primary wear mechanisms, specifically plowing, cracking at the matrix/reinforcement interface or in the reinforcement, and particle removal. Critical variables describing the role of the reinforcement, such as the relative size, fracture toughness, and the nature of the matrix/reinforcement interface, are characterized by a single contribution coefficient, C. Predictions are compared with the results of experimental two-body (pin-on-drum) abrasive wear tests performed on a model aluminum particulate-reinforced epoxy-matrix composite material. In addition, the effects of post heat-treatment on the wear behavior of toughened silicon carbide (ABC-SiC) are investigated by characterizing the role of the microstructures introduced during the post annealing processes. When the annealing temperature is above 1300°C, an aluminum rich secondary phase (nano-precipitate) forms and grows inside the SiC grains. This toughened silicon carbide (ABC-SiC), annealed at temperatures ranging from 0 to 1600°C, is subjected to two- and three-body abrasions with different sizes of abrasives (3˜70 mum). The test results exhibit that the effect of nano-precipitates on wear resistance of post-annealed ABC-SiC is restricted to the abrasion with fine abrasives (3 mum), since nano-precipitates, in the range from 4 nm at 1300°C to 25 nm at 1600°C, are comparable in dimension

  6. Advanced High-Temperature Engine Materials Technology Progresses

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The objective of the Advanced High Temperature Engine Materials Technology Program (HITEMP) at the NASA Lewis Research Center is to generate technology for advanced materials and structural analysis that will increase fuel economy, improve reliability, extend life, and reduce operating costs for 21st century civil propulsion systems. The primary focus is on fan and compressor materials (polymer-matrix composites - PMC's), compressor and turbine materials (superalloys, and metal-matrix and intermetallic-matrix composites - MMC's and IMC's), and turbine materials (ceramic-matrix composites - CMC's). These advanced materials are being developed in-house by Lewis researchers and on grants and contracts.

  7. Studies of noise transmission in advanced composite material structures

    NASA Technical Reports Server (NTRS)

    Roussos, L. A.; Mcgary, M. C.; Powell, C. A.

    1983-01-01

    Noise characteristics of advanced composite material fuselages were discussed from the standpoints of applicable research programs and noise transmission theory. Experimental verification of the theory was also included.

  8. Functionally graded materials for thermal barrier coatings in advanced gas turbine systems research. Semi-annual report, May 1--December 31, 1996

    SciTech Connect

    1997-08-01

    A combination of two new production methods, reaction-bonded metal oxide (RBMO) and electrochemical processing, have been utilized to create a functionally graded thermal barrier coating. Electrochemical processing, which includes both electrodeposition (EDEP) and electrophoretic deposition (EPD), has been used to deposit both the metallic and ceramic layers of the coating. EPD has been used to deposit the RBMO precursor powders, which exhibit the dual properties of both a metal and ceramic due to its composite nature. A summary of the FGM production methods and resulting characterization of the produced coatings for the eleventh and twelfth quarters (5/96--12/96), as well as a project summary, are outlined in this final report.

  9. Crashworthiness analysis using advanced material models in DYNA3D

    SciTech Connect

    Logan, R.W.; Burger, M.J.; McMichael, L.D.; Parkinson, R.D.

    1993-10-22

    As part of an electric vehicle consortium, LLNL and Kaiser Aluminum are conducting experimental and numerical studies on crashworthy aluminum spaceframe designs. They have jointly explored the effect of heat treat on crush behavior and duplicated the experimental behavior with finite-element simulations. The major technical contributions to the state of the art in numerical simulation arise from the development and use of advanced material model descriptions for LLNL`s DYNA3D code. Constitutive model enhancements in both flow and failure have been employed for conventional materials such as low-carbon steels, and also for lighter weight materials such as aluminum and fiber composites being considered for future vehicles. The constitutive model enhancements are developed as extensions from LLNL`s work in anisotropic flow and multiaxial failure modeling. Analysis quality as a function of level of simplification of material behavior and mesh is explored, as well as the penalty in computation cost that must be paid for using more complex models and meshes. The lightweight material modeling technology is being used at the vehicle component level to explore the safety implications of small neighborhood electric vehicles manufactured almost exclusively from these materials.

  10. Analysis of an advanced technology subsonic turbofan incorporating revolutionary materials

    NASA Technical Reports Server (NTRS)

    Knip, Gerald, Jr.

    1987-01-01

    Successful implementation of revolutionary composite materials in an advanced turbofan offers the possibility of further improvements in engine performance and thrust-to-weight ratio relative to current metallic materials. The present analysis determines the approximate engine cycle and configuration for an early 21st century subsonic turbofan incorporating all composite materials. The advanced engine is evaluated relative to a current technology baseline engine in terms of its potential fuel savings for an intercontinental quadjet having a design range of 5500 nmi and a payload of 500 passengers. The resultant near optimum, uncooled, two-spool, advanced engine has an overall pressure ratio of 87, a bypass ratio of 18, a geared fan, and a turbine rotor inlet temperature of 3085 R. Improvements result in a 33-percent fuel saving for the specified misssion. Various advanced composite materials are used throughout the engine. For example, advanced polymer composite materials are used for the fan and the low pressure compressor (LPC).

  11. Demonstration Advanced Avionics System (DAAS) function description

    NASA Technical Reports Server (NTRS)

    Bailey, A. J.; Bailey, D. G.; Gaabo, R. J.; Lahn, T. G.; Larson, J. C.; Peterson, E. M.; Schuck, J. W.; Rodgers, D. L.; Wroblewski, K. A.

    1982-01-01

    The Demonstration Advanced Avionics System, DAAS, is an integrated avionics system utilizing microprocessor technologies, data busing, and shared displays for demonstrating the potential of these technologies in improving the safety and utility of general aviation operations in the late 1980's and beyond. Major hardware elements of the DAAS include a functionally distributed microcomputer complex, an integrated data control center, an electronic horizontal situation indicator, and a radio adaptor unit. All processing and display resources are interconnected by an IEEE-488 bus in order to enhance the overall system effectiveness, reliability, modularity and maintainability. A detail description of the DAAS architecture, the DAAS hardware, and the DAAS functions is presented. The system is designed for installation and flight test in a NASA Cessna 402-B aircraft.

  12. New Advances in SuperConducting Materials

    ScienceCinema

    None

    2014-08-12

    Superconducting materials will transform the world's electrical infrastructure, saving billions of dollars once the technical details and installation are in place. At Los Alamos National Laboratory, new materials science concepts are bringing this essential technology closer to widespread industrial use.

  13. Development of advanced thermoelectric materials, phase A

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Work performed on the chemical system characterized by chrome sulfide, chrome selenide, lanthanum selenide, and lanthanum sulfide is described. Most materials within the chemical systems possess the requisites for attractive thermoelectric materials. The preparation of the alloys is discussed. Graphs show the Seebeck coefficient, electrical resistivity, and thermal conductivity of various materials within the chemical systems. The results of selected doping are included.

  14. Microstructural and mechanical characterization of laser deposited advanced materials

    NASA Astrophysics Data System (ADS)

    Sistla, Harihar Rakshit

    Additive manufacturing in the form of laser deposition is a unique way to manufacture near net shape metallic components from advanced materials. Rapid solidification facilitates the extension of solid solubility, compositional flexibility and decrease in micro-segregation in the melt among other advantages. The current work investigates the employment of laser deposition to fabricate the following: 1. Functionally gradient materials: This allows grading dissimilar materials compositionally to tailor specific properties of both these materials into a single component. Specific compositions of the candidate materials (SS 316, Inconel 625 and Ti64) were blended and deposited to study the brittle intermetallics reported in these systems. 2. High entropy alloys: These are multi- component alloys with equiatomic compositions of 5 or more elements. The ratio of Al to Ni was decreased to observe the transition of solid solution from a BCC to an FCC crystal structure in the AlFeCoCrNi system. 3. Structurally amorphous alloys: Zr-based metallic glasses have been reported to have high glass forming ability. These alloys have been laser deposited so as to rapidly cool them from the melt into an amorphous state. Microstructural analysis and X-ray diffraction were used to study the phase formation, and hardness was measured to estimate the mechanical properties.

  15. Advanced materials for solid oxide fuel cells

    SciTech Connect

    Armstrong, T.R.; Stevenson, J.

    1995-08-01

    The purpose of this research is to improve the properties of the current state-of-the-art materials used for solid oxide fuel cells (SOFCs). The objectives are to: (1) develop materials based on modifications of the state-of-the-art materials; (2) minimize or eliminate stability problems in the cathode, anode, and interconnect; (3) Electrochemically evaluate (in reproducible and controlled laboratory tests) the current state-of-the-art air electrode materials and cathode/electrolyte interfacial properties; (4) Develop accelerated electrochemical test methods to evaluate the performance of SOFCs under controlled and reproducible conditions; and (5) Develop and test materials for use in low-temperature SOFCs. The goal is to modify and improve the current state-of-the-art materials and minimize the total number of cations in each material to avoid negative effects on the materials properties. Materials to reduce potential deleterious interactions, (3) improve thermal, electrical, and electrochemical properties, (4) develop methods to synthesize both state-of-the-art and alternative materials for the simultaneous fabricatoin and consolidation in air of the interconnections and electrodes with the solid electrolyte, and (5) understand electrochemical reactions at materials interfaces and the effects of component composition and processing on those reactions.

  16. Advancing safer alternatives through functional substitution.

    PubMed

    Tickner, Joel A; Schifano, Jessica N; Blake, Ann; Rudisill, Catherine; Mulvihill, Martin J

    2015-01-20

    To achieve the ultimate goal of sustainable chemicals management policy–the transition to safer chemicals, materials, products, and processes–current chemicals management approaches could benefit from a broader perspective. Starting with considerations of function, rather than characterizing and managing risks associated with a particular chemical, may provide a different, solutions-oriented lens to reduce risk associated with the uses of chemicals. It may also offer an efficient means, complementing existing tools, to reorient chemicals management approaches from time-intensive risk assessment and risk management based on single chemicals to comparative evaluation of the best options to fulfill a specific function. This article describes a functional approach to chemicals management we call “functional substitution” that encourages decision-makers to look beyond chemical by chemical substitution to find a range of alternatives to meet product performance. We define functional substitution, outline a rationale for greater use of this concept when considering risks posed by uses of chemicals, and provide examples of how functional approaches have been applied toward the identification of alternatives. We also discuss next steps for implementing functional substitution in chemical assessment and policy development. PMID:25517452

  17. Materials Challenges for Advanced Combustion and Gasification Fossil Energy Systems

    NASA Astrophysics Data System (ADS)

    Sridhar, S.; Rozzelle, P.; Morreale, B.; Alman, D.

    2011-04-01

    This special section of Metallurgical and Materials Transactions is devoted to materials challenges associated with coal based energy conversion systems. The purpose of this introductory article is to provide a brief outline to the challenges associated with advanced combustion and advanced gasification, which has the potential of providing clean, affordable electricity by improving process efficiency and implementing carbon capture and sequestration. Affordable materials that can meet the demanding performance requirements will be a key enabling technology for these systems.

  18. New Advance in SuperConducting Materials

    ScienceCinema

    None

    2010-01-08

    Superconducting materials will transform the world's electrical infrastructure, saving billions of dollars once the technical details and installation are in place. At Los Alamos National Laborator...  

  19. Advanced materials for space nuclear power systems

    NASA Technical Reports Server (NTRS)

    Titran, Robert H.; Grobstein, Toni L.; Ellis, David L.

    1991-01-01

    The overall philosophy of the research was to develop and characterize new high temperature power conversion and radiator materials and to provide spacecraft designers with material selection options and design information. Research on three candidate materials (carbide strengthened niobium alloy PWC-11 for fuel cladding, graphite fiber reinforced copper matrix composites for heat rejection fins, and tungsten fiber reinforced niobium matrix composites for fuel containment and structural supports) considered for space power system applications is discussed. Each of these types of materials offers unique advantages for space power applications.

  20. Advanced materials for space nuclear power systems

    NASA Technical Reports Server (NTRS)

    Titran, Robert H.; Grobstein, Toni L.; Ellis, David L.

    1991-01-01

    The overall philosophy of the research was to develop and characterize new high temperature power conversion and radiator materials and to provide spacecraft designers with material selection options and design information. Research on three candidate materials (carbide strengthened niobium alloy PWC-11 for fuel cladding, graphite fiber reinforced copper matrix composites for heat rejection fins, and tungsten fiber reinforced niobium matrix composites for fuel containment and structural supports considered for space power system applications is discussed. Each of these types of materials offers unique advantages for space power applications.

  1. New Advance in SuperConducting Materials

    SciTech Connect

    2009-03-02

    Superconducting materials will transform the world's electrical infrastructure, saving billions of dollars once the technical details and installation are in place. At Los Alamos National Laborator...  

  2. Numerical Forming Simulations and Optimisation in Advanced Materials

    NASA Astrophysics Data System (ADS)

    Huétink, J.; van den Boogaard, A. H.; Geijselears, H. J. M.; Meinders, T.

    2007-05-01

    With the introduction of new materials as high strength steels, metastable steels and fibre reinforced composites, the need for advanced physically valid constitutive models arises. In finite deformation problems constitutive relations are commonly formulated in terms the Cauchy stress as a function of the elastic Finger tensor and an objective rate of the Cauchy stress as a function of the rate of deformation tensor. For isotropic materials models this is rather straightforward, but for anisotropic material models, including elastic anisotropy as well as plastic anisotropy, this may lead to confusing formulations. It will be shown that it is more convenient to define the constitutive relations in terms of invariant tensors referred to the deformed metric. Experimental results are presented that show new combinations of strain rate and strain path sensitivity. An adaptive through- thickness integration scheme for plate elements is developed, which improves the accuracy of spring back prediction at minimal costs. A procedure is described to automatically compensate the CAD tool shape numerically to obtain the desired product shape. Forming processes need to be optimized for cost saving and product improvement. Until recently, a trial-and-error process in the factory primarily did this optimization. An optimisation strategy is proposed that assists an engineer to model an optimization problem that suits his needs, including an efficient algorithm for solving the problem.

  3. Progress in advanced high temperature materials technology

    NASA Technical Reports Server (NTRS)

    Freche, J. C.; Ault, G. M.

    1976-01-01

    Significant progress has recently been made in many high temperature material categories pertinent to such applications by the industrial community. These include metal matrix composites, superalloys, directionally solidified eutectics, coatings, and ceramics. Each of these material categories is reviewed and the current state-of-the-art identified, including some assessment, when appropriate, of progress, problems, and future directions.

  4. Cladding and Structural Materials for Advanced Nuclear Energy Systems

    SciTech Connect

    Was, G S; Allen, T R; Ila, D; C,; Levi,; Morgan, D; Motta, A; Wang, L; Wirth, B

    2011-06-30

    The goal of this consortium is to address key materials issues in the most promising advanced reactor concepts that have yet to be resolved or that are beyond the existing experience base of dose or burnup. The research program consists of three major thrusts: 1) high-dose radiation stability of advanced fast reactor fuel cladding alloys, 2) irradiation creep at high temperature, and 3) innovative cladding concepts embodying functionally-graded barrier materials. This NERI-Consortium final report represents the collective efforts of a large number of individuals over a period of three and a half years and included 9 PIs, 4 scientists, 3 post-docs and 12 students from the seven participating institutions and 8 partners from 5 national laboratories and 3 industrial institutions (see table). University participants met semi-annually and participants and partners met annually for meetings lasting 2-3 days and designed to disseminate and discuss results, update partners, address outstanding issues and maintain focus and direction toward achieving the objectives of the program. The participants felt that this was a highly successful program to address broader issues that can only be done by the assembly of a range of talent and capabilities at a more substantial funding level than the traditional NERI or NEUP grant. As evidence of the success, this group, collectively, has published 20 articles in archival journals and made 57 presentations at international conferences on the results of this consortium.

  5. Advances in functional electrical stimulation (FES).

    PubMed

    Popović, Dejan B

    2014-12-01

    This review discusses the advancements that are needed to enhance the effects of electrical stimulation for restoring or assisting movement in humans with an injury/disease of the central nervous system. A complex model of the effects of electrical stimulation of peripheral systems is presented. The model indicates that both the motor and sensory systems are activated by electrical stimulation. We propose that a hierarchical hybrid controller may be suitable for functional electrical stimulation (FES) because this type of controller acts as a structural mimetic of its biological counterpart. Specific attention is given to the neural systems at the periphery with respect to the required electrodes and stimulators. Furthermore, we note that FES with surface electrodes is preferred for the therapy, although there is a definite advantage associated with implantable technology for life-long use. The last section of the review discusses the potential need to combine FES and robotic systems to provide assistance in some cases. PMID:25287528

  6. AEGIS - Advanced Multi-Function Array Radar

    NASA Astrophysics Data System (ADS)

    Phillips, C. C.

    1981-12-01

    The AMFAR (Advanced Multi-Function Array Radar), a radar system technology developed in the late 1960s, has demonstrated automatic detection and tracking of all air targets plus inherent resistance to natural and man-made clutter with computer control of the radar. The major elements of the AMFAR - a high-power radar frequency transmitter, a phased-array antenna, a signal processor system, a computer control system, and an automated test system - are described in detail. The capabilities of the radar are demonstrated in a series of pictures showing processing steps to provide automatic target detection and track in both ground clutter zones and rain clutter. The success of AMFAR laid the foundation of Radar System AN/SPY-1A, the Weapon Control Radar System now being produced as a major element of the AEGIS Weapon System for the U.S. Navy guided missile cruiser Ticonderoga.

  7. Challenge to advanced materials processing with lasers in Japan

    NASA Astrophysics Data System (ADS)

    Miyamoto, Isamu

    2003-02-01

    Japan is one of the most advanced countries in manufacturing technology, and lasers have been playing an important role for advancement of manufacturing technology in a variety of industrial fields. Contribution of laser materials processing to Japanese industry is significant for both macroprocessing and microprocessing. The present paper describes recent trend and topics of industrial applications in terms of the hardware and the software to show how Japanese industry challenges to advanced materials processing using lasers, and national products related to laser materials processing are also briefly introduced.

  8. Advanced Materials and Cell Components for NASA's Exploration Missions

    NASA Technical Reports Server (NTRS)

    Reid, Concha M.

    2009-01-01

    This is an introductory paper for the focused session "Advanced Materials and Cell Components for NASA's Exploration Missions". This session will concentrate on electrochemical advances in materials and components that have been achieved through efforts sponsored under NASA's Exploration Systems Mission Directorate (ESMD). This paper will discuss the performance goals for components and for High Energy and Ultra High Energy cells, advanced lithium-ion cells that will offer a combination of higher specific energy and improved safety over state-of-the-art. Papers in this session will span a broad range of materials and components that are under development to enable these cell development efforts.

  9. Advanced lubrication systems and materials. Final report

    SciTech Connect

    Hsu, S.

    1998-05-07

    This report described the work conducted at the National Institute of Standards and Technology under an interagency agreement signed in September 1992 between DOE and NIST for 5 years. The interagency agreement envisions continual funding from DOE to support the development of fuel efficient, low emission engine technologies in terms of lubrication, friction, and wear control encountered in the development of advanced transportation technologies. However, in 1994, the DOE office of transportation technologies was reorganized and the tribology program was dissolved. The work at NIST therefore continued at a low level without further funding from DOE. The work continued to support transportation technologies in the development of fuel efficient, low emission engine development. Under this program, significant progress has been made in advancing the state of the art of lubrication technology for advanced engine research and development. Some of the highlights are: (1) developed an advanced high temperature liquid lubricant capable of sustaining high temperatures in a prototype heat engine; (2) developed a novel liquid lubricant which potentially could lower the emission of heavy duty diesel engines; (3) developed lubricant chemistries for ceramics used in the heat engines; (4) developed application maps for ceramic lubricant chemistry combinations for design purpose; and (5) developed novel test methods to screen lubricant chemistries for automotive air-conditioning compressors lubricated by R-134a (Freon substitute). Most of these findings have been reported to the DOE program office through Argonne National Laboratory who manages the overall program. A list of those reports and a copy of the report submitted to the Argonne National Laboratory is attached in Appendix A. Additional reports have also been submitted separately to DOE program managers. These are attached in Appendix B.

  10. Advances in Processing of Bulk Ferroelectric Materials

    NASA Astrophysics Data System (ADS)

    Galassi, Carmen

    The development of ferroelectric bulk materials is still under extensive investigation, as new and challenging issues are growing in relation to their widespread applications. Progress in understanding the fundamental aspects requires adequate technological tools. This would enable controlling and tuning the material properties as well as fully exploiting them into the scale production. Apart from the growing number of new compositions, interest in the first ferroelectrics like BaTiO3 or PZT materials is far from dropping. The need to find new lead-free materials, with as high performance as PZT ceramics, is pushing towards a full exploitation of bariumbased compositions. However, lead-based materials remain the best performing at reasonably low production costs. Therefore, the main trends are towards nano-size effects and miniaturisation, multifunctional materials, integration, and enhancement of the processing ability in powder synthesis. Also, in control of dispersion and packing, to let densification occur in milder conditions. In this chapter, after a general review of the composition and main properties of the principal ferroelectric materials, methods of synthesis are analysed with emphasis on recent results from chemical routes and cold consolidation methods based on the colloidal processing.

  11. Barriers to applying advanced high-temperature materials

    NASA Astrophysics Data System (ADS)

    Premkumar, M. K.

    1993-01-01

    During the past 25 years, aerospace engineers and material scientists have made significant technical progress toward developing next-generation aircraft. However, while advanced high-temperature materials continue to be developed, the outlook for their future application is uncertain and will depend on the ability of these materials to satisfy a more diverse market.

  12. Advanced materials research for long-haul aircraft turbine engines

    NASA Technical Reports Server (NTRS)

    Signorelli, R. A.; Blankenship, C. P.

    1978-01-01

    The status of research efforts to apply low to intermediate temperature composite materials and advanced high temperature materials to engine components is reviewed. Emerging materials technologies and their potential benefits to aircraft gas turbines were emphasized. The problems were identified, and the general state of the technology for near term use was assessed.

  13. Lignin-Derived Advanced Carbon Materials

    SciTech Connect

    Chatterjee, Sabornie; Saito, Tomonori

    2015-01-01

    Lignin is a highly abundant source of renewable carbon that can be considered as a valuable sustainable source of biobased materials. By application specific pretreatments and manufacturing method, lignin can be converted to a variety of value added carbon materials. However, the physical and chemical heterogenitites in lignin complicate its use as a feedstock. In this review, lignin manufacturing process, effects of pretreatments and manufacturing methods on the properties of lignin, properties and applications of various lignin derived carbon materials such as carbon fibers, carbon mats, activated carbons, carbon films; are discussed.

  14. Advances in nonlinear optical materials and devices

    NASA Technical Reports Server (NTRS)

    Byer, Robert L.

    1991-01-01

    The recent progress in the application of nonlinear techniques to extend the frequency of laser sources has come from the joint progress in laser sources and in nonlinear materials. A brief summary of the progress in diode pumped solid state lasers is followed by an overview of progress in nonlinear frequency extension by harmonic generation and parametric processes. Improved nonlinear materials including bulk crystals, quasiphasematched interactions, guided wave devices, and quantum well intersubband studies are discussed with the idea of identifying areas of future progress in nonlinear materials and devices.

  15. Lignin-Derived Advanced Carbon Materials.

    PubMed

    Chatterjee, Sabornie; Saito, Tomonori

    2015-12-01

    Lignin is a highly abundant source of renewable carbon that can be considered as a valuable sustainable source of biobased materials. By applying specific pretreatments and manufacturing methods, lignin can be converted into a variety of value-added carbon materials. However, the physical and chemical heterogeneities of lignin complicate its use as a feedstock. Herein lignin manufacturing process, the effects of pretreatments and manufacturing methods on the properties of product lignin, and structure-property relationships in various applications of lignin-derived carbon materials, such as carbon fibers, carbon mats, activated carbons, carbon films, and templated carbon, are discussed. PMID:26568373

  16. Lignin-Derived Advanced Carbon Materials

    SciTech Connect

    Chatterjee, Sabornie; Saito, Tomonori

    2015-11-16

    Lignin is a highly abundant source of renewable carbon that can be considered as a valuable sustainable source of biobased materials. By applying specific pretreatments and manufacturing methods, it has been found that lignin can be converted into a variety of value-added carbon materials. However, the physical and chemical heterogeneities of lignin complicate its use as a feedstock. Herein, we discuss the lignin manufacturing process, the effects of pretreatments and manufacturing methods on the properties of product lignin, and structure–property relationships in various applications of lignin-derived carbon materials, such as carbon fibers, carbon mats, activated carbons, carbon films, and templated carbon.

  17. Advances in design and modeling of porous materials

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

  18. Advanced diffusion studies with isotopically controlled materials

    SciTech Connect

    Bracht, Hartmut A.; Silvestri, Hughes H.; Haller, Eugene E.

    2004-11-14

    The use of enriched stable isotopes combined with modern epitaxial deposition and depth profiling techniques enables the preparation of material heterostructures, highly appropriate for self- and foreign-atom diffusion experiments. Over the past decade we have performed diffusion studies with isotopically enriched elemental and compound semiconductors. In the present paper we highlight our recent results and demonstrate that the use of isotopically enriched materials ushered in a new era in the study of diffusion in solids which yields greater insight into the properties of native defects and their roles in diffusion. Our approach of studying atomic diffusion is not limited to semiconductors and can be applied also to other material systems. Current areas of our research concern the diffusion in the silicon-germanium alloys and glassy materials such as silicon dioxide and ion conducting silicate glasses.

  19. Marine applications for advanced composite materials

    SciTech Connect

    Hihara, L.H.; Bregman, R.; Takahashi, P.K.

    1993-12-31

    Very large floating structures (VLFSs) may one day be essential to the study and utilization of the ocean. Some possible applications for VLFSs are ocean ranching homeports. observatories for ocean research, seabed mineral refineries, energy generation platforms. and waste management facilities. A VLFS that is in the conceptual phase, and may one day be based off the coast of Hawaii, has been named Blue Revolution. Candidate materials for Blue Revolution were identified based on criteria of rigidity, strength, and weight. Priority was given to materials that could be used to construct lightweight VLFSs. Major static forces were considered in this preliminary analysis. The best materials were identified as those having low values of density/modulus ({rho}/E) and density/strength ({rho}/{sigma}). Concrete, metal alloys, organic-matrix composites (OMCs), and metal-matrix composites (MMCs) were evaluated. OMCs and MMCs were generally the best materials based on their very low {rho}/E and {rho}/{sigma} values.

  20. Materials of construction for advanced coal conversion systems

    SciTech Connect

    Nangia, V.K.

    1982-01-01

    This book describes materials of construction, and materials problems for equipment used in advanced coal conversion systems. The need for cost effective industrial operation is always a prime concern, particularly in this age of energy consciousness. Industry is continually seeking improved materials for more efficient systems. The information presented here is intended to be of use in the design and planning of these systems. Coal conversion and utilization impose severe demands on construction materials because of high temperature, high pressure, corrosive/erosive, and other hostile environmental factors. Successful economic development of these processes can be achieved only to the extent that working materials can withstand increasingly more aggressive operating conditions. The book, which reviews present and past work on the behavior of materials in the environments of advanced coal conversion systems, is divided into three parts: atmospheric fluidized bed combustion, coal gasification and liquefaction, and advanced power systems.

  1. Advanced Materials and Solids Analysis Research Core (AMSARC)

    EPA Science Inventory

    The Advanced Materials and Solids Analysis Research Core (AMSARC), centered at the U.S. Environmental Protection Agency's (EPA) Andrew W. Breidenbach Environmental Research Center in Cincinnati, Ohio, is the foundation for the Agency's solids and surfaces analysis capabilities. ...

  2. Advanced organic composite materials for aircraft structures: Future program

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Revolutionary advances in structural materials have been responsible for revolutionary changes in all fields of engineering. These advances have had and are still having a significant impact on aircraft design and performance. Composites are engineered materials. Their properties are tailored through the use of a mix or blend of different constituents to maximize selected properties of strength and/or stiffness at reduced weights. More than 20 years have passed since the potentials of filamentary composite materials were identified. During the 1970s much lower cost carbon filaments became a reality and gradually designers turned from boron to carbon composites. Despite progress in this field, filamentary composites still have significant unfulfilled potential for increasing aircraft productivity; the rendering of advanced organic composite materials into production aircraft structures was disappointingly slow. Why this is and research and technology development actions that will assist in accelerating the application of advanced organic composites to production aircraft is discussed.

  3. Advanced Engineering Materials: Products from Super Stuff. Resources in Technology.

    ERIC Educational Resources Information Center

    Jacobs, James A.

    1993-01-01

    Discusses the development of "smart" or advanced materials such as ceramics, metals, composites, and polymers. Provides a design brief, a student learning activity with outcomes, quiz, and resources. (SK)

  4. Biosynthetic Polymers as Functional Materials

    PubMed Central

    2016-01-01

    The synthesis of functional polymers encoded with biomolecules has been an extensive area of research for decades. As such, a diverse toolbox of polymerization techniques and bioconjugation methods has been developed. The greatest impact of this work has been in biomedicine and biotechnology, where fully synthetic and naturally derived biomolecules are used cooperatively. Despite significant improvements in biocompatible and functionally diverse polymers, our success in the field is constrained by recognized limitations in polymer architecture control, structural dynamics, and biostabilization. This Perspective discusses the current status of functional biosynthetic polymers and highlights innovative strategies reported within the past five years that have made great strides in overcoming the aforementioned barriers. PMID:27375299

  5. Advances in thin film photonics: materials, science, and technology

    NASA Astrophysics Data System (ADS)

    Fortmann, Charles M.; Tonucci, Ronald J.; Anderson, Wayne A.; Teplin, C. W.; Mahan, A. H.

    2003-10-01

    Control of refractive index in amorphous silicon materials is investigated. Elementary waveguide structures were prepared on two micron thick amorphous silicon by photon lithographic patterning of a silver masking layer. Hydrogen was implanted at fluence of ~5×1017 cm2 for three energies, 50, 100 and 175 KeV yielding a total does of ~1.5×1018 cm2 consistent with a 10% increase in atoms due to the hydrogen addition. The optical properties of the implanted and non-implanted regions were probed as a function of low temperature annealing. The optical band gap shift to higher energy was consistent with hydrogen addition. Some darkening, absorption increase, were noted on the implanted regions. However, low temperature annealing is known to remove dangling bond damage in amorphous silicon. Prospects of utilizing these waveguides to probe light induced optical changes in amorphous silicon is described as well as the prospects of more advanced devices.

  6. Lignin-Derived Advanced Carbon Materials

    DOE PAGESBeta

    Chatterjee, Sabornie; Saito, Tomonori

    2015-11-16

    Lignin is a highly abundant source of renewable carbon that can be considered as a valuable sustainable source of biobased materials. By applying specific pretreatments and manufacturing methods, it has been found that lignin can be converted into a variety of value-added carbon materials. However, the physical and chemical heterogeneities of lignin complicate its use as a feedstock. Herein, we discuss the lignin manufacturing process, the effects of pretreatments and manufacturing methods on the properties of product lignin, and structure–property relationships in various applications of lignin-derived carbon materials, such as carbon fibers, carbon mats, activated carbons, carbon films, and templatedmore » carbon.« less

  7. Recent Advancements in Functionalized Paper-Based Electronics.

    PubMed

    Lin, Yang; Gritsenko, Dmitry; Liu, Qian; Lu, Xiaonan; Xu, Jie

    2016-08-17

    Building electronic devices on ubiquitous paper substrates has recently drawn extensive attention due to its light weight, low cost, environmental friendliness, and ease of fabrication. Recently, a myriad of advancements have been made to improve the performance of paper electronics for various applications, such as basic electronic components, energy storage devices, generators, antennas, and electronic circuits. This review aims to summarize this progress and discuss different perspectives of paper electronics as well as the remaining challenges yet to be overcome in this field. Other aspects included in this review are the fundamental characteristics of paper, modification of paper with functional materials, and various methods for device fabrication. PMID:27463253

  8. Fabrication of Advanced Thermoelectric Materials by Hierarchical Nanovoid Generation

    NASA Technical Reports Server (NTRS)

    Choi, Sang Hyouk (Inventor); Park, Yeonjoon (Inventor); Chu, Sang-Hyon (Inventor); Elliott, James R. (Inventor); King, Glen C. (Inventor); Kim, Jae-Woo (Inventor); Lillehei, Peter T. (Inventor); Stoakley, Diane M. (Inventor)

    2011-01-01

    A novel method to prepare an advanced thermoelectric material has hierarchical structures embedded with nanometer-sized voids which are key to enhancement of the thermoelectric performance. Solution-based thin film deposition technique enables preparation of stable film of thermoelectric material and void generator (voigen). A subsequent thermal process creates hierarchical nanovoid structure inside the thermoelectric material. Potential application areas of this advanced thermoelectric material with nanovoid structure are commercial applications (electronics cooling), medical and scientific applications (biological analysis device, medical imaging systems), telecommunications, and defense and military applications (night vision equipments).

  9. Evaluation of advanced materials. Final report

    SciTech Connect

    Wright, I.G.; Clauer, A.H.; Shetty, D.K.; Tucker, T.R.; Stropki, J.T.

    1982-11-18

    Cemented tungsten carbides with a binder level in the range of 5 to 6 percent exhibited the best resistance to erosion for this class of materials. Other practical cermet meterials were diamond - Si/SiC, Al/sub 2/O/sub 3/-B/sub 4/C-Cr, and B/sub 4/C-Co. SiAlON exhibited erosion resistance equivalent to the best WC-cermet. The only coating system to show promise of improved erosion resistance was CVD TiB/sub 2/ on cemented TiB/sub 2/-Ni. Cracking and/or spalling of a TiC coating and a proprietary TMT coating occurred in the standard slurry erosion test. Ranking of cemented tungsten carbide materials in the laboratory erosion test was the same as that found in service in the Wilsonville pilot plant. Specimens from the Fort Lewis pilot plant which performed well in service exhibited low erosion in the laboratory test. A substitute slurry, was found to be 2 to 4 times more erosive than the coal-derived slurry 8 wt% solids. Ranking of materials in the substitute slurry was nearly identical to that in the coal-derived slurry. Three modes of erosion were: ductile cutting; elastic-plastic indentation and fracture; and intergranular fracture. Erosion of a given material was closely related to its microstructure. In the substitute slurry, the angle-dependence of erosion of two forms of SiC, hot-pressed and sintered, were similar, but the sintered material eroded slower. Laser fusing of preplaced powder mixtures can produce cermet-like structures with potential for erosive and sliding wear resistance. TiC particles in Stellite 6 matrix proved less prone to cracking than WC particles in the same matrix. 74 figures, 14 tables.

  10. Advances in electrode materials for AMTEC

    NASA Astrophysics Data System (ADS)

    Ryan, M. A.; Williams, R. M.; Lara, L.; Fiebig, B. G.; Cortez, R. H.; Kisor, A. K.; Shields, V. B.; Homer, M. L.

    2001-02-01

    A mixed conducting electrode for the Alkali Metal Thermal to Electric Converter (AMTEC) has been made and tested. The electrode is made from a slurry of metal and TiO2 powders which is applied to the electrolyte and fired to sinter the electrode material. During the first 48-72 hours of operation in a SETC, the electrode takes up Na from low pressure sodium vapor to make a metal-Na-Ti-O compound. This compound is electronically conducting and ionically conducting to sodium; electronic conduction is also provided by the metal in the electrode. With a mixed conducting electrode made from robust, low vapor pressure materials, the promise for improved performance and lifetime is high. .

  11. PREFACE: Advanced Materials for Demanding Applications

    NASA Astrophysics Data System (ADS)

    McMillan, Alison; Schofield, Stephen; Kelly, Michael

    2015-02-01

    This was a special conference. It was small enough (60+ delegates) but covering a wide range of topics, under a broad end-use focussed heading. Most conferences today either have hundreds or thousands of delegates or are small and very focussed. The topics ranged over composite materials, the testing of durability aspects of materials, and an eclectic set of papers on radar screening using weak ionized plasmas, composites for microvascular applications, composites in space rockets, and materials for spallation neutron sources etc. There were several papers of new characterisation techniques and, very importantly, several papers that started with the end-user requirements leading back into materials selection. In my own area, there were three talks about the technology for the ultra-precise positioning of individual atoms, donors, and complete monolayers to take modern electronics and optoelectronics ideas closer to the market place. The President of the Institute opened with an experience-based talk on translating innovative technology into business. Everyone gave a generous introduction to bring all-comers up to speed with the burning contemporary issues. Indeed, I wish that a larger cohort of first-year engineering PhD students were present to see the full gamut of what takes a physics idea to a success in the market place. I would urge groups to learn from Prof Alison McMillan (a Vice President of the Institute of Physics) and Steven Schofield, to set up conferences of similar scale and breadth. I took in more than I do from mega-meetings, and in greater depth. Professor Michael Kelly Department of Engineering University of Cambridge

  12. Polymers Advance Heat Management Materials for Vehicles

    NASA Technical Reports Server (NTRS)

    2013-01-01

    For 6 years prior to the retirement of the Space Shuttle Program, the shuttles carried an onboard repair kit with a tool for emergency use: two tubes of NOAX, or "good goo," as some people called it. NOAX flew on all 22 flights following the Columbia accident, and was designed to repair damage that occurred on the exterior of the shuttle. Bill McMahon, a structural materials engineer at Marshall Space Flight Center says NASA needed a solution for the widest range of possible damage to the shuttle s exterior thermal protection system. "NASA looked at several options in early 2004 and decided on a sealant. Ultimately, NOAX performed the best and was selected," he says. To prove NOAX would work effectively required hundreds of samples manufactured at Marshall and Johnson, and a concerted effort from various NASA field centers. Johnson Space Center provided programmatic leadership, testing, tools, and crew training; Glenn Research Center provided materials analysis; Langley Research Center provided test support and led an effort to perform large patch repairs; Ames Research Center provided additional testing; and Marshall provided further testing and the site of NOAX manufacturing. Although the sealant never had to be used in an emergency situation, it was tested by astronauts on samples of reinforced carbon-carbon (RCC) during two shuttle missions. (RCC is the thermal material on areas of the shuttle that experience the most heat, such as the nose cone and wing leading edges.) The material handled well on orbit, and tests showed the NOAX patch held up well on RCC.

  13. Advanced Materials and Coatings for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    2004-01-01

    In the application area of aerospace tribology, researchers and developers must guarantee the highest degree of reliability for materials, components, and systems. Even a small tribological failure can lead to catastrophic results. The absence of the required knowledge of tribology, as Professor H.P. Jost has said, can act as a severe brake in aerospace vehicle systems-and indeed has already done so. Materials and coatings must be able to withstand the aerospace environments that they encounter, such as vacuum terrestrial, ascent, and descent environments; be resistant to the degrading effects of air, water vapor, sand, foreign substances, and radiation during a lengthy service; be able to withstand the loads, stresses, and temperatures encountered form acceleration and vibration during operation; and be able to support reliable tribological operations in harsh environments throughout the mission of the vehicle. This presentation id divided into two sections: surface properties and technology practice related to aerospace tribology. The first section is concerned with the fundamental properties of the surfaces of solid-film lubricants and related materials and coatings, including carbon nanotubes. The second is devoted to applications. Case studies are used to review some aspects of real problems related to aerospace systems to help engineers and scientists to understand the tribological issues and failures. The nature of each problem is analyzed, and the tribological properties are examined. All the fundamental studies and case studies were conducted at the NASA Glenn Research Center.

  14. Cladding and Duct Materials for Advanced Nuclear Recycle Reactors

    SciTech Connect

    Allen, Todd R.; Busby, Jeremy T; Klueh, Ronald L; Maloy, S; Toloczko, M

    2008-01-01

    The expanded use of nuclear energy without risk of nuclear weapons proliferation and with safe nuclear waste disposal is a primary goal of the Global Nuclear Energy Partnership (GNEP). To achieve that goal the GNEP is exploring advanced technologies for recycling spent nuclear fuel that do not separate pure plutonium, and advanced reactors that consume transuranic elements from recycled spent fuel. The GNEP s objectives will place high demands on reactor clad and structural materials. This article discusses the materials requirements of the GNEP s advanced nuclear recycle reactors program.

  15. Advanced STEM Characterization of Nanoscale Materials

    NASA Astrophysics Data System (ADS)

    Dey, Sanchita

    Nanoscale materials are the key structures in determining the properties of many technologically-important materials. Two such important nanoscale materials for different technological applications are investigated in this dissertation. They are: Fischer-Tropsch (FT) catalysts and irradiated metallic bi-layers. Catalytic activity depends on the structural parameters such as size, shape, and distribution on support. On the other hand, the radiation resistance of the model metallic multi-layers is influenced by the presence of interphase, phase-boundaries, and grain-boundaries. The focus of this dissertation is to use different TEM and STEM techniques to understand the structure of these materials. This dissertation begins with a review of the microscopy techniques used in the experiments. Then, in the next two chapters, literature review followed by results and discussions on the two above-mentioned nano materials are presented. Future research directions are included in the concluding chapter. To obtain three-dimensional morphological information of the FT catalysts during reduced/active state, STEM tomography is used. The oxidized state and reduced state is clarified by using STEM-EELS (in the form of spectrum imaging). We used a special vacuum transfer tomography holder and ex-situ gas assembly for reduction, and the reduction parameters are optimized for complete reduction. It was observed that the particle was reduced with 99.99% H2, and at 400°C for 15 minutes. The tomographic results in before-reduction condition depict that the Co-oxide particles are distributed randomly inside the alumina support. After reduction, the tomogram reveals that metallic Co nucleated and sintered towards the surface of the alumina support. The overall metallic Co distribution shows an outward segregation by subsurface diffusion mechanism. In the study of metallic bi-layer, He-irradiated gold twist grain boundary (AuTGB) was chosen as it is one of the least-studied systems in the

  16. Advanced proton-exchange materials for energy efficient fuel cells.

    SciTech Connect

    Fujimoto, Cy H.; Grest, Gary Stephen; Hickner, Michael A.; Cornelius, Christopher James; Staiger, Chad Lynn; Hibbs, Michael R.

    2005-12-01

    The ''Advanced Proton-Exchange Materials for Energy Efficient Fuel Cells'' Laboratory Directed Research and Development (LDRD) project began in October 2002 and ended in September 2005. This LDRD was funded by the Energy Efficiency and Renewable Energy strategic business unit. The purpose of this LDRD was to initiate the fundamental research necessary for the development of a novel proton-exchange membranes (PEM) to overcome the material and performance limitations of the ''state of the art'' Nafion that is used in both hydrogen and methanol fuel cells. An atomistic modeling effort was added to this LDRD in order to establish a frame work between predicted morphology and observed PEM morphology in order to relate it to fuel cell performance. Significant progress was made in the area of PEM material design, development, and demonstration during this LDRD. A fundamental understanding involving the role of the structure of the PEM material as a function of sulfonic acid content, polymer topology, chemical composition, molecular weight, and electrode electrolyte ink development was demonstrated during this LDRD. PEM materials based upon random and block polyimides, polybenzimidazoles, and polyphenylenes were created and evaluated for improvements in proton conductivity, reduced swelling, reduced O{sub 2} and H{sub 2} permeability, and increased thermal stability. Results from this work reveal that the family of polyphenylenes potentially solves several technical challenges associated with obtaining a high temperature PEM membrane. Fuel cell relevant properties such as high proton conductivity (>120 mS/cm), good thermal stability, and mechanical robustness were demonstrated during this LDRD. This report summarizes the technical accomplishments and results of this LDRD.

  17. Advances and new functions of VCSEL photonics

    NASA Astrophysics Data System (ADS)

    Koyama, Fumio

    2014-11-01

    A vertical cavity surface emitting laser (VCSEL) was born in Japan. The 37 years' research and developments opened up various applications including datacom, sensors, optical interconnects, spectroscopy, optical storages, printers, laser displays, laser radar, atomic clock and high power sources. A lot of unique features have been already proven, such as low power consumption, a wafer level testing and so on. The market of VCSELs has been growing up rapidly and they are now key devices in local area networks based on multi-mode optical fibers. Optical interconnections in data centers and supercomputers are attracting much interest. In this paper, the advances on VCSEL photonics will be reviewed. We present the high-speed modulation of VCSELs based on a coupled cavity structure. For further increase in transmission capacity per fiber, the wavelength engineering of VCSEL arrays is discussed, which includes the wavelength stabilization and wavelength tuning based on a micro-machined cantilever structure. We also address a lateral integration platform and new functions, including high-resolution beam scanner, vortex beam creation and large-port free space wavelength selective switch with a Bragg reflector waveguide.

  18. An advanced material science payload for GAS

    NASA Technical Reports Server (NTRS)

    Joensson, R.; Wallin, S.; Loeth, K.

    1986-01-01

    The aim of the experiment is to study solidification of different compositions of lead-tin. The weight of the material is quite high: 8 kilograms. Nearly 10% of the payload is sample weight. The dendritic growth and the effect of the absence of natural convection are of particular interest. The results from the flight processed samples will be compared with results from Earth processed samples in order to investigate the influence of the natural convection on the solidification process. The power systems, heat storage and rejection, and mechanical support are discussed in relationship to the scientific requirements.

  19. Advances in high-tech materials: Datafile III

    SciTech Connect

    Not Available

    1987-01-01

    The important technical developments in materials engineering of 1986 are reported in this survey, which provides details of the inventions and advances achieved in laboratories and universities around the world. The report also forecasts future developments in materials engineering. A list of promising licensing opportunities is included.

  20. Synthesis and characterization of advanced materials for Navy applications

    NASA Technical Reports Server (NTRS)

    Covino, J.; Lee, I.

    1994-01-01

    The synthesis of ceramics and ceramic coatings through the sol-gel process has extensive application with the United States Navy and a broad range of potential commercial applications as well. This paper surveys seven specific applications for which the Navy is investigating these advanced materials. For each area, the synthetic process is described and the characteristics of the materials are discussed.

  1. Advanced computational research in materials processing for design and manufacturing

    SciTech Connect

    Zacharia, T.

    1995-04-01

    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.

  2. Characterization of advanced preprocessed materials (Hydrothermal)

    SciTech Connect

    Rachel Emerson; Garold Gresham

    2012-09-01

    The initial hydrothermal treatment parameters did not achieve the proposed objective of this effort; the reduction of intrinsic ash in the corn stover. However, liquid fractions from the 170°C treatments was indicative that some of the elements routinely found in the ash that negatively impact the biochemical conversion processes had been removed. After reviewing other options for facilitating ash removal, sodium-citrate (chelating agent) was included in the hydrothermal treatment process, resulting in a 69% reduction in the physiological ash. These results indicated that chelation –hydrothermal treatment is one possible approach that can be utilized to reduce the overall ash content of feedstock materials and having a positive impact on conversion performance.

  3. Experiments investigating advanced materials under thermomechanical loading

    NASA Technical Reports Server (NTRS)

    Bartolotta, Paul A.

    1988-01-01

    Many high temperature aircraft and rocket engine components experience large mechanical loads as well as severe thermal gradients and transients. These nonisothermal conditions are often large enough to cause inelastic deformations, which are the ultimate cause for failure in those parts. A way to alleviate this problem is through improved engine designs based on better predictions of thermomechanical material behavior. To address this concern, an experimental effort was recently initiated within the Hot Section Technology (HOST) program at Lewis. As part of this effort, two new test systems were added to the Fatigue and Structures Lab., which allowed thermomechanical tests to be conducted under closely controlled conditions. These systems are now being used for thermomechanical testing for the Space Station Receiver program, and will be used to support development of metal matrix composites.

  4. Combustion synthesis of advanced composite materials

    NASA Technical Reports Server (NTRS)

    Moore, John J.

    1993-01-01

    Self-propagating high temperature (combustion) synthesis (SHS), has been investigated as a means of producing both dense and expanded (foamed) ceramic and ceramic-metal composites, ceramic powders and whiskers. Several model exothermic combustion synthesis reactions were used to establish the importance of certain reaction parameters, e.g., stoichiometry, green density, combustion mode, particle size, etc. on the control of the synthesis reaction, product morphology and properties. The use of an in situ liquid infiltration technique and the effect of varying the reactants and their stoichiometry to provide a range of reactant and product species i.e., solids, liquids and gases, with varying physical properties e.g., volatility and thermal conductivity, on the microstructure and morphology of synthesized composite materials is discussed. Conducting the combustion synthesis reaction in a reactive gas environment to take advantage of the synergistic effects of combustion synthesis and vapor phase transport is also examined.

  5. Advances in amorphous and nanocrystalline materials

    NASA Astrophysics Data System (ADS)

    Hasegawa, Ryusuke

    2012-10-01

    A new amorphous alloy has been recently introduced which shows a saturation magnetic induction Bs of 1.64 T which is compared with Bs=1.57 T for a currently available Fe-based amorphous alloy and decreased magnetic losses. Such a combination is rare but can be explained in terms of induced magnetic anisotropy being reduced by the alloy's chemistry and its heat treatment. It has been found that the region of magnetization rotation in the new alloy is considerably narrowed, resulting in reduced exciting power in the magnetic devices utilizing the material. Efforts to increase Bs also have been made for nanocrystalline alloys. For example, a nanocrystalline alloy having a composition of Fe80.5Cu1.5Si4B14 shows Bs exceeding 1.8 T. The iron loss at 50 Hz and at 1.6 T induction in a toroidal core of this material is 0.46 W/kg which is 2/3 that of a grain-oriented silicon steel. At 20 kHz/0.2 T excitation, the iron loss is about 60% of that in an Fe-based amorphous alloy which is widely used in power electronics. Another example is a Fe85Si2B8P4Cu1 nanocrystalline alloy with a Bs of 1.8 T, which is reported to exhibit a magnetic core loss of about 0.2 W/kg at 50 Hz and at 1.5 T induction. This article is a review of these new developments and their impacts on energy efficient magnetic devices.

  6. Surface chemical deposition of advanced electronic materials

    NASA Astrophysics Data System (ADS)

    Bjelkevig, Cameron

    The focus of this work was to examine the direct plating of Cu on Ru diffusion barriers for use in interconnect technology and the substrate mediated growth of graphene on boron nitride for use in advanced electronic applications. The electrodeposition of Cu on Ru(0001) and polycrystalline substrates (with and without pretreatment in an iodine containing solution) has been studied by cyclic voltammetry (CV), current--time transient measurements (CTT), in situ electrochemical atomic force microscopy (EC-AFM), and X-ray photoelectron spectroscopy (XPS). The EC-AFM data show that at potentials near the OPD/UPD threshold, Cu crystallites exhibit pronounced growth anisotropy, with lateral dimensions greatly exceeding vertical dimensions. XPS measurements confirmed the presence and stability of adsorbed I on the Ru surface following pre-treatment in a KI/H2SO4 solution and following polarization to at least -200 mV vs. Ag/AgCl. CV data of samples pre-reduced in I-containing electrolyte exhibited a narrow Cu deposition peak in the overpotential region and a UPD peak. The kinetics of the electrodeposited Cu films was investigated by CTT measurements and applied to theoretical models of nucleation. The data indicated that a protective I adlayer may be deposited on an airexposed Ru electrode as the oxide surface is electrochemically reduced, and that this layer will inhibit reformation of an oxide during the Cu electroplating process. A novel method for epitaxial graphene growth directly on a dielectric substrate of systematically variable thickness was studied. Mono/multilayers of BN(111) were grown on Ru(0001) by atomic layer deposition (ALD), exhibiting a flat (non-nanomesh) R30(✓3x✓3) structure. BN(111) was used as a template for growth of graphene by chemical vapor deposition (CVD) of C2H4 at 1000 K. Characterization by LEED, Auger, STM/STS and Raman indicate the graphene is in registry with the BN substrate, and exhibits a HOPG-like 0 eV bandgap density

  7. Materials for advanced rocket engine turbopump turbine blades

    NASA Technical Reports Server (NTRS)

    Chandler, W. T.

    1985-01-01

    A study program was conducted to identify those materials that will provide the greatest benefits as turbine blades for advanced liquid propellant rocket engine turbines and to prepare technology plans for the development of those materials for use in the 1990 through 1995 period. The candidate materials were selected from six classes of materials: single-crystal (SC) superalloys, oxide dispersion-strengthened (ODS) superalloys, rapid solidification processed (RSP) superalloys, directionally solidified eutectic (DSE) superalloys, fiber-reinforced superalloy (FRS) composites, and ceramics. Properties of materials from the six classes were compiled and evaluated and property improvements were projected approximately 5 years into the future for advanced versions of materials in each of the six classes.

  8. SYNTHESIS AND CHARACTERIZATION OF ADVANCED MAGNETIC MATERIALS

    SciTech Connect

    Monica Sorescu

    2004-09-22

    The work described in this grant report was focused mainly on the properties of novel magnetic intermetallics. In the first project, we synthesized several 2:17 intermetallic compounds, namely Nd{sub 2}Fe{sub 15}Si{sub 2}, Nd{sub 2}Fe{sub 15}Al{sub 2}, Nd{sub 2}Fe{sub 15}SiAl and Nd{sub 2}Fe{sub 15}SiMn, as well as several 1:12 intermetallic compounds, such as NdFe{sub 10}Si{sub 2}, NdFe{sub 10}Al{sub 2}, NdFe{sub 10}SiAl and NdFe{sub 10}MnAl. In the second project, seven compositions of Nd{sub x}Fe{sub 100-x-y}B{sub y} ribbons were prepared by a melt spinning method with Nd and B content increasing from 7.3 and 3.6 to 11 and 6, respectively. The alloys were annealed under optimized conditions to obtain a composite material consisting of the hard magnetic Nd{sub 2}Fe{sub 14}B and soft magnetic {alpha}-Fe phases, typical of a spring magnet structure. In the third project, intermetallic compounds of the type Zr{sub 1}Cr{sub 1}Fe{sub 1}T{sub 0.8} with T = Al, Co and Fe were subjected to hydrogenation. In the fourth project, we performed three crucial experiments. In the first experiment, we subjected a mixture of Fe{sub 3}O{sub 4} and Fe (80-20 wt %) to mechanochemical activation by high-energy ball milling, for time periods ranging from 0.5 to 14 hours. In the second experiment, we ball-milled Fe{sub 3}O{sub 4}:Co{sup 2+} (x = 0.1) for time intervals between 2.5 and 17.5 hours. Finally, we exposed a mixture of Fe{sub 3}O{sub 4} and Co (80-20 wt %) to mechanochemical activation for time periods ranging from 0.5 to 10 hours. In all cases, the structural and magnetic properties of the systems involved were elucidated by X-ray diffraction (XRD), Moessbauer spectroscopy and hysteresis loop measurements. The four projects resulted in four papers, which were published in Intermetallics, IEEE Transactions on Magnetics, Journal of Materials Science Letters and Materials Chemistry and Physics. The contributions reveal for the first time in literature the effect of

  9. MATERIALS AND COMPONENT DEVELOPMENT FOR ADVANCED TURBINE SYSTEMS PROJECT SUMMARY

    SciTech Connect

    Alvin, M A

    2010-06-18

    Future hydrogen-fired or oxy-fuel turbines will likely experience an enormous level of thermal and mechanical loading, as turbine inlet temperatures (TIT) approach 1425-1760C (2600-3200F) with pressures of 300-625 psig, respectively. Maintaining the structural integrity of future turbine components under these extreme conditions will require (1) durable thermal barrier coatings (TBCs), (2) high temperature creep resistant metal substrates, and (3) effective cooling techniques. While advances in substrate materials have been limited for the past decades, thermal protection of turbine airfoils in future hydrogen-fired and oxy-fuel turbines will rely primarily on collective advances in the TBCs and aerothermal cooling. To support the advanced turbine technology development, the Office of Research and Development (ORD) at National Energy Technology Laboratory (NETL) has continued its collaborative research efforts with the University of Pittsburgh and West Virginia University, while working in conjunction with commercial material and coating suppliers. This paper presents the technical accomplishments that were made during FY09 in the initial areas of advanced materials, aerothermal heat transfer and non-destructive evaluation techniques for use in advanced land-based turbine applications in the Materials and Component Development for Advanced Turbine Systems project, and introduces three new technology areas high temperature overlayer coating development, diffusion barrier coating development, and oxide dispersion strengthened (ODS) alloy development that are being conducted in this effort.

  10. Integration of advanced nuclear materials separation processes

    SciTech Connect

    Jarvinen, G.D.; Worl, L.A.; Padilla, D.D.; Berg, J.M.; Neu, M.P.; Reilly, S.D.; Buelow, S.

    1998-12-31

    This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project has examined the fundamental chemistry of plutonium that affects the integration of hydrothermal technology into nuclear materials processing operations. Chemical reactions in high temperature water allow new avenues for waste treatment and radionuclide separation.Successful implementation of hydrothermal technology offers the potential to effective treat many types of radioactive waste, reduce the storage hazards and disposal costs, and minimize the generation of secondary waste streams. The focus has been on the chemistry of plutonium(VI) in solution with carbonate since these are expected to be important species in the effluent from hydrothermal oxidation of Pu-containing organic wastes. The authors investigated the structure, solubility, and stability of the key plutonium complexes. Installation and testing of flow and batch hydrothermal reactors in the Plutonium Facility was accomplished. Preliminary testing with Pu-contaminated organic solutions gave effluent solutions that readily met discard requirements. A new effort in FY 1998 will build on these promising initial results.

  11. Simulation Toolkit for Renewable Energy Advanced Materials Modeling

    2013-11-13

    STREAMM is a collection of python classes and scripts that enables and eases the setup of input files and configuration files for simulations of advanced energy materials. The core STREAMM python classes provide a general framework for storing, manipulating and analyzing atomic/molecular coordinates to be used in quantum chemistry and classical molecular dynamics simulations of soft materials systems. The design focuses on enabling the interoperability of materials simulation codes such as GROMACS, LAMMPS and Gaussian.

  12. Numerical Simulations and Optimisation in Forming of Advanced Materials

    NASA Astrophysics Data System (ADS)

    Huétink, J.

    2007-04-01

    With the introduction of new materials as high strength steels, metastable steels and fiber reinforce composites, the need for advanced physically valid constitutive models arises. A biaxial test equipment is developed and applied for the determination of material data as well as for validation of material models. An adaptive through- thickness integration scheme for plate elements is developed, which improves the accuracy of spring back prediction at minimal costs. An optimization strategy is proposed that assists an engineer to model an optimization problem.

  13. Fossil Energy Advanced Research and Technology Development Materials Program

    SciTech Connect

    Cole, N.C.; Judkins, R.R.

    1992-12-01

    Objective of this materials program is to conduct R and D on materials for fossil energy applications with focus on longer-term and generic needs of the various fossil fuel technologies. The projects are organized according to materials research areas: (1) ceramics, (2) new alloys: iron aluminides, advanced austenitics and chromium niobium alloys, and (3) technology development and transfer. Separate abstracts have been prepared.

  14. MATERIALS AEROMETRIC DATABASE FOR USE IN DEVELOPING MATERIALS DAMAGE FUNCTION

    EPA Science Inventory

    Meteorological and air quality data acquired at field exposure sites have been accumulated into the Materials Aerometric Database (MAD). Task Group VII of the National Acid Precipitation Assessment Program (NAPAP) will use the MAD to develop damage functions for materials exposed...

  15. Advanced Industrial Materials (AIM) Program: Annual progress report FY 1995

    SciTech Connect

    1996-04-01

    In many ways, the Advanced Industrial Materials (AIM) Program underwent a major transformation in Fiscal Year 1995 and these changes have continued to the present. When the Program was established in 1990 as the Advanced Industrial Concepts (AIC) Materials Program, the mission was to conduct applied research and development to bring materials and processing technologies from the knowledge derived from basic research to the maturity required for the end use sectors for commercialization. In 1995, the Office of Industrial Technologies (OIT) made radical changes in structure and procedures. All technology development was directed toward the seven ``Vision Industries`` that use about 80% of industrial energy and generated about 90% of industrial wastes. The mission of AIM has, therefore, changed to ``Support development and commercialization of new or improved materials to improve productivity, product quality, and energy efficiency in the major process industries.`` Though AIM remains essentially a National Laboratory Program, it is essential that each project have industrial partners, including suppliers to, and customers of, the seven industries. Now, well into FY 1996, the transition is nearly complete and the AIM Program remains reasonably healthy and productive, thanks to the superb investigators and Laboratory Program Managers. This Annual Report for FY 1995 contains the technical details of some very remarkable work by the best materials scientists and engineers in the world. Areas covered here are: advanced metals and composites; advanced ceramics and composites; polymers and biobased materials; and new materials and processes.

  16. Code qualification of structural materials for AFCI advanced recycling reactors.

    SciTech Connect

    Natesan, K.; Li, M.; Majumdar, S.; Nanstad, R.K.; Sham, T.-L.

    2012-05-31

    This report summarizes the further findings from the assessments of current status and future needs in code qualification and licensing of reference structural materials and new advanced alloys for advanced recycling reactors (ARRs) in support of Advanced Fuel Cycle Initiative (AFCI). The work is a combined effort between Argonne National Laboratory (ANL) and Oak Ridge National Laboratory (ORNL) with ANL as the technical lead, as part of Advanced Structural Materials Program for AFCI Reactor Campaign. The report is the second deliverable in FY08 (M505011401) under the work package 'Advanced Materials Code Qualification'. The overall objective of the Advanced Materials Code Qualification project is to evaluate key requirements for the ASME Code qualification and the Nuclear Regulatory Commission (NRC) approval of structural materials in support of the design and licensing of the ARR. Advanced materials are a critical element in the development of sodium reactor technologies. Enhanced materials performance not only improves safety margins and provides design flexibility, but also is essential for the economics of future advanced sodium reactors. Code qualification and licensing of advanced materials are prominent needs for developing and implementing advanced sodium reactor technologies. Nuclear structural component design in the U.S. must comply with the ASME Boiler and Pressure Vessel Code Section III (Rules for Construction of Nuclear Facility Components) and the NRC grants the operational license. As the ARR will operate at higher temperatures than the current light water reactors (LWRs), the design of elevated-temperature components must comply with ASME Subsection NH (Class 1 Components in Elevated Temperature Service). However, the NRC has not approved the use of Subsection NH for reactor components, and this puts additional burdens on materials qualification of the ARR. In the past licensing review for the Clinch River Breeder Reactor Project (CRBRP) and the

  17. Advances in photonics thermal management and packaging materials

    NASA Astrophysics Data System (ADS)

    Zweben, Carl

    2008-02-01

    Heat dissipation, thermal stresses, and cost are key packaging design issues for virtually all semiconductors, including photonic applications such as diode lasers, light-emitting diodes (LEDs), solid state lighting, photovoltaics, displays, projectors, detectors, sensors and laser weapons. Heat dissipation and thermal stresses affect performance and reliability. Copper, aluminum and conventional polymeric printed circuit boards (PCBs) have high coefficients of thermal expansion, which can cause high thermal stresses. Most traditional low-coefficient-of-thermal-expansion (CTE) materials like tungsten/copper, which date from the mid 20 th century, have thermal conductivities that are no better than those of aluminum alloys, about 200 W/m-K. There are an increasing number of low-CTE materials with thermal conductivities ranging between that of copper (400 W/m-K) and 1700 W/m-K, and many other new low-CTE materials with lower thermal conductivities. An important benefit of low-CTE materials is that they allow use of hard solders. Some advanced materials are low cost. Others have the potential to be low cost in high-volume production. High-thermal-conductivity materials enable higher power levels, potentially reducing the number of required devices. Advanced thermal materials can constrain PCB CTE and greatly increase thermal conductivity. This paper reviews traditional packaging materials and advanced thermal management materials. The latter provide the packaging engineer with a greater range of options than in the past. Topics include properties, status, applications, cost, using advanced materials to fix manufacturing problems, and future directions, including composites reinforced with carbon nanotubes and other thermally conductive materials.

  18. Advances in Structural Studies of Materials using Scattering Probes

    SciTech Connect

    Huq, Ashfia; Bozin, Emil; Welberry, Dr. Richard

    2010-01-01

    Study of contemporary materials and their remarkable properties is a challenging problem. To understand these complex properties and develop better materials it is essential to understand their structures, as the two are intimately linked. Great advances in materials scattering have been achieved due to the advent of synchrotron and neutron sources along with the availability of high-speed computational algorithms. Materials scientists can now collect data with high resolution, high throughput from very small amount of sample (both single crystal and powder), and analyze vast amount of data to unravel detailed structural description that was not possible before. This article presents some of these great advances in using scattering probes for materials characterization.

  19. Deformation and Damage Studies for Advanced Structural Materials

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Advancements made in understanding deformation and damage of advanced structural materials have enabled the development of new technologies including the attainment of a nationally significant NASA Level 1 Milestone and the provision of expertise to the Shuttle Return to Flight effort. During this collaborative agreement multiple theoretical and experimental research programs, facilitating safe durable high temperature structures using advanced materials, have been conceived, planned, executed. Over 26 publications, independent assessments of structures and materials in hostile environments, were published within this agreement. This attainment has been recognized by 2002 Space Flight Awareness Team Award, 2004 NASA Group Achievement Award and 2003 and 2004 OAI Service Awards. Accomplishments in the individual research efforts are described as follows.

  20. Advanced Materials and Processing for Drug Delivery: The Past and the Future

    PubMed Central

    Zhang, Ying; Chan, Hon Fai; Leong, Kam W.

    2012-01-01

    Design and synthesis of efficient drug delivery systems are of vital importance for medicine and healthcare. Materials innovation and nanotechnology have synergistically fueled the advancement of drug delivery. Innovation in material chemistry allows the generation of biodegradable, biocompatible, environment-responsive, and targeted delivery systems. Nanotechnology enables control over size, shape and multi-functionality of particulate drug delivery systems. In this review, we focus on the materials innovation and processing of drug delivery systems and how these advances have shaped the past and may influence the future of drug delivery. PMID:23088863

  1. Crystallization and functionality of inorganic materials

    SciTech Connect

    Xue, Dongfeng; Li, Keyan; Liu, Jun; Sun, Congting; Chen, Kunfeng

    2012-10-15

    In this article, we briefly summarized our recent work on the studies of crystallization and functionality of inorganic materials. On the basis of the chemical bonding theory of single crystal growth, we can quantitatively simulate Cu{sub 2}O crystallization processes in solution system. We also kinetically controlled Cu{sub 2}O crystallization process in the reduction solution route. Lithium ion battery and supercapacitor performances of some oxides such as Co{sub 3}O{sub 4} and MnO{sub 2} were shown to elucidate the important effect of crystallization on functionality of inorganic materials. This work encourages us to create novel functionalities through the study of crystallization of inorganic materials, which warrants more chances in the field of functional materials.

  2. Advanced materials and methods for next generation spintronics

    NASA Astrophysics Data System (ADS)

    Siegel, Gene Phillip

    The modern age is filled with ever-advancing electronic devices. The contents of this dissertation continue the desire for faster, smaller, better electronics. Specifically, this dissertation addresses a field known as "spintronics", electronic devices based on an electron's spin, not just its charge. The field of spintronics originated in 1990 when Datta and Das first proposed a "spin transistor" that would function by passing a spin polarized current from a magnetic electrode into a semiconductor channel. The spins in the channel could then be manipulated by applying an electrical voltage across the gate of the device. However, it has since been found that a great amount of scattering occurs at the ferromagnet/semiconductor interface due to the large impedance mismatch that exists between the two materials. Because of this, there were three updated versions of the spintronic transistor that were proposed to improve spin injection: one that used a ferromagnetic semiconductor electrode, one that added a tunnel barrier between the ferromagnet and semiconductor, and one that utilized a ferromagnetic tunnel barrier which would act like a spin filter. It was next proposed that it may be possible to achieve a "pure spin current", or a spin current with no concurrent electric current (i.e., no net flow of electrons). One such method that was discovered is the spin Seebeck effect, which was discovered in 2008 by Uchida et al., in which a thermal gradient in a magnetic material generates a spin current which can be injected into adjacent material as a pure spin current. The first section of this dissertation addresses this spin Seebeck effect (SSE). The goal was to create such a device that both performs better than previously reported devices and is capable of operating without the aid of an external magnetic field. We were successful in this endeavor. The trick to achieving both of these goals was found to be in the roughness of the magnetic layer. A rougher magnetic

  3. Soft computing in design and manufacturing of advanced materials

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  4. Progress in advanced high temperature turbine materials, coatings, and technology

    NASA Technical Reports Server (NTRS)

    Freche, J. C.; Ault, G. M.

    1978-01-01

    Advanced materials, coatings, and cooling technology is assessed in terms of improved aircraft turbine engine performance. High cycle operating temperatures, lighter structural components, and adequate resistance to the various environmental factors associated with aircraft gas turbine engines are among the factors considered. Emphasis is placed on progress in development of high temperature materials for coating protection against oxidation, hot corrosion and erosion, and in turbine cooling technology. Specific topics discussed include metal matrix composites, superalloys, directionally solidified eutectics, and ceramics.

  5. MATERIALS AND COMPONENT DEVELOPMENT FOR ADVANCED TURBINE SYSTEMS

    SciTech Connect

    M. A. Alvin

    2009-06-12

    Future hydrogen-fired or oxy-fuel turbines will likely experience an enormous level of thermal and mechanical loading, as turbine inlet temperatures (TIT) approach 1425-1760ºC with pressures of 300-625 psig, respectively. Maintaining the structural integrity of future turbine components under these extreme conditions will require durable thermal barrier coatings (TBCs), high temperature creep resistant metal substrates, and effective cooling techniques. While advances in substrate materials have been limited for the past decades, thermal protection of turbine airfoils in future hydrogen-fired and oxy-fuel turbines will rely primarily on collective advances in TBCs and aerothermal cooling. To support the advanced turbine technology development, the National Energy Technology Laboratory (NETL) at the Office of Research and Development (ORD) has initiated a research project effort in collaboration with the University of Pittsburgh (UPitt), and West Virginia University (WVU), working in conjunction with commercial material and coating suppliers, to develop advanced materials, aerothermal configurations, as well as non-destructive evaluation techniques for use in advanced land-based gas turbine applications. This paper reviews technical accomplishments recently achieved in each of these areas.

  6. Rotorcraft digital advanced avionics system (RODAAS) functional description

    NASA Technical Reports Server (NTRS)

    Peterson, E. M.; Bailey, J.; Mcmanus, T. J.

    1985-01-01

    A functional design of a rotorcraft digital advanced avionics system (RODAAS) to transfer the technology developed for general aviation in the Demonstration Advanced Avionics System (DAAS) program to rotorcraft operation was undertaken. The objective was to develop an integrated avionics system design that enhances rotorcraft single pilot IFR operations without increasing the required pilot training/experience by exploiting advanced technology in computers, busing, displays and integrated systems design. A key element of the avionics system is the functionally distributed architecture that has the potential for high reliability with low weight, power and cost. A functional description of the RODAAS hardware and software functions is presented.

  7. The demand for advanced materials in the automotive industry: Projections for the next decade

    NASA Astrophysics Data System (ADS)

    Dupnick, Edwin; Graham, Jon

    1996-03-01

    We provide early results of an ongoing study to forecast the market for advanced high strength-to-weight materials in the U.S. automotive industry based on three supporting tasks. The first is a systematic case study of material substitution which emphasizes the application of advanced composite materials and aluminum alloys. This is accomplished by using a minimization model that considers the economic and engineering factors involved in materials substitution for one specific automobile model and is the focus of this paper. The second task will be to predict the weight reduction that would be required for each car type in the domestic fleet to meet post 2000 fuel efficiency requirements. This task will be accomplished using an analytical model of the domestic automobile fleet. The third task involves projections on the size and composition of the eventual market for advanced composite materials and aluminum alloys. This task will be performed using the results of the analytical model and the case study to project graphite fiber, fiberglass, and aluminum alloy use. The result will provide an estimate of the quantity of advanced materials that would be used by the U.S. automobile industry in the time period after 2000 as a function of technology, automobile performance standards and the costs of advanced composites, aluminum alloys, and other materials used in automobile manufacturing. As a follow-on to the subject study, ECON is examining specific market opportunities in this area for private industry clients.

  8. ADVANCED HOT SECTION MATERIALS AND COATINGS TEST RIG

    SciTech Connect

    Scott Reome; Dan Davies

    2004-04-30

    The Hyperbaric Advanced Hot Section Materials & Coating Test Rig program provides design and implementation of a laboratory rig capable of simulating the hot gas path conditions of coal-gas fired industrial gas turbine engines. The principal activity during this reporting period were the evaluation of syngas combustor concepts, the evaluation of test section concepts and the selection of the preferred rig configuration.

  9. Advanced Hot Section Materials and Coatings Test Rig

    SciTech Connect

    Dan Davies

    2004-10-30

    The Hyperbaric Advanced Hot Section Materials & Coating Test Rig program provides design and implementation of a laboratory rig capable of simulating the hot gas path conditions of coal-gas fired industrial gas turbine engines. The principal activities during this reporting period were the continuation of test section detail design and developing specifications for auxiliary systems and facilities.

  10. Advanced Packaging Materials and Techniques for High Power TR Module: Standard Flight vs. Advanced Packaging

    NASA Technical Reports Server (NTRS)

    Hoffman, James Patrick; Del Castillo, Linda; Miller, Jennifer; Jenabi, Masud; Hunter, Donald; Birur, Gajanana

    2011-01-01

    The higher output power densities required of modern radar architectures, such as the proposed DESDynI [Deformation, Ecosystem Structure, and Dynamics of Ice] SAR [Synthetic Aperture Radar] Instrument (or DSI) require increasingly dense high power electronics. To enable these higher power densities, while maintaining or even improving hardware reliability, requires advances in integrating advanced thermal packaging technologies into radar transmit/receive (TR) modules. New materials and techniques have been studied and compared to standard technologies.

  11. Higher-Order Theory for Functionally Graded Materials

    NASA Technical Reports Server (NTRS)

    Aboudi, J.; Pindera, M. J.; Arnold, Steven M.

    2001-01-01

    Functionally graded materials (FGM's) are a new generation of engineered materials wherein the microstructural details are spatially varied through nonuniform distribution of the reinforcement phase(s). Engineers accomplish this by using reinforcements with different properties, sizes, and shapes, as well as by interchanging the roles of the reinforcement and matrix phases in a continuous manner (ref. 1). The result is a microstructure that produces continuously or discretely changing thermal and mechanical properties at the macroscopic or continuum scale. This new concept of engineering the material's microstructure marks the beginning of a revolution both in the materials science and mechanics of materials areas since it allows one, for the first time, to fully integrate the material and structural considerations into the final design of structural components. Functionally graded materials are ideal candidates for applications involving severe thermal gradients, ranging from thermal structures in advanced aircraft and aerospace engines to computer circuit boards. Owing to the many variables that control the design of functionally graded microstructures, full exploitation of the FGM's potential requires the development of appropriate modeling strategies for their response to combined thermomechanical loads. Previously, most computational strategies for the response of FGM's did not explicitly couple the material's heterogeneous microstructure with the structural global analysis. Rather, local effective or macroscopic properties at a given point within the FGM were first obtained through homogenization based on a chosen micromechanics scheme and then subsequently used in a global thermomechanical analysis.

  12. Materials/manufacturing element of the Advanced Turbine Systems Program

    SciTech Connect

    Karnitz, M.A.; Holcomb, R.S.; Wright, I.G.

    1995-10-01

    The technology based portion of the Advanced Turbine Systems Program (ATS) contains several subelements which address generic technology issues for land-based gas-turbine systems. One subelement is the Materials/Manufacturing Technology Program which is coordinated by DOE-Oak Ridge Operations and Oak Ridge National Laboratory (ORNL). The work in this subelement is being performed predominantly by industry with assistance from universities and the national laboratories. Projects in this subelement are aimed toward hastening the incorporation of new materials and components in gas turbines. A materials/manufacturing plan was developed in FY 1994 with input from gas turbine manufacturers, materials suppliers, universities, and government laboratories. The plan outlines seven major subelements which focus on materials issues and manufacturing processes. Work is currently under way in four of the seven major subelements. There are now major projects on coatings and process development, scale-up of single crystal airfoil manufacturing technology, materials characterization, and technology information exchange.

  13. Corrosion performance of advanced structural materials in sodium.

    SciTech Connect

    Natesan, K.; Momozaki, Y.; Li, M.; Rink, D.L.

    2012-05-16

    This report gives a description of the activities in design, fabrication, construction, and assembling of a pumped sodium loop for the sodium compatibility studies on advanced structural materials. The work is the Argonne National Laboratory (ANL) portion of the effort on the work project entitled, 'Sodium Compatibility of Advanced Fast Reactor Materials,' and is a part of Advanced Materials Development within the Reactor Campaign. The objective of this project is to develop information on sodium corrosion compatibility of advanced materials being considered for sodium reactor applications. This report gives the status of the sodium pumped loop at Argonne National Laboratory, the specimen details, and the technical approach to evaluate the sodium compatibility of advanced structural alloys. This report is a deliverable from ANL in FY2010 (M2GAN10SF050302) under the work package G-AN10SF0503 'Sodium Compatibility of Advanced Fast Reactor Materials.' Two reports were issued in 2009 (Natesan and Meimei Li 2009, Natesan et al. 2009) which examined the thermodynamic and kinetic factors involved in the purity of liquid sodium coolant for sodium reactor applications as well as the design specifications for the ANL pumped loop for testing advanced structural materials. Available information was presented on solubility of several metallic and nonmetallic elements along with a discussion of the possible mechanisms for the accumulation of impurities in sodium. That report concluded that the solubility of many metals in sodium is low (<1 part per million) in the temperature range of interest in sodium reactors and such trace amounts would not impact the mechanical integrity of structural materials and components. The earlier report also analyzed the solubility and transport mechanisms of nonmetallic elements such as oxygen, nitrogen, carbon, and hydrogen in laboratory sodium loops and in reactor systems such as Experimental Breeder Reactor-II, Fast Flux Test Facility, and

  14. Advanced Propulsion Research Interest in Materials for Propulsion

    NASA Technical Reports Server (NTRS)

    Cole, John

    2003-01-01

    This viewgraph presentation provides an overview of material science and technology in the area of propulsion energetics. The authors note that conventional propulsion systems are near peak performance and further refinements in manufacturing, engineering design and materials will only provide incremental increases in performance. Energetic propulsion technologies could potential solve the problems of energy storage density and energy-to-thrust conversion efficiency. Topics considered include: the limits of thermal propulsion systems, the need for energetic propulsion research, emerging energetic propulsion technologies, materials research needed for advanced propulsion, and potential research opportunities.

  15. Materials/manufacturing element of the Advanced Turbine System Program

    SciTech Connect

    Karnitz, M.A.; Devan, J.H.; Holcomb, R.S.; Ferber, M.K.; Harrison, R.W.

    1994-08-01

    One of the supporting elements of the Advanced Turbine Systems (ATS) Program is the materials/manufacturing technologies task. The objective of this element is to address critical materials issues for both industrial and utility gas turbines. DOE Oak Ridge Operations Office (ORO) will manage this element of the program, and a team from DOE-ORO and Oak Ridge National Laboratory is coordinating the planning for the materials/manufacturing effort. This paper describes that planning activity which is in the early stages.

  16. Ceramic matrix composites -- Advanced high-temperature structural materials

    SciTech Connect

    Lowden, R.A.; Ferber, M.K.; Hellmann, J.R.; Chawla, K.K.; DiPietro, S.G.

    1995-10-01

    This symposium on Ceramic Matrix Composites: Advanced High-Temperature Structural Materials was held at the 1994 MRS Fall Meeting in Boston, Massachusetts on November 28--December 2. The symposium was sponsored by the Department of Energy`s Office of Industrial Technology`s Continuous Fiber Ceramic Composites Program, the Air Force Office of Scientific Research, and NASA Lewis Research Center. Among the competing materials for advanced, high-temperature applications, ceramic matrix composites are leading candidates. The symposium was organized such that papers concerning constituents--fibers and matrices--were presented first, followed by composite processing, modeling of mechanical behavior, and thermomechanical testing. More stable reinforcements are necessary to enhance the performance and life of fiber-reinforced ceramic composites, and to ensure final acceptance of these materials for high-temperature applications. Encouraging results in the areas of polymer-derived SiC fibers and single crystal oxide filaments were given, suggesting composites with improved thermomechanical properties and stability will be realized in the near future. The significance of the fiber-matrix interface in the design and performance of these materials is evident. Numerous mechanical models to relate interface properties to composite behavior, and interpret test methods and data, were enthusiastically discussed. One issue of great concern for any advanced material for use in extreme environments is stability. This theme arose frequently throughout the symposium and was the topic of focus on the final day. Fifty nine papers have been processed separately for inclusion on the data base.

  17. Bridging Microstructure, Properties and Processing of Polymer Based Advanced Materials

    SciTech Connect

    Li, Dongsheng; Ahzi, Said; Khaleel, Mohammad A.

    2012-01-01

    This is a guest editorial for a special issue in Journal of Engineering Materials and Technology. The papers collected in this special issue emphasize significant challenges, current approaches and future strategies necessary to advance the development of polymer-based materials. They were partly presented at the symposium of 'Bridging microstructure, properties and processing of polymer based advanced materials' in the TMS 2011 annual conference meeting, which was held in San Diego, US, on Feb 28 to March 3, 2011. This symposium was organized by the Pacific Northwest National Laboratory (USA) and the Institute of Mechanics of Fluids and Solids of the University of Strasbourg (France). The organizers were D.S. Li, S. Ahzi, and M. Khaleel.

  18. High resolution computed tomography of advanced composite and ceramic materials

    NASA Technical Reports Server (NTRS)

    Yancey, R. N.; Klima, S. J.

    1991-01-01

    Advanced composite and ceramic materials are being developed for use in many new defense and commercial applications. In order to achieve the desired mechanical properties of these materials, the structural elements must be carefully analyzed and engineered. A study was conducted to evaluate the use of high resolution computed tomography (CT) as a macrostructural analysis tool for advanced composite and ceramic materials. Several samples were scanned using a laboratory high resolution CT scanner. Samples were also destructively analyzed at the locations of the scans and the nondestructive and destructive results were compared. The study provides useful information outlining the strengths and limitations of this technique and the prospects for further research in this area.

  19. Elevated Temperature Testing and Modeling of Advanced Toughened Ceramic Materials

    NASA Technical Reports Server (NTRS)

    Keith, Theo G.

    2005-01-01

    The purpose of this report is to provide a final report for the period of 12/1/03 through 11/30/04 for NASA Cooperative Agreement NCC3-776, entitled "Elevated Temperature Testing and Modeling of Advanced Toughened Ceramic Materials." During this final period, major efforts were focused on both the determination of mechanical properties of advanced ceramic materials and the development of mechanical test methodologies under several different programs of the NASA-Glenn. The important research activities made during this period are: 1. Mechanical properties evaluation of two gas-turbine grade silicon nitrides. 2) Mechanical testing for fuel-cell seal materials. 3) Mechanical properties evaluation of thermal barrier coatings and CFCCs and 4) Foreign object damage (FOD) testing.

  20. Advanced High-Temperature Engine Materials Technology Progresses

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The objective of the Advanced High Temperature Engine Materials Technology Program (HITEMP) is to generate technology for advanced materials and structural analysis that will increase fuel economy, improve reliability, extend life, and reduce operating costs for 21st century civil propulsion systems. The primary focus is on fan and compressor materials (polymer-matrix composites--PMC's), compressor and turbine materials (superalloys, and metal-matrix and intermetallic-matrix composites--MMC's and IMC's) and turbine materials (ceramic-matrix composites--CMC's). These advanced materials are being developed by in-house researchers and on grants and contracts. NASA considers this program to be a focused materials and structures research effort that builds on our base research programs and supports component-development projects. HITEMP is coordinated with the Advanced Subsonic Technology (AST) Program and the Department of Defense/NASA Integrated High-Performance Turbine Engine Technology (IHPTET) Program. Advanced materials and structures technologies from HITEMP may be used in these future applications. Recent technical accomplishments have not only improved the state-of-the-art but have wideranging applications to industry. A high-temperature thin-film strain gage was developed to measure both dynamic and static strain up to 1100 C (2000 F). The gage's unique feature is that it is minimally intrusive. This technology, which received a 1995 R&D 100 Award, has been transferred to AlliedSignal Engines, General Electric Company, and Ford Motor Company. Analytical models developed at the NASA Lewis Research Center were used to study Textron Specialty Materials' manufacturing process for titanium-matrix composite rings. Implementation of our recommendations on tooling and processing conditions resulted in the production of defect free rings. In the Lincoln Composites/AlliedSignal/Lewis cooperative program, a composite compressor case is being manufactured with a Lewis

  1. Institute for Advanced Materials at University of Louisville

    SciTech Connect

    Sunkara, Mahendra; Sumaneskara, Gamini; Starr, Thomas L; Willing, G A; Robert W, Cohn

    2009-10-29

    In this project, a university-wide, academic center has been established entitled Institute for Advanced Materials and Renewable Energy. In this institute, a comprehensive materials characterization facility has been established by co-locating several existing characterization equipment and acquiring several state of the art instrumentation such as field emission transmission electron microscope, scanning electron microscope, high resolution X-ray diffractometer, Particle Size Distribution/Zeta Potential measurement system, and Ultra-microtome for TEM specimen. In addition, a renewable energy conversion and storage research facility was also established by acquiring instrumentation such as UV-Vis absorption spectroscopy, Atomic Layer Deposition reactor, Solar light simulator, oxygen-free glove box, potentiostat/galvanostats and other miscellaneous items. The institute is staffed with three full-time staff members (one senior research technologist, a senior PhD level research scientist and a junior research scientist) to enable proper use of the techniques. About thirty faculty, fifty graduate students and several researchers access the facilities on a routine basis. Several industry R&D organizations (SudChemie, Optical Dynamics and Hexion) utilize the facility. The established Institute for Advanced Materials at UofL has three main objectives: (a) enable a focused research effort leading to the rapid discovery of new materials and processes for advancing alternate energy conversion and storage technologies; (b) enable offering of several laboratory courses on advanced materials science and engineering; and (c) develop university-industry partnerships based on the advanced materials research. The Institute's efforts were guided by an advisory board comprising eminent researchers from outside KY. Initial research efforts were focused on the discovery of new materials and processes for solar cells and Li ion battery electrodes. Initial sets of results helped PIs to

  2. PREFACE: 7th EEIGM International Conference on Advanced Materials Research

    NASA Astrophysics Data System (ADS)

    Joffe, Roberts

    2013-12-01

    The 7th EEIGM Conference on Advanced Materials Research (AMR 2013) was held at Luleå University of Technology on the 21-22 March 2013 in Luleå, SWEDEN. This conference is intended as a meeting place for researchers involved in the EEIGM programme, in the 'Erasmus Mundus' Advanced Materials Science and Engineering Master programme (AMASE) and the 'Erasmus Mundus' Doctoral Programme in Materials Science and Engineering (DocMASE). This is great opportunity to present their on-going research in the various fields of Materials Science and Engineering, exchange ideas, strengthen co-operation as well as establish new contacts. More than 60 participants representing six countries attended the meeting, in total 26 oral talks and 19 posters were presented during two days. This issue of IOP Conference Series: Materials Science and Engineering presents a selection of articles from EEIGM-7 conference. Following tradition from previous EEIGM conferences, it represents the interdisciplinary nature of Materials Science and Engineering. The papers presented in this issue deal not only with basic research but also with applied problems of materials science. The presented topics include theoretical and experimental investigations on polymer composite materials (synthetic and bio-based), metallic materials and ceramics, as well as nano-materials of different kind. Special thanks should be directed to the senior staff of Division of Materials Science at LTU who agreed to review submitted papers and thus ensured high scientific level of content of this collection of papers. The following colleagues participated in the review process: Professor Lennart Walström, Professor Roberts Joffe, Professor Janis Varna, Associate Professor Marta-Lena Antti, Dr Esa Vuorinen, Professor Aji Mathew, Professor Alexander Soldatov, Dr Andrejs Purpurs, Dr Yvonne Aitomäki, Dr Robert Pederson. Roberts Joffe October 2013, Luleå Conference photograph EEIGM7 conference participants, 22 March 2013 The PDF

  3. PREFACE: Functional materials and nanotechnologies (FM&NT-2007)

    NASA Astrophysics Data System (ADS)

    Sternberg, Andris; Muzikante, Inta

    2007-06-01

    The International Baltic Sea Region conference Functional Materials and Nanotechnologies (FM&NT-2007) was held in Riga, 2-4 April 2007 in the Institute of Solid State Physics, University of Latvia (ISSP LU). The conference was organized in co-operation with projects ERANET 'MATERA' and EUREKA 'BIONANOCOMPOSITE'. The purpose of the conference was to bring together scientists, engineers and students from universities, research institutes and related industrial companies active in the field of advanced material science and materials technologies trends and future activities. Scientific themes covered in the conference are:

  4. advanced inorganic materials for photonics, energetics and microelectronics
  5. organic materials for photonics and nanoelectronics
  6. advanced methods for investigation of nanostructures
  7. perspective biomaterials and medicine technologies
  8. development of technologies for design of nanostructured materials, nanoparticles, and thin films
  9. design of functional materials and nanocomposites and development of their technologies
  10. The number of registered participants from 14 countries was nearly 110. During three days of the conference 70 oral reports and 58 posters were presented, 50 papers, based on these reports, are included in this volume of Journal of Physics: Conference Series. Additional information about FM&NT-2007 is available in its homepage http://fmnt.lu.lv and http://www.fmnt.lv . The Organizing Committee would like to thank all speakers, contributors, session chairs, referees and meeting staff for their efforts in making the FM&NT-2007 successful. The local Organization Committee would like to acknowledge and thank our sponsors - Latvian Council of Science and the Institute of Solid State Physics, University of Latvia. Andris Sternberg Inta Muzikante Guest editors

  11. Materials and Component Development for Advanced Turbine Systems

    SciTech Connect

    Alvin, M.A.; Pettit, F.; Meier, G.; Yanar, N.; Chyu, M.; Mazzotta, D.; Slaughter, W.; Karaivanov, V.; Kang, B.; Feng, C.; Chen, R.; Fu, T-C.

    2008-10-01

    In order to meet the 2010-2020 DOE Fossil Energy goals for Advanced Power Systems, future oxy-fuel and hydrogen-fired turbines will need to be operated at higher temperatures for extended periods of time, in environments that contain substantially higher moisture concentrations in comparison to current commercial natural gas-fired turbines. Development of modified or advanced material systems, combined with aerothermal concepts are currently being addressed in order to achieve successful operation of these land-based engines. To support the advanced turbine technology development, the National Energy Technology Laboratory (NETL) has initiated a research program effort in collaboration with the University of Pittsburgh (UPitt), and West Virginia University (WVU), working in conjunction with commercial material and coating suppliers as Howmet International and Coatings for Industry (CFI), and test facilities as Westinghouse Plasma Corporation (WPC) and Praxair, to develop advanced material and aerothermal technologies for use in future oxy-fuel and hydrogen-fired turbine applications. Our program efforts and recent results are presented.

  12. Synthesis and characterization of advanced materials for Navy applications

    SciTech Connect

    Covino, J.

    1993-12-31

    This paper addresses the synthesis of ceramics and ceramic coatings, via the sol-gel process for use in specific Navy applications. Among the specific applications are: coatings for electrocromic devices; laser gyro bodies, hermetic coatings for optical fibers for use in ocean environments; coating development for advanced light weight structural applications; and incorporation of organic and inorganic dyes in silica based ceramics for laser applications. It will also address the characterization of these systems as well as advanced structural materials with respect to durability, chemical stability, optical properties and other properties which are more specific to their applications and end use.

  13. PREFACE: 6th EEIGM International Conference on Advanced Materials Research

    NASA Astrophysics Data System (ADS)

    Horwat, David; Ayadi, Zoubir; Jamart, Brigitte

    2012-02-01

    The 6th EEIGM Conference on Advanced Materials Research (AMR 2011) was held at the European School of Materials Engineering (EEIGM) on the 7-8 November 2011 in Nancy, France. This biennial conference organized by the EEIGM is a wonderful opportunity for all scientists involved in the EEIGM programme, in the 'Erasmus Mundus' Advanced Materials Science and Engineering Master programme (AMASE) and the 'Erasmus Mundus' Doctoral Programme in Materials Science and Engineering (DocMASE), to present their research in the various fields of Materials Science and Engineering. This conference is also open to other universities who have strong links with the EEIGM and provides a forum for the exchange of ideas, co-operation and future orientations by means of regular presentations, posters and a round-table discussion. This edition of the conference included a round-table discussion on composite materials within the Interreg IVA project '+Composite'. Following the publication of the proceedings of AMR 2009 in Volume 5 of this journal, it is with great pleasure that we present this selection of articles to the readers of IOP Conference Series: Materials Science and Engineering. Once again it represents the interdisciplinary nature of Materials Science and Engineering, covering basic and applicative research on organic and composite materials, metallic materials and ceramics, and characterization methods. The editors are indebted to all the reviewers for reviewing the papers at very short notice. Special thanks are offered to the sponsors of the conference including EEIGM-Université de Lorraine, AMASE, DocMASE, Grand Nancy, Ville de Nancy, Region Lorraine, Fédération Jacques Villermaux, Conseil Général de Meurthe et Moselle, Casden and '+Composite'. Zoubir Ayadi, David Horwat and Brigitte Jamart

  14. Advanced Electrical Materials and Components Development: An Update

    NASA Technical Reports Server (NTRS)

    Schwarze, Gene E.

    2005-01-01

    The primary means to develop advanced electrical components is to develop new and improved materials for magnetic components (transformers, inductors, etc.), capacitors, and semiconductor switches and diodes. This paper will give an update of the Advanced Power Electronics and Components Technology being developed by the NASA Glenn Research Center for use in future Power Management and Distribution subsystems used in space power systems for spacecraft and lunar and planetary surface power. The initial description and status of this technology program was presented two years ago at the First International Energy Conversion Engineering Conference held at Portsmouth, Virginia, August 2003. The present paper will give a brief background of the previous work reported and a summary of research performed the past several years on soft magnetic materials characterization, dielectric materials and capacitor developments, high quality silicon carbide atomically smooth substrates, and SiC static and dynamic device characterization under elevated temperature conditions. The rationale for and the benefits of developing advanced electrical materials and components for the PMAD subsystem and also for the total power system will also be briefly discussed.

  15. PREFACE: 4th International Symposium on Functional Materials (ISFM2011)

    NASA Astrophysics Data System (ADS)

    Yin, Shu; Sekino, Tohru; Tanaka, Shun-ichiro; Sato, Tsugio; Lu, Li; Xue, Dongfeng

    2012-01-01

    The 4th International Symposium on Functional Materials (ISFM2011) was held in Sendai, Japan, on 2-6 August 2011. This Special Issue of Journal of Physics: Conference Series (JPCS) consists of partial manuscripts which were presented at ISFM2011. Advanced materials have experienced a dramatic increase in demand for research, development and applications. The aim of the International Symposium on Functional Materials (ISFM) was to provide an overview of the present status with historical background and to foresee future trends in the field of functional materials. The 4th symposium, ISFM 2011, covered a wide variety of topics within state-of-the-art advanced materials science and technology, and focused especially on four major categories including: Environmental Materials, Electronic Materials, Energy Materials and Biomedical Materials. As you know, a massive earthquake and the Tsunami that followed occurred near the Tohoku region on 11 March 2011. After the earthquake, although there were many difficulties in continuing to organize the symposium, we received warm encouragement from many researchers and societies, especially from the members of the International Advisory Committee and Organizing Committee, so that ISFM2011 could be held on schedule. We are honored that ISFM2011 was the first formal international academic conference held in the Tohoku area of Japan after the 11 March earthquake. About 140 participants from 14 countries took part in the ISFM2011 symposium, which included five plenary talks by world-leading scientists, 32 invited talks, and many oral and poster presentations. We are delighted to see that many researchers are interested in the synthesis and the properties as well as the applications of functional materials. Many fruitful and exciting research achievements were presented in the symposium. We believe that this symposium provided a good chance for scientists to communicate and exchange opinions with each other. We would also like to

  16. Report on sodium compatibility of advanced structural materials.

    SciTech Connect

    Li, M.; Natesan, K.; Momozaki, Y.; Rink, D.L.; Soppet, W.K.; Listwan, J.T.

    2012-07-09

    This report provides an update on the evaluation of sodium compatibility of advanced structural materials. The report is a deliverable (level 3) in FY11 (M3A11AN04030403), under the Work Package A-11AN040304, 'Sodium Compatibility of Advanced Structural Materials' performed by Argonne National Laboratory (ANL), as part of Advanced Structural Materials Program for the Advanced Reactor Concepts. This work package supports the advanced structural materials development by providing corrosion and tensile data from the standpoint of sodium compatibility of advanced structural alloys. The scope of work involves exposure of advanced structural alloys such as G92, mod.9Cr-1Mo (G91) ferritic-martensitic steels and HT-UPS austenitic stainless steels to a flowing sodium environment with controlled impurity concentrations. The exposed specimens are analyzed for their corrosion performance, microstructural changes, and tensile behavior. Previous reports examined the thermodynamic and kinetic factors involved in the purity of liquid sodium coolant for sodium reactor applications as well as the design, fabrication, and construction of a forced convection sodium loop for sodium compatibility studies of advanced materials. This report presents the results on corrosion performance, microstructure, and tensile properties of advanced ferritic-martensitic and austenitic alloys exposed to liquid sodium at 550 C for up to 2700 h and at 650 C for up to 5064 h in the forced convection sodium loop. The oxygen content of sodium was controlled by the cold-trapping method to achieve {approx}1 wppm oxygen level. Four alloys were examined, G92 in the normalized and tempered condition (H1 G92), G92 in the cold-rolled condition (H2 G92), G91 in the normalized and tempered condition, and hot-rolled HT-UPS. G91 was included as a reference to compare with advanced alloy, G92. It was found that all four alloys showed weight loss after sodium exposures at 550 and 650 C. The weight loss of the four

  17. Technology Readiness Levels for Advanced Nuclear Fuels and Materials Development

    SciTech Connect

    Jon Carmack

    2014-01-01

    The Technology Readiness Level (TRL) process is used to quantitatively assess the maturity of a given technology. The TRL process has been developed and successfully used by the Department of Defense (DOD) for development and deployment of new technology and systems for defense applications. In addition, NASA has also successfully used the TRL process to develop and deploy new systems for space applications. Advanced nuclear fuels and materials development is a critical technology needed for closing the nuclear fuel cycle. Because the deployment of a new nuclear fuel forms requires a lengthy and expensive research, development, and demonstration program, applying the TRL concept to the advanced fuel development program is very useful as a management and tracking tool. This report provides definition of the technology readiness level assessment process as defined for use in assessing nuclear fuel technology development for the Advanced Fuel Campaign (AFC).

  18. Polymers as advanced materials for desiccant applications, 1988

    SciTech Connect

    Czanderna, A.W.; Neidlinger, H.H.

    1990-09-01

    This report documents work to identify a next-generation, low-cost material with which solar energy or heat from another low-cost energy source can be used for regenerating the water vapor sorption activity of the desiccant. The objective of the work is to determine how the desired sorption performance of advanced desiccant materials can be predicted by understanding the role of the material modifications and material surfaces. The work concentrates on solid materials to be used for desiccant cooling systems and which process water vapor in an atmosphere to produce cooling. The work involved preparing modifications of polystyrene sulfonic acid sodium salt, synthesizing a hydrogel, and evaluating the sorption performances of these and similar commercially available polymeric materials; all materials were studied for their potential application in solid commercial desiccant cooling systems. Background information is also provided on desiccant cooling systems and the role of a desiccant material within such a system, and it includes the use of polymers as desiccant materials. 31 refs., 16 figs., 5 tabs.

  19. Preface: Special Topic on Advances in Density Functional Theory

    SciTech Connect

    Yang, Weitao

    2014-05-14

    This Special Topic Issue on the Advances in Density Functional Theory, published as a celebration of the fifty years of density functional theory, contains a retrospective article, a perspective article, and a collection of original research articles that showcase recent theoretical advances in the field. It provides a timely discussion reflecting a cross section of our understanding, and the theoretical and computational developments, which have significant implications in broad areas of sciences and engineering.

  20. Preface: Special topic on advances in density functional theory.

    PubMed

    Yang, Weitao

    2014-05-14

    This Special Topic Issue on the Advances in Density Functional Theory, published as a celebration of the fifty years of density functional theory, contains a retrospective article, a perspective article, and a collection of original research articles that showcase recent theoretical advances in the field. It provides a timely discussion reflecting a cross section of our understanding, and the theoretical and computational developments, which have significant implications in broad areas of sciences and engineering. PMID:24832306

  21. Corrosion performance of materials for advanced combustion systems

    SciTech Connect

    Natesan, K.; Yanez-Herrero, M.; Fornasieri, C.

    1993-12-01

    Conceptual designs of advanced combustion systems that utilize coal as a feedstock require high-temperature furnaces and heat transfer surfaces capable of operating at more elevated temperatures than those prevalent in current coal-fired power plants. The combination of elevated temperatures and hostile combustion environments necessitates development/application of advanced ceramic materials in these designs. This report characterizes the chemistry of coal-fired combustion environments over the wide temperature range that is of interest in these systems and discusses preliminary experimental results on several materials (alumina, Hexoloy, SiC/SiC, SiC/Si{sub 3}N{sub 4}/Si{sub 3}N{sub 4}, ZIRCONIA, INCONEL 677 and 617) with potential for application in these systems.

  22. Mishap risk control for advanced aerospace/composite materials

    NASA Technical Reports Server (NTRS)

    Olson, John M.

    1994-01-01

    Although advanced aerospace materials and advanced composites provide outstanding performance, they also present several unique post-mishap environmental, safety, and health concerns. The purpose of this paper is to provide information on some of the unique hazards and concerns associated with these materials when damaged by fire, explosion, or high-energy impact. Additionally, recommended procedures and precautions are addressed as they pertain to all phases of a composite aircraft mishap response, including fire-fighting, investigation, recovery, clean-up, and guidelines are general in nature and not application-specific. The goal of this project is to provide factual and realistic information which can be used to develop consistent and effective procedures and policies to minimize the potential environmental, safety, and health impacts of a composite aircraft mishap response effort.

  23. Analytical Model for Thermal Elastoplastic Stresses of Functionally Graded Materials

    SciTech Connect

    Zhai, P. C.; Chen, G.; Liu, L. S.; Fang, C.; Zhang, Q. J.

    2008-02-15

    A modification analytical model is presented for the thermal elastoplastic stresses of functionally graded materials subjected to thermal loading. The presented model follows the analytical scheme presented by Y. L. Shen and S. Suresh [6]. In the present model, the functionally graded materials are considered as multilayered materials. Each layer consists of metal and ceramic with different volume fraction. The ceramic layer and the FGM interlayers are considered as elastic brittle materials. The metal layer is considered as elastic-perfectly plastic ductile materials. Closed-form solutions for different characteristic temperature for thermal loading are presented as a function of the structure geometries and the thermomechanical properties of the materials. A main advance of the present model is that the possibility of the initial and spread of plasticity from the two sides of the ductile layers taken into account. Comparing the analytical results with the results from the finite element analysis, the thermal stresses and deformation from the present model are in good agreement with the numerical ones.

  24. A combinatorial approach to the discovery of advanced materials

    NASA Astrophysics Data System (ADS)

    Sun, Xiao-Dong

    This thesis discusses the application of combinatorial methods to the search of advanced materials. The goal of this research is to develop a "parallel" or "fast sequential" methodology for both the synthesis and characterization of materials with novel electronic, magnetic and optical properties. Our hope is to dramatically accelerate the rate at which materials are generated and studied. We have developed two major combinatorial methodologies to this end. One involves generating thin film materials libraries using a combination of various thin film deposition and masking strategies with multi-layer thin film precursors. The second approach is to generate powder materials libraries with solution precursors delivered with a multi-nozzle inkjet system. The first step in this multistep combinatorial process involves the design and synthesis of high density libraries of diverse materials aimed at exploring a large segment of the compositional space of interest based on our understanding of the physical and structural properties of a particular class of materials. Rapid, sensitive measurements of one or more relevant physical properties of each library member result in the identification of a family of "lead" compositions with a desired property. These compositions are then optimized by continuously varying the stoichiometries of a more focused set of precursors. Materials with the optimal composition are then synthesized in quantities sufficient for detailed characterization of their structural and physical properties. Finally, the information obtained from this process should enhance our predictive ability in subsequent experiments. Combinatorial methods have been successfully used in the synthesis and discovery of materials with novel properties. For example, a class of cobaltite based giant magnetoresistance (GMR) ceramics was discovered; Application of this method to luminescence materials has resulted in the discovery of a few highly efficient tricolor

  25. Silicon as an advanced window material for high power gyrotrons

    SciTech Connect

    Parshin, V.V.; Andreev, B.A.; Gusev, A.V.

    1995-05-01

    The absorptivity of high-purity grades of silicon (Si) and its reduction by subsequent doping procedures are investigated. The dielectric data are given for the wide range of frequencies (30 -330 GHz) and temperatures (30 -330 K) in comparison with the data set for sapphire. The advanced material performance in high power window applications is discussed taking into account both dielectric properties of the optimized silicon grades and thermal conductivity.

  26. ADVANCED HOT SECTION MATERIALS AND COATINGS TEST RIG

    SciTech Connect

    Scott Reome; Dan Davies

    2004-01-01

    The Hyperbaric Advanced Hot Section Materials & Coating Test Rig program initiated this quarter, provides design and implementation of a laboratory rig capable of simulating the hot gas path conditions of coal-gas fired industrial gas turbine engines. The principle activity during this first reporting period were preparing for and conducting a project kick-off meeting, working through plans for the project implementation, and beginning the conceptual design of the test section.

  27. Materials Advances to Enhance Development of Geothermal Power

    SciTech Connect

    Kukacka, Lawrence E.

    1989-03-21

    In order to assure the continued development of geothermal resources, many advances in materials technology are required so that high costs resulting from the severe environments encountered during drilling, well completion and energy extraction can be reduced. These needs will become more acute as higher temperature and chemically aggressive fluids are encountered. High priority needs are for lost circulation control and lightweight well completion materials, and tools such as drill pipe protectors, rotating head seals, blow-out preventers, and downhole drill motors. The lack of suitable hydrolytically stable chemical systems that can bond previously developed elastomers to metal reinforcement is a critical but as yet unaddressed impediment to the development of these tools. In addition, the availability of low cost corrosion and scale-resistant tubular lining materials would greatly enhance transport and energy extraction processes utilizing hypersaline brines. Work to address these materials needs is underway at Brookhaven National Laboratory (BNL), and recent accomplishments are summarized in the paper.

  1. ADVANCED ELECTRIC AND MAGNETIC MATERIAL MODELS FOR FDTD ELECTROMAGNETIC CODES

    SciTech Connect

    Poole, B R; Nelson, S D; Langdon, S

    2005-05-05

    The modeling of dielectric and magnetic materials in the time domain is required for pulse power applications, pulsed induction accelerators, and advanced transmission lines. For example, most induction accelerator modules require the use of magnetic materials to provide adequate Volt-sec during the acceleration pulse. These models require hysteresis and saturation to simulate the saturation wavefront in a multipulse environment. In high voltage transmission line applications such as shock or soliton lines the dielectric is operating in a highly nonlinear regime, which require nonlinear models. Simple 1-D models are developed for fast parameterization of transmission line structures. In the case of nonlinear dielectrics, a simple analytic model describing the permittivity in terms of electric field is used in a 3-D finite difference time domain code (FDTD). In the case of magnetic materials, both rate independent and rate dependent Hodgdon magnetic material models have been implemented into 3-D FDTD codes and 1-D codes.

  2. [Advances of poly (ionic liquid) materials in separation science].

    PubMed

    Liu, Cuicui; Guo, Ting; Su, Rina; Gu, Yuchen; Deng, Qiliang

    2015-11-01

    Ionic liquids, as novel ionization reagents, possess beneficial characteristics including good solubility, conductivity, thermal stability, biocompatibility, low volatility and non-flammability. Ionic liquids are attracting a mass of attention of analytical chemists. Poly (ionic liquid) materials have common performances of ionic liquids and polymers, and have been successfully applied in separation science area. In this paper, we discuss the interaction mechanisms between the poly(ionic liquid) materials and analytes including hydrophobic/hydrophilic interactions, hydrogen bond, ion exchange, π-π stacking and electrostatic interactions, and summarize the application advances of the poly(ionic liquid) materials in solid phase extraction, chromatographic separation and capillary electrophoresis. At last, we describe the future prospect of poly(ionic liquid) materials. PMID:26939357

  3. Ultrasonic and radiographic evaluation of advanced aerospace materials: Ceramic composites

    NASA Technical Reports Server (NTRS)

    Generazio, Edward R.

    1990-01-01

    Two conventional nondestructive evaluation techniques were used to evaluate advanced ceramic composite materials. It was shown that neither ultrasonic C-scan nor radiographic imaging can individually provide sufficient data for an accurate nondestructive evaluation. Both ultrasonic C-scan and conventional radiographic imaging are required for preliminary evaluation of these complex systems. The material variations that were identified by these two techniques are porosity, delaminations, bond quality between laminae, fiber alignment, fiber registration, fiber parallelism, and processing density flaws. The degree of bonding between fiber and matrix cannot be determined by either of these methods. An alternative ultrasonic technique, angular power spectrum scanning (APSS) is recommended for quantification of this interfacial bond.

  4. Advanced materials and biochemical processes for geothermal applications

    SciTech Connect

    Kukacka, L.E.; van Rooyen, D.; Premuzic, E.T.

    1987-04-01

    Two Geothermal Technology Division (GTD)-sponsored programs: (1) Geothermal Materials Development, and (2) Advanced Biochemical Processes for Geothermal Brines, are described. In the former, work in the following tasks is in progress: (1) high temperature elastomeric materials for dynamic sealing applications, (2) advanced high temperature (300/sup 0/C) lightweight (1.1 g/cc) well cementing materials, (3) thermally conductive composites for heat exchanger tubing, (4) corrosion rates for metals in brine-contaminated binary plant working fluids, and (5) elastomeric liners for well casing. Methods for the utilization and/or the low cost environmentally acceptable disposal of toxic geothermal residues are being developed in the second program. This work is performed in two tasks. In one, microorganisms that can interact with toxic metals found in geothermal residues to convert them into soluble species for subsequent reinjection back into the reservoir or to concentrate them for removal by conventional processes are being identified. In the second task, process conditions are being defined for the encapsulation of untreated or partially biochemically treated residues in Portland cement-based formulations and the subsequent utilization of the waste fractions in building materials. Both processing methods yield materials which appear to meet disposal criteria for non-toxic solid waste, and their technical and economic feasibilities have been established.

  5. Sol-gel Technology and Advanced Electrochemical Energy Storage Materials

    NASA Technical Reports Server (NTRS)

    Chu, Chung-tse; Zheng, Haixing

    1996-01-01

    Advanced materials play an important role in the development of electrochemical energy devices such as batteries, fuel cells, and electrochemical capacitors. The sol-gel process is a versatile solution for use in the fabrication of ceramic materials with tailored stoichiometry, microstructure, and properties. This processing technique is particularly useful in producing porous materials with high surface area and low density, two of the most desirable characteristics for electrode materials. In addition,the porous surface of gels can be modified chemically to create tailored surface properties, and inorganic/organic micro-composites can be prepared for improved material performance device fabrication. Applications of several sol-gel derived electrode materials in different energy storage devices are illustrated in this paper. V2O5 gels are shown to be a promising cathode material for solid state lithium batteries. Carbon aerogels, amorphous RuO2 gels and sol-gel derived hafnium compounds have been studied as electrode materials for high energy density and high power density electrochemical capacitors.

  6. Prediction of Corrosion of Advanced Materials and Fabricated Components

    SciTech Connect

    A. Anderko; G. Engelhardt; M.M. Lencka; M.A. Jakab; G. Tormoen; N. Sridhar

    2007-09-29

    The goal of this project is to provide materials engineers, chemical engineers and plant operators with a software tool that will enable them to predict localized corrosion of process equipment including fabricated components as well as base alloys. For design and revamp purposes, the software predicts the occurrence of localized corrosion as a function of environment chemistry and assists the user in selecting the optimum alloy for a given environment. For the operation of existing plants, the software enables the users to predict the remaining life of equipment and help in scheduling maintenance activities. This project combined fundamental understanding of mechanisms of corrosion with focused experimental results to predict the corrosion of advanced, base or fabricated, alloys in real-world environments encountered in the chemical industry. At the heart of this approach is the development of models that predict the fundamental parameters that control the occurrence of localized corrosion as a function of environmental conditions and alloy composition. The fundamental parameters that dictate the occurrence of localized corrosion are the corrosion and repassivation potentials. The program team, OLI Systems and Southwest Research Institute, has developed theoretical models for these parameters. These theoretical models have been applied to predict the occurrence of localized corrosion of base materials and heat-treated components in a variety of environments containing aggressive and non-aggressive species. As a result of this project, a comprehensive model has been established and extensively verified for predicting the occurrence of localized corrosion as a function of environment chemistry and temperature by calculating the corrosion and repassivation potentials.To support and calibrate the model, an experimental database has been developed to elucidate (1) the effects of various inhibiting species as well as aggressive species on localized corrosion of nickel

  7. Modeling Bamboo as a Functionally Graded Material

    SciTech Connect

    Silva, Emilio Carlos Nelli; Walters, Matthew C.; Paulino, Glaucio H.

    2008-02-15

    Natural fibers are promising for engineering applications due to their low cost. They are abundantly available in tropical and subtropical regions of the world, and they can be employed as construction materials. Among natural fibers, bamboo has been widely used for housing construction around the world. Bamboo is an optimized composite material which exploits the concept of Functionally Graded Material (FGM). Biological structures, such as bamboo, are composite materials that have complicated shapes and material distribution inside their domain, and thus the use of numerical methods such as the finite element method and multiscale methods such as homogenization, can help to further understanding of the mechanical behavior of these materials. The objective of this work is to explore techniques such as the finite element method and homogenization to investigate the structural behavior of bamboo. The finite element formulation uses graded finite elements to capture the varying material distribution through the bamboo wall. To observe bamboo behavior under applied loads, simulations are conducted considering a spatially-varying Young's modulus, an averaged Young's modulus, and orthotropic constitutive properties obtained from homogenization theory. The homogenization procedure uses effective, axisymmetric properties estimated from the spatially-varying bamboo composite. Three-dimensional models of bamboo cells were built and simulated under tension, torsion, and bending load cases.

  8. Advanced thermoplastic materials for district heating piping systems

    SciTech Connect

    Raske, D.T.; Karvelas, D.E.

    1988-04-01

    The work described in this report represents research conducted in the first year of a three-year program to assess, characterize, and design thermoplastic piping for use in elevated-temperature district heating (DH) systems. The present report describes the results of a program to assess the potential usefulness of advanced thermoplastics as piping materials for use in DH systems. This includes the review of design rules for thermoplastic materials used as pipes, a survey of candidate materials and available mechanical properties data, and mechanical properties testing to obtain baseline data on a candidate thermoplastic material extruded as pipe. The candidate material studied in this phase of the research was a polyetherimide resin, Ultem 1000, which has a UL continuous service temperature rating of 338/degree/F (170/degree/C). The results of experiments to determine the mechanical properties between 68 and 350/degree/F (20 and 177/degree/C) were used to establish preliminary design values for this material. Because these prototypic pipes were extruded under less than optimal conditions, the mechanical properties obtained are inferior to those expected from typical production pipes. Nevertheless, the present material in the form of 2-in. SDR 11 pipe (2.375-in. O. D. by 0.216-in. wall) would have a saturated water design pressure rating of /approximately/34 psig at 280/degree/F. 16 refs., 6 figs., 8 tabs.

  9. Advanced composite structural concepts and materials technologies for primary aircraft structures: Advanced material concepts

    NASA Technical Reports Server (NTRS)

    Lau, Kreisler S. Y.; Landis, Abraham L.; Chow, Andrea W.; Hamlin, Richard D.

    1993-01-01

    To achieve acceptable performance and long-term durability at elevated temperatures (350 to 600 F) for high-speed transport systems, further improvements of the high-performance matrix materials will be necessary to achieve very long-term (60,000-120,000 service hours) retention of mechanical properties and damage tolerance. This report emphasizes isoimide modification as a complementary technique to semi-interpenetrating polymer networks (SIPN's) to achieve greater processibility, better curing dynamics, and possibly enhanced thermo-mechanical properties in composites. A key result is the demonstration of enhanced processibility of isoimide-modified linear and thermo-setting polyimide systems.

  10. Crystallization of Oxides as Functional Materials

    NASA Astrophysics Data System (ADS)

    Sun, Congting; Song, Shuyan; Xue, Dongfeng; Zhang, Hongjie

    2012-06-01

    Crystallization is essential to the manufacture of functional materials as varies as electronic devices, energy storage and conversion devices, and highly reactive catalysts. As an important part of functional materials, metal oxides possess wide applications and the crystallization of oxide materials has thus received considerable attention from both fundamental and technological perspectives. With particular emphasis on our recent laboratory results, this feature article gives a brief review in the field of crystallization of oxides. On the basis of chemical bonding theory of single crystal growth, we have simulated thermodynamic growth behaviors of various functional oxides such as ZnO, MgO, Cu2O, Nb2O5, V2O5, MnO2, SnO2, NiO, KDP/ADP, LiNbO3, and NaNbO3. Quantitatively analyzing bonding conditions of controllable crystallographic faces enables us to design proper synthesis strategies and optimize growth parameters, consequently obtaining functional oxides with desirable crystallization behaviors.

  11. Area Reports. Advanced materials and devices research area. Silicon materials research task, and advanced silicon sheet task

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The objectives of the Silicon Materials Task and the Advanced Silicon Sheet Task are to identify the critical technical barriers to low-cost silicon purification and sheet growth that must be overcome to produce a PV cell substrate material at a price consistent with Flat-plate Solar Array (FSA) Project objectives and to overcome these barriers by performing and supporting appropriate R&D. Progress reports are given on silicon refinement using silane, a chemical vapor transport process for purifying metallurgical grade silicon, silicon particle growth research, and modeling of silane pyrolysis in fluidized-bed reactors.

  12. Thermal Characterization of Nanostructures and Advanced Engineered Materials

    NASA Astrophysics Data System (ADS)

    Goyal, Vivek Kumar

    to heat-sinking units. This dissertation presents results of the experimental investigation and theoretical interpretation of thermal transport in the advanced engineered materials, which include thin films for thermal management of nanoscale devices, nanostructured superlattices as promising candidates for high-efficiency thermoelectric materials, and improved TIMs with graphene and metal particles as fillers providing enhanced thermal conductivity. The advanced engineered materials studied include chemical vapor deposition (CVD) grown ultrananocrystalline diamond (UNCD) and microcrystalline diamond (MCD) films on Si substrates, directly integrated nanocrystalline diamond (NCD) films on GaN, free-standing polycrystalline graphene (PCG) films, graphene oxide (GOx) films, and "pseudo-superlattices" of the mechanically exfoliated Bi2Te3 topological insulator films, and thermal interface materials (TIMs) with graphene fillers.

  13. Advanced Materials for Mercury 50 Gas Turbine Combustion System

    SciTech Connect

    Price, Jeffrey

    2008-09-30

    Solar Turbines Incorporated (Solar), under cooperative agreement number DE-FC26-0CH11049, has conducted development activities to improve the durability of the Mercury 50 combustion system to 30,000 hours life and reduced life cycle costs. This project is part of Advanced Materials in the Advanced Industrial Gas Turbines program in DOE's Office of Distributed Energy. The targeted development engine was the Mercury{trademark} 50 gas turbine, which was developed by Solar under the DOE Advanced Turbine Systems program (DOE contract number DE-FC21-95MC31173). As a generator set, the Mercury 50 is used for distributed power and combined heat and power generation and is designed to achieve 38.5% electrical efficiency, reduced cost of electricity, and single digit emissions. The original program goal was 20,000 hours life, however, this goal was increased to be consistent with Solar's standard 30,000 hour time before overhaul for production engines. Through changes to the combustor design to incorporate effusion cooling in the Generation 3 Mercury 50 engine, which resulted in a drop in the combustor wall temperature, the current standard thermal barrier coated liner was predicted to have 18,000 hours life. With the addition of the advanced materials technology being evaluated under this program, the combustor life is predicted to be over 30,000 hours. The ultimate goal of the program was to demonstrate a fully integrated Mercury 50 combustion system, modified with advanced materials technologies, at a host site for a minimum of 4,000 hours. Solar was the Prime Contractor on the program team, which includes participation of other gas turbine manufacturers, various advanced material and coating suppliers, nationally recognized test laboratories, and multiple industrial end-user field demonstration sites. The program focused on a dual path development route to define an optimum mix of technologies for the Mercury 50 and future gas turbine products. For liner and injector

  14. Materials Advances for Next-Generation Ingestible Electronic Medical Devices.

    PubMed

    Bettinger, Christopher J

    2015-10-01

    Electronic medical implants have collectively transformed the diagnosis and treatment of many diseases, but have many inherent limitations. Electronic implants require invasive surgeries, operate in challenging microenvironments, and are susceptible to bacterial infection and persistent inflammation. Novel materials and nonconventional device fabrication strategies may revolutionize the way electronic devices are integrated with the body. Ingestible electronic devices offer many advantages compared with implantable counterparts that may improve the diagnosis and treatment of pathologies ranging from gastrointestinal infections to diabetes. This review summarizes current technologies and highlights recent materials advances. Specific focus is dedicated to next-generation materials for packaging, circuit design, and on-board power supplies that are benign, nontoxic, and even biodegradable. Future challenges and opportunities are also highlighted. PMID:26403162

  15. Testing of Alternative Materials for Advanced Suit Bladders

    NASA Technical Reports Server (NTRS)

    Bue, Grant; Orndoff, Evelyne; Makinen, Janice; Tang, Henry

    2011-01-01

    Several candidate advanced pressure bladder membrane materials have been developed for NASA Johnson Space Center by DSM Biomedical for selective permeability of carbon dioxide and water vapor. These materials were elasthane and two other formulations of thermoplastic polyether polyurethane. Each material was tested in two thicknesses for permeability to carbon dioxide, oxygen and water vapor. Although oxygen leaks through the suit bladder would amount to only about 60 cc/hr in a full size suit, significant amounts of carbon dioxide would not be rejected by the system to justify its use. While the ratio of carbon dioxide to oxygen permeability is about 48 to 1, this is offset by the small partial pressure of carbon dioxide in acceptable breathing atmospheres of the suit. Humidity management remains a possible use of the membranes depending on the degree to which the water permeability is inhibited by cations in the sweat. Tests are underway to explore cation fouling from sweat.

  16. Development of processing techniques for advanced thermal protection materials

    NASA Technical Reports Server (NTRS)

    Selvaduray, Guna S.

    1994-01-01

    The effort, which was focused on the research and development of advanced materials for use in Thermal Protection Systems (TPS), has involved chemical and physical testing of refractory ceramic tiles, fabrics, threads and fibers. This testing has included determination of the optical properties, thermal shock resistance, high temperature dimensional stability, and tolerance to environmental stresses. Materials have also been tested in the Arc Jet 2 x 9 Turbulent Duct Facility (TDF), the 1 atmosphere Radiant Heat Cycler, and the Mini-Wind Tunnel Facility (MWTF). A significant part of the effort hitherto has gone towards modifying and upgrading the test facilities so that meaningful tests can be carried out. Another important effort during this period has been the creation of a materials database. Computer systems administration and support have also been provided. These are described in greater detail below.

  17. Test model designs for advanced refractory ceramic materials

    NASA Technical Reports Server (NTRS)

    Tran, Huy Kim

    1993-01-01

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

  18. Review on advanced composite materials boring mechanism and tools

    NASA Astrophysics Data System (ADS)

    Shi, Runping; Wang, Chengyong

    2010-12-01

    With the rapid development of aviation and aerospace manufacturing technology, advanced composite materials represented by carbon fibre reinforced plastics (CFRP) and super hybrid composites (fibre/metal plates) are more and more widely applied. The fibres are mainly carbon fibre, boron fibre, Aramid fiber and Sic fibre. The matrixes are resin matrix, metal matrix and ceramic matrix. Advanced composite materials have higher specific strength and higher specific modulus than glass fibre reinforced resin composites of the 1st generation. They are widely used in aviation and aerospace industry due to their high specific strength, high specific modulus, excellent ductility, anticorrosion, heat-insulation, sound-insulation, shock absorption and high&low temperature resistance. They are used for radomes, inlets, airfoils(fuel tank included), flap, aileron, vertical tail, horizontal tail, air brake, skin, baseboards and tails, etc. Its hardness is up to 62~65HRC. The holes are greatly affected by the fibre laminates direction of carbon fibre reinforced composite material due to its anisotropy when drilling in unidirectional laminates. There are burrs, splits at the exit because of stress concentration. Besides there is delamination and the hole is prone to be smaller. Burrs are caused by poor sharpness of cutting edge, delamination, tearing, splitting are caused by the great stress caused by high thrust force. Poorer sharpness of cutting edge leads to lower cutting performance and higher drilling force at the same time. The present research focuses on the interrelation between rotation speed, feed, drill's geometry, drill life, cutting mode, tools material etc. and thrust force. At the same time, holes quantity and holes making difficulty of composites have also increased. It requires high performance drills which won't bring out defects and have long tool life. It has become a trend to develop super hard material tools and tools with special geometry for drilling

  19. Review on advanced composite materials boring mechanism and tools

    NASA Astrophysics Data System (ADS)

    Shi, Runping; Wang, Chengyong

    2011-05-01

    With the rapid development of aviation and aerospace manufacturing technology, advanced composite materials represented by carbon fibre reinforced plastics (CFRP) and super hybrid composites (fibre/metal plates) are more and more widely applied. The fibres are mainly carbon fibre, boron fibre, Aramid fiber and Sic fibre. The matrixes are resin matrix, metal matrix and ceramic matrix. Advanced composite materials have higher specific strength and higher specific modulus than glass fibre reinforced resin composites of the 1st generation. They are widely used in aviation and aerospace industry due to their high specific strength, high specific modulus, excellent ductility, anticorrosion, heat-insulation, sound-insulation, shock absorption and high&low temperature resistance. They are used for radomes, inlets, airfoils(fuel tank included), flap, aileron, vertical tail, horizontal tail, air brake, skin, baseboards and tails, etc. Its hardness is up to 62~65HRC. The holes are greatly affected by the fibre laminates direction of carbon fibre reinforced composite material due to its anisotropy when drilling in unidirectional laminates. There are burrs, splits at the exit because of stress concentration. Besides there is delamination and the hole is prone to be smaller. Burrs are caused by poor sharpness of cutting edge, delamination, tearing, splitting are caused by the great stress caused by high thrust force. Poorer sharpness of cutting edge leads to lower cutting performance and higher drilling force at the same time. The present research focuses on the interrelation between rotation speed, feed, drill's geometry, drill life, cutting mode, tools material etc. and thrust force. At the same time, holes quantity and holes making difficulty of composites have also increased. It requires high performance drills which won't bring out defects and have long tool life. It has become a trend to develop super hard material tools and tools with special geometry for drilling

  20. A manufacturing database of advanced materials used in spacecraft structures

    NASA Technical Reports Server (NTRS)

    Bao, Han P.

    1994-01-01

    Cost savings opportunities over the life cycle of a product are highest in the early exploratory phase when different design alternatives are evaluated not only for their performance characteristics but also their methods of fabrication which really control the ultimate manufacturing costs of the product. In the past, Design-To-Cost methodologies for spacecraft design concentrated on the sizing and weight issues more than anything else at the early so-called 'Vehicle Level' (Ref: DOD/NASA Advanced Composites Design Guide). Given the impact of manufacturing cost, the objective of this study is to identify the principal cost drivers for each materials technology and propose a quantitative approach to incorporating these cost drivers into the family of optimization tools used by the Vehicle Analysis Branch of NASA LaRC to assess various conceptual vehicle designs. The advanced materials being considered include aluminum-lithium alloys, thermoplastic graphite-polyether etherketone composites, graphite-bismaleimide composites, graphite- polyimide composites, and carbon-carbon composites. Two conventional materials are added to the study to serve as baseline materials against which the other materials are compared. These two conventional materials are aircraft aluminum alloys series 2000 and series 7000, and graphite-epoxy composites T-300/934. The following information is available in the database. For each material type, the mechanical, physical, thermal, and environmental properties are first listed. Next the principal manufacturing processes are described. Whenever possible, guidelines for optimum processing conditions for specific applications are provided. Finally, six categories of cost drivers are discussed. They include, design features affecting processing, tooling, materials, fabrication, joining/assembly, and quality assurance issues. It should be emphasized that this database is not an exhaustive database. Its primary use is to make the vehicle designer

  1. Advanced Materials Development Program: Ceramic Technology for Advanced Heat Engines program plan, 1983--1993

    SciTech Connect

    Not Available

    1990-07-01

    The purpose of the Ceramic Technology for Advanced Heat Engines (CTAHE) Project is the development of an industrial technology base capable of providing reliable and cost-effective high temperature ceramic components for application in advanced heat engines. There is a deliberate emphasis on industrial'' in the purpose statement. The project is intended to support the US ceramic and engine industries by providing the needed ceramic materials technology. The heat engine programs have goals of component development and proof-of-concept. The CTAHE Project is aimed at developing generic basic ceramic technology and does not involve specific engine designs and components. The materials research and development efforts in the CTAHE Project are focused on the needs and general requirements of the advanced gas turbine and low heat rejection diesel engines. The CTAHE Project supports the DOE Office of Transportation Systems' heat engine programs, Advanced Turbine Technology Applications (ATTAP) and Heavy Duty Transport (HDT) by providing the basic technology required for development of reliable and cost-effective ceramic components. The heat engine programs provide the iterative component design, fabrication, and test development logic. 103 refs., 18 figs., 11 tabs.

  2. (Advanced materials, robotics, and advanced computers for use in nuclear power plants)

    SciTech Connect

    White, J.D.

    1989-11-17

    The aim of the IAEA Technical Committee Workshop was to provide an opportunity to exchange information on the status of advances in technologies such as improved materials, robotics, and advanced computers already used or expected to be used in the design of nuclear power plants, and to review possible applications of advanced technologies in future reactor designs. Papers were given in these areas by Belgium, France, Mexico, Canada, Russia, India, and the United States. Notably absent from this meeting were Japan, Germany, Italy, Spain, the United Kingdom, and the Scandinavian countries -- all of whom are working in the areas of interest to this meeting. Most of the workshop discussion, however, was focused on advanced controls (including human-machine interface and software development and testing) and electronic descriptions of power plants. Verification and validation of design was also a topic of considerable discussion. The traveler was surprised at the progress made in 3-D electronic images of nuclear power plants and automatic updating of these images to reflect as-built conditions. Canadian plants and one Mexican plant have used photogrammetry to update electronic drawings automatically. The Canadians also have started attaching other electronic data bases to the electronic drawings. These data bases include parts information and maintenance work. The traveler observed that the Advanced Controls Program is better balanced and more forward looking than other nuclear controls R D activities described. The French participants made this observation in the meeting and expressed interest in collaborative work in this area.

  3. Four advances in carbon-carbon materials technology

    NASA Technical Reports Server (NTRS)

    Maahs, Howard G.; Vaughn, Wallace L.; Kowbel, Witold

    1994-01-01

    Carbon-carbon composites are a specialty class of materials having many unique properties making these composites attractive for a variety of demanding engineering applications. Chief among these properties are exceptional retention of mechanical properties at temperatures as high as 4000 F, excellent creep resistance, and low density (1.6 to 1.8 g/cu cm). Although carbon-carbon composites are currently in service in a variety of applications, much development work remains to be accomplished before these materials can be considered to be fully mature, realizing their full potential. Four recent technology advances holding particular promise for overcoming current barriers to the wide-spread commercialization of carbon-carbon composites are described. These advances are: markedly improved interlaminar strengths (more than doubled) of two dimensional composites achieved by whiskerization of the fabric reinforcing plies, simultaneously improved oxidation resistance and mechanical properties achieved by the incorporation of matrix-phase oxidation inhibitors based on carborane chemistry, improved oxidation resistance achieved by compositionally graded oxidation protective coatings, and markedly reduced processing times (hours as opposed to weeks or months) accomplished through a novel process of carbon infiltration and coatings deposition based on the use of liquid-phase precursor materials.

  4. Improve the performance of coated cemented hip stem through the advanced composite materials.

    PubMed

    Hedia, H S; Fouda, N

    2015-01-01

    Design of hip joint implant using functionally graded material (FGM) (advanced composite material) has been used before through few researches. It gives great results regarding the stress distribution along the implant and bone interfaces. However, coating of orthopaedic implants has been widely investigated through many researches. The effect of using advanced composite stem material, which mean by functionally graded stem material, in the total hip replacement coated with the most common coated materials has not been studied yet. Therefore, this study investigates the effect of utilizing these two concepts together; FGM and coating, in designing new stem material. It is concluded that the optimal FGM cemented stem is consisting from titanium at the upper stem layers graded to collagen at a lower stem layers. This optimal graded stem coated with hydroxyapatite found to reduce stress shielding by 57% compared to homogenous titanium stem coated with hydroxyapatite. However, the optimal functionally graded stem coated with collagen reduced the stress shielding by 51% compared to homogenous titanium stem coated with collagen. PMID:26407117

  5. Recent advances in 2D materials for photocatalysis

    NASA Astrophysics Data System (ADS)

    Luo, Bin; Liu, Gang; Wang, Lianzhou

    2016-03-01

    Two-dimensional (2D) materials have attracted increasing attention for photocatalytic applications because of their unique thickness dependent physical and chemical properties. This review gives a brief overview of the recent developments concerning the chemical synthesis and structural design of 2D materials at the nanoscale and their applications in photocatalytic areas. In particular, recent progress on the emerging strategies for tailoring 2D material-based photocatalysts to improve their photo-activity including elemental doping, heterostructure design and functional architecture assembly is discussed.

  6. Low work function thermionic emission materials

    SciTech Connect

    Zavadil, K.R.; King, D.B.; Ruffner, J.A.

    1999-11-01

    Thermionic energy conversion in a microminiature format shows potential as a viable, high efficiency, on-chip power source. Microminiature thermionic converters (MTC) with inter-electrode spacings on the order of microns are currently being prototyped and evaluated at Sandia. The remaining enabling technology is the development of low work function materials and processes than can be integrated into these converters. In this report, the authors demonstrate a method of incorporating thin film emitters into converters using rf sputtering. They find that the resultant films possess a minimum work function of 1.2 eV. Practical energy conversion is hindered by surface work function non-uniformity. They postulate the source of this heterogeneity to be a result of limited bulk and surface transport of barium. Several methods are proposed for maximizing transport, including increased film porosity and the use of metal terminating layers. They demonstrate a novel method for incorporating film porosity based on metal interlayer coalescence.

  7. Materials and Component Development for Advanced Turbine Systems

    SciTech Connect

    Alvin, M A; Pettit, F; Meier, G H; Yanar, M; Helminiak, M; Chyu, M; Siw, S; Slaughter, W S; Karaivanov, V; Kang, B S; Feng, C; Tannebaum, J M; Chen, R; Zhang, B; Fu, T; Richards, G A; Sidwell, T G; Straub, D; Casleton, K H; Dogan, O M

    2008-07-01

    Hydrogen-fired and oxy-fueled land-based gas turbines currently target inlet operating temperatures of ~1425-1760°C (~2600-3200°F). In view of natural gas or syngas-fired engines, advancements in both materials, as well as aerothermal cooling configurations are anticipated prior to commercial operation. This paper reviews recent technical accomplishments resulting from NETL’s collaborative research efforts with the University of Pittsburgh and West Virginia University for future land-based gas turbine applications.

  8. Design of Functional Materials based on Liquid Crystalline Droplets

    PubMed Central

    Miller, Daniel S.; Wang, Xiaoguang; Abbott, Nicholas L.

    2014-01-01

    This brief perspective focuses on recent advances in the design of functional soft materials that are based on confinement of low molecular weight liquid crystals (LCs) within micrometer-sized droplets. While the ordering of LCs within micrometer-sized domains has been explored extensively in polymer-dispersed LC materials, recent studies performed with LC domains with precisely defined size and interfacial chemistry have unmasked observations of confinement-induced ordering of LCs that do not follow previously reported theoretical predictions. These new findings, which are enabled in part by advances in the preparation of LCs encapsulated in polymeric shells, are opening up new opportunities for the design of soft responsive materials based on surface-induced ordering transitions. These materials are also providing new insights into the self-assembly of biomolecular and colloidal species at defects formed by LCs confined to micrometer-sized domains. The studies presented in this perspective serve additionally to highlight gaps in knowledge regarding the ordering of LCs in confined systems. PMID:24882944

  9. Modeling the Behaviour of an Advanced Material Based Smart Landing Gear System for Aerospace Vehicles

    SciTech Connect

    Varughese, Byji; Dayananda, G. N.; Rao, M. Subba

    2008-07-29

    The last two decades have seen a substantial rise in the use of advanced materials such as polymer composites for aerospace structural applications. In more recent years there has been a concerted effort to integrate materials, which mimic biological functions (referred to as smart materials) with polymeric composites. Prominent among smart materials are shape memory alloys, which possess both actuating and sensory functions that can be realized simultaneously. The proper characterization and modeling of advanced and smart materials holds the key to the design and development of efficient smart devices/systems. This paper focuses on the material characterization; modeling and validation of the model in relation to the development of a Shape Memory Alloy (SMA) based smart landing gear (with high energy dissipation features) for a semi rigid radio controlled airship (RC-blimp). The Super Elastic (SE) SMA element is configured in such a way that it is forced into a tensile mode of high elastic deformation. The smart landing gear comprises of a landing beam, an arch and a super elastic Nickel-Titanium (Ni-Ti) SMA element. The landing gear is primarily made of polymer carbon composites, which possess high specific stiffness and high specific strength compared to conventional materials, and are therefore ideally suited for the design and development of an efficient skid landing gear system with good energy dissipation characteristics. The development of the smart landing gear in relation to a conventional metal landing gear design is also dealt with.

  10. Modeling the Behaviour of an Advanced Material Based Smart Landing Gear System for Aerospace Vehicles

    NASA Astrophysics Data System (ADS)

    Varughese, Byji; Dayananda, G. N.; Rao, M. Subba

    2008-07-01

    The last two decades have seen a substantial rise in the use of advanced materials such as polymer composites for aerospace structural applications. In more recent years there has been a concerted effort to integrate materials, which mimic biological functions (referred to as smart materials) with polymeric composites. Prominent among smart materials are shape memory alloys, which possess both actuating and sensory functions that can be realized simultaneously. The proper characterization and modeling of advanced and smart materials holds the key to the design and development of efficient smart devices/systems. This paper focuses on the material characterization; modeling and validation of the model in relation to the development of a Shape Memory Alloy (SMA) based smart landing gear (with high energy dissipation features) for a semi rigid radio controlled airship (RC-blimp). The Super Elastic (SE) SMA element is configured in such a way that it is forced into a tensile mode of high elastic deformation. The smart landing gear comprises of a landing beam, an arch and a super elastic Nickel-Titanium (Ni-Ti) SMA element. The landing gear is primarily made of polymer carbon composites, which possess high specific stiffness and high specific strength compared to conventional materials, and are therefore ideally suited for the design and development of an efficient skid landing gear system with good energy dissipation characteristics. The development of the smart landing gear in relation to a conventional metal landing gear design is also dealt with.

  11. Advanced Test Reactor National Scientific User Facility: Addressing advanced nuclear materials research

    SciTech Connect

    John Jackson; Todd Allen; Frances Marshall; Jim Cole

    2013-03-01

    The Advanced Test Reactor National Scientific User Facility (ATR NSUF), based at the Idaho National Laboratory in the United States, is supporting Department of Energy and industry research efforts to ensure the properties of materials in light water reactors are well understood. The ATR NSUF is providing this support through three main efforts: establishing unique infrastructure necessary to conduct research on highly radioactive materials, conducting research in conjunction with industry partners on life extension relevant topics, and providing training courses to encourage more U.S. researchers to understand and address LWR materials issues. In 2010 and 2011, several advanced instruments with capability focused on resolving nuclear material performance issues through analysis on the micro (10-6 m) to atomic (10-10 m) scales were installed primarily at the Center for Advanced Energy Studies (CAES) in Idaho Falls, Idaho. These instruments included a local electrode atom probe (LEAP), a field-emission gun scanning transmission electron microscope (FEG-STEM), a focused ion beam (FIB) system, a Raman spectrometer, and an nanoindentor/atomic force microscope. Ongoing capability enhancements intended to support industry efforts include completion of two shielded, irradiation assisted stress corrosion cracking (IASCC) test loops, the first of which will come online in early calendar year 2013, a pressurized and controlled chemistry water loop for the ATR center flux trap, and a dedicated facility intended to house post irradiation examination equipment. In addition to capability enhancements at the main site in Idaho, the ATR NSUF also welcomed two new partner facilities in 2011 and two new partner facilities in 2012; the Oak Ridge National Laboratory, High Flux Isotope Reactor (HFIR) and associated hot cells and the University California Berkeley capabilities in irradiated materials analysis were added in 2011. In 2012, Purdue University’s Interaction of Materials

  12. A Novel Microcharacterization Technique in the Measurement of Strain and Orientation Gradient in Advanced Materials

    NASA Technical Reports Server (NTRS)

    Garmestai, H.; Harris, K.; Lourenco, L.

    1997-01-01

    Representation of morphology and evolution of the microstructure during processing and their relation to properties requires proper experimental techniques. Residual strains, lattice distortion, and texture (micro-texture) at the interface and the matrix of a layered structure or a functionally gradient material and their variation are among parameters important in materials characterization but hard to measure with present experimental techniques. Current techniques available to measure changes in interred material parameters (residual stress, micro-texture, microplasticity) produce results which are either qualitative or unreliable. This problem becomes even more complicated in the case of a temperature variation. These parameters affect many of the mechanical properties of advanced materials including stress-strain relation, ductility, creep, and fatigue. A review of some novel experimental techniques using recent advances in electron microscopy is presented here to measure internal stress, (micro)texture, interracial strength and (sub)grain formation and realignment. Two of these techniques are combined in the chamber of an Environmental Scanning Electron Microscope to measure strain and orientation gradients in advanced materials. These techniques which include Backscattered Kikuchi Diffractometry (BKD) and Microscopic Strain Field Analysis are used to characterize metallic and intermetallic matrix composites and superplastic materials. These techniques are compared with the more conventional x-ray diffraction and indentation techniques.

  13. Cost/benefit studies of advanced materials technologies for future aircraft turbine engines: Materials for advanced turbine engines

    NASA Technical Reports Server (NTRS)

    Stearns, M.; Wilbers, L.

    1982-01-01

    Cost benefit studies were conducted on six advanced materials and processes technologies applicable to commercial engines planned for production in the 1985 to 1990 time frame. These technologies consisted of thermal barrier coatings for combustor and high pressure turbine airfoils, directionally solidified eutectic high pressure turbine blades, (both cast and fabricated), and mixers, tail cones, and piping made of titanium-aluminum alloys. A fabricated titanium fan blisk, an advanced turbine disk alloy with improved low cycle fatigue life, and a long-life high pressure turbine blade abrasive tip and ceramic shroud system were also analyzed. Technologies showing considerable promise as to benefits, low development costs, and high probability of success were thermal barrier coating, directionally solidified eutectic turbine blades, and abrasive-tip blades/ceramic-shroud turbine systems.

  14. Advanced Hot Section Materials and Coatings Test Rig

    SciTech Connect

    Dan Davis

    2006-09-30

    Phase I of the Hyperbaric Advanced Hot Section Materials & Coating Test Rig Program has been successfully completed. Florida Turbine Technologies has designed and planned the implementation of a laboratory rig capable of simulating the hot gas path conditions of coal gas fired industrial gas turbine engines. Potential uses of this rig include investigations into environmental attack of turbine materials and coatings exposed to syngas, erosion, and thermal-mechanical fatigue. The principle activities during Phase 1 of this project included providing several conceptual designs for the test section, evaluating various syngas-fueled rig combustor concepts, comparing the various test section concepts and then selecting a configuration for detail design. Conceptual definition and requirements of auxiliary systems and facilities were also prepared. Implementation planning also progressed, with schedules prepared and future project milestones defined. The results of these tasks continue to show rig feasibility, both technically and economically.

  15. Fracture behaviour of functionally graded materials

    NASA Astrophysics Data System (ADS)

    Marur, Prabhakar R.

    Functionally graded materials (FGMs) are special composites consisting of two constituent phases whose composition change continuously along one direction. The gradual transition in material properties alleviates thermal mismatch problems experienced by cladded and coated components. The microstructure of FGM is usually heterogenous and the dominant failure mode of FGM is the crack initiation and propagation from the inclusions. Hence, the knowledge of crack growth and propagation is important in designing components involving FGM. The interface crack problem is studied by examining the asymptotic behavior of stress and displacement fields around the crack in FGM, and by comparing the results with known solutions for bimaterial systems. The, focus is on characterizing the influence of material nonhomogeneity on the fracture parameters, and determining the fracture strength of FGM under quasi-static and dynamic loading. The numerical and experimental techniques developed in this study are unified for both bimaterial and FGM, permitting direct comparison of fracture parameters and test results obtained for different material types. A crack opening displacement (COD) extrapolation technique is developed for the numerical computation of the fracture parameters from finite element analysis, and a new strain gage technique is devised for complex SIF measurement in both bimaterial and FGM. A simple and highly repeatable FGM manufacturing process has been established, and the continuous variation of material properties is evaluated using a novel technique involving ultrasonic wave velocity and local contact stiffness measurements. The nature of singular field around the crack in FGM is studied by varying material gradient, the position of the crack in the graded region and the crack length. The various fracture parameters are compared with that computed for homogenous and bimaterial counterparts. The numerical results show that the crack in FGM, regardless of the position

  16. Magnetic spectroscopy and microscopy of functional materials

    SciTech Connect

    Jenkins, Catherine Ann

    2011-05-01

    Heusler intermetallics Mn2Y Ga and X2MnGa (X; Y =Fe, Co, Ni) undergo tetragonal magnetostructural transitions that can result in half metallicity, magnetic shape memory, or the magnetocaloric effect. Understanding the magnetism and magnetic behavior in functional materials is often the most direct route to being able to optimize current materials for todays applications and to design novel ones for tomorrow. Synchrotron soft x-ray magnetic spectromicroscopy techniques are well suited to explore the the competing effects from the magnetization and the lattice parameters in these materials as they provide detailed element-, valence-, and site-specifc information on the coupling of crystallographic ordering and electronic structure as well as external parameters like temperature and pressure on the bonding and exchange. Fundamental work preparing the model systems of spintronic, multiferroic, and energy-related compositions is presented for context. The methodology of synchrotron spectroscopy is presented and applied to not only magnetic characterization but also of developing a systematic screening method for future examples of materials exhibiting any of the above effects. The chapter progression is as follows: an introduction to the concepts and materials under consideration (Chapter 1); an overview of sample preparation techniques and results, and the kinds of characterization methods employed (Chapter 2); spectro- and microscopic explorations of X2MnGa/Ge (Chapter 3); spectroscopic investigations of the composition series Mn2Y Ga to the logical Mn3Ga endpoint (Chapter 4); and a summary and overview of upcoming work (Chapter 5). Appendices include the results of a Think Tank for the Graduate School of Excellence MAINZ (Appendix A) and details of an imaging project now in progress on magnetic reversal and domain wall observation in the classical Heusler material Co2FeSi (Appendix B).

  17. Evaluation and Validation of Organic Materials for Advanced Stirling Convertors (ASCs): Overview

    NASA Technical Reports Server (NTRS)

    Shin, Euy-Sik Eugene

    2015-01-01

    Various organic materials are used as essential parts in Stirling Convertors for their unique properties and functionalities such as bonding, potting, sealing, thread locking, insulation, and lubrication. More efficient Advanced Stirling Convertors (ASC) are being developed for future space applications especially with a long mission cycle, sometimes up to 17 years, such as deep space exploration or lunar surface power or Mars rovers, and others. Thus, performance, durability, and reliability of those organics should be critically evaluated in every possible material-process-fabrication-service environment relations based on their mission specifications. In general, thermal stability, radiation hardness, outgassing, and material compatibility of the selected organics have been systematically evaluated while their process and fabrication conditions and procedures were being optimized. Service environment-simulated long term aging tests up to 4 years were performed as a function of temperature for durability assessment of the most critical organic material systems.

  18. Interfacial properties and design of functional energy materials.

    PubMed

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

    2014-11-18

    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

  19. NASA's Advanced Space Transportation Program: A Materials Overview

    NASA Technical Reports Server (NTRS)

    Clinton, R. G., Jr.

    1999-01-01

    The realization of low-cost assess to space is one of NASA's three principal goals or "pillars" under the Office of Aero-Space Technology. In accordance with the goals of this pillar, NASA's primary space transportation technology role is to develop and demonstrate next-generation technologies to enable the commercial launch industry to develop full-scale, low cost, highly reliable space launchers. The approach involves both ground-based technology demonstrations and flight demonstrators, including the X-33, X-34, Bantam, Reusable Launch Vehicle (RLV), and future experimental vehicles. Next generation space transportation vehicles and propulsion systems will require the development and implementation of advanced materials and processes. This presentation will provide an overview of advanced materials efforts which are focused on the needs of next generation space transportation systems. Applications described will include ceramic matrix composite (CMC) integrally bladed turbine disk (blisk); actively cooled CMC nozzle ramp for the aerospike engine; ablative thrust chamber/nozzle; and metal matrix composite turbomachinery housings.

  20. On fracture phenomena in advanced fiber composite materials.

    NASA Technical Reports Server (NTRS)

    Konish, H. J., Jr.; Swedlow, J. L.; Cruse, T. A.

    1972-01-01

    The extension of linear elastic fracture mechanics (LEFM) from metallic alloys to advanced fiber composite laminates is considered. LEFM is shown to be valid for both isotropic and anisotropic homogeneous continua; the applicability of LEFM to advanced fiber composites is thus dependent on the validity of a homogeneous model of such materials. An experimental program to determine the validity of such a model for graphite/epoxy laminates is reviewed. Such laminates are found to have an apparent fracture toughness, from which it is inferred that a homogeneous material model is valid for the particular specimen geometry and composite laminates considered. Strain energy release rates are calculated from the experimentally determined fracture toughness of the various laminates. These strain energy release rates are found to lie in one of two groups, depending upon whether crack extension required fiber failure or matrix failure. The latter case is further investigated. It is concluded that matrix failure is governed by the tensile stress normal to the crack path.

  1. Advanced nanoimprint patterning for functional electronics and biochemical sensing

    NASA Astrophysics Data System (ADS)

    Wang, Chao

    Nano-fabrication has been widely used for a variety of disciplines, including electronics, material science, nano-optics, and nano-biotechnology. This dissertation focuses on nanoimprint lithography (NIL) based novel nano-patterning techniques for fabricating functional structures, and discusses their applications in advanced electronics and high-sensitivity molecular sensing. In this dissertation, examples of using nano-fabricated structures for promising electronic applications are presented. For instance, 10 nm and 18 nm features are NIL-fabricated for Si/SiGe heterojunction tunneling transistors and graphene nano-ribbon transistors, using shadow evaporation and line-width shrinking techniques, respectively. An ultrafast laser melting based method is applied on flexible plastic substrates to correct defects of nano-features. Nano-texturing of sapphire substrate is developed to improve the light extraction of GaN light emitting diodes (LEDs) by 70 %. A novel multi-layer nano-patterned Si-mediated catalyst is discovered to grow straight and uniform Si nanowires with optimized properties in size, location, and crystallization on amorphous SiO2 substrate. Nano-structures are also functionalized into highly sensitive bio-chemical sensors. Plasmonic nano-bar antenna arrays are demonstrated to effectively sense infrared molecules >10 times better than conventional plasmonic sensors. As small as 20 nm wide nano-channel fluidic devices are developed to linearize and detect DNA molecules for potential DNA sequencing. An integrated fluidic system is built to incorporate plasmonic nano-structures for 30X-enhanced fluorescence detection of large DNA molecules.

  2. Advanced materials for improved PEMFC performance and life

    NASA Astrophysics Data System (ADS)

    Curtin, Dennis E.; Lousenberg, Robert D.; Henry, Timothy J.; Tangeman, Paul C.; Tisack, Monica E.

    Physical and functional attributes are reviewed for recently developed Nafion ® products that satisfy emerging fuel cell requirements—including stronger, more durable membranes, and polymer dispersions of higher quality and consistency for catalyst inks and film formation. Size exclusion chromatography (SEC) analysis has confirmed that dispersion viscosity is related to an "apparent" molar mass, resulting from a molecular aggregate structure. Membranes produced with solution-casting and advanced extrusion technologies exhibit improved water management and mechanical durability features, respectively. Additionally, DuPont has shown that experimentally modified Nafion ® polymer exhibits 56% reduction in fluoride ion generation, which is considered a measure of membrane lifetime.

  3. Advanced Industrial Materials (AIM) Program annual progress report, FY 1997

    SciTech Connect

    1998-05-01

    The Advanced Industrial Materials (AIM) Program is a part of the Office of Industrial Technologies (OIT), Energy Efficiency and Renewable Energy, US Department of Energy (DOE). The mission of AIM is to support development and commercialization of new or improved materials to improve energy efficiency, productivity, product quality, and reduced waste in the major process industries. OIT has embarked on a fundamentally new way of working with industries--the Industries of the Future (IOF) strategy--concentrating on the major process industries that consume about 90% of the energy and generate about 90% of the waste in the industrial sector. These are the aluminum, chemical, forest products, glass, metalcasting, and steel industries. OIT has encouraged and assisted these industries in developing visions of what they will be like 20 or 30 years into the future, defining the drivers, technology needs, and barriers to realization of their visions. These visions provide a framework for development of technology roadmaps and implementation plans, some of which have been completed. The AIM Program supports IOF by conducting research and development on materials to solve problems identified in the roadmaps. This is done by National Laboratory/industry/university teams with the facilities and expertise needed to develop new and improved materials. Each project in the AIM Program has active industrial participation and support.

  4. Combustion Synthesis of Advanced Porous Materials in Microgravity Environment

    NASA Technical Reports Server (NTRS)

    Zhang, X.; Moore, J. J.; Schowengerdt, F. D.; Johnson, D. P.

    1999-01-01

    Combustion synthesis, otherwise known as self-propagating high temperature synthesis (SHS), can be used to produce engineered advanced porous material implants which offer the possibility for bone ingrowth as well as a permanent structure framework for the long-term replacement of bone defects. The primary advantage of SHS is based on its rapid kinetics and favorable energetics. The structure and properties of materials produced by SHS are strongly dependent on the combustion reaction conditions. Combustion reaction conditions such as reaction stoichiometry, particle size, green density, the presence and use of diluents or inert reactants, and pre-heating of the reactants, will affect the exothermicity of the reaction. A number of conditions must be satisfied in order to obtain high porosity materials: an optimal amount of liquid, gas and solid phases must be present in the combustion front. Therefore, a balance among these phases at the combustion front must be created by the SHS reaction to successfully engineer a bone replacement material system. Microgravity testing has extended the ability to form porous products. The convective heat transfer mechanisms which operate in normal gravity, 1 g, constrain the combustion synthesis reactions. Gravity also acts to limit the porosity which may be formed as the force of gravity serves to restrict the gas expansion and the liquid movement during reaction. Infiltration of the porous product with other phases can modify both the extent of porosity and the mechanical properties.

  5. High Speed SPM of Functional Materials

    SciTech Connect

    Huey, Bryan D.

    2015-08-14

    The development and optimization of applications comprising functional materials necessitates a thorough understanding of their static and dynamic properties and performance at the nanoscale. Leveraging High Speed SPM and concepts enabled by it, efficient measurements and maps with nanoscale and nanosecond temporal resolution are uniquely feasible. This includes recent enhancements for topographic, conductivity, ferroelectric, and piezoelectric properties as originally proposed, as well as newly developed methods or improvements to AFM-based mechanical, friction, thermal, and photoconductivity measurements. The results of this work reveal fundamental mechanisms of operation, and suggest new approaches for improving the ultimate speed and/or efficiency, of data storage systems, magnetic-electric sensors, and solar cells.

  6. Gen IV Materials Handbook Functionalities and Operation

    SciTech Connect

    Ren, Weiju

    2009-12-01

    This document is prepared for navigation and operation of the Gen IV Materials Handbook, with architecture description and new user access initiation instructions. Development rationale and history of the Handbook is summarized. The major development aspects, architecture, and design principles of the Handbook are briefly introduced to provide an overview of its past evolution and future prospects. Detailed instructions are given with examples for navigating the constructed Handbook components and using the main functionalities. Procedures are provided in a step-by-step fashion for Data Upload Managers to upload reports and data files, as well as for new users to initiate Handbook access.

  7. Validation of an Advanced Material Model for Simulating the Impact and Shock Response of Composite Materials

    NASA Astrophysics Data System (ADS)

    Clegg, Richard A.; Hayhurst, Colin J.; Nahme, Hartwig

    2002-07-01

    Composite materials are now commonly used as ballistic and hypervelocity protection materials and the demand for simulation of impact on these materials is increasing. A new material model specifically designed for the shock response of anisotropic materials has been developed and implemented in the hydrocode AUTODYN. The model allows for the representation of non-linear shock effects in combination with anisotropic material stiffness and damage. The coupling of the equation of state and anisotropic response is based on the methodology proposed by Anderson et al. [2]. An overview of the coupled formulation is described in order to point out the important assumptions, key innovations and basic theoretical framework. The coupled model was originally developed by Century Dynamics and Fhg-EMI for assessing the hypervelocity impact response of composite satellite protection systems [1]. It was also identified that the developed model should also offer new possibilities and capabilities for modelling modern advanced armour materials. Validation of the advanced composite model is firstly shown via simulations of uniaxial strain flyer plate experiments on aramid and polyethylene fibre composite systems. Finally, practical application of the model as implemented in AUTODYN is demonstrated through the simulation of ballistic and hypervelocity impact events. Comparison with experiment is given where possible.

  8. Engineering Cell Instructive Materials To Control Cell Fate and Functions through Material Cues and Surface Patterning.

    PubMed

    Ventre, Maurizio; Netti, Paolo A

    2016-06-22

    Mastering the interaction between cells and extracellular environment is a fundamental prerequisite in order to engineer functional biomaterial interfaces able to instruct cells with specific commands. Such advanced biomaterials might find relevant application in prosthesis design, tissue engineering, diagnostics and stem cell biology. Because of the highly complex, dynamic, and multifaceted context, a thorough understanding of the cell-material crosstalk has not been achieved yet; however, a variety of material features including biological cues, topography, and mechanical properties have been proved to impact the strength and the nature of the cell-material interaction, eventually affecting cell fate and functions. Although the nature of these three signals may appear very different, they are equated by their participation in the same material-cytoskeleton crosstalk pathway as they regulate cell adhesion events. In this work we present recent and relevant findings on the material-induced cell responses, with a particular emphasis on how the presentation of biochemical/biophysical signals modulates cell behavior. Finally, we summarize and discuss the literature data to draw out unifying elements concerning cell recognition of and reaction to signals displayed by material surfaces. PMID:26693600

  9. Surface Functionalization of Graphene-based Materials

    NASA Astrophysics Data System (ADS)

    Mathkar, Akshay

    Graphene-based materials have generated tremendous interest in the past decade. Manipulating their characteristics using wet-chemistry methods holds distinctive value, as it provides a means towards scaling up, while not being limited by yield. The majority of this thesis focuses on the surface functionalization of graphene oxide (GO), which has drawn tremendous attention as a tunable precursor due to its readily chemically manipulable surface and richly functionalized basal plane. Firstly, a room-temperature based method is presented to reduce GO stepwise, with each organic moiety being removed sequentially. Characterization confirms the carbonyl group to be reduced first, while the tertiary alcohol is reduced last, as the optical gap decrease from 3.5 eV down to 1 eV. This provides greater control over GO, which is an inhomogeneous system, and is the first study to elucidate the order of removal of each functional group. In addition to organically manipulating GO, this thesis also reports a chemical methodology to inorganically functionalize GO and tune its wetting characteristics. A chemical method to covalently attach fluorine atoms in the form of tertiary alkyl fluorides is reported, and confirmed by MAS 13C NMR, as two forms of fluorinated graphene oxide (FGO) with varying C/F and C/O ratios are synthesized. Introducing C-F bonds decreases the overall surface free energy, which drastically reduces GO's wetting behavior, especially in its highly fluorinated form. Ease of solution processing leads to development of sprayable inks that are deposited on a range of porous and nonporous surfaces to impart amphiphobicity. This is the first report that tunes the wetting characteristics of GO. Lastly as a part of a collaboration with ConocoPhillips, another class of carbon nanomaterials - carbon nanotubes (CNTs), have been inorganically functionalized to repel 30 wt% MEA, a critical solvent in CO 2 recovery. In addition to improving the solution processability of CNTs

  10. PREFACE Conference on Advanced Materials and Nanotechnology (CAMAN 2009)

    NASA Astrophysics Data System (ADS)

    Ali, Aidy

    2011-02-01

    This special issue of IOP Conference Series: Materials science and Engineering contains papers contributed to the Conference on Advanced Materials and Nanotechnology (CAMAN 2009) held on 3-5 November 2009 in Putra World Trade Centre (PWTC), Kuala Lumpur, Malaysia. The objective of the congress is to provide a platform for professionals, academicians and researchers to exchange views, findings, ideas and experiences on advanced science and technology. After careful refereeing of all manuscripts, 50 papers were selected for publications in this issue. The policy of editing was the content of the material and its rapid dissemination was more important than its form. In 2009, the conference received close to 120 papers from leading researchers and participants from countries such as Iran, India, Switzerland, Myanmar, Nigeria, Canada, Yemen and Malaysia. We strongly hope the new ideas and results presented will stimulate and enhance the progress of research on the above conference theme. We are grateful to all the authors for their papers and presentations in this conference. They are also the ones who help make this conference possible through their hard work in the preparation of the manuscripts. We would also like to offer our sincere thanks to all the invited speakers who came to share their knowledge with us. We would also like to acknowledge the untiring efforts of the reviewers, research assistants and students in meeting deadlines and for their patience and perseverance. We wish to thank all the authors who contributed papers to the conference and all reviewers for their efforts to review the papers as well as the sponsors. We would also like to thank the members of the CAMAN 2009 Organising Committee and the International Advisory Committee for their efforts in making the conference a success. Thank you very much indeed. Guest Editor Aidy Ali

  11. Advances in dental veneers: materials, applications, and techniques

    PubMed Central

    Pini, Núbia Pavesi; Aguiar, Flávio Henrique Baggio; Lima, Débora Alves Nunes Leite; Lovadino, José Roberto; Terada, Raquel Sano Suga; Pascotto, Renata Corrêa

    2012-01-01

    Laminate veneers are a conservative treatment of unaesthetic anterior teeth. The continued development of dental ceramics offers clinicians many options for creating highly aesthetic and functional porcelain veneers. This evolution of materials, ceramics, and adhesive systems permits improvement of the aesthetic of the smile and the self-esteem of the patient. Clinicians should understand the latest ceramic materials in order to be able to recommend them and their applications and techniques, and to ensure the success of the clinical case. The current literature was reviewed to search for the most important parameters determining the long-term success, correct application, and clinical limitations of porcelain veneers. PMID:23674920

  12. Quality Assurance Protocol for AFCI Advanced Structural Materials Testing

    SciTech Connect

    Busby, Jeremy T

    2009-05-01

    The objective of this letter is to inform you of recent progress on the development of advanced structural materials in support of advanced fast reactors and AFCI. As you know, the alloy development effort has been initiated in recent months with the procurement of adequate quantities of the NF616 and HT-UPS alloys. As the test alloys become available in the coming days, mechanical testing, evaluation of optimizing treatments, and screening of environmental effects will be possible at a larger scale. It is therefore important to establish proper quality assurance protocols for this testing effort in a timely manner to ensure high technical quality throughout testing. A properly implemented quality assurance effort will also enable preliminary data taken in this effort to be qualified as NQA-1 during any subsequent licensing discussions for an advanced design or actual prototype. The objective of this report is to describe the quality assurance protocols that will be used for this effort. An essential first step in evaluating quality protocols is assessing the end use of the data. Currently, the advanced structural materials effort is part of a long-range, basic research and development effort and not, as yet, involved in licensing discussions for a specific reactor design. After consultation with Mark Vance (an ORNL QA expert) and based on the recently-issued AFCI QA requirements, the application of NQA-1 quality requirements will follow the guidance provided in Part IV, Subpart 4.2 of the NQA-1 standard (Guidance on Graded Application of QA for Nuclear-Related Research and Development). This guidance mandates the application of sound scientific methodology and a robust peer review process in all phases, allowing for the data to be qualified for use even if the programmatic mission changes to include licensing discussions of a specific design or prototype. ORNL has previously implemented a QA program dedicated to GNEP activities and based on an appropriately graded

  13. Low work function material development for the microminiature thermionic converter.

    SciTech Connect

    Zavadil, Kevin Robert; Battaile, Corbett Chandler; Marshall, Albert Christian; King, Donald Bryan; Jennison, Dwight Richard

    2004-03-01

    Thermionic energy conversion in a miniature format shows potential as a viable, high efficiency, micro to macro-scale power source. A microminiature thermionic converter (MTC) with inter-electrode spacings on the order of microns has been prototyped and evaluated at Sandia. The remaining enabling technology is the development of low work function materials and processes that can be integrated into these converters to increase power production at modest temperatures (800 - 1300 K). The electrode materials are not well understood and the electrode thermionic properties are highly sensitive to manufacturing processes. Advanced theoretical, modeling, and fabrication capabilities are required to achieve optimum performance for MTC diodes. This report describes the modeling and fabrication efforts performed to develop micro dispenser cathodes for use in the MTC.

  14. Fabrication of functional materials in microfluidics

    NASA Astrophysics Data System (ADS)

    Shum, Ho Cheung

    In this thesis, we present a study on how droplets prepared in microfluidics can be used for fabrication of functional materials. We utilize the high degree of fluidic control enabled by miniaturizing the channels to achieve monodisperse single and multiple emulsion with high encapsulation efficiency. By engineering the interfaces of such emulsions and/or applying appropriate reactions, novel functional materials have been fabricated for encapsulation and release applications and for carrying out reactions in confined environments. Glass capillary microfluidics is used in the majority of the thesis. Glass offers excellent solvent resistance to most organic solvents needed for fabricating the desired materials. In Chapter 1, we describe a double-emulsion-templated approach to form polymer vesicles, also known as polymersomes. By dissolving amphiphilic block copolymers in a volatile solvent, which forms the shell layer of double emulsions, polymersomes are formed after evaporation of the volatile solvent. In Chapter 2, we apply the same approach to fabricate phospholipid vesicles. In Chapter 3, we investigate the physics of membrane formation at interfaces laden with amphiphilic diblock copolymers. In Chapter 4, we fabricate polymersomes with multiple compaitalents by using controlled double emulsion drops with multiple inner droplets as templates. In Chapter 5, we describe a non-microfluidic approach for fabricating similar polymersomes with large number of compartments. In Chapter 6, we show that the double-emulsion templated approach for forming polymersomes can be applied to two-dimensional stamped devices, which can be easily scaled up for production of large amount of polymersomes. Apart from polymersomes, controlled emulsions can also be used for generating other functional materials. In Chapter 7, we use double emulsion drops as microreactors for fabricating particles of hydroxyapatite. In Chapter 8, we generate solid capsules by emulsifying a molten phase as

  15. The Synthesis of Functional Mesoporous Materials

    SciTech Connect

    Fryxell, Glen E.

    2006-11-01

    The ability to decorate a silica surface with specific ligand fields and/or metal complexes creates powerful new capabilities for catalysis, chemical separations and sensor development. Integrating this with the ability to control the spacing of these complexes across the surface, as well as the symmetry and size of the pore structure, allows the synthetic chemist to hierarchically tailor these structured nanomaterials to specific needs. The next step up the “scale ladder” is provided by the ability to coat these mesoporous materials onto complex shapes, allowing for the intimate integration of these tailored materials into device interfaces. The ability to tailor the pore structure of these mesoporous supports is derived from the surfactant templated synthesis of mesoporous materials, an area which has seen an explosion of activity over the last decade.[1,2] The ability to decorate the surface with the desired functionality requires chemical modification of the oxide interface, most commonly achieved using organosilane self-assembly.[3-6] This manuscript describes recent results from the confluence of these two research areas, with a focus on synthetic manipulation of the morphology and chemistry of the interface, with the ultimate goal of binding metal centers in a chemically useful manner.

  16. Plasma Functionalized Nanocarbon Materials and Their Applications

    NASA Astrophysics Data System (ADS)

    Li, Yongfeng

    2015-09-01

    The plasma treatment method is important for modifying carbon nanomaterials since it has the advantage of being nonpolluting. It has the possibility of scaling up to produce large quantities necessary for commercial use. The liquid-related plasma is especially advantageous in avoiding use of toxic stabilizers and reducing agents during the nanoparticle formation process. In this work, both gas phase and liquid phase plasmas are used to modify nanocarbon materials including graphene and carbon nanotubes. The synthesis of metal nanoparticles functionalized nanocarbon materials including carbon nanotubes and graphene has been realized by an environmentally-friendly gas-liquid interfacial method. Furthermore, the new catalysts based on hybrid of nanocarbon materials and metal nanoparticles have been proved to be stable and high catalytic performance in organic molecule transformation reactions. In addition, the modification of few-layer graphene grown by chemical vapour deposition via the nitrogen plasma ion irradiation has been performed, and the modified graphene sheets as counter electrodes in bifacial dye-sensitized solar cells exhibit high performance.

  17. Advanced Materials for High Temperature, High Performance, Wide Bandgap Power Modules

    NASA Astrophysics Data System (ADS)

    O'Neal, Chad B.; McGee, Brad; McPherson, Brice; Stabach, Jennifer; Lollar, Richard; Liederbach, Ross; Passmore, Brandon

    2016-01-01

    Advanced packaging materials must be utilized to take full advantage of the benefits of the superior electrical and thermal properties of wide bandgap power devices in the development of next generation power electronics systems. In this manuscript, the use of advanced materials for key packaging processes and components in multi-chip power modules will be discussed. For example, to date, there has been significant development in silver sintering paste as a high temperature die attach material replacement for conventional solder-based attach due to the improved thermal and mechanical characteristics as well as lower processing temperatures. In order to evaluate the bond quality and performance of this material, shear strength, thermal characteristics, and void quality for a number of silver sintering paste materials were analyzed as a die attach alternative to solder. In addition, as high voltage wide bandgap devices shift from engineering samples to commercial components, passivation materials become key in preventing premature breakdown in power modules. High temperature, high dielectric strength potting materials were investigated to be used to encapsulate and passivate components internal to a power module. The breakdown voltage up to 30 kV and corresponding leakage current for these materials as a function of temperature is also presented. Lastly, high temperature plastic housing materials are important for not only discrete devices but also for power modules. As the operational temperature of the device and/or ambient temperature increases, the mechanical strength and dielectric properties are dramatically reduced. Therefore, the electrical characteristics such as breakdown voltage and leakage current as a function of temperature for housing materials are presented.

  18. An evaluation of potential material coolant compatibility for applications in advanced fusion reactors

    NASA Astrophysics Data System (ADS)

    Kondo, T.; Watanabe, Y.; Yi, Y. S.; Hishinuma, A.

    1998-10-01

    In assessing possible potential issues for fusion applications, the compatibility of several metallic structural materials was examined using high temperature/pressure steam as test environment. High corrosion resistance associated with protective oxide film formation was regarded as essential for the function of protecting from tritium permeation and corrosion damage. A Ti-Al-based intermetallic compound with V addition, recently developed, showed excellent performance. A low-activation ferritic/martensitic steel, F82-H, was comparable with the current advanced materials for modern supercritical fossil boilers, while some potential vanadium alloys, although not intended for use in steam, were found less compatible.

  19. Factors affecting coercivity in rare-earth based advanced permanent magnet materials

    SciTech Connect

    Lewis, L.H.; Sellers, C.H.; Panchanathan, V.

    1997-02-01

    The relationships that link microstructural properties of advanced permanent magnet materials with magnetic properties such as the coercivity are often difficult to quantify, especially in materials with nano-scale structures. Recent work on RE{sub 2}Fe{sub 14}B-based powders fabricated with rapid-solidification techniques such as inert gas atomization (IGA) and melt-spinning provide insight into the nanostructural features which affect the acquisition and stability of coercivity. In all cases the coercivity is found to be a function of both the scale of the constituent microstructure and of the presence and distribution of minor phases.

  20. Damping capacity measurements for characterization of degradation in advanced materials

    SciTech Connect

    Mantena, R.; Gibson, R.F.; Place, T.A.

    1986-01-01

    This paper describes the application of damping capacity measurements for characterization of degradation in advanced materials. A recently developed impulse-frequency response technique was used to obtain damping capacity measurements on crossplied E-glass/epoxy laminates which had been subjected to four-point bending and cantilever bending to produce matrix cracking in the transverse plies. The size and location of the damage zone were correlated with changes in damping. With the expected introduction of Rapidly Solidified Alloys (RSA) as effective alternatives to conventional materials, the applicability of damping capacity measurements as a nondestructive means of evaluating degradation in these materials was also studied. A conventional A710 structural steel having three different microstructures was used for developing the methodology to be used later on RSA specimens. It is shown that damping is more sensitive to matrix cracking than stiffness is in E-glass/epoxy composite specimens. In the case of A710 steel, the damping changes at low strain, though significant, do not correlate with the mechanical property data. Damping data at high strains does correlate with the mechanical property data, however.

  1. Nanocrystalline materials: recent advances in crystallographic characterization techniques

    PubMed Central

    Ringe, Emilie

    2014-01-01

    Most properties of nanocrystalline materials are shape-dependent, providing their exquisite tunability in optical, mechanical, electronic and catalytic properties. An example of the former is localized surface plasmon resonance (LSPR), the coherent oscillation of conduction electrons in metals that can be excited by the electric field of light; this resonance frequency is highly dependent on both the size and shape of a nanocrystal. An example of the latter is the marked difference in catalytic activity observed for different Pd nanoparticles. Such examples highlight the importance of particle shape in nanocrystalline materials and their practical applications. However, one may ask ‘how are nanoshapes created?’, ‘how does the shape relate to the atomic packing and crystallography of the material?’, ‘how can we control and characterize the external shape and crystal structure of such small nanocrystals?’. This feature article aims to give the reader an overview of important techniques, concepts and recent advances related to these questions. Nucleation, growth and how seed crystallography influences the final synthesis product are discussed, followed by shape prediction models based on seed crystallography and thermodynamic or kinetic parameters. The crystallographic implications of epitaxy and orientation in multilayered, core-shell nanoparticles are overviewed, and, finally, the development and implications of novel, spatially resolved analysis tools are discussed. PMID:25485133

  2. Temperature controlled material irradiation in the advanced test reactor

    NASA Astrophysics Data System (ADS)

    Ingram, F. W.; Palmer, A. J.; Stites, D. J.

    1998-10-01

    The United States Department of Energy (US DOE) has initiated the development of an Irradiation Test Vehicle (ITV) for fusion materials irradiation at the Advanced Test Reactor (ATR) in Idaho Falls, Idaho, USA. The ITV is capable of providing neutron spectral tailoring and individual temperature control for up to 15 experiment capsules simultaneously. The test vehicle consists of three In-Pile Tubes (IPTs) running the length of the reactor vessel. These IPTs are kept dry and test trains with integral instrumentation are inserted and removed through a transfer shield plate above the reactor vessel head. The test vehicle is designed to irradiate specimens as large as 2.2 cm in diameter, at temperatures of 250-800°C, achieving neutron damage rates as high as 10 displacements per atom per year. The high fast to thermal neutron flux ratio required for fusion materials testing is accomplished by using an aluminum filler to displace as much water as possible from the flux trap and surrounding the filler piece with a ring of replaceable neutron absorbing material. The gas blend temperature control system remains in place from test to test, thus hardware costs for new tests are limited to the experiment capsule train and integral instrumentation.

  3. Methods for integrating optical fibers with advanced aerospace materials

    NASA Astrophysics Data System (ADS)

    Poland, Stephen H.; May, Russell G.; Murphy, Kent A.; Claus, Richard O.; Tran, Tuan A.; Miller, Mark S.

    1993-07-01

    Optical fibers are attractive candidates for sensing applications in near-term smart materials and structures, due to their inherent immunity to electromagnetic interference and ground loops, their capability for distributed and multiplexed operation, and their high sensitivity and dynamic range. These same attributes also render optical fibers attractive for avionics busses for fly-by-light systems in advanced aircraft. The integration of such optical fibers with metal and composite aircraft and aerospace materials, however, remains a limiting factor in their successful use in such applications. This paper first details methods for the practical integration of optical fiber waveguides and cable assemblies onto and into materials and structures. Physical properties of the optical fiber and coatings which affect the survivability of the fiber are then considered. Mechanisms for the transfer of the strain from matrix to fiber for sensor and data bus fibers integrated with composite structural elements are evaluated for their influence on fiber survivability, in applications where strain or impact is imparted to the assembly.

  4. Functional Hydrogel Materials Inspired by Amyloid

    NASA Astrophysics Data System (ADS)

    Schneider, Joel

    2012-02-01

    Protein assembly resulting in the formation of amyloid fibrils, assemblies rich in cross beta-sheet structure, is normally thought of as a deleterious event associated with disease. However, amyloid formation is also involved in a diverse array of normal biological functions such as cell adhesion, melanin synthesis, insect defense mechanism and modulation of water surface tension by fungi and bacteria. These findings indicate that Nature has evolved to take advantage of large, proteinaceous fibrillar assemblies to elicit function. We are designing functional materials, namely hydrogels, from peptides that self-assembled into fibrillar networks, rich in cross beta-sheet structure. These gels can be used for the direct encapsulation and delivery of small molecule-, protein- and cell-based therapeutics. Loaded gels exhibit shear-thinning/self-healing mechanical properties enabling their delivery via syringe. In addition to their use for delivery, we have found that some of these gels display antibacterial activity. Although cytocompatible towards mammalian cells, the hydrogels can kill a broad spectrum of bacteria on contact.

  5. PREFACE: International Conference on Advanced Materials (ICAM 2015)

    NASA Astrophysics Data System (ADS)

    El-Khateeb, Mohammad Y.

    2015-10-01

    It is with great pleasure to welcome you to the "International Conference of Advanced Materials ICAM 2015" that will take place at Jordan University of Science and Technology (JUST), Irbid, Jordan. This year, the conference coincides with the coming of spring in Jordan; we hope the participants will enjoy the colors and fragrance of April in Jordan. The call for papers attracted submissions of over a hundred abstracts from twenty one different countries. These papers are going to be classified under four plenary lectures, fifteen invited papers, thirty five oral presentations and more than sixty posters covering the different research areas of the conference. The ICAM conference focuses on new advances in research in the field of materials covering chemical, physical and biological aspects. ICAM includes representatives from academia, industry, governmental and private sectors. The plenary and invited speakers will present, discuss, promote and disseminate research in all fields of advanced materials. Topics range from synthesis, applications, and solid state to nano-materials. In addition, talented junior investigators will present their best ongoing research at a poster session. We have also organized several workshops contiguous to the main conference, such as the one-day workshop on "Particle Surface Modification for Improved Applications". The purpose of this short course was to introduce interested materials technologists to several methodologies that have been developed to modify the surfaces of particulate matter. Moreover, a pre-conference workshop on "Communication in Science" was conducted for young scientists. The main goal of this workshop was to train young scientists in matters of interdisciplinary scientific communications. In addition to the scientific program, the attendees will have a chance to discover the beauty of Jordan, a land of rich history and varied culture. Numerous social events that will provide opportunities to renew old contacts and

  6. Advances in remote sensing of vegetation function and traits

    NASA Astrophysics Data System (ADS)

    Houborg, Rasmus; Fisher, Joshua B.; Skidmore, Andrew K.

    2015-12-01

    Remote sensing of vegetation function and traits has advanced significantly over the past half-century in the capacity to retrieve useful plant biochemical, physiological and structural quantities across a range of spatial and temporal scales. However, the translation of remote sensing signals into meaningful descriptors of vegetation function and traits is still associated with large uncertainties due to complex interactions between leaf, canopy, and atmospheric mediums, and significant challenges in the treatment of confounding factors in spectrum-trait relations. This editorial provides (1) a background on major advances in the remote sensing of vegetation, (2) a detailed timeline and description of relevant historical and planned satellite missions, and (3) an outline of remaining challenges, upcoming opportunities and key research objectives to be tackled. The introduction sets the stage for thirteen Special Issue papers here that focus on novel approaches for exploiting current and future advancements in remote sensor technologies. The described enhancements in spectral, spatial and temporal resolution and radiometric performance provide exciting opportunities to significantly advance the ability to accurately monitor and model the state and function of vegetation canopies at multiple scales on a timely basis.

  7. Improved Thermoelectric Devices: Advanced Semiconductor Materials for Thermoelectric Devices

    SciTech Connect

    2009-12-11

    Broad Funding Opportunity Announcement Project: Phononic Devices is working to recapture waste heat and convert it into usable electric power. To do this, the company is using thermoelectric devices, which are made from advanced semiconductor materials that convert heat into electricity or actively remove heat for refrigeration and cooling purposes. Thermoelectric devices resemble computer chips, and they manage heat by manipulating the direction of electrons at the nanoscale. These devices aren’t new, but they are currently too inefficient and expensive for widespread use. Phononic Devices is using a high-performance, cost-effective thermoelectric design that will improve the device’s efficiency and enable electronics manufacturers to more easily integrate them into their products.

  8. Advanced materials for high-temperature solid electrolyte applications

    SciTech Connect

    Bates, J.L.; Chick, L.A.; Weber, W.J.; Youngblood, G.E.

    1990-05-01

    Advanced materials for use as electrodes, interconnections, and electrolytes in high-temperature electrochemical applications are under investigation. The air sinterability of La{sub 1-x}Sr{sub x}CrO{sub 3} is highly dependent upon a synergistic relationship between the (La + Sr)/Cr ratio, cation volatility, and second phase formation and transformation. Electrical conductivity in the ZrO{sub 2}--Y{sub 2}O{sub 3}--CeO{sub 2} and ZrO{sub 2}--Y{sub 2}O{sub 3}--TiO{sub 2} systems is highly dependent on composition and atmosphere. The electrochemical processes that occur at the solid-solid-gas interfaces in La(Sr)MnO{sub 3}/ZrO{sub 2}(Y{sub 2}O{sub 3}) have been studied using an unbonded interface cell and impedance spectroscopy. 6 refs., 7 figs.

  9. A Novel Approach to Material Development for Advanced Reactor Systems

    SciTech Connect

    Was, G.S.; Atzmon, M.; Wang, L.

    1999-12-22

    OAK B188 A Novel Approach to Material Development for Advanced Reactor Systems. Year one of this project had three major goals. First, to specify, order and install a new high current ion source for more rapid and stable proton irradiation. Second, to assess the use low temperature irradiation and chromium pre-enrichment in an effort to isolate a radiation damage microstructure in stainless steels without the effects of RIS. Third, to prepare for the irradiation of reactor pressure vessel steel and Zircaloy. In year 1 quarter 1, the project goal was to order the high current ion source and to procure and prepare samples of stainless steel for low temperature proton irradiation.

  10. A Novel Approach to Material Development for Advanced Reactor Systems

    SciTech Connect

    Was, G.S.; Atzmon, M.; Wang, L.

    2000-06-27

    OAK B188 A Novel Approach to Material Development for Advanced Reactor Systems. Year one of this project had three major goals. First, to specify, order and install a new high current ion source for more rapid and stable proton irradiation. Second, to assess the use of low temperature irradiation and chromium pre-enrichment in an effort to isolate a radiation damage microstructure in stainless steel without the effects of RIS. Third, to initiate irradiation of reactor pressure vessel steel and Zircaloy. In year 1 quarter 3, the project goal was to complete irradiation of model alloys of RPV steels for a range of doses and begin sample characterization. We also planned to prepare samples for microstructure isolation in stainless steels, and to identify sources of Zircaloy for irradiation and characterization.

  11. Functional, Responsive Materials Assembled from Recombinant Oleosin

    NASA Astrophysics Data System (ADS)

    Hammer, Daniel

    Biological cells are surrounded by a plasma membrane made primarily of phospholipids that form a bilayer. This membrane is permselective and compartmentalizes the cell. A simple form of artificial cell is the vesicle, in which a phospholipid bilayer membrane surrounds an aqueous solution. However, there is no a priori reason why a membrane needs to be made of phospholipids. It could be made of any surfactant that forms a bilayer. We have assembled membranes and other structures from the recombinant plant protein oleosin. The ability to assemble from a recombinant protein means that every molecule is identical, we have complete control over the sequence, and hence can build in designer functionality with high fidelity, including adhesion and enzymatic activity. Such incorporation is trivial using the tools of molecular biology. We find that while many variants of oleosin make membranes, others make micelles and sheets. We show how the type of supramolecular structure can be altered by the conditions of solvent, such as ionic strength, and the architecture of the surfactant itself. We show that protease cleavable domains can be incorporated within oleosin, and be engineered to protect other functional domains such as adhesive motifs, to make responsive materials whose activity and shape depend on the action of proteases. We will also present the idea of making ``Franken''-oleosins, where large domains of native oleosin are replaced with domains from other functional proteins, to make hybrids conferred by the donor protein. Thus, we can view oleosin as a template upon which a vast array of designer functionalities can be imparted..

  12. Novel particle and radiation sources and advanced materials

    NASA Astrophysics Data System (ADS)

    Mako, Frederick

    2016-03-01

    The influence Norman Rostoker had on the lives of those who had the pleasure of knowing him is profound. The skills and knowledge I gained as a graduate student researching collective ion acceleration has fueled a career that has evolved from particle beam physics to include particle and radiation source development and advanced materials research, among many other exciting projects. The graduate research performed on collective ion acceleration was extended by others to form the backbone for laser driven plasma ion acceleration. Several years after graduate school I formed FM Technologies, Inc., (FMT), and later Electron Technologies, Inc. (ETI). Currently, as the founder and president of both FMT and ETI, the Rostoker influence can still be felt. One technology that we developed is a self-bunching RF fed electron gun, called the Micro-Pulse Gun (MPG). The MPG has important applications for RF accelerators and microwave tube technology, specifically clinically improved medical linacs and "green" klystrons. In addition to electron beam and RF source research, knowledge of materials and material interactions gained indirectly in graduate school has blossomed into breakthroughs in materials joining technologies. Most recently, silicon carbide joining technology has been developed that gives robust helium leak tight, high temperature and high strength joints between ceramic-to-ceramic and ceramic-to-metal. This joining technology has the potential to revolutionize the ethylene production, nuclear fuel and solar receiver industries by finally allowing for the practical use of silicon carbide as furnace coils, fuel rods and solar receptors, respectively, which are applications that have been needed for decades.

  13. Synthesis of functional materials in combustion reactions

    NASA Astrophysics Data System (ADS)

    Zhuravlev, V. D.; Bamburov, V. G.; Ermakova, L. V.; Lobachevskaya, N. I.

    2015-12-01

    The conditions for obtaining oxide compounds in combustion reactions of nitrates of metals with organic chelating-reducing agents such as amino acids, urea, and polyvinyl alcohol are reviewed. Changing the nature of internal fuels and the reducing agent-to-oxidizing agent ratio makes possible to modify the thermal regime of the process, fractal dimensionality, morphology, and dispersion of synthesized functional materials. This method can be used to synthesize simple and complex oxides, composites, and metal powders, as well as ceramics and coatings. The possibilities of synthesis in combustion reactions are illustrated by examples of αand γ-Al2O3, YSZ composites, uranium oxides, nickel powder, NiO and NiO: YSZ composite, TiO2, and manganites, cobaltites, and aluminates of rare earth elements.

  14. Synthesis of functional materials in combustion reactions

    SciTech Connect

    Zhuravlev, V. D. Bamburov, V. G.; Ermakova, L. V.; Lobachevskaya, N. I.

    2015-12-15

    The conditions for obtaining oxide compounds in combustion reactions of nitrates of metals with organic chelating–reducing agents such as amino acids, urea, and polyvinyl alcohol are reviewed. Changing the nature of internal fuels and the reducing agent-to-oxidizing agent ratio makes possible to modify the thermal regime of the process, fractal dimensionality, morphology, and dispersion of synthesized functional materials. This method can be used to synthesize simple and complex oxides, composites, and metal powders, as well as ceramics and coatings. The possibilities of synthesis in combustion reactions are illustrated by examples of αand γ-Al{sub 2}O{sub 3}, YSZ composites, uranium oxides, nickel powder, NiO and NiO: YSZ composite, TiO{sub 2}, and manganites, cobaltites, and aluminates of rare earth elements.

  15. Functional materials for energy-efficient buildings

    NASA Astrophysics Data System (ADS)

    Ebert, H.-P.

    2015-08-01

    The substantial improving of the energy efficiency is essential to meet the ambitious energy goals of the EU. About 40% of the European energy consumption belongs to the building sector. Therefore the reduction of the energy demand of the existing building stock is one of the key measures to deliver a substantial contribution to reduce CO2-emissions of our society. Buildings of the future have to be efficient in respect to energy consumption for construction and operation. Current research activities are focused on the development of functional materials with outstanding thermal and optical properties to provide, for example, slim thermally superinsulated facades, highly integrated heat storage systems or adaptive building components. In this context it is important to consider buildings as entities which fulfill energy and comfort claims as well as aesthetic aspects of a sustainable architecture.

  16. Multiscale and Multiphysics Modeling of Additive Manufacturing of Advanced Materials

    NASA Technical Reports Server (NTRS)

    Liou, Frank; Newkirk, Joseph; Fan, Zhiqiang; Sparks, Todd; Chen, Xueyang; Fletcher, Kenneth; Zhang, Jingwei; Zhang, Yunlu; Kumar, Kannan Suresh; Karnati, Sreekar

    2015-01-01

    The objective of this proposed project is to research and develop a prediction tool for advanced additive manufacturing (AAM) processes for advanced materials and develop experimental methods to provide fundamental properties and establish validation data. Aircraft structures and engines demand materials that are stronger, useable at much higher temperatures, provide less acoustic transmission, and enable more aeroelastic tailoring than those currently used. Significant improvements in properties can only be achieved by processing the materials under nonequilibrium conditions, such as AAM processes. AAM processes encompass a class of processes that use a focused heat source to create a melt pool on a substrate. Examples include Electron Beam Freeform Fabrication and Direct Metal Deposition. These types of additive processes enable fabrication of parts directly from CAD drawings. To achieve the desired material properties and geometries of the final structure, assessing the impact of process parameters and predicting optimized conditions with numerical modeling as an effective prediction tool is necessary. The targets for the processing are multiple and at different spatial scales, and the physical phenomena associated occur in multiphysics and multiscale. In this project, the research work has been developed to model AAM processes in a multiscale and multiphysics approach. A macroscale model was developed to investigate the residual stresses and distortion in AAM processes. A sequentially coupled, thermomechanical, finite element model was developed and validated experimentally. The results showed the temperature distribution, residual stress, and deformation within the formed deposits and substrates. A mesoscale model was developed to include heat transfer, phase change with mushy zone, incompressible free surface flow, solute redistribution, and surface tension. Because of excessive computing time needed, a parallel computing approach was also tested. In addition

  17. Experimental and computing strategies in advanced material characterization problems

    NASA Astrophysics Data System (ADS)

    Bolzon, G.

    2015-10-01

    The mechanical characterization of materials relies more and more often on sophisticated experimental methods that permit to acquire a large amount of data and, contemporarily, to reduce the invasiveness of the tests. This evolution accompanies the growing demand of non-destructive diagnostic tools that assess the safety level of components in use in structures and infrastructures, for instance in the strategic energy sector. Advanced material systems and properties that are not amenable to traditional techniques, for instance thin layered structures and their adhesion on the relevant substrates, can be also characterized by means of combined experimental-numerical tools elaborating data acquired by full-field measurement techniques. In this context, parameter identification procedures involve the repeated simulation of the laboratory or in situ tests by sophisticated and usually expensive non-linear analyses while, in some situation, reliable and accurate results would be required in real time. The effectiveness and the filtering capabilities of reduced models based on decomposition and interpolation techniques can be profitably used to meet these conflicting requirements. This communication intends to summarize some results recently achieved in this field by the author and her co-workers. The aim is to foster further interaction between engineering and mathematical communities.

  18. Experimental and computing strategies in advanced material characterization problems

    SciTech Connect

    Bolzon, G.

    2015-10-28

    The mechanical characterization of materials relies more and more often on sophisticated experimental methods that permit to acquire a large amount of data and, contemporarily, to reduce the invasiveness of the tests. This evolution accompanies the growing demand of non-destructive diagnostic tools that assess the safety level of components in use in structures and infrastructures, for instance in the strategic energy sector. Advanced material systems and properties that are not amenable to traditional techniques, for instance thin layered structures and their adhesion on the relevant substrates, can be also characterized by means of combined experimental-numerical tools elaborating data acquired by full-field measurement techniques. In this context, parameter identification procedures involve the repeated simulation of the laboratory or in situ tests by sophisticated and usually expensive non-linear analyses while, in some situation, reliable and accurate results would be required in real time. The effectiveness and the filtering capabilities of reduced models based on decomposition and interpolation techniques can be profitably used to meet these conflicting requirements. This communication intends to summarize some results recently achieved in this field by the author and her co-workers. The aim is to foster further interaction between engineering and mathematical communities.

  19. Novel materials for advanced supercapacitors and Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Yushin, Gleb

    2009-11-01

    High power energy storage devices, such as supercapacitors and Li-ion batteries, are critical for the development of zero-emission electrical vehicles, large scale smart grid, and energy efficient cargo ships and locomotives. The energy storage characteristics of supercapacitors and Li-ion batteries are mostly determined by the specific capacities of their electrodes, while their power characteristics are influenced by the maximum rate of the ion transport. The talk will focus on the development of nanocomposite electrodes capable to improve both the energy and power storage characteristics of the state of the art devices. Advanced ultra-high surface area carbons, carbon-polymer, and carbon-metal oxide nanocomposites have been demonstrated to greatly exceed the specific capacitance of traditional electrodes for supercapacitors. In addition, selected materials showed the unprecedented ultra-fast charging and discharging characteristics. Intelligently designed Si-C composites showed up to 5 times higher specific capacity than graphite, the conventional anode material in Li-ion batteries. Achieving stable performance of Si anodes is commonly a challenge. Recent experiments suggest that individual Si nanoparticles and thin films below a critical size do not fracture and exhibit high reversible capacity for Li. The often observed rapid degradation of Si-based anodes is related not to the intrinsic property of Si but to the loss of electrical contact within the anodes caused by the large volume changes that takes place during Li insertion and extraction. Successful synthesis of high capacity nanocomposite Si-C particles that do not exhibit volume changes during Li insertion and extraction allowed us to achieve stable performance. In order to overcome the limitations of traditional composites precise control over the materials' structure and porosity at the nanoscale was required.

  20. Advanced Nanoporous Materials for Micro-Gravimetric Sensing to Trace-Level Bio/Chemical Molecules

    PubMed Central

    Xu, Pengcheng; Li, Xinxin; Yu, Haitao; Xu, Tiegang

    2014-01-01

    Functionalized nanoporous materials have been developed recently as bio/chemical sensing materials. Due to the huge specific surface of the nano-materials for molecular adsorption, high hopes have been placed on gravimetric detection with micro/nano resonant cantilevers for ultra-sensitive sensing of low-concentration bio/chemical substances. In order to enhance selectivity of the gravimetric resonant sensors to the target molecules, it is crucial to modify specific groups onto the pore-surface of the nano-materials. By loading the nanoporous sensing material onto the desired region of the mass-type transducers like resonant cantilevers, the micro-gravimetric bio/chemical sensors can be formed. Recently, such micro-gravimetric bio/chemical sensors have been successfully applied for rapid or on-the-spot detection of various bio/chemical molecules at the trace-concentration level. The applicable nanoporous sensing materials include mesoporous silica, zeolite, nanoporous graphene oxide (GO) and so on. This review article focuses on the recent achievements in design, preparation, functionalization and characterization of advanced nanoporous sensing materials for micro-gravimetric bio/chemical sensing. PMID:25313499

  1. Functional organic materials for electronics industries

    NASA Technical Reports Server (NTRS)

    Shibayama, K.; Ono, H.

    1982-01-01

    Topics closely related with organic, high molecular weight material synthesis are discussed. These are related to applications such as display, recording, sensors, semiconductors, and I.C. correlation. New materials are also discussed. General principles of individual application are not included. Materials discussed include color, electrochromic, thermal recording, organic photoconductors for electrophotography, and photochromic materials.

  2. Recent Advances in Shape Memory Soft Materials for Biomedical Applications.

    PubMed

    Chan, Benjamin Qi Yu; Low, Zhi Wei Kenny; Heng, Sylvester Jun Wen; Chan, Siew Yin; Owh, Cally; Loh, Xian Jun

    2016-04-27

    Shape memory polymers (SMPs) are smart and adaptive materials able to recover their shape through an external stimulus. This functionality, combined with the good biocompatibility of polymers, has garnered much interest for biomedical applications. In this review, we discuss the design considerations critical to the successful integration of SMPs for use in vivo. We also highlight recent work on three classes of SMPs: shape memory polymers and blends, shape memory polymer composites, and shape memory hydrogels. These developments open the possibility of incorporating SMPs into device design, which can lead to vast technological improvements in the biomedical field. PMID:27018814

  3. Cost - The challenge for advanced materials and structures

    NASA Technical Reports Server (NTRS)

    Davis, John G., Jr.; Freeman, William T., Jr.; Siddiqi, Shahid

    1992-01-01

    Information is presented on the cost of various aircraft structures, together with methods for predicting and reducing cost. The need for the development of cost models, and of a comparative cost algorithm which could function as an engineering design tool to evaluate different design concepts, is emphasized. Efforts are underway to develop cost models that establish building-block unit cell elements that represent different material forms, geometric shapes, fabrication processes, and methods of assembly, with the purpose of expressing cost per pound or labor per pound data, with physical design and manufacture variables that a designer can visualize.

  4. Advances in core loss calculations for magnetic materials

    NASA Technical Reports Server (NTRS)

    Triner, J. E.

    1982-01-01

    A new analytical technique which predicts the basic magnetic properties under various operating conditions encountered in state-of-the-art dc-ac/dc converters is discussed. Using a new flux-controlled core excitation circuit, magnetic core characteristics were developed for constant values of ramp flux (square wave voltage excitation) and frequency. From this empirical data, a mathematical loss characteristics equation is developed to analytically predict the specific core loss of several magnetic materials under various waveform excitation conditions. In addition, these characteristics show the circuit designer for the first time the direct functional relatonships between induction level and specific core loss as a function of the two key dc-dc converter operating parameters of input voltage and duty cycle.

  5. Characterization and Application of Colloidal Nanocrystalline Materials for Advanced Photovoltaics

    NASA Astrophysics Data System (ADS)

    Bhandari, Khagendra P.

    Solar energy is Earth's primary source of renewable energy and photovoltaic solar cells enable the direct conversion of sunlight into electricity. Crystalline silicon solar cells and modules have dominated photovoltaic technology from the beginning and they now constitute more than 90% of the PV market. Thin film (CdTe and CIGS) solar cells and modules come in second position in market share. Some organic, dye-sensitized and perovskite solar cells are emerging in the market but are not yet in full commercial scale. Solar cells made from colloidal nanocrystalline materials may eventually provide both low cost and high efficiency because of their promising properties such as high absorption coefficient, size tunable band gap, and quantum confinement effect. It is also expected that the greenhouse gas emission and energy payback time from nanocrystalline solar PV systems will also be least compared to all other types of PV systems mainly due to the least embodied energy throughout their life time. The two well-known junction architectures for the fabrication of quantum dot based photovoltaic devices are the Schottky junction and heterojunction. In Schottky junction cells, a heteropartner semiconducting material is not required. A low work function metal is used as the back contact, a transparent conducting layer is used as the front contact, and the layer of electronically-coupled quantum dots is placed between these two materials. Schottky junction solar cells explain the usefulness of nanocrystalline materials for high efficiency heterojunction solar cells. For heterojunction devices, n-type semiconducting materials such as ZnO , CdS or TiO2 have been used as suitable heteropartners. Here, PbS quantum dot solar cells were fabricated using ZnO and CdS semiconductor films as window layers. Both of the heteropartners are sputter-deposited onto TCO coated glass substrates; ZnO was deposited with the substrate held at room temperature and for CdS the substrate was at 250

  6. Interfacial Properties and Design of Functional Energy Materials

    SciTech Connect

    Sumpter, Bobby G; Liang, Liangbo; Nicolai, Adrien; Meunier, V.

    2014-01-01

    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

  7. Functional neuroimaging of traumatic brain injury: advances and clinical utility

    PubMed Central

    Irimia, Andrei; Van Horn, John Darrell

    2015-01-01

    Functional deficits due to traumatic brain injury (TBI) can have significant and enduring consequences upon patients’ life quality and expectancy. Although functional neuroimaging is essential for understanding TBI pathophysiology, an insufficient amount of effort has been dedicated to the task of translating functional neuroimaging findings into information with clinical utility. The purpose of this review is to summarize the use of functional neuroimaging techniques – especially functional magnetic resonance imaging, diffusion tensor imaging, positron emission tomography, magnetic resonance spectroscopy, and electroencephalography – for advancing current knowledge of TBI-related brain dysfunction and for improving the rehabilitation of TBI patients. We focus on seven core areas of functional deficits, namely consciousness, motor function, attention, memory, higher cognition, personality, and affect, and, for each of these, we summarize recent findings from neuroimaging studies which have provided substantial insight into brain function changes due to TBI. Recommendations are also provided to aid in setting the direction of future neuroimaging research and for understanding brain function changes after TBI. PMID:26396520

  8. Functional Carbon Materials for Electrochemical Energy Storage

    NASA Astrophysics Data System (ADS)

    Zhou, Huihui

    The ability to harvest and convert solar energy has been associated with the evolution of human civilization. The increasing consumption of fossil fuels since the industrial revolution, however, has brought to concerns in ecological deterioration and depletion of the fossil fuels. Facing these challenges, humankind is forced to seek for clean, sustainable and renewable energy resources, such as biofuels, hydraulic power, wind power, geothermal energy and other kinds of alternative energies. However, most alternative energy sources, generally in the form of electrical energy, could not be made available on a continuous basis. It is, therefore, essential to store such energy into chemical energy, which are portable and various applications. In this context, electrochemical energy-storage devices hold great promises towards this goal. The most common electrochemical energy-storage devices are electrochemical capacitors (ECs, also called supercapacitors) and batteries. In comparison to batteries, ECs posses high power density, high efficiency, long cycling life and low cost. ECs commonly utilize carbon as both (symmetric) or one of the electrodes (asymmetric), of which their performance is generally limited by the capacitance of the carbon electrodes. Therefore, developing better carbon materials with high energy density has been emerging as one the most essential challenges in the field. The primary objective of this dissertation is to design and synthesize functional carbon materials with high energy density at both aqueous and organic electrolyte systems. The energy density (E) of ECs are governed by E = CV 2/2, where C is the total capacitance and V is the voltage of the devices. Carbon electrodes with high capacitance and high working voltage should lead to high energy density. In the first part of this thesis, a new class of nanoporous carbons were synthesized for symmetric supercapacitors using aqueous Li2SO4 as the electrolyte. A unique precursor was adopted to

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

    PubMed Central

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

    2013-01-01

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

  10. Using advanced electron microscopy for the characterization of catalytic materials

    NASA Astrophysics Data System (ADS)

    Pyrz, William D.

    Catalysis will continue to be vitally important to the advancement and sustainability of industrialized societies. Unfortunately, the petroleum-based resources that currently fuel the energy and consumer product needs of an advancing society are becoming increasingly difficult and expensive to extract as supplies diminish and the quality of sources degrade. Therefore, the development of sustainable energy sources and the improvement of the carbon efficiency of existing chemical processes are critical. Further challenges require that these initiatives are accomplished in an environmentally friendly fashion since the effects of carbon-based emissions are proving to be a serious threat to global climate stability. In this dissertation, materials being developed for sustainable energy and process improvement initiatives are studied. Our approach is to use materials characterization, namely advanced electron microscopy, to analyze the targeted systems at the nano- or Angstrom-scale with the goal of developing useful relationships between structure, composition, crystalline order, morphology, and catalytic performance. One area of interest is the complex Mo-V-M-O (M=Te, Sb, Ta, Nb) oxide system currently being developed for the selective oxidation/ammoxidation of propane to acrylic acid or acrylonitrile, respectively. Currently, the production of acrylic acid and acrylonitrile rely on propylene-based processes, yet significant cost savings could be realized if the olefin-based feeds could be replaced by paraffin-based ones. The major challenge preventing this feedstock replacement is the development of a suitable paraffin-activating catalyst. Currently, the best candidate is the Mo-V-Nb-Te-O complex oxide catalyst that is composed of two majority phases that are commonly referred to as M1 and M2. However, there is a limited understanding of the roles of each component with respect to how they contribute to catalyst stability and the reaction mechanism. Aberration

  11. Recent Advances in Conjugated Polymer Materials for Disease Diagnosis.

    PubMed

    Lv, Fengting; Qiu, Tian; Liu, Libing; Ying, Jianming; Wang, Shu

    2016-02-10

    The extraordinary optical amplification and light-harvesting properties of conjugated polymers impart sensing systems with higher sensitivity, which meets the primary demands of early cancer diagnosis. Recent advances in the detection of DNA methylation and mutation with polyfluorene derivatives based fluorescence resonance energy transfer (FRET) as a means to modulate fluorescent responses attest to the great promise of conjugated polymers as powerful tools for the clinical diagnosis of diseases. To facilitate the ever-changing needs of diagnosis, the development of detection approaches and FRET signal analysis are highlighted in this review. Due to their exceptional brightness, excellent photostability, and low or absent toxicity, conjugated polymers are verified as superior materials for in-vivo imaging, and provide feasibility for future clinical molecular-imaging applications. The integration of conjugated polymers with clinical research has shown profound effects on diagnosis for the early detection of disease-related biomarkers, as well as in-vivo imaging, which leads to a multidisciplinary scientific field with perspectives in both basic research and application issues. PMID:26679834

  12. Advanced materials based on polymer blends/polymer blend nanocomposites

    NASA Astrophysics Data System (ADS)

    Shikaleska, A. V.; Pavlovska, F. P.

    2012-09-01

    Processability, morphology, mechanical properties and rheological behavior of poly(vinylchloride) (PVC)/poly(ethylmethacrylate) (PEMA) blends and PVC/PEMA/montmorillonite (MMT) composites, prepared by melt processing in a brabender mixer, were studied. Samples were characterized using SEM, mechanical testing, DMTA and a parallel plate rheometer. Plastograms show that there is noticeable drop of fusion times and increase in melt viscosity torque of both, polymer blend and polymer blend nanocomposite, in comparison with those of neat PVC. SEM images show that homogenous dispersions are obtained. Tensile tests indicate that PVC/PEMA and PVC/PEMA/MMT samples have greater tensile strength and elastic modulus and lower elongation compared to PVC. When solid viscoelastic properties are considered (DMTA), slightly higher storage moduli are obtained whereas more prominent increase of storage modulus is observed when nanoclay particles are added in a PVC/PEMA matrix. From the calculated area of tandelta peak of all tested samples, nanocomposites exhibit the lowest damping behavior. Oscillatory measurements in a molten state were used for determining the frequency dependencies of storage G' and loss G" moduli. It was found that G" curves of neat PVC lie above those of G' suggesting that PVC behaves like viscoelastic liquid. Similar results, but with significantly higher values of G' and G" over the whole frequency range for PVC/PEMA blends were obtained. Steady shear measurements show that the presence of PEMA and nanoclay particles increases the shear stress and shear viscosity of neat PVC. In order to define the rheological equations of state the three material functions were determined. According to these functions all samples exhibit shear thinning behavior and the curves obey the power law equation. As rheological behaviour was found to be strongly dependent on blend's micro and macro structure and it is one of the main factors defining the end properties, attempt was

  13. Strongly coupled inorganic/nanocarbon hybrid materials for advanced electrocatalysis.

    PubMed

    Liang, Yongye; Li, Yanguang; Wang, Hailiang; Dai, Hongjie

    2013-02-13

    Electrochemical systems, such as fuel cell and water splitting devices, represent some of the most efficient and environmentally friendly technologies for energy conversion and storage. Electrocatalysts play key roles in the chemical processes but often limit the performance of the entire systems due to insufficient activity, lifetime, or high cost. It has been a long-standing challenge to develop efficient and durable electrocatalysts at low cost. In this Perspective, we present our recent efforts in developing strongly coupled inorganic/nanocarbon hybrid materials to improve the electrocatalytic activities and stability of inorganic metal oxides, hydroxides, sulfides, and metal-nitrogen complexes. The hybrid materials are synthesized by direct nucleation, growth, and anchoring of inorganic nanomaterials on the functional groups of oxidized nanocarbon substrates including graphene and carbon nanotubes. This approach affords strong chemical attachment and electrical coupling between the electrocatalytic nanoparticles and nanocarbon, leading to nonprecious metal-based electrocatalysts with improved activity and durability for the oxygen reduction reaction for fuel cells and chlor-alkali catalysis, oxygen evolution reaction, and hydrogen evolution reaction. X-ray absorption near-edge structure and scanning transmission electron microscopy are employed to characterize the hybrids materials and reveal the coupling effects between inorganic nanomaterials and nanocarbon substrates. Z-contrast imaging and electron energy loss spectroscopy at single atom level are performed to investigate the nature of catalytic sites on ultrathin graphene sheets. Nanocarbon-based hybrid materials may present new opportunities for the development of electrocatalysts meeting the requirements of activity, durability, and cost for large-scale electrochemical applications. PMID:23339685

  14. Recent advances in inorganic materials for LDI-MS analysis of small molecules.

    PubMed

    Shi, C Y; Deng, C H

    2016-05-10

    In this review, various inorganic materials were summarized for the analysis of small molecules by laser desorption/ionization mass spectrometry (LDI-MS). Due to its tremendous advantages, such as simplicity, high speed, high throughput, small analyte volumes and tolerance towards salts, LDI-MS has been widely used in various analytes. During the ionization process, a suitable agent is required to assist the ionization, such as an appropriate matrix for matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS). However, it is normally difficult to analyze small molecules with the MALDI technique because conventional organic matrices may produce matrix-related peaks in the low molecular-weight region, which limits the detection of small molecules (m/z < 700 Da). Therefore, more and more inorganic materials, including carbon-based materials, silicon-based materials and metal-based materials, have been developed to assist the ionization of small molecules. These inorganic materials can transfer energy and improve the ionization efficiency of analytes. In addition, functionalized inorganic materials can act as both an adsorbent and an agent in the enrichment and ionization of small molecules. In this review, we mainly focus on present advances in inorganic materials for the LDI-MS analysis of small molecules in the last five years, which contains the synthetic protocols of novel inorganic materials and the detailed results achieved by inorganic materials. On the other hand, this review also summarizes the application of inorganic materials as adsorbents in the selective enrichment of small molecules, which provides a new field for the application of inorganic materials. PMID:27050451

  15. Advanced materials and concepts for energy storage devices

    NASA Astrophysics Data System (ADS)

    Teng, Shiang Jen

    Over the last decade, technological progress and advances in the miniaturization of electronic devices have increased demands for light-weight, high-efficiency, and carbon-free energy storage devices. These energy storage devices are expected to play important roles in automobiles, the military, power plants, and consumer electronics. Two main types of electrical energy storage systems studied in this research are Li ion batteries and supercapacitors. Several promising solid state electrolytes and supercapacitor electrode materials are investigated in this research. The first section of this dissertation is focused on the novel results on pulsed laser annealing of Li7La3Zr2O12 (LLZO). LLZO powders with a tetragonal structure were prepared by a sol-gel technique, then a pulsed laser annealing process was employed to convert the tetragonal powders to cubic LLZO without any loss of lithium. The second section of the dissertation reports on how Li5La 3Nb2O12 (LLNO) was successfully synthesized via a novel molten salt synthesis (MSS) method at the relatively low temperature of 900°C. The low sintering temperature prevented the loss of lithium that commonly occurs during synthesis using conventional solid state or wet chemical reactions. The second type of energy storage device studied is supercapacitors. Currently, research on supercapacitors is focused on increasing their energy densities and lowering their overall production costs by finding suitable electrode materials. The third section of this dissertation details how carbonized woods electrodes were used as supercapacitor electrode materials. A high energy density of 45.6 Wh/kg and a high power density of 2000 W/kg were obtained from the supercapacitor made from carbonized wood electrodes. The high performance of the supercapacitor was discovered to originate from the hierarchical porous structures of the carbonized wood. Finally, the fourth section of this dissertation is on the electrochemical effects of

  16. Recent advances in the molten salt destruction of energetic materials

    SciTech Connect

    Pruneda, C. O., LLNL

    1996-09-01

    We have demonstrated the use of the Molten Salt Destruction (MSD) Process for destroying explosives, liquid gun propellant, and explosives-contaminated materials on a 1.5 kg of explosive/hr bench- scale unit (1, 2, 3, 4, 5). In our recently constructed 5 kg/hr pilot- scale unit we have also demonstrated the destruction of a liquid gun propellant and simulated wastes containing HMX (octogen). MSD converts the organic constituents of the waste into non-hazardous substances such as carbon dioxide, nitrogen, and water. Any inorganic constituents of the waste, such as metallic particles, are retained in the molten salt. The destruction of energetic materials waste is accomplished by introducing it, together with air, into a vessel containing molten salt (a eutectic mixture of sodium, potassium, and lithium carbonates). The following pure explosives have been destroyed in our bench-scale experimental unit located at Lawrence Livermore National Laboratory`s (LLNL) High Explosives Applications Facility (HEAF): ammonium picrate, HMX, K- 6 (keto-RDX), NQ, NTO, PETN, RDX, TATB, and TNT. In addition, the following compositions were also destroyed: Comp B, LX- IO, LX- 1 6, LX- 17, PBX-9404, and XM46 (liquid gun propellant). In this 1.5 kg/hr bench-scale unit, the fractions of carbon converted to CO and of chemically bound nitrogen converted to NO{sub x} were found to be well below 1%. In addition to destroying explosive powders and compositions we have also destroyed materials that are typical of residues which result from explosives operations. These include shavings from machined pressed parts of plastic-bonded explosives and sump waste containing both explosives and non-explosive debris. Based on the process data obtained on the bench-scale unit we designed and constructed a next-generation 5 kg/hr pilot-scale unit, incorporating LLNL`s advanced chimney design. The pilot unit has completed process implementation operations and explosives safety reviews. To date, in this

  17. Exploring mixed microbial community functioning: recent advances in metaproteomics

    PubMed Central

    Siggins, Alma; Gunnigle, Eoin; Abram, Florence

    2012-01-01

    System approaches to elucidate ecosystem functioning constitute an emerging area of research within microbial ecology. Such approaches aim at investigating all levels of biological information (DNA, RNA, proteins and metabolites) to capture the functional interactions occurring in a given ecosystem and track down characteristics that could not be accessed by the study of isolated components. In this context, the study of the proteins collectively expressed by all the microorganisms present within an ecosystem (metaproteomics) is not only crucial but can also provide insights into microbial functionality. Overall, the success of metaproteomics is closely linked to metagenomics, and with the exponential increase in the availability of metagenome sequences, this field of research is starting to experience generation of an overwhelming amount of data, which requires systematic analysis. Metaproteomics has been employed in very diverse environments, and this review discusses the recent advances achieved in the context of human biology, soil, marine and freshwater environments as well as natural and bioengineered systems. PMID:22225547

  18. Simulating functional magnetic materials on supercomputers.

    PubMed

    Gruner, Markus Ernst; Entel, Peter

    2009-07-22

    The recent passing of the petaflop per second landmark by the Roadrunner project at the Los Alamos National Laboratory marks a preliminary peak of an impressive world-wide development in the high-performance scientific computing sector. Also, purely academic state-of-the-art supercomputers such as the IBM Blue Gene/P at Forschungszentrum Jülich allow us nowadays to investigate large systems of the order of 10(3) spin polarized transition metal atoms by means of density functional theory. Three applications will be presented where large-scale ab initio calculations contribute to the understanding of key properties emerging from a close interrelation between structure and magnetism. The first two examples discuss the size dependent evolution of equilibrium structural motifs in elementary iron and binary Fe-Pt and Co-Pt transition metal nanoparticles, which are currently discussed as promising candidates for ultra-high-density magnetic data storage media. However, the preference for multiply twinned morphologies at smaller cluster sizes counteracts the formation of a single-crystalline L1(0) phase, which alone provides the required hard magnetic properties. The third application is concerned with the magnetic shape memory effect in the Ni-Mn-Ga Heusler alloy, which is a technologically relevant candidate for magnetomechanical actuators and sensors. In this material strains of up to 10% can be induced by external magnetic fields due to the field induced shifting of martensitic twin boundaries, requiring an extremely high mobility of the martensitic twin boundaries, but also the selection of the appropriate martensitic structure from the rich phase diagram. PMID:21828528

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

    NASA Astrophysics Data System (ADS)

    Muthukumar, Vidyalakshmi Chockalingam

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

  20. Place (Material, Metaphorical, Symbolic) in Education History: The Townsville College of Advanced Education Library Resource Centre, 1974-1981

    ERIC Educational Resources Information Center

    Gasparini, Fay; Vick, Malcolm

    2008-01-01

    Place is material, conceptual and symbolic. Physically, the Library at Townsville College of Advanced Education was central, visible and distinctive. Internally, it provided a dramatically different environment from other college buildings. It functioned as the (metaphorical) "hub" of the external studies programme and, when the college was under…

  1. Depleted uranium hexafluoride: The source material for advanced shielding systems

    SciTech Connect

    Quapp, W.J.; Lessing, P.A.; Cooley, C.R.

    1997-02-01

    The U.S. Department of Energy (DOE) has a management challenge and financial liability problem in the form of 50,000 cylinders containing 555,000 metric tons of depleted uranium hexafluoride (UF{sub 6}) that are stored at the gaseous diffusion plants. DOE is evaluating several options for the disposition of this UF{sub 6}, including continued storage, disposal, and recycle into a product. Based on studies conducted to date, the most feasible recycle option for the depleted uranium is shielding in low-level waste, spent nuclear fuel, or vitrified high-level waste containers. Estimates for the cost of disposal, using existing technologies, range between $3.8 and $11.3 billion depending on factors such as the disposal site and the applicability of the Resource Conservation and Recovery Act (RCRA). Advanced technologies can reduce these costs, but UF{sub 6} disposal still represents large future costs. This paper describes an application for depleted uranium in which depleted uranium hexafluoride is converted into an oxide and then into a heavy aggregate. The heavy uranium aggregate is combined with conventional concrete materials to form an ultra high density concrete, DUCRETE, weighing more than 400 lb/ft{sup 3}. DUCRETE can be used as shielding in spent nuclear fuel/high-level waste casks at a cost comparable to the lower of the disposal cost estimates. Consequently, the case can be made that DUCRETE shielded casks are an alternative to disposal. In this case, a beneficial long term solution is attained for much less than the combined cost of independently providing shielded casks and disposing of the depleted uranium. Furthermore, if disposal is avoided, the political problems associated with selection of a disposal location are also avoided. Other studies have also shown cost benefits for low level waste shielded disposal containers.

  2. Application of complex macromolecular architectures for advanced microelectronic materials.

    PubMed

    Hedrick, James L; Magbitang, Teddie; Connor, Eric F; Glauser, Thierry; Volksen, Willi; Hawker, Craig J; Lee, Victor Y; Miller, Robert D

    2002-08-01

    The distinctive features of well-defined, three-dimensional macromolecules with topologies designed to enhance solubility and amplify end-group functionality facilitated nanophase morphologies in mixtures with organosilicates and ultimately nanoporous organosilicate networks. Novel macromolecular architectures including dendritic and star-shaped polymers and organic nanoparticles were prepared by a modular approach from several libraries of building blocks including various generations of dendritic initiators and dendrons, selectively placed to amplify functionality and/or arm number, coupled with living polymerization techniques. Mixtures of an organosilicate and the macromolecular template were deposited, cured, and the phase separation of the organic component, organized the vitrifying organosilicate into nanostructures. Removal of the sacrificial macromolecular template, also denoted as porogen, by thermolysis, yielded the desired nanoporous organosilicate, and the size scale of phase separation was strongly dependent on the chain topology. These materials were designed for use as interlayer, ultra-low dielectric insulators for on-chip applications with dielectric constant values as low as 1.5. The porogen design, chemistry and role of polymer architecture on hybrid and pore morphology will be emphasized. PMID:12203311

  3. Density functional theory in materials science

    PubMed Central

    Neugebauer, Jörg; Hickel, Tilmann

    2013-01-01

    Materials science is a highly interdisciplinary field. It is devoted to the understanding of the relationship between (a) fundamental physical and chemical properties governing processes at the atomistic scale with (b) typically macroscopic properties required of materials in engineering applications. For many materials, this relationship is not only determined by chemical composition, but strongly governed by microstructure. The latter is a consequence of carefully selected process conditions (e.g., mechanical forming and annealing in metallurgy or epitaxial growth in semiconductor technology). A key task of computational materials science is to unravel the often hidden composition–structure–property relationships using computational techniques. The present paper does not aim to give a complete review of all aspects of materials science. Rather, we will present the key concepts underlying the computation of selected material properties and discuss the major classes of materials to which they are applied. Specifically, our focus will be on methods used to describe single or polycrystalline bulk materials of semiconductor, metal or ceramic form. PMID:24563665

  4. Materials and Area of Study for Advanced Placement Program in American History.

    ERIC Educational Resources Information Center

    Santos, Peter A.

    This paper describes and evaluates benefits of advanced placement programs and identifies materials which can help high school history classroom teachers develop effective advanced placement programs. An advanced placement program is defined as a program which requires a student to do extensive research and writing throughout the school year.…

  5. An advanced probabilistic structural analysis method for implicit performance functions

    NASA Technical Reports Server (NTRS)

    Wu, Y.-T.; Millwater, H. R.; Cruse, T. A.

    1989-01-01

    In probabilistic structural analysis, the performance or response functions usually are implicitly defined and must be solved by numerical analysis methods such as finite element methods. In such cases, the most commonly used probabilistic analysis tool is the mean-based, second-moment method which provides only the first two statistical moments. This paper presents a generalized advanced mean value (AMV) method which is capable of establishing the distributions to provide additional information for reliability design. The method requires slightly more computations than the second-moment method but is highly efficient relative to the other alternative methods. In particular, the examples show that the AMV method can be used to solve problems involving non-monotonic functions that result in truncated distributions.

  6. Advanced functional network analysis in the geosciences: The pyunicorn package

    NASA Astrophysics Data System (ADS)

    Donges, Jonathan F.; Heitzig, Jobst; Runge, Jakob; Schultz, Hanna C. H.; Wiedermann, Marc; Zech, Alraune; Feldhoff, Jan; Rheinwalt, Aljoscha; Kutza, Hannes; Radebach, Alexander; Marwan, Norbert; Kurths, Jürgen

    2013-04-01

    Functional networks are a powerful tool for analyzing large geoscientific datasets such as global fields of climate time series originating from observations or model simulations. pyunicorn (pythonic unified complex network and recurrence analysis toolbox) is an open-source, fully object-oriented and easily parallelizable package written in the language Python. It allows for constructing functional networks (aka climate networks) representing the structure of statistical interrelationships in large datasets and, subsequently, investigating this structure using advanced methods of complex network theory such as measures for networks of interacting networks, node-weighted statistics or network surrogates. Additionally, pyunicorn allows to study the complex dynamics of geoscientific systems as recorded by time series by means of recurrence networks and visibility graphs. The range of possible applications of the package is outlined drawing on several examples from climatology.

  7. The Materials Data Facility: Data Services to Advance Materials Science Research

    NASA Astrophysics Data System (ADS)

    Blaiszik, B.; Chard, K.; Pruyne, J.; Ananthakrishnan, R.; Tuecke, S.; Foster, I.

    2016-07-01

    With increasingly strict data management requirements from funding agencies and institutions, expanding focus on the challenges of research replicability, and growing data sizes and heterogeneity, new data needs are emerging in the materials community. The materials data facility (MDF) operates two cloud-hosted services, data publication and data discovery, with features to promote open data sharing, self-service data publication and curation, and encourage data reuse, layered with powerful data discovery tools. The data publication service simplifies the process of copying data to a secure storage location, assigning data a citable persistent identifier, and recording custom (e.g., material, technique, or instrument specific) and automatically-extracted metadata in a registry while the data discovery service will provide advanced search capabilities (e.g., faceting, free text range querying, and full text search) against the registered data and metadata. The MDF services empower individual researchers, research projects, and institutions to (I) publish research datasets, regardless of size, from local storage, institutional data stores, or cloud storage, without involvement of third-party publishers; (II) build, share, and enforce extensible domain-specific custom metadata schemas; (III) interact with published data and metadata via representational state transfer (REST) application program interfaces (APIs) to facilitate automation, analysis, and feedback; and (IV) access a data discovery model that allows researchers to search, interrogate, and eventually build on existing published data. We describe MDF's design, current status, and future plans.

  8. Photochemical Strategies for the Synthesis of Advanced Materials

    NASA Astrophysics Data System (ADS)

    Billone, Paul S.

    This thesis describes the study of a variety of nanoscale materials and the development of novel synthetic strategies for their production. While the focus and bulk of this study have been directed specifically at subwavelength lithography, a significant portion of this thesis research involves nanoparticle synthesis, characterization, and functionalization. Put in very simple terms, optical lithography is a process where a beam of light, focused in a specific pattern, is used to generate a physical pattern on a solid substrate. This technology forms the basis for almost all microchip production in the world at the present time. As demand for faster and more powerful chips increases, the need to further miniaturize the patterns while minimizing cost has become very important. Multiple photochemical systems were developed in the search for non-reciprocal photochemistry at 193 nm to increase the resolution of lithographic processes at that wavelength. One approach, based on anthracene sensitization of sulfonium salts for acid generation, used photochemically reversible 4+4 aromatic cycloaddition reactions to introduce the non-linear photochemistry. A second approach took advantage of the photochemistry of N-methylphenothiazine and provided the first true example of a lithographically-relevant multi-photon acid generating process. Since all of the systems we studied used sulfonium salts as the acid generating species, we also looked at the photochemistry of the salts themselves. We evaluated the structural effects of the salts on their direct photochemistry and the implications for sensitized multi-photon photochemistry. We found that the identity of the anion plays a significant role in both processes and propose a new photochemical mechanism for acid generation that involves a charge transfer excitation process. We also describe the synthesis and characterization of novel fluorescent silver nanoparticles, both in solution and polymer films. We show that the

  9. Analysis of the influence of advanced materials for aerospace products R&D and manufacturing cost

    NASA Astrophysics Data System (ADS)

    Shen, A. W.; Guo, J. L.; Wang, Z. J.

    2015-12-01

    In this paper, we pointed out the deficiency of traditional cost estimation model about aerospace products Research & Development (R&D) and manufacturing based on analyzing the widely use of advanced materials in aviation products. Then we put up with the estimating formulas of cost factor, which representing the influences of advanced materials on the labor cost rate and manufacturing materials cost rate. The values ranges of the common advanced materials such as composite materials, titanium alloy are present in the labor and materials two aspects. Finally, we estimate the R&D and manufacturing cost of F/A-18, F/A- 22, B-1B and B-2 aircraft based on the common DAPCA IV model and the modified model proposed by this paper. The calculation results show that the calculation precision improved greatly by the proposed method which considering advanced materials. So we can know the proposed method is scientific and reasonable.

  10. Advanced Inverter Functions to Support High Levels of Distributed Solar: Policy and Regulatory Considerations (Brochure)

    SciTech Connect

    Not Available

    2014-11-01

    This paper explains how advanced inverter functions (sometimes called 'smart inverters') contribute to the integration of high levels of solar PV generation onto the electrical grid and covers the contributions of advanced functions to maintaining grid stability. Policy and regulatory considerations associated with the deployment of advanced inverter functions are also introduced.

  11. ADVANCED CERAMIC MATERIALS FOR NEXT-GENERATION NUCLEAR APPLICATIONS

    SciTech Connect

    Marra, J.

    2010-09-29

    proliferation), the worldwide community is working to develop and deploy new nuclear energy systems and advanced fuel cycles. These new nuclear systems address the key challenges and include: (1) extracting the full energy value of the nuclear fuel; (2) creating waste solutions with improved long term safety; (3) minimizing the potential for the misuse of the technology and materials for weapons; (4) continually improving the safety of nuclear energy systems; and (5) keeping the cost of energy affordable.

  12. Cost/benefit analysis of advanced materials technologies for future aircraft turbine engines

    NASA Technical Reports Server (NTRS)

    Bisset, J. W.

    1976-01-01

    The cost/benefits of advance commercial gas turbine materials are described. Development costs, estimated payoffs and probabilities of success are discussed. The materials technologies investigated are: (1) single crystal turbine blades, (2) high strength hot isostatic pressed turbine disk, (3) advanced oxide dispersion strengthened burner liner, (4) bore entry cooled hot isostatic pressed turbine disk, (5) turbine blade tip - outer airseal system, and (6) advance turbine blade alloys.

  13. Validation of an Advanced Material Model for Simulating the Impact and Shock Response of Composite Materials

    NASA Astrophysics Data System (ADS)

    Clegg, Richard A.; Hayhurst, Colin J.; Nahme, Hartwig

    2001-06-01

    Validation of an advanced continuum based numerical model for the simulation of the shock response of composite materials during high rate transient dynamic loading is described. The constitutive model, implemented in AUTODYN-2D and 3D, allows for the representation of non-linear shock effects in combination with orthotropic stiffness and damage. Simulations of uniaxial flyer plate experiments on aramid and polyethylene fibre composite systems are presented and compared with experiment. The continuum model is shown to reproduce well the experimental VISAR velocity traces at the rear surface of the targets. Finally, practical application of the model as implemented in AUTODYN is demonstrated through the simulation of ballistic and hypervelocity impact events. Comparison with experiment is given where possible.

  14. Advanced silk material spun by a transgenic silkworm promotes cell proliferation for biomedical application.

    PubMed

    Wang, Feng; Xu, Hanfu; Wang, Yuancheng; Wang, Riyuan; Yuan, Lin; Ding, Huan; Song, Chunnuan; Ma, Sanyuan; Peng, Zhixin; Peng, Zhangchuan; Zhao, Ping; Xia, Qingyou

    2014-12-01

    Natural silk fiber spun by the silkworm Bombyx mori is widely used not only for textile materials, but also for biofunctional materials. In the present study, we genetically engineered an advanced silk material, named hSFSV, using a transgenic silkworm, in which the recombinant human acidic fibroblast growth factor (hFGF1) protein was specifically synthesized in the middle silk gland and secreted into the sericin layer to surround the silk fiber using our previously optimized sericin1 expression system. The content of the recombinant hFGF1 in the hSFSV silk was estimated to be approximate 0.07% of the cocoon shell weight. The mechanical properties of hSFSV raw silk fiber were enhanced slightly compared to those of the wild-type raw silk fiber, probably due to the presence of the recombinant of hFGF1 in the sericin layer. Remarkably, the hSFSV raw silk significantly stimulated the cell growth and proliferation of NIH/3T3 mouse embryonic fibroblast cells, suggesting that the mitogenic activity of recombinant hFGF1 was well maintained and functioned in the sericin layer of hSFSV raw silk. These results show that the genetically engineered raw silk hSFSV could be used directly as a fine biomedical material for mass application. In addition, the strategy whereby functional recombinant proteins are expressed in the sericin layer of silk might be used to create more genetically engineered silks with various biofunctions and applications. PMID:24980060

  15. Surface-functionalized mesoporous carbon materials

    DOEpatents

    Dai, Sheng; Gorka, Joanna; Mayes, Richard T.

    2016-02-02

    A functionalized mesoporous carbon composition comprising a mesoporous carbon scaffold having mesopores in which polyvinyl polymer grafts are covalently attached, wherein said mesopores have a size of at least 2 nm and up to 50 nm. Also described is a method for producing the functionalized mesoporous composition, wherein a reaction medium comprising a precursor mesoporous carbon, vinyl monomer, initiator, and solvent is subjected to sonication of sufficient power to result in grafting and polymerization of the vinyl monomer into mesopores of the precursor mesoporous carbon. Also described are methods for using the functionalized mesoporous carbon, particularly in extracting metal ions from metal-containing solutions.

  16. Imparting the unique properties of DNA into complex material architectures and functions

    PubMed Central

    Xu, Phyllis F.; Noh, Hyunwoo; Lee, Ju Hun; Domaille, Dylan W.; Nakatsuka, Matthew A.; Goodwin, Andrew P.; Cha, Jennifer N.

    2014-01-01

    While the remarkable chemical and biological properties of DNA have been known for decades, these properties have only been imparted into materials with unprecedented function much more recently. The inimitable ability of DNA to form programmable, complex assemblies through stable, specific, and reversible molecular recognition has allowed the creation of new materials through DNA’s ability to control a material’s architecture and properties. In this review we discuss recent progress in how DNA has brought unmatched function to materials, focusing specifically on new advances in delivery agents, devices, and sensors. PMID:25525408

  17. Advanced characterization of hysteretic materials by object-oriented software

    NASA Astrophysics Data System (ADS)

    Ionita, V.; Gavrila, H.

    2002-04-01

    A new object-oriented software, which is dedicated for the characterization of magnetic materials, including the hysteresis effect, is presented. The product allows the development and utilization of an information base, containing experimental and numerical data related to the magnetic material behaviour. The materials may be modelled with different hysteresis models (Preisach, Jiles-Atherton, etc.).

  18. Liquid-assisted laser ablation of advanced ceramics and glass-ceramic materials

    NASA Astrophysics Data System (ADS)

    Garcia-Giron, A.; Sola, D.; Peña, J. I.

    2016-02-01

    In this work, results obtained by laser ablation of advanced ceramics and glass-ceramic materials assisted by liquids are reported. A Q-switched Nd:YAG laser at its fundamental wavelength of 1064 nm with pulse-width in the nanosecond range was used to machine the materials, which were immersed in water and ethylene glycol. Variation in geometrical parameters, morphology, and ablation yields were studied by using the same laser working conditions. It was observed that machined depth and removed volume depended on the thermal, optical, and mechanical features of the processed materials as well as on the properties of the surrounding medium in which the laser processing was carried out. Variation in ablation yields was studied in function of the liquid used to assist the laser process and related to refractive index and viscosity. Material features and working conditions were also related to the obtained results in order to correlate ablation parameters with respect to the hardness of the processed materials.

  19. Advances in Materials Science for Environmental and Energy Technologies II

    SciTech Connect

    Matyas, Dr Josef; Ohji, Tatsuki; Liu, Xingbo; Paranthaman, Mariappan Parans; Devanathan, Ram; Fox, Kevin; Singh, Mrityunjay; Wong-ng, Winnie

    2013-01-01

    The Materials Science and Technology 2012 Conference and Exhibition (MS&T'12) was held October 7-11, 2012, in Pittsburgh, Pennsylvania. One of the major themes of the conference was Environmental and Energy Issues. Papers from five of the symposia held under that theme are invluded in this volume. These symposia included Materials Issues in Nuclear Waste Management for the 21st Century; Green Technologies for Materials Manufacturing and Processing IV; Energy Storage: Materials, Systems and Applications; Energy Conversion-Photovoltaic, Concentraing Solar Power and Thermoelectric; and Materials Development for Nuclear Applications and Extreme Environments.

  20. Synthesis and characterization of inorganic nanostructured materials for advanced energy storage

    NASA Astrophysics Data System (ADS)

    Xie, Jin

    The performance of advanced energy storage devices is intimately connected to the designs of electrodes. To enable significant developments in this research field, we need detailed information and knowledge about how the functions and performances of the electrodes depend on their chemical compositions, dimensions, morphologies, and surface properties. This thesis presents my successes in synthesizing and characterizing electrode materials for advanced electrochemical energy storage devices, with much attention given to understanding the operation and fading mechanism of battery electrodes, as well as methods to improve their performances and stabilities. This dissertation is presented within the framework of two energy storage technologies: lithium ion batteries and lithium oxygen batteries. The energy density of lithium ion batteries is determined by the density of electrode materials and their lithium storage capabilities. To improve the overall energy densities of lithium ion batteries, silicon has been proposed to replace lithium intercalation compounds in the battery anodes. However, with a ~400% volume expansion upon fully lithiation, silicon-based anodes face serious capacity degradation in battery operation. To overcome this challenge, heteronanostructure-based Si/TiSi2 were designed and synthesized as anode materials for lithium ion batteries with long cycling life. The performance and morphology relationship was also carefully studied through comparing one-dimensional and two-dimensional heteronanostructure-based silicon anodes. Lithium oxygen batteries, on the other hand, are devices based on lithium conversion chemistries and they offer higher energy densities compared to lithium ion batteries. However, existing carbon based electrodes in lithium oxygen batteries only allow for battery operation with limited capacity, poor stability and low round-trip efficiency. The degradation of electrolytes and carbon electrodes have been found to both contribute

  1. Part A - Advanced turbine systems. Part B - Materials/manufacturing element of the Advanced Turbine Systems Program

    SciTech Connect

    Karnitz, M.A.

    1996-06-01

    The DOE Offices of Fossil Energy and Energy Efficiency and Renewable Energy have initiated a program to develop advanced turbine systems for power generation. The objective of the Advanced Turbine Systems (ATS) Program is to develop ultra-high efficiency, environmentally superior, and cost competitive gas turbine systems for utility and industrial applications. One of the supporting elements of the ATS Program is the Materials/Manufacturing Technologies Task. The objective of this element is to address the critical materials and manufacturing issues for both industrial and utility gas turbines.

  2. Bio-inspired Propulsion with Functionally Graded Materials

    NASA Astrophysics Data System (ADS)

    Schleicher, William; Floryan, Daniel; van Buren, Tyler; Smits, Alexander; Moored, Keith; Lehigh University Team; Priceton University Team

    2015-11-01

    From an engineering perspective, biological swimmers are a composite material system with varying material properties across their propulsors. These material properties govern how the swimmer's structure interacts with its surrounding fluid. A two dimensional boundary element fluid solver is strongly coupled to a direct, implicit, geometrically non-linear structure solver to study the effects of functionally graded materials. A zeroth order functionally graded material approximation is used, where a rigid material abruptly meets a flexible material. Thrust, input power, and propulsive efficiency are studied as functions of non-dimensional frequency, reduced frequency, Strouhal number, flexion ratio, and effective stiffness. The numerical results are compared to experimental results for zero attack angle cases, building confidence in the numerical model. The results are further compared to structurally rigid materials. Supported by the Office of Naval Research under Program Director Dr. Bob Brizzolara, MURI grant number N00014-14-1-0533.

  3. Functional toxicology: tools to advance the future of toxicity testing.

    PubMed

    Gaytán, Brandon D; Vulpe, Chris D

    2014-01-01

    The increased presence of chemical contaminants in the environment is an undeniable concern to human health and ecosystems. Historically, by relying heavily upon costly and laborious animal-based toxicity assays, the field of toxicology has often neglected examinations of the cellular and molecular mechanisms of toxicity for the majority of compounds-information that, if available, would strengthen risk assessment analyses. Functional toxicology, where cells or organisms with gene deletions or depleted proteins are used to assess genetic requirements for chemical tolerance, can advance the field of toxicity testing by contributing data regarding chemical mechanisms of toxicity. Functional toxicology can be accomplished using available genetic tools in yeasts, other fungi and bacteria, and eukaryotes of increased complexity, including zebrafish, fruit flies, rodents, and human cell lines. Underscored is the value of using less complex systems such as yeasts to direct further studies in more complex systems such as human cell lines. Functional techniques can yield (1) novel insights into chemical toxicity; (2) pathways and mechanisms deserving of further study; and (3) candidate human toxicant susceptibility or resistance genes. PMID:24847352

  4. Building a functional multiple intelligences theory to advance educational neuroscience.

    PubMed

    Cerruti, Carlo

    2013-01-01

    A key goal of educational neuroscience is to conduct constrained experimental research that is theory-driven and yet also clearly related to educators' complex set of questions and concerns. However, the fields of education, cognitive psychology, and neuroscience use different levels of description to characterize human ability. An important advance in research in educational neuroscience would be the identification of a cognitive and neurocognitive framework at a level of description relatively intuitive to educators. I argue that the theory of multiple intelligences (MI; Gardner, 1983), a conception of the mind that motivated a past generation of teachers, may provide such an opportunity. I criticize MI for doing little to clarify for teachers a core misunderstanding, specifically that MI was only an anatomical map of the mind but not a functional theory that detailed how the mind actually processes information. In an attempt to build a "functional MI" theory, I integrate into MI basic principles of cognitive and neural functioning, namely interregional neural facilitation and inhibition. In so doing I hope to forge a path toward constrained experimental research that bears upon teachers' concerns about teaching and learning. PMID:24391613

  5. Building a functional multiple intelligences theory to advance educational neuroscience

    PubMed Central

    Cerruti, Carlo

    2013-01-01

    A key goal of educational neuroscience is to conduct constrained experimental research that is theory-driven and yet also clearly related to educators’ complex set of questions and concerns. However, the fields of education, cognitive psychology, and neuroscience use different levels of description to characterize human ability. An important advance in research in educational neuroscience would be the identification of a cognitive and neurocognitive framework at a level of description relatively intuitive to educators. I argue that the theory of multiple intelligences (MI; Gardner, 1983), a conception of the mind that motivated a past generation of teachers, may provide such an opportunity. I criticize MI for doing little to clarify for teachers a core misunderstanding, specifically that MI was only an anatomical map of the mind but not a functional theory that detailed how the mind actually processes information. In an attempt to build a “functional MI” theory, I integrate into MI basic principles of cognitive and neural functioning, namely interregional neural facilitation and inhibition. In so doing I hope to forge a path toward constrained experimental research that bears upon teachers’ concerns about teaching and learning. PMID:24391613

  6. Functional toxicology: tools to advance the future of toxicity testing

    PubMed Central

    Gaytán, Brandon D.; Vulpe, Chris D.

    2014-01-01

    The increased presence of chemical contaminants in the environment is an undeniable concern to human health and ecosystems. Historically, by relying heavily upon costly and laborious animal-based toxicity assays, the field of toxicology has often neglected examinations of the cellular and molecular mechanisms of toxicity for the majority of compounds—information that, if available, would strengthen risk assessment analyses. Functional toxicology, where cells or organisms with gene deletions or depleted proteins are used to assess genetic requirements for chemical tolerance, can advance the field of toxicity testing by contributing data regarding chemical mechanisms of toxicity. Functional toxicology can be accomplished using available genetic tools in yeasts, other fungi and bacteria, and eukaryotes of increased complexity, including zebrafish, fruit flies, rodents, and human cell lines. Underscored is the value of using less complex systems such as yeasts to direct further studies in more complex systems such as human cell lines. Functional techniques can yield (1) novel insights into chemical toxicity; (2) pathways and mechanisms deserving of further study; and (3) candidate human toxicant susceptibility or resistance genes. PMID:24847352

  7. Research Update: Towards designed functionalities in oxide-based electronic materials

    SciTech Connect

    Rondinelli, James M.; Poeppelmeier, Kenneth R.; Zunger, Alex

    2015-08-01

    One of the grand challenges facing materials-by-design approaches for complex oxide deployment in electronic devices is how to balance transformative first-principles based predictions with experimental feasibility. Here, we briefly review the functionality-driven approach (inverse design) for materials discovery, encapsulated in three modalities for materials discovery (m{sup 3}D) that integrate experimental feedback. We compare it to both traditional theoretical and high-throughput database-directed approaches aimed at advancing oxide-based materials into technologies.

  8. Polymeric nanotherapeutics: clinical development and advances in stealth functionalization strategies

    NASA Astrophysics Data System (ADS)

    Hu, Che-Ming J.; Fang, Ronnie H.; Luk, Brian T.; Zhang, Liangfang

    2013-12-01

    Long-circulating polymeric nanotherapeutics have garnered increasing interest in research and in the clinic owing to their ability to improve the solubility and pharmacokinetics of therapeutic cargoes. Modulation of carrier properties promises more effective drug localization at the disease sites and can lead to enhanced drug safety and efficacy. In the present review, we highlight the current development of polymeric nanotherapeutics in the clinic. In light of the importance of stealth properties in therapeutic nanoparticles, we also review the advances in stealth functionalization strategies and examine the performance of different stealth polymers in the literature. In addition, we discuss the recent development of biologically inspired ``self'' nanoparticles, which present a differing stealth concept from conventional approaches.

  9. Characterization and development of materials for advanced textile composites

    NASA Technical Reports Server (NTRS)

    Hartness, J. Timothy; Greene, Timothy L.; Taske, Leo E.

    1993-01-01

    Work ongoing under the NASA Langley - Advanced Composite Technology (ACT) program is discussed. The primary emphasis of the work centers around the development and characterization of graphite fiber that has been impregnated with an epoxy powder. Four epoxies have been characterized in towpreg form as to their weaveability and braidability. Initial mechanical properties have been generated on each resin system. These include unidirectional as well as 8-harness satin cloth. Initial 2D and 3D weaving and braiding trials will be reported on as well as initial efforts to develop towpreg suitable for advanced tow placement.

  10. Life prediction of advanced materials for gas turbine application

    SciTech Connect

    Zamrik, S.Y.; Ray, A.; Koss, D.A.

    1995-10-01

    Most of the studies on the low cycle fatigue life prediction have been reported under isothermal conditions where the deformation of the material is strain dependent. In the development of gas turbines, components such as blades and vanes are exposed to temperature variations in addition to strain cycling. As a result, the deformation process becomes temperature and strain dependent. Therefore, the life of the component becomes sensitive to temperature-strain cycling which produces a process known as {open_quotes}thermomechanical fatigue, or TMF{close_quotes}. The TMF fatigue failure phenomenon has been modeled using conventional fatigue life prediction methods, which are not sufficiently accurate to quantitatively establish an allowable design procedure. To add to the complexity of TMF life prediction, blade and vane substrates are normally coated with aluminide, overlay or thermal barrier type coatings (TBC) where the durability of the component is dominated by the coating/substrate constitutive response and by the fatigue behavior of the coating. A number of issues arise from TMF depending on the type of temperature/strain phase cycle: (1) time-dependent inelastic behavior can significantly affect the stress response. For example, creep relaxation during a tensile or compressive loading at elevated temperatures leads to a progressive increase in the mean stress level under cyclic loading. (2) the mismatch in elastic and thermal expansion properties between the coating and the substrate can lead to significant deviations in the coating stress levels due to changes in the elastic modulii. (3) the {open_quotes}dry{close_quotes} corrosion resistance coatings applied to the substrate may act as primary crack initiation sites. Crack initiation in the coating is a function of the coating composition, its mechanical properties, creep relaxation behavior, thermal strain range and the strain/temperature phase relationship.

  11. Solid state nuclear magnetic resonance investigations of advanced energy materials

    NASA Astrophysics Data System (ADS)

    Bennett, George D.

    In order to better understand the physical electrochemical changes that take place in lithium ion batteries and asymmetric hybrid supercapacitors solid state nuclear magnetic resonance (NMR) spectroscopy has been useful to probe and identify changes on the atomic and molecular level. NMR is used to characterize the local environment and investigate the dynamical properties of materials used in electrochemical storage devices (ESD). NMR investigations was used to better understand the chemical composition of the solid electrolyte interphase which form on the negative and positive electrodes of lithium batteries as well as identify the breakdown products that occur in the operation of the asymmetric hybrid supercapacitors. The use of nano-structured particles in the development of new materials causes changes in the electrical, structural and other material properties. NMR was used to investigate the affects of fluorinated and non fluorinated single wall nanotubes (SWNT). In this thesis three experiments were performed using solid state NMR samples to better characterize them. The electrochemical reactions of a lithium ion battery determine its operational profile. Numerous means have been employed to enhance battery cycle life and operating temperature range. One primary means is the choice and makeup of the electrolyte. This study focuses on the characteristics of the solid electrolyte interphase (SEI) that is formed on the electrodes surface during the charge discharge cycle. The electrolyte in this study was altered with several additives in order to determine the influence of the additives on SEI formation as well as the intercalation and de-intercalation of lithium ions in the electrodes. 7Li NMR studies where used to characterize the SEI and its composition. Solid state NMR studies of the carbon enriched acetonitrile electrolyte in a nonaqueous asymmetric hybrid supercapacitor were performed. Magic angle spinning (MAS) coupled with cross polarization NMR

  12. New materials and functionality in spintronics devices

    NASA Astrophysics Data System (ADS)

    Shah, Lubna R.

    The next generation of electronics devices, known as spintronics, which incorporate the spin property of the carriers in combination with their charge degree of freedom is the focus of to-date research. Therefore, exciting new classes of materials have been emerging for the last few years for the development of spintronics devices. This study has been carried out to understand/control various properties of such materials at the fundamental level which is important for the spintronics devices applications. Materials studied here include magnetic semiconductors, magnetostrictive alloys and magnetic tunnel junctions (MTJ) based sensors. In the first part, a comparative study of the room temperature ferromagnetism of Co doped ZnO and CeO2 is presented with emphasis on the role of dopant, defects and host oxide. Systemic structural, magnetic, and transport analyses reveal that the nature of donor defects and host oxide plays a vital role in establishing ferromagnetism. This study provides an insight into the underlying mechanisms responsible for the ferromagnetism in Co-ZnO and Co-CeO 2. Moreover, the discussed exchange mechanisms are in good agreement with the electronic structure calculation of magnetic impurity ions and defects. Composite materials with strong magneto-electric (ME) coupling require magnetic thin films with large saturation magnetostriction constant at low magnetic fields. In the second part of this dissertation, we have studied FeGa alloys where changes in their microstructure with the incorporation of boron occur. These changes make this material a soft magnetic alloy (coercivity ˜ 2 Oe) which has a narrow ferromagnetic resonance (FMR) line width, large magnetostriction and high saturation magnetization. The anisotropy values have been extracted from study of the angular dependence of FMR. This work highlights the role of crystalline anisotropy and induced uniaxial anisotropy which determine the magnetic softness and enhanced magnetostriction at

  13. Advanced copper/low-k IC devices: Packaging process development and materials integrtion

    NASA Astrophysics Data System (ADS)

    Chungpaiboonpatana, Surasit

    Cu/low-k technology provides a number of key advantages including higher interconnect density, improved electrical performance, enhanced thermal performance, and reduced cost. Nevertheless, Cu/low-k IC technology poses many challenges to the packaging industry today. Specifically, low-k dielectric is much more fragile mechanically and copper surfaces are readily oxidized thereby weakening their adhesion to the ILD/metallization layers. The purpose of the study is to provide integrated and reliable materials and process solutions for the packaging of advanced Cu/low-k devices through fundamental materials science understanding. Novel solutions for advanced wirebond and flip-chip technologies are developed, along with resolutions for local and global material interaction issues. The zero-th packaging level study examines a novel direct gold wirebonding onto the Cu/low-k terminal pad structure. The first packaging level study attempts to eliminate the Cu/low-k wiresweeping issue through assembly material interactions with both bonding and transfer molding processes. The second packaging level study exams at the impact of Cu/low-k and processing material implementations on the copper trace cracking failures at the substrate level of a package. An integrated first and second level study on high performance flip chip technology using 8M Cu/low-k silicon chip is performed by the optimization of the underfill and substrate materials selections. Lastly, electromigration phenomena and corrosion mechanisms of copper metallization are developed for biased stressing assembly environment through the fundamental of electrochemistry. Throughout the experiment, the 90/130nm technology node of copper wafer fabrication using Black Diamond low-k dielectric is implemented in several large form-factor package assemblies. Functional test vehicles are assembled, reliability-stressed, and failure-analyzed according to the JEDEC standards for the validity of the integrated materials

  14. Bricklaying Curriculum: Advanced Bricklaying Techniques. Instructional Materials. Revised.

    ERIC Educational Resources Information Center

    Turcotte, Raymond J.; Hendrix, Laborn J.

    This curriculum guide is designed to assist bricklaying instructors in providing performance-based instruction in advanced bricklaying. Included in the first section of the guide are units on customized or architectural masonry units; glass block; sills, lintels, and copings; and control (expansion) joints. The next two units deal with cut,…

  15. Advanced Industrial Materials Program. Annual progress report, FY 1993

    SciTech Connect

    Stooksbury, F.

    1994-06-01

    Mission of the AIM program is to commercialize new/improved materials and materials processing methods that will improve energy efficiency, productivity, and competitiveness. Program investigators in the DOE national laboratories are working with about 100 companies, including 15 partners in CRDAs. Work is being done on intermetallic alloys, ceramic composites, metal composites, polymers, engineered porous materials, and surface modification. The program supports other efforts in the Office of Industrial Technologies to assist the energy-consuming process industries. The aim of the AIM program is to bring materials from basic research to industrial application to strengthen the competitive position of US industry and save energy.

  16. Composite magnetostrictive materials for advanced automotive magnetomechanical sensors

    NASA Astrophysics Data System (ADS)

    McCallum, R. W.; Dennis, K. W.; Jiles, D. C.; Snyder, J. E.; Chen, Y. H.

    2001-04-01

    In this paper we present the development of a composite magnetostrictive material for automotive applications. The material is based on cobalt ferrite, CoOṡFe2O3, and contains a small fraction of metallic matrix phase that serves both as a liquid-phase sintering aid during processing and enhances the mechanical properties over those of a simple sintered ferrite ceramic. In addition the metal matrix makes it possible to braze the material, making the assembly of a sensor relatively simple. The material exhibits good sensitivity and should have high corrosion resistance, while at the same time it is low in cost.

  17. Creep and fatigue research efforts on advanced materials

    NASA Technical Reports Server (NTRS)

    Gayda, John

    1987-01-01

    Two of the more important materials problems encountered in turbine blades of aircraft engines are creep and fatigue. To withstand these high-temperature phenomena modern engines utilize single-crystal, nickel-based superalloys as the material of choice in critical applications. Recent research activities at Lewis on single-crystal blading material as well as future research initiatives on metal matrix composites related to creep and fatigue are discussed. The goal of these research efforts is improving the understanding of microstructure-property relationships and thereby guide material development.

  18. Creep and fatigue research efforts on advanced materials

    NASA Technical Reports Server (NTRS)

    Gayda, John

    1990-01-01

    Two of the more important materials problems encountered in turbine blades of aircraft engines are creep and fatigue. To withstand these high-temperature phenomena, modern engines utilize single-crystal, nickel-base superalloys as the material of choice in critical applications. This paper will present recent research activities at NASA's Lewis Research Center on single-crystal blading material, related to creep and fatique. The goal of these research efforts is to improve the understanding of microstructure-property relationships and thereby guide material development.

  19. Advanced materials for high-temperature thermoelectric energy conversion

    NASA Technical Reports Server (NTRS)

    Vining, Cronin B.; Vandersande, Jan W.; Wood, Charles

    1992-01-01

    A number of refractory semiconductors are under study at the Jet Propulsion Laboratory for application in thermal to electric energy conversion for space power. The main thrust of the program is to improve or develop materials of high figure of merit and, therefore, high conversion efficiencies over a broad temperature range. Materials currently under investigation are represented by silicon-germanium alloys, lanthanum telluride, and boron carbide. The thermoelectric properties of each of these materials, and prospects for their further improvements, are discussed. Continued progress in thermoelectric materials technology can be expected to yield reliable space power systems with double to triple the efficiency of current state of the art systems.

  20. 29 CFR 1208.4 - Material relating to representation function.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 4 2012-07-01 2012-07-01 false Material relating to representation function. 1208.4 Section 1208.4 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD AVAILABILITY OF INFORMATION § 1208.4 Material relating to representation function. (a) The documents constituting the...

  1. 29 CFR 1208.4 - Material relating to representation function.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Material relating to representation function. 1208.4 Section 1208.4 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD AVAILABILITY OF INFORMATION § 1208.4 Material relating to representation function. (a) The documents constituting the...

  2. 29 CFR 1208.4 - Material relating to representation function.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 4 2013-07-01 2013-07-01 false Material relating to representation function. 1208.4 Section 1208.4 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD AVAILABILITY OF INFORMATION § 1208.4 Material relating to representation function. (a) The documents constituting the...

  3. 29 CFR 1208.4 - Material relating to representation function.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 4 2011-07-01 2011-07-01 false Material relating to representation function. 1208.4 Section 1208.4 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD AVAILABILITY OF INFORMATION § 1208.4 Material relating to representation function. (a) The documents constituting the record of a case, such as the notices of...

  4. 29 CFR 1208.4 - Material relating to representation function.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 4 2014-07-01 2014-07-01 false Material relating to representation function. 1208.4 Section 1208.4 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD AVAILABILITY OF INFORMATION § 1208.4 Material relating to representation function. (a) The documents constituting the...

  5. Harvesting Vibrational Energy Using Material Work Functions

    NASA Astrophysics Data System (ADS)

    Varpula, Aapo; Laakso, Sampo J.; Havia, Tahvo; Kyynäräinen, Jukka; Prunnila, Mika

    2014-10-01

    Vibration energy harvesters scavenge energy from mechanical vibrations to energise low power electronic devices. In this work, we report on vibration energy harvesting scheme based on the charging phenomenon occurring naturally between two bodies with different work functions. Such work function energy harvester (WFEH) is similar to electrostatic energy harvester with the fundamental distinction that neither external power supplies nor electrets are needed. A theoretical model and description of different operation modes of WFEHs are presented. The WFEH concept is tested with macroscopic experiments, which agree well with the model. The feasibility of miniaturizing WFEHs is shown by simulating a realistic MEMS device. The WFEH can be operated as a charge pump that pushes charge and energy into an energy storage element. We show that such an operation mode is highly desirable for applications and that it can be realised with either a charge shuttle or with switches. The WFEH is shown to give equal or better output power in comparison to traditional electrostatic harvesters. Our findings indicate that WFEH has great potential in energy harvesting applications.

  6. Harvesting Vibrational Energy Using Material Work Functions

    PubMed Central

    Varpula, Aapo; Laakso, Sampo J.; Havia, Tahvo; Kyynäräinen, Jukka; Prunnila, Mika

    2014-01-01

    Vibration energy harvesters scavenge energy from mechanical vibrations to energise low power electronic devices. In this work, we report on vibration energy harvesting scheme based on the charging phenomenon occurring naturally between two bodies with different work functions. Such work function energy harvester (WFEH) is similar to electrostatic energy harvester with the fundamental distinction that neither external power supplies nor electrets are needed. A theoretical model and description of different operation modes of WFEHs are presented. The WFEH concept is tested with macroscopic experiments, which agree well with the model. The feasibility of miniaturizing WFEHs is shown by simulating a realistic MEMS device. The WFEH can be operated as a charge pump that pushes charge and energy into an energy storage element. We show that such an operation mode is highly desirable for applications and that it can be realised with either a charge shuttle or with switches. The WFEH is shown to give equal or better output power in comparison to traditional electrostatic harvesters. Our findings indicate that WFEH has great potential in energy harvesting applications. PMID:25348004

  7. Near net shape processing: A necessity for advanced materials applications

    NASA Technical Reports Server (NTRS)

    Kuhn, Howard A.

    1993-01-01

    High quality discrete parts are the backbones for successful operation of equipment used in transportation, communication, construction, manufacturing, and appliances. Traditional shapemaking for discrete parts is carried out predominantly by machining, or removing unwanted material to produce the desired shape. As the cost and complexity of modern materials escalates, coupled with the expense and environmental hazards associated with handling of scrap, it is increasingly important to develop near net shape processes for these materials. Such processes involve casting of liquid materials, consolidation of powder materials, or deformation processing of simple solid shapes into the desired shape. Frequently, several of these operations may be used in sequence to produce a finished part. The processes for near net shape forming may be applied to any type of material, including metals, polymers, ceramics, and their composites. The ability to produce shapes is the key to implementation of laboratory developments in materials science into real world applications. This seminar presents an overview of near net shapemaking processes, some application examples, current developments, and future research opportunities.

  8. Computational predictions of energy materials using density functional theory

    NASA Astrophysics Data System (ADS)

    Jain, Anubhav; Shin, Yongwoo; Persson, Kristin A.

    2016-01-01

    In the search for new functional materials, quantum mechanics is an exciting starting point. The fundamental laws that govern the behaviour of electrons have the possibility, at the other end of the scale, to predict the performance of a material for a targeted application. In some cases, this is achievable using density functional theory (DFT). In this Review, we highlight DFT studies predicting energy-related materials that were subsequently confirmed experimentally. The attributes and limitations of DFT for the computational design of materials for lithium-ion batteries, hydrogen production and storage materials, superconductors, photovoltaics and thermoelectric materials are discussed. In the future, we expect that the accuracy of DFT-based methods will continue to improve and that growth in computing power will enable millions of materials to be virtually screened for specific applications. Thus, these examples represent a first glimpse of what may become a routine and integral step in materials discovery.

  9. 10 CFR 37.77 - Advance notification of shipment of category 1 quantities of radioactive material.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... of radioactive material. 37.77 Section 37.77 Energy NUCLEAR REGULATORY COMMISSION PHYSICAL PROTECTION OF CATEGORY 1 AND CATEGORY 2 QUANTITIES OF RADIOACTIVE MATERIAL Physical Protection in Transit § 37.77 Advance notification of shipment of category 1 quantities of radioactive material. As specified...

  10. Advanced composites: Fabrication processes for selected resin matrix materials

    NASA Technical Reports Server (NTRS)

    Welhart, E. K.

    1976-01-01

    This design note is based on present state of the art for epoxy and polyimide matrix composite fabrication technology. Boron/epoxy and polyimide and graphite/epoxy and polyimide structural parts can be successfully fabricated. Fabrication cycles for polyimide matrix composites have been shortened to near epoxy cycle times. Nondestructive testing has proven useful in detecting defects and anomalies in composite structure elements. Fabrication methods and tooling materials are discussed along with the advantages and disadvantages of different tooling materials. Types of honeycomb core, material costs and fabrication methods are shown in table form for comparison. Fabrication limits based on tooling size, pressure capabilities and various machining operations are also discussed.

  11. Recent Advances in Materials for All-Ceramic Restorations

    PubMed Central

    Griggs, Jason A.

    2010-01-01

    SYNOPSIS The past three years of research on materials for all-ceramic veneers, inlays, onlays, single-unit crowns, and multi-unit restorations are reviewed. The primary changes in the field were the proliferation of zirconia-based frameworks and computer-aided fabrication of prostheses, as well as, a trend toward more clinically relevant in vitro test methods. This report includes an overview of ceramic fabrication methods, suggestions for critical assessment of material property data, and a summary of clinical longevity for prostheses constructed of various materials. PMID:17586152

  12. Advanced Modeling and Materials in Kraft Pulp Mills

    SciTech Connect

    Keiser, J.R.; Gorog, J.P.

    2002-05-15

    This CRADA provided technical support to the Weyerhaeuser Company on a number of issues related to the performance and/or selection of materials at a number of locations in a pulp and paper mill. The studies related primarily to components for black liquor recovery boilers, but some effort was directed toward black liquor gasifiers and rolls for paper machines. The purpose of this CRADA was to assist Weyerhaeuser in the evaluation of materials exposed in various paper mill environments and to provide direction in the selection of alternate materials, when appropriate.

  13. Functional oxide nanobelts - from materials to nanodevices

    NASA Astrophysics Data System (ADS)

    Lin, Zhong; Wang

    2003-11-01

    Nanowire and nanotube based materials have been demonstrated as building blocks for nanocircuits, nanosystems and nano-optoelectronics. Recently, ultra-long belt-like, quasi-one-dimensional nanostructures (so called nanobelts or nanoribbons) have been successfully synthesized for semiconducting oxides of zinc, tin, indium, cadmium and gallium, by simply evaporating the desired commercial metal oxide powders at high temperatures [1]. The as-synthesized oxide nanobelts are pure, structurally uniform, single crystalline and most of them free from dislocations; they have a rectangular-like cross-section with typical widths of 30 - 300 nm, width-to-thickness ratios of 5 - 10 and lengths of up to a few millimeters. The belt-like morphology appears to be a unique and common structural characteristic for the family of semiconducting oxides with cations of different valence states and materials of distinct crystallographic structures. Using the technique demonstrated for measuring the mechanical properties of carbon nanotubes based on in-situ transmission electron microscopy [2,3], the bending modulus of the oxide nanobelts has been measured and the nanobelt is shown to be a dual mode nanoresonator for NEMS technology. Field effect transistors [4] and ultra-sensitive nano-size gas sensors [5], nanoresonators and nanocantilevers [6] have also been fabricated based on individual nanobelts. Thermal transport along the nanobelt has also been measured. Nanocantilevers based on nanobelts have been fabricated. Very recently, structurally nanobelts exhibiting piezoelectric and ferroelectric properties have been synthesized, which could be a candidate for nano-scale traducers, actuators and sensors. [1] Z.W. Pan, Z.R. Dai and Z.L. Wang, Science, 209 (2001) 1947. [2] P. Poncharal, Z.L. Wang, D. Ugarte and W.A. de Heer, Science, 283 (1999) 1513; Electron Microscopy of Nanotubes, ed. Z.L. Wang and C. Hui, Kluwer Academic Publisher (2003). [3] R.P. Gao, Z.L. Wang, Z.G. Bai, W. de Heer

  14. Solid State Ionics Advanced Materials for Emerging Technologies

    NASA Astrophysics Data System (ADS)

    Chowdari, B. V. R.; Careem, M. A.; Dissanayake, M. A. K. L.; Rajapakse, R. M. G.; Seneviratne, V. A.

    2006-06-01

    SiO[symbol]) ceramics via solid state sintering of Zr)[symbol] and SiO[symbol] and the effect of dopants on the zircon yield / U. Dhanayake, B. S. B. Karunaratne. Preparation and properties of vanadium doped ZnTe cermet thin films / M. S. Hossain, R. Islam, K. A. Khan. Dynamical properties and electronic structure of lithium-ion conductor / M. Kobayashi ... [et al.]. Cuprous ion conducting Montmorillonite-Polypyrrole nanocomposites / D. M. M. Krishantha ... [et al.]. Frequency dependence of conductivity studies on a newly synthesized superionic solid solution/mixed system: [0.75AgI: 0.25AgCl] / R. K. Nagarch, R. Kumar. Diffuse X-ray and neutron scattering from Powder PbS / X. Lian ... [et al.]. Electron affinity and work function of Pyrolytic MnO[symbol] thin films prepared from Mn(C[symbol]H[symbol]O[symbol])[symbol].4H[symbol]) / A. K. M. Farid Ul Islam, R. Islam, K. A. Khan. Crystal structure and heat capacity of Ba[symbol]Ca[symbol]Nb[symbol]O[symbol] / T. Shimoyama ... [et al.]. XPS and impedance investigations on amorphous vanadium oxide thin films / M. Kamalanathan ... [et al.]. Sintering and mixed electronic-ionic conducting properties of La[symbol]Sr[symbol]NiO[symbol] derived from a polyaminocarboxylate complex precursor / D.-P. Huang ... [et al.]. Preparation and characteristics of ball milled MgH[symbol] + M (M= Fe, VF[symbol] and FeF[symbol]) nanocomposites for hydrogen storage / N. W. B. Balasooriya, Ch. Poinsignon. Structural studies of oxysulfide glasses by X-ray diffraction and molecular dynamics simulation / R. Prasada Rao, M. Seshasayee, J. Dheepa. Synthesis, sintering and oxygen ionic conducting properties of Bi[symbol]V[symbol]Cu[symbol]O[symbol] / F. Zhang ... [et al.]. Synthesis and transport characteristics of PbI[symbol]-Ag[symbol]O-Cr[symbol]O[symbol] superioninc system / S. A. Suthanthiraraj, V. Mathew. Electronic conductivity of La[symbol]Sr[symbol]Ga[symbol]Mg[symbol]Co[symbol]O[symbol] electrolytes / K. Yamaji ... [et al.] -- pt. II. Electrode materials

  15. Metal-Organic Frameworks as Platforms for Functional Materials.

    PubMed

    Cui, Yuanjing; Li, Bin; He, Huajun; Zhou, Wei; Chen, Banglin; Qian, Guodong

    2016-03-15

    Discoveries of novel functional materials have played very important roles to the development of science and technologies and thus to benefit our daily life. Among the diverse materials, metal-organic framework (MOF) materials are rapidly emerging as a unique type of porous and organic/inorganic hybrid materials which can be simply self-assembled from their corresponding inorganic metal ions/clusters with organic linkers, and can be straightforwardly characterized by various analytical methods. In terms of porosity, they are superior to other well-known porous materials such as zeolites and carbon materials; exhibiting extremely high porosity with surface area up to 7000 m(2)/g, tunable pore sizes, and metrics through the interplay of both organic and inorganic components with the pore sizes ranging from 3 to 100 Å, and lowest framework density down to 0.13 g/cm(3). Such unique features have enabled metal-organic frameworks to exhibit great potentials for a broad range of applications in gas storage, gas separations, enantioselective separations, heterogeneous catalysis, chemical sensing and drug delivery. On the other hand, metal-organic frameworks can be also considered as organic/inorganic self-assembled hybrid materials, we can take advantages of the physical and chemical properties of both organic and inorganic components to develop their functional optical, photonic, and magnetic materials. Furthermore, the pores within MOFs can also be utilized to encapsulate a large number of different species of diverse functions, so a variety of functional MOF/composite materials can be readily synthesized. In this Account, we describe our recent research progress on pore and function engineering to develop functional MOF materials. We have been able to tune and optimize pore spaces, immobilize specific functional groups, and introduce chiral pore environments to target MOF materials for methane storage, light hydrocarbon separations, enantioselective recognitions

  16. Multi-functional electrospun nanofibres for advances in tissue regeneration, energy conversion & storage, and water treatment.

    PubMed

    Peng, Shengjie; Jin, Guorui; Li, Linlin; Li, Kai; Srinivasan, Madhavi; Ramakrishna, Seeram; Chen, Jun

    2016-03-01

    Tissue regeneration, energy conversion & storage, and water treatment are some of the most critical challenges facing humanity in the 21st century. In order to address such challenges, one-dimensional (1D) materials are projected to play a key role in developing emerging solutions for the increasingly complex problems. Eletrospinning technology has been demonstrated to be a simple, versatile, and cost-effective method in fabricating a rich variety of materials with 1D nanostructures. These include polymers, composites, and inorganic materials with unique chemical and physical properties. In this tutorial review, we first give a brief introduction to electrospun materials with a special emphasis on the design, fabrication, and modification of 1D functional materials. Adopting the perspective of chemists and materials scientists, we then focus on the recent significant progress made in the domains of tissue regeneration (e.g., skin, nerve, heart and bone) and conversion & storage of clean energy (e.g., solar cells, fuel cells, batteries, and supercapacitors), where nanofibres have been used as active nanomaterials. Furthermore, this review's scope also includes the advances in the use of electrospun materials for the removal of heavy metal ions, organic pollutants, gas and bacteria in water treatment applications. Finally a conclusion and perspective is provided, in which we discuss the remaining challenges for 1D electrospun nanomaterials in tissue regeneration, energy conversion & storage, and water treatment. PMID:26727278

  17. Progress in advanced high temperature turbine materials, coatings, and technology

    NASA Technical Reports Server (NTRS)

    Freche, J. C.; Ault, G. M.

    1977-01-01

    Material categories as well as coatings and recent turbine cooling developments are reviewed. Current state of the art is identified, and as assessment, when appropriate, of progress, problems, and future directions is provided.

  18. Inspection of composite materials with an advanced ultrasonic flaw detector

    NASA Astrophysics Data System (ADS)

    Yamamoto, W.

    The structures and shapes of the composite material products are described. Methods of ultrasonic wave detection are described. New damage detection equipment for laminate and honeycomb structures is addressed.

  19. Thermal interface materials: advancements for "beating the heat" in microelectronics.

    SciTech Connect

    Galloway, Jeffrey A.; Rae, David F.; Rightley, Michael J.; Emerson, John Allen

    2005-05-01

    As electronic assemblies become more compact and with increased processing bandwidth, the escalating thermal energy has become more difficult to manage. The major limitation has been nonmetallic joining using poor thermal interface materials.

  20. Development of Processing Techniques for Advanced Thermal Protection Materials

    NASA Technical Reports Server (NTRS)

    Selvaduray, Guna; Lacson, Jamie; Collazo, Julian

    1997-01-01

    During the period June 1, 1996 through May 31, 1997, the main effort has been in the development of materials for high temperature applications. Thermal Protection Systems (TPS) are constantly being tested and evaluated for thermal shock resistance, high temperature dimensional stability, and tolerance to environmental effects. Materials development was carried out by using many different instruments and methods, ranging from intensive elemental analysis to testing the physical attributes of a material. The material development concentrated on two key areas: (1) development of coatings for carbon/carbon composites, and (2) development of ultra-high temperature ceramics (UHTC). This report describes the progress made in these two areas of research during this contract period.

  1. Advances in monoliths and related porous materials for microfluidics.

    PubMed

    Knob, Radim; Sahore, Vishal; Sonker, Mukul; Woolley, Adam T

    2016-05-01

    In recent years, the use of monolithic porous polymers has seen significant growth. These materials present a highly useful support for various analytical and biochemical applications. Since their introduction, various approaches have been introduced to produce monoliths in a broad range of materials. Simple preparation has enabled their easy implementation in microchannels, extending the range of applications where microfluidics can be successfully utilized. This review summarizes progress regarding monoliths and related porous materials in the field of microfluidics between 2010 and 2015. Recent developments in monolith preparation, solid-phase extraction, separations, and catalysis are critically discussed. Finally, a brief overview of the use of these porous materials for analysis of subcellular and larger structures is given. PMID:27190564

  2. Advance assessment for movement of Haz Cat 3 radioactive materials.

    SciTech Connect

    Vosburg, Susan K.

    2010-04-01

    The current packaging of most HC-3 radioactive materials at SNL/NM do not meet DOT requirements for offsite shipment. SNL/NM is transporting HC-3 quantities of radioactive materials from their storage locations in the Manzano Nuclear Facilities bunkers to facilities in TA-5 to be repackaged for offsite shipment. All transportation of HC-3 rad material by SNL/NM is onsite (performed within the confines of KAFB). Transport is performed only by the Regulated Waste/Nuclear Material Disposition Department. Part of the HC3T process is to provide the CAT with the following information at least three days prior to the move: (1) RFt-Request for transfer; (2) HC3T movement report; (3) Radiological survey; and (4) Transportation Route Map.

  3. Solid State Ionics Advanced Materials for Emerging Technologies

    NASA Astrophysics Data System (ADS)

    Chowdari, B. V. R.; Careem, M. A.; Dissanayake, M. A. K. L.; Rajapakse, R. M. G.; Seneviratne, V. A.

    2006-06-01

    SiO[symbol]) ceramics via solid state sintering of Zr)[symbol] and SiO[symbol] and the effect of dopants on the zircon yield / U. Dhanayake, B. S. B. Karunaratne. Preparation and properties of vanadium doped ZnTe cermet thin films / M. S. Hossain, R. Islam, K. A. Khan. Dynamical properties and electronic structure of lithium-ion conductor / M. Kobayashi ... [et al.]. Cuprous ion conducting Montmorillonite-Polypyrrole nanocomposites / D. M. M. Krishantha ... [et al.]. Frequency dependence of conductivity studies on a newly synthesized superionic solid solution/mixed system: [0.75AgI: 0.25AgCl] / R. K. Nagarch, R. Kumar. Diffuse X-ray and neutron scattering from Powder PbS / X. Lian ... [et al.]. Electron affinity and work function of Pyrolytic MnO[symbol] thin films prepared from Mn(C[symbol]H[symbol]O[symbol])[symbol].4H[symbol]) / A. K. M. Farid Ul Islam, R. Islam, K. A. Khan. Crystal structure and heat capacity of Ba[symbol]Ca[symbol]Nb[symbol]O[symbol] / T. Shimoyama ... [et al.]. XPS and impedance investigations on amorphous vanadium oxide thin films / M. Kamalanathan ... [et al.]. Sintering and mixed electronic-ionic conducting properties of La[symbol]Sr[symbol]NiO[symbol] derived from a polyaminocarboxylate complex precursor / D.-P. Huang ... [et al.]. Preparation and characteristics of ball milled MgH[symbol] + M (M= Fe, VF[symbol] and FeF[symbol]) nanocomposites for hydrogen storage / N. W. B. Balasooriya, Ch. Poinsignon. Structural studies of oxysulfide glasses by X-ray diffraction and molecular dynamics simulation / R. Prasada Rao, M. Seshasayee, J. Dheepa. Synthesis, sintering and oxygen ionic conducting properties of Bi[symbol]V[symbol]Cu[symbol]O[symbol] / F. Zhang ... [et al.]. Synthesis and transport characteristics of PbI[symbol]-Ag[symbol]O-Cr[symbol]O[symbol] superioninc system / S. A. Suthanthiraraj, V. Mathew. Electronic conductivity of La[symbol]Sr[symbol]Ga[symbol]Mg[symbol]Co[symbol]O[symbol] electrolytes / K. Yamaji ... [et al.] -- pt. II. Electrode materials

  4. Recent Advances in Pulp Capping Materials: An Overview

    PubMed Central

    Qureshi, Asma; E., Soujanya; Nandakumar; Pratapkumar; Sambashivarao

    2014-01-01

    Emphasis has shifted from the “doomed” organ concept of an exposed pulp to one of hope and recovery. The era of vital-pulp therapy has been greatly enhanced with the introduction of various pulp capping materials. The aim of this article is to summarize and discuss about the various and newer pulp capping materials used for protection of the dentin-pulp complex. PMID:24596805

  5. Advanced and In Situ Analytical Methods for Solar Fuel Materials.

    PubMed

    Chan, Candace K; Tüysüz, Harun; Braun, Artur; Ranjan, Chinmoy; La Mantia, Fabio; Miller, Benjamin K; Zhang, Liuxian; Crozier, Peter A; Haber, Joel A; Gregoire, John M; Park, Hyun S; Batchellor, Adam S; Trotochaud, Lena; Boettcher, Shannon W

    2016-01-01

    In situ and operando techniques can play important roles in the development of better performing photoelectrodes, photocatalysts, and electrocatalysts by helping to elucidate crucial intermediates and mechanistic steps. The development of high throughput screening methods has also accelerated the evaluation of relevant photoelectrochemical and electrochemical properties for new solar fuel materials. In this chapter, several in situ and high throughput characterization tools are discussed in detail along with their impact on our understanding of solar fuel materials. PMID:26267386

  6. Advances in Suture Material for Obstetric and Gynecologic Surgery

    PubMed Central

    Greenberg, James A; Clark, Rachel M

    2009-01-01

    Despite millennia of experience with wound closure biomaterials, no study or surgeon has yet identified the perfect suture for all situations. Tissue characteristics, tensile strength, reactivity, absorption rates, and handling properties should be taken into account when selecting a wound closure suture. This review discusses the wound healing process and the biomechanical properties of currently available suture materials to better understand how to choose suture material in obstetrics and gynecology. PMID:19826572

  7. Advanced techniques for characterization of ion beam modified materials

    DOE PAGESBeta

    Zhang, Yanwen; Debelle, Aurélien; Boulle, Alexandre; Kluth, Patrick; Tuomisto, Filip

    2014-10-30

    Understanding the mechanisms of damage formation in materials irradiated with energetic ions is essential for the field of ion-beam materials modification and engineering. Utilizing incident ions, electrons, photons, and positrons, various analysis techniques, including Rutherford backscattering spectrometry (RBS), electron RBS, Raman spectroscopy, high-resolution X-ray diffraction, small-angle X-ray scattering, and positron annihilation spectroscopy, are routinely used or gaining increasing attention in characterizing ion beam modified materials. The distinctive information, recent developments, and some perspectives in these techniques are reviewed in this paper. Applications of these techniques are discussed to demonstrate their unique ability for studying ion-solid interactions and the corresponding radiationmore » effects in modified depths ranging from a few nm to a few tens of μm, and to provide information on electronic and atomic structure of the materials, defect configuration and concentration, as well as phase stability, amorphization and recrystallization processes. Finally, such knowledge contributes to our fundamental understanding over a wide range of extreme conditions essential for enhancing material performance and also for design and synthesis of new materials to address a broad variety of future energy applications.« less

  8. Advanced techniques for characterization of ion beam modified materials

    SciTech Connect

    Zhang, Yanwen; Debelle, Aurélien; Boulle, Alexandre; Kluth, Patrick; Tuomisto, Filip

    2014-10-30

    Understanding the mechanisms of damage formation in materials irradiated with energetic ions is essential for the field of ion-beam materials modification and engineering. Utilizing incident ions, electrons, photons, and positrons, various analysis techniques, including Rutherford backscattering spectrometry (RBS), electron RBS, Raman spectroscopy, high-resolution X-ray diffraction, small-angle X-ray scattering, and positron annihilation spectroscopy, are routinely used or gaining increasing attention in characterizing ion beam modified materials. The distinctive information, recent developments, and some perspectives in these techniques are reviewed in this paper. Applications of these techniques are discussed to demonstrate their unique ability for studying ion-solid interactions and the corresponding radiation effects in modified depths ranging from a few nm to a few tens of μm, and to provide information on electronic and atomic structure of the materials, defect configuration and concentration, as well as phase stability, amorphization and recrystallization processes. Finally, such knowledge contributes to our fundamental understanding over a wide range of extreme conditions essential for enhancing material performance and also for design and synthesis of new materials to address a broad variety of future energy applications.

  9. Surface functionalized mesoporous material and method of making same

    DOEpatents

    Feng, Xiangdong [West Richland, WA; Liu, Jun [West Richland, WA; Fryxell, Glen E [Kennewick, WA

    2001-12-04

    According to the present invention, an organized assembly of functional molecules with specific interfacial functionality (functional group(s)) is attached to available surfaces including within mesopores of a mesoporous material. The method of the present invention avoids the standard base soak that would digest the walls between the mesopores by boiling the mesoporous material in water for surface preparation then removing all but one or two layers of water molecules on the internal surface of a pore. Suitable functional molecule precursor is then applied to permeate the hydrated pores and the precursor then undergoes condensation to form the functional molecules on the interior surface(s) of the pore(s).

  10. The use of functionally gradient materials in medicine

    NASA Astrophysics Data System (ADS)

    Narayan, Roger J.; Hobbs, Linn W.; Jin, Chunming; Rabiei, Afsaneh

    2006-07-01

    Functionally gradient materials are characterized by uniform changes in composition, crystallinity, and/or grain structure, which may provide unique biological, chemical, or mechanical functionalities in next-generation medical devices. In this article, the development of functionally gradient Zr-Nb alloys, hydroxyapatite coatings, and diamondlike carbon-metal coatings for medical applications is reviewed.

  11. Continued advancement of laser damage resistant optically functional microstructures

    NASA Astrophysics Data System (ADS)

    Hobbs, Douglas S.; MacLeod, Bruce D.; Sabatino, Ernest

    2012-11-01

    Micro- and nano-structured optically functional surface textures continue to exhibit higher performance and longer term survivability than thin-film coatings for an increasing number of materials used within high energy laser (HEL) systems. Anti-reflection (AR) microstructures (ARMs) produce a graded refractive index yielding high transmission over wide spectral ranges along with a chemical, mechanical and laser damage resistance inherited from the bulk optic material. In this study, ARMs were fabricated in the relevant HEL materials sapphire, neodymium-doped YAG, fused silica, BK7 glass, and the magnesium aluminate known as SPINEL. Standardized pulsed laser induced damage threshold (LiDT) measurements were made using commercial testing services to directly compare the damage resistance of ARMs-treated optics to uncoated and thin-film-AR-coated (TFARC) optics at wavelengths of 532nm, 694nm, 800nm, 1064nm, and 1538nm. As found with prior work, the LiDT of ARMs etched in fused silica was typically in the range of 35 J/cm2 at a wavelength of 1064nm and a pulse width of 10ns, a level that is comparable to uncoated samples and 3.5 times greater than the level specified by six prominent TFARC providers. The Army Research Laboratory measured the pulsed LiDT at 532nm (10ns) of ARMs in fused silica to be up to 5 times the level of the ion beam sputtered TFARC previously employed in their HEL system, and 2 times higher than a low performance single layer MgF2 TFARC. This result was repeated and expanded using a commercial LiDT testing service for ARMs in two types of fused silica and for Schott N-BK7 glass. An average damage threshold of 26.5 J/cm2 was recorded for the ARMs-treated glass materials, a level 4 times higher than the commercial IBS TFARCs tested.

  12. Fabrication of advanced electrochemical energy materials using sol-gel processing techniques

    NASA Technical Reports Server (NTRS)

    Chu, C. T.; Chu, Jay; Zheng, Haixing

    1995-01-01

    Advanced materials play an important role in electrochemical energy devices such as batteries, fuel cells, and electrochemical capacitors. They are being used as both electrodes and electrolytes. Sol-gel processing is a versatile solution technique used in fabrication of ceramic materials with tailored stoichiometry, microstructure, and properties. The application of sol-gel processing in the fabrication of advanced electrochemical energy materials will be presented. The potentials of sol-gel derived materials for electrochemical energy applications will be discussed along with some examples of successful applications. Sol-gel derived metal oxide electrode materials such as V2O5 cathodes have been demonstrated in solid-slate thin film batteries; solid electrolytes materials such as beta-alumina for advanced secondary batteries had been prepared by the sol-gel technique long time ago; and high surface area transition metal compounds for capacitive energy storage applications can also be synthesized with this method.

  13. Advanced computational research in materials processing for design and manufacturing

    SciTech Connect

    Zacharia, T.

    1994-12-31

    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.

  14. Materials issues in some advanced forming techniques, including superplasticity

    SciTech Connect

    Wadsworth, J.; Henshall, G.A.; Nieh, T.G.

    1995-08-22

    From mechanics and macroscopic viewpoints, the sensitivity of the flow stress of a material to the strain rate, i.e. the strain rate sensitivity (m), governs the development of neck formation and therefore has a strong influence on the tensile ductility and hence formability of materials. Values of strain rate sensitivity range from unity, for the case of Newtonian viscous materials, to less than 0.1 for some dispersion strengthened alloys. Intermediate values of m = 0.5 are associated with classical superplastic materials which contain very fine grain sizes following specialized processing. An overview is given of the influence of strain rate sensitivity on tensile ductility and of the various materials groups that can exhibit high values of strain rate sensitivity. Recent examples of enhanced formability (or extended tensile ductility) in specific regimes between m = 1 and m = 0.3 are described, and potential areas for commercial exploitation are noted. These examples include: internal stress superplasticity, superplastic ceramics, superplastic intermetallics, superplastic laminated composites, superplastic behavior over six orders of magnitude of strain rate in a range of aluminum-based alloys and composites, and enhanced ductility in Al-Mg alloys that require no special processing for microstructural development.

  15. Advancing Materials Science using Neutrons at Oak Ridge National Laboratory

    ScienceCinema

    Carpenter, John

    2014-06-03

    Jack Carpenter, pioneer of accelerator-based pulsed spallation neutron sources, talks about neutron science at Oak Ridge National Laboratory (ORNL) and a need for a second target station at the Spallation Neutron Source (SNS). ORNL is the Department of Energy's largest multiprogram science and energy laboratory, and is home to two scientific user facilities serving the neutron science research community: the High Flux Isotope Reactor (HFIR) and SNS. HFIR and SNS provide researchers with unmatched capabilities for understanding the structure and properties of materials, macromolecular and biological systems, and the fundamental physics of the neutron. Neutrons provide a window through which to view materials at a microscopic level that allow researchers to develop better materials and better products. Neutrons enable us to understand materials we use in everyday life. Carpenter explains the need for another station to produce long wavelength neutrons, or cold neutrons, to answer questions that are addressed only with cold neutrons. The second target station is optimized for that purpose. Modern technology depends more and more upon intimate atomic knowledge of materials, and neutrons are an ideal probe.

  16. Advancing Materials Science using Neutrons at Oak Ridge National Laboratory

    SciTech Connect

    Carpenter, John

    2014-04-24

    Jack Carpenter, pioneer of accelerator-based pulsed spallation neutron sources, talks about neutron science at Oak Ridge National Laboratory (ORNL) and a need for a second target station at the Spallation Neutron Source (SNS). ORNL is the Department of Energy's largest multiprogram science and energy laboratory, and is home to two scientific user facilities serving the neutron science research community: the High Flux Isotope Reactor (HFIR) and SNS. HFIR and SNS provide researchers with unmatched capabilities for understanding the structure and properties of materials, macromolecular and biological systems, and the fundamental physics of the neutron. Neutrons provide a window through which to view materials at a microscopic level that allow researchers to develop better materials and better products. Neutrons enable us to understand materials we use in everyday life. Carpenter explains the need for another station to produce long wavelength neutrons, or cold neutrons, to answer questions that are addressed only with cold neutrons. The second target station is optimized for that purpose. Modern technology depends more and more upon intimate atomic knowledge of materials, and neutrons are an ideal probe.

  17. Novel Super-Elastic Materials for Advanced Bearing Applications

    NASA Technical Reports Server (NTRS)

    Dellacorte, Christopher

    2014-01-01

    Tribological surfaces of mechanical components encounter harsh conditions in terrestrial, marine and aerospace environments. Brinell denting, abrasive wear and fatigue often lead to life-limiting bearing and gear failures. Novel superelastic materials based upon Ni-Ti alloys are an emerging solution. Ni-Ti alloys are intermetallic materials that possess characteristics of both metals and ceramics. Ni-Ti alloys have intrinsically good aqueous corrosion resistance (they cannot rust), high hardness, relatively low elastic modulus, are chemically inert and readily lubricated. Ni-Ti alloys also belong to the family of superelastics and, despite high hardness, are able to withstand large strains without suffering permanent plastic deformation. In this paper, the use of hard, resilient Ni-Ti alloys for corrosion-proof, shockproof bearing and gear applications are presented. Through a series of bearing and gear development projects, it is demonstrated that Ni-Tis unique blend of materials properties lead to significantly improved load capacity, reduced weight and intrinsic corrosion resistance not found in any other bearing materials. Ni-Ti thus represents a new materials solution to demanding tribological applications.

  18. Development of Processing Techniques for Advanced Thermal Protection Materials

    NASA Technical Reports Server (NTRS)

    Selvaduray, Guna; Cox, Michael; Srinivasan, Vijayakumar

    1997-01-01

    Thermal Protection Materials Branch (TPMB) has been involved in various research programs to improve the properties and structural integrity of the existing aerospace high temperature materials. Specimens from various research programs were brought into the analytical laboratory for the purpose of obtaining and refining the material characterization. The analytical laboratory in TPMB has many different instruments which were utilized to determine the physical and chemical characteristics of materials. Some of the instruments that were utilized by the SJSU students are: Scanning Electron Microscopy (SEM), Energy Dispersive X-ray analysis (EDX), X-ray Diffraction Spectrometer (XRD), Fourier Transform-Infrared Spectroscopy (FTIR), Ultra Violet Spectroscopy/Visible Spectroscopy (UV/VIS), Particle Size Analyzer (PSA), and Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES). The above mentioned analytical instruments were utilized in the material characterization process of the specimens from research programs such as: aerogel ceramics (I) and (II), X-33 Blankets, ARC-Jet specimens, QUICFIX specimens and gas permeability of lightweight ceramic ablators. In addition to analytical instruments in the analytical laboratory at TPMB, there are several on-going experiments. One particular experiment allows the measurement of permeability of ceramic ablators. From these measurements, physical characteristics of the ceramic ablators can be derived.

  19. Advanced ceramic material for high temperature turbine tip seals

    NASA Technical Reports Server (NTRS)

    Solomon, N. G.; Vogan, J. W.

    1978-01-01

    Ceramic material systems are being considered for potential use as turbine blade tip gas path seals at temperatures up to 1370 1/4 C. Silicon carbide and silicon nitride structures were selected for study since an initial analysis of the problem gave these materials the greatest potential for development into a successful materials system. Segments of silicon nitride and silicon carbide materials over a range of densities, processed by various methods, a honeycomb structure of silicon nitride and ceramic blade tip inserts fabricated from both materials by hot pressing were tested singly and in combination. The evaluations included wear under simulated engine blade tip rub conditions, thermal stability, impact resistance, machinability, hot gas erosion and feasibility of fabrication into engine components. The silicon nitride honeycomb and low-density silicon carbide using a selected grain size distribution gave the most promising results as rub-tolerant shroud liners. Ceramic blade tip inserts made from hot-pressed silicon nitride gave excellent test results. Their behavior closely simulated metal tips. Wear was similar to that of metals but reduced by a factor of six.

  20. Advanced Process Technology: Combi Materials Science and Atmospheric Processing (Fact Sheet)

    SciTech Connect

    Not Available

    2011-06-01

    Capabilities fact sheet for the National Center for Photovoltaics: Process Technology and Advanced Concepts -- High-Throughput Combi Material Science and Atmospheric Processing that includes scope, core competencies and capabilities, and contact/web information.

  1. Materials issues for advanced electronic and optoelectronic connectors

    NASA Astrophysics Data System (ADS)

    Crane, J.; Wen, S.

    1990-09-01

    Trends of increased speed, density and power of electronic devices and circuitry translate to a need for connector substrate materials with improved form-ability and mechanical stability. Many contact surface requirements will continue to be met by precious metals for low contact force and tin in moderate contact force connectors. However, the demands for lower insertion forces, increased wear resistance, higher operating temperatures and improved corrosion resistance will challenge materials experts and connector designers to develop and utilize cost-effective replacements for tin and gold in electronic connectors. The stability and compatibility requirements of optoelectronic connectors provide challenges over a wide range of materials with the added dimension of accommodating essential optical characteristics.

  2. Development of processing techniques for advanced thermal protection materials

    NASA Technical Reports Server (NTRS)

    Selvaduray, Guna S.

    1995-01-01

    The main purpose of this work has been in the development and characterization of materials for high temperature applications. Thermal Protection Systems (TPS) are constantly being tested, and evaluated for increased thermal shock resistance, high temperature dimensional stability, and tolerance to environmental effects. Materials development was carried out through the use of many different instruments and methods, ranging from extensive elemental analysis to physical attributes testing. The six main focus areas include: (1) protective coatings for carbon/carbon composites; (2) TPS material characterization; (3) improved waterproofing for TPS; (4) modified ceramic insulation for bone implants; (5) improved durability ceramic insulation blankets; and (6) ultra-high temperature ceramics. This report describes the progress made in these research areas during this contract period.

  3. Advanced Strain-Isolation-Pad Material with Bonded Fibrous Construction

    NASA Technical Reports Server (NTRS)

    Seibold, R. W.; Saito, C. A.; Buller, B. W.

    1982-01-01

    The feasibility of utilizing air lay and liquid lay felt deposition techniques to fabricate strain isolation pad (SIP) materials for the Space Shuttle Orbiter was demonstrated. These materials were developed as candidate replacements for the present needled felt SIP used between the ceramic tiles and the aluminum skin on the undersurface of the Orbiter. The SIP materials that were developed consisted of high temperature aramid fibers deposited by controlled fluid (air or liquid) carriers to form low density unbonded felts. The deposited felts were then bonded at the fiber intersections with a small amount of high temperature polyimide resin. This type of bonded felt construction can potentially eliminate two of the problems associated with the present SIP, viz., transmittal of localized stresses into the tiles and load history dependent mechanical response. However, further work is needed to achieve adequate through thickness tensile strength in the bonded felts.

  4. Advanced materials development for multi-junction monolithic photovoltaic devices

    SciTech Connect

    Dawson, L.R.; Reno, J.L.

    1996-07-01

    We report results in three areas of research relevant to the fabrication of monolithic multi-junction photovoltaic devices. (1) The use of compliant intervening layers grown between highly mismatched materials, GaAs and GaP (same lattice constant as Si), is shown to increase the structural quality of the GaAs overgrowth. (2) The use of digital alloys applied to the MBE growth of GaAs{sub x}Sb{sub l-x} (a candidate material for a two junction solar cell) provides increased control of the alloy composition without degrading the optical properties. (3) A nitrogen plasma discharge is shown to be an excellent p-type doping source for CdTe and ZnTe, both of which are candidate materials for a two junction solar cell.

  5. Recent Advances and Developments in Composite Dental Restorative Materials

    PubMed Central

    Cramer, N.B.; Stansbury, J.W.; Bowman, C.N.

    2011-01-01

    Composite dental restorations represent a unique class of biomaterials with severe restrictions on biocompatibility, curing behavior, esthetics, and ultimate material properties. These materials are presently limited by shrinkage and polymerization-induced shrinkage stress, limited toughness, the presence of unreacted monomer that remains following the polymerization, and several other factors. Fortunately, these materials have been the focus of a great deal of research in recent years with the goal of improving restoration performance by changing the initiation system, monomers, and fillers and their coupling agents, and by developing novel polymerization strategies. Here, we review the general characteristics of the polymerization reaction and recent approaches that have been taken to improve composite restorative performance. PMID:20924063

  6. Nanostructured Materials for Advanced Electrochemical Energy Storage Applications

    NASA Astrophysics Data System (ADS)

    Wilson, Benjamin E.

    This dissertation discusses work aimed at developing and improving nanostructured materials for electrochemical energy storage, specifically electrochemical double layer capacitors (EDLCs) and lithium-ion batteries (LIBs). This was achieved through a combination of templating, precursor selection, and heteroatom doping to control the morphology and composition of the materials for improved performance in both types of energy storage. The first part of the thesis discusses EDLCs. First, a new method to produce soft-templated carbon materials is described. This process allows for improved production of mesoporous carbon made through soft templating. The work continues with using ionic liquids to dope nitrogen into hard templated mesoporous carbon. This led to a 40% improvement in specific capacitance due to improved conductivity. The section concludes with an investigation of physical and electrochemical properties of twelve ionic liquid electrolytes to determine which parameters are most important to achieve a high energy density. The second part discusses my work on LIBs, starting with a design of a low-cost electrochemical cell for in-situ X-ray diffraction monitoring during galvanostatic cycling. It continues with the development of a novel cathode material, Li8ZrO6, with a high lithium content. In this material, the redox activity is localized on oxygen atoms. Li8ZrO6 displays initial capacities higher than those of commercial materials but has large polarization. The capacity is further improved with transition metal doping, leading to a final specific capacity of over 175 mAh/g after 140 cycles at a rate of C/5.

  7. Fatigue Crack Growth Analysis Models for Functionally Graded Materials

    SciTech Connect

    Dag, Serkan; Yildirim, Bora; Sabuncuoglu, Baris

    2008-02-15

    The objective of this study is to develop crack growth analysis methods for functionally graded materials (FGMs) subjected to mode I cyclic loading. The study presents finite elements based computational procedures for both two and three dimensional problems to examine fatigue crack growth in functionally graded materials. Developed methods allow the computation of crack length and generation of crack front profile for a graded medium subjected to fluctuating stresses. The results presented for an elliptical crack embedded in a functionally graded medium, illustrate the competing effects of ellipse aspect ratio and material property gradation on the fatigue crack growth behavior.

  8. Advances in optical property measurements of spacecraft materials

    NASA Technical Reports Server (NTRS)

    Smith, Charles A.; Dever, Joyce A.; Jaworske, Donald A.

    1997-01-01

    Some of the instruments and experimental approaches, used for measuring the optical properties of thermal control systems, are presented. The instruments' use in studies concerning the effects of combined contaminants and space environment on these materials, and in the qualification of hardware for spacecraft, are described. Instruments for measuring the solar absorptance and infrared emittance offer improved speed, accuracy and data handling. A transient method for directly measuring material infrared emittance is described. It is shown that oxygen exposure before measuring the solar absorptance should be avoided.

  9. Advanced ceramic material for high temperature turbine tip seals

    NASA Technical Reports Server (NTRS)

    Vogan, J. W.; Solomon, N. G.; Stetson, A. R.

    1980-01-01

    Forty-one material systems were evaluated for potential use in turbine blade tip seal applications at 1370 C. Both ceramic blade tip inserts and abradable ceramic tip shoes were tested. Hot gas erosion, impact resistance, thermal stability, and dynamic rub performance were the criteria used in rating the various materials. Silicon carbide and silicon nitride were used, both as blade tips and abradables. The blade tip inserts were fabricated by hot pressing while low density and honeycomb abradables were sintered or reaction bonded.

  10. Advanced composites: Environmental effects on selected resin matrix materials

    NASA Technical Reports Server (NTRS)

    Welhart, E. K.

    1976-01-01

    The effects that expected space flight environment has upon the mechanical properties of epoxy and polyimide matrix composites were analyzed. Environmental phenomena covered water immersion, high temperature aging, humidity, lightning strike, galvanic action, electromagnetic interference, thermal shock, rain and sand erosion, and thermal/vacuum outgassing. The technology state-of-the-art for graphite and boron reinforced epoxy and polyimide matrix materials is summarized to determine the relative merit of using composites in the space shuttle program. Resin matrix composites generally are affected to some degree by natural environmental phenomena with polyimide resin matrix materials less affected than epoxies.

  11. Microgravity polymer and crystal growth at the Advanced Materials Center for the Commercial Development of Space

    NASA Technical Reports Server (NTRS)

    Mccauley, Lisa A.

    1990-01-01

    The microgravity research programs currently conducted by the Advanced Materials Center for the Commercial Development of Space (CCDS) are briefly reviewed. Polymer processing in space, which constitutes the most active microgravity program at the Advanced Materials CCDS, is conducted in three areas: membrane processing, multiphase composite behavior, and plasma polymerization. Current work in microgravity crystal growth is discussed with particular reference to the development of the Zeolite Crystal Growth facility.

  12. Advanced Structural and Functional Brain MRI in Multiple Sclerosis.

    PubMed

    Giorgio, Antonio; De Stefano, Nicola

    2016-04-01

    Conventional magnetic resonance imaging (MRI) of the central nervous system is crucial for an early and reliable diagnosis and monitoring of patients with multiple sclerosis (MS). Focal white matter (WM) lesions, as detected by MRI, are the pathological hallmark of the disease and show some relation to clinical disability, especially in the long run. Gray matter (GM) involvement is evident from disease onset and includes focal (i.e., cortical lesions) and diffuse pathology (i.e., atrophy). Both accumulate over time and show close relation to physical disability and cognitive impairment. Using advanced quantitative MRI techniques such as magnetization transfer imaging (MTI), diffusion tensor imaging (DTI), proton MR spectroscopy ((1)H-MRS), and iron imaging, subtle MS pathology has been demonstrated from early stages outside focal WM lesions in the form of widespread abnormalities of the normal appearing WM and GM. In addition, studies using functional MRI have demonstrated that brain plasticity is driven by MS pathology, playing adaptive or maladaptive roles to neurologic and cognitive status and explaining, at least in part, the clinicoradiological paradox of MS. PMID:27116723

  13. Material point method enhanced by modified gradient of shape function

    NASA Astrophysics Data System (ADS)

    Zhang, Duan Z.; Ma, Xia; Giguere, Paul T.

    2011-07-01

    A numerical scheme of computing quantities involving gradients of shape functions is introduced for the material point method (MPM), so that the quantities are continuous as material points move across cell boundaries. The noise and instability caused by cell crossing of the material points are then eliminated. In this scheme, the formulas used to compute these quantities can be expressed in the same forms as in the original material point method, but with the gradient of the shape function modified. For one-dimensional cases, the gradient of the shape function used in the generalized interpolation material point (GIMP) method is a special case of the modified gradient if the characteristic function of a material point is introduced. The characteristic function of a material point is not otherwise needed in this scheme, therefore difficulties in tracking its evolution are avoided. Although the support of the modified gradient of a shape function is enlarged from the cell containing the material point to also include the immediate neighbor cells, all the non-local effects of a material point can be accounted for by two consecutive local operations. Therefore this scheme can be used in calculations with unstructured grids. This scheme is proved to satisfy mass and momentum conservations exactly. The error in energy conservation is shown to be second order on both spatial and temporal discretizations. Although the error in energy conservation is the same order as that in the original material point method, numerical examples show that this scheme has significantly better energy conservation properties than those of the original material point method.

  14. Advanced nanostructured materials for energy storage and conversion

    NASA Astrophysics Data System (ADS)

    Hutchings, Gregory S.

    Due to a global effort to reduce greenhouse gas emissions and to utilize renewable sources of energy, much effort has been directed towards creating new alternatives to fossil fuels. Identifying novel materials for energy storage and conversion can enable radical changes to the current fuel production infrastructure and energy utilization. The use of engineered nanostructured materials in these systems unlocks unique catalytic activity in practical configurations. In this work, research efforts have been focused on the development of nanostructured materials to address the need for both better energy conversion and storage, with applications toward Li-O2 battery electrocatalysts, electrocatalytic generation of H2, conversion of furfural to useful chemicals and fuels, and Li battery anode materials. Highly-active alpha-MnO2 materials were synthesized for use as bifunctional oxygen reduction (ORR) and evolution (OER) catalysts in Li-O2 batteries, and were evaluated under operating conditions with a novel in situ X-ray absorption spectroscopy configuration. Through detailed analysis of local coordination and oxidation states of Mn atoms at key points in the electrochemical cycle, a self-switching behavior affecting the bifunctional activity was identified and found to be critical. In an additional study of materials for lithium batteries, nanostructured TiO2 anode materials doped with first-row transition metals were synthesized and evaluated for improving battery discharge capacity and rate performance, with Ni and Co doping at low levels found to cause the greatest enhancement. In addition to battery technology research, I have also sought to find inexpensive and earth-abundant electrocatalysts to replace state-of-the-art Pt/C in the hydrogen evolution reaction (HER), a systematic computational study of Cu-based bimetallic electrocatalysts was performed. During the screening of dilute surface alloys of Cu mixed with other first-row transition metals, materials with

  15. Application of advanced plasma technology to energy materials and environmental problems

    NASA Astrophysics Data System (ADS)

    Kobayashi, Akira

    2015-04-01

    Advanced plasma system has been proposed for various energy materials and for its application to environmental problems. The gas tunnel type plasma device developed by the author exhibits high energy density and also high efficiency. Regarding the application to thermal processing, one example is the plasma spraying of ceramics such as Al2O3 and ZrO2 as thermal barrier coatings (TBCs). The performances of these ceramic coatings are superior to conventional ones, namely, the properties such as the mechanical and chemical properties, thermal behavior and high temperature oxidation resistance of the alumina/zirconia thermal barrier coatings (TBCs) have been clarified and discussed. The ZrO2 composite coating has a possibility for the development of high functionally graded TBC. The results showed that the alumina/zirconia composite system exhibited an improvement of mechanical properties and oxidation resistance. Another application of gas tunnel type plasma to a functional material is the surface modification of metals. TiN films were formed in a short time of 5 s on Ti and its alloy. Also, thick TiN coatings were easily obtained by gas tunnel type plasma reactive spraying on any metals. Regarding the application to the environmental problems, the decomposition of CO2 gas is also introduced by applying the gas tunnel type plasma system.

  16. Advanced materials and techniques for fibre-optic sensing

    NASA Astrophysics Data System (ADS)

    Henderson, Philip J.

    2014-06-01

    Fibre-optic monitoring systems came of age in about 1999 upon the emergence of the world's first significant commercialising company - a spin-out from the UK's collaborative MAST project. By using embedded fibre-optic technology, the MAST project successfully measured transient strain within high-performance composite yacht masts. Since then, applications have extended from smart composites into civil engineering, energy, military, aerospace, medicine and other sectors. Fibre-optic sensors come in various forms, and may be subject to embedment, retrofitting, and remote interrogation. The unique challenges presented by each implementation require careful scrutiny before widespread adoption can take place. Accordingly, various aspects of design and reliability are discussed spanning a range of representative technologies that include resonant microsilicon structures, MEMS, Bragg gratings, advanced forms of spectroscopy, and modern trends in nanotechnology. Keywords: Fibre-optic sensors, fibre Bragg gratings, MEMS, MOEMS, nanotechnology, plasmon.

  17. Material selection for Multi-Function Waste Tank Facility tanks

    SciTech Connect

    Larrick, A.P.; Blackburn, L.D.; Brehm, W.F.; Carlos, W.C.; Hauptmann, J.P.; Danielson, M.J.; Westerman, R.E.; Divine, J.R.; Foster, G.M.

    1995-03-01

    This paper briefly summarizes the history of the materials selection for the US Department of Energy`s high-level waste carbon steel storage tanks. It also provides an evaluation of the materials for the construction of new tanks at the evaluation of the materials for the construction of new tanks at the Multi-Function Waste Tank Facility. The evaluation included a materials matrix that summarized the critical design, fabrication, construction, and corrosion resistance requirements: assessed. each requirement: and cataloged the advantages and disadvantages of each material. This evaluation is based on the mission of the Multi-Function Waste Tank Facility. On the basis of the compositions of the wastes stored in Hanford waste tanks, it is recommended that tanks for the Multi-Function Waste Tank Facility be constructed of ASME SA 515, Grade 70, carbon steel.

  18. Advances in materials and current collecting networks for AMTEC electrodes

    NASA Technical Reports Server (NTRS)

    Ryan, M. A.; Jeffries-Nakamura, B.; Williams, R. M.; Underwood, M. L.; O'Connor, D.; Kikkert, S.

    1992-01-01

    Electrode materials for the Alkali Metal Thermal to Electric Converter (AMTEC) play a significant role in the efficiency of the device. RhW and PtW alloys have been studied to determine the best performing material. While RhW electrodes typically have power densities somewhat lower than PtW electrodes, PtW performance is strongly influenced by the Pt/W ratio. The best performing Pt/W ratio is about 3.4. RhW electrodes sinter more slowly than PtW and are predicted to have operating lifetimes up to 40 years; PtW electrodes are predicted to have lifetimes up to 7 years. Interaction with the current collection network can significantly decrease lifetime by inducing metal migration and segregation and by accelerating the sintering rate.

  19. SRM nozzle design breakthroughs with advanced composite materials

    NASA Astrophysics Data System (ADS)

    Berdoyes, Michel

    1993-06-01

    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.

  20. Holographic femtosecond laser manipulation for advanced material processing

    NASA Astrophysics Data System (ADS)

    Hasegawa, Satoshi; Hayasaki, Yoshio

    2016-02-01

    Parallel femtosecond laser processing using a computer-generated hologram displayed on a spatial light modulator, known as holographic femtosecond laser processing, provides the advantages of high throughput and high-energy use efficiency. Therefore, it has been widely used in many applications, including laser material processing, two-photon polymerization, two-photon microscopy, and optical manipulation of biological cells. In this paper, we review the development of holographic femtosecond laser processing over the past few years from the perspective of wavefront and polarization modulation. In particular, line-shaped and vector-wave femtosecond laser processing are addressed. These beam-shaping techniques are useful for performing large-area machining in laser cutting, peeling, and grooving of materials and for high-speed fabrication of the complex nanostructures that are applied to material-surface texturing to control tribological properties, wettability, reflectance, and retardance. Furthermore, issues related to the nonuniformity of diffraction light intensity in optical reconstruction and wavelength dispersion from a computer-generated hologram are addressed. As a result, large-scale holographic femtosecond laser processing over 1000 diffraction spots was successfully demonstrated on a glass sample.

  1. Antimicrobial Materials for Advanced Microbial Control in Spacecraft Water Systems

    NASA Technical Reports Server (NTRS)

    Birmele, Michele; Caro, Janicce; Newsham, Gerard; Roberts, Michael; Morford, Megan; Wheeler, Ray

    2012-01-01

    Microbial detection, identification, and control are essential for the maintenance and preservation of spacecraft water systems. Requirements set by NASA put limitations on the energy, mass, materials, noise, cost, and crew time that can be devoted to microbial control. Efforts are being made to attain real-time detection and identification of microbial contamination in microgravity environments. Research for evaluating technologies for capability enhancement on-orbit is currently focused on the use of adenosine triphosphate (ATP) analysis for detection purposes and polymerase chain reaction (peR) for microbial identification. Additional research is being conducted on how to control for microbial contamination on a continual basis. Existing microbial control methods in spacecraft utilize iodine or ionic silver biocides, physical disinfection, and point-of-use sterilization filters. Although these methods are effective, they require re-dosing due to loss of efficacy, have low human toxicity thresholds, produce poor taste, and consume valuable mass and crew time. Thus, alternative methods for microbial control are needed. This project also explores ultraviolet light-emitting diodes (UV-LEDs), surface passivation methods for maintaining residual biocide levels, and several antimicrobial materials aimed at improving current microbial control techniques, as well as addressing other materials presently under analysis and future directions to be pursued.

  2. Advances in Materials Research: An Internship at Kennedy Space Center

    NASA Technical Reports Server (NTRS)

    Barrios, Elizabeth A.; Roberson, Luke B.

    2011-01-01

    My time at Kennedy Space Center. was spent immersing myself in research performed in the Materials Science Division of the Engineering Directorate. My Chemical Engineering background provided me the ability to assist in many different projects ranging from tensile testing of composite materials to making tape via an extrusion process. However, I spent the majority of my time on the following three projects: (1) testing three different materials to determine antimicrobial properties; (2) fabricating and analyzing hydrogen sensing tapes that were placed at the launch pad for STS-133 launch; and (3) researching molten regolith electrolysis at KSC to prepare me for my summer internship at MSFC on a closely related topic. This paper aims to explain, in detail, what I have learned about these three main projects. It will explain why this research is happening and what we are currently doing to resolve the issues. This paper will also explain how the hard work and experiences that I have gained as an intern have provided me with the next big step towards my career at NASA.

  3. Gravitational Effects on Combustion Synthesis of Advanced Porous Materials

    NASA Technical Reports Server (NTRS)

    Zhang, X.; Moore, J. J.; Schowengerdt, F. D.; Thorne, K.

    2000-01-01

    Combustion Synthesis (self-Propagating high-temperature synthesis-(SHS)) of porous Ti-TiB(x), composite materials has been studied with respect to the sensitivity to the SHS reaction parameters of stoichiometry, green density, gasifying agents, ambient pressure, diluents and gravity. The main objective of this research program is to engineer the required porosity and mechanical properties into the composite materials to meet the requirements of a consumer, such as for the application of bone replacement materials. Gravity serves to restrict the gas expansion and the liquid movement during SHS reaction. As a result, gravitational forces affect the microstructure and properties of the SHS products. Reacting these SHS systems in low gravity in the KC-135 aircraft has extended the ability to form porous products. This paper will emphasize the effects of gravity (low g, 1g and 2g) on the SHS reaction process, and the microstructure and properties of the porous composite. Some of biomedical results are also discussed.

  4. Advanced materials development for fossil energy conversion applications

    SciTech Connect

    Bates, J.L.; Chick, L.A.; Kingsley, J.J.; Pederson, L.R.; Weber, W.J.; Youngblood, G.E.; Hurst, J.K.; Bell, A.E.; Grainger, D.W.; Rananavare, S.B.; Roe, D.K.; Thompson, D.H.

    1992-05-01

    Research activities being conducted as part of this project include: (1) fundamental studies of electrochemical processes occurring at surfaces and interfaces in fuel cells, and (2) development of novel materials synthesis and processing methodologies for fossil energy conversion applications. Complex impedance and dc polarization studies of the electrocatalytic activity at the cathode have allowed intrinsic materials properties to be separated from extrinsic properties related to morphology. Mixed conduction in cathode materials was shown to dramatically enhance electrocatalytic activity with this approach. Combustion synthesis methods were used to prepare multicomponent perovskite catalysts in the La{sub 1-x}Sr{sub x}Co{sub 1-y}Fe{sub y}O{sub 3} system. Electronic properties of these catalysts can be altered by adjusting the composition, which affects both catalytic activity and selectivity. Inverse micelles have been utilized to prepare nanosized nickel sulfide particles, which show promise as hydrodesulfurization catalysts for liquefied coal. Self-assembling organic monolayers and derivatized inorganic surfaces have been used to control nucleation and crystal morphology of inorganic phases.

  5. Task 2: Materials for Advanced Boiler and Oxy-combustion Systems

    SciTech Connect

    Holcolm, Gordon R.; McGhee, Barry

    2009-05-01

    The PowerPoint presentation provides an overview of the tasks for the project: Characterize advanced boiler (oxy-fuel combustion, biomass co-fired) gas compositions and ash deposits; Generate critical data on the effects of environmental conditions; develop a unified test method with a view to future standardization; Generate critical data for coating systems for use in advanced boiler systems; Generate critical data for flue gas recycle piping materials for oxy-fuel systems; and, Compile materials performance data from laboratory and pilot plant exposures of candidate alloys for use in advanced boiler systems.

  6. Programmable gradational micropatterning of functional materials using maskless lithography controlling absorption.

    PubMed

    Jung, Yushin; Lee, Howon; Park, Tae-Joon; Kim, Sungsik; Kwon, Sunghoon

    2015-01-01

    The demand for patterning functional materials precisely on surfaces of stimuli-responsive devices has increased in many research fields. In situ polymerization technology is one of the most convenient ways to place the functional materials on a desired location with micron-scale accuracy. To fabricate stimuli-responsive surfaces, controlling concentration of the functional material is much as important as micropatterning them. However, patterning and controlling concentration of the functional materials simultaneously requires an additional process, such as preparing multiple co-flow microfluidic structures and numbers of solutions with various concentrations. Despite applying these processes, fabricating heterogeneous patterns in large scale (millimeter scale) is still impossible. In this study, we propose an advanced in situ polymerization technique to pattern the surface in micron scale in a concentration-controlled manner. Because the concentration of the functional materials is manipulated by self-assembly on the surface, a complex pattern could be easily fabricated without any additional procedure. The complex pattern is pre-designed with absorption amount of the functional material, which is pre-determined by the duration of UV exposure. We show that the resolution reaches up to 2.5 μm and demonstrate mm-scale objects, maintaining the same resolution. We also fabricated Multi-bit barcoded micro particles verify the flexibility of our system. PMID:26490360

  7. Programmable gradational micropatterning of functional materials using maskless lithography controlling absorption

    NASA Astrophysics Data System (ADS)

    Jung, Yushin; Lee, Howon; Park, Tae-Joon; Kim, Sungsik; Kwon, Sunghoon

    2015-10-01

    The demand for patterning functional materials precisely on surfaces of stimuli-responsive devices has increased in many research fields. In situ polymerization technology is one of the most convenient ways to place the functional materials on a desired location with micron-scale accuracy. To fabricate stimuli-responsive surfaces, controlling concentration of the functional material is much as important as micropatterning them. However, patterning and controlling concentration of the functional materials simultaneously requires an additional process, such as preparing multiple co-flow microfluidic structures and numbers of solutions with various concentrations. Despite applying these processes, fabricating heterogeneous patterns in large scale (millimeter scale) is still impossible. In this study, we propose an advanced in situ polymerization technique to pattern the surface in micron scale in a concentration-controlled manner. Because the concentration of the functional materials is manipulated by self-assembly on the surface, a complex pattern could be easily fabricated without any additional procedure. The complex pattern is pre-designed with absorption amount of the functional material, which is pre-determined by the duration of UV exposure. We show that the resolution reaches up to 2.5 μm and demonstrate mm-scale objects, maintaining the same resolution. We also fabricated Multi-bit barcoded micro particles verify the flexibility of our system.

  8. Programmable gradational micropatterning of functional materials using maskless lithography controlling absorption

    PubMed Central

    Jung, Yushin; Lee, Howon; Park, Tae-Joon; Kim, Sungsik; Kwon, Sunghoon

    2015-01-01

    The demand for patterning functional materials precisely on surfaces of stimuli-responsive devices has increased in many research fields. In situ polymerization technology is one of the most convenient ways to place the functional materials on a desired location with micron-scale accuracy. To fabricate stimuli-responsive surfaces, controlling concentration of the functional material is much as important as micropatterning them. However, patterning and controlling concentration of the functional materials simultaneously requires an additional process, such as preparing multiple co-flow microfluidic structures and numbers of solutions with various concentrations. Despite applying these processes, fabricating heterogeneous patterns in large scale (millimeter scale) is still impossible. In this study, we propose an advanced in situ polymerization technique to pattern the surface in micron scale in a concentration-controlled manner. Because the concentration of the functional materials is manipulated by self-assembly on the surface, a complex pattern could be easily fabricated without any additional procedure. The complex pattern is pre-designed with absorption amount of the functional material, which is pre-determined by the duration of UV exposure. We show that the resolution reaches up to 2.5 μm and demonstrate mm-scale objects, maintaining the same resolution. We also fabricated Multi-bit barcoded micro particles verify the flexibility of our system. PMID:26490360

  9. Melt infiltration: an emerging technique for the preparation of novel functional nanostructured materials.

    PubMed

    de Jongh, Petra E; Eggenhuisen, Tamara M

    2013-12-10

    The rapidly expanding toolbox for design and preparation is a major driving force for the advances in nanomaterials science and technology. Melt infiltration originates from the field of ceramic nanomaterials and is based on the infiltration of porous matrices with the melt of an active phase or precursor. In recent years, it has become a technique for the preparation of advanced materials: nanocomposites, pore-confined nanoparticles, ordered mesoporous and nanostructured materials. Although certain restrictions apply, mostly related to the melting behavior of the infiltrate and its interaction with the matrix, this review illustrates that it is applicable to a wide range of materials, including metals, polymers, ceramics, and metal hydrides and oxides. Melt infiltration provides an alternative to classical gas-phase and solution-based preparation methods, facilitating in several cases extended control over the nanostructure of the materials. This review starts with a concise discussion on the physical and chemical principles for melt infiltration, and the practical aspects. In the second part of this contribution, specific examples are discussed of nanostructured functional materials with applications in energy storage and conversion, catalysis, and as optical and structural materials and emerging materials with interesting new physical and chemical properties. Melt infiltration is a useful preparation route for material scientists from different fields, and we hope this review may inspire the search and discovery of novel nanostructured materials. PMID:24014262

  10. PREFACE: 3rd International Symposium on Functional Materials 2009 (ISFM 2009) 3rd International Symposium on Functional Materials 2009 (ISFM 2009)

    NASA Astrophysics Data System (ADS)

    Kiwon, Kim; Li, Lu; Taehyun, Nam; Jouhyeon, Ahn

    2010-05-01

    The 3rd International Symposium on Functional Materials 2009 (ISFM 2009) and its preconference, Advances in Functional Materials 2009 (AFM 2009), were successfully held in the Republic of Korea from 15-18 June 2009 and in the People's Republic of China from 8-12 June 2009, respectively. The two conferences attracted over 300 oral and poster presentations from over 12 countries including Australia, Canada, China, Germany, Japan, India, Israel, Korea, The Netherlands, Thailand, the UK and the USA. In the two conferences, eight keynote lectures were delivered by S Miyazaki, S A Akbar, D J Singh, C Suryanarayana, M~Greenblatt, H Zhang, T Sato and J Ding. This topical issue of Physica Scripta contains papers presented at the ISFM 2009 and AFM 2009. Keyan Li from Dalian University, People's Republic of China, presents some empirical formulae to estimate the elastic moduli of rocksalt-, zincblende- and chalcopyrite-structured crystals, on the basis of electronegativities of bonded atoms in the crystallographic frame. Min-Jung Kim from Hanyang University, Korea, reports on the preparation and characterization of carboxyl functionalization of magnetite nanoparticles for oligonucleotide immobilization. F Yan from the National University of Singapore studies the fabrication of Bi(Fe0.5Sc0.5)O3-PbTiO3 (BSF-PT) thin films by pulsed laser deposition, and the enhanced magnetic moment with respect to BiFeO3-PbTiO3. Dong-Gil Lee from Pusan National University, Korea, reports on the sterilization of enteropathogenic Escherichia coli using nanofiber TiO2 films prepared by the electrostatic spray method. Sang-Eun Park from the Korea Institute of Science and Technology reports on the study of encapsulated Fe3O4 nanoparticles with a silica thin layer with a reversible capacity of about 363 mAhg-1. Other researchers report on many other exiting achievements in the fields of ferromagnetic materials, magneto-optical materials, thermoelectric materials, shape memory materials, fuel-cell and

  11. Advanced materials for next generation NiMH portable, HEV and EV batteries

    SciTech Connect

    Ovshinsky, S.R.; Dhar, S.K.; Fetcenko, M.A.; Corrigan, D.A.; Reichman, B.; Young, K.; Fierro, C.; Venkatesan, S.; Gifford, P.; Koch, J.

    1998-07-01

    While Ovonic NiMH batteries are already in high volume commercial production for portable applications, advances in materials technology have enabled performance improvements in specific energy (100 Wh/kg), specific power (600-1000 W/kg), high temperature operation, charge retention, and voltage stability. Concurrent with technology advances, Ovonic NiMH batteries have established performance and commercial milestones in electric vehicles, hybrid electric vehicles, as well as scooter, motorcycle and bicycle applications. As important as these advances, significant manufacturing cost reductions have also occurred which allow continued growth of NiMH technology. In this paper, advances in performance, applications and cost reduction are discussed with particular emphasis on the improved proprietary metal hydride and nickel hydroxide materials that make such advances possible.

  12. Production of modern functional materials based on renewable vegetable resources

    NASA Astrophysics Data System (ADS)

    Onishchenko, D. V.; Reva, V. P.

    2013-05-01

    An energy-saving technology for production of variously structured carbon modifications from a renewable vegetable raw material, i.e., the waste of agricultural crops and peat moss, has been developed. Promising functional materials — refractory compounds (tungsten and titanium carbides) and oil sorbents possessing a combination of high operating characteristics — have been formed on the basis of the synthesized carbon modifications.

  13. Surface Intensive Materials Processing for Multi-Functional Purposes

    SciTech Connect

    Ila, D.; Williams, E.K.; Muntele, C.I.; George, M.A.; Poker, D.B.; Hensley, D.K.; Larkin, D.J.

    2000-03-06

    We have chosen silicon carbide (SiC) as a multi-functional material to demonstrate the application of surface intensive processing for device fabrication. We will highlight two devices which are produced in house at the Center for Irradiation of materials of Alabama A and M university: (A) High temperature electronic gas sensor, (B) High temperature optical properties/sensor.

  14. EDITORIAL: Van der Waals interactions in advanced materials, in memory of David C Langreth Van der Waals interactions in advanced materials, in memory of David C Langreth

    NASA Astrophysics Data System (ADS)

    Hyldgaard, Per; Rahman, Talat S.

    2012-10-01

    rationale for considering a more general switch to nonlocal functionals. Graziano et al note that the accuracy in the description of some soft layered systems like graphene and boron-nitride can be increased by changing the exchange description away from what was suggested in the original vdW-DF method. Hanke et al focused on the weak chemisorption of ethene on the various Cu facets that have an increasing degree of openness and provide a method for benchmarking through comparison with experimental observations. Finally, Björkman et al raise the question 'Are we van der Waals ready?' and proceed to test our readiness by benchmarking the performance of a range of vdW-aware methods for the group of 96 known layered structures. We have also included in this special issue one study of nonequilibrium transport which is linked to David's work in formal scattering theory [1, 2] and which observes that vdW forces (and possible generalizations to nonequilibrium transport conditions) will be of central importance in a richer computational characterization of molecular electronics under operational conditions. David was always keen to spearhead the development of tools that improved descriptions of nature and addressed actual experiments. We know that he was happy that DMP started the focused session on vdW and materials in 2011. We know that he would have thoroughly appreciated the articles in this special issue. He would have hoped, as we do, that materials theory may continue to learn how to tackle even more exciting experimental problems and that we may continue to deepen our understanding of materials and their functionality. Bibliography [1]Langreth D C 1976 1975 Nato Advanced Study Institute on Linear and Nonlinear Transport in Solids, Antwerben vol B17 (New York: Plenum) pp 3-32 [2]Langreth D C 1966 Friedel sum rule for Anderson's model of localized impurity states Phys. Rev. 150 516 [3]Langreth D C and Perdew J P 1975 The exchange-correlation energy of a metallic surface

  15. Materials and structural aspects of advanced gas-turbine helicopter engines

    NASA Technical Reports Server (NTRS)

    Freche, J. C.; Acurio, J.

    1979-01-01

    The key to improved helicopter gas turbine engine performance lies in the development of advanced materials and advanced structural and design concepts. The modification of the low temperature components of helicopter engines (such as the inlet particle separator), the introduction of composites for use in the engine front frame, the development of advanced materials with increased use-temperature capability for the engine hot section, can result in improved performance and/or decreased engine maintenance cost. A major emphasis in helicopter engine design is the ability to design to meet a required lifetime. This, in turn, requires that the interrelated aspects of higher operating temperatures and pressures, cooling concepts, and environmental protection schemes be integrated into component design. The major material advances, coatings, and design life-prediction techniques pertinent to helicopter engines are reviewed; the current state-of-the-art is identified; and when appropriate, progress, problems, and future directions are assessed.

  16. Advances in materials for room temperature hydrogen sensors.

    PubMed

    Arya, Sunil K; Krishnan, Subramanian; Silva, Hayde; Jean, Sheila; Bhansali, Shekhar

    2012-06-21

    Hydrogen (H(2)), as a source of energy, continues to be a compelling choice in applications ranging from fuel cells and propulsion systems to feedstock for chemical, metallurgical and other industrial processes. H(2), being a clean, reliable, and affordable source, is finding ever increasing use in distributed electric power generation and H(2) fuelled cars. Although still under 0.1%, the distributed use of H(2) is the fastest growing area. In distributed H(2) storage, distribution, and consumption, safety continues to be a critical aspect. Affordable safety systems for distributed H(2) applications are critical for the H(2) economy to take hold. Advances in H(2) sensors are driven by specificity, reliability, repeatability, stability, cost, size, response time, recovery time, operating temperature, humidity range, and power consumption. Ambient temperature sensors for H(2) detection are increasingly being explored as they offer specificity, stability and robustness of high temperature sensors with lower operational costs and significantly longer operational lifetimes. This review summarizes and highlights recent developments in room temperature H(2) sensors. PMID:22582176

  17. Recent advances in the mechanical durability of superhydrophobic materials.

    PubMed

    Milionis, Athanasios; Loth, Eric; Bayer, Ilker S

    2016-03-01

    Large majority of superhydrophobic surfaces have very limited mechanical wear robustness and long-term durability. This problem has restricted their utilization in commercial or industrial applications and resulted in extensive research efforts on improving resistance against various types of wear damage. In this review, advances and developments since 2011 in this field will be covered. As such, we summarize progress on fabrication, design and understanding of mechanically durable superhydrophobic surfaces. This includes an overview of recently published diagnostic techniques for probing and demonstrating tribo-mechanical durability against wear and abrasion as well as other effects such as solid/liquid spray or jet impact and underwater resistance. The review is organized in terms of various types of mechanical wear ranging from substrate adhesion, tangential surface abrasion, and dynamic impact to ultrasonic processing underwater. In each of these categories, we highlight the most successful approaches to produce robust surfaces that can maintain their non-wetting state after the wear or abrasive action. Finally, various recommendations for improvement of mechanical wear durability and its quantitative evaluation are discussed along with potential future directions towards more systematic testing methods which will also be acceptable for industry. PMID:26792021

  18. Temperature controlled material irradiation in the advanced test reactor

    SciTech Connect

    Furstenau, R.V.; Ingrahm, F.W.

    1995-12-31

    The Advanced Test Reactor (ATR) is located at the Idaho National Engineering Laboratory (INEL) near Idaho Falls, Idaho, USA and is owned and regulated by the U.S. Department of Energy (US DOE). The ATR is operated for the US DOE by Lockheed Martin Idaho Technologies. In recent years, prime irradiation space in the ATR has been made available for use by customers having irradiation service needs in addition to the reactor`s principal user, the U.S. Naval Nuclear Propulsion Program. To enhance the reactor`s capabilities, the US DOE has initiated the development of an Irradiation Test Vehicle (ITV) capable of providing neutron spectral tailoring and temperature control for up to 28 experiments. The ATR-ITV will have the flexibility to simultaneously support a variety of experiments requiring fast, thermal or mixed spectrum neutron environments. Temperature control is accomplished by varying the thermal conductivity across a gas gap established between the experiment specimen capsule wall and the experiment `in-pile tube (IPT)` inside diameter. Thermal conductivity is adjusted by alternating the control gas mixture ratio of two gases with different thermal conductivities.

  19. Nonlinear mechanical behavior of thermoplastic matrix materials for advanced composites

    NASA Technical Reports Server (NTRS)

    Arenz, R. J.; Landel, R. F.

    1989-01-01

    Two recent theories of nonlinear mechanical response are quantitatively compared and related to experimental data. Computer techniques are formulated to handle the numerical integration and iterative procedures needed to solve the associated sets of coupled nonlinear differential equations. Problems encountered during these formulations are discussed and some open questions described. Bearing in mind these cautions, the consequences of changing parameters that appear in the formulations on the resulting engineering properties are discussed. Hence, engineering approaches to the analysis of thermoplastic matrix material can be suggested.

  20. Statistical Methods Handbook for Advanced Gas Reactor Fuel Materials

    SciTech Connect

    J. J. Einerson

    2005-05-01

    Fuel materials such as kernels, coated particles, and compacts are being manufactured for experiments simulating service in the next generation of high temperature gas reactors. These must meet predefined acceptance specifications. Many tests are performed for quality assurance, and many of these correspond to criteria that must be met with specified confidence, based on random samples. This report describes the statistical methods to be used. The properties of the tests are discussed, including the risk of false acceptance, the risk of false rejection, and the assumption of normality. Methods for calculating sample sizes are also described.

  1. Graphene covered SiC powder as advanced photocatalytic material

    NASA Astrophysics Data System (ADS)

    Zhu, Kaixing; Guo, Liwei; Lin, Jingjing; Hao, Weichang; Shang, Jun; Jia, Yuping; Chen, Lianlian; Jin, Shifeng; Wang, Wenjun; Chen, Xiaolong

    2012-01-01

    Graphene covered SiC powder (GCSP) has been fabricated by well established method of high temperature thermal decomposition of SiC. The structural and photocatalystic characteristics of the prepared GCSP were investigated and compared with that of the pristine SiC powder. Under UV illumination, more than 100% enhancement in photocatalystic activity is achieved in degradation of Rhodamine B (Rh B) by GCSP catalyst than by pristine SiC powder. The possible mechanisms underlining the observed results are discussed. The results suggested that GCSP as a composite of graphene based material has great potential for use as a high performance photocatalyst.

  2. Advanced materials and fabrication processes for supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    Guess, M. K.; Kaneko, R. S.; Wald, G. G.

    1981-01-01

    Research and development programs to develop high-strength aluminum alloys and low-cost materials and fabrication techniques for titanium alloys are being conducted. Thirteen aluminum alloy compositions are being evaluated. A section of a production component was fabricated using superplastic forming and diffusion bonding (SPF/DB) and fabrication studies are being conducted on three low temperature forming beta titanium alloys. Cost studies indicate substantial structural cost reduction potentials resulting from the use of both aluminum alloys and low-cost titanium fabrication techniques. Lowest overall costs are indicated for a composite/aluminum or composite titanium structure.

  3. Advanced Porous Coating for Low-Density Ceramic Insulation Materials

    NASA Technical Reports Server (NTRS)

    Leiser, Daniel B.; Churchward, Rex; Katvala, Victor; Stewart, David; Balter, Aliza

    1988-01-01

    The need for improved coatings on low-density reusable surface insulation (RSI) materials used on the space shuttle has stimulated research into developing tougher coatings. The processing of a new porous composite "coating" for RST called toughened unipiece fibrous insulation Is discussed. Characteristics including performance in a simulated high-speed atmospheric entry, morphological structure before and after this exposure, resistance to Impact, and thermal response to a typical heat pulse are described. It is shown that this coating has improved impact resistance while maintaining optical and thermal properties comparable to the previously available reaction-cured glass coating.

  4. Advanced Lithium Ion Battery Materials Prepared with Atomic Layer Deposition

    NASA Astrophysics Data System (ADS)

    Cavanagh, Andrew S.

    As the world consumes the dwindling supply of fossil fuels, an alternative to gasoline powered vehicles will become necessary. Lithium ion batteries (LIBs) are emerging as the dominant power source for portable electronics, and are seen as a promising energy source in the development of electric vehicles. Current LIB technology is not well suited for vehicles, increases in the energy density, power density and durability are needed before LIB are ready for widespread use in electric vehicles. LiCoO2 and graphite are the dominant cathode and anode active materials, respectively in LIBs. On the cathode side, instabilities in LiCoO 2 can lead to the deterioration of the LIB. Decomposition of electrolyte on the graphite anode surface to form a solid-electrolyte interphase (SEI) consumes lithium from the cathode resulting in a lower battery capacity. Instabilities in the in the SEI can result in catastrophic battery failure. Previous studies have employed metal oxides films, typically grown with wet chemical techniques, to stabilize LiCoO2 and mitigate the formation of the SEI on graphite. The thicknesses of films grown with wet chemical techniques was typically ˜50--1000 A. In order to achieve higher power densities, the particle size of LIB active materials is being scaled down. As active materials get smaller the mass contribution of a protective film can become a significant fraction of the total mass. Atomic layer deposition (ALD) has been used to grow ultra thin films of Al2O3 on LiCoO2 and graphite. By altering the interaction between the active material and the battery electrolyte it was possible to improve the stability of both LiCoO2 and graphite electrodes in LIBs. In the case of graphite, the Al2O3 film may be thought of as an artificial SEI. During the initial charge-discharge cycle of a LIB, the electrolyte decomposes on the anode to form the SEI. The formation of the SEI is believed to prevent further decomposition of the electrolyte on the anode surface

  5. Recent advances in auxiliary-field methods --- simulations in lattice models and real materials

    NASA Astrophysics Data System (ADS)

    Zhang, Shiwei

    2007-03-01

    We have developed an auxiliary-field (AF) quantum Monte Carlo (QMC) method for many-body simulations. The method takes the form of a linear superposition of independent-particle calculations in fluctuating external fields. ``Entanglement'' of the different field configurations leads to random walks in Slater determinant space. We formulate an approximate constraint on the random walk paths to control the sign/phase problem, which has shown to be very accurate even with simple mean-field solutions as the constraining trial wave function. The same method can be applied to both simplified lattice models and real materials. For realistic electronic Hamiltonians, each random walk stream resembles a density-functional theory (DFT) calculation in random local fields. Thus, the AF QMC method can directly import existing technology from standard electronic structure methods into a many-body QMC framework. We have demonstrated this method with calculations in close to 100 systems, including Si solid, first- and second-row molecular systems, molecules of heavier post-d elements, transition-metal systems, and ultra-cold atomic gases. In these we have operated largely in an automated mode, inputting the DFT or Hartree-Fock solutions as trial wave functions. The AF QMC results showed consistently good agreement with near-exact quantum chemistry results and/or experiment. I will also discuss additional algorithmic advances which can further improve the method in strongly correlated systems. Supported by ARO, NSF, ONR, and DOE-cmsn.

  6. Advanced methods for preparation and characterization of infrared detector materials

    NASA Technical Reports Server (NTRS)

    Broerman, J. G.; Morris, B. J.; Meschter, P. J.

    1983-01-01

    Crystals were prepared by the Bridgman-Stockbarger method with a wide range of crystal growth rates and temperature gradients adequate to prevent constitutional supercooling under diffusion-limited, steady-state, growth conditions. The longitudinal compositional gradients for different growth conditions and alloy compositions were calculated and compared with experimental data to develop a quantitative model of solute redistribution during the crystal growth of the alloys. Measurements were performed to ascertain the effect of growth conditions on radial compositional gradients. The pseudobinary HgTe-CdTe constitutional phase diagram was determined by precision differential-thermal-analysis measurements and used to calculate the segregation coefficient of Cd as a function of x and interface temperature. Experiments were conducted to determine the ternary phase equilibria in selected regions of the Hg-Cd-Te constitutional phase diagram. Electron and hole mobilities as functions of temperature were analyzed to establish charge-carrier scattering probabilities. Computer algorithms specific to Hg(1-x)CdxTe were developed for calculations of the charge-carrier concentration, charge-carrier mobilities, Hall coefficient, and Dermi Fermi energy as functions of x, temperature, ionized donor and acceptor concentrations, and neutral defect concentrations.

  7. Application of advanced material systems to composite frame elements

    NASA Technical Reports Server (NTRS)

    Llorente, Steven; Minguet, Pierre; Fay, Russell; Medwin, Steven

    1992-01-01

    A three phase program has been conducted to investigate DuPont's Long Discontinuous Fiber (LDF) composites. Additional tests were conducted to compare LDF composites against toughened thermosets and a baseline thermoset system. Results have shown that the LDF AS4/PEKK offers improved interlaminar (flange bending) strength with little reduction in mechanical properties due to the discontinuous nature of the fibers. In the third phase, a series of AS4/PEKK LDF C-section curved frames (representing a typical rotorcraft light frame) were designed, manufactured and tested. Specimen reconsolidation after 'stretch forming' and frame thickness were found to be key factors in this light frame's performance. A finite element model was constructed to correlate frame test results with expected strain levels determined from material property tests. Adequately reconsolidated frames performed well and failed at strain levels at or above baseline thermoset material test strains. Finally a cost study was conducted which has shown that the use of LDF for this frame would result in a significant cost savings, for moderate to large lot sizes compared with the hand lay-up of a thermoset frame.

  8. Impact of functional mandibular advancement appliances on the temporomandibular joint - a systematic review

    PubMed Central

    Ivorra-Carbonell, Laura; Montiel-Company, José-María; Almerich-Silla, José-Manuel; Paredes-Gallardo, Vanessa

    2016-01-01

    Background Although many orthodontists have no doubts about the effectiveness of functional appliances for mandibular advancement, the impact on the temporomandibular joint (TMJ) is still in dispute. The objective of this systematic review is to examine the main effects on the TMJ of using functional appliances, both in healthy patients and in patients with a pre-existing disorder. Material and Methods A systematic review of the literature was conducted in accordance with the PRISMA guidelines. Only systematic reviews, meta-analyses, randomized clinical trials (RCTs), case-control studies and cohort studies were included. A detailed language-independent electronic search was conducted in the Pubmed, Scopus, Cochrane Library and Embase databases. All studies published between 2000 and 2015 were included. Results A total of 401 articles were identified. Of these, 159 were duplicates and were excluded. On reading the title and abstract, 213 articles were excluded because they did not answer the research question, leaving a total of 29 articles. These articles were read and assessed. Following critical reading of the full text, eight articles were excluded: seven because they were considered of low quality and one because it published redundant data. As a result, 21 articles were included. Conclusions After treatment with functional appliances, the condyle was found to be in a more advanced position, with remodelling of the condyle and adaptation of the morphology of the glenoid fossa. No significant adverse effects on the TMJ were observed in healthy patients and the appliances could improve joints that initially presented forward dislocation of the disk. Key words:Temporomandibular joint, TMJ, orthodontic appliances, functional, mandibular advancement, herbst appliance, bionator. PMID:27475694

  9. Macroscopic analysis of axisymmetric functionally gradient material under thermal loading

    SciTech Connect

    Kwon, P.; Dharan, C.K.H.; Ferrari, M. )

    1994-06-01

    The axisymmetric functionally gradient materials (FGMs) subject to nonuniform temperature variations were studied with the combined use of homogenization and inhomogeneous eigenstrained media analysis. The material properties and the temperature variations were assumed to depend on the radial coordinate only. The inhomogeneous material properties of the FGM cylinder can be obtained by modulating the concentration level of spherical alumina particles in an aluminum matrix. The resulting stresses due to the temperature variation are presented for numerous distribution functions of alumina particles. It is shown that the particle distribution extensively influences the intensity and profile of the thermal stresses.

  10. Lightweighting Automotive Materials for Increased Fuel Efficiency and Delivering Advanced Modeling and Simulation Capabilities to U.S. Manufacturers

    SciTech Connect

    Hale, Steve

    2013-09-11

    Abstract The National Center for Manufacturing Sciences (NCMS) worked with the U.S. Department of Energy (DOE), National Energy Technology Laboratory (NETL), to bring together research and development (R&D) collaborations to develop and accelerate the knowledgebase and infrastructure for lightweighting materials and manufacturing processes for their use in structural and applications in the automotive sector. The purpose/importance of this DOE program: • 2016 CAFÉ standards. • Automotive industry technology that shall adopt the insertion of lightweighting material concepts towards manufacturing of production vehicles. • Development and manufacture of advanced research tools for modeling and simulation (M&S) applications to reduce manufacturing and material costs. • U.S. competitiveness that will help drive the development and manufacture of the next generation of materials. NCMS established a focused portfolio of applied R&D projects utilizing lightweighting materials for manufacture into automotive structures and components. Areas that were targeted in this program: • Functionality of new lightweighting materials to meet present safety requirements. • Manufacturability using new lightweighting materials. • Cost reduction for the development and use of new lightweighting materials. The automotive industry’s future continuously evolves through innovation, and lightweight materials are key in achieving a new era of lighter, more efficient vehicles. Lightweight materials are among the technical advances needed to achieve fuel/energy efficiency and reduce carbon dioxide (CO2) emissions: • Establish design criteria methodology to identify the best materials for lightweighting. • Employ state-of-the-art design tools for optimum material development for their specific applications. • Match new manufacturing technology to production volume. • Address new process variability with new production-ready processes.

  11. Proceedings of the 4th Annual Workshop: Advances in Smart Materials for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Hardy, Robin C. (Editor); Simpson, Joycelyn O. (Editor)

    1996-01-01

    The objective of the Fourth Annual Conference on Advances in Smart Materials for Aerospace Applications was to provide a forum for technical dialogue on numerous topics in the area of smart materials. The proceedings presented herein represent the technical contributions of the participants of the workshop. Topics addressed include shape memory alloys, ferroelectrics, fiber optics, finite element simulation, and active control.

  12. Literary Discussions and Advanced Speaking Functions: Researching the (Dis)Connection

    ERIC Educational Resources Information Center

    Donato, Richard; Brooks, Frank B.

    2004-01-01

    This study investigated the discourse of class discussion in the advanced undergraduate Spanish literature course. Motivating this study was the need for research to determine how discussion in advanced undergraduate literature courses provides discourse opportunities to students to develop advanced language functions, as defined in the ACTFL…

  13. Nanostructured material for advanced energy storage : magnesium battery cathode development.

    SciTech Connect

    Sigmund, Wolfgang M.; Woan, Karran V.; Bell, Nelson Simmons

    2010-11-01

    Magnesium batteries are alternatives to the use of lithium ion and nickel metal hydride secondary batteries due to magnesium's abundance, safety of operation, and lower toxicity of disposal. The divalency of the magnesium ion and its chemistry poses some difficulties for its general and industrial use. This work developed a continuous and fibrous nanoscale network of the cathode material through the use of electrospinning with the goal of enhancing performance and reactivity of the battery. The system was characterized and preliminary tests were performed on the constructed battery cells. We were successful in building and testing a series of electrochemical systems that demonstrated good cyclability maintaining 60-70% of discharge capacity after more than 50 charge-discharge cycles.

  14. Damage Prediction Models for Advanced Materials and Composites

    NASA Technical Reports Server (NTRS)

    Xie, Ming; Ahmad, Jalees; Grady, Joseph E. (Technical Monitor)

    2005-01-01

    In the present study, the assessment and evaluation of various acoustic tile designs were conducted using three-dimensional finite element analysis, which included static analysis, thermal analysis and modal analysis of integral and non-integral tile design options. Various benchmark specimens for acoustic tile designs, including CMC integral T-joint and notched CMC plate, were tested in both room and elevated temperature environment. Various candidate ceramic matrix composite materials were used in the numerical modeling and experimental study. The research effort in this program evolved from numerical modeling and concept design to a combined numerical analysis and experimental study. Many subjects associated with the design and performance of the acoustic tile in jet engine exhaust nozzle have been investigated.

  15. Advances in optical materials for large aperture lasers

    SciTech Connect

    Stokowski, S.E.; Lowdermilk, W.H.; Marchi, F.T.; Swain, J.E.; Wallerstein, E.P.; Wirtenson, G.R.

    1981-12-15

    Lawrence Livermore National Laboratory (LLNL) is using large aperture Nd: glass lasers to investigate the feasibility of inertial confinement fusion. In our experiments high power laser light is focussed onto a small (100 to 500 micron) target containing a deuterium-tritium fuel mixture. During the short (1 to 5 ns) laser pulse the fuel is compressed and heated, resulting in fusion reactions. The generation and control of the powerful laser pulses for these experiments is a challenging scientific and engineering task, which requires the development of new optical materials, fabrication techniques, and coatings. LLNL with the considerable cooperation and support from the optical industry, where most of the research and development and almost all the manufacturing is done, has successfully applied several new developments in these areas.

  16. A precision star tracker utilizing advanced techniques and materials

    NASA Technical Reports Server (NTRS)

    Gates, R. F.; Mcaloon, K. J.

    1976-01-01

    An image dissector star tracker has been developed which operates in the photon counting mode making it possible to utilize all digital electronics. A unique pulse processing circuit allows bright stars to be tracked as well as dim stars. Thermal mechanical stability has been greatly enhanced by fabricating a housing with graphite/epoxy composite material with a linear coefficient of thermal expansion near zero. Test results indicate the +10 Mv stars can be acquired and tracked, while position variation with star intensity is less than 2 arc seconds from 2.5 Mv to +10 Mv. The noise equivalent angle for a +8 Mv star is 3 arc seconds. Polynominal correction for remaining cross-coupling and nonlinearity reduced error over total 1 x 1 deg field to 1.5 arc seconds.

  17. Irradiation creep of candidate materials for advanced nuclear plants

    NASA Astrophysics Data System (ADS)

    Chen, J.; Jung, P.; Hoffelner, W.

    2013-10-01

    In the present paper, irradiation creep results of an intermetallic TiAl alloy and two ferritic oxide dispersion strengthened (ODS) steels are summarized. In situ irradiation creep measurements were performed using homogeneous implantation with α- and p-particles to maximum doses of 0.8 dpa at displacement damage rates of 2-8 × 10-6 dpa/s. The strains of miniaturized flat dog-bone specimens were monitored under uniaxial tensile stresses ranging from 20 to 400 MPa at temperatures of 573, 673 and 773 K, respectively. The effects of material composition, ODS particle size, and bombarding particle on the irradiation creep compliance was studied and results are compared to literature data. Evolution of microstructure during helium implantation was investigated in detail by TEM and is discussed with respect to irradiation creep models.

  18. Advances in Materials and System Technology for Portable Fuel Cells

    NASA Technical Reports Server (NTRS)

    Narayanan, Sekharipuram R.

    2007-01-01

    This viewgraph presentation describes the materials and systems engineering used for portable fuel cells. The contents include: 1) Portable Power; 2) Technology Solution; 3) Portable Hydrogen Systems; 4) Direct Methanol Fuel Cell; 5) Direct Methanol Fuel Cell System Concept; 6) Overview of DMFC R&D at JPL; 7) 300-Watt Portable Fuel Cell for Army Applications; 8) DMFC units from Smart Fuel Cell Inc, Germany; 9) DMFC Status and Prospects; 10) Challenges; 11) Rapid Screening of Well-Controlled Catalyst Compositions; 12) Screening of Ni-Zr-Pt-Ru alloys; 13) Issues with New Membranes; 14) Membranes With Reduced Methanol Crossover; 15) Stacks; 16) Hybrid DMFC System; 17) Small Compact Systems; 18) Durability; and 19) Stack and System Parameters for Various Applications.

  19. Advanced biomolecular materials based on membrane-protein/polymer complexation

    SciTech Connect

    Smith, G.S.; Nowak, A.; Safinya, C.

    1998-12-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of this project was to apply neutron reflectometry and atomic force microscopy to the study of lipid membranes containing proteins. Standard sample preparation techniques were used to produce thin films of these materials appropriate for these techniques. However, these films were not stable, and a new sample preparation technique was required. Toward this goal, the authors have developed a new capability to produce large, freely suspended films of lipid multi-bilayers appropriate for these studies. This system includes a controlled temperature/humidity oven in which the films 5-cm x 5-cm are remotely drawn. The first neutron scattering experiments were then performed using this oven.

  20. Design and development of advanced castable refractory materials

    NASA Astrophysics Data System (ADS)

    Davis, Robert Bruce

    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 Al

  1. Advanced materials and design for low temperature SOFCs

    DOEpatents

    Wachsman, Eric D.; Yoon, Heesung; Lee, Kang Taek; Camaratta, Matthew; Ahn, Jin Soo

    2016-05-17

    Embodiments of the invention are directed to SOFC with a multilayer structure comprising a porous ceramic cathode, optionally a cathodic triple phase boundary layer, a bilayer electrolyte comprising a cerium oxide comprising layer and a bismuth oxide comprising layer, an anion functional layer, and a porous ceramic anode with electrical interconnects, wherein the SOFC displays a very high power density at temperatures below 700.degree. C. with hydrogen or hydrocarbon fuels. The low temperature conversion of chemical energy to electrical energy allows the fabrication of the fuel cells using stainless steel or other metal alloys rather than ceramic conductive oxides as the interconnects.

  2. Cost benefit study of advanced materials technology for aircraft turbine engines

    NASA Technical Reports Server (NTRS)

    Hillery, R. V.; Johnston, R. P.

    1977-01-01

    The cost/benefits of eight advanced materials technologies were evaluated for two aircraft missions. The overall study was based on a time frame of commercial engine use of the advanced material technologies by 1985. The material technologies evaluated were eutectic turbine blades, titanium aluminide components, ceramic vanes, shrouds and combustor liners, tungsten composite FeCrAly blades, gamma prime oxide dispersion strengthened (ODS) alloy blades, and no coat ODS alloy combustor liners. They were evaluated in two conventional takeoff and landing missions, one transcontinental and one intercontinental.

  3. The DOE Center of Excellence for the Synthesis and Processing of Advanced Materials: Research briefs

    SciTech Connect

    1996-01-01

    This publication is designed to inform present and potential customers and partners of the DOE Center of Excellence for the Synthesis and Processing of Advanced Materials about significant advances resulting from Center-coordinated research. The format is an easy-to-read, not highly technical, concise presentation of the accomplishments. Selected accomplishments from each of the Center`s seven initial focused projects are presented. The seven projects are: (1) conventional and superplastic forming; (2) materials joining; (3) nanoscale materials for energy applications; (4) microstructural engineering with polymers; (5) tailored microstructures in hard magnets; (6) processing for surface hardness; and (7) mechanically reliable surface oxides for high-temperature corrosion resistance.

  4. New materials systems for advanced tribological and environmental applications

    NASA Astrophysics Data System (ADS)

    Xiao, Wei

    In this study, two different materials systems were developed to address current industrial problems of wear. The first system consisted of sterically hindered aliphatic polyester (SHAP) lubricants for use in hard disk magnetic recording applications. Specific goals included improved adhesion, durability and tribochemical stability compared to commercial perfluoropolyethers. While commercial perfluoropolyether lubricants are subject to catalytic degradation and mechanical scission, or suffer from severe stiction and dewetting problems, SHAP lubricants manifest greatly reduced stiction, superb thermal and oxidation stability, and excellent friction property, and make good candidates for broader applications, such as lubricants for MEMs or general purpose lubricants. The second material system involved a blend of Polytetrafluoroethylene (PTFE) and an Aromatic Thermosetting Polyester (ATSP) to achieve greatly improved mechanical properties and wear resistance compared to currently available blends of PTFE. The unique solid bonding capability and liquid crystalline nature of ATSP help form high aspect ratio microstructures, which allows fabrication of PTFE/ATSP composites across the entire composition range with greatly improved performance under greatly simplified conditions. A third project involved the design of new wide-spectrum antibacterial filters for point-of-use systems that are robust and can be easily regenerated and maintained. Silver coated fiberglass with colloidal sized silver particles was developed. Systems made of silver coated fiberglass are highly effective, have high capacity and can be regenerated easily. These disinfection units do not leach silver ions, or add taste or disinfection by-products into the treated water. Protozoa such as Cryptosporidium and Giardia can be held by the filter and destroyed during regeneration. They are an inexpensive, cleaner alternative to current point-of-use systems.

  5. Advanced Materials for RSOFC Dual Operation with Low Degradation

    SciTech Connect

    Eric, Tang; Tony, Wood; Sofiane, Benhaddad; Casey, Brown; Hongpeng, He; Jeff, Nelson; Oliver, Grande; Ben, Nuttall; Mark, Richards; Randy, Petri

    2012-12-27

    Reversible solid oxide fuel cells (RSOFCs) are energy conversion devices. They are capable of operating in both power generation mode (SOFC) and electrolysis modes (SOEC). RSOFC can integrate renewable production of electricity and hydrogen when power generation and steam electrolysis are coupled in a system, which can turn intermittent solar and wind energy into "firm power." In this DOE EERE project, VPS continuously advanced RSOFC cell stack technology in the areas of endurance and performance. Over 20 types of RSOFC cells were developed in the project. Many of those exceeded performance (area specific resistance less than 300 mohmcm2) and endurance (degradation rate less than 4% per 1000 hours) targets in both fuel cell and electrolysis modes at 750C. One of those cells, RSOFC-7, further demonstrated the following: Steady-state electrolysis with a degradation rate of 1.5% per 1000 hours. Ultra high current electrolysis over 3 A/cm2 at 75% water electrolysis efficiency voltage of 1.67 V. Daily SOFC/SOEC cyclic test of over 600 days with a degradation rate of 1.5% per 1000 hours. Over 6000 SOFC/SOEC cycles in an accelerated 20-minute cycling with degradation less than 3% per 1000 cycles. In RSOFC stack development, a number of kW-class RSOFC stacks were developed and demonstrated the following: Steady-state electrolysis operation of over 5000 hours. Daily SOFC/SOEC cyclic test of 100 cycles. Scale up capability of using large area cells with 550 cm2 active area showing the potential for large-scale RSOFC stack development in the future. Although this project is an open-ended development project, this effort, leveraging Versa Power Systems' years of development experience, has the potential to bring renewable energy RSOFC storage systems significantly closer to commercial viability through improvements in RSOFC durability, performance, and cost. When unitized and deployed in renewable solar and wind installations, an RSOFC system can enable higher availability for

  6. Advances in micro/nano scale materials processing by ultrafast lasers

    NASA Astrophysics Data System (ADS)

    Fotakis, Costas

    2009-03-01

    Materials processing by ultrafast lasers offers several attractive possibilities for micro/nano scale applications based on surface and in bulk laser induced modifications. The origin of these applications lies in the reduction of undesirable thermal effects, the non-equilibrium surface and volume structural modifications which may give rise to complex and unusual structures, the supression of photochemical effects in molecular substrates, the possibility of optimization of energy dissipation by temporal pulse shaping and the exploitation of filamentation effects. Diverse applications will be discussed, including the development and functionalization of laser engineered surfaces, the laser transfer of biomolecules and the functionalization of 3D structures constructed by multiphoton stereolithography. Two examples will be presented in this context: A new approach for the development of superhydrophobic, self-cleaning surfaces [1,2] and the fabrication of functional scaffolds for tissue engineering applications [3-5]. [4pt] References: [0pt] [1] V. Zorba et al., ``Biomimetic artificial surfaces quantitatively reproduce the water repellency of a Lotus leaf'', Advanced Materials 20, 4049 (2008).[0pt] [2] V. Zorba et al., ``Tailoring the wetting response of silicon surfaces via fs laser structuring'', Applied Physics A 93, 819 (2008).[0pt] [3] V. Dinca et al., ``Quantification of the activity of biomolecules in microarrays obtained by direct laser transfer'', Biomedical Microdevices 10, 719 (2008).[0pt] [4] B. Hopp et al., ``Laser-based techniques for living cell pattern formation'', Applied Physics A 93, 45 (2008).[0pt] [5] V. Dinca et al., ``Directed three-dimensional patterning of self-assembled peptide fibrils'', Nano Letters 8, 538 (2008).

  7. PREFACE: Advances in Cryogenic Engineering - Materials: Proceedings of the International Cryogenic Materials Conference (ICMC) 2015

    NASA Astrophysics Data System (ADS)

    Kittel, Peter; Sumption, Michael

    2015-12-01

    The 2015 joint Cryogenic Engineering and International Cryogenic Materials Conferences were held from June 28 through July 2 at the JW Marriott Starr Pass Resort & Spa in Tucson, Arizona. As at past conferences, the international scope of these meetings was strongly maintained with 26 countries being represented by 561 attendees who gathered to enjoy the joint technical programs, industrial exhibits, special events, and natural beauty of the surrounding Sonoran Desert. The program for the joint conferences included a total of 363 presentations in the plenary, oral, and poster sessions. Four plenary talks gave in-depth discussions of the readiness of bulk superconductors for applications, the role of cryogenics in the development of the hydrogen bomb and vice versa, superconducting turboelectric aircraft propulsion and UPS's uses and plans for LNG fuel. Contributed papers covered a wide range of topics including large-scale and small-scale cryogenics, advances in superconductors and their applications. In total, 234 papers were submitted for publication of which 224 are published in these proceedings. The CEC/ICMC Cryo Industrial Expo displayed the products and services of 38 industrial exhibitors and provided a congenial venue for a reception and refreshments throughout the week as well as the conference poster sessions. Spectacular panoramic views of Saguaro National Park, the Sonoran Desert and the night time lights of Tucson set the stage for a memorable week in the American Southwest. Conference participants enjoyed scenic hikes and bike rides, exploring Old Town Tucson, hot and spicy southwestern cuisine, a nighttime lightning display and a hailstorm. Conference Chairs for 2015 were Peter Kittel, Consultant, for CEC and Michael Sumption from The Ohio State University, Materials Science Department for ICMC. Program Chairs were Jonathan Demko from the LeTourneau University for CEC and Timothy Haugan from AFRL/RQQM for ICMC, assisted by the CEC Program Vice Chair

  8. Advanced materials based on carbon nanotube arrays, yarns and papers

    NASA Astrophysics Data System (ADS)

    Bradford, Phlip David

    Carbon nanotubes have hundreds of potential applications but require innovative processing techniques to manipulate the microscopic carbon dust into useful devices and products. This thesis describes efforts to process carbon nanotubes (CNTs) using novel methods with the goals of: (1) improving the properties of energy absorbing and composite carbon nanotube materials and (2) increasing understanding of fundamental structure-property relationships within these materials. Millimeter long CNTs, in the form of arrays, yarns and papers, were used to produce energy absorbing foams and high volume fraction CNT composites. Vertically aligned CNT arrays were grown on silicon substrates using chemical vapor deposition (CVD) of ethylene gas over iron nano-particles. The low density, millimeter thick arrays were tested under compression as energy absorbing foams. With additional CVD processing steps, it was possible to tune the compressive properties of the arrays. After the longest treatment, the compressive strength of the arrays was increased by a factor of 35 with a density increase of only six fold, while also imparting recovery from compression to the array. Microscopy revealed that the post-synthesis CVD treatment increased the number of CNT walls through an epitaxial type radial growth on the surface of the as-grown tubes. The increase in tube radius and mutual support between nanotubes explained the increases in compressive strength while an increase in nanotube roughness was proposed as the morphological change responsible for recovery in the array. Carbon nanotube yarns were used as the raw material for macroscopic textile preforms with a multi-level hierarchical carbon nanotube (CNT) structure: nanotubes, bundles, spun single yarns, plied yarns and 3-D braids. In prior tensile tests, composites produced from the 3-D braids exhibited unusual mechanical behavior effects. The proposed physical hypotheses explained those effects by molecular level interactions and

  9. Evaluation of advanced materials through experimental mechanics and modelling

    NASA Astrophysics Data System (ADS)

    Yang, Yii-Ching

    1993-11-01

    Composite materials have been frequently used in aerospace vehicles. Very often defects are inherited during the manufacture and damages are inherited during the construction and services. It becomes critical to understand the mechanical behavior of such composite structure before it can be further used. One good example of these composite structures is the cylindrical bottle of solid rocket motor case with accidental impact damages. Since the replacement of this cylindrical bottle is expensive, it is valuable to know how the damages affects the material, and how it can be repaired. To reach this goal, the damage must be characterized and the stress/strain field must be carefully analyzed. First the damage area, due to impact, is surveyed and identified with a shearography technique which uses the principle of speckle shearing interferometry to measure displacement gradient. Within the damage area of a composite laminate, such as the bottle of solid rocket motor case, all layers are considered to be degraded. Once a lamina being degraded the stiffness as well as strength will be drastically decreased. It becomes a critical area of failure to the whole bottle. And hence the stress/strain field within and around a damage should be accurately evaluated for failure prediction. To investigate the stress/strain field around damages a Hybrid-Numerical method which combines experimental measurement and finite element analysis is used. It is known the stress or strain at the singular point can not be accurately measured by an experimental technique. Nevertheless, if the location is far away from the singular spot, the displacement can be found accurately. Since it reflects the true displacement field locally regardless of the boundary conditions, it is an excellent input data for a finite element analysis to replace the usually assumed boundary conditions. Therefore, the Hybrid-Numerical method is chosen to avoid the difficulty and to take advantage of both experimental

  10. Evaluation of advanced materials through experimental mechanics and modelling

    NASA Technical Reports Server (NTRS)

    Yang, Yii-Ching

    1993-01-01

    Composite materials have been frequently used in aerospace vehicles. Very often defects are inherited during the manufacture and damages are inherited during the construction and services. It becomes critical to understand the mechanical behavior of such composite structure before it can be further used. One good example of these composite structures is the cylindrical bottle of solid rocket motor case with accidental impact damages. Since the replacement of this cylindrical bottle is expensive, it is valuable to know how the damages affects the material, and how it can be repaired. To reach this goal, the damage must be characterized and the stress/strain field must be carefully analyzed. First the damage area, due to impact, is surveyed and identified with a shearography technique which uses the principle of speckle shearing interferometry to measure displacement gradient. Within the damage area of a composite laminate, such as the bottle of solid rocket motor case, all layers are considered to be degraded. Once a lamina being degraded the stiffness as well as strength will be drastically decreased. It becomes a critical area of failure to the whole bottle. And hence the stress/strain field within and around a damage should be accurately evaluated for failure prediction. To investigate the stress/strain field around damages a Hybrid-Numerical method which combines experimental measurement and finite element analysis is used. It is known the stress or strain at the singular point can not be accurately measured by an experimental technique. Nevertheless, if the location is far away from the singular spot, the displacement can be found accurately. Since it reflects the true displacement field locally regardless of the boundary conditions, it is an excellent input data for a finite element analysis to replace the usually assumed boundary conditions. Therefore, the Hybrid-Numerical method is chosen to avoid the difficulty and to take advantage of both experimental

  11. High-resolution electron microscopy of advanced materials

    SciTech Connect

    Mitchell, T.E.; Kung, H.H.; Sickafus, K.E.; Gray, G.T. III; Field, R.D.; Smith, J.F.

    1997-11-01

    This final report chronicles a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The High-Resolution Electron Microscopy Facility has doubled in size and tripled in quality since the beginning of the three-year period. The facility now includes a field-emission scanning electron microscope, a 100 kV field-emission scanning transmission electron microscope (FE-STEM), a 300 kV field-emission high-resolution transmission electron microscope (FE-HRTEM), and a 300 kV analytical transmission electron microscope. A new orientation imaging microscope is being installed. X-ray energy dispersive spectrometers for chemical analysis are available on all four microscopes; parallel electron energy loss spectrometers are operational on the FE-STEM and FE-HRTEM. These systems enable evaluation of local atomic bonding, as well as chemical composition in nanometer-scale regions. The FE-HRTEM has a point-to-point resolution of 1.6 {angstrom}, but the resolution can be pushed to its information limit of 1 {angstrom} by computer reconstruction of a focal series of images. HRTEM has been used to image the atomic structure of defects such as dislocations, grain boundaries, and interfaces in a variety of materials from superconductors and ferroelectrics to structural ceramics and intermetallics.

  12. Advanced bearing materials for cryogenic aerospace engine turbopump requirements

    NASA Technical Reports Server (NTRS)

    Friedman, G.; Bhat, B. N.

    1986-01-01

    The properties of eleven alloys were investigated to select an improved bearing material for the High Pressure Oxygen Turbo Pump which delivers liquid oxygen to the Space Shuttle Main Engine. The alloys, selected through detailed literature analysis, X 405, MRC-2001, T440V, 14-4/6V, D-5, V-M Pyromet 350, Stellite 3, FerroTic CS-40, Tribaloy 800, WD-65, and CBS-600. The alloys were tested in hardness, corrosion resistance, wear resistance, fatigue resistance, and fracture toughness tests, and their performance was compared with the baseline 440C test alloy. As a result, five alloys were eliminated, leaving the remaining six (X 405, MRC-2001, T440V, 14-4/6V, D-5, and WD-65 to be evaluated in the next phase of NASA tests which will include fracture toughness, rolling contact fatigue, wear resistance, and corrosion resistance. From these, three alloys will be selected, which will be made into ninety bearings for subsequent testing.

  13. Prescriptive concepts for advanced nuclear materials control and accountability systems

    SciTech Connect

    Whitty, W.J.; Strittmatter, R.B.; Ford, W.; Tisinger, R.M.; Meyer, T.H.

    1987-06-01

    Networking- and distributed-processing hardware and software have the potential of greatly enhancing nuclear materials control and accountability (MC and A) systems, from both safeguards and process operations perspectives, while allowing timely integrated safeguards activities and enhanced computer security at reasonable cost. A hierarchical distributed system is proposed consisting of groups of terminal and instruments in plant production and support areas connected to microprocessors that are connected to either larger microprocessors or minicomputers. These micros and/or minis are connected to a main machine, which might be either a mainframe or a super minicomputer. Data acquisition, preliminary input data validation, and transaction processing occur at the lowest level. Transaction buffering, resource sharing, and selected data processing occur at the intermediate level. The host computer maintains overall control of the data base and provides routine safeguards and security reporting and special safeguards analyses. The research described outlines the distribution of MC and A system requirements in the hierarchical system and distributed processing applied to MC and A. Implications of integrated safeguards and computer security concepts for the distributed system design are discussed. 10 refs., 4 figs.

  14. Program to investigate advanced laser processing of materials

    NASA Astrophysics Data System (ADS)

    Breinan, E. M.; Snow, D. B.; Brown, C. O.

    1981-01-01

    This program included two major areas of research. In the processing area, a LAYERGLAZE (trade name) apparatus using a powder feed was developed and used to produce a 13.2 cm diameter by 3 cm thick cylindrical blank which was used as a preform for a scale model gas turbine disk. In addition to demonstrating that the process was capable of fabricating model size parts, mechanical testing and microstructural analysis of LAYERGLAZED material indicated that LAYERGLAZED parts exhibit good structural integrity and that the process produces no sizable or serious fabrication flaws provided that the alloy has adequate 'weldability' at high cooling rates. In a second major area, design of a LAYERGLAZE-processable superalloy was undertaken. With the system Ni-Al-Mo - X, numerous processable compositions were found, however, these compositions were characterized by embrittling phase transformations in the 600-800 deg temperature range. The research efforts in the alloy design area aimed at understanding and controlling this instability produced several alloys in the Ni-Al-Mo + X family which appeared to demonstrate the necessary characteristics of processability and phase stability. The mechanical properties of these alloys are being evaluated under an additional program. In addition to alloys from the above system, a number of additional alloys with high strength potentials have been developed based on other systems.

  15. Advanced Industrial Materials (AIM) Program: Compilation of project summaries and significant accomplishments, FY 1995

    SciTech Connect

    1996-04-01

    In many ways, the Advanced Industrial Materials (AIM) Program underwent a major transformation in Fiscal Year 1995 and these changes have continued to the present. When the Program was established in 1990 as the Advanced Industrial Concepts (AIC) Materials Program, the mission was to conduct applied research and development to bring materials and processing technologies from the knowledge derived from basic research to the maturity required for the end use sectors for commercialization. In 1995, the Office of Industrial Technologies (OIT) made radical changes in structure and procedures. All technology development was directed toward the seven ``Vision Industries`` that use about 80% of industrial energy and generated about 90% of industrial wastes. The mission of AIM has, therefore, changed to ``Support development and commercialization of new or improved materials to improve productivity, product quality, and energy efficiency in the major process industries.`` Though AIM remains essentially a National Laboratory Program, it is essential that each project have industrial partners, including suppliers to, and customers of, the seven industries. Now, well into FY 1996, the transition is nearly complete and the AIM Program remains reasonably healthy and productive, thanks to the superb investigators and Laboratory Program Managers. This report contains the technical details of some very remarkable work by the best materials scientists and engineers in the world. Subject areas covered are: advanced metals and composites; advanced ceramics and composites; polymers and biobased materials; and new materials and processes.

  16. Advanced bulk processing of lightweight materials for utilization in the transportation sector

    NASA Astrophysics Data System (ADS)

    Milner, Justin L.

    The overall objective of this research is to develop the microstructure of metallic lightweight materials via multiple advanced processing techniques with potentials for industrial utilization on a large scale to meet the demands of the aerospace and automotive sectors. This work focused on (i) refining the grain structure to increase the strength, (ii) controlling the texture to increase formability and (iii) directly reducing processing/production cost of lightweight material components. Advanced processing is conducted on a bulk scale by several severe plastic deformation techniques including: accumulative roll bonding, isolated shear rolling and friction stir processing to achieve the multiple targets of this research. Development and validation of the processing techniques is achieved through wide-ranging experiments along with detailed mechanical and microstructural examination of the processed material. On a broad level, this research will make advancements in processing of bulk lightweight materials facilitating industrial-scale implementation. Where accumulative roll bonding and isolated shear rolling, currently feasible on an industrial scale, processes bulk sheet materials capable of replacing more expensive grades of alloys and enabling low-temperature and high-strain-rate formability. Furthermore, friction stir processing to manufacture lightweight tubes, made from magnesium alloys, has the potential to increase the utilization of these materials in the automotive and aerospace sectors for high strength - high formability applications. With the increased utilization of these advanced processing techniques will significantly reduce the cost associated with lightweight materials for many applications in the transportation sectors.

  17. Some functional properties of composite material based on scrap tires

    NASA Astrophysics Data System (ADS)

    Plesuma, Renate; Malers, Laimonis

    2013-09-01

    The utilization of scrap tires still obtains a remarkable importance from the aspect of unloading the environment from non-degradable waste [1]. One of the most prospective ways for scrap tires reuse is a production of composite materials [2] This research must be considered as a continuation of previous investigations [3, 4]. It is devoted to the clarification of some functional properties, which are considered important for the view of practical applications, of the composite material. Some functional properties of the material were investigated, for instance, the compressive stress at different extent of deformation of sample (till 67% of initial thickness) (LVS EN 826) [5] and the resistance to UV radiation (modified method based on LVS EN 14836) [6]. Experiments were realized on the purposefully selected samples. The results were evaluated in the correlation with potential changes of Shore C hardness (Shore scale, ISO 7619-1, ISO 868) [7, 8]. The results showed noticeable resistance of the composite material against the mechanical influence and ultraviolet (UV) radiation. The correlation with the composition of the material, activity of binder, definite technological parameters, and the conditions supported during the production, were determined. It was estimated that selected properties and characteristics of the material are strongly dependent from the composition and technological parameters used in production of the composite material, and from the size of rubber crumb. Obtained results show possibility to attain desirable changes in the composite material properties by changing both the composition and technological parameters of examined material.

  18. Materials for advanced turbine engines. Volume 1: Advanced blade tip seal system

    NASA Technical Reports Server (NTRS)

    Zelahy, J. W.; Fairbanks, N. P.

    1982-01-01

    Project 3, the subject of this technical report, was structured toward the successful engine demonstration of an improved-efficiency, long-life, tip-seal system for turbine blades. The advanced tip-seal system was designed to maintain close operating clearances between turbine blade tips and turbine shrouds and, at the same time, be resistant to environmental effects including high-temperature oxidation, hot corrosion, and thermal cycling. The turbine blade tip comprised an environmentally resistant, activated-diffussion-bonded, monocrystal superalloy combined with a thin layer of aluminium oxide abrasive particles entrapped in an electroplated NiCr matrix. The project established the tip design and joint location, characterized the single-crystal tip alloy and abrasive tip treatment, and established the manufacturing and quality-control plans required to fully process the blades. A total of 171 blades were fully manufactured, and 100 were endurance and performance engine-tested.

  19. Advanced Materials for PEM-Based Fuel Cell Systems

    SciTech Connect

    James E. McGrath; Donald G. Baird; Michael von Spakovsky

    2005-10-26

    Proton exchange membrane fuel cells (PEMFCs) are quickly becoming attractive alternative energy sources for transportation, stationary power, and small electronics due to the increasing cost and environmental hazards of traditional fossil fuels. Two main classes of PEMFCs include hydrogen/air or hydrogen/oxygen fuel cells and direct methanol fuel cells (DMFCs). The current benchmark membrane for both types of PEMFCs is Nafion, a perfluorinated sulfonated copolymer made by DuPont. Nafion copolymers exhibit good thermal and chemical stability, as well as very high proton conductivity under hydrated conditions at temperatures below 80 degrees C. However, application of these membranes is limited due to their high methanol permeability and loss of conductivity at high temperatures and low relative humidities. These deficiencies have led to the search for improved materials for proton exchange membranes. Potential PEMs should have good thermal, hydrolytic, and oxidative stability, high proton conductivity, selective permeability, and mechanical durability over long periods of time. Poly(arylene ether)s, polyimides, polybenzimidazoles, and polyphenylenes are among the most widely investigated candidates for PEMs. Poly(arylene ether)s are a promising class of proton exchange membranes due to their excellent thermal and chemical stability and high glass transition temperatures. High proton conductivity can be achieved through post-sulfonation of poly(arylene ether) materials, but this most often results in very high water sorption or even water solubility. Our research has shown that directly polymerized poly(arylene ether) copolymers show important advantages over traditional post-sulfonated systems and also address the concerns with Nafion membranes. These properties were evaluated and correlated with morphology, structure-property relationships, and states of water in the membranes. Further improvements in properties were achieved through incorporation of inorganic

  20. Advanced Materials for PEM-Based Fuel Cell Systems

    SciTech Connect

    James E. McGrath

    2005-10-26

    Proton exchange membrane fuel cells (PEMFCs) are quickly becoming attractive alternative energy sources for transportation, stationary power, and small electronics due to the increasing cost and environmental hazards of traditional fossil fuels. Two main classes of PEMFCs include hydrogen/air or hydrogen/oxygen fuel cells and direct methanol fuel cells (DMFCs). The current benchmark membrane for both types of PEMFCs is Nafion, a perfluorinated sulfonated copolymer made by DuPont. Nafion copolymers exhibit good thermal and chemical stability, as well as very high proton conductivity under hydrated conditions at temperatures below 80 °C. However, application of these membranes is limited due to their high methanol permeability and loss of conductivity at high temperatures and low relative humidities. These deficiencies have led to the search for improved materials for proton exchange membranes. Potential PEMs should have good thermal, hydrolytic, and oxidative stability, high proton conductivity, selective permeability, and mechanical durability over long periods of time. Poly(arylene ether)s, polyimides, polybenzimidazoles, and polyphenylenes are among the most widely investigated candidates for PEMs. Poly(arylene ether)s are a promising class of proton exchange membranes due to their excellent thermal and chemical stability and high glass transition temperatures. High proton conductivity can be achieved through post-sulfonation of poly(arylene ether) materials, but this most often results in very high water sorption or even water solubility. Our research has shown that directly polymerized poly(arylene ether) copolymers show important advantages over traditional post-sulfonated systems and also address the concerns with Nafion membranes. These properties were evaluated and correlated with morphology, structure-property relationships, and