Superhydrophobic materials for biomedical applications.

PubMed

Falde, Eric J; Yohe, Stefan T; Colson, Yolonda L; Grinstaff, Mark W

2016-10-01

Superhydrophobic surfaces are actively studied across a wide range of applications and industries, and are now finding increased use in the biomedical arena as substrates to control protein adsorption, cellular interaction, and bacterial growth, as well as platforms for drug delivery devices and for diagnostic tools. The commonality in the design of these materials is to create a stable or metastable air layer at the material surface, which lends itself to a number of unique properties. These activities are catalyzing the development of new materials, applications, and fabrication techniques, as well as collaborations across material science, chemistry, engineering, and medicine given the interdisciplinary nature of this work. The review begins with a discussion of superhydrophobicity, and then explores biomedical applications that are utilizing superhydrophobicity in depth including material selection characteristics, in vitro performance, and in vivo performance. General trends are offered for each application in addition to discussion of conflicting data in the literature, and the review concludes with the authors' future perspectives on the utility of superhydrophobic biomaterials for medical applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Intrinsically High Thermoelectric Performance in AgInSe2 n-Type Diamond-Like Compounds.

PubMed

Qiu, Pengfei; Qin, Yuting; Zhang, Qihao; Li, Ruoxi; Yang, Jiong; Song, Qingfeng; Tang, Yunshan; Bai, Shengqiang; Shi, Xun; Chen, Lidong

2018-03-01

Diamond-like compounds are a promising class of thermoelectric materials, very suitable for real applications. However, almost all high-performance diamond-like thermoelectric materials are p-type semiconductors. The lack of high-performance n-type diamond-like thermoelectric materials greatly restricts the fabrication of diamond-like material-based modules and their real applications. In this work, it is revealed that n-type AgInSe 2 diamond-like compound has intrinsically high thermoelectric performance with a figure of merit ( zT ) of 1.1 at 900 K, comparable to the best p-type diamond-like thermoelectric materials reported before. Such high zT is mainly due to the ultralow lattice thermal conductivity, which is fundamentally limited by the low-frequency Ag-Se "cluster vibrations," as confirmed by ab initio lattice dynamic calculations. Doping Cd at Ag sites significantly improves the thermoelectric performance in the low and medium temperature ranges. By using such high-performance n-type AgInSe 2 -based compounds, the diamond-like thermoelectric module has been fabricated for the first time. An output power of 0.06 W under a temperature difference of 520 K between the two ends of the module is obtained. This work opens a new window for the applications using the diamond-like thermoelectric materials.

Development of Perovskite-Type Materials for Thermoelectric Application.

PubMed

Wu, Tingjun; Gao, Peng

2018-06-12

Oxide perovskite materials have a long history of being investigated for thermoelectric applications. Compared to the state-of-the-art tin and lead chalcogenides, these perovskite compounds have advantages of low toxicity, eco-friendliness, and high elemental abundance. However, because of low electrical conductivity and high thermal conductivity, the total thermoelectric performance of oxide perovskites is relatively poor. Variety of methods were used to enhance the TE properties of oxide perovskite materials, such as doping, inducing oxygen vacancy, embedding crystal imperfection, and so on. Recently, hybrid perovskite materials started to draw attention for thermoelectric application. Due to the low thermal conductivity and high Seebeck coefficient feature of hybrid perovskites materials, they can be promising thermoelectric materials and hold the potential for the application of wearable energy generators and cooling devices. This mini-review will build a bridge between oxide perovskites and burgeoning hybrid halide perovskites in the research of thermoelectric properties with an aim to further enhance the relevant performance of perovskite-type materials.

Fabrication of Advanced Thermoelectric Materials by Hierarchical Nanovoid Generation

NASA Technical Reports Server (NTRS)

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

An overview of active flow control actuators and applications (presentation video)

NASA Astrophysics Data System (ADS)

Brzozowski, Daniel; Whalen, Edward A.

2014-04-01

Active Flow Control (AFC) is an emerging technology which promises performance enhancements to both military and civilian aircraft. A technique which uses energy input at discrete locations to manipulate the flow over an aerodynamic surface, AFC may be used to reduce drag, prevent flow separation, and enable otherwise-infeasible aerodynamic designs. Additional applications include shear layer and turbulence control for aero-optics applications and mixing enhancement for thermal applications. Many AFC applications call for a high frequency fluidic perturbation provided by an electrically-powered actuator. In these instances, piezoelectric (PZT) materials have served as the workhorse for flow control actuators, such as the widely-studied synthetic jet. Because the PZT materials form the critical component of the actuator, the maximum performance of the synthetic jet (velocity and momentum output) is limited by the physical limitations of the PZT material. The purpose of this presentation is to provide a high level overview of AFC actuators and applications in an attempt to engage the smart materials community and encourage advanced material development in support of these crucial applications.

Performance Testing of Thermal Interface Filler Materials in a Bolted Aluminum Interface Under Thermal/Vacuum Conditions

NASA Technical Reports Server (NTRS)

Glasgow, S. D.; Kittredge, K. B.

2003-01-01

A thermal interface material is one of the many tools often used as part of the thermal control scheme for space-based applications. Historically, at Marshall Space Flight Center, CHO-THERM 1671 has primarily been used for applications where an interface material was deemed necessary. However, numerous alternatives have come on the market in recent years. It was decided that a number of these materials should be tested against each other to see if there were better performing alternatives. The tests were done strictly to compare the thermal performance of the materials relative to each other under repeatable conditions and do not take into consideration other design issues, such as off-gassing, electrical conduction, isolation, etc. The purpose of this Technical Memorandum is to detail the materials tested, test apparatus, procedures, and results of these tests. The results show that there are a number of better performing alternatives now available.

Power Electronic Semiconductor Materials for Automotive and Energy Saving Applications - SiC, GaN, Ga2O3, and Diamond.

PubMed

Wellmann, Peter J

2017-11-17

Power electronics belongs to the future key technologies in order to increase system efficiency as well as performance in automotive and energy saving applications. Silicon is the major material for electronic switches since decades. Advanced fabrication processes and sophisticated electronic device designs have optimized the silicon electronic device performance almost to their theoretical limit. Therefore, to increase the system performance, new materials that exhibit physical and chemical properties beyond silicon need to be explored. A number of wide bandgap semiconductors like silicon carbide, gallium nitride, gallium oxide, and diamond exhibit outstanding characteristics that may pave the way to new performance levels. The review will introduce these materials by (i) highlighting their properties, (ii) introducing the challenges in materials growth, and (iii) outlining limits that need innovation steps in materials processing to outperform current technologies.

Power Electronic Semiconductor Materials for Automotive and Energy Saving Applications – SiC, GaN, Ga2O3, and Diamond

PubMed Central

2017-01-01

Power electronics belongs to the future key technologies in order to increase system efficiency as well as performance in automotive and energy saving applications. Silicon is the major material for electronic switches since decades. Advanced fabrication processes and sophisticated electronic device designs have optimized the silicon electronic device performance almost to their theoretical limit. Therefore, to increase the system performance, new materials that exhibit physical and chemical properties beyond silicon need to be explored. A number of wide bandgap semiconductors like silicon carbide, gallium nitride, gallium oxide, and diamond exhibit outstanding characteristics that may pave the way to new performance levels. The review will introduce these materials by (i) highlighting their properties, (ii) introducing the challenges in materials growth, and (iii) outlining limits that need innovation steps in materials processing to outperform current technologies. PMID:29200530

Nonlinear Constitutive Relations for High Temperature Application, 1984

NASA Technical Reports Server (NTRS)

1985-01-01

Nonlinear constitutive relations for high temperature applications were discussed. The state of the art in nonlinear constitutive modeling of high temperature materials was reviewed and the need for future research and development efforts in this area was identified. Considerable research efforts are urgently needed in the development of nonlinear constitutive relations for high temperature applications prompted by recent advances in high temperature materials technology and new demands on material and component performance. Topics discussed include: constitutive modeling, numerical methods, material testing, and structural applications.

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

NREL developed a modeling and experimental strategy to characterize thermal performance of materials. The technique provides critical data on thermal properties with relevance for electronics packaging applications. Thermal contact resistance and bulk thermal conductivity were characterized for new high-performance materials such as thermoplastics, boron-nitride nanosheets, copper nanowires, and atomically bonded layers. The technique is an important tool for developing designs and materials that enable power electronics packaging with small footprint, high power density, and low cost for numerous applications.

Cryogenic Fracture Toughness Evaluation of an Investment Cast Al-Be Alloy for Structural Applications

NASA Technical Reports Server (NTRS)

Gamwell, W. R.; McGill, P. B.

2006-01-01

Aluminum-Beryllium metal matrix composite materials are useful due to their desirable performance characteristics for aerospace applications. Desirable characteristics of this material includes light-weight, dimensional stability, stiffness, good vibration damping characteristics, low coefficient of thermal expansion, and workability, This material is 3.5 times stiffer and 22% lighter than conventional aluminum alloys. electro-optical systems, advanced sensor and guidance components for flight and satellite systems, components for light-weight high-performance aircraft engines, and structural components for helicopters. Aluminum-beryllium materials are now available in the form of near net shape investment castings. In this materials properties characterization study, the cryogenic tensile and fracture properties of an investment casting alloy, Beralcast 363, were determined. Tensile testing was performed at 21 C (70 F), -73.3 C (-100 F), -195.5 C (-320 F) and -252.8 C (-423 F), and fracture (K(sub lc) and da/dN) testing was performed at -73.3 C (-100 F), -195.5 C (-320 F) and -252.8 C (-423 F). Their use is attractive for weight critical structural applications such as advanced

Developing improved silica materials and devices for integrated optics applications

NASA Astrophysics Data System (ADS)

Maker, Ashley Julia

Due to their favorable optical and material properties, silica-based materials and devices have found many important applications throughout science and engineering, especially in sensing, communications, lasers, and integrated optics. Often, silica's properties ultimately limit the performance of these applications. To address this limitation, this thesis investigates the development of improved silica materials and optical devices, including silica films, coatings, waveguides, resonators, lasers, and sensors. Using sol-gel chemistry and microfabrication procedures, custom silica materials and devices are developed to benefit many applications. In this thesis, it is first demonstrated how the low optical loss of silica enables fabrication of low loss integrated waveguides and toroidal resonators with ultra-high quality factors. Then, by adding various rare earth and metal dopants to sol-gel silica, hybrid silica materials and devices are made with custom properties such as high refractive index and lasing capabilities. Finally, several applications are demonstrated, including the use of high refractive index coatings to control the behavior of light, development of Raman and ultra-low threshold rare earth microlasers, and a heterodyned microlaser sensor with significantly improved sensing performance. Future applications and directions of this research are also discussed.

Developing polymer composite materials: carbon nanotubes or graphene?

PubMed

Sun, Xuemei; Sun, Hao; Li, Houpu; Peng, Huisheng

2013-10-04

The formation of composite materials represents an efficient route to improve the performances of polymers and expand their application scopes. Due to the unique structure and remarkable mechanical, electrical, thermal, optical and catalytic properties, carbon nanotube and graphene have been mostly studied as a second phase to produce high performance polymer composites. Although carbon nanotube and graphene share some advantages in both structure and property, they are also different in many aspects including synthesis of composite material, control in composite structure and interaction with polymer molecule. The resulting composite materials are distinguished in property to meet different applications. This review article mainly describes the preparation, structure, property and application of the two families of composite materials with an emphasis on the difference between them. Some general and effective strategies are summarized for the development of polymer composite materials based on carbon nanotube and graphene. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Recent progress in nanostructured next-generation field emission devices

NASA Astrophysics Data System (ADS)

Mittal, Gaurav; Lahiri, Indranil

2014-08-01

Field emission has been known to mankind for more than a century, and extensive research in this field for the last 40-50 years has led to development of exciting applications such as electron sources, miniature x-ray devices, display materials, etc. In the last decade, large-area field emitters were projected as an important material to revolutionize healthcare and medical devices, and space research. With the advent of nanotechnology and advancements related to carbon nanotubes, field emitters are demonstrating highly enhanced performance and novel applications. Next-generation emitters need ultra-high emission current density, high brightness, excellent stability and reproducible performance. Novel design considerations and application of new materials can lead to achievement of these capabilities. This article presents an overview of recent developments in this field and their effects on improved performance of field emitters. These advancements are demonstrated to hold great potential for application in next-generation field emission devices.

Development of heat-storage building materials for passive-solar applications

NASA Astrophysics Data System (ADS)

Fletcher, J. W.

A heat storage building material to be used for passive solar applications and general load leveling within building spaces was developed. Specifically, PCM-filled plastic panels are to be developed as wallboard and ceiling panels. Three PCMs (CaCl2, 6H2O; Na2SO4, 10H2O; LiNO3, 3H2O are to be evaluated for use in the double walled, hollow channeled plastic panels. Laboratory development of the panels will include determination of filling and sealing techniques, behavior of the PCMs, container properties and materials compatibility. Testing will include vapor transmission, thermal cycle, dynamic performance, accelerated life and durability tests. In addition to development and testing, an applications analysis will be performed for specific passive solar applications. Conceptual design of a single family passive solar residence will be prepared and performance evaluated. Screening of the three PCM candidates is essentially complete.

Performance analysis of advanced spacecraft TPS

NASA Technical Reports Server (NTRS)

Pitts, William C.

1991-01-01

Spacecraft entering a planetary atmosphere require a very sophisticated thermal protection system. The materials used must be tailored to each specific vehicle based on its planned mission profiles. Starting with the Space Shuttle, many types of ceramic insulation with various combinations of thermal properties have been developed by others. The development of two new materials is described: A Composite Flexible Blanket Insulation which has a significantly lower effective thermal conductivity than other ceramic blankets; and a Silicon Matrix Composite which has applications at high temperature locations such as wing leading edges. Also, a systematic study is described that considers the application of these materials for a proposed Personnel Launch System. The study shows how most of these available ceramic materials would perform during atmospheric entry of this vehicle. Other specific applications of these thermal protection materials are discussed.

Bionic Design, Materials and Performance of Bone Tissue Scaffolds

PubMed Central

Wu, Tong; Yu, Suihuai; Chen, Dengkai; Wang, Yanen

2017-01-01

Design, materials, and performance are important factors in the research of bone tissue scaffolds. This work briefly describes the bone scaffolds and their anatomic structure, as well as their biological and mechanical characteristics. Furthermore, we reviewed the characteristics of metal materials, inorganic materials, organic polymer materials, and composite materials. The importance of the bionic design in preoperative diagnosis models and customized bone scaffolds was also discussed, addressing both the bionic structure design (macro and micro structure) and the bionic performance design (mechanical performance and biological performance). Materials and performance are the two main problems in the development of customized bone scaffolds. Bionic design is an effective way to solve these problems, which could improve the clinical application of bone scaffolds, by creating a balance between mechanical performance and biological performance. PMID:29039749

Bionic Design, Materials and Performance of Bone Tissue Scaffolds.

PubMed

Wu, Tong; Yu, Suihuai; Chen, Dengkai; Wang, Yanen

2017-10-17

Design, materials, and performance are important factors in the research of bone tissue scaffolds. This work briefly describes the bone scaffolds and their anatomic structure, as well as their biological and mechanical characteristics. Furthermore, we reviewed the characteristics of metal materials, inorganic materials, organic polymer materials, and composite materials. The importance of the bionic design in preoperative diagnosis models and customized bone scaffolds was also discussed, addressing both the bionic structure design (macro and micro structure) and the bionic performance design (mechanical performance and biological performance). Materials and performance are the two main problems in the development of customized bone scaffolds. Bionic design is an effective way to solve these problems, which could improve the clinical application of bone scaffolds, by creating a balance between mechanical performance and biological performance.

Nacre-inspired composites with different macroscopic dimensions: strategies for improved mechanical performance and applications

NASA Astrophysics Data System (ADS)

Zhao, Hewei; Yang, Zhao; Guo, Lin

2018-04-01

To develop next-generation lightweight, high-strength, and tough materials, new materials design strategies must be established. Nacre, consisting of 95 vol.% inorganic plates (CaCO3) and 5 vol.% organic matrix (protein) in layered arrangements, is famous for its significant increase (three orders of magnitude higher) in toughness compared to monolithic aragonite and has always been the model for the synthesis of high mechanical performance artificial materials. In this review, we primarily introduce the recent studies on the synthesis of nacre-inspired composites with exceptional mechanical properties, including 1D fibers, 2D films, and 3D bulk materials. In addition, design strategies for performance enhancement are summarized based on these studies, and applications of high-performance nacre-inspired composites are also discussed. Finally, a critical outlook of the future direction of developing next-generation high mechanical performance nacre-inspired composites is provided.

Electronics materials research

NASA Technical Reports Server (NTRS)

1982-01-01

The electronic materials and is aimed at the establishment of quantitative relationships underlying crystal growth parameters, materials properties, electronic characteristics and device applications. The overall program evolves about the following main thrust areas: (1) crystal growth novel approaches to engineering of semiconductor materials; (2) investigation of materials properties and electronic characteristics on a macro and microscale; (3) surface properties and surface interactions with the bulk and ambients; (4) electronic properties controlling device applications and device performance.

3D graphene nanomaterials for binder-free supercapacitors: scientific design for enhanced performance.

PubMed

He, Shuijian; Chen, Wei

2015-04-28

Because of the excellent intrinsic properties, especially the strong mechanical strength, extraordinarily high surface area and extremely high conductivity, graphene is deemed as a versatile building block for fabricating functional materials for energy production and storage applications. In this article, the recent progress in the assembly of binder-free and self-standing graphene-based materials, as well as their application in supercapacitors are reviewed, including electrical double layer capacitors, pseudocapacitors, and asymmetric supercapacitors. Various fabrication strategies and the influence of structures on the capacitance performance of 3D graphene-based materials are discussed. We finally give concluding remarks and an outlook on the scientific design of binder-free and self-standing graphene materials for achieving better capacitance performance.

3D graphene nanomaterials for binder-free supercapacitors: scientific design for enhanced performance

NASA Astrophysics Data System (ADS)

He, Shuijian; Chen, Wei

2015-04-01

Because of the excellent intrinsic properties, especially the strong mechanical strength, extraordinarily high surface area and extremely high conductivity, graphene is deemed as a versatile building block for fabricating functional materials for energy production and storage applications. In this article, the recent progress in the assembly of binder-free and self-standing graphene-based materials, as well as their application in supercapacitors are reviewed, including electrical double layer capacitors, pseudocapacitors, and asymmetric supercapacitors. Various fabrication strategies and the influence of structures on the capacitance performance of 3D graphene-based materials are discussed. We finally give concluding remarks and an outlook on the scientific design of binder-free and self-standing graphene materials for achieving better capacitance performance.

Manganese oxide-based materials as electrochemical supercapacitor electrodes.

PubMed

Wei, Weifeng; Cui, Xinwei; Chen, Weixing; Ivey, Douglas G

2011-03-01

Electrochemical supercapacitors (ECs), characteristic of high power and reasonably high energy densities, have become a versatile solution to various emerging energy applications. This critical review describes some materials science aspects on manganese oxide-based materials for these applications, primarily including the strategic design and fabrication of these electrode materials. Nanostructurization, chemical modification and incorporation with high surface area, conductive nanoarchitectures are the three major strategies in the development of high-performance manganese oxide-based electrodes for EC applications. Numerous works reviewed herein have shown enhanced electrochemical performance in the manganese oxide-based electrode materials. However, many fundamental questions remain unanswered, particularly with respect to characterization and understanding of electron transfer and atomic transport of the electrochemical interface processes within the manganese oxide-based electrodes. In order to fully exploit the potential of manganese oxide-based electrode materials, an unambiguous appreciation of these basic questions and optimization of synthesis parameters and material properties are critical for the further development of EC devices (233 references).

Intrinsically High Thermoelectric Performance in AgInSe2 n‐Type Diamond‐Like Compounds

PubMed Central

Qiu, Pengfei; Qin, Yuting; Zhang, Qihao; Li, Ruoxi; Song, Qingfeng; Tang, Yunshan; Bai, Shengqiang

2017-01-01

Abstract Diamond‐like compounds are a promising class of thermoelectric materials, very suitable for real applications. However, almost all high‐performance diamond‐like thermoelectric materials are p‐type semiconductors. The lack of high‐performance n‐type diamond‐like thermoelectric materials greatly restricts the fabrication of diamond‐like material‐based modules and their real applications. In this work, it is revealed that n‐type AgInSe2 diamond‐like compound has intrinsically high thermoelectric performance with a figure of merit (zT) of 1.1 at 900 K, comparable to the best p‐type diamond‐like thermoelectric materials reported before. Such high zT is mainly due to the ultralow lattice thermal conductivity, which is fundamentally limited by the low‐frequency Ag‐Se “cluster vibrations,” as confirmed by ab initio lattice dynamic calculations. Doping Cd at Ag sites significantly improves the thermoelectric performance in the low and medium temperature ranges. By using such high‐performance n‐type AgInSe2‐based compounds, the diamond‐like thermoelectric module has been fabricated for the first time. An output power of 0.06 W under a temperature difference of 520 K between the two ends of the module is obtained. This work opens a new window for the applications using the diamond‐like thermoelectric materials. PMID:29593972

Functionalized graphene and other two-dimensional materials for photovoltaic devices: device design and processing.

PubMed

Liu, Zhike; Lau, Shu Ping; Yan, Feng

2015-08-07

Graphene is the thinnest two-dimensional (2D) carbon material and has many advantages including high carrier mobilities and conductivity, high optical transparency, excellent mechanical flexibility and chemical stability, which make graphene an ideal material for various optoelectronic devices. The major applications of graphene in photovoltaic devices are for transparent electrodes and charge transport layers. Several other 2D materials have also shown advantages in charge transport and light absorption over traditional semiconductor materials used in photovoltaic devices. Great achievements in the applications of 2D materials in photovoltaic devices have been reported, yet numerous challenges still remain. For practical applications, the device performance should be further improved by optimizing the 2D material synthesis, film transfer, surface functionalization and chemical/physical doping processes. In this review, we will focus on the recent advances in the applications of graphene and other 2D materials in various photovoltaic devices, including organic solar cells, Schottky junction solar cells, dye-sensitized solar cells, quantum dot-sensitized solar cells, other inorganic solar cells, and perovskite solar cells, in terms of the functionalization techniques of the materials, the device design and the device performance. Finally, conclusions and an outlook for the future development of this field will be addressed.

Study of materials performance model for aircraft interiors

NASA Technical Reports Server (NTRS)

Leary, K.; Skratt, J.

1980-01-01

A demonstration version of an aircraft interior materials computer data library was developed and contains information on selected materials applicable to aircraft seats and wall panels, including materials for the following: panel face sheets, bond plies, honeycomb, foam, decorative film systems, seat cushions, adhesives, cushion reinforcements, fire blocking layers, slipcovers, decorative fabrics and thermoplastic parts. The information obtained for each material pertains to the material's performance in a fire scenario, selected material properties and several measures of processability.

Performance Testing of Thermal Interface Filler Materials in a Bolted Aluminum Interface Under Thermal/Vacuum Conditions

NASA Technical Reports Server (NTRS)

Glasgow, Shaun; Kittredge, Ken

2003-01-01

A thermal interface material is one of the many tools that are often used as part of the thermal control scheme for space-based applications. These materials are placed between, for example, an avionics box and a cold plate, in order to improve the conduction heat transfer so that proper temperatures can be maintained. Historically at Marshall Space Flight Center, CHO-THERM@ 1671 has primarily been used for applications where an interface material was deemed necessary. However, there have been numerous alternatives come on the market in recent years. It was decided that a number of these materials should be tested against each other to see if there were better performing alternatives. The tests were done strictly to compare the thermal performance of the materials relative to each other under repeatable conditions and they do not take into consideration other design issues such as off-gassing, electrical conduction or isolation, etc. This paper details the materials tested, test apparatus, procedures, and results of these tests.

Application of Ni-Oxide@TiO₂ Core-Shell Structures to Photocatalytic Mixed Dye Degradation, CO Oxidation, and Supercapacitors.

PubMed

Lee, Seungwon; Lee, Jisuk; Nam, Kyusuk; Shin, Weon Gyu; Sohn, Youngku

2016-12-20

Performing diverse application tests on synthesized metal oxides is critical for identifying suitable application areas based on the material performances. In the present study, Ni-oxide@TiO₂ core-shell materials were synthesized and applied to photocatalytic mixed dye (methyl orange + rhodamine + methylene blue) degradation under ultraviolet (UV) and visible lights, CO oxidation, and supercapacitors. Their physicochemical properties were examined by field-emission scanning electron microscopy, X-ray diffraction analysis, Fourier-transform infrared spectroscopy, and UV-visible absorption spectroscopy. It was shown that their performances were highly dependent on the morphology, thermal treatment procedure, and TiO₂ overlayer coating.

Instrument for Measuring Thermal Conductivity of Materials at Low Temperatures

NASA Technical Reports Server (NTRS)

Fesmire, James; Sass, Jared; Johnson, Wesley

2010-01-01

With the advance of polymer and other non-metallic material sciences, whole new series of polymeric materials and composites are being created. These materials are being optimized for many different applications including cryogenic and low-temperature industrial processes. Engineers need these data to perform detailed system designs and enable new design possibilities for improved control, reliability, and efficiency in specific applications. One main area of interest is cryogenic structural elements and fluid handling components and other parts, films, and coatings for low-temperature application. An important thermal property of these new materials is the apparent thermal conductivity (k-value).

Energy Efficient Graphene Based High Performance Capacitors.

PubMed

Bae, Joonwon; Kwon, Oh Seok; Lee, Chang-Soo

2017-07-10

Graphene (GRP) is an interesting class of nano-structured electronic materials for various cutting-edge applications. To date, extensive research activities have been performed on the investigation of diverse properties of GRP. The incorporation of this elegant material can be very lucrative in terms of practical applications in energy storage/conversion systems. Among various those systems, high performance electrochemical capacitors (ECs) have become popular due to the recent need for energy efficient and portable devices. Therefore, in this article, the application of GRP for capacitors is described succinctly. In particular, a concise summary on the previous research activities regarding GRP based capacitors is also covered extensively. It was revealed that a lot of secondary materials such as polymers and metal oxides have been introduced to improve the performance. Also, diverse devices have been combined with capacitors for better use. More importantly, recent patents related to the preparation and application of GRP based capacitors are also introduced briefly. This article can provide essential information for future study. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

SRF MATERIALS OTHER THAN NIOBIUM

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

Valente, Anne-Marie

2008-02-12

For the past three decades, bulk niobium has been the material of choice for SRF cavity applications. Alternative materials, mainly Nb compounds and A15 compounds have been investigated with moderate effort in the past. In the recent years, RF cavity performance has approached the theoretical limit for bulk niobium. For further improvement of RF cavity performance for future accelerator projects, research interest is renewed towards alternative materials to niobium. A few laboratories around the world are now investigating superconductors with higher transition temperature Tc for application to SRF cavities. This paper gives an overview of the results obtained and challengesmore » encountered for Nb compounds and A15 compounds, as well as for MgB2, for SRF cavity applications. An interesting alternative has been recently proposed by Alex Gurevich with the Superconductor-Insulator-Superconductor multilayer approach. This could potentially lead to further improvement in RF cavity performance using the benefit of the higher critical field Hc of higher-Tc superconductors without being limited with their lower Hc1.« less

Developments in metallic materials for aerospace applications

NASA Astrophysics Data System (ADS)

Wadsworth, J.; Froes, F. H.

1989-05-01

High-performance aerospace systems are creating a demand for new materials, not only for airframe and engine applications, but for missile and space systems as well. Recently, advances have been made in metallic materials systems based on magnesium, aluminum, titanium and niobium using a variety of processing methods, including ingot casting, powder metallurgy, rapid solidification and composite technology.

Mangalith: a new lithium pacemaker battery

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

Gerbier, G.; Lehmann, G.

1980-01-01

An original lithium battery system is being developed for pacemaker application. The material used, lithium-manganese dioxide, industrially available at the present time for a variety of electronic applications, has been modified and adapted for pacemaker power requirements. The utilization of a different modification of manganese dioxide offers performance advantages. The cell technology is described and performance comparisons between this new cathode material and the industrial counterpart are reported. 7 refs.

Survey of materials for hydrazine propulsion systems in multicycle extended life applications

NASA Technical Reports Server (NTRS)

Coulbert, C. D.; Yankura, G.

1972-01-01

An assessment is presented of materials compatibility data for hydrazine monopropellant propulsion systems applicable to the Space Shuttle vehicle missions. Materials were evaluated for application over a 10-yr/100-mission operational lifetime with minimum refurbishment. A general materials compatibility rating for a broad range of materials and several propellants based primarily on static liquid propellant immersion testing and an in-depth evaluation of hydrazine decomposition as a function of purity, temperature, material, surface conditions, etc., are presented. The most promising polymeric material candidates for propellant diaphragms and seals appear to have little effect on increasing hydrazine decomposition rates, but the materials themselves do undergo changes in physical properties which can affect their 10-yr performance in multicycle applications. The available data on these physical properties of elastomeric materials as affected by exposure to hydrazine or related environments are presented.

PMR polyimide composites for aerospace applications

NASA Technical Reports Server (NTRS)

Serafini, T. T.

1982-01-01

Fiber reinforced PMR polyimides are finding increased acceptance as engineering materials for high performance structural applications. Prepreg materials based on this novel class of highly processable, high temperature resistant polyimides, are commercially available and the PMR concept was incorporated in several industrial applications. The status of PMR polyimides is reviewed. Emphasis is given to the chemistry, processing, and applications of the first generation PMR polyimides known as PMR-15.

Surface modification: advantages, techniques, and applications

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

Natesan, K.

2000-03-01

Adequate performance of materials at elevated temperatures is a potential problem in many systems within the chemical, petroleum, process, and power-generating industries. Degradation of materials occurs because of interaction between the structural material and the exposure environment. These interactions are generally undesired chemical reactions that can lead to accelerated wastage and alter the functional requirements and/or structural integrity of the materials. Therefore, material selection for high-temperature applications must be based not only on a material strength properties but also on resistance to the complex environments prevalent in the anticipated exposure environment. As plants become larger, the satisfactory performance and reliabilitymore » of components play a greater role in plant availability and economics. However, system designers are becoming increasingly concerned with finding the least expensive material that will satisfactorily perform the design function for the desired service life. This present paper addresses the benefits of surface modification and identified several criteria for selection and application of modified surfaces in the power sector. A brief review is presented on potential methods for modification of surfaces, with the emphasis on coatings. In the final section of the paper, several examples address the requirements of different energy systems and surface modification avenues that have been applied to resolve the issues.« less

Jet engine applications for materials with nanometer-scale dimensions

NASA Technical Reports Server (NTRS)

Appleby, J. W., Jr.

1995-01-01

The performance of advanced military and commercial gas turbine engines is often linked to advances in materials technology. High performance gas turbine engines being developed require major material advances in strength, toughness, reduced density and improved temperature capability. The emerging technology of nanostructured materials has enormous potential for producing materials with significant improvements in these properties. Extraordinary properties demonstrated in the laboratory include material strengths approaching theoretical limit, ceramics that demonstrate ductility and toughness, and materials with ultra-high hardness. Nanostructured materials and coatings have the potential for meeting future gas turbine engine requirements for improved performance, reduced weight and lower fuel consumption.

Jet engine applications for materials with nanometer-scale dimensions

NASA Technical Reports Server (NTRS)

Appleby, J. W., Jr.

1995-01-01

The performance of advanced military and commercial gas turbine engines is often linked to advances in materials technology. High performance gas turbine engines being developed require major material advances in strength, toughness, reduced density and improved temperature capability. The emerging technology of nanostructured materials has enormous potential for producing materials with significant improvements in these properties. Extraordinary properties demonstrated in the laboratory include material strengths approaching theoretical limit, ceramics that demonstrate ductility and toughness, and material with ultra-high hardness. Nanostructured materials and coatings have the potential for meeting future gas turbine engine requirements for improved performance, reduced weight and lower fuel consumption.

Solar Concentrator Advanced Development Program, Task 1

NASA Technical Reports Server (NTRS)

1986-01-01

Solar dynamic power generation has been selected by NASA to provide power for the space station. Solar dynamic concentrator technology has been demonstrated for terrestrial applications but has not been developed for space applications. The object of the Solar Concentrator Advanced Development program is to develop the technology of solar concentrators which would be used on the space station. The first task of this program was to develop conceptual concentrator designs and perform trade-off studies and to develop a materials data base and perform material selection. Three unique concentrator concepts; Truss Hex, Spline Radial Panel and Domed Fresnel, were developed and evaluated against weighted trade criteria. The Truss Hex concept was recommended for the space station. Materials data base development demonstrated that several material systems are capable of withstanding extended periods of atomic oxygen exposure without undesirable performance degradation. Descriptions of the conceptual designs and materials test data are included.

Ferroelectric Phase Transformations for Energy Conversion and Storage Applications

NASA Astrophysics Data System (ADS)

Jo, Hwan Ryul

Ferroelectric materials possess a spontaneous polarization and actively respond to external mechanical, electrical, and thermal loads. Due to their coupled behavior, ferroelectric materials are used in products such as sensors, actuators, detectors, and transducers. However, most current applications rely on low-energy conversion that involves low magnitude fields. They utilize the low-field linear properties of ferroelectric materials (piezoelectric, pyroelectric) and do not take full advantage of the large-field nonlinear behavior (irreversible domain wall motion, phase transformations) that can occur in ferroelectric materials. When external fields exceed a certain critical level, a structural transformation of the crystal can occur. These phase transformations are accompanied by a much larger response than the linear piezoelectric and pyroelectric responses, by as much as a multiple of ten times in the magnitude. This makes the non-linear behavior in ferroelectric materials promising for energy harvesting and energy storage technologies which will benefit from large-energy conversion. Yet, the ferroelectric phase transformation behavior under large external fields have been less studied and only a few studies have been directed at utilizing this large material response in applications. This dissertation addresses the development ferroelectric phase transformation-based applications, with particular focus on the materials. Development of the ferroelectric phase transformation-based applications was approached in several steps. First, the phase transformation behavior was fully characterized and understood by measuring the phase transformation responses under mechanical, electrical, thermal, and combined loads. Once the behavior was well characterized, systems level applications were addressed. This required assessing the effect of the phase transformation behavior on system performance. The performance of ferroelectric devices is strongly dependent on material properties and phase transformation behavior which can be tailored by modifying the chemical composition, processing conditions, and the loading history (poling). This results in optimization of system performance by tailoring material properties and phase transformation behavior. This approach applied to three ferroelectric phase transformation-based applications: 1. Ferroelectric energy generation 2. Ferroelectric high-energy storage capacitor 3. Ferroelectric thermal energy harvesting. This dissertation has addressed tuning the large field properties for phase transformation-based systems.

A study of the stress wave factor technique for evaluation of composite materials

NASA Technical Reports Server (NTRS)

Duke, J. C., Jr.; Henneke, E. G., II; Kiernan, M. T.; Grosskopf, P. P.

1989-01-01

The acousto-ultrasonic approach for nondestructive evaluation provides a measurement procedure for quantifying the integrated effect of globally distributed damage characteristic of fiber reinforced composite materials. The evaluation procedure provides a stress wave factor that correlates closely with several material performance parameters. The procedure was investigated for a variety of materials including advanced composites, hybrid structure bonds, adhesive bonds, wood products, and wire rope. The research program focused primarily on development of fundamental understanding and applications advancements of acousto-ultrasonics for materials characterization. This involves characterization of materials for which detection, location, and identification of imperfections cannot at present be analyzed satisfactorily with mechanical performance prediction models. In addition to presenting definitive studies on application potentials, the understanding of the acousto-ultrasonic method as applied to advanced composites is reviewed.

Bioinspired Design: Magnetic Freeze Casting

NASA Astrophysics Data System (ADS)

Porter, Michael Martin

Nature is the ultimate experimental scientist, having billions of years of evolution to design, test, and adapt a variety of multifunctional systems for a plethora of diverse applications. Next-generation materials that draw inspiration from the structure-property-function relationships of natural biological materials have led to many high-performance structural materials with hybrid, hierarchical architectures that fit form to function. In this dissertation, a novel materials processing method, magnetic freeze casting, is introduced to develop porous scaffolds and hybrid composites with micro-architectures that emulate bone, abalone nacre, and other hard biological materials. This method uses ice as a template to form ceramic-based materials with continuously, interconnected microstructures and magnetic fields to control the alignment of these structures in multiple directions. The resulting materials have anisotropic properties with enhanced mechanical performance that have potential applications as bone implants or lightweight structural composites, among others.

Environmental Applications of Interfacial Materials with Special Wettability

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

Wang, Zhangxin; Elimelech, Menachem; Lin, Shihong

Interfacial materials with special wettability have become a burgeoning research area in materials science in the past decade. The unique surface properties of materials and interfaces generated by biomimetic approaches can be leveraged to develop effective solutions to challenging environmental problems. This critical review presents the concept, mechanisms, and fabrication techniques of interfacial materials with special wettability, and assesses the environmental applications of these materials for oil-water separation, membrane-based water purification and desalination, biofouling control, high performance vapor condensation, and atmospheric water collection. We also highlight the most promising properties of interfacial materials with special wettability that enable innovative environmentalmore » applications and discuss the practical challenges for large-scale implementation of these novel materials.« less

Environmental Applications of Interfacial Materials with Special Wettability

DOE PAGES

Wang, Zhangxin; Elimelech, Menachem; Lin, Shihong

2016-02-01

Interfacial materials with special wettability have become a burgeoning research area in materials science in the past decade. The unique surface properties of materials and interfaces generated by biomimetic approaches can be leveraged to develop effective solutions to challenging environmental problems. This critical review presents the concept, mechanisms, and fabrication techniques of interfacial materials with special wettability, and assesses the environmental applications of these materials for oil-water separation, membrane-based water purification and desalination, biofouling control, high performance vapor condensation, and atmospheric water collection. We also highlight the most promising properties of interfacial materials with special wettability that enable innovative environmentalmore » applications and discuss the practical challenges for large-scale implementation of these novel materials.« less

High-Performance Composite Chocolate

ERIC Educational Resources Information Center

Dean, Julian; Thomson, Katrin; Hollands, Lisa; Bates, Joanna; Carter, Melvyn; Freeman, Colin; Kapranos, Plato; Goodall, Russell

2013-01-01

The performance of any engineering component depends on and is limited by the properties of the material from which it is fabricated. It is crucial for engineering students to understand these material properties, interpret them and select the right material for the right application. In this paper we present a new method to engage students with…

Graphene-based smart materials

NASA Astrophysics Data System (ADS)

Yu, Xiaowen; Cheng, Huhu; Zhang, Miao; Zhao, Yang; Qu, Liangti; Shi, Gaoquan

2017-09-01

The high specific surface area and the excellent mechanical, electrical, optical and thermal properties of graphene make it an attractive component for high-performance stimuli-responsive or 'smart' materials. Complementary to these inherent properties, functionalization or hybridization can substantially improve the performance of these materials. Typical graphene-based smart materials include mechanically exfoliated perfect graphene, chemical vapour deposited high-quality graphene, chemically modified graphene (for example, graphene oxide and reduced graphene oxide) and their macroscopic assemblies or composites. These materials are sensitive to a range of stimuli, including gas molecules or biomolecules, pH value, mechanical strain, electrical field, and thermal or optical excitation. In this Review, we outline different graphene-based smart materials and their potential applications in actuators, chemical or strain sensors, self-healing materials, photothermal therapy and controlled drug delivery. We also introduce the working mechanisms of graphene-based smart materials and discuss the challenges facing the realization of their practical applications.

Quantitative description on structure-property relationships of Li-ion battery materials for high-throughput computations

NASA Astrophysics Data System (ADS)

Wang, Youwei; Zhang, Wenqing; Chen, Lidong; Shi, Siqi; Liu, Jianjun

2017-12-01

Li-ion batteries are a key technology for addressing the global challenge of clean renewable energy and environment pollution. Their contemporary applications, for portable electronic devices, electric vehicles, and large-scale power grids, stimulate the development of high-performance battery materials with high energy density, high power, good safety, and long lifetime. High-throughput calculations provide a practical strategy to discover new battery materials and optimize currently known material performances. Most cathode materials screened by the previous high-throughput calculations cannot meet the requirement of practical applications because only capacity, voltage and volume change of bulk were considered. It is important to include more structure-property relationships, such as point defects, surface and interface, doping and metal-mixture and nanosize effects, in high-throughput calculations. In this review, we established quantitative description of structure-property relationships in Li-ion battery materials by the intrinsic bulk parameters, which can be applied in future high-throughput calculations to screen Li-ion battery materials. Based on these parameterized structure-property relationships, a possible high-throughput computational screening flow path is proposed to obtain high-performance battery materials.

Quantitative description on structure-property relationships of Li-ion battery materials for high-throughput computations.

PubMed

Wang, Youwei; Zhang, Wenqing; Chen, Lidong; Shi, Siqi; Liu, Jianjun

2017-01-01

Li-ion batteries are a key technology for addressing the global challenge of clean renewable energy and environment pollution. Their contemporary applications, for portable electronic devices, electric vehicles, and large-scale power grids, stimulate the development of high-performance battery materials with high energy density, high power, good safety, and long lifetime. High-throughput calculations provide a practical strategy to discover new battery materials and optimize currently known material performances. Most cathode materials screened by the previous high-throughput calculations cannot meet the requirement of practical applications because only capacity, voltage and volume change of bulk were considered. It is important to include more structure-property relationships, such as point defects, surface and interface, doping and metal-mixture and nanosize effects, in high-throughput calculations. In this review, we established quantitative description of structure-property relationships in Li-ion battery materials by the intrinsic bulk parameters, which can be applied in future high-throughput calculations to screen Li-ion battery materials. Based on these parameterized structure-property relationships, a possible high-throughput computational screening flow path is proposed to obtain high-performance battery materials.

An automated protocol for performance benchmarking a widefield fluorescence microscope.

PubMed

Halter, Michael; Bier, Elianna; DeRose, Paul C; Cooksey, Gregory A; Choquette, Steven J; Plant, Anne L; Elliott, John T

2014-11-01

Widefield fluorescence microscopy is a highly used tool for visually assessing biological samples and for quantifying cell responses. Despite its widespread use in high content analysis and other imaging applications, few published methods exist for evaluating and benchmarking the analytical performance of a microscope. Easy-to-use benchmarking methods would facilitate the use of fluorescence imaging as a quantitative analytical tool in research applications, and would aid the determination of instrumental method validation for commercial product development applications. We describe and evaluate an automated method to characterize a fluorescence imaging system's performance by benchmarking the detection threshold, saturation, and linear dynamic range to a reference material. The benchmarking procedure is demonstrated using two different materials as the reference material, uranyl-ion-doped glass and Schott 475 GG filter glass. Both are suitable candidate reference materials that are homogeneously fluorescent and highly photostable, and the Schott 475 GG filter glass is currently commercially available. In addition to benchmarking the analytical performance, we also demonstrate that the reference materials provide for accurate day to day intensity calibration. Published 2014 Wiley Periodicals Inc. Published 2014 Wiley Periodicals Inc. This article is a US government work and, as such, is in the public domain in the United States of America.

Removal of formaldehyde from air using functionalized silica supports.

PubMed

Ewlad-Ahmed, Abdunaser M; Morris, Michael A; Patwardhan, Siddharth V; Gibson, Lorraine T

2012-12-18

This paper demonstrates the use of functionalized meso-silica materials (MCM-41 or SBA-15) as adsorbents for formaldehyde (H₂CO) vapor from contaminated air. Additionally new green nanosilica (GNs) materials were prepared via a bioinspired synthesis route and were assessed for removal of H₂CO from contaminated indoor air. These exciting new materials were prepared via rapid, 15 min, environmentally friendly synthesis routes avoiding any secondary pollution. They provided an excellent platform for functionalization and extraction of H₂CO demonstrating similar performance to the conventional meso-silica materials. To the authors' knowledge this is the first reported practical application of this material type. Prior to trapping, all materials were functionalized with amino-propyl groups which led to chemisorption of H₂CO; removing it permanently from air. No retention of H₂CO was achieved with nonfunctionalized material and it was observed that best extraction performance required a dynamic adsorption setup when compared to passive application. These results demonstrate the first application of GNs as potential adsorbents and functionalized meso-silica for use in remediation of air pollution in indoor air.

Membrane-based technologies for biogas separations.

PubMed

Basu, Subhankar; Khan, Asim L; Cano-Odena, Angels; Liu, Chunqing; Vankelecom, Ivo F J

2010-02-01

Over the past two decades, membrane processes have gained a lot of attention for the separation of gases. They have been found to be very suitable for wide scale applications owing to their reasonable cost, good selectivity and easily engineered modules. This critical review primarily focuses on the various aspects of membrane processes related to the separation of biogas, more in specific CO(2) and H(2)S removal from CH(4) and H(2) streams. Considering the limitations of inorganic materials for membranes, the present review will only focus on work done with polymeric materials. An overview on the performance of commercial membranes and lab-made membranes highlighting the problems associated with their applications will be given first. The development studies carried out to enhance the performance of membranes for gas separation will be discussed in the subsequent section. This review has been broadly divided into three sections (i) performance of commercial polymeric membranes (ii) performance of lab-made polymeric membranes and (iii) performance of mixed matrix membranes (MMMs) for gas separations. It will include structural modifications at polymer level, polymer blending, as well as synthesis of mixed matrix membranes, for which addition of silane-coupling agents and selection of suitable fillers will receive special attention. Apart from an overview of the different membrane materials, the study will also highlight the effects of different operating conditions that eventually decide the performance and longevity of membrane applications in gas separations. The discussion will be largely restricted to the studies carried out on polyimide (PI), cellulose acetate (CA), polysulfone (PSf) and polydimethyl siloxane (PDMS) membranes, as these membrane materials have been most widely used for commercial applications. Finally, the most important strategies that would ensure new commercial applications will be discussed (156 references).

Research of Flammability of Fireproof Materials in Ship Safety

NASA Astrophysics Data System (ADS)

Jiang, Yizhou; Han, Duanfeng; Zhang, Ziwei

2017-09-01

This paper analyzes the classification, performance and application of ship fireproof and heat insulating materials, and describes the test standard and performance evaluation criteria of the non-combustibility, low flame-spread characteristics and smoke and toxicity of marine fireproof materials in detail. So the paper has certain reference value and guidance significance for the selection of heat insulating materials with fire divisions and the use of flammable materials on board in accordance with requirements.

A study on the effect of surface topography on the actuation performance of stacked-rolled dielectric electro active polymer actuator

NASA Astrophysics Data System (ADS)

Sait, Usha; Muthuswamy, Sreekumar

2016-05-01

Dielectric electro active polymer (DEAP) is a suitable actuator material that finds wide applications in the field of robotics and medical areas. This material is highly controllable, flexible, and capable of developing large strain. The influence of geometrical behavior becomes critical when the material is used as miniaturized actuation devices in robotic applications. The present work focuses on the effect of surface topography on the performance of flat (single sheet) and stacked-rolled DEAP actuators. The non-active areas in the form of elliptical spots that affect the performance of the actuator are identified using scanning electron microscope (SEM) and energy dissipated X-ray (EDX) experiments. Performance of DEAP actuation is critically evaluated, compared, and presented with analytical and experimental results.

10 CFR 216.4 - Evaluation by DOE of applications.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Energy DEPARTMENT OF ENERGY OIL MATERIALS ALLOCATION AND PRIORITY PERFORMANCE UNDER CONTRACTS OR ORDERS... described supplies of materials and equipment, services, or facilities are critical and essential to the... and equipment, services, or facilities described in the application are critical and essential to an...

10 CFR 216.4 - Evaluation by DOE of applications.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Energy DEPARTMENT OF ENERGY OIL MATERIALS ALLOCATION AND PRIORITY PERFORMANCE UNDER CONTRACTS OR ORDERS... described supplies of materials and equipment, services, or facilities are critical and essential to the... and equipment, services, or facilities described in the application are critical and essential to an...

10 CFR 216.4 - Evaluation by DOE of applications.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Energy DEPARTMENT OF ENERGY OIL MATERIALS ALLOCATION AND PRIORITY PERFORMANCE UNDER CONTRACTS OR ORDERS... described supplies of materials and equipment, services, or facilities are critical and essential to the... and equipment, services, or facilities described in the application are critical and essential to an...

10 CFR 216.4 - Evaluation by DOE of applications.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Energy DEPARTMENT OF ENERGY OIL MATERIALS ALLOCATION AND PRIORITY PERFORMANCE UNDER CONTRACTS OR ORDERS... described supplies of materials and equipment, services, or facilities are critical and essential to the... and equipment, services, or facilities described in the application are critical and essential to an...

10 CFR 216.4 - Evaluation by DOE of applications.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Energy DEPARTMENT OF ENERGY OIL MATERIALS ALLOCATION AND PRIORITY PERFORMANCE UNDER CONTRACTS OR ORDERS... described supplies of materials and equipment, services, or facilities are critical and essential to the... and equipment, services, or facilities described in the application are critical and essential to an...

Current status and recent research achievements in SiC/SiC composites

NASA Astrophysics Data System (ADS)

Katoh, Y.; Snead, L. L.; Henager, C. H.; Nozawa, T.; Hinoki, T.; Iveković, A.; Novak, S.; Gonzalez de Vicente, S. M.

2014-12-01

The silicon carbide fiber-reinforced silicon carbide matrix (SiC/SiC) composite system for fusion applications has seen a continual evolution from development a fundamental understanding of the material system and its behavior in a hostile irradiation environment to the current effort which is directed at a broad-based program of technology maturation program. In essence, over the past few decades this material system has steadily moved from a laboratory curiosity to an engineering material, both for fusion structural applications and other high performance application such as aerospace. This paper outlines the recent international scientific and technological achievements towards the development of SiC/SiC composite material technologies for fusion application and discusses future research directions. It also reviews the materials system in the larger context of progress to maturity as an engineering material for both the larger nuclear community and broader engineering applications.

Electrically tunable materials for microwave applications

NASA Astrophysics Data System (ADS)

Ahmed, Aftab; Goldthorpe, Irene A.; Khandani, Amir K.

2015-03-01

Microwave devices based on tunable materials are of vigorous current interest. Typical applications include phase shifters, antenna beam steering, filters, voltage controlled oscillators, matching networks, and tunable power splitters. The objective of this review is to assist in the material selection process for various applications in the microwave regime considering response time, required level of tunability, operating temperature, and loss tangent. The performance of a variety of material types are compared, including ferroelectric ceramics, polymers, and liquid crystals. Particular attention is given to ferroelectric materials as they are the most promising candidates when response time, dielectric loss, and tunability are important. However, polymers and liquid crystals are emerging as potential candidates for a number of new applications, offering mechanical flexibility, lower weight, and lower tuning voltages.

Three-Dimensional, Inelastic Response of Single-Edge Notch Bend Specimens Subjected to Impact Loading

DTIC Science & Technology

1993-08-01

measure the inherent fracture toughness of a material. A thor- ough understanding of the test specimen behavior is a prerequisite to the application of...measured material properties in structural applications . Three- dimensional dynamic analyses are performed for three different specimen configurations...derstanding of the test specimen behavior is a prerequisite to the application of measured ma- terial properties in structural applications . Three

Application of Ni-Oxide@TiO2 Core-Shell Structures to Photocatalytic Mixed Dye Degradation, CO Oxidation, and Supercapacitors

PubMed Central

Lee, Seungwon; Lee, Jisuk; Nam, Kyusuk; Shin, Weon Gyu; Sohn, Youngku

2016-01-01

Performing diverse application tests on synthesized metal oxides is critical for identifying suitable application areas based on the material performances. In the present study, Ni-oxide@TiO2 core-shell materials were synthesized and applied to photocatalytic mixed dye (methyl orange + rhodamine + methylene blue) degradation under ultraviolet (UV) and visible lights, CO oxidation, and supercapacitors. Their physicochemical properties were examined by field-emission scanning electron microscopy, X-ray diffraction analysis, Fourier-transform infrared spectroscopy, and UV-visible absorption spectroscopy. It was shown that their performances were highly dependent on the morphology, thermal treatment procedure, and TiO2 overlayer coating. PMID:28774145

A HUMAN RELIABILITY-CENTERED APPROACH TO THE DEVELOPMENT OF JOB AIDS FOR REVIEWERS OF MEDICAL DEVICES THAT USE RADIOLOGICAL BYPRODUCT MATERIALS.

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

COOPER, S.E.; BROWN, W.S.; WREATHALL, J.

2005-02-02

The U.S. Nuclear Regulatory Commission (NRC) is engaged in an initiative to risk-inform the regulation of byproduct materials. Operating experience indicates that human actions play a dominant role in most of the activities involving byproduct materials, which are radioactive materials other than those used in nuclear power plants or in weapons production, primarily for medical or industrial purposes. The overall risk of these activities is strongly influenced by human performance. Hence, an improved understanding of human error, its causes and contexts, and human reliability analysis (HRA) is important in risk-informing the regulation of these activities. The development of the humanmore » performance job aids was undertaken by stages, with frequent interaction with the prospective users. First, potentially risk significant human actions were identified based on reviews of available risk studies for byproduct material applications and of descriptions of events for byproduct materials applications that involved potentially significant human actions. Applications from the medical and the industrial domains were sampled. Next, the specific needs of the expected users of the human performance-related capabilities were determined. To do this, NRC headquarters and region staff were interviewed to identify the types of activities (e.g., license reviews, inspections, event assessments) that need HRA support and the form in which such support might best be offered. Because the range of byproduct uses regulated by NRC is so broad, it was decided that initial development of knowledge and tools would be undertaken in the context of a specific use of byproduct material, which was selected in consultation with NRC staff. Based on needs of NRC staff and the human performance related characteristics of the context chosen, knowledge resources were then compiled to support consideration of human performance issues related to the regulation of byproduct materials. Finally, with information sources and an application context identified, a set of strawman job aids was developed, which was then presented to prospective users for critique and comment. Work is currently under way to develop training materials and refine the job aids in preparation for a pilot evaluation.« less

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

Carter, E.

A new class of grout material based on molten wax offers a dramatic improvement in permeation grouting performance. This new material makes a perfect in situ containment of buried radioactive waste both feasible and cost effective. This paper describes various ways the material can be used to isolate buried waste in situ. Potential applications described in the paper include buried radioactive waste in deep trenches, deep shafts, Infiltration trenches, and large buried objects. Use of molten wax for retrieval of waste is also discussed. Wax can also be used for retrieval of air sensitive materials or drummed waste. This papermore » provides an analysis of the methods of application and the expected performance and cost of several potential projects. (authors)« less

Facile synthesis of ZnCo2O4/rGO nanocomposite for effective supercapacitor application

NASA Astrophysics Data System (ADS)

Mary, A. Juliet Christina; Bose, A. Chandra

2017-05-01

ZnCo2O4/rGO nanocompoite material gives the high specific capacitance value of 704.2 F/g at a current density of 0.75 A/g. rGO material provides the effective surface area for the composite which leads to better performance for supercapacitor application. Stability of ZnCo2O4/rGO nanocomposite was tested up to 400 cycles. ZnCo2O4/rGO nanocomposite is the suitable material for supercapacitor application.

Nonlinear Constitutive Relations for High Temperature Applications, 1986

NASA Technical Reports Server (NTRS)

1988-01-01

The purpose of the symposium was to review the state-of-the-art in nonlinear constitutive modeling of high temperature materials for aeronautics applications and to identify the need for future research and development efforts in this area. Through this symposium, it was recognized that considerable research efforts are urgently needed in the development of nonlinear constitutive relations for high temperature applications. In the aerospace industry this need is further prompted by recent advances in high temperature materials technology and new demands on material and component performance.

Binder-free cobalt phosphate one-dimensional nanograsses as ultrahigh-performance cathode material for hybrid supercapacitor applications

NASA Astrophysics Data System (ADS)

Sankar, K. Vijaya; Lee, S. C.; Seo, Y.; Ray, C.; Liu, S.; Kundu, A.; Jun, S. C.

2018-01-01

One-dimensional (1D) nanostructure exhibits excellent electrochemical performance because of their unique physico-chemical properties like fast electron transfer, good rate capability, and cyclic stability. In the present study, Co3(PO4)2 1D nanograsses are grown on Ni foam using a simple and eco-friendly hydrothermal technique with different reaction times. The open space with uniform nanograsses displays a high areal capacitance, rate capability, energy density, and cyclic stability due to the nanostructure enhancing fast ion and material interactions. Ex-situ microscope images confirm the dependence of structural stability on the reaction time, and the nanograsses promoted ion interaction through material. Further, the reproducibility of the electrochemical performance confirms the binder-free Co3(PO4)2 1D nanograsses to be a suitable high-performance cathode material for application to hybrid supercapacitor. Finally, the assembled hybrid supercapacitor exhibits a high energy density (26.66 Wh kg-1 at 750 W kg-1) and longer lifetimes (80% retained capacitance after 6000 cycles). Our results suggests that the Co3(PO4)2 1D nanograss design have a great promise for application to hybrid supercapacitor.

Materials for engine applications above 3000 deg F: An overview

NASA Technical Reports Server (NTRS)

Shaw, Nancy J.; Dicarlo, James A.; Jacobson, Nathan S.; Levine, Stanley R.; Nesbitt, James A.; Probst, Hubert B.; Sanders, William A.; Stearns, Carl A.

1987-01-01

Materials for future generations of aeropropulsion systems will be required to perform at ever-increasing temperatures and have properties superior to the current state of the art. Improved engine efficiency can reduce specific fuel consumption and thus increase range and reduce operating costs. The ultimate payoff gain is expected to come when materials are developed which can perform without cooling at gas temperatures to 2200 C (4000 F). An overview is presented of materials for applications above 1650 C (3000 F), some pertinent physical property data, and the rationale used: (1) to arrive at recommendations of material systems that qualify for further investigation, and (2) to develop a proposed plan of research. From an analysis of available thermochemical data it was included that such materials systems must be composed of oxide ceramics. The required structural integrity will be achieved by developing these materials into fiber-reinforced ceramic composites.

Advanced Plasmonic Materials for Dynamic Color Display.

PubMed

Shao, Lei; Zhuo, Xiaolu; Wang, Jianfang

2018-04-01

Plasmonic structures exhibit promising applications in high-resolution and durable color generation. Research on advanced hybrid plasmonic materials that allow dynamically reconfigurable color control has developed rapidly in recent years. Some of these results may give rise to practically applicable reflective displays in living colors with high performance and low power consumption. They will attract broad interest from display markets, compared with static plasmonic color printing, for example, in applications such as digital signage, full-color electronic paper, and electronic device screens. In this progress report, the most promising recent examples of utilizing advanced plasmonic materials for the realization of dynamic color display are highlighted and put into perspective. The performances, advantages, and disadvantages of different technologies are discussed, with emphasis placed on both the potential and possible limitations of various hybrid materials for dynamic plasmonic color display. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Facile and gram-scale synthesis of metal-free catalysts: toward realistic applications for fuel cells.

PubMed

Kim, Ok-Hee; Cho, Yong-Hun; Chung, Dong Young; Kim, Min Jeong; Yoo, Ji Mun; Park, Ji Eun; Choe, Heeman; Sung, Yung-Eun

2015-03-02

Although numerous reports on nonprecious metal catalysts for replacing expensive Pt-based catalysts have been published, few of these studies have demonstrated their practical application in fuel cells. In this work, we report graphitic carbon nitride and carbon nanofiber hybrid materials synthesized by a facile and gram-scale method via liquid-based reactions, without the use of toxic materials or a high pressure-high temperature reactor, for use as fuel cell cathodes. The resulting materials exhibited remarkable methanol tolerance, selectivity, and stability even without a metal dopant. Furthermore, these completely metal-free catalysts exhibited outstanding performance as cathode materials in an actual fuel cell device: a membrane electrode assembly with both acidic and alkaline polymer electrolytes. The fabrication method and remarkable performance of the single cell produced in this study represent progressive steps toward the realistic application of metal-free cathode electrocatalysts in fuel cells.

Facile and Gram-scale Synthesis of Metal-free Catalysts: Toward Realistic Applications for Fuel Cells

PubMed Central

Kim, Ok-Hee; Cho, Yong-Hun; Chung, Dong Young; Kim, Min Jeong; Yoo, Ji Mun; Park, Ji Eun; Choe, Heeman; Sung, Yung-Eun

2015-01-01

Although numerous reports on nonprecious metal catalysts for replacing expensive Pt-based catalysts have been published, few of these studies have demonstrated their practical application in fuel cells. In this work, we report graphitic carbon nitride and carbon nanofiber hybrid materials synthesized by a facile and gram-scale method via liquid-based reactions, without the use of toxic materials or a high pressure-high temperature reactor, for use as fuel cell cathodes. The resulting materials exhibited remarkable methanol tolerance, selectivity, and stability even without a metal dopant. Furthermore, these completely metal-free catalysts exhibited outstanding performance as cathode materials in an actual fuel cell device: a membrane electrode assembly with both acidic and alkaline polymer electrolytes. The fabrication method and remarkable performance of the single cell produced in this study represent progressive steps toward the realistic application of metal-free cathode electrocatalysts in fuel cells. PMID:25728910

Material characterization of active fiber composites for integral twist-actuated rotor blade application

NASA Astrophysics Data System (ADS)

Wickramasinghe, Viresh K.; Hagood, Nesbitt W.

2004-10-01

The primary objective of this work was to perform material characterization of the active fiber composite (AFC) actuator system for the Boeing active material rotor (AMR) blade application. The purpose of the AMR was to demonstrate active vibration control in helicopters through integral twist-actuation of the blade. The AFCs were a new structural actuator system consisting of piezoceramic fibers embedded in an epoxy matrix and sandwiched between interdigitated electrodes to enhance actuation performance. These conformable actuators were integrated directly into the blade spar laminate as active plies within the composite structure to perform structural control. Therefore, extensive electromechanical material characterization was required to evaluate AFCs both as actuators and as structural components of the blade. The characterization tests designed to extract important electromechanical properties under simulated blade operating conditions included nominal actuation tests, stress-strain tests and actuation under tensile load tests. This paper presents the test results as well as the comprehensive testing procedure developed to evaluate the relevant properties of the AFCs for structural application. The material characterization tests provided an invaluable insight into the behavior of the AFCs under various electromechanical conditions. The results from this comprehensive material characterization of the AFC actuator system supported the design and operation of the AMR blades scheduled for wind tunnel tests.

Nanocomposites for Machining Tools

PubMed Central

Loginov, Pavel; Mishnaevsky, Leon; Levashov, Evgeny

2017-01-01

Machining tools are used in many areas of production. To a considerable extent, the performance characteristics of the tools determine the quality and cost of obtained products. The main materials used for producing machining tools are steel, cemented carbides, ceramics and superhard materials. A promising way to improve the performance characteristics of these materials is to design new nanocomposites based on them. The application of micromechanical modeling during the elaboration of composite materials for machining tools can reduce the financial and time costs for development of new tools, with enhanced performance. This article reviews the main groups of nanocomposites for machining tools and their performance. PMID:29027926

Functional mesoporous materials for energy applications: solar cells, fuel cells, and batteries

NASA Astrophysics Data System (ADS)

Ye, Youngjin; Jo, Changshin; Jeong, Inyoung; Lee, Jinwoo

2013-05-01

This feature article presents recent progress made in the synthesis of functional ordered mesoporous materials and their application as high performance electrodes in dye-sensitized solar cells (DSCs) and quantum dot-sensitized solar cells (QDSCs), fuel cells, and Li-ion batteries. Ordered mesoporous materials have been mainly synthesized using two representative synthetic methods: the soft template and hard template methods. To overcome the limitations of these two methods, a new method called CASH was suggested. The CASH method combines the advantages of the soft and hard template methods by employing a diblock copolymer, PI-b-PEO, which contains a hydrophilic block and an sp2-hybridized-carbon-containing hydrophobic block as a structure-directing agent. After discussing general techniques used in the synthesis of mesoporous materials, this article presents recent applications of mesoporous materials as electrodes in DSCs and QDSCs, fuel cells, and Li-ion batteries. The role of material properties and mesostructures in device performance is discussed in each case. The developed soft and hard template methods, along with the CASH method, allow control of the pore size, wall composition, and pore structure, providing insight into material design and optimization for better electrode performances in these types of energy conversion devices. This paper concludes with an outlook on future research directions to enable breakthroughs and overcome current limitations in this field.

Functional mesoporous materials for energy applications: solar cells, fuel cells, and batteries.

PubMed

Ye, Youngjin; Jo, Changshin; Jeong, Inyoung; Lee, Jinwoo

2013-06-07

This feature article presents recent progress made in the synthesis of functional ordered mesoporous materials and their application as high performance electrodes in dye-sensitized solar cells (DSCs) and quantum dot-sensitized solar cells (QDSCs), fuel cells, and Li-ion batteries. Ordered mesoporous materials have been mainly synthesized using two representative synthetic methods: the soft template and hard template methods. To overcome the limitations of these two methods, a new method called CASH was suggested. The CASH method combines the advantages of the soft and hard template methods by employing a diblock copolymer, PI-b-PEO, which contains a hydrophilic block and an sp(2)-hybridized-carbon-containing hydrophobic block as a structure-directing agent. After discussing general techniques used in the synthesis of mesoporous materials, this article presents recent applications of mesoporous materials as electrodes in DSCs and QDSCs, fuel cells, and Li-ion batteries. The role of material properties and mesostructures in device performance is discussed in each case. The developed soft and hard template methods, along with the CASH method, allow control of the pore size, wall composition, and pore structure, providing insight into material design and optimization for better electrode performances in these types of energy conversion devices. This paper concludes with an outlook on future research directions to enable breakthroughs and overcome current limitations in this field.

Magnetic suspension options for spacecraft inertia-wheel applications

NASA Technical Reports Server (NTRS)

Downer, J. R.

1984-01-01

Design criteria for spacecraft inertia-wheel suspensions are listed. The advantages of magnetic suspensions over other suspension types for spacecraft inertia-wheel applications are cited along with the functions performed by magnetic suspension. The common designs for magnetic suspensions are enumerated. Materials selection of permanent magnets and core materials is considered.

NASA technology utilization survey on composite materials

NASA Technical Reports Server (NTRS)

Leeds, M. A.; Schwartz, S.; Holm, G. J.; Krainess, A. M.; Wykes, D. M.; Delzell, M. T.; Veazie, W. H., Jr.

1972-01-01

NASA and NASA-funded contractor contributions to the field of composite materials are surveyed. Existing and potential non-aerospace applications of the newer composite materials are emphasized. Economic factors for selection of a composite for a particular application are weight savings, performance (high strength, high elastic modulus, low coefficient of expansion, heat resistance, corrosion resistance,), longer service life, and reduced maintenance. Applications for composites in agriculture, chemical and petrochemical industries, construction, consumer goods, machinery, power generation and distribution, transportation, biomedicine, and safety are presented. With the continuing trend toward further cost reductions, composites warrant consideration in a wide range of non-aerospace applications. Composite materials discussed include filamentary reinforced materials, laminates, multiphase alloys, solid multiphase lubricants, and multiphase ceramics. New processes developed to aid in fabrication of composites are given.

Electrically tunable materials for microwave applications

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

Ahmed, Aftab, E-mail: aahmed@anl.gov; Goldthorpe, Irene A.; Khandani, Amir K.

2015-03-15

Microwave devices based on tunable materials are of vigorous current interest. Typical applications include phase shifters, antenna beam steering, filters, voltage controlled oscillators, matching networks, and tunable power splitters. The objective of this review is to assist in the material selection process for various applications in the microwave regime considering response time, required level of tunability, operating temperature, and loss tangent. The performance of a variety of material types are compared, including ferroelectric ceramics, polymers, and liquid crystals. Particular attention is given to ferroelectric materials as they are the most promising candidates when response time, dielectric loss, and tunability aremore » important. However, polymers and liquid crystals are emerging as potential candidates for a number of new applications, offering mechanical flexibility, lower weight, and lower tuning voltages.« less

Performance prediction evaluation of ceramic materials in point-focusing solar receivers

NASA Technical Reports Server (NTRS)

Ewing, J.; Zwissler, J.

1979-01-01

A performance prediction was adapted to evaluate the use of ceramic materials in solar receivers for point focusing distributed applications. System requirements were determined including the receiver operating environment and system operating parameters for various engine types. Preliminary receiver designs were evolved from these system requirements. Specific receiver designs were then evaluated to determine material functional requirements.

Polymeric Materials for Aerospace Power and Propulsion-NASA Glenn Overview

NASA Technical Reports Server (NTRS)

Meador, Michael A.

2008-01-01

Use of lightweight materials in aerospace power and propulsion components can lead to significant reductions in vehicle weight and improvements in performance and efficiency. Polymeric materials are well suited for many of these applications, but improvements in processability, durability and performance are required for their successful use in these components. Polymers Research at NASA Glenn is focused on utilizing a combination of traditional polymer science and engineering approaches and nanotechnology to develop new materials with enhanced processability, performance and durability. An overview of these efforts will be presented.

The Effects of Doping and Processing on the Thermoelectric Properties of Platinum Diantimonide Based Materials for Cryogenic Peltier Cooling Applications

NASA Astrophysics Data System (ADS)

Waldrop, Spencer Laine

The study of thermoelectrics is nearly two centuries old. In that time a large number of applications have been discovered for these materials which are capable of transforming thermal energy into electricity or using electrical work to create a thermal gradient. Current use of thermoelectric materials is in very niche applications with contemporary focus being upon their capability to recover waste heat. A relatively undeveloped region for thermoelectric application is focused upon Peltier cooling at low temperatures. Materials based on bismuth telluride semiconductors have been the gold standard for close to room temperature applications for over sixty years. For applications below room temperature, semiconductors based on bismuth antimony reign supreme with few other possible materials. The cause of this diculty in developing new, higher performing materials is due to the interplay of the thermoelectric properties of these materials. The Seebeck coecient, which characterizes the phenomenon of the conversion of heat to electricity, the electrical conductivity, and the thermal conductivity are all interconnected properties of a material which must be optimized to generate a high performance thermoelectric material. While for above room temperature applications many advancements have been made in the creation of highly ecient thermoelectric materials, the below room temperature regime has been stymied by ill-suited properties, low operating temperatures, and a lack of research. The focus of this work has been to investigate and optimize the thermoelectric properties of platinum diantimonide, PtSb2, a nearly zero gap semiconductor. The electronic properties of PtSb2 are very favorable for cryogenic Peltier applications, as it exhibits good conductivity and large Seebeck coecient below 200 K. It is shown that both n- and p-type doping may be applied to this compound to further improve its electronic properties. Through both solid solution formation and processing techniques, the thermal conductivity may be reduced in order to increase the thermoelectric gure of merit. Further reduction in thermal conductivity using other novel approaches is identied as an area of promising future research. Continued development of this material has the potential to generate a suitable replacement for some low temperature applications, but will certainly further scientic knowledge and understanding of the optimization of thermoelectric materials in this temperature regime.

Discovery of high-performance low-cost n-type Mg3Sb2-based thermoelectric materials with multi-valley conduction bands

PubMed Central

Zhang, Jiawei; Song, Lirong; Pedersen, Steffen Hindborg; Yin, Hao; Hung, Le Thanh; Iversen, Bo Brummerstedt

2017-01-01

Widespread application of thermoelectric devices for waste heat recovery requires low-cost high-performance materials. The currently available n-type thermoelectric materials are limited either by their low efficiencies or by being based on expensive, scarce or toxic elements. Here we report a low-cost n-type material, Te-doped Mg3Sb1.5Bi0.5, that exhibits a very high figure of merit zT ranging from 0.56 to 1.65 at 300−725 K. Using combined theoretical prediction and experimental validation, we show that the high thermoelectric performance originates from the significantly enhanced power factor because of the multi-valley band behaviour dominated by a unique near-edge conduction band with a sixfold valley degeneracy. This makes Te-doped Mg3Sb1.5Bi0.5 a promising candidate for the low- and intermediate-temperature thermoelectric applications. PMID:28059069

Basic principles for rational design of high-performance nanostructured silicon-based thermoelectric materials.

PubMed

Yang, Chun Cheng; Li, Sean

2011-12-23

Recently, nanostructured silicon-based thermoelectric materials have drawn great attention owing to their excellent thermoelectric performance in the temperature range around 450 °C, which is eminently applicable for concentrated solar thermal technology. In this work, a unified nanothermodynamic model is developed to investigate the predominant factors that determine the lattice thermal conductivity of nanocrystalline, nanoporous, and nanostructured bulk Si. A systematic study shows that the thermoelectric performance of these materials can be substantially enhanced by the following three basic principles: 1) artificial manipulation and optimization of roughness with surface/interface patterning/engineering; 2) grain-size reduction with innovative fabrication techniques in a controllable fashion; and 3) optimization of material parameters, such as bulk solid-vapor transition entropy, bulk vibrational entropy, dimensionality, and porosity, to decrease the lattice thermal conductivity. These principles may be used to rationally design novel nanostructured Si-based thermoelectric materials for renewable energy applications. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Comparative investigation of compressive resistance of glass-cermet cements used as a core material in post-core systems].

PubMed

Ersoy, E; Cetiner, S; Koçak, F

1989-09-01

In post-core applications, addition to the cast designs restorations that are performed on fabrication posts with restorative materials are being used. To improve the physical properties of glass-ionomer cements that are popular today, glass-cermet cements have been introduced and those materials have been proposed to be an alternative restorative material in post-core applications. In this study, the compressive resistance of Ketac-Silver as a core material was investigated comparatively with amalgam and composite resins.

Quantitative description on structure–property relationships of Li-ion battery materials for high-throughput computations

PubMed Central

Wang, Youwei; Zhang, Wenqing; Chen, Lidong; Shi, Siqi; Liu, Jianjun

2017-01-01

Abstract Li-ion batteries are a key technology for addressing the global challenge of clean renewable energy and environment pollution. Their contemporary applications, for portable electronic devices, electric vehicles, and large-scale power grids, stimulate the development of high-performance battery materials with high energy density, high power, good safety, and long lifetime. High-throughput calculations provide a practical strategy to discover new battery materials and optimize currently known material performances. Most cathode materials screened by the previous high-throughput calculations cannot meet the requirement of practical applications because only capacity, voltage and volume change of bulk were considered. It is important to include more structure–property relationships, such as point defects, surface and interface, doping and metal-mixture and nanosize effects, in high-throughput calculations. In this review, we established quantitative description of structure–property relationships in Li-ion battery materials by the intrinsic bulk parameters, which can be applied in future high-throughput calculations to screen Li-ion battery materials. Based on these parameterized structure–property relationships, a possible high-throughput computational screening flow path is proposed to obtain high-performance battery materials. PMID:28458737

Evaluation of alternative phase change materials for energy storage in solar dynamic applications

NASA Technical Reports Server (NTRS)

Crane, R. A.; Dustin, M. O.

1988-01-01

The performance of fluoride salt and metallic thermal energy storage materials are compared in terms of basic performance as applied to solar dynamic power generation. Specific performance considerations include uniformity of cycle inlet temperature, peak cavity temperature, TES utilization, and system weights. Also investigated were means of enhancing the thermal conductivity of the salts and its effect on the system performance.

Photonics and plasmonics go viral: self-assembly of hierarchical metamaterials

DOE PAGES

Wen, Amy M.; Podgornik, Rudolf; Strangi, Giuseppe; ...

2015-03-05

Sizing and shaping of mesoscale architectures with nanoscale features is a key opportunity to produce the next generation of higher-performing products and at the same time unveil completely new phenomena. This review article discusses recent advances in the design of novel photonic and plasmonic structures using a biology-inspired design. The proteinaceous capsids from viruses have long been discovered as platform technologies enabling unique applications in nanotechnology, materials, bioengineering, and medicine. In the context of materials applications, the highly organized structures formed by viral capsid proteins provide a 3D scaffold for the precise placement of plasmon and gain materials. Based onmore » their highly symmetrical structures, virus-based nanoparticles have a high propensity to self-assemble into higher-order crystalline structures, yielding hierarchical hybrid materials. Recent advances in the field have led to the development of virus-based light harvesting systems, plasmonic structures for application in high-performance metamaterials, binary nanoparticle lattices, and liquid crystalline arrays for sensing or display technologies. In conclusion, there is still much that could be explored in this area, and we foresee that this is only the beginning of great technological advances in virus-based materials for plasmonics and photonics applications.« less

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

Wen, Amy M.; Podgornik, Rudolf; Strangi, Giuseppe

Sizing and shaping of mesoscale architectures with nanoscale features is a key opportunity to produce the next generation of higher-performing products and at the same time unveil completely new phenomena. This review article discusses recent advances in the design of novel photonic and plasmonic structures using a biology-inspired design. The proteinaceous capsids from viruses have long been discovered as platform technologies enabling unique applications in nanotechnology, materials, bioengineering, and medicine. In the context of materials applications, the highly organized structures formed by viral capsid proteins provide a 3D scaffold for the precise placement of plasmon and gain materials. Based onmore » their highly symmetrical structures, virus-based nanoparticles have a high propensity to self-assemble into higher-order crystalline structures, yielding hierarchical hybrid materials. Recent advances in the field have led to the development of virus-based light harvesting systems, plasmonic structures for application in high-performance metamaterials, binary nanoparticle lattices, and liquid crystalline arrays for sensing or display technologies. In conclusion, there is still much that could be explored in this area, and we foresee that this is only the beginning of great technological advances in virus-based materials for plasmonics and photonics applications.« less

Practical Applications of Math and Science in Junior High Schools

DTIC Science & Technology

1984-04-01

APPLICATIONS OF MATH AND SCIENCE IN JUNIOR HIGH SCHOOLS AUTHOR(S) MAJOR LAWRENCE N. HYLAND, USAF FACULTY ADVISOR mAJoR JAMM WILSON, ACSC/EDDP SPONSOR LT COL...JUNIOR HIGH SCHOOLS 6 PERFORMING O1G. REPORT NUMBER "ś, Au THORrs) 8. CON’RACT OR GRANT NUMBER(.,) Lawrence N. Hyland, Major, USAF 9. PERFORMING...materials aimed at the jumior high school level. Material exposes target group to the mathematical and scientific skills required of Air Force

PMR polyimides-review and update

NASA Technical Reports Server (NTRS)

Serafini, T. T.; Delvigs, P.; Alston, W. B.

1982-01-01

Fiber reinforced PMR polyimides are finding increased acceptance as engineering materials for high performance structural applications. Prepreg materials based on this novel class of highly processable, high temperature resistant polyimides are commercially available and the PMR concept is used by other investigators. The current status of first and second generation PMR polyimides were reviewed. Emphasis is given to the chemistry, processing and applications of the first generation material known as PMR-15.

Multi-Scale Microstructural Thermoelectric Materials: Transport Behavior, Non-Equilibrium Preparation, and Applications.

PubMed

Su, Xianli; Wei, Ping; Li, Han; Liu, Wei; Yan, Yonggao; Li, Peng; Su, Chuqi; Xie, Changjun; Zhao, Wenyu; Zhai, Pengcheng; Zhang, Qingjie; Tang, Xinfeng; Uher, Ctirad

2017-05-01

Considering only about one third of the world's energy consumption is effectively utilized for functional uses, and the remaining is dissipated as waste heat, thermoelectric (TE) materials, which offer a direct and clean thermal-to-electric conversion pathway, have generated a tremendous worldwide interest. The last two decades have witnessed a remarkable development in TE materials. This Review summarizes the efforts devoted to the study of non-equilibrium synthesis of TE materials with multi-scale structures, their transport behavior, and areas of applications. Studies that work towards the ultimate goal of developing highly efficient TE materials possessing multi-scale architectures are highlighted, encompassing the optimization of TE performance via engineering the structures with different dimensional aspects spanning from the atomic and molecular scales, to nanometer sizes, and to the mesoscale. In consideration of the practical applications of high-performance TE materials, the non-equilibrium approaches offer a fast and controllable fabrication of multi-scale microstructures, and their scale up to industrial-size manufacturing is emphasized here. Finally, the design of two integrated power generating TE systems are described-a solar thermoelectric-photovoltaic hybrid system and a vehicle waste heat harvesting system-that represent perhaps the most important applications of thermoelectricity in the energy conversion area. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Exploring long-wave infrared transmitting materials with AxBy form: First-principles gene-like studies.

PubMed

Du, Jia-Ren; Chen, Nian-Ke; Li, Xian-Bin; Xie, Sheng-Yi; Tian, Wei Quan; Wang, Xian-Yin; Tu, Hai-Ling; Sun, Hong-Bo

2016-02-23

Long-wave infrared (8-12 μm) transmitting materials play critical roles in space science and electronic science. However, the paradox between their mechanical strength and infrared transmitting performance seriously prohibits their applications in harsh external environment. From the experimental view, searching a good window material compatible with both properties is a vast trail-and-error engineering project, which is not readily achieved efficiently. In this work, we propose a very simple and efficient method to explore potential infrared window materials with suitable mechanical property by first-principles gene-like searching. Two hundred and fifty-three potential materials are evaluated to find their bulk modulus (for mechanical performance) and phonon vibrational frequency (for optical performance). Seven new potential candidates are selected, namely TiSe, TiS, MgS, CdF2, HgF2, CdO, and SrO. Especially, the performances of TiS and CdF2 can be comparable to that of the most popular commercial ZnS at high temperature. Finally, we propose possible ranges of infrared transmission for halogen, chalcogen and nitrogen compounds respectively to guide further exploration. The present strategy to explore IR window materials can significantly speed up the new development progress. The same idea can be used for other material rapid searching towards special functions and applications.

Lead‐Free Hybrid Perovskite Absorbers for Viable Application: Can We Eat the Cake and Have It too?

PubMed Central

Liang, Lusheng

2017-01-01

Abstract Many years since the booming of research on perovskite solar cells (PSCs), the hybrid perovskite materials developed for photovoltaic application form three main categories since 2009: (i) high‐performance unstable lead‐containing perovskites, (ii) low‐performance lead‐free perovskites, and (iii) moderate performance and stable lead‐containing perovskites. The search for alternative materials to replace lead leads to the second group of perovskite materials. To date, a number of these compounds have been synthesized and applied in photovoltaic devices. Here, lead‐free hybrid light absorbers used in PV devices are focused and their recent developments in related solar cell applications are reviewed comprehensively. In the first part, group 14 metals (Sn and Ge)‐based perovskites are introduced with more emphasis on the optimization of Sn‐based PSCs. Then concerns on halide hybrids of group 15 metals (Bi and Sb) are raised, which are mainly perovskite derivatives. At the same time, transition metal Cu‐based perovskites are also referred. In the end, an outlook is given on the design strategy of lead‐free halide hybrid absorbers for photovoltaic applications. It is believed that this timely review can represent our unique view of the field and shed some light on the direction of development of such promising materials. PMID:29610719

Lead-Free Hybrid Perovskite Absorbers for Viable Application: Can We Eat the Cake and Have It too?

PubMed

Liang, Lusheng; Gao, Peng

2018-02-01

Many years since the booming of research on perovskite solar cells (PSCs), the hybrid perovskite materials developed for photovoltaic application form three main categories since 2009: (i) high-performance unstable lead-containing perovskites, (ii) low-performance lead-free perovskites, and (iii) moderate performance and stable lead-containing perovskites. The search for alternative materials to replace lead leads to the second group of perovskite materials. To date, a number of these compounds have been synthesized and applied in photovoltaic devices. Here, lead-free hybrid light absorbers used in PV devices are focused and their recent developments in related solar cell applications are reviewed comprehensively. In the first part, group 14 metals (Sn and Ge)-based perovskites are introduced with more emphasis on the optimization of Sn-based PSCs. Then concerns on halide hybrids of group 15 metals (Bi and Sb) are raised, which are mainly perovskite derivatives. At the same time, transition metal Cu-based perovskites are also referred. In the end, an outlook is given on the design strategy of lead-free halide hybrid absorbers for photovoltaic applications. It is believed that this timely review can represent our unique view of the field and shed some light on the direction of development of such promising materials.

Triarylborane-Based Materials for OLED Applications.

PubMed

Turkoglu, Gulsen; Cinar, M Emin; Ozturk, Turan

2017-09-13

Multidisciplinary research on organic fluorescent molecules has been attracting great interest owing to their potential applications in biomedical and material sciences. In recent years, electron deficient systems have been increasingly incorporated into fluorescent materials. Triarylboranes with the empty p orbital of their boron centres are electron deficient and can be used as strong electron acceptors in conjugated organic fluorescent materials. Moreover, their applications in optoelectronic devices, energy harvesting materials and anion sensing, due to their natural Lewis acidity and remarkable solid-state fluorescence properties, have also been investigated. Furthermore, fluorescent triarylborane-based materials have been commonly utilized as emitters and electron transporters in organic light emitting diode (OLED) applications. In this review, triarylborane-based small molecules and polymers will be surveyed, covering their structure-property relationships, intramolecular charge transfer properties and solid-state fluorescence quantum yields as functional emissive materials in OLEDs. Also, the importance of the boron atom in triarylborane compounds is emphasized to address the key issues of both fluorescent emitters and their host materials for the construction of high-performance OLEDs.

High Performance Nano-Crystalline Oxide Fuel Cell Materials. Defects, Structures, Interfaces, Transport, and Electrochemistry

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

Barnett, Scott; Poeppelmeier, Ken; Mason, Tom

This project addresses fundamental materials challenges in solid oxide electrochemical cells, devices that have a broad range of important energy applications. Although nano-scale mixed ionically and electronically conducting (MIEC) materials provide an important opportunity to improve performance and reduce device operating temperature, durability issues threaten to limit their utility and have remained largely unexplored. Our work has focused on both (1) understanding the fundamental processes related to oxygen transport and surface-vapor reactions in nano-scale MIEC materials, and (2) determining and understanding the key factors that control their long-term stability. Furthermore, materials stability has been explored under the “extreme” conditions encounteredmore » in many solid oxide cell applications, i.e, very high or very low effective oxygen pressures, and high current density.« less

Performances of some low-cost counter electrode materials in CdS and CdSe quantum dot-sensitized solar cells.

PubMed

Jun, Hieng Kiat; Careem, Mohamed Abdul; Arof, Abdul Kariem

2014-02-10

Different counter electrode (CE) materials based on carbon and Cu2S were prepared for the application in CdS and CdSe quantum dot-sensitized solar cells (QDSSCs). The CEs were prepared using low-cost and facile methods. Platinum was used as the reference CE material to compare the performances of the other materials. While carbon-based materials produced the best solar cell performance in CdS QDSSCs, platinum and Cu2S were superior in CdSe QDSSCs. Different CE materials have different performance in the two types of QDSSCs employed due to the different type of sensitizers and composition of polysulfide electrolytes used. The poor performance of QDSSCs with some CE materials is largely due to the lower photocurrent density and open-circuit voltage. The electrochemical impedance spectroscopy performed on the cells showed that the poor-performing QDSSCs had higher charge-transfer resistances and CPE values at their CE/electrolyte interfaces.

Viscoelastic properties of elastomeric materials for O-ring applications

NASA Technical Reports Server (NTRS)

Bower, Mark V.

1989-01-01

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

Application and Prospects of High-strength Lightweight Materials used in Coal mine

NASA Astrophysics Data System (ADS)

He, Pan

2017-09-01

This paper describes some high-strength lightweight materials used in coal mine, and if their performance can meet the requirements of underground safety for explosion-proof, anti-static, friction sparks mine; and reviewed the species, characteristic, preparation process of high-strength lightweight materials for having inspired lightweight high-strength performance by modifying or changing the synthesis mode used in coal mine equipment.

A high performance scientific cloud computing environment for materials simulations

NASA Astrophysics Data System (ADS)

Jorissen, K.; Vila, F. D.; Rehr, J. J.

2012-09-01

We describe the development of a scientific cloud computing (SCC) platform that offers high performance computation capability. The platform consists of a scientific virtual machine prototype containing a UNIX operating system and several materials science codes, together with essential interface tools (an SCC toolset) that offers functionality comparable to local compute clusters. In particular, our SCC toolset provides automatic creation of virtual clusters for parallel computing, including tools for execution and monitoring performance, as well as efficient I/O utilities that enable seamless connections to and from the cloud. Our SCC platform is optimized for the Amazon Elastic Compute Cloud (EC2). We present benchmarks for prototypical scientific applications and demonstrate performance comparable to local compute clusters. To facilitate code execution and provide user-friendly access, we have also integrated cloud computing capability in a JAVA-based GUI. Our SCC platform may be an alternative to traditional HPC resources for materials science or quantum chemistry applications.

Inorganic nanostructured materials for high performance electrochemical supercapacitors

NASA Astrophysics Data System (ADS)

Liu, Sheng; Sun, Shouheng; You, Xiao-Zeng

2014-01-01

Electrochemical supercapacitors (ES) are a well-known energy storage system that has high power density, long life-cycle and fast charge-discharge kinetics. Nanostructured materials are a new generation of electrode materials with large surface area and short transport/diffusion path for ions and electrons to achieve high specific capacitance in ES. This mini review highlights recent developments of inorganic nanostructure materials, including carbon nanomaterials, metal oxide nanoparticles, and metal oxide nanowires/nanotubes, for high performance ES applications.

Inorganic nanostructured materials for high performance electrochemical supercapacitors.

PubMed

Liu, Sheng; Sun, Shouheng; You, Xiao-Zeng

2014-02-21

Electrochemical supercapacitors (ES) are a well-known energy storage system that has high power density, long life-cycle and fast charge-discharge kinetics. Nanostructured materials are a new generation of electrode materials with large surface area and short transport/diffusion path for ions and electrons to achieve high specific capacitance in ES. This mini review highlights recent developments of inorganic nanostructure materials, including carbon nanomaterials, metal oxide nanoparticles, and metal oxide nanowires/nanotubes, for high performance ES applications.

Application of CFRP with High Hydrogen Gas Barrier Characteristics to Fuel Tanks of Space Transportation System

NASA Astrophysics Data System (ADS)

Yonemoto, Koichi; Yamamoto, Yuta; Okuyama, Keiichi; Ebina, Takeo

In the future, carbon fiber reinforced plastics (CFRPs) with high hydrogen gas barrier performance will find wide applications in all industrial hydrogen tanks that aim at weight reduction; the use of such materials will be preferred to the use of conventional metallic materials such as stainless steel or aluminum. The hydrogen gas barrier performance of CFRP will become an important issue with the introduction of hydrogen-fuel aircraft. It will also play an important role in realizing fully reusable space transportation system that will have high specific tensile CFRP structures. Such materials are also required for the manufacture of high-pressure hydrogen gas vessels for use in the fuel cell systems of automobiles. This paper introduces a new composite concept that can be used to realize CFRPs with high hydrogen gas barrier performance for applications in the cryogenic tanks of fully reusable space transportation system by the incorporation of a nonmetallic crystal layer, which is actually a dense and highly oriented clay crystal laminate. The preliminary test results show that the hydrogen gas barrier characteristics of this material after cryogenic heat shocks and cyclic loads are still better than those of other polymer materials by approximately two orders of magnitude.

Further weight reduction of applications in long glass reinforced polymers

NASA Astrophysics Data System (ADS)

Yanev, A.; Schijve, W.; Martin, C.; Brands, D.

2014-05-01

Long glass reinforced materials are broadly used in the automotive industry due to their good mechanical performance, competitive price and options for functional integration in order to reduce weight. With rapidly changing environmental requirements, a demand for further weight reduction is growing constantly. Designs in LGF-PP can bring light weight solutions in combination with system cost improvement. There are quite some possibilities for applying weight reduction technologies nowadays. These technologies have to be evaluated based on weight reduction potential, but also on mechanical performance of the end application, where the latter is often the key to success. Different weight reduction technologies are applied to SABIC®STAMAX{trade mark, serif} material, a long glass fiber reinforced polypropylene (LGF-PP), in order to investigate and define best application performance. These techniques include: chemical foaming, physical foaming and thin wall applications. Results from this research will be presented, giving a guideline for your development.

Evaluation of Advanced Composite Structures Technologies for Application to NASA's Vision for Space Exploration

NASA Technical Reports Server (NTRS)

Tenney, Darrel R.

2008-01-01

AS&M performed a broad assessment survey and study to establish the potential composite materials and structures applications and benefits to the Constellation Program Elements. Trade studies were performed on selected elements to determine the potential weight or performance payoff from use of composites. Weight predictions were made for liquid hydrogen and oxygen tanks, interstage cylindrical shell, lunar surface access module, ascent module liquid methane tank, and lunar surface manipulator. A key part of this study was the evaluation of 88 different composite technologies to establish their criticality to applications for the Constellation Program. The overall outcome of this study shows that composites are viable structural materials which offer from 20% to 40% weight savings for many of the structural components that make up the Major Elements of the Constellation Program. NASA investment in advancing composite technologies for space structural applications is an investment in America's Space Exploration Program.

Dynamic carrier transport modulation for constructing advanced devices with improved performance by piezotronic and piezo-phototronic effects: a brief review

NASA Astrophysics Data System (ADS)

Guo, Zhen; Pan, Haixi; Li, Chuanyu; Zhang, Lili; Yan, Shuai; Zhang, Wei; Yao, Jia; Tang, Yuguo; Yang, Hongbo; Wu, Yihui; Feng, Liping; Zhou, Lianqun

2017-08-01

Carrier generation, transport, separation, and recombination behaviors can be modulated for improving the performance of semiconductor devices by using piezotronic and piezo-phototronic effects with creating piezopotential in crystals based on non-centrosymmetric semiconductor materials such as group II-VI and III-V semiconductors and transition metal dichalcogenides (TMDCs), which have emerged as attractive materials for electronic/photonic applications because of their novel properties. Until now, much effort has been devoted to improving the performance of devices based on the aforementioned materials through modulation of the carrier behavior. However, due to existing drawbacks, it has been difficult to further enhance the device performance for a built structure. However, effective exploration of the piezotronic and piezo-phototronic effects in these semiconducting materials could pave the way to the realization of high-performance devices. In general, the effective modulation of carrier behavior dynamically in devices such as light-emitting diodes, photodetectors, solar cells, nanogenerators, and so on, remains a key challenge. Due to the polarization of ions in semiconductor materials with noncentral symmetry under external strain, a piezopotential is created considering piezotronic and piezo-photoronic effects, which could dynamically modulate charge carrier transport behaviors across p-n junctions or metal-semiconductor interfaces. Through a combination of these effects and semiconductor properties, the performance of the related devices could be improved and new types of devices such as piezoelectric field-effect transistors and sensors have emerged, with potential applications in self-driven devices for effective energy harvesting and biosensing with high sensitivity, which are different from those traditionally designed and may have potential applications in strained triggered devices. The objective of this review is to briefly introduce the corresponding mechanisms for modulating carrier behavior on the basis of piezotronic and piezo-phototronic effects in materials such as group II-VI and group III-V semiconductors and TMDCs, as well as to discuss possible solutions to effectively enhance the performance of the devices via carrier modulation.

The fabrication of a programmable via using phase-change material in CMOS-compatible technology.

PubMed

Chen, Kuan-Neng; Krusin-Elbaum, Lia

2010-04-02

We demonstrate an energy-efficient programmable via concept using indirectly heated phase-change material. This via structure has maximum phase-change volume to achieve a minimum on resistance for high performance logic applications. Process development and material investigations for this device structure are reported. The device concept is successfully demonstrated in a standard CMOS-compatible technology capable of multiple cycles between on/off states for reconfigurable applications.

An overview of the applications of graphene-based materials in supercapacitors.

PubMed

Huang, Yi; Liang, Jiajie; Chen, Yongsheng

2012-06-25

Due to their unique 2D structure and outstanding intrinsic physical properties, such as extraordinarily high electrical conductivity and large surface area, graphene-based materials exhibit great potential for application in supercapacitors. In this review, the progress made so far for their applications in supercapacitors is reviewed, including electrochemical double-layer capacitors, pseudo-capacitors, and asymmetric supercapacitors. Compared with traditional electrode materials, graphene-based materials show some novel characteristics and mechanisms in the process of energy storage and release. Several key issues for improving the structure of graphene-based materials and for achieving better capacitor performance, along with the current outlook for the field, are also discussed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

STREAMLINED ENVIRONMENTAL LIFE-CYCLE ASSESSMENT: AN APPROACH FOR EVALUATING THE ENVIRONMENTAL PERFORMANCE OF BUILDING MATERIALS

EPA Science Inventory

The report presents the approach that was developed to prepare reports on building materials for the Environmental Resource Guide (ERG), both technical materials reports and applications reports. It also: (1) presents data collection tools that could be used to replicate material...

Electrochemical investigation of MoTe2/rGO composite materials for sodium-ion battery application

NASA Astrophysics Data System (ADS)

Panda, Manas Ranjan; Anish Raj, K.; Sarkar, Ananta; Bao, Qiaoliang; Mitra, Sagar

2018-05-01

2D layered materials are found to be promising anode materials for renewable energy storage devices like sodium and Li-ion batteries and have become attractive options due to their high specific capacity, abundance and low cost. In this work, we synthesized 2D MoTe2 layers embedded in reduced graphene oxide (rGO) anode material for sodium-ion battery applications. 2D MoTe2 was prepared by a solid-state reaction in vacuum at a temperature of 800 °C. The prepared composite material MoTe2/rGO showed excellent electrochemical performance against the sodium metal. The discharge capacity of MoTe2/rGO was observed to be 280 mAh g-1 at a current rate of 1.0 A g-1 for 100 cycles. rGO plays an important role in embedding the MoTe2 structure, thus improving the electrical and mechanical properties, leading to a superior cycling stability and excellent electrochemical performances of MoTe2 for sodium-ion battery applications.

Perovskite Materials: Solar Cell and Optoelectronic Applications

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

Yang, Bin; Geohegan, David B; Xiao, Kai

2017-01-01

Hybrid organometallic trihalide perovskites are promising candidates in the applications for next-generation, high-performance, low-cost optoelectronic devices, including photovoltaics, light emitting diodes, and photodetectors. Particularly, the solar cells based on this type of materials have reached 22% lab scale power conversion efficiency in only about seven years, comparable to the other thin film photovoltaic technologies. Hybrid perovskite materials not only exhibit superior optoelectronic properties, but also show many interesting physical properties such as ion migration and defect physics, which may allow the exploration of more device functionalities. In this article, the fundamental understanding of the interrelationships between crystal structure, electronic structure,more » and material properties is discussed. Various chemical synthesis and processing methods for superior device performance in solar cells and optoelectronic devices are reviewed.« less

Polymer-pyrolysis assisted synthesis of vanadium trioxide and carbon nanocomposites as high performance anode materials for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Dong, Yucheng; Ma, Ruguang; Hu, Mingjun; Cheng, Hua; Lee, Jong-Min; Li, Yang Yang; Zapien, Juan Antonio

2014-09-01

We present a simple polymer-pyrolysis assisted method to prepare vanadium trioxide and carbon nanocomposites as an advanced anode material for lithium-ion batteries. The as-prepared material deliver a superior battery performance with highly retained capacity of ∼780 mAh g-1 over 100 cycles at a current density of 200 mA g-1, showing excellent cyclic stability, and good rate capability. The improved electrochemical performance of vanadium trioxide and carbon nanocomposites electrode makes it promising as a suitable anode material for practical battery applications.

One-dimensional carbon-sulfur composite fibers for Na-S rechargeable batteries operating at room temperature.

PubMed

Hwang, Tae Hoon; Jung, Dae Soo; Kim, Joo-Seong; Kim, Byung Gon; Choi, Jang Wook

2013-09-11

Na-S batteries are one type of molten salt battery and have been used to support stationary energy storage systems for several decades. Despite their successful applications based on long cycle lives and low cost of raw materials, Na-S cells require high temperatures above 300 °C for their operations, limiting their propagation into a wide range of applications. Herein, we demonstrate that Na-S cells with solid state active materials can perform well even at room temperature when sulfur-containing carbon composites generated from a simple thermal reaction were used as sulfur positive electrodes. Furthermore, this structure turned out to be robust during repeated (de)sodiation for ~500 cycles and enabled extraordinarily high rate performance when one-dimensional morphology is adopted using scalable electrospinning processes. The current study suggests that solid-state Na-S cells with appropriate atomic configurations of sulfur active materials could cover diverse battery applications where cost of raw materials is critical.

Prospects and progress of high Tc superconductivity for space applications

NASA Technical Reports Server (NTRS)

Romanofsky, Robert R.; Sokoloski, Marty M.

1991-01-01

Current research in the area of high temperature superconductivity is organized around four key areas: communications and data, sensors and cryogenics, propulsion and power, and space materials technology. Recently, laser ablated YBa2Cu3O(7-x) films on LaAlO3 produced far superior RF characteristics when compared to metallic films on the same substrate. The achievement has enabled a number of unique microwave device applications, such as low insertion loss phase shifters and high-Q filters. Melt texturing and melt-quenched techniques are being used to produce bulk material with optimized magnetic properties. These yttrium-enriched materials possess enhanced flux pinning characteristics and could lead to prototype cryocooler bearings. Significant progress has also occurred in bolometer and current lead technology. Studies were conducted to evaluate the effect of high temperature superconducting materials on the performance and life of high power magnetoplasma-dynamic thrusters. Extended studies were also performed to evaluate the benefit of superconducting magnetic energy storage for LEO space station, lunar, and Mars mission applications.

High performance polymer development

NASA Technical Reports Server (NTRS)

Hergenrother, Paul M.

1991-01-01

The term high performance as applied to polymers is generally associated with polymers that operate at high temperatures. High performance is used to describe polymers that perform at temperatures of 177 C or higher. In addition to temperature, other factors obviously influence the performance of polymers such as thermal cycling, stress level, and environmental effects. Some recent developments at NASA Langley in polyimides, poly(arylene ethers), and acetylenic terminated materials are discussed. The high performance/high temperature polymers discussed are representative of the type of work underway at NASA Langley Research Center. Further improvement in these materials as well as the development of new polymers will provide technology to help meet NASA future needs in high performance/high temperature applications. In addition, because of the combination of properties offered by many of these polymers, they should find use in many other applications.

Phenomenally High Transduction Air/gas Transducers for Practical Non-Contact Ultrasonic Applications

NASA Astrophysics Data System (ADS)

Bhardwaj, Mahesh C.

2009-03-01

Based on novel acoustic impedance matching layers and high coupling piezoelectric materials this paper describes exceptionally high air/gas transduction ultrasonic transducers. By providing applications oriented performance of these transducers we also usher in the era of much desired Non-Contact Ultrasound (NCU) testing and analysis of a wide range of materials including early stage formation of materials such as uncured composite prepregs, green ceramics and powder metals, plastics, elastomers, porous, hygroscopic, chemically bonded and other materials. Besides quality control, ultimately NCU offers timely opportunities for cost-effective materials production, energy savings, and environment protection.

Graphene and Carbon Quantum Dot-Based Materials in Photovoltaic Devices: From Synthesis to Applications

PubMed Central

Paulo, Sofia; Palomares, Emilio; Martinez-Ferrero, Eugenia

2016-01-01

Graphene and carbon quantum dots have extraordinary optical and electrical features because of their quantum confinement properties. This makes them attractive materials for applications in photovoltaic devices (PV). Their versatility has led to their being used as light harvesting materials or selective contacts, either for holes or electrons, in silicon quantum dot, polymer or dye-sensitized solar cells. In this review, we summarize the most common uses of both types of semiconducting materials and highlight the significant advances made in recent years due to the influence that synthetic materials have on final performance. PMID:28335285

Report of the Panel on Materials

NASA Technical Reports Server (NTRS)

Diefendorf, Russell J.; Grisaffe, Salvatore J.

1984-01-01

Materials and manufacturing technology are critical to advanced aircraft and permeate all disciplines. Current aircraft systems employ a variety of materials, each selected to provide the best vehicle design in terms of performance, safety, reliability, manufacturability, and life cycle cost. However, a mistake in materials selection could bankrupt an airframe or engine manufacturer. Thus, the introduction of new materials is a slow process. Generally, new materials are used initially in noncritical components until their performance in service can be confirmed. Then, as confidence grows, they are used in more and more critical applications. Finally, if appropriate, new materials are used in critical, static elements and then in dynamic components. Thus, because the nominal time for development of a conventional monolithic material ranges from 5 to 10 years there is a 10- to 15- year lag between laboratory effort and introduction into service. Therefore, to assure the availability of materials suitable for production aircraft and engines in the year 2000, the concepts already must have been identified and must be progressing along evolutionary paths toward application. Trends, actual and projected, in the use of materials for commercial engines are shown in Figure 4-1. Related military applications are projected to follow similar paths. The new actor will be composites. The panel examined a wide range of materials important to all aspects of aircraft development, airframe structures, propulsion systems and for other important aircraft subsystems. These are addressed in the body of the report in terms of the current state of the art, opportunities for improvement, and barriers to achievement of projected benefits. This is followed by projections of the progress of technology that could be realized by the year 2000 with the application of appropriate resources.

Safer energetic materials by a nanotechnological approach

NASA Astrophysics Data System (ADS)

Siegert, Benny; Comet, Marc; Spitzer, Denis

2011-09-01

Energetic materials - explosives, thermites, populsive powders - are used in a variety of military and civilian applications. Their mechanical and electrostatic sensitivity is high in many cases, which can lead to accidents during handling and transport. These considerations limit the practical use of some energetic materials despite their good performance. For industrial applications, safety is one of the main criteria for selecting energetic materials. The sensitivity has been regarded as an intrinsic property of a substance for a long time. However, in recent years, several approaches to lower the sensitivity of a given substance, using nanotechnology and materials engineering, have been described. This feature article gives an overview over ways to prepare energetic (nano-)materials with a lower sensitivity.Energetic materials - explosives, thermites, populsive powders - are used in a variety of military and civilian applications. Their mechanical and electrostatic sensitivity is high in many cases, which can lead to accidents during handling and transport. These considerations limit the practical use of some energetic materials despite their good performance. For industrial applications, safety is one of the main criteria for selecting energetic materials. The sensitivity has been regarded as an intrinsic property of a substance for a long time. However, in recent years, several approaches to lower the sensitivity of a given substance, using nanotechnology and materials engineering, have been described. This feature article gives an overview over ways to prepare energetic (nano-)materials with a lower sensitivity. Electronic supplementary information (ESI) available: Experimental details for the preparation of the V2O5@CNF/Al nanothermite; X-ray diffractogram of the V2O5@CNF/Al combustion residue; installation instructions and source code for the nt-timeline program. See DOI: 10.1039/c1nr10292c

Feasibility of introducing ferromagnetic materials to onboard bulk high-Tc superconductors to enhance the performance of present maglev systems

NASA Astrophysics Data System (ADS)

Deng, Zigang; Wang, Jiasu; Zheng, Jun; Zhang, Ya; Wang, Suyu

2013-02-01

Performance improvement is a long-term research task for the promotion of practical application of promising high-temperature superconducting (HTS) magnetic levitation (maglev) vehicle technologies. We studied the feasibility to enhance the performance of present HTS Maglev systems by introducing ferromagnetic materials to onboard bulk superconductors. The principle here is to make use of the high magnetic permeability of ferromagnetic materials to alter the flux distribution of the permanent magnet guideway for the enhancement of magnetic field density at the position of the bulk superconductors. Ferromagnetic iron plates were added to the upper surface of bulk superconductors and their geometric and positioning effects on the maglev performance were investigated experimentally. Results show that the guidance performance (stability) was enhanced greatly for a particular setup when compared to the present maglev system which is helpful in the application where large guidance forces are needed such as maglev tracks with high degrees of curves.

Superconducting RF materials other than bulk niobium: a review

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

Valente-Feliciano, Anne-Marie

For the last five decades, bulk niobium (Nb) has been the material of choice for Superconducting RF (SRF) cavity applications. Thin film alternatives such as Nb and other higher-Tc materials, mainly Nb compounds and A15 compounds, have been investigated with moderate effort in the past. In recent years, RF cavity performance has approached the theoretical limit for bulk Nb. For further improvement of RF cavity performance for future accelerator projects, research interest is renewed towards alternatives to bulk Nb. Institutions around the world are now investing renewed efforts in the investigation of Nb thin films and superconductors with higher transitionmore » temperature Tc for application to SRF cavities. Our paper gives an overview of the results obtained so far and challenges encountered for Nb films as well as other materials, such as Nb compounds, A15 compounds, MgB2, and oxypnictides, for SRF cavity applications. An interesting alternative using a Superconductor-Insulator- Superconductor multilayer approach has been recently proposed to delay the vortex penetration in Nb surfaces. This could potentially lead to further improvement in RF cavities performance using the benefit of the higher critical field Hc of higher-Tc superconductors without being limited with their lower Hc1.« less

Superconducting RF materials other than bulk niobium: a review

DOE PAGES

Valente-Feliciano, Anne-Marie

2016-09-26

For the last five decades, bulk niobium (Nb) has been the material of choice for Superconducting RF (SRF) cavity applications. Thin film alternatives such as Nb and other higher-Tc materials, mainly Nb compounds and A15 compounds, have been investigated with moderate effort in the past. In recent years, RF cavity performance has approached the theoretical limit for bulk Nb. For further improvement of RF cavity performance for future accelerator projects, research interest is renewed towards alternatives to bulk Nb. Institutions around the world are now investing renewed efforts in the investigation of Nb thin films and superconductors with higher transitionmore » temperature Tc for application to SRF cavities. Our paper gives an overview of the results obtained so far and challenges encountered for Nb films as well as other materials, such as Nb compounds, A15 compounds, MgB2, and oxypnictides, for SRF cavity applications. An interesting alternative using a Superconductor-Insulator- Superconductor multilayer approach has been recently proposed to delay the vortex penetration in Nb surfaces. This could potentially lead to further improvement in RF cavities performance using the benefit of the higher critical field Hc of higher-Tc superconductors without being limited with their lower Hc1.« less

Performance characterization of active fiber-composite actuators for helicopter rotor blade applications

NASA Astrophysics Data System (ADS)

Wickramasinghe, Viresh K.; Hagood, Nesbitt W.

2002-07-01

The primary objective of this work was to characterize the performance of the Active Fiber Composite (AFC) actuator material system for the Boeing Active Material Rotor (AMR) blade application. The AFCs were a new structural actuator system consisting of piezoceramic fibers embedded in an epoxy matrix and sandwiched between interdigitated electrodes to orient the driving electric field in the fiber direction to use the primary piezoelectric effect. These actuators were integrated directly into the blade spar laminate as active plies within the composite structure to perform structural actuation for vibration control in helicopters. Therefore, it was necessary to conduct extensive electromechanical material characterization to evaluate AFCs both as actuators and as structural components of the rotor blade. The characterization tests designed to extract important electromechanical properties under simulated blade operating conditions included stress-strain tests, free strain tests and actuation under tensile load tests. This paper presents the test results as well as the comprehensive testing process developed to evaluate the relevant AFC material properties. The results from this comprehensive performance characterization of the AFC material system supported the design and operation of the Boeing AMR blade scheduled for hover and forward flight wind tunnel tests.

Aircraft surface coatings study: Energy efficient transport program. [sprayed and adhesive bonded coatings for drag reduction

NASA Technical Reports Server (NTRS)

1979-01-01

Surface coating materials for application on transport type aircraft to reduce drag, were investigated. The investigation included two basic types of materials: spray on coatings and adhesively bonded films. A cost/benefits analysis was performed, and recommendations were made for future work toward the application of this technology.

Graphene-like layers as promising chemiresistive sensing material for detection of alcohols at low concentration

NASA Astrophysics Data System (ADS)

Gargiulo, Valentina; Alfano, Brigida; Di Capua, Roberto; Alfé, Michela; Vorokhta, Mykhailo; Polichetti, Tiziana; Massera, Ettore; Miglietta, Maria Lucia; Schiattarella, Chiara; Di Francia, Girolamo

2018-01-01

In the manifold of materials for Volatile Organic Compound (VOC) sensing, graphene related materials (GRMs) gain special attention thanks to their versatility and overall chemico-physical tunability as a function of specific applications. In this work, the sensing performances of graphene-like (GL) layers, a new material belonging to the GRM family, are tested against ethanol and n-butanol. Two typologies of GL samples were produced by employing two different approaches and tested in view of their application as VOC sensors. The experiments were performed under atmospheric pressure, in dry air, and at room temperature and demonstrated that the sensing capabilities are related to the film surface features. The results indicated that GL films are promising candidates for the detection of low concentrations of VOCs at room temperature. The present investigation thus paves the way for VOC sensing optimization using cost-effective and easily scalable materials.

Benchmarking organic mixed conductors for transistors.

PubMed

Inal, Sahika; Malliaras, George G; Rivnay, Jonathan

2017-11-24

Organic mixed conductors have garnered significant attention in applications from bioelectronics to energy storage/generation. Their implementation in organic transistors has led to enhanced biosensing, neuromorphic function, and specialized circuits. While a narrow class of conducting polymers continues to excel in these new applications, materials design efforts have accelerated as researchers target new functionality, processability, and improved performance/stability. Materials for organic electrochemical transistors (OECTs) require both efficient electronic transport and facile ion injection in order to sustain high capacity. In this work, we show that the product of the electronic mobility and volumetric charge storage capacity (µC*) is the materials/system figure of merit; we use this framework to benchmark and compare the steady-state OECT performance of ten previously reported materials. This product can be independently verified and decoupled to guide materials design and processing. OECTs can therefore be used as a tool for understanding and designing new organic mixed conductors.

Nondestructive evaluation of a ceramic matrix composite material

NASA Technical Reports Server (NTRS)

Grosskopf, Paul P.; Duke, John C., Jr.

1992-01-01

Monolithic ceramic materials have proven their usefulness in many applications, yet, their potential for critical structural applications is limited because of their sensitivity to small imperfections. To overcome this extreme sensitivity to small imperfections, ceramic matrix composite materials have been developed that have the ability to withstand some distributed damage. A borosilicate glass reinforced with several layers of silicon-carbide fiber mat has been studied. Four-point flexure and tension tests were performed not only to determine some of the material properties, but also to initiate a controlled amount of damage within each specimen. Acousto-ultrasonic (AU) measurements were performed periodically during mechanical testing. This paper will compare the AU results to the mechanical test results and data from other nondestructive methods including acoustic emission monitoring and X-ray radiography. It was found that the AU measurements were sensitive to the damage that had developed within the material.

Molecular Design of Benzodithiophene-Based Organic Photovoltaic Materials.

PubMed

Yao, Huifeng; Ye, Long; Zhang, Hao; Li, Sunsun; Zhang, Shaoqing; Hou, Jianhui

2016-06-22

Advances in the design and application of highly efficient conjugated polymers and small molecules over the past years have enabled the rapid progress in the development of organic photovoltaic (OPV) technology as a promising alternative to conventional solar cells. Among the numerous OPV materials, benzodithiophene (BDT)-based polymers and small molecules have come to the fore in achieving outstanding power conversion efficiency (PCE) and breaking 10% efficiency barrier in the single junction OPV devices. Remarkably, the OPV device featured by BDT-based polymer has recently demonstrated an impressive PCE of 11.21%, indicating the great potential of this class of materials in commercial photovoltaic applications. In this review, we offered an overview of the organic photovoltaic materials based on BDT from the aspects of backbones, functional groups, alkyl chains, and device performance, trying to provide a guideline about the structure-performance relationship. We believe more exciting BDT-based photovoltaic materials and devices will be developed in the near future.

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

Yang, Ji-Hui; Yuan, Qinghong; Deng, Huixiong

Current thermoelectric (TE) materials often have low performance or contain less abundant and/or toxic elements, thus limiting their large-scale applications. Therefore, new TE materials with high efficiency and low cost are strongly desirable. Here we demonstrate that SiS and SiSe monolayers made from nontoxic and earth-abundant elements intrinsically have low thermal conductivities arising from their low-frequency optical phonon branches with large overlaps with acoustic phonon modes, which is similar to the state-of-the-art experimentally demonstrated material SnSe with a layered structure. Together with high thermal power factors due to their two-dimensional nature, they show promising TE performances with large figure ofmore » merit (ZT) values exceeding 1 or 2 over a wide range of temperatures. We establish some basic understanding of identifying layered materials with low thermal conductivities, which can guide and stimulate the search and study of other layered materials for TE applications.« less

Mechanical Components from Highly Recoverable, Low Apparent Modulus Materials

NASA Technical Reports Server (NTRS)

Padula, Santo, II (Inventor); Noebe, Ronald D. (Inventor); Stanford, Malcolm K. (Inventor); DellaCorte, Christopher (Inventor)

2015-01-01

A material for use as a mechanical component is formed of a superelastic intermetallic material having a low apparent modulus and a high hardness. The superelastic intermetallic material is conditioned to be dimensionally stable, devoid of any shape memory effect and have a stable superelastic response without irrecoverable deformation while exhibiting strains of at least 3%. The method of conditioning the superelastic intermetallic material is described. Another embodiment relates to lightweight materials known as ordered intermetallics that perform well in sliding wear applications using conventional liquid lubricants and are therefore suitable for resilient, high performance mechanical components such as gears and bearings.

Nanostructured porous carbons with high rate cycling and floating performance for supercapacitor application

NASA Astrophysics Data System (ADS)

Ochai-Ejeh, F. O.; Momodu, D. Y.; Madito, M. J.; Khaleed, A. A.; Oyedotun, K. O.; Ray, S. C.; Manyala, N.

2018-05-01

Biomass-derived activated carbon from cork (Quercus Suber) (ACQS) was prepared via a two-step environment-friendly route using mild KHCO3 as the activating agent. This synthesis route makes the material produced less toxic for usage as electrode material for energy storage application. The ACQS has well-defined microporous and mesoporous structures and a specific surface area of 1056.52 m2 g-1 and pore volume of 0.64 cm3 g-1. Three-electrode tests were performed in 6 M KOH, 1 M H2SO4 and 3 M KNO3 aqueous electrolytes, to analyse the material performance in acidic, basic, and neutral media. Specific capacitance values (Cs) of 133 F g-1/167 F g-1 at 1.0 A g-1 was obtained in 3 M KNO3 in the positive/negative potential windows. Due to the observed best performance in neutral 3 M KNO3, further electrochemical analysis of the symmetric device was carried out using the same electrolyte. The device displayed a Cs value of 122 F g-1, energy and power densities of ˜14 W h kg-1 and 450 W kg-1 respectively; at 0.5 A g-1. The device also displayed an excellent stability after potentiostatic floating at a maximum voltage of 1.8 V for 120 h and ˜100% capacitance retention after 10,000 charge-discharge cycles. The excellent stability makes the cork-derived material a potential excellent, cost-effective material for supercapacitor application.

Multi-layered Poly-Dimethylsiloxane As A Non-Hermetic Packaging Material For Medical MEMS

PubMed Central

Lachhman, S.; Zorman, C.A.; Ko, W.H.

2012-01-01

Poly-dimethylsiloxane (PDMS) is an attractive material for packaging implantable biomedical microdevices owing to its biocompatibility, ease in application, and bio-friendly mechanical properties. Unfortunately, devices encapsulated by PDMS lack the longevity for use in chronic implant applications due to defect-related moisture penetration through the packaging layer. This paper describes an effort to improve the performance of PDMS as packaging material by constructing the encapsulant from multiple, thin layers of PDMS as a part of a polymeric multi-material package PMID:23366225

Sintered Cathodes for All-Solid-State Structural Lithium-Ion Batteries

NASA Technical Reports Server (NTRS)

Huddleston, William; Dynys, Frederick; Sehirlioglu, Alp

2017-01-01

All-solid-state structural lithium ion batteries serve as both structural load-bearing components and as electrical energy storage devices to achieve system level weight savings in aerospace and other transportation applications. This multifunctional design goal is critical for the realization of next generation hybrid or all-electric propulsion systems. Additionally, transitioning to solid state technology improves upon battery safety from previous volatile architectures. This research established baseline solid state processing conditions and performance benchmarks for intercalation-type layered oxide materials for multifunctional application. Under consideration were lithium cobalt oxide and lithium nickel manganese cobalt oxide. Pertinent characteristics such as electrical conductivity, strength, chemical stability, and microstructure were characterized for future application in all-solid-state structural battery cathodes. The study includes characterization by XRD, ICP, SEM, ring-on-ring mechanical testing, and electrical impedance spectroscopy to elucidate optimal processing parameters, material characteristics, and multifunctional performance benchmarks. These findings provide initial conditions for implementing existing cathode materials in load bearing applications.

Performance of coincidence-based PSD on LiF/ZnS Detectors for Multiplicity Counting

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

Robinson, Sean M.; Stave, Sean C.; Lintereur, Azaree

Abstract: Mass accountancy measurement is a nuclear nonproliferation application which utilizes coincidence and multiplicity counters to verify special nuclear material declarations. With a well-designed and efficient detector system, several relevant parameters of the material can be verified simultaneously. 6LiF/ZnS scintillating sheets may be used for this purpose due to a combination of high efficiency and short die-away times in systems designed with this material, but involve choices of detector geometry and exact material composition (e.g., the addition of Ni-quenching in the material) that must be optimized for the application. Multiplicity counting for verification of declared nuclear fuel mass involves neutronmore » detection in conditions where several neutrons arrive in a short time window, with confounding gamma rays. This paper considers coincidence-based Pulse-Shape Discrimination (PSD) techniques developed to work under conditions of high pileup, and the performance of these algorithms with different detection materials. Simulated and real data from modern LiF/ZnS scintillator systems are evaluated with these techniques and the relationship between the performance under pileup and material characteristics (e.g., neutron peak width and total light collection efficiency) are determined, to allow for an optimal choice of detector and material.« less

Growth of 2D Materials and Application in Electrochemical Energy Conversion

NASA Astrophysics Data System (ADS)

Ye, Gonglan

The discovery of graphene in 2004 has generated numerous interests among scientists for graphene's versatile potentials. The enthusiasm for graphene has recently been extended to other members of two-dimensional (2D) materials for applications in electronics, optoelectronics, and catalysis. Different from graphene, atomically-thin transition metal dichalcogenides (TMDs) have varied band gaps and would benefit for applications in the semiconductor industry. One of the promising applications of 2D TMDs is for 2D integrated circuits to replace current Si based electronics. In addition to electronic applications, 2D materials are also good candidates for electrochemical energy storage and conversion due to their large surface area and atomic thickness. This thesis mainly focuses on the synthesis of 2D materials and their application in energy conversion. Firstly, we focus on the synthesis of two-dimensional Tin Disulfide (SnS2). SnS2 is considered to be a novel material in 2D family. 2D SnS2 has a large band gap ( 2.8 eV) and high carrier mobility, which makes it a potential applicant for electronics. Monolayer SnS2 with large scale and high crystal quality was successfully synthesized by chemical vapor deposition (CVD), and its performance as a photodetector was examined. The next chapter demonstrated a generic method for growing millimeter-scale single crystals as well as wafer-scale thin films of TMDs. This generic method was obtained by studying the precursors' behavior and the flow dynamics during the CVD process of growing MoSe2, and was extended to other TMD layers such as millimeter-scale WSe2 single crystals. Understanding the growth processes of high quality large area monolayers of TMDs is crucial for further fundamental research as well as future development for scalable complex electronics. Besides the synthesis of 2D materials with high qualities, we further explored the relationship between defects and electrochemical properties. By directly observing and correlating the microscale structural changes of TMD monolayers such as MoS2 to the catalytic properties, we were able to provide insight on the fundamental catalytic mechanism for hydrogen evolution reaction. Finally, we used the 2D materials to build up 3D architectures, showing excellent performance in energy storage and conversion. For example, we used graphene as a conductive scaffold to support vanadium oxide (V 2O5) on nanoscale, and achieved high performances for supercapacitors. Also, we applied the Pt anchored N-doped graphene nanoribbons as the catalyst for methanol electro oxidation, and reported the best performance among Pt/Carbon-based catalysts.

LDHs as electrode materials for electrochemical detection and energy storage: supercapacitor, battery and (bio)-sensor.

PubMed

Mousty, Christine; Leroux, Fabrice

2012-11-01

From an exhaustive overview based on applicative academic literature and patent domain, the relevance of Layered Double Hydroxide (LDHs) as electrode materials for electrochemical detection of organic molecules having environmental or health impact and energy storage is evaluated. Specifically the focus is driven on their application as supercapacitor, alkaline or lithium battery and (bio)-sensor. Inherent to the high versatility of their chemical composition, charge density, anion exchange capability, LDH-based materials are extensively studied and their performances for such applications are reported. Indeed the analytical characteristics (sensitivity and detection limit) of LDH-based electrodes are scrutinized, and their specific capacity or capacitance as electrode battery or supercapacitor materials, are detailed.

High Performance Polymers and Composites (HiPPAC) Center

NASA Technical Reports Server (NTRS)

Mintz, Eric A.; Veazie, David

2005-01-01

NASA University Research Centers funding has allowed Clark Atlanta University (CAU) to establish a High Performance Polymers and Composites (HiPPAC) Research Center. Clark Atlanta University, through the HiPPAC Center has consolidated and expanded its polymer and composite research capabilities through the development of research efforts in: (1) Synthesis and characterization of polymeric NLO, photorefractive, and piezoelectric materials; (2) Characterization and engineering applications of induced strain smart materials; (3) Processable polyimides and additives to enhance polyimide processing for composite applications; (4) Fabrication and mechanical characterization of polymer based composites.

Parallel programming of industrial applications

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

Heroux, M; Koniges, A; Simon, H

1998-07-21

In the introductory material, we overview the typical MPP environment for real application computing and the special tools available such as parallel debuggers and performance analyzers. Next, we draw from a series of real applications codes and discuss the specific challenges and problems that are encountered in parallelizing these individual applications. The application areas drawn from include biomedical sciences, materials processing and design, plasma and fluid dynamics, and others. We show how it was possible to get a particular application to run efficiently and what steps were necessary. Finally we end with a summary of the lessons learned from thesemore » applications and predictions for the future of industrial parallel computing. This tutorial is based on material from a forthcoming book entitled: "Industrial Strength Parallel Computing" to be published by Morgan Kaufmann Publishers (ISBN l-55860-54).« less

Additive Manufacturing of High-Performance 316L Stainless Steel Nanocomposites via Selective Laser Melting

NASA Astrophysics Data System (ADS)

AlMangour, Bandar Abdulaziz

Austenitic 316L stainless steel alloy is an attractive industrial material combining outstanding corrosion resistance, ductility, and biocompatibility, with promising structural applications and biomedical uses. However, 316L has low strength and wear resistance, limiting its high-performance applicability. Adding secondary hard nanoscale reinforcements to steel matrices, thereby forming steel-matrix nanocomposites (SMCs), can overcome these problems, improving the performance and thereby the applicability of 316L. However, SMC parts with complex-geometry cannot be easily achieved limiting its application. This can be avoided through additive manufacturing (AM) by generating layer-by-layer deposition using computer-aided design data. Expanding the range of AM-applicable materials is necessary to fulfill industrial demand. This dissertation presents the characteristics of new AM-processed high-performance 316L-matrix nanocomposites with nanoscale TiC or TiB2 reinforcements, addressing specific aspects of material design, process control and optimization, and physical metallurgy theory. The nanocomposites were prepared by high-energy ball-milling and consolidated by AM selective laser melting (SLM). Continuous and refined ring-like network structures were obtained with homogenously distributed reinforcements. Additional grain refinement occurred with reinforcement addition, attributed to nanoparticles acting as nuclei for heterogeneous nucleation. The influence of reinforcement content was first investigated; mechanical and tribological behaviors improved with increased reinforcement contents. The compressive yield strengths of composites with TiB2 or TiC reinforcements were approximately five or two times those of 316L respectively. Hot isostatic pressing post-treatment effectively eliminated major cracks and pores in SLM-fabricated components. The effects of the SLM processing parameters on the microstructure and mechanical performance were also investigated. Laser re-melting through double-scanning created higher-density SLM-processed parts with improved mechanical properties but longer production times. Certain scanning patterns minimized texture, creating near-isotropic structures. The energy density eta crucially improved densification at the expense of increased grain size, causing mechanical behavior tradeoffs. It also influenced the size and dispersion state of TiC. In-situ SMCs were fabricated by SLM, an encouraging low-cost processing approach for high-performance parts. Interestingly, in-situ SMCs exhibited higher microhardness values in comparison to the ex-situ composites under fixed SLM processing conditions because of fine, uniform reinforcement distribution. The developed nanocomposites show promise as high-performance materials. Future research is suggested for strategic material developments.

Growth and applications of GeSn-related group-IV semiconductor materials

PubMed Central

Zaima, Shigeaki; Nakatsuka, Osamu; Taoka, Noriyuki; Kurosawa, Masashi; Takeuchi, Wakana; Sakashita, Mitsuo

2015-01-01

We review the technology of Ge1−xSnx-related group-IV semiconductor materials for developing Si-based nanoelectronics. Ge1−xSnx-related materials provide novel engineering of the crystal growth, strain structure, and energy band alignment for realising various applications not only in electronics, but also in optoelectronics. We introduce our recent achievements in the crystal growth of Ge1−xSnx-related material thin films and the studies of the electronic properties of thin films, metals/Ge1−xSnx, and insulators/Ge1−xSnx interfaces. We also review recent studies related to the crystal growth, energy band engineering, and device applications of Ge1−xSnx-related materials, as well as the reported performances of electronic devices using Ge1−xSnx related materials. PMID:27877818

Growth and applications of GeSn-related group-IV semiconductor materials.

PubMed

Zaima, Shigeaki; Nakatsuka, Osamu; Taoka, Noriyuki; Kurosawa, Masashi; Takeuchi, Wakana; Sakashita, Mitsuo

2015-08-01

We review the technology of Ge 1- x Sn x -related group-IV semiconductor materials for developing Si-based nanoelectronics. Ge 1- x Sn x -related materials provide novel engineering of the crystal growth, strain structure, and energy band alignment for realising various applications not only in electronics, but also in optoelectronics. We introduce our recent achievements in the crystal growth of Ge 1- x Sn x -related material thin films and the studies of the electronic properties of thin films, metals/Ge 1- x Sn x , and insulators/Ge 1- x Sn x interfaces. We also review recent studies related to the crystal growth, energy band engineering, and device applications of Ge 1- x Sn x -related materials, as well as the reported performances of electronic devices using Ge 1- x Sn x related materials.

DEVICE TECHNOLOGY. Nanomaterials in transistors: From high-performance to thin-film applications.

PubMed

Franklin, Aaron D

2015-08-14

For more than 50 years, silicon transistors have been continuously shrunk to meet the projections of Moore's law but are now reaching fundamental limits on speed and power use. With these limits at hand, nanomaterials offer great promise for improving transistor performance and adding new applications through the coming decades. With different transistors needed in everything from high-performance servers to thin-film display backplanes, it is important to understand the targeted application needs when considering new material options. Here the distinction between high-performance and thin-film transistors is reviewed, along with the benefits and challenges to using nanomaterials in such transistors. In particular, progress on carbon nanotubes, as well as graphene and related materials (including transition metal dichalcogenides and X-enes), outlines the advances and further research needed to enable their use in transistors for high-performance computing, thin films, or completely new technologies such as flexible and transparent devices. Copyright © 2015, American Association for the Advancement of Science.

InAs/GaInSb strained layer superlattice as an infrared detector material: an overview

NASA Astrophysics Data System (ADS)

Johnson, Jeffrey L.

2000-04-01

The investigation of the InAs/Ga1-xInxSb strained layer superlattice (SLS) has been largely motivated by the promise of overcoming limitations of current mature high-performance IR detectors, such as those using HgCdTe and extrinsic silicon. It also offers fundamentally superior performance over other newly emerging III-V bandgap- engineered materials such as QWIPs. The inherent properties of the InAs/GaInSb SLS have identified it as an attractive alternative for niche VLWIR applications requiring high performance under low backgrounds at operating temperatures > 40K. If this material system proves to meet the stringent demands of VLWIR applications, it will most certainly play a significant role as an alternative materials for photovoltaic focal pane arrays operating in the LWIR and MWIR regimes as well. This paper is an overview of SLS technology development, and focuses on critical development needs as seen from the perspective of the IR detector industry.

Nano-particle modified stationary phases for high-performance liquid chromatography.

PubMed

Nesterenko, Ekaterina P; Nesterenko, Pavel N; Connolly, Damian; He, Xiaoyun; Floris, Patrick; Duffy, Emer; Paull, Brett

2013-08-07

This review covers the latest developments and applications of nano-materials in stationary phase development for various modes of high-performance liquid chromatography. Specific attention is placed upon the development of new composite phases, including the synthetic and immobilisation strategies used, to produce either encapsulated nano-particles, or surface attached nano-particles, layers, coatings and other structures. The resultant chromatographic applications, where applicable, are discussed with comment upon enhanced selectivity and/or efficiency of the nano-particle modified phases, where such effects have been identified. In the main this review covers developments over the past five years and is structured according to the nature of the nano-particles themselves, including carbonaceous, metallic, inorganic, and organopolymer based materials.

Microwave Processing of Materials

DTIC Science & Technology

1994-01-01

up to many meters in electrically insulating materials, such as ceramics, polymers, and certain composite materials. As discussed in Chapter 2, the...for University of Illinois, Urbana Center: High Performance Polymeric Materials Technology 1206 West Green Street Adhesives & Composites United...Michigan State University, application of microwave processing to polymers and polymer composites Dr. Raymond Decker, University Science Partners

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

Pawlowski, Alex E.; Splitter, Derek A.; Muth, Thomas R.

Additive manufacturing by itself provides many benefits, but by combining different materials processing techniques like traditional casting with additive manufacturing to create hybrid processes, custom materials can be tailor-made and mass produced for applications with specific performance needs.

Biological issues in materials science and engineering: Interdisciplinarity and the bio-materials paradigm

NASA Astrophysics Data System (ADS)

Murr, L. E.

2006-07-01

Biological systems and processes have had, and continue to have, important implications and applications in materials extraction, processing, and performance. This paper illustrates some interdisciplinary, biological issues in materials science and engineering. These include metal extraction involving bacterial catalysis, galvanic couples, bacterial-assisted corrosion and degradation of materials, biosorption and bioremediation of toxic and other heavy metals, metal and material implants and prostheses and related dental and medical biomaterials developments and applications, nanomaterials health benefits and toxicity issue, and biomimetics and biologically inspired materials developments. These and other examples provide compelling evidence and arguments for emphasizing biological sicences in materials science and engineering curricula and the implementation of a bio-materials paradigm to facilitate the emergence of innovative interdisciplinarity involving the biological sciences and materials sciences and engineering.

Niobium Application, Metallurgy and Global Trends in Pressure Vessel Steels

NASA Astrophysics Data System (ADS)

Jansto, Steven G.

Niobium-containing high strength steel materials have been developed for a variety of pressure vessel applications. Through the application of these Nb-bearing steels in demanding applications, the designer and end user experience improved toughness at low temperature, excellent fatigue resistance and fracture toughness and excellent weldability. These enhancements provide structural engineers the opportunity to further improve the pressure vessel design and performance. The Nb-microalloy alloy designs also result in reduced operational production cost at the steel operation, thereby embracing the value-added attribute Nb provides to both the producer and the end user throughout the supply chain. For example, through the adoption of these Nb-containing structural materials, several design-manufacturing companies are considering improved designs which offer improved manufacturability, lower overall cost and better life cycle performance.

Recent Advances in Metal Chalcogenides (MX; X = S, Se) Nanostructures for Electrochemical Supercapacitor Applications: A Brief Review

PubMed Central

Theerthagiri, Jayaraman; Durai, Govindarajan; Rana, Abu ul Hassan Sarwar; Sangeetha, Kirubanandam; Kuppusami, Parasuraman; Kim, Hyun-Seok

2018-01-01

Supercapacitors (SCs) have received a great deal of attention and play an important role for future self-powered devices, mainly owing to their higher power density. Among all types of electrical energy storage devices, electrochemical supercapacitors are considered to be the most promising because of their superior performance characteristics, including short charging time, high power density, safety, easy fabrication procedures, and long operational life. An SC consists of two foremost components, namely electrode materials, and electrolyte. The selection of appropriate electrode materials with rational nanostructured designs has resulted in improved electrochemical properties for high performance and has reduced the cost of SCs. In this review, we mainly spotlight the non-metallic oxide, especially metal chalcogenides (MX; X = S, Se) based nanostructured electrode materials for electrochemical SCs. Different non-metallic oxide materials are highlighted in various categories, such as transition metal sulfides and selenides materials. Finally, the designing strategy and future improvements on metal chalcogenide materials for the application of electrochemical SCs are also discussed. PMID:29671823

Amorphous Hole-Transporting Material based on 2,2'-Bis-substituted 1,1'-Biphenyl Scaffold for Application in Perovskite Solar Cells.

PubMed

Magomedov, Artiom; Sakai, Nobuya; Kamarauskas, Egidijus; Jokubauskaitė, Gabrielė; Franckevičius, Marius; Jankauskas, Vygintas; Snaith, Henry J; Getautis, Vytautas

2017-05-04

Perovskite solar cells are considered a promising technology for solar-energy conversion, with power conversion efficiencies currently exceeding 20 %. In most of the reported devices, Spiro-OMeTAD is used for positive-charge extraction and transport layer. Although a number of alternative hole-transporting materials with different aromatic or heteroaromatic fragments have already been synthesized, a cheap and well-performing hole-transporting material is still in high demand. In this work, a two-step synthesis of a carbazole-based hole-transporting material is presented. Synthesized compounds exhibited amorphous nature, good solubility and thermal stability. The perovskite solar cells employing the newly synthesized material generated a power conversion efficiency of 16.5 % which is slightly lower than that obtained with Spiro-OMeTAD (17.5 %). The low-cost synthesis and high performance makes our hole-transport material promising for applications in perovskite-based optoelectronic devices. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Advanced Nanostructured Anode Materials for Sodium-Ion Batteries.

PubMed

Wang, Qidi; Zhao, Chenglong; Lu, Yaxiang; Li, Yunming; Zheng, Yuheng; Qi, Yuruo; Rong, Xiaohui; Jiang, Liwei; Qi, Xinguo; Shao, Yuanjun; Pan, Du; Li, Baohua; Hu, Yong-Sheng; Chen, Liquan

2017-11-01

Sodium-ion batteries (NIBs), due to the advantages of low cost and relatively high safety, have attracted widespread attention all over the world, making them a promising candidate for large-scale energy storage systems. However, the inherent lower energy density to lithium-ion batteries is the issue that should be further investigated and optimized. Toward the grid-level energy storage applications, designing and discovering appropriate anode materials for NIBs are of great concern. Although many efforts on the improvements and innovations are achieved, several challenges still limit the current requirements of the large-scale application, including low energy/power densities, moderate cycle performance, and the low initial Coulombic efficiency. Advanced nanostructured strategies for anode materials can significantly improve ion or electron transport kinetic performance enhancing the electrochemical properties of battery systems. Herein, this Review intends to provide a comprehensive summary on the progress of nanostructured anode materials for NIBs, where representative examples and corresponding storage mechanisms are discussed. Meanwhile, the potential directions to obtain high-performance anode materials of NIBs are also proposed, which provide references for the further development of advanced anode materials for NIBs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An aqueous electrolyte, sodium ion functional, large format energy storage device for stationary applications

NASA Astrophysics Data System (ADS)

Whitacre, J. F.; Wiley, T.; Shanbhag, S.; Wenzhuo, Y.; Mohamed, A.; Chun, S. E.; Weber, E.; Blackwood, D.; Lynch-Bell, E.; Gulakowski, J.; Smith, C.; Humphreys, D.

2012-09-01

An approach to making large format economical energy storage devices based on a sodium-interactive set of electrodes in a neutral pH aqueous electrolyte is described. The economics of materials and manufacturing are examined, followed by a description of an asymmetric/hybrid device that has λ-MnO2 positive electrode material and low cost activated carbon as the negative electrode material. Data presented include materials characterization of the active materials, cyclic voltammetry, galvanostatic charge/discharge cycling, and application-specific performance of an 80 V, 2.4 kW h pack. The results indicate that this set of electrochemical couples is stable, low cost, requires minimal battery management control electronics, and therefore has potential for use in stationary applications where device energy density is not a concern.

Sustainable design and manufacturing of multifunctional polymer nanocomposite coatings: A multiscale systems approach

NASA Astrophysics Data System (ADS)

Xiao, Jie

Polymer nanocomposites have a great potential to be a dominant coating material in a wide range of applications in the automotive, aerospace, ship-making, construction, and pharmaceutical industries. However, how to realize design sustainability of this type of nanostructured materials and how to ensure the true optimality of the product quality and process performance in coating manufacturing remain as a mountaintop area. The major challenges arise from the intrinsic multiscale nature of the material-process-product system and the need to manipulate the high levels of complexity and uncertainty in design and manufacturing processes. This research centers on the development of a comprehensive multiscale computational methodology and a computer-aided tool set that can facilitate multifunctional nanocoating design and application from novel function envisioning and idea refinement, to knowledge discovery and design solution derivation, and further to performance testing in industrial applications and life cycle analysis. The principal idea is to achieve exceptional system performance through concurrent characterization and optimization of materials, product and associated manufacturing processes covering a wide range of length and time scales. Multiscale modeling and simulation techniques ranging from microscopic molecular modeling to classical continuum modeling are seamlessly coupled. The tight integration of different methods and theories at individual scales allows the prediction of macroscopic coating performance from the fundamental molecular behavior. Goal-oriented design is also pursued by integrating additional methods for bio-inspired dynamic optimization and computational task management that can be implemented in a hierarchical computing architecture. Furthermore, multiscale systems methodologies are developed to achieve the best possible material application towards sustainable manufacturing. Automotive coating manufacturing, that involves paint spay and curing, is specifically discussed in this dissertation. Nevertheless, the multiscale considerations for sustainable manufacturing, the novel concept of IPP control, and the new PPDE-based optimization method are applicable to other types of manufacturing, e.g., metal coating development through electroplating. It is demonstrated that the methodological development in this dissertation can greatly facilitate experimentalists in novel material invention and new knowledge discovery. At the same time, they can provide scientific guidance and reveal various new opportunities and effective strategies for sustainable manufacturing.

ZERODUR TAILORED for cryogenic application

NASA Astrophysics Data System (ADS)

Jedamzik, R.; Westerhoff, T.

2014-07-01

ZERODUR® glass ceramic from SCHOTT is known for its very low thermal expansion coefficient (CTE) at room temperature and its excellent CTE homogeneity. It is widely used for ground-based astronomical mirrors but also for satellite applications. Many reference application demonstrate the excellent and long lasting performance of ZERODUR® components in orbit. For space application a low CTE of the mirror material is required at cryogenic temperatures together with a good match of the thermal expansion to the supporting structure material. It is possible to optimize the coefficient of thermal expansion of ZERODUR® for cryogenic applications. This paper reports on measurements of thermal expansion of ZERODUR® down to cryogenic temperatures of 10 K performed by the PTB (Physikalisch Technische Bundesanstallt, Braunschweig, Germany, the national metrology laboratory). The ZERODUR® TAILORED CRYO presented in this paper has a very low coefficient of thermal expansion down to 70 K. The maximum absolute integrated thermal expansion down to 10 K is only about 20 ppm. Mirror blanks made from ZERODUR® TAILORED CRYO can be light weighted to almost 90% with our modern processing technologies. With ZERODUR® TAILORED CRYO, SCHOTT offers the mirror blank material for the next generation of space telescope applications.

Redox-active Hybrid Materials for Pseudocapacitive Energy Storage

NASA Astrophysics Data System (ADS)

Boota, Muhammad

Organic-inorganic hybrid materials show a great promise for the purpose of manufacturing high performance electrode materials for electrochemical energy storage systems and beyond. Molecular level combination of two best suited components in a hybrid material leads to new or sometimes exceptional sets of physical, chemical, mechanical and electrochemical properties that makes them attractive for broad ranges of applications. Recently, there has been growing interest in producing redox-active hybrid nanomaterials for energy storage applications where generally the organic component provides high redox capacitance and the inorganic component offers high conductivity and robust support. While organic-inorganic hybrid materials offer tremendous opportunities for electrochemical energy storage applications, the task of matching the right organic material out of hundreds of natural and nearly unlimited synthetic organic molecules to appropriate nanostructured inorganic support hampers their electrochemical energy storage applications. We aim to present the recent development of redox-active hybrid materials for pseudocapacitive energy storage. We will show the impact of combination of suitable organic materials with distinct carbon nanostructures and/or highly conductive metal carbides (MXenes) on conductivity, charge storage performance, and cyclability. Combined experimental and molecular simulation results will be discussed to shed light on the interfacial organic-inorganic interactions, pseudocapacitive charge storage mechanisms, and likely orientations of organic molecules on conductive supports. Later, the concept of all-pseudocapacitive organic-inorganic asymmetric supercapacitors will be highlighted which open up new avenues for developing inexpensive, sustainable, and high energy density aqueous supercapacitors. Lastly, future challenges and opportunities to further tailor the redox-active hybrids will be highlighted.

Nanostructured manganese oxide thin films as electrode material for supercapacitors

NASA Astrophysics Data System (ADS)

Xia, Hui; Lai, Man On; Lu, Li

2011-01-01

Electrochemical capacitors, also called supercapacitors, are alternative energy storage devices, particularly for applications requiring high power densities. Recently, manganese oxides have been extensively evaluated as electrode materials for supercapacitors due to their low cost, environmental benignity, and promising supercapacitive performance. In order to maximize the utilization of manganese oxides as the electrode material for the supercapacitors and improve their supercapacitive performance, the nanostructured manganese oxides have therefore been developed. This paper reviews the synthesis of the nanostructured manganese oxide thin films by different methods and the supercapacitive performance of different nanostructures.

Fabrication and characterization of joined silicon carbide cylindrical components for nuclear applications

NASA Astrophysics Data System (ADS)

Khalifa, H. E.; Deck, C. P.; Gutierrez, O.; Jacobsen, G. M.; Back, C. A.

2015-02-01

The use of silicon carbide (SiC) composites as structural materials in nuclear applications necessitates the development of a viable joining method. One critical application for nuclear-grade joining is the sealing of fuel within a cylindrical cladding. This paper demonstrates cylindrical joint feasibility using a low activation nuclear-grade joint material comprised entirely of β-SiC. While many papers have considered joining material, this paper takes into consideration the joint geometry and component form factor, as well as the material performance. Work focused specifically on characterizing the strength and permeability performance of joints between cylindrical SiC-SiC composites and monolithic SiC endplugs. The effects of environment and neutron irradiation were not evaluated in this study. Joint test specimens of different geometries were evaluated in their as-fabricated state, as well as after being subjected to thermal cycling and partial mechanical loading. A butted scarf geometry supplied the best combination of high strength and low permeability. A leak rate performance of 2 × 10-9 mbar l s-1 was maintained after thermal cycling and partial mechanical loading and sustained applied force of 3.4 kN, or an apparent strength of 77 MPa. This work shows that a cylindrical SiC-SiC composite tube sealed with a butted scarf endplug provides out-of-pile strength and permeability performance that meets light water reactor design requirements.

Deoxyribonucleic acid (DNA)-based optical materials

NASA Astrophysics Data System (ADS)

Grote, James G.; Heckman, Emily M.; Hagen, Joshua A.; Yaney, Perry P.; Subramanyam, Guru; Clarson, Stephen J.; Diggs, Darnell E.; Nelson, Robert L.; Zetts, John S.; Hopkins, F. Kenneth; Ogata, Naoya

2004-12-01

Optical materials for waveguiding applications must possess the desired optical and electromagnetic properties for optimal device performance. Purified deoxyribonucleic acid (DNA), derived from salmon sperm, has been investigated for use as an optical waveguide material. In this paper we present the materials processing and optical and electromagnetic characterization of this purified DNA to render a high quality, low loss optical waveguide material.

Industrial waste treatment and application in rubber production

NASA Astrophysics Data System (ADS)

Pugacheva, I. N.; Popova, L. V.; Repin, P. S.; Molokanova, L. V.

2018-03-01

The paper provides for the relevance of various industrial waste treatment and application, as well as their secondary commercialization. It considers treatment of secondary polymer materials turning to additives applied in rubber production, in particular, in production of conveyor and V-type belts used in mechanical engineering. It is found that oligomers obtained from petroleum by-products can be used as an impregnating compound for fiber materials. Such adhesive treatment prior to introduction of impregnating compounds into elastomeric materials improves adhesion and complements performance of obtained composites.

Design and Application of Integrated Assembly Technology of FRG in Residential Ceiling

NASA Astrophysics Data System (ADS)

Li, Xiuyun; Yu, Changyong

2018-06-01

FRG material is a new environmentally friendly indoor decoration materials and popular in prefabricated construction, the paper introduces the performance and design of materials, and takes FRG in the residential ceiling integrated assembly process into a demonstration project, which showed that FRG in the prefabricated modules integrated ceiling of the whole template scheme has a great artistry and application effect. Meanwhile it provides reference for the integrated ceiling assembly modular process design of similar indoor decoration.

Composite Material Application to Liquid Rocket Engines

NASA Technical Reports Server (NTRS)

Judd, D. C.

1982-01-01

The substitution of reinforced plastic composite (RPC) materials for metal was studied. The major objectives were to: (1) determine the extent to which composite materials can be beneficially used in liquid rocket engines; (2) identify additional technology requirements; and (3) determine those areas which have the greatest potential for return. Weight savings, fabrication costs, performance, life, and maintainability factors were considered. Two baseline designs, representative of Earth to orbit and orbit to orbit engine systems, were selected. Weight savings are found to be possible for selected components with the substitution of materials for metal. Various technology needs are identified before RPC material can be used in rocket engine applications.

Safer energetic materials by a nanotechnological approach.

PubMed

Siegert, Benny; Comet, Marc; Spitzer, Denis

2011-09-01

Energetic materials - explosives, thermites, populsive powders - are used in a variety of military and civilian applications. Their mechanical and electrostatic sensitivity is high in many cases, which can lead to accidents during handling and transport. These considerations limit the practical use of some energetic materials despite their good performance. For industrial applications, safety is one of the main criteria for selecting energetic materials. The sensitivity has been regarded as an intrinsic property of a substance for a long time. However, in recent years, several approaches to lower the sensitivity of a given substance, using nanotechnology and materials engineering, have been described. This feature article gives an overview over ways to prepare energetic (nano-)materials with a lower sensitivity.

High-performance colossal permittivity materials of (Nb + Er) co-doped TiO2 for large capacitors and high-energy-density storage devices.

PubMed

Tse, Mei-Yan; Wei, Xianhua; Hao, Jianhua

2016-09-21

The search for colossal permittivity (CP) materials is imperative because of their potential for promising applications in the areas of device miniaturization and energy storage. High-performance CP materials require high dielectric permittivity, low dielectric loss and relatively weak dependence of frequency- and temperature. In this work, we first investigate the CP behavior of rutile TiO2 ceramics co-doped with niobium and erbium, i.e., (Er0.5Nb0.5)xTi1-xO2. Excellent dielectric properties were observed in the materials, including a CP of up to 10(4)-10(5) and a low dielectric loss (tan δ) down to 0.03, which are lower than that of the previously reported co-doped TiO2 CP materials when measured at 1 kHz. Stabilities of frequency and temperature were also accomplished via doping Er and Nb. Valence states of the elements in the material were analyzed using X-ray photoelectron spectroscopy. The Er induced secondary phases were observed using elemental mapping and energy-dispersive spectrometry. Consequently, this work may provide comprehensive guidance to develop high-performance CP materials for fully solid-state capacitor and energy storage applications.

40 CFR 65.158 - Performance test procedures for control devices.

Code of Federal Regulations, 2012 CFR

2012-07-01

... loading period during which regulated materials are loaded, and samples shall be collected using... applicable. The regulated material concentration and percent reduction may be measured as either total regulated material or as TOC (minus methane and ethane) according to the procedures specified. (1) Method 1...

40 CFR 65.158 - Performance test procedures for control devices.

Code of Federal Regulations, 2013 CFR

2013-07-01

... loading period during which regulated materials are loaded, and samples shall be collected using... applicable. The regulated material concentration and percent reduction may be measured as either total regulated material or as TOC (minus methane and ethane) according to the procedures specified. (1) Method 1...

40 CFR 65.158 - Performance test procedures for control devices.

Code of Federal Regulations, 2014 CFR

2014-07-01

... loading period during which regulated materials are loaded, and samples shall be collected using... applicable. The regulated material concentration and percent reduction may be measured as either total regulated material or as TOC (minus methane and ethane) according to the procedures specified. (1) Method 1...

Evaluation of various fire retardants for use in wood flour--polyethylene composites

Treesearch

Nicole M. Stark; Robert H. White; Scott A. Mueller; Tim A. Osswald

2010-01-01

Wood-plastic composites represent a growing class of materials used by the residential construction industry and the furniture industry. For some applications in these industries, the fire performance of the material must be known, and in some cases improved. However, the fire performance of wood-plastic composites is not well understood, and there is little...

Highly crumpled solar reduced graphene oxide electrode for supercapacitor application

NASA Astrophysics Data System (ADS)

Mohanapriya, K.; Ahirrao, Dinesh J.; Jha, Neetu

2018-04-01

Highly crumpled solar reduced graphene oxide (CSRGO) was synthesized by simple and rapid method through freezing the solar reduced graphene oxide aqueous suspension using liquid nitrogen and used as electrode material for supercapacitor application. This electrode material was characterized by transmission electron microscope (TEM), X-Ray diffractometer (XRD) and Raman Spectroscopy techniques to understand the morphology and structure. The electrochemical performance was studied by cyclic voltammetry (CV), galvanostatic charge/discharge (CD) and electrochemical impedance spectroscopy (EIS) using 6M KOH electrolyte. The CSRGO exhibit high specifc capacitance of 210.1 F g-1 at the current density of 0.5 A g-1 and shows excellent rate capability. These features make the CSRGO material as promising electrode for high-performance supercapacitors.

A review of materials for spectral design coatings in signature management applications

NASA Astrophysics Data System (ADS)

Andersson, Kent E.; Škerlind, Christina

2014-10-01

The current focus in Swedish policy towards national security and high-end technical systems, together with a rapid development in multispectral sensor technology, adds to the utility of developing advanced materials for spectral design in signature management applications. A literature study was performed probing research databases for advancements. Qualitative text analysis was performed using a six-indicator instrument: spectrally selective reflectance; low gloss; low degree of polarization; low infrared emissivity; non-destructive properties in radar and in general controllability of optical properties. Trends are identified and the most interesting materials and coating designs are presented with relevant performance metrics. They are sorted into categories in the order of increasing complexity: pigments and paints, one-dimensional structures, multidimensional structures (including photonic crystals), and lastly biomimic and metamaterials. The military utility of the coatings is assessed qualitatively. The need for developing a framework for assessing the military utility of incrementally increasing the performance of spectrally selective coatings is identified.

High-performance supercapacitor electrode from cellulose-derived, inter-bonded carbon nanofibers

NASA Astrophysics Data System (ADS)

Cai, Jie; Niu, Haitao; Wang, Hongxia; Shao, Hao; Fang, Jian; He, Jingren; Xiong, Hanguo; Ma, Chengjie; Lin, Tong

2016-08-01

Carbon nanofibers with inter-bonded fibrous structure show high supercapacitor performance when being used as electrode materials. Their preparation is highly desirable from cellulose through a pyrolysis technique, because cellulose is an abundant, low cost natural material and its carbonization does not emit toxic substance. However, interconnected carbon nanofibers prepared from electrospun cellulose nanofibers and their capacitive behaviors have not been reported in the research literature. Here we report a facile one-step strategy to prepare inter-bonded carbon nanofibers from partially hydrolyzed cellulose acetate nanofibers, for making high-performance supercapacitors as electrode materials. The inter-fiber connection shows considerable improvement in electrode electrochemical performances. The supercapacitor electrode has a specific capacitance of ∼241.4 F g-1 at 1 A g-1 current density. It maintains high cycling stability (negligible 0.1% capacitance reduction after 10,000 cycles) with a maximum power density of ∼84.1 kW kg-1. They may find applications in the development of efficient supercapacitor electrodes for energy storage applications.

Nanomaterials derived from metal-organic frameworks

NASA Astrophysics Data System (ADS)

Dang, Song; Zhu, Qi-Long; Xu, Qiang

2018-01-01

The thermal transformation of metal-organic frameworks (MOFs) generates a variety of nanostructured materials, including carbon-based materials, metal oxides, metal chalcogenides, metal phosphides and metal carbides. These derivatives of MOFs have characteristics such as high surface areas, permanent porosities and controllable functionalities that enable their good performance in sensing, gas storage, catalysis and energy-related applications. Although progress has been made to tune the morphologies of MOF-derived structures at the nanometre scale, it remains crucial to further our knowledge of the relationship between morphology and performance. In this Review, we summarize the synthetic strategies and optimized methods that enable control over the size, morphology, composition and structure of the derived nanomaterials. In addition, we compare the performance of materials prepared by the MOF-templated strategy and other synthetic methods. Our aim is to reveal the relationship between the morphology and the physico-chemical properties of MOF-derived nanostructures to optimize their performance for applications such as sensing, catalysis, and energy storage and conversion.

Carbon Nanofibrous Materials from Electrospinning: Preparation and Energy Applications

NASA Astrophysics Data System (ADS)

Aboagye, Alex

Carbon nanofibers with diameters that fall into submicron and nanometer range have attracted growing attention in recent years due to their superior chemical, electrical, and mechanical properties in combination with their unique one-dimensional nanostructures. Unlike catalytic synthesis, electrospinning polyacrylonitrile (PAN) followed by stabilization and carbonization has become a straightforward and convenient route to make continuous carbon nanofibers. The overall objective of this research was the design and production fiber based carbon nanomaterials, investigation of their structures and use in functional applications. Specifically, these carbon nanofibrous materials were employed as electrode material for energy storage and conversion devices such as dye sensitized solar cells and supercapacitors Morphology and structure of the carbon nanofibrous materials were investigated and their performance in corresponding applications were evaluated.

Materials Analysis and Modeling of Underfill Materials.

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

Wyatt, Nicholas B; Chambers, Robert S.

2015-08-01

The thermal-mechanical properties of three potential underfill candidate materials for PBGA applications are characterized and reported. Two of the materials are a formulations developed at Sandia for underfill applications while the third is a commercial product that utilizes a snap-cure chemistry to drastically reduce cure time. Viscoelastic models were calibrated and fit using the property data collected for one of the Sandia formulated materials. Along with the thermal-mechanical analyses performed, a series of simple bi-material strip tests were conducted to comparatively analyze the relative effects of cure and thermal shrinkage amongst the materials under consideration. Finally, current knowledge gaps asmore » well as questions arising from the present study are identified and a path forward presented.« less

Selection Criteria for New Materials For Thermoelectric Applications

NASA Astrophysics Data System (ADS)

Tritt, T. M.

1997-11-01

Recently there has been renewed interest in materials for thermoelectric refrigeration and power generation applications.(Terry M. Tritt, Science, 272, 1276, 1996),(G. Mahan, B. Sales and J. Sharp, Physics Today, March 50, 42, 1997) We have established a multidisciplinary program within the Physics Department and in collaboration with the Chemistry Department at Clemson University. The focus of our research utilizes a broad understanding of solid state physics coupled with solid state chemistry to synthesize and fully characterize promising materials for their potential as the "next generation" thermoelectric materials. An introduction to thermoelectric materials and the criteria for their selection and potential for applications will be given. To be promising as a thermoelectric material, a material must have a high Seebeck coefficient, α, high electrical conductivity, σ, and a low thermal conductivity, λ. These parameters go into the materials dimensionless figure of merit ZT = α^2σT/λ. We will discuss these parameters in relation to this materials performance as a potential thermoelectric material. We will also discuss some of the materials that are currently being investigated in the program at Clemson University.

Qualification of niobium materials for superconducting radio frequency cavity applications: View of a condensed matter physicist

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

Roy, S. B., E-mail: sbroy@rrcat.gov.in; Myneni, G. R., E-mail: rao@jlab.org

2015-12-04

We address the issue of qualifications of the niobium materials to be used for superconducting radio frequency (SCRF) cavity fabrications, from the point of view of a condensed matter physicist/materials scientist. We focus on the particular materials properties of niobium required for the functioning a SCRF cavity, and how to optimize the same properties for the best SCRF cavity performance in a reproducible manner. In this way the niobium materials will not necessarily be characterized by their purity alone, but in terms of those materials properties, which will define the limit of the SCRF cavity performance and also other relatedmore » material properties, which will help to sustain this best SCRF cavity performance. Furthermore we point out the need of standardization of the post fabrication processing of the niobium-SCRF cavities, which does not impair the optimized superconducting and thermal properties of the starting niobium-materials required for the reproducible performance of the SCRF cavities according to the design values.« less

Multi-layered poly-dimethylsiloxane as a non-hermetic packaging material for medical MEMS.

PubMed

Lachhman, S; Zorman, C A; Ko, W H

2012-01-01

Poly-dimethylsiloxane (PDMS) is an attractive material for packaging implantable biomedical microdevices owing to its biocompatibility, ease in application, and bio-friendly mechanical properties. Unfortunately, devices encapsulated solely by PDMS lack the longevity for use in chronic implant applications due to defect-related moisture penetration through the packaging layer caused by conventional deposition processes such as spin coating. This paper describes an effort to improve the performance of PDMS as a packaging material by constructing the encapsulant from multiple, thin roller casted layers of PDMS as a part of a polymeric multi-material package.

Application of a high-energy-density permanent magnet material in underwater systems

NASA Astrophysics Data System (ADS)

Cho, C. P.; Egan, C.; Krol, W. P.

1996-06-01

This paper addresses the application of high-energy-density permanent magnet (PM) technology to (1) the brushless, axial-field PM motor and (2) the integrated electric motor/pump system for under-water applications. Finite-element analysis and lumped parameter magnetic circuit analysis were used to calculate motor parameters and performance characteristics and to conduct tradeoff studies. Compact, efficient, reliable, and quiet underwater systems are attainable with the development of high-energy-density PM material, power electronic devices, and power integrated-circuit technology.

The implications and applications of nanotechnology in dentistry: A review.

PubMed

AlKahtani, Rawan N

2018-04-01

The emerging science of nanotechnology, especially within the dental and medical fields, sparked a research interest in their potential applications and benefits in comparison to conventional materials used. Therefore, a better understanding of the science behind nanotechnology is essential to appreciate how these materials can be utilised in our daily practice. The present paper will help the reader understand nanoscience, and the benefits and limitations of nanotechnology by addressing its ethical, social, and health implications. Additionally, nano-applications in dental diagnostics, dental prevention, and in dental materials will be addressed, with examples of commercially available products and evidence on their clinical performance.

Microgravity

NASA Image and Video Library

1999-11-10

Space Vacuum Epitaxy Center works with industry and government laboratories to develop advanced thin film materials and devices by utilizing the most abundant free resource in orbit: the vacuum of space. SVEC, along with its affiliates, is developing semiconductor mid-IR lasers for environmental sensing and defense applications, high efficiency solar cells for space satellite applications, oxide thin films for computer memory applications, and ultra-hard thin film coatings for wear resistance in micro devices. Performance of these vacuum deposited thin film materials and devices can be enhanced by using the ultra-vacuum of space for which SVEC has developed the Wake Shield Facility---a free flying research platform dedicated to thin film materials development in space.

Microgravity

NASA Image and Video Library

2000-11-10

Space Vacuum Epitaxy Center works with industry and government laboratories to develop advanced thin film materials and devices by utilizing the most abundant free resource in orbit: the vacuum of space. SVEC, along with its affiliates, is developing semiconductor mid-IR lasers for environmental sensing and defense applications, high efficiency solar cells for space satellite applications, oxide thin films for computer memory applications, and ultra-hard thin film coatings for wear resistance in micro devices. Performance of these vacuum deposited thin film materials and devices can be enhanced by using the ultra-vacuum of space for which SVEC has developed the Wake Shield Facility---a free flying research platform dedicated to thin film materials development in space.

Acoustic Absorption in Porous Materials

NASA Technical Reports Server (NTRS)

Kuczmarski, Maria A.; Johnston, James C.

2011-01-01

An understanding of both the areas of materials science and acoustics is necessary to successfully develop materials for acoustic absorption applications. This paper presents the basic knowledge and approaches for determining the acoustic performance of porous materials in a manner that will help materials researchers new to this area gain the understanding and skills necessary to make meaningful contributions to this field of study. Beginning with the basics and making as few assumptions as possible, this paper reviews relevant topics in the acoustic performance of porous materials, which are often used to make acoustic bulk absorbers, moving from the physics of sound wave interactions with porous materials to measurement techniques for flow resistivity, characteristic impedance, and wavenumber.

Food Stamps. Learning Packet No. 2.

ERIC Educational Resources Information Center

American Bar Association, Washington, DC. Clearinghouse for Offender Literacy Programs.

This package of instructional materials is designed to aid adults in prison to perform the functional skill of applying for food stamps. The materials consist of instructions for teachers, a sample application for food stamps, a student's work sheet and answer sheet, vocabulary flash cards, and resource materials on food stamps. (MKM)

Metal-Organic Framework-Derived Nanoporous Metal Oxides toward Supercapacitor Applications: Progress and Prospects.

PubMed

Salunkhe, Rahul R; Kaneti, Yusuf V; Yamauchi, Yusuke

2017-06-27

Transition metal oxides (TMOs) have attracted significant attention for energy storage applications such as supercapacitors due to their good electrical conductivity, high electrochemical response (by providing Faradaic reactions), low manufacturing costs, and easy processability. Despite exhibiting these attractive characteristics, the practical applications of TMOs for supercapacitors are still relatively limited. This is largely due to their continuous Faradaic reactions, which can lead to major changes or destruction of their structure as well phase changes (in some cases) during cycling, leading to the degradation in their capacitive performance over time. Hence, there is an immediate need to develop new synthesis methods, which will readily provide stable porous architectures, controlled phase, as well as useful control over dimensions (1-D, 2-D, and 3-D) of the metal oxides for improving their performance in supercapacitor applications. Since its discovery in late 1990s, metal-organic frameworks (MOFs) have influenced many fields of material science. In recent years, they have gained significant attention as precursors or templates for the derivation of porous metal oxide nanostructures and nanocomposites for next-generation supercapacitor applications. Even though these materials have widespread applications and have been widely studied in terms of their structural features and synthesis, it is still not clear how these materials will play an important role in the development of the supercapacitor field. In this review, we will summarize the recent developments in the field of MOF-derived porous metal oxide nanostructures and nanocomposites for supercapacitor applications. Furthermore, the current challenges along with the future trends and prospects in the application of these materials for supercapacitors will also be discussed.

Integrated Computational Materials Engineering Development of Alternative Cu-Be Alloys

DTIC Science & Technology

2012-08-01

Be alloy replacement in highly loaded wear applications . ● Development bushing designs for the enhancement of dynamic wear performance...Material Properties and Tribological Characterization Cu-Based and Co- Based Alloy Concept Selection Requirements Definition Bushing Design and...properties and cost for highly loaded bushing applications ● QuesTek’s NAVAIR-funded SBIR Phase II program demonstrated the feasibility of designing Be-free

Advanced high-temperature thermal energy storage media for industrial applications

NASA Astrophysics Data System (ADS)

Clear, T. D.; Weibel, R. T.

An advanced thermal energy storage (TES) media concept based on use of carbonate salt/ceramic composite materials is being developed for industrial process and reject heat applications. This paper describes the composite latent/sensible media concept and its potential advantages over state-of-the-art latent heat systems. Media stability requirements, on-going materials development efforts and planned TES performance evaluation tests are discussed.

Advanced high-temperature thermal energy storage media for industrial applications

NASA Astrophysics Data System (ADS)

Claar, T. D.; Waibel, R. T.

1982-02-01

An advanced thermal energy storage media concept based on use of carbonate salt/ceramic composite materials is being developed for industrial process and reject heat applications. The composite latent/sensible media concept and its potential advantages over state of the art latent heat systems is described. Media stability requirements, on-going materials development efforts, and planned thermal energy storage (TES) performance evaluation tests are discussed.

Spectromicroscopy and coherent diffraction imaging: focus on energy materials applications.

PubMed

Hitchcock, Adam P; Toney, Michael F

2014-09-01

Current and future capabilities of X-ray spectromicroscopy are discussed based on coherence-limited imaging methods which will benefit from the dramatic increase in brightness expected from a diffraction-limited storage ring (DLSR). The methods discussed include advanced coherent diffraction techniques and nanoprobe-based real-space imaging using Fresnel zone plates or other diffractive optics whose performance is affected by the degree of coherence. The capabilities of current systems, improvements which can be expected, and some of the important scientific themes which will be impacted are described, with focus on energy materials applications. Potential performance improvements of these techniques based on anticipated DLSR performance are estimated. Several examples of energy sciences research problems which are out of reach of current instrumentation, but which might be solved with the enhanced DLSR performance, are discussed.

Structural materials for Gen-IV nuclear reactors: Challenges and opportunities

NASA Astrophysics Data System (ADS)

Murty, K. L.; Charit, I.

2008-12-01

Generation-IV reactor design concepts envisioned thus far cater toward a common goal of providing safer, longer lasting, proliferation-resistant and economically viable nuclear power plants. The foremost consideration in the successful development and deployment of Gen-IV reactor systems is the performance and reliability issues involving structural materials for both in-core and out-of-core applications. The structural materials need to endure much higher temperatures, higher neutron doses and extremely corrosive environment, which are beyond the experience of the current nuclear power plants. Materials under active consideration for use in different reactor components include various ferritic/martensitic steels, austenitic stainless steels, nickel-base superalloys, ceramics, composites, etc. This paper presents a summary of various Gen-IV reactor concepts, with emphasis on the structural materials issues depending on the specific application areas. This paper also discusses the challenges involved in using the existing materials under both service and off-normal conditions. Tasks become increasingly complex due to the operation of various fundamental phenomena like radiation-induced segregation, radiation-enhanced diffusion, precipitation, interactions between impurity elements and radiation-produced defects, swelling, helium generation and so forth. Further, high temperature capability (e.g. creep properties) of these materials is a critical, performance-limiting factor. It is demonstrated that novel alloy and microstructural design approaches coupled with new materials processing and fabrication techniques may mitigate the challenges, and the optimum system performance may be achieved under much demanding conditions.

Cost-Efficient Storage of Cryogens

NASA Technical Reports Server (NTRS)

Fesmire, J. E.; Sass, J. P.; Nagy, Z.; Sojoumer, S. J.; Morris, D. L.; Augustynowicz, S. D.

2007-01-01

NASA's cryogenic infrastructure that supports launch vehicle operations and propulsion testing is reaching an age where major refurbishment will soon be required. Key elements of this infrastructure are the large double-walled cryogenic storage tanks used for both space vehicle launch operations and rocket propulsion testing at the various NASA field centers. Perlite powder has historically been the insulation material of choice for these large storage tank applications. New bulk-fill insulation materials, including glass bubbles and aerogel beads, have been shown to provide improved thermal and mechanical performance. A research testing program was conducted to investigate the thermal performance benefits as well as to identify operational considerations and associated risks associated with the application of these new materials in large cryogenic storage tanks. The program was divided into three main areas: material testing (thermal conductivity and physical characterization), tank demonstration testing (liquid nitrogen and liquid hydrogen), and system studies (thermal modeling, economic analysis, and insulation changeout). The results of this research work show that more energy-efficient insulation solutions are possible for large-scale cryogenic storage tanks worldwide and summarize the operational requirements that should be considered for these applications.

New evaluation parameter for wearable thermoelectric generators

NASA Astrophysics Data System (ADS)

Wijethunge, Dimuthu; Kim, Woochul

2018-04-01

Wearable devices constitute a key application area for thermoelectric devices. However, owing to new constraints in wearable applications, a few conventional device optimization techniques are not appropriate and material evaluation parameters, such as figure of merit (zT) and power factor (PF), tend to be inadequate. We illustrated the incompleteness of zT and PF by performing simulations and considering different thermoelectric materials. The results indicate a weak correlation between device performance and zT and PF. In this study, we propose a new evaluation parameter, zTwearable, which is better suited for wearable applications compared to conventional zT. Owing to size restrictions, gap filler based device optimization is extremely critical in wearable devices. With respect to the occasions in which gap fillers are used, expressions for power, effective thermal conductivity (keff), and optimum load electrical ratio (mopt) are derived. According to the new parameters, the thermal conductivity of the material has become much more critical now. The proposed new evaluation parameter, namely, zTwearable, is extremely useful in the selection of an appropriate thermoelectric material among various candidates prior to the commencement of the actual design process.

Recent Progress in Synthesis and Application of Low-Dimensional Silicon Based Anode Material for Lithium Ion Battery

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

Sun, Yuandong; Liu, Kewei; Zhu, Yu

Silicon is regarded as the next generation anode material for LIBs with its ultra-high theoretical capacity and abundance. Nevertheless, the severe capacity degradation resulting from the huge volume change and accumulative solid-electrolyte interphase (SEI) formation hinders the silicon based anode material for further practical applications. Hence, a variety of methods have been applied to enhance electrochemical performances in terms of the electrochemical stability and rate performance of the silicon anodes such as designing nanostructured Si, combining with carbonaceous material, exploring multifunctional polymer binders, and developing artificial SEI layers. Silicon anodes with low-dimensional structures (0D, 1D, and 2D), compared with bulkymore » silicon anodes, are strongly believed to have several advanced characteristics including larger surface area, fast electron transfer, and shortened lithium diffusion pathway as well as better accommodation with volume changes, which leads to improved electrochemical behaviors. Finally, in this review, recent progress of silicon anode synthesis methodologies generating low-dimensional structures for lithium ion batteries (LIBs) applications is listed and discussed.« less

Recent Progress in Synthesis and Application of Low-Dimensional Silicon Based Anode Material for Lithium Ion Battery

DOE PAGES

Sun, Yuandong; Liu, Kewei; Zhu, Yu

2017-07-31

Silicon is regarded as the next generation anode material for LIBs with its ultra-high theoretical capacity and abundance. Nevertheless, the severe capacity degradation resulting from the huge volume change and accumulative solid-electrolyte interphase (SEI) formation hinders the silicon based anode material for further practical applications. Hence, a variety of methods have been applied to enhance electrochemical performances in terms of the electrochemical stability and rate performance of the silicon anodes such as designing nanostructured Si, combining with carbonaceous material, exploring multifunctional polymer binders, and developing artificial SEI layers. Silicon anodes with low-dimensional structures (0D, 1D, and 2D), compared with bulkymore » silicon anodes, are strongly believed to have several advanced characteristics including larger surface area, fast electron transfer, and shortened lithium diffusion pathway as well as better accommodation with volume changes, which leads to improved electrochemical behaviors. Finally, in this review, recent progress of silicon anode synthesis methodologies generating low-dimensional structures for lithium ion batteries (LIBs) applications is listed and discussed.« less

Preparation and Application of Electrodes in Capacitive Deionization (CDI): a State-of-Art Review.

PubMed

Jia, Baoping; Zhang, Wei

2016-12-01

As a promising desalination technology, capacitive deionization (CDI) have shown practicality and cost-effectiveness in brackish water treatment. Developing more efficient electrode materials is the key to improving salt removal performance. This work reviewed current progress on electrode fabrication in application of CDI. Fundamental principal (e.g. EDL theory and adsorption isotherms) and process factors (e.g. pore distribution, potential, salt type and concentration) of CDI performance were presented first. It was then followed by in-depth discussion and comparison on properties and fabrication technique of different electrodes, including carbon aerogel, activated carbon, carbon nanotubes, graphene and ordered mesoporous carbon. Finally, polyaniline as conductive polymer and its potential application as CDI electrode-enhancing materials were also discussed.

Cost projections for Redox Energy storage systems

NASA Technical Reports Server (NTRS)

Michaels, K.; Hall, G.

1980-01-01

A preliminary design and system cost analysis was performed for the redox energy storage system. A conceptual design and cost estimate was prepared for each of two energy applications: (1) electric utility 100-MWh requirement (10-MW for ten hours) for energy storage for utility load leveling application, and (2) a 500-kWh requirement (10-kW for 50 hours) for use with a variety of residential or commercial applications, including stand alone solar photovoltaic systems. The conceptual designs were based on cell performance levels, system design parameters, and special material costs. These data were combined with estimated thermodynamic and hydraulic analysis to provide preliminary system designs. Results indicate that the redox cell stack to be amenable to mass production techniques with a relatively low material cost.

Preparation and thermal insulation performance of cast-in-situ phosphogypsum wall.

PubMed

Li, Yubo; Dai, Shaobin; Zhang, Yichao; Huang, Jun; Su, Ying; Ma, Baoguo

2018-01-01

The mass accumulation of phosphogypsum has caused serious environmental pollution, which has become a worldwide problem. Gypsum is a kind of green building material, which is lighter, has better heat and sound insulation performance, and is easier to recycle compared to cement. The application of cast-in-situ phosphogypsum wall could consume a large amount of pollutant, and improve the efficiency of building construction. The preparation and thermal insulation performance of cast-in-situ phosphogypsum wall were investigated. The property of phosphogypsum-fly ash-lime (PFL) triad cementing materials, the adaptability of retarders and superplasticizers, and the influences of vitrified microsphere as aggregates were explored. Thus, the optimum mix was proposed. Thermal insulation performance tests and ANSYS simulation of this material was carried out. Optimal structures based on heat channels and the method of calculation determining related parameters were proposed, which achieved a 12.3% reduction in the heat transfer coefficient of the wall. With good performance, phosphogypsum could be used in cast-in-situ walls. This paper provides the theoretical basis for the preparation and energy-saving application of phosphogypsum in the walls of buildings.

REVIEW OF MECHANISTIC UNDERSTANDING AND MODELING AND UNCERTAINTY ANALYSIS METHODS FOR PREDICTING CEMENTITIOUS BARRIER PERFORMANCE

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

Langton, C.; Kosson, D.

2009-11-30

Cementitious barriers for nuclear applications are one of the primary controls for preventing or limiting radionuclide release into the environment. At the present time, performance and risk assessments do not fully incorporate the effectiveness of engineered barriers because the processes that influence performance are coupled and complicated. Better understanding the behavior of cementitious barriers is necessary to evaluate and improve the design of materials and structures used for radioactive waste containment, life extension of current nuclear facilities, and design of future nuclear facilities, including those needed for nuclear fuel storage and processing, nuclear power production and waste management. The focusmore » of the Cementitious Barriers Partnership (CBP) literature review is to document the current level of knowledge with respect to: (1) mechanisms and processes that directly influence the performance of cementitious materials (2) methodologies for modeling the performance of these mechanisms and processes and (3) approaches to addressing and quantifying uncertainties associated with performance predictions. This will serve as an important reference document for the professional community responsible for the design and performance assessment of cementitious materials in nuclear applications. This review also provides a multi-disciplinary foundation for identification, research, development and demonstration of improvements in conceptual understanding, measurements and performance modeling that would be lead to significant reductions in the uncertainties and improved confidence in the estimating the long-term performance of cementitious materials in nuclear applications. This report identifies: (1) technology gaps that may be filled by the CBP project and also (2) information and computational methods that are in currently being applied in related fields but have not yet been incorporated into performance assessments of cementitious barriers. The various chapters contain both a description of the mechanism or and a discussion of the current approaches to modeling the phenomena.« less

Outline of CS application experiments

NASA Astrophysics Data System (ADS)

Otsu, Y.; Kondoh, K.; Matsumoto, M.

1985-09-01

To promote and investigate the practical application of satellite use, CS application experiments for various social activity needs, including those of public services such as the National Police Agency and the Japanese National Railway, computer network services, news material transmissions, and advanced teleconference activities, were performed. Public service satellite communications systems were developed and tested. Based on results obtained, several public services have implemented CS-2 for practical disaster-back-up uses. Practical application computer network and enhanced video-conference experiments have also been performed.

Optical silicones for use in harsh operating environments

NASA Astrophysics Data System (ADS)

Riegler, Bill; Bruner, Stephen J.; Elgin, Randall

2004-12-01

The optics industry widely uses silcones for various fiber optic cable potting applications and light emitting diode protection. Optics manufacturers know traditional silicone elastomers, gels, thixotropic gels, and fluids not only perform extremely well in high temperature applications, but also offer refractive index matching so that silicones can transmit light with admirable efficiency. However, because environmental conditions may affect a material's performance over time, one must also consider the conditions the device operates in to ensure long-term reliability. External environments may include exposure to a combination of UV light and temperature, while other environments may expose devices to hydrocarbon based fuels. This paper will delve into the chemistry of silicones and functional groups that lend themselves to properties such as temperature, fuel, and radiation resistance to show shy silicone is the material of choice for optic applications under normally harmful forms of exposure. Data will be presented to examine silicone's performance in these environment.

High-performance indium gallium phosphide/gallium arsenide heterojunction bipolar transistors

NASA Astrophysics Data System (ADS)

Ahmari, David Abbas

Heterojunction bipolar transistors (HBTs) have demonstrated the high-frequency characteristics as well as the high linearity, gain, and power efficiency necessary to make them attractive for a variety of applications. Specific applications for which HBTs are well suited include amplifiers, analog-to-digital converters, current sources, and optoelectronic integrated circuits. Currently, most commercially available HBT-based integrated circuits employ the AlGaAs/GaAs material system in applications such as a 4-GHz gain block used in wireless phones. As modern systems require higher-performance and lower-cost devices, HBTs utilizing the newer, InGaP/GaAs and InP/InGaAs material systems will begin to dominate the HBT market. To enable the widespread use of InGaP/GaAs HBTs, much research on the fabrication, performance, and characterization of these devices is required. This dissertation will discuss the design and implementation of high-performance InGaP/GaAs HBTs as well as study HBT device physics and characterization.

Fabrication of Cu2 O-based Materials for Lithium-Ion Batteries.

PubMed

Zhang, Li; Li, Qinyuan; Xue, Huaiguo; Pang, Huan

2018-05-25

The improvement of the performance of advanced batteries has played a key role in the energy research community since its inception. Therefore, it is necessary to explore high-performance materials for applications in advanced batteries. Among the variety of materials applied in batteries, much research has been dedicated to examine cuprous oxide materials as working electrodes in lithium cells to check their suitability as anodes for Li-ion cells and this has revealed great working capacities because of their specific characteristics (polymorphic forms, controllable structure, high cycling capacity, etc.). Thus, cuprous oxide and its composites will be fully introduced in this Review for their applications in advanced batteries. It is believed that, in the future, both the study and the impact of cuprous oxide and its composites will be much more profound and lasting. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mechanical and durability characteristics of externally GFRP reinforced unsaturated polyester polymer concrete

NASA Astrophysics Data System (ADS)

Bouguessir, H.; Harkati, E.; Rokbi, M.; Priniotakis, G.; Vassiliadis, S.

2017-10-01

The last decades of the XXe century cognized a huge extent of composite materials uses to almost all everyday life’s applications, replacing the conventional materials, due to their outstanding properties especially highest strength-to-weight ratio and the ability to be designed to satisfy specific performance requirements. To get the most out of these wonder materials, a new concept, combining polymer concrete and composite laminates, is currently used in Algeria. This research work has the aim to investigate applicability of this concept in civil engineering through tensile and bending tests. On the other hand, the influence of various chemicals (Sodium hydroxide, Potassium Hydroxide and Calcium Carbonates) on our material and its tensile properties retention over long-time exposure was examined. The mechanical properties obtained indicate the convenience of this material for use in civil engineering thanks to its very good tensile and flexural performances in addition to its sufficient residual strength after theoretically 56 years.

Laser-assisted manufacturing of super-insulation materials

NASA Astrophysics Data System (ADS)

Wang, Zhen; Zhang, Tao; Park, Byung Kyu; Lee, Woo Il; Hwang, David

2017-02-01

Being lightweight materials with good mechanical and thermal properties, hollow glass micro-particles (HGMPs) have been widely studied for multiple applications. In this study, it is shown that by using reduced binder fraction diluted in solvent, enables minimal contacts among the HGMPs assisted by a natural capillary trend, as confirmed by optical and electron microscope imaging. Such material architecture fabricated in a composite level proves to have enhanced thermal insulation performance through quantitative thermal conductivity measurement. Mechanical strength has also been evaluated in terms of particle-binder bonding by tensile test via in-situ microscope inspection. Effect of laser treatment was examined for further improvement of thermal and mechanical properties by selective binder removal and efficient redistribution of remaining binder components. The fabricated composite materials have potential applications to building insulation materials for their scalable manufacturing nature, improved thermal insulation performance and reasonable mechanical strength. Further studies are needed to understand mechanical and thermal properties of the resulting composites, and key fabrication mechanisms involved with laser treatment of complex multi-component and multi-phase systems.

Recent developments in melt processed Gd-123 and MgB2 materials at RTRI

NASA Astrophysics Data System (ADS)

Muralidhar, M.; Fukumoto, Y.; Ishihara, A.; Suzuki, K.; Tomita, M.; Koblischka, M. R.; Yamamoto, A.; Kishio, K.

2014-01-01

In this contribution we will report on the current status, recent developments in GdBa2Cu3Oy "Gd-123" and MgB2 material processing, characterization, and applications at the Railway Technical Research Institute (RTRI). Batch-processing of Gd-123 bulk material grown in air was performed using novel thin film Nd-123 seeds grown on MgO crystals. In this way, we are able to fabricate materials with good quality, and uniform performance. We examined the technology of the uniform performance of the large 45 mm diameter, single grain Gd-123 bulks for use in application of NMR. For this purpose, four 5 mm thick pieces are cut vertically from a single grain Gd-123 material and the magnetic field distribution is measured using a scanning hall sensor. We found that all four pieces are single domain and exhibit a quite uniform field distribution. Furthermore, the batch-processed bulk materials are used for the construction of a chilled Maglev vehicle. On the other hand, to optimize the trapped field performance of bulk MgB2 material, several samples were prepared by solid state reaction at different temperatures ranging from 750 to 950 °C in pure argon atmosphere. X-ray diffraction results indicated that single phase and homogenous MgB2 bulks are produced when sintering them around 775 °C. Further, atomic force microscopy (AFM) and scanning electron microscopy (SEM) indicated that an uniform grain size results by controlling the processing temperature. So, higher trapped fields can be achieved in sintered MgB2 material.

A Mini Review: Can Graphene Be a Novel Material for Perovskite Solar Cell Applications?

NASA Astrophysics Data System (ADS)

Lim, Eng Liang; Yap, Chi Chin; Jumali, Mohammad Hafizuddin Hj; Teridi, Mohd Asri Mat; Teh, Chin Hoong

2018-06-01

Perovskite solar cells (PSCs) have raised research interest in scientific community because their power conversion efficiency is comparable to that of traditional commercial solar cells (i.e., amorphous Si, GaAs, and CdTe). Apart from that, PSCs are lightweight, are flexible, and have low production costs. Recently, graphene has been used as a novel material for PSC applications due to its excellent optical, electrical, and mechanical properties. The hydrophobic nature of graphene surface can provide protection against air moisture from the surrounding medium, which can improve the lifetime of devices. Herein, we review recent developments in the use of graphene for PSC applications as a conductive electrode, carrier transporting material, and stabilizer material. By exploring the application of graphene in PSCs, a new class of strategies can be developed to improve the device performance and stability before it can be commercialized in the photovoltaic market in the near future.

Composites Materials and Manufacturing Technologies for Space Applications

NASA Technical Reports Server (NTRS)

Vickers, J. H.; Tate, L. C.; Gaddis, S. W.; Neal, R. E.

2016-01-01

Composite materials offer significant advantages in space applications. Weight reduction is imperative for deep space systems. However, the pathway to deployment of composites alternatives is problematic. Improvements in the materials and processes are needed, and extensive testing is required to validate the performance, qualify the materials and processes, and certify components. Addressing these challenges could lead to the confident adoption of composites in space applications and provide spin-off technical capabilities for the aerospace and other industries. To address the issues associated with composites applications in space systems, NASA sponsored a Technical Interchange Meeting (TIM) entitled, "Composites Materials and Manufacturing Technologies for Space Applications," the proceedings of which are summarized in this Conference Publication. The NASA Space Technology Mission Directorate and the Game Changing Program chartered the meeting. The meeting was hosted by the National Center for Advanced Manufacturing (NCAM)-a public/private partnership between NASA, the State of Louisiana, Louisiana State University, industry, and academia, in association with the American Composites Manufacturers Association. The Louisiana Center for Manufacturing Sciences served as the coordinator for the TIM.

Low thrust chemical rocket technology

NASA Technical Reports Server (NTRS)

Schneider, Steven J.

1992-01-01

An on-going technology program to improve the performance of low thrust chemical rockets for spacecraft on-board propulsion applications is reviewed. Improved performance and lifetime is sought by the development of new predictive tools to understand the combustion and flow physics, introduction of high temperature materials and improved component designs to optimize performance, and use of higher performance propellants. Improved predictive technology is sought through the comparison of both local and global predictions with experimental data. Predictions are based on both the RPLUS Navier-Stokes code with finite rate kinetics and the JANNAF methodology. Data were obtained with laser-based diagnostics along with global performance measurements. Results indicate that the modeling of the injector and the combustion process needs improvement in these codes and flow visualization with a technique such as 2-D laser induced fluorescence (LIF) would aid in resolving issues of flow symmetry and shear layer combustion processes. High temperature material fabrication processes are under development and small rockets are being designed, fabricated, and tested using these new materials. Rhenium coated with iridium for oxidation protection was produced by the Chemical Vapor Deposition (CVD) process and enabled an 800 K increase in rocket operating temperature. Performance gains with this material in rockets using Earth storable propellants (nitrogen tetroxide and monomethylhydrazine or hydrazine) were obtained through component redesign to eliminate fuel film cooling and its associated combustion inefficiency while managing head end thermal soakback. Material interdiffusion and oxidation characteristics indicated that the requisite lifetimes of tens of hours were available for thruster applications. Rockets were designed, fabricated, and tested with thrusts of 22, 62, 440 and 550 N. Performance improvements of 10 to 20 seconds specific impulse were demonstrated. Higher performance propellants were evaluated: Space storable propellants, including liquid oxygen (LOX) as the oxidizer with nitrogen hydrides or hydrocarbon as fuels. Specifically, a LOX/hydrazine engine was designed, fabricated, and shown to have a 95 pct theoretical c-star which translates into a projected vacuum specific impulse of 345 seconds at an area ratio of 204:1. Further performance improvment can be obtained by the use of LOX/hydrogen propellants, especially for manned spacecraft applications, and specific designs must be developed and advanced through flight qualification.

Vacuum/Zero Net-Gravity Application for On-Orbit TPS Tile Repair

NASA Technical Reports Server (NTRS)

Harvey, Gale A.; Humes, Donald H.; Siochi, Emilie J.

2004-01-01

The Orbiter Columbia catastrophically failed during reentry February 1, 2003. All Space Shuttle flights were suspended, including logistics support for the International Space Station. NASA Langley Research Center s (LaRC) Structures and Materials Competency is performing characterizations of candidate materials for on-orbit repair of orbiter Thermal Protection System (TPS) tiles to support Return-to-Flight activities led by Johnson Space Center (JSC). At least ten materials properties or attributes (adhesion to damage site, thermal protection, char/ash strength, thermal expansion, blistering, flaming, mixing ease, application in vacuum and zero gravity, cure time, shelf or storage life, and short-term outgassing and foaming) of candidate materials are of interest for on-orbit repair. This paper reports application in vacuum and zero net-gravity (for viscous flow repair materials). A description of the test apparatus and preliminary results of several candidate materials are presented. The filling of damage cavities is different for some candidate repair materials in combined vacuum and zero net-gravity than in either vacuum or zero net-gravity alone.

Vacuum/Zero Net-Gravity Application for On-Orbit TPS Tile Repair

NASA Technical Reports Server (NTRS)

Harvey, Gale A.; Humes, Donald H.; Siochi, Emilie J.

2004-01-01

The Orbiter Columbia catastrophically failed during reentry February 1, 2003. All space Shuttle flights were suspended, including logistics support for the International Space Station. NASA LaRC s Structures and Materials Competency is performing characterizations of candidate materials for on-orbit repair of orbiter Thermal Protection System (TPS) tiles to support Return-to-Flight activities led by JSC. At least ten materials properties or attributes (adhesion to damage site, thermal protection, char/ash strength, thermal expansion, blistering, flaming, mixing ease, application in vacuum and zero gravity, cure time, shelf or storage life, and short-term outgassing and foaming) of candidate materials are of interest for on-orbit repair. This paper reports application in vacuum and zero net-gravity (for viscous flow repair materials). A description of the test apparatus and preliminary results of several candidate materials are presented. The filling of damage cavities is different for some candidate repair materials in combined vacuum and zero net-gravity than in either vacuum or zero net- gravity alone.

High Thermoelectric Performance by Convergence of Bands in IV-VI Semiconductors, Heavily Doped PbTe, and Alloys/Nanocomposites

NASA Technical Reports Server (NTRS)

Snyder, G. Jeffrey (Inventor); Pei, Yanzhong (Inventor)

2015-01-01

The present invention teaches an effective mechanism for enhancing thermoelectric performance through additional conductive bands. Using heavily doped p-PbTe materials as an example, a quantitative explanation is disclosed, as to why and how these additional bands affect the figure of merit. A high zT of approaching 2 at high temperatures makes these simple, likely more stable (than nanostructured materials) and Tl-free materials excellent for thermoelectric applications.

Visual Performance Manual.

ERIC Educational Resources Information Center

Chaikin, Rosalind B.; And Others

Intended for classroom teachers, the manual provides an approach to observation, assessment, record keeping, and remediation of students' visual performance. A list of clues for detecting visual performance difficulties and nine laws applicable to visual performance development tasks are given. Described in two sections are the materials, steps,…

Biotemplated materials for sustainable energy and environment: current status and challenges.

PubMed

Zhou, Han; Fan, Tongxiang; Zhang, Di

2011-10-17

Materials science will play a key role in the further development of emerging solutions for the increasing problems of energy and environment. Materials found in nature have many inspiring structures, such as hierarchical organizations, periodic architectures, or nanostructures, that endow them with amazing functions, such as energy harvesting and conversion, antireflection, structural coloration, superhydrophobicity, and biological self-assembly. Biotemplating is an effective strategy to obtain morphology-controllable materials with structural specificity, complexity, and related unique functions. Herein, we highlight the synthesis and application of biotemplated materials for six key areas of energy and environment technologies, namely, photocatalytic hydrogen evolution, CO(2) reduction, solar cells, lithium-ion batteries, photocatalytic degradation, and gas/vapor sensing. Although the applications differ from each other, a common fundamental challenge is to realize optimum structures for improved performances. We highlight the role of four typical structures derived from biological systems exploited to optimize properties: hierarchical (porous) structures, periodic (porous) structures, hollow structures, and nanostructures. We also provide examples of using biogenic elements (e.g., C, Si, N, I, P, S) for the creation of active materials. Finally, we disscuss the challenges of achieving the desired performance for large-scale commercial applications and provide some useful prototypes from nature for the biomimetic design of new materials or systems. The emphasis is mainly focused on the structural effects and compositional utilization of biotemplated materials. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Design and manufacturing considerations for high-performance gimbals used for land, sea, air, and space

NASA Astrophysics Data System (ADS)

Sweeney, Mike; Redd, Lafe; Vettese, Tom; Myatt, Ray; Uchida, David; Sellers, Del

2015-09-01

High performance stabilized EO/IR surveillance and targeting systems are in demand for a wide variety of military, law enforcement, and commercial assets for land, sea, air, and space. Operating ranges, wavelengths, and angular resolution capabilities define the requirements for EO/IR optics and sensors, and line of sight stabilization. Many materials and design configurations are available for EO/IR pointing gimbals depending on trade-offs of size, weight, power (SWaP), performance, and cost. Space and high performance military aircraft applications are often driven toward expensive but exceptionally performing beryllium and aluminum beryllium components. Commercial applications often rely on aluminum and composite materials. Gimbal design considerations include achieving minimized mass and inertia simultaneous with demanding structural, thermal, optical, and scene stabilization requirements when operating in dynamic operational environments. Manufacturing considerations include precision lapping and honing of ball bearing interfaces, brazing, welding, and casting of complex aluminum and beryllium alloy structures, and molding of composite structures. Several notional and previously developed EO/IR gimbal platforms are profiled that exemplify applicable design and manufacturing technologies.

Energy Conversion and Storage Program

NASA Astrophysics Data System (ADS)

Cairns, E. J.

1993-06-01

This report is the 1992 annual progress report for the Energy Conversion and Storage Program, a part of the Energy and Environment Division of the Lawrence Berkeley Laboratory. Work described falls into three broad areas: electrochemistry; chemical applications; and materials applications. The Energy Conversion and Storage Program applies principles of chemistry and materials science to solve problems in several areas: (1) production of new synthetic fuels, (2) development of high-performance rechargeable batteries and fuel cells, (3) development of advanced thermochemical processes for energy conversion, (4) characterization of complex chemical processes and chemical species, and (5) study and application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, novel materials, and advanced methods of analysis. Electrochemistry research aims to develop advanced power systems for electric vehicle and stationary energy storage applications. Chemical applications research includes topics such as separations, catalysis, fuels, and chemical analyses. Included in this program area are projects to develop improved, energy-efficient methods for processing product and waste streams from synfuel plants, coal gasifiers, and biomass conversion processes. Materials applications research includes evaluation of the properties of advanced materials, as well as development of novel preparation techniques. For example, techniques such as sputtering, laser ablation, and poised laser deposition are being used to produce high-temperature superconducting films.

Numerical modeling of materials processing applications of a pulsed cold cathode electron gun

NASA Astrophysics Data System (ADS)

Etcheverry, J. I.; Martínez, O. E.; Mingolo, N.

1998-04-01

A numerical study of the application of a pulsed cold cathode electron gun to materials processing is performed. A simple semiempirical model of the discharge is used, together with backscattering and energy deposition profiles obtained by a Monte Carlo technique, in order to evaluate the energy source term inside the material. The numerical computation of the heat equation with the calculated source term is performed in order to obtain useful information on melting and vaporization thresholds, melted radius and depth, and on the dependence of these variables on processing parameters such as operating pressure, initial voltage of the discharge and cathode-sample distance. Numerical results for stainless steel are presented, which demonstrate the need for several modifications of the experimental design in order to achieve a better efficiency.

Electric Motors for Non-Cryogenic Hybrid Electric and Turboelectric Propulsion

NASA Technical Reports Server (NTRS)

Duffy, Kirsten P.

2015-01-01

NASA Glenn Research Center is investigating hybrid electric and turboelectric propulsion concepts for future aircraft to reduce fuel burn, emissions, and noise. Systems studies show that the weight and efficiency of the electric system components need to be improved for this concept to be feasible. However, advances in motor component materials such as soft magnetic materials, hard magnetic materials, conductors, thermal insulation, and structural materials are expected in the coming years, and should improve motor performance. This study investigates several motor types for a one megawatt application, and projects the motor performance benefits of new component materials that might be available in the coming decades.

The application of waste fly ash and construction-waste in cement filling material in goaf

NASA Astrophysics Data System (ADS)

Chen, W. X.; Xiao, F. K.; Guan, X. H.; Cheng, Y.; Shi, X. P.; Liu, S. M.; Wang, W. W.

2018-01-01

As the process of urbanization accelerated, resulting in a large number of abandoned fly ash and construction waste, which have occupied the farmland and polluted the environment. In this paper, a large number of construction waste and abandoned fly ash are mixed into the filling material in goaf, the best formula of the filling material which containing a large amount of abandoned fly ash and construction waste is obtained, and the performance of the filling material is analyzed. The experimental results show that the cost of filling material is very low while the performance is very good, which have a good prospect in goaf.

Electric Motor Considerations for Non-Cryogenic Hybrid Electric and Turboelectric Propulsion

NASA Technical Reports Server (NTRS)

Duffy, Kirsten P.

2015-01-01

NASA Glenn Research Center is investigating hybrid electric and turboelectric propulsion concepts for future aircraft to reduce fuel burn, emissions, and noise. Systems studies show that the weight and efficiency of the electric system components need to be improved for this concept to be feasible. However, advances in motor component materials such as soft magnetic materials, hard magnetic materials, conductors, thermal insulation, and structural materials are expected in the coming years, and should improve motor performance. This study investigates several motor types for a one megawatt application, and projects the motor performance benefits of new component materials that might be available in the coming decades.

Performance evaluation of DAAF as a booster material using the onionskin test

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

Morris, John S; Francois, Elizabeth G; Hooks, Daniel E

Initiation of insensitive high explosive (IHE) formulations requires the use of a booster explosive in the initiation train. Booster material selection is crucial, as the initiation must reliably function across some spectrum of physical parameters. The interest in Diaminoazoxyfurazan (DAAF) for this application stems from the fact that it possesses many traits of an IHE but is shock sensitive enough to serve as an explosive booster. A hemispherical wave breakout test, termed the onionskin test, is one of the methods used to evaluate the performance of a booster material. The wave breakout time-position history at the surface of a hemisphericalmore » IHE charge is recorded and the relative uniformity of the breakout can be quantitatively compared between booster materials. A series of onionskin tests were performed to investigate breakout and propagation diaminoazoxyfurazan (DAAF) at low temperatures to evaluate ignition and detonation spreading in comparison to other explosives commonly used in booster applications. Some wave perturbation was observed with the DAAF booster in the onionskin tests presented. The results of these tests will be presented and discussed.« less

The application of space program fire retardant technology to housing

NASA Technical Reports Server (NTRS)

Riccitiello, S. R.; Heising, K. W.

1973-01-01

A review of the NASA fire research and developed fire retardant materials is presented with the objective to analyze and evaluate the concepts and materials to determine the practical applicability to the housing industry. The report presents the NASA materials, their performance in a fire environment and areas where further evaluation is required. The review establishes where advancements in the state of the art have been achieved and points out reasons why these advancements can not be directly applied to the housing industry in the near future.

High Performance COPVs for In-Space Storage of High Pressure Cryogenic Fuels

NASA Technical Reports Server (NTRS)

Schneider, Judy; Dyess, Mark; Hastings, Chad; Wang, Jun

2008-01-01

Polymeric composite overwrapped pressure vessels (COPVs) provide an attractive material system to support developing commercial launch business and alternate fuel ventures. However to be able to design with these materials, the mechanical behavior of the materials must be understood with regards to processing, performance, damage tolerance, and environment. For the storage of cryogenic propellants, it is important to evaluate the materials performance and impact damage resistance at cryogenic temperatures in order to minimize weight and to ensure safety and reliability. As part of this study, material tests of candidate fiber and resin systems were used as the basis for the selection of the material combinations for evaluation in a COPV at cryogenic conditions. This comprehensive approach has also been expanded to address issues with impact damage tolerance and material degradation due to environmental factors. KEY WORDS: Cryogenic testing, evaluation and applications for pressure vessels, COPVs, tanks, or storage vessels.

Refractory Materials for Flame Deflector Protection System Corrosion Control: Refractory Ceramics Literature Survey

NASA Technical Reports Server (NTRS)

Calle, Luz Marina; Hintze, Paul E.; Parlier, Christopher R.; Curran, Jerome P.; Kolody, Mark; Perusich, Stephen; Whitten, Mary C.; Trejo, David; Zidek, Jason; Sampson, Jeffrey W.;

In silico design of porous polymer networks: high-throughput screening for methane storage materials.

PubMed

Martin, Richard L; Simon, Cory M; Smit, Berend; Haranczyk, Maciej

2014-04-02

Porous polymer networks (PPNs) are a class of advanced porous materials that combine the advantages of cheap and stable polymers with the high surface areas and tunable chemistry of metal-organic frameworks. They are of particular interest for gas separation or storage applications, for instance, as methane adsorbents for a vehicular natural gas tank or other portable applications. PPNs are self-assembled from distinct building units; here, we utilize commercially available chemical fragments and two experimentally known synthetic routes to design in silico a large database of synthetically realistic PPN materials. All structures from our database of 18,000 materials have been relaxed with semiempirical electronic structure methods and characterized with Grand-canonical Monte Carlo simulations for methane uptake and deliverable (working) capacity. A number of novel structure-property relationships that govern methane storage performance were identified. The relationships are translated into experimental guidelines to realize the ideal PPN structure. We found that cooperative methane-methane attractions were present in all of the best-performing materials, highlighting the importance of guest interaction in the design of optimal materials for methane storage.

Materials and fabrication of electrode scaffolds for deposition of MnO2 and their true performance in supercapacitors

NASA Astrophysics Data System (ADS)

Cao, Jianyun; Li, Xiaohong; Wang, Yaming; Walsh, Frank C.; Ouyang, Jia-Hu; Jia, Dechang; Zhou, Yu

2015-10-01

MnO2 is a promising electrode material for high energy supercapacitors because of its large pseudo-capacitance. However, MnO2 suffers from low electronic conductivity and poor cation diffusivity, which results in poor utilization and limited rate performance of traditional MnO2 powder electrodes, obtained by pressing a mixed paste of MnO2 powder, conductive additive and polymer binder onto metallic current collectors. Developing binder-free MnO2 electrodes by loading nanoscale MnO2 deposits on pre-fabricated device-ready electrode scaffolds is an effective way to achieve both high power and energy performance. These electrode scaffolds, with interconnected skeletons and pore structures, will not only provide mechanical support and electron collection as traditional current collectors but also fast ion transfer tunnels, leading to high MnO2 utilization and rate performance. This review covers design strategies, materials and fabrication methods for the electrode scaffolds. Rational evaluation of the true performance of these electrodes is carried out, which clarifies that some of the electrodes with as-claimed exceptional performances lack potential in practical applications due to poor mass loading of MnO2 and large dead volume of inert scaffold materials/void spaces in the electrode structure. Possible ways to meet this challenge and bring MnO2 electrodes from laboratory studies to real-world applications are considered.

Advanced Ceramic Materials for Sharp Hot Structures: Material Development and On-Ground Arc-Jet Qualification Testing on Scaled Demonstrators

NASA Astrophysics Data System (ADS)

Scatteia, L.; Tomassetti, G.; Rufolo, G.; De Filippis, F.; Marino, G.

2005-02-01

This paper describes the work performed by the Italian Aerospace Research Centre (C.I.R.A. S.c.P.A.) in a technology project focused on the applicability of modified diboride compounds structures to the manufacturing of high performance and slender shaped hot structures for reusable launch vehicles. A prototypal multi-material structure, which couple reinforced diborides to a C/SiC frame, has been built with the aim to demonstrate the applicability of an innovative concept of nose cap to the fabrication of real parts to be installed ant subsequently tested on the flying test bed currently under development at CIRA. Particular relevance is given to the on-ground qualification test of the nose-cap scaled demonstrator which is underway at CIRA Arc-Jet facility SCIROCCO. Considering the specific typology of materials investigated, up to date, a consistent tests campaign at laboratory level has been performed and concluded in order to create a complete materials data base. The measured materials properties have been then used as input for the design phase that also used as inputs the aero-thermal loads associated with a reference re-entry mission. Our major preliminary findings indicate that the structure is thermally fully compliant with the environment requirements and shows local mechanical criticalities in specific areas such as the materials interfaces and hot/cold joining parts.

Aesthetic coatings for concrete bridge components

NASA Astrophysics Data System (ADS)

Kriha, Brent R.

This thesis evaluated the durability and aesthetic performance of coating systems for utilization in concrete bridge applications. The principle objectives of this thesis were: 1) Identify aesthetic coating systems appropriate for concrete bridge applications; 2) Evaluate the performance of the selected systems through a laboratory testing regimen; 3) Develop guidelines for coating selection, surface preparation, and application. A series of site visits to various bridges throughout the State of Wisconsin provided insight into the performance of common coating systems and allowed problematic structural details to be identified. To aid in the selection of appropriate coating systems, questionnaires were distributed to coating manufacturers, bridge contractors, and various DOT offices to identify high performing coating systems and best practices for surface preparation and application. These efforts supplemented a literature review investigating recent publications related to formulation, selection, surface preparation, application, and performance evaluation of coating materials.

Advantages and Challenges of Relaxor-PbTiO3 Ferroelectric Crystals for Electroacoustic Transducers- A Review.

PubMed

Zhang, Shujun; Li, Fei; Jiang, Xiaoning; Kim, Jinwook; Luo, Jun; Geng, Xuecang

2015-03-01

Relaxor-PbTiO 3 (PT) based ferroelectric crystals with the perovskite structure have been investigated over the last few decades due to their ultrahigh piezoelectric coefficients ( d 33 > 1500 pC/N) and electromechanical coupling factors ( k 33 > 90%), far outperforming state-of-the-art ferroelectric polycrystalline Pb(Zr,Ti)O 3 ceramics, and are at the forefront of advanced electroacoustic applications. In this review, the performance merits of relaxor-PT crystals in various electroacoustic devices are presented from a piezoelectric material viewpoint. Opportunities come from not only the ultrahigh properties, specifically coupling and piezoelectric coefficients, but through novel vibration modes and crystallographic/domain engineering. Figure of merits (FOMs) of crystals with various compositions and phases were established for various applications, including medical ultrasonic transducers, underwater transducers, acoustic sensors and tweezers. For each device application, recent developments in relaxor-PT ferroelectric crystals were surveyed and compared with state-of-the-art polycrystalline piezoelectrics, with an emphasis on their strong anisotropic features and crystallographic uniqueness, including engineered domain - property relationships. This review starts with an introduction on electroacoustic transducers and the history of piezoelectric materials. The development of the high performance relaxor-PT single crystals, with a focus on their uniqueness in transducer applications, is then discussed. In the third part, various FOMs of piezoelectric materials for a wide range of ultrasound applications, including diagnostic ultrasound, therapeutic ultrasound, underwater acoustic and passive sensors, tactile sensors and acoustic tweezers, are evaluated to provide a thorough understanding of the materials' behavior under operational conditions. Structure-property-performance relationships are then established. Finally, the impacts and challenges of relaxor-PT crystals are summarized to guide on-going and future research in the development of relaxor-PT crystals for the next generation electroacoustic transducers.

Structural Optimisation Of Payload Fairings

NASA Astrophysics Data System (ADS)

Santschi, Y.; Eaton, N.; Verheyden, S.; Michaud, V.

2012-07-01

RUAG Space are developing materials and processing technologies for manufacture of the Next Generation Launcher (NGL) payload fairing, together with the Laboratory of Polymer and Composite Technology at the EPFL, in a project running under the ESA Future Launchers Preparatory Program (FLPP). In this paper the general aims and scope of the project are described, details of the results obtained shall be presented at a later stage. RUAG Space design, develop and manufacture fairings for the European launch vehicles Ariane 5 and VEGA using well proven composite materials and production methods which provide adequate cost/performance ratio for these applications. However, the NGL shall make full use of innovations in materials and process technologies to achieve a gain in performance at a much reduced overall manufacturing cost. NGL is scheduled to become operational in 2025, with actual development beginning in 2014. In this current project the basic technology is being developed and validated, in readiness for application in the NGL. For this new application, an entirely new approach to the fairing manufacture is evaluated.

Materials and structures for stretchable energy storage and conversion devices.

PubMed

Xie, Keyu; Wei, Bingqing

2014-06-11

Stretchable energy storage and conversion devices (ESCDs) are attracting intensive attention due to their promising and potential applications in realistic consumer products, ranging from portable electronics, bio-integrated devices, space satellites, and electric vehicles to buildings with arbitrarily shaped surfaces. Material synthesis and structural design are core in the development of highly stretchable supercapacitors, batteries, and solar cells for practical applications. This review provides a brief summary of research development on the stretchable ESCDs in the past decade, from structural design strategies to novel materials synthesis. The focuses are on the fundamental insights of mechanical characteristics of materials and structures on the performance of the stretchable ESCDs, as well as challenges for their practical applications. Finally, some of the important directions in the areas of material synthesis and structural design facing the stretchable ESCDs are discussed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Recent progress of high performance polymer OLED and OPV materials for organic printed electronics.

PubMed

Sekine, Chizu; Tsubata, Yoshiaki; Yamada, Takeshi; Kitano, Makoto; Doi, Shuji

2014-06-01

The development of organic printed electronics has been expanding to a variety of applications and is expected to bring innovations to our future life. Along with this trend, high performance organic materials with cost-efficient fabrication processes and specific features such as thin, light weight, bendable, and low power consumption are required. A variety of organic materials have been investigated in the development of this field. The basic guidelines for material design and the recent progress of polymer-based organic light-emitting diodes (OLEDs) and organic photovoltaic cells (OPVs) are reported.

Recent progress of high performance polymer OLED and OPV materials for organic printed electronics

PubMed Central

Sekine, Chizu; Tsubata, Yoshiaki; Yamada, Takeshi; Kitano, Makoto; Doi, Shuji

2014-01-01

The development of organic printed electronics has been expanding to a variety of applications and is expected to bring innovations to our future life. Along with this trend, high performance organic materials with cost-efficient fabrication processes and specific features such as thin, light weight, bendable, and low power consumption are required. A variety of organic materials have been investigated in the development of this field. The basic guidelines for material design and the recent progress of polymer-based organic light-emitting diodes (OLEDs) and organic photovoltaic cells (OPVs) are reported. PMID:27877671

Recent progress of high performance polymer OLED and OPV materials for organic printed electronics

NASA Astrophysics Data System (ADS)

Sekine, Chizu; Tsubata, Yoshiaki; Yamada, Takeshi; Kitano, Makoto; Doi, Shuji

2014-06-01

The development of organic printed electronics has been expanding to a variety of applications and is expected to bring innovations to our future life. Along with this trend, high performance organic materials with cost-efficient fabrication processes and specific features such as thin, light weight, bendable, and low power consumption are required. A variety of organic materials have been investigated in the development of this field. The basic guidelines for material design and the recent progress of polymer-based organic light-emitting diodes (OLEDs) and organic photovoltaic cells (OPVs) are reported.

Application study of filamentary composites in a commercial jet aircraft fuselage

NASA Technical Reports Server (NTRS)

Johnson, R. W.; June, R. R.

1972-01-01

A study of applications of filamentary composite materials to aircraft fuselage structure was performed. General design criteria were established and material studies conducted using the 727-200 forebody as the primary structural component. Three design approaches to the use of composites were investigated: uniaxial reinforcement of metal structure, uniaxial and biaxial reinforcement of metal structure, and an all-composite design. Materials application studies for all three concepts were conducted on fuselage shell panels, keel beam, floor beams, floor panels, body frames, fail-safe straps, and window frames. Cost benefit studies were conducted and developmental program costs estimated. On the basis of weight savings, cost effectiveness, developmental program costs, and potential for early application on commercial aircraft, the unaxial design is recommended for a 5-year flight service evaluation program.

High Absorptance Coatings for THz Applications

NASA Technical Reports Server (NTRS)

Wollack, Edward J.

2012-01-01

High absorptance materials find application throughout the electromagnetic spectrum as radiation terminations, calibration standards, and glint reduction coatings. Successful use of materials at millimeter through submillimeter wavelengths requires an accurate knowledge and control over their thermal, mechanical, and electromagnetic properties in order to achieve the desired response while minimizing mass and volume. In practice, the achieved blackness is intimately linked to the material properties and geometry. Here, we summarize the characteristics of a variety of tunable artificial dielectric mixtures appropriate for THz applications at room and cryogenic temperatures. Theoretical guidelines for their application will be provided in the context of the effective-medium mean-field-approximation. The performance of these coatings as elements of reflectance standards, radiometric flux calibrators, passive thermal radiators, and stray light suppression baffles for imaging systems will be reviewed.

Feasibility analysis of ultra high performance concrete for prestressed concrete bridge applications.

DOT National Transportation Integrated Search

2010-07-01

UHPC is an emerging material technology in which concrete develops very high : compressive strengths and exhibits improved tensile strength and toughness. A : comprehensive literature and historical application review was completed to determine the :...

5 CFR 890.203 - Application for approval of, and proposal of amendments to, health benefit plans.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 20415. Application letters must be accompanied by any descriptive material, financial data, or other... operating experience to enable OPM to realistically evaluate the plan's past and expected future performance...

5 CFR 890.203 - Application for approval of, and proposal of amendments to, health benefit plans.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 20415. Application letters must be accompanied by any descriptive material, financial data, or other... operating experience to enable OPM to realistically evaluate the plan's past and expected future performance...

5 CFR 890.203 - Application for approval of, and proposal of amendments to, health benefit plans.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 20415. Application letters must be accompanied by any descriptive material, financial data, or other... operating experience to enable OPM to realistically evaluate the plan's past and expected future performance...

5 CFR 890.203 - Application for approval of, and proposal of amendments to, health benefit plans.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 20415. Application letters must be accompanied by any descriptive material, financial data, or other... operating experience to enable OPM to realistically evaluate the plan's past and expected future performance...

5 CFR 890.203 - Application for approval of, and proposal of amendments to, health benefit plans.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 20415. Application letters must be accompanied by any descriptive material, financial data, or other... operating experience to enable OPM to realistically evaluate the plan's past and expected future performance...

Early-state damage detection, characterization, and evolution using high-resolution computed tomography

NASA Astrophysics Data System (ADS)

Grandin, Robert John

Safely using materials in high performance applications requires adequately understanding the mechanisms which control the nucleation and evolution of damage. Most of a material's operational life is spent in a state with noncritical damage, and, for example in metals only a small portion of its life falls within the classical Paris Law regime of crack growth. Developing proper structural health and prognosis models requires understanding the behavior of damage in these early stages within the material's life, and this early-stage damage occurs on length scales at which the material may be considered "granular'' in the sense that the discrete regions which comprise the whole are large enough to require special consideration. Material performance depends upon the characteristics of the granules themselves as well as the interfaces between granules. As a result, properly studying early-stage damage in complex, granular materials requires a means to characterize changes in the granules and interfaces. The granular-scale can range from tenths of microns in ceramics, to single microns in fiber-reinforced composites, to tens of millimeters in concrete. The difficulty of direct-study is often overcome by exhaustive testing of macro-scale damage caused by gross material loads and abuse. Such testing, for example optical or electron microscopy, destructive and further, is costly when used to study the evolution of damage within a material and often limits the study to a few snapshots. New developments in high-resolution computed tomography (HRCT) provide the necessary spatial resolution to directly image the granule length-scale of many materials. Successful application of HRCT with fiber-reinforced composites, however, requires extending the HRCT performance beyond current limits. This dissertation will discuss improvements made in the field of CT reconstruction which enable resolutions to be pushed to the point of being able to image the fiber-scale damage structures and the application of this new capability to the study of early-stage damage.

Recent Advances in the Fabrication and Application of Screen-Printed Electrochemical (Bio)Sensors Based on Carbon Materials for Biomedical, Agri-Food and Environmental Analyses

PubMed Central

Hughes, Gareth; Westmacott, Kelly; Honeychurch, Kevin C.; Crew, Adrian; Pemberton, Roy M.; Hart, John P.

2016-01-01

This review describes recent advances in the fabrication of electrochemical (bio)sensors based on screen-printing technology involving carbon materials and their application in biomedical, agri-food and environmental analyses. It will focus on the various strategies employed in the fabrication of screen-printed (bio)sensors, together with their performance characteristics; the application of these devices for the measurement of selected naturally occurring biomolecules, environmental pollutants and toxins will be discussed. PMID:27690118

Producing Hybrid Metal Composites by Combining Additive Manufacturing and Casting

DOE PAGES

Pawlowski, Alex E.; Splitter, Derek A.; Muth, Thomas R.; ...

2017-10-01

Additive manufacturing by itself provides many benefits, but by combining different materials processing techniques like traditional casting with additive manufacturing to create hybrid processes, custom materials can be tailor-made and mass produced for applications with specific performance needs.

10 CFR 74.4 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... sequential performances of a material control test which is designed to detect anomalies potentially... capability required by § 74.53. Material control test means a comparison of a pre-established alarm threshold... into practical application for experimental and demonstration purposes, including the experimental...

10 CFR 74.4 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... sequential performances of a material control test which is designed to detect anomalies potentially... capability required by § 74.53. Material control test means a comparison of a pre-established alarm threshold... into practical application for experimental and demonstration purposes, including the experimental...

10 CFR 74.4 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... sequential performances of a material control test which is designed to detect anomalies potentially... capability required by § 74.53. Material control test means a comparison of a pre-established alarm threshold... into practical application for experimental and demonstration purposes, including the experimental...

10 CFR 74.4 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... sequential performances of a material control test which is designed to detect anomalies potentially... capability required by § 74.53. Material control test means a comparison of a pre-established alarm threshold... into practical application for experimental and demonstration purposes, including the experimental...

10 CFR 74.4 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... sequential performances of a material control test which is designed to detect anomalies potentially... capability required by § 74.53. Material control test means a comparison of a pre-established alarm threshold... into practical application for experimental and demonstration purposes, including the experimental...

Achieving High Performance Perovskite Solar Cells

NASA Astrophysics Data System (ADS)

Yang, Yang

2015-03-01

Recently, metal halide perovskite based solar cell with the characteristics of rather low raw materials cost, great potential for simple process and scalable production, and extreme high power conversion efficiency (PCE), have been highlighted as one of the most competitive technologies for next generation thin film photovoltaic (PV). In UCLA, we have realized an efficient pathway to achieve high performance pervoskite solar cells, where the findings are beneficial to this unique materials/devices system. Our recent progress lies in perovskite film formation, defect passivation, transport materials design, interface engineering with respect to high performance solar cell, as well as the exploration of its applications beyond photovoltaics. These achievements include: 1) development of vapor assisted solution process (VASP) and moisture assisted solution process, which produces perovskite film with improved conformity, high crystallinity, reduced recombination rate, and the resulting high performance; 2) examination of the defects property of perovskite materials, and demonstration of a self-induced passivation approach to reduce carrier recombination; 3) interface engineering based on design of the carrier transport materials and the electrodes, in combination with high quality perovskite film, which delivers 15 ~ 20% PCEs; 4) a novel integration of bulk heterojunction to perovskite solar cell to achieve better light harvest; 5) fabrication of inverted solar cell device with high efficiency and flexibility and 6) exploration the application of perovskite materials to photodetector. Further development in film, device architecture, and interfaces will lead to continuous improved perovskite solar cells and other organic-inorganic hybrid optoelectronics.

Modeling Materials: Design for Planetary Entry, Electric Aircraft, and Beyond

NASA Technical Reports Server (NTRS)

Thompson, Alexander; Lawson, John W.

2014-01-01

NASA missions push the limits of what is possible. The development of high-performance materials must keep pace with the agency's demanding, cutting-edge applications. Researchers at NASA's Ames Research Center are performing multiscale computational modeling to accelerate development times and further the design of next-generation aerospace materials. Multiscale modeling combines several computationally intensive techniques ranging from the atomic level to the macroscale, passing output from one level as input to the next level. These methods are applicable to a wide variety of materials systems. For example: (a) Ultra-high-temperature ceramics for hypersonic aircraft-we utilized the full range of multiscale modeling to characterize thermal protection materials for faster, safer air- and spacecraft, (b) Planetary entry heat shields for space vehicles-we computed thermal and mechanical properties of ablative composites by combining several methods, from atomistic simulations to macroscale computations, (c) Advanced batteries for electric aircraft-we performed large-scale molecular dynamics simulations of advanced electrolytes for ultra-high-energy capacity batteries to enable long-distance electric aircraft service; and (d) Shape-memory alloys for high-efficiency aircraft-we used high-fidelity electronic structure calculations to determine phase diagrams in shape-memory transformations. Advances in high-performance computing have been critical to the development of multiscale materials modeling. We used nearly one million processor hours on NASA's Pleiades supercomputer to characterize electrolytes with a fidelity that would be otherwise impossible. For this and other projects, Pleiades enables us to push the physics and accuracy of our calculations to new levels.

Terbium Ion Doping in Ca3Co4O9: A Step towards High-Performance Thermoelectric Materials

PubMed Central

Saini, Shrikant; Yaddanapudi, Haritha Sree; Tian, Kun; Yin, Yinong; Magginetti, David; Tiwari, Ashutosh

2017-01-01

The potential of thermoelectric materials to generate electricity from the waste heat can play a key role in achieving a global sustainable energy future. In order to proceed in this direction, it is essential to have thermoelectric materials that are environmentally friendly and exhibit high figure of merit, ZT. Oxide thermoelectric materials are considered ideal for such applications. High thermoelectric performance has been reported in single crystals of Ca3Co4O9. However, for large scale applications single crystals are not suitable and it is essential to develop high-performance polycrystalline thermoelectric materials. In polycrystalline form, Ca3Co4O9 is known to exhibit much weaker thermoelectric response than in single crystal form. Here, we report the observation of enhanced thermoelectric response in polycrystalline Ca3Co4O9 on doping Tb ions in the material. Polycrystalline Ca3−xTbxCo4O9 (x = 0.0–0.7) samples were prepared by a solid-state reaction technique. Samples were thoroughly characterized using several state of the art techniques including XRD, TEM, SEM and XPS. Temperature dependent Seebeck coefficient, electrical resistivity and thermal conductivity measurements were performed. A record ZT of 0.74 at 800 K was observed for Tb doped Ca3Co4O9 which is the highest value observed till date in any polycrystalline sample of this system. PMID:28317853

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.

Developments in the Material Fabrication and Performance of LiMn2O4 dCld Cathode Material

DTIC Science & Technology

2016-06-13

Lithium manganese spinel; Lithium rechargeable batteries , Lithium - ion battery ...requirements. Lithium and lithium - ion battery systems are highly sought after for rechargeable applications due to their high energy density (Wh/L...further optimization, the robust LixMn2O4-dCld spinel materials will be promising active materials for future integration into lithium - ion batteries

Template-free synthesis of renewable macroporous carbon via yeast cells for high-performance supercapacitor electrode materials.

PubMed

Sun, Hongmei; He, Wenhui; Zong, Chenghua; Lu, Lehui

2013-03-01

The urgent need for sustainable development has forced material scientists to explore novel materials for next-generation energy storage devices through a green and facile strategy. In this context, yeast, which is a large group of single cell fungi widely distributed in nature environments, will be an ideal candidate for developing effective electrode materials with fascinating structures for high-performance supercapacitors. With this in mind, herein, we present the first example of creating three-dimensional (3D) interpenetrating macroporous carbon materials via a template-free method, using the green, renewable, and widespread yeast cells as the precursors. Remarkably, when the as-prepared materials are used as the electrode materials for supercapacitors, they exhibit outstanding performance with high specific capacitance of 330 F g(-1) at a current density of 1 A g(-1), and good stability, even after 1000 charge/discharge cycles. The approach developed in this work provides a new view of making full use of sustainable resources endowed by nature, opening the avenue to designing and producing robust materials with great promising applications in high-performance energy-storage devices.

CF60 Concrete Composition Design and Application on Fudiankou Xijiang Super Large Bridge

NASA Astrophysics Data System (ADS)

Qiu, Yi Mei; Wen, Sen Yuan; Chen, Jun Xiang

2018-06-01

Guangxi Wuzhou City Ring Road Fudiankou Xijiang super large bridge CF60 concrete is a new multi-phase composite high-performance concrete, this paper for the Fudiankou Xijiang bridge structure and characteristics of the project, in accordance with the principle of local materials and technical specification requirements, combined with the site conditions of CF60 engineering high performance concrete component materials, proportion and the technical performance, quantify the main physical and mechanical performance index. Analysis main influencing factors of the technical indicators, reasonable adjustment of concrete mix design parameters, and the use of technical means of admixture and multi-function composite admixture of concrete, obtain the optimal proportion of good work, process, mechanical properties stability and durability of engineering properties, recommend and verification of concrete mix; to explore the CF60 high performance concrete Soil in the Fudiankou Xijiang bridge application technology, detection and tracking the quality of concrete construction, concrete structure during the construction of the key technology and control points is proposed, evaluation of CF60 high performance concrete in the actual engineering application effect and benefit to ensure engineering quality of bridge structure and service life, and super long span bridge engineering construction to provide basis and reference.

Synthesis, properties and applications of 2D non-graphene materials.

PubMed

Wang, Feng; Wang, Zhenxing; Wang, Qisheng; Wang, Fengmei; Yin, Lei; Xu, Kai; Huang, Yun; He, Jun

2015-07-24

As an emerging class of new materials, two-dimensional (2D) non-graphene materials, including layered and non-layered, and their heterostructures are currently attracting increasing interest due to their promising applications in electronics, optoelectronics and clean energy. In contrast to traditional semiconductors, such as Si, Ge and III-V group materials, 2D materials show significant merits of ultrathin thickness, very high surface-to-volume ratio, and high compatibility with flexible devices. Owing to these unique properties, while scaling down to ultrathin thickness, devices based on these materials as well as artificially synthetic heterostructures exhibit novel and surprising functions and performances. In this review, we aim to provide a summary on the state-of-the-art research activities on 2D non-graphene materials. The scope of the review will cover the preparation of layered and non-layered 2D materials, construction of 2D vertical van der Waals and lateral ultrathin heterostructures, and especially focus on the applications in electronics, optoelectronics and clean energy. Moreover, the review is concluded with some perspectives on the future developments in this field.

Reversible creation of nanostructures between identical or different species of materials

NASA Astrophysics Data System (ADS)

Jang, Hyun-Ik; Ko, Sungho; Park, Junyong; Lee, Dong-Eon; Jeon, Seokwoo; Ahn, Chi Won; Yoo, Kwang Soo; Park, Jae Hong

2012-07-01

In this study, accurate nanostructures with various aspect ratios are created on several types of material. This work is highly applicable to the energy, optical, and nano-bio fields, for example. A silicon (Si) nano-mold is preserved using the method described, and target nanostructures are replicated reversibly and unlimitedly to or from various hard and soft materials. It is also verified that various materials can be applied to the substrates. The results confirm that the target nanostructures are successfully created in precise straight line structures and circle structures with various aspect ratios, including extremely high aspect ratios of 1:18. It is suggested that the optimal replicating and demolding process of nanostructures with high aspect ratios, which are the most problematic, could be controlled by means of the surface energy between the functional materials. Relevant numerical and analytical studies are also performed. It is possible to expand the applicability of the nanostructured mold by adopting various backing materials, including rounded substrates. The scope of the applications is extended further by transferring the nanostructures between different species of materials including metallic materials as well as identical species.

Progress in development of coated indexable cemented carbide inserts for machining of iron based work piece materials

NASA Astrophysics Data System (ADS)

Czettl, C.; Pohler, M.

2016-03-01

Increasing demands on material properties of iron based work piece materials, e.g. for the turbine industry, complicate the machining process and reduce the lifetime of the cutting tools. Therefore, improved tool solutions, adapted to the requirements of the desired application have to be developed. Especially, the interplay of macro- and micro geometry, substrate material, coating and post treatment processes is crucial for the durability of modern high performance tool solutions. Improved and novel analytical methods allow a detailed understanding of material properties responsible for the wear behaviour of the tools. Those support the knowledge based development of tailored cutting materials for selected applications. One important factor for such a solution is the proper choice of coating material, which can be synthesized by physical or chemical vapor deposition techniques. Within this work an overview of state-of-the-art coated carbide grades is presented and application examples are shown to demonstrate their high efficiency. Machining processes for a material range from cast iron, low carbon steels to high alloyed steels are covered.

TiO2/porous adsorbents: Recent advances and novel applications.

PubMed

MiarAlipour, Shayan; Friedmann, Donia; Scott, Jason; Amal, Rose

2018-01-05

This article reviews two interrelated areas of research: the first is the use of TiO 2 -supported adsorbent materials as enhanced heterogeneous photocatalysts and their application to various reactions for organic pollutant removal from air and water; the second is the combination of adsorbent materials with TiO 2 photocatalysts which aims to efficiently regenerate adsorbent materials using illumination. By reviewing both areas of research, the following topics are covered; (i) photocatalytic activation of TiO 2; (ii) related properties of photocatalytic TiO 2; (iii) shortcomings of photocatalytic processes; (iv) preparation methods of composite TiO 2 /adsorbent materials and their photocatalytic performance; (v) properties of common adsorbents and their applications for pollutant removal from air and water; (vi) adsorbent regeneration methods and their economic and operational issues; (vii) conclusions and future outlooks. This topic has not been previously reviewed to such an extent, and considerable knowledge can be gained from assembling the large number of studies on adsorption-photocatalysis combinations. As such, this review provides guidance for researchers working in the fields of environmental and chemical engineering focussing on organic pollutant removal and the engineering of new high performance photocatalytic TiO 2 -supported porous adsorbent materials. Copyright © 2017 Elsevier B.V. All rights reserved.

Exploiting the Dynamics of Soft Materials for Machine Learning

PubMed Central

Hauser, Helmut; Li, Tao; Pfeifer, Rolf

2018-01-01

Abstract Soft materials are increasingly utilized for various purposes in many engineering applications. These materials have been shown to perform a number of functions that were previously difficult to implement using rigid materials. Here, we argue that the diverse dynamics generated by actuating soft materials can be effectively used for machine learning purposes. This is demonstrated using a soft silicone arm through a technique of multiplexing, which enables the rich transient dynamics of the soft materials to be fully exploited as a computational resource. The computational performance of the soft silicone arm is examined through two standard benchmark tasks. Results show that the soft arm compares well to or even outperforms conventional machine learning techniques under multiple conditions. We then demonstrate that this system can be used for the sensory time series prediction problem for the soft arm itself, which suggests its immediate applicability to a real-world machine learning problem. Our approach, on the one hand, represents a radical departure from traditional computational methods, whereas on the other hand, it fits nicely into a more general perspective of computation by way of exploiting the properties of physical materials in the real world. PMID:29708857

Exploiting the Dynamics of Soft Materials for Machine Learning.

PubMed

Nakajima, Kohei; Hauser, Helmut; Li, Tao; Pfeifer, Rolf

2018-06-01

Soft materials are increasingly utilized for various purposes in many engineering applications. These materials have been shown to perform a number of functions that were previously difficult to implement using rigid materials. Here, we argue that the diverse dynamics generated by actuating soft materials can be effectively used for machine learning purposes. This is demonstrated using a soft silicone arm through a technique of multiplexing, which enables the rich transient dynamics of the soft materials to be fully exploited as a computational resource. The computational performance of the soft silicone arm is examined through two standard benchmark tasks. Results show that the soft arm compares well to or even outperforms conventional machine learning techniques under multiple conditions. We then demonstrate that this system can be used for the sensory time series prediction problem for the soft arm itself, which suggests its immediate applicability to a real-world machine learning problem. Our approach, on the one hand, represents a radical departure from traditional computational methods, whereas on the other hand, it fits nicely into a more general perspective of computation by way of exploiting the properties of physical materials in the real world.

Challenges and Opportunities in Reactive Processing and Applications of Advanced Ceramic Materials

NASA Technical Reports Server (NTRS)

Singh, Mrityunjay

2003-01-01

Recently, there has been a great deal of interest in the research, development, and commercialization of innovative synthesis and processing technologies for advanced ceramics and composite materials. Reactive processing approaches have been actively considered due to their robustness, flexibility, and affordability. A wide variety of silicon carbide-based advanced ceramics and composites are currently being fabricated using the processing approaches involving reactive infiltration of liquid and gaseous species into engineered fibrous or microporous carbon performs. The microporous carbon performs have been fabricated using the temperature induced phase separation and pyrolysis of two phase organic (resin-pore former) mixtures and fiber reinforcement of carbon and ceramic particulate bodies. In addition, pyrolyzed native plant cellulose tissues also provide unique carbon templates for manufacturing of non-oxide and oxide ceramics. In spite of great interest in this technology due to their affordability and robustness, there is a lack of scientific basis for process understanding and many technical challenges still remain. The influence of perform properties and other parameters on the resulting microstructure and properties of final material is not well understood. In this presentation, mechanism of silicon-carbon reaction in various systems and the effect of perform microstructure on the mechanical properties of advanced silicon carbide based materials will be discussed. Various examples of applications of reactively processed advanced silicon carbide ceramics and composite materials will be presented.

Novel and high-performance asymmetric micro-supercapacitors based on graphene quantum dots and polyaniline nanofibers

NASA Astrophysics Data System (ADS)

Liu, Wenwen; Yan, Xingbin; Chen, Jiangtao; Feng, Yaqiang; Xue, Qunji

2013-06-01

In comparison with graphene sheets, graphene quantum dots (GQDs) exhibit novel chemical/physical properties including nanometer-size, abundant edge defects, good electrical conductivity, high mobility, chemical inertia, stable photoluminescence and better surface grafting, making them promising for fabricating various novel devices. In the present work, an asymmetric micro-supercapacitor, using GQDs as negative active material and polyaniline (PANI) nanofibers as positive active material, is built for the first time by a simple and controllable two-step electro-deposition on interdigital finger gold electrodes. Electrochemical measurements reveal that the as-made GQDs//PANI asymmetric micro-supercapacitor has a more excellent rate capability (up to 1000 V s-1) than previously reported electrode materials, as well as faster power response capability (with a very short relaxation time constant of 115.9 μs) and better cycling stability after 1500 cycles in aqueous electrolyte. On this basis, an all-solid-state GQDs//PANI asymmetric micro-supercapacitor is fabricated using H3PO4-polyvinyl alcohol gel as electrolyte, which also exhibits desirable electrochemical capacitive performances. These encouraging results presented here may open up new insight into GQDs with highly promising applications in high-performance energy-storage devices, and further expand the potential applications of GQDs beyond the energy-oriented application of GQDs discussed above.In comparison with graphene sheets, graphene quantum dots (GQDs) exhibit novel chemical/physical properties including nanometer-size, abundant edge defects, good electrical conductivity, high mobility, chemical inertia, stable photoluminescence and better surface grafting, making them promising for fabricating various novel devices. In the present work, an asymmetric micro-supercapacitor, using GQDs as negative active material and polyaniline (PANI) nanofibers as positive active material, is built for the first time by a simple and controllable two-step electro-deposition on interdigital finger gold electrodes. Electrochemical measurements reveal that the as-made GQDs//PANI asymmetric micro-supercapacitor has a more excellent rate capability (up to 1000 V s-1) than previously reported electrode materials, as well as faster power response capability (with a very short relaxation time constant of 115.9 μs) and better cycling stability after 1500 cycles in aqueous electrolyte. On this basis, an all-solid-state GQDs//PANI asymmetric micro-supercapacitor is fabricated using H3PO4-polyvinyl alcohol gel as electrolyte, which also exhibits desirable electrochemical capacitive performances. These encouraging results presented here may open up new insight into GQDs with highly promising applications in high-performance energy-storage devices, and further expand the potential applications of GQDs beyond the energy-oriented application of GQDs discussed above. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr01139a

Feasibility studies on explosive detection and homeland security applications using a neutron and x-ray combined computed tomography system

NASA Astrophysics Data System (ADS)

Sinha, V.; Srivastava, A.; Lee, H. K.; Liu, X.

2013-05-01

The successful creation and operation of a neutron and X-ray combined computed tomography (NXCT) system has been demonstrated by researchers at the Missouri University of Science and Technology. The NXCT system has numerous applications in the field of material characterization and object identification in materials with a mixture of atomic numbers represented. Presently, the feasibility studies have been performed for explosive detection and homeland security applications, particularly in concealed material detection and determination of the light atomic number materials. These materials cannot be detected using traditional X-ray imaging. The new system has the capability to provide complete structural and compositional information due to the complementary nature of X-ray and neutron interactions with materials. The design of the NXCT system facilitates simultaneous and instantaneous imaging operation, promising enhanced detection capabilities of explosive materials, low atomic number materials and illicit materials for homeland security applications. In addition, a sample positioning system allowing the user to remotely and automatically manipulate the sample makes the system viable for commercial applications. Several explosives and weapon simulants have been imaged and the results are provided. The fusion algorithms which combine the data from the neutron and X-ray imaging produce superior images. This paper is a compete overview of the NXCT system for feasibility studies of explosive detection and homeland security applications. The design of the system, operation, algorithm development, and detection schemes are provided. This is the first combined neutron and X-ray computed tomography system in operation. Furthermore, the method of fusing neutron and X-ray images together is a new approach which provides high contrast images of the desired object. The system could serve as a standardized tool in nondestructive testing of many applications, especially in explosives detection and homeland security research.

Thermal Performance Of Space Suit Elements With Aerogel Insulation For Moon And Mars Exploration

NASA Technical Reports Server (NTRS)

Tang, Henry H.; Orndoff, Evelyne S.; Trevino, Luis A.

2006-01-01

Flexible fiber-reinforced aerogel composites were studied for use as insulation materials of a future space suit for Moon and Mars exploration. High flexibility and good thermal insulation properties of fiber-reinforced silica aerogel composites at both high and low vacuum conditions make it a promising insulation candidate for the space suit application. This paper first presents the results of a durability (mechanical cycling) study of these aerogels composites in the context of retaining their thermal performance. The study shows that some of these Aerogels materials retained most of their insulation performance after up to 250,000 cycles of mechanical flex cycling. This paper also examines the problem of integrating these flexible aerogel composites into the current space suit elements. Thermal conductivity evaluations are proposed for different types of aerogels space suit elements to identify the lay-up concept that may have the best overall thermal performance for both Moon and Mars environments. Potential solutions in mitigating the silica dusting issue related to the application of these aerogels materials for the space suit elements are also discussed.

Low-dimensional carbon and MXene-based electrochemical capacitor electrodes.

PubMed

Yoon, Yeoheung; Lee, Keunsik; Lee, Hyoyoung

2016-04-29

Due to their unique structure and outstanding intrinsic physical properties such as extraordinarily high electrical conductivity, large surface area, and various chemical functionalities, low-dimension-based materials exhibit great potential for application in electrochemical capacitors (ECs). The electrical properties of electrochemical capacitors are determined by the electrode materials. Because energy charge storage is a surface process, the surface properties of the electrode materials greatly influence the electrochemical performance of the cell. Recently, graphene, a single layer of sp(2)-bonded carbon atoms arrayed into two-dimensional carbon nanomaterial, has attracted wide interest as an electrode material for electrochemical capacitor applications due to its unique properties, including a high electrical conductivity and large surface area. Several low-dimensional materials with large surface areas and high conductivity such as onion-like carbons (OLCs), carbide-derived carbons (CDCs), carbon nanotubes (CNTs), graphene, metal hydroxide, transition metal dichalcogenides (TMDs), and most recently MXene, have been developed for electrochemical capacitors. Therefore, it is useful to understand the current issues of low-dimensional materials and their device applications.

Synaptic electronics: materials, devices and applications.

PubMed

Kuzum, Duygu; Yu, Shimeng; Wong, H-S Philip

2013-09-27

In this paper, the recent progress of synaptic electronics is reviewed. The basics of biological synaptic plasticity and learning are described. The material properties and electrical switching characteristics of a variety of synaptic devices are discussed, with a focus on the use of synaptic devices for neuromorphic or brain-inspired computing. Performance metrics desirable for large-scale implementations of synaptic devices are illustrated. A review of recent work on targeted computing applications with synaptic devices is presented.

An investigation into the relationship between thermal shock resistance and ballistic performance of ceramic materials

NASA Astrophysics Data System (ADS)

Beaumont, Robert

Currently, there are no reliable methods for screening potential armour materials and hence full-scale ballistic trials are needed. These are both costly and time-consuming in terms of the actual test and also in the materials development that needs to take place to produce sufficient material to give a meaningful result. Whilst it will not be possible to dispense with ballistic trials before material deployment in armour applications, the ability to shorten the development cycle would be advantageous. The thermal shock performance of ceramic armour materials has been highlighted as potential marker for ballistic performance. Hence the purpose of this study was to investigate this further. A new thermal shock technique that reproduced features relevant to ballistic testing was sought. As it would be beneficial to have a simple test that did not use much material, a water-drop method was adopted. This was combined with a variety of characterisation techniques, administered pre- and post-shock. The methods included measurement of the amplitude of ultrasonic wave transmission through the sample alongside residual strength testing using a biaxial ball-on-ball configuration and reflected light and confocal microscopy. Once the protocols had been refined the testing regime was applied to a group of ceramic materials. The materials selected were from two broad groups: alumina and carbide materials. Carbide ceramics show superior performance to alumina ceramics in ballistic applications so it was essential that any screening test would be easily able to differentiate the two groups. Within the alumina family, two commercially available materials, AD995 and Sintox FA, were selected. These were tested alongside three developmental silicon carbide-boron carbide composites, which had identical chemical compositions but different microstructures and thus presented more of a challenge in terms of differentiation. The results from the various tests were used to make predictions about the relative ballistic performances. The tests showed that all of the composites would outperform the alumina materials. Further, all of the tests led to the prediction that AD995 would be better ballistically than Sintox FA, possibly up to a factor of two better. The predictions were in very good agreement with literature values for depth-of-penetration testing. The situation was more complex for the carbide materials, with different tests leading to slightly different predictions. However, the predictions from the ultrasonic tests were consistent with the available ballistic data. Indeed, the ultrasonic data proved to be the most consistent predictor of ballistic performance, supporting the view that the total defect population is more relevant than a ‘critical flaw’ concept. Thus, it can be concluded that with further development, and subject to validation across a wider spread of materials and microstructures, thermal shock testing coupled with ultrasonic measurements could form the basis of a future screening test for ceramics for armour applications.

Development of the Spacecraft Materials Selector Expert System

NASA Technical Reports Server (NTRS)

Pippin, H. G.

2000-01-01

A specific knowledge base to evaluate the on-orbit performance of selected materials on spacecraft is being developed under contract to the NASA SEE program. An artificial intelligence software package, the Boeing Expert System Tool (BEST), contains an inference engine used to operate knowledge bases constructed to selectively recall and distribute information about materials performance in space applications. This same system is used to make estimates of the environmental exposures expected for a given space flight. The performance capabilities of the Spacecraft Materials Selector (SMS) knowledge base are described in this paper. A case history for a planned flight experiment on ISS is shown as an example of the use of the SMS, and capabilities and limitations of the knowledge base are discussed.

Needs assessment for nondestructive testing and materials characterization for improved reliability in structural ceramics for heat engines

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

Johnson, D.R.; McClung, R.W.; Janney, M.A.

1987-08-01

A needs assessment was performed for nondestructive testing and materials characterization to achieve improved reliability in ceramic materials for heat engine applications. Raw materials, green state bodies, and sintered ceramics were considered. The overall approach taken to improve reliability of structural ceramics requires key inspections throughout the fabrication flowsheet, including raw materials, greed state, and dense parts. The applications of nondestructive inspection and characterization techniques to ceramic powders and other raw materials, green ceramics, and sintered ceramics are discussed. The current state of inspection technology is reviewed for all identified attributes and stages of a generalized flowsheet for advanced structuralmore » ceramics, and research and development requirements are identified and listed in priority order. 164 refs., 3 figs.« less

Structural materials issues for the next generation fission reactors

NASA Astrophysics Data System (ADS)

Chant, I.; Murty, K. L.

2010-09-01

Generation-IV reactor design concepts envisioned thus far cater to a common goal of providing safer, longer lasting, proliferation-resistant, and economically viable nuclear power plants. The foremost consideration in the successful development and deployment of Gen-W reactor systems is the performance and reliability issues involving structural materials for both in-core and out-of-core applications. The structural materials need to endure much higher temperatures, higher neutron doses, and extremely corrosive environments, which are beyond the experience of the current nuclear power plants. Materials under active consideration for use in different reactor components include various ferritic/martensitic steels, austenitic stainless steels, nickel-base superalloys, ceramics, composites, etc. This article addresses the material requirements for these advanced fission reactor types, specifically addressing structural materials issues depending on the specific application areas.

Design and Application of Hybrid Magnetic Field-Eddy Current Probe

NASA Technical Reports Server (NTRS)

Wincheski, Buzz; Wallace, Terryl; Newman, Andy; Leser, Paul; Simpson, John

2013-01-01

The incorporation of magnetic field sensors into eddy current probes can result in novel probe designs with unique performance characteristics. One such example is a recently developed electromagnetic probe consisting of a two-channel magnetoresistive sensor with an embedded single-strand eddy current inducer. Magnetic flux leakage maps of ferrous materials are generated from the DC sensor response while high-resolution eddy current imaging is simultaneously performed at frequencies up to 5 megahertz. In this work the design and optimization of this probe will be presented, along with an application toward analysis of sensory materials with embedded ferromagnetic shape-memory alloy (FSMA) particles. The sensory material is designed to produce a paramagnetic to ferromagnetic transition in the FSMA particles under strain. Mapping of the stray magnetic field and eddy current response of the sample with the hybrid probe can thereby image locations in the structure which have experienced an overstrain condition. Numerical modeling of the probe response is performed with good agreement with experimental results.

High Performance Oxides-Based Thermoelectric Materials

NASA Astrophysics Data System (ADS)

Ren, Guangkun; Lan, Jinle; Zeng, Chengcheng; Liu, Yaochun; Zhan, Bin; Butt, Sajid; Lin, Yuan-Hua; Nan, Ce-Wen

2015-01-01

Thermoelectric materials have attracted much attention due to their applications in waste-heat recovery, power generation, and solid state cooling. In comparison with thermoelectric alloys, oxide semiconductors, which are thermally and chemically stable in air at high temperature, are regarded as the candidates for high-temperature thermoelectric applications. However, their figure-of-merit ZT value has remained low, around 0.1-0.4 for more than 20 years. The poor performance in oxides is ascribed to the low electrical conductivity and high thermal conductivity. Since the electrical transport properties in these thermoelectric oxides are strongly correlated, it is difficult to improve both the thermoelectric power and electrical conductivity simultaneously by conventional methods. This review summarizes recent progresses on high-performance oxide-based thermoelectric bulk-materials including n-type ZnO, SrTiO3, and In2O3, and p-type Ca3Co4O9, BiCuSeO, and NiO, enhanced by heavy-element doping, band engineering and nanostructuring.

LDEF Materials Results for Spacecraft Applications

NASA Technical Reports Server (NTRS)

Whitaker, Ann F. (Compiler); Gregory, John (Compiler)

1993-01-01

These proceedings describe the application of LDEF data to spacecraft and payload design, and emphasize where space environmental effects on materials research and development is needed as defined by LDEF data. The LDEF six years of exposure of materials has proven to be by far the most comprehensive source of information ever obtained on the long-term performance of materials in the space environment. The conference provided a forum for materials scientists and engineers to review and critically assess the LDEF results from the standpoint of their relevance, significance, and impact on spacecraft design practice. The impact of the LDEF findings on materials selection and qualification, and the needs and plans for further study, were addressed from several perspectives. Many timely and needed changes and modifications in external spacecraft materials selection have occurred as a result of LDEF investigations.

Evaluation of Eco-Efficiency and Performance of Retrofit Materials

NASA Astrophysics Data System (ADS)

Gopinath, Smitha; Rama Chandra Murthy, A.; Iyer, Nagesh R.; Kokila, S.

2015-12-01

In this work three materials namely Fiber Reinforced Polymer (FRP), ferrocement and Textile Reinforced Concrete (TRC) have been evaluated towards their performance efficiency and eco-effectiveness for sustainable retrofitting applications. Investigations have been carried out for flexural strengthening of RC beams with FRP, ferrocement and TRC. It is observed that in the case of FRP, it is not possible to tailor the material according to design requirements and most of the time strengthened structure becomes over stiff. Eco-effectiveness of these retrofitting materials has been evaluated by computing the embodied energy. It is observed that the amount of CO2 emitted by TRC is less compared to other retrofit materials. Further, the performance point of retrofitted RC frames has been evaluated and damage index has been calculated to find out the effective retrofit material. It is concluded that, if RC frame is retrofitted with FRP and TRC, it undergoes less damage compared to ferrocement.

Predicting Material Performance in the Space Environment from Laboratory Test Data, Static Design Environments, and Space Weather Models

NASA Technical Reports Server (NTRS)

Minow, Josep I.; Edwards, David L.

2008-01-01

Qualifying materials for use in the space environment is typically accomplished with laboratory exposures to simulated UV/EUV, atomic oxygen, and charged particle radiation environments with in-situ or subsequent measurements of material properties of interest to the particular application. Choice of environment exposure levels are derived from static design environments intended to represent either mean or extreme conditions that are anticipated to be encountered during a mission. The real space environment however is quite variable. Predictions of the on orbit performance of a material qualified to laboratory environments can be done using information on 'space weather' variations in the real environment. This presentation will first review the variability of space environments of concern for material degradation and then demonstrate techniques for using test data to predict material performance in a variety of space environments from low Earth orbit to interplanetary space using historical measurements and space weather models.

Designing high-performance layered thermoelectric materials through orbital engineering

PubMed Central

Zhang, Jiawei; Song, Lirong; Madsen, Georg K. H.; Fischer, Karl F. F.; Zhang, Wenqing; Shi, Xun; Iversen, Bo B.

2016-01-01

Thermoelectric technology, which possesses potential application in recycling industrial waste heat as energy, calls for novel high-performance materials. The systematic exploration of novel thermoelectric materials with excellent electronic transport properties is severely hindered by limited insight into the underlying bonding orbitals of atomic structures. Here we propose a simple yet successful strategy to discover and design high-performance layered thermoelectric materials through minimizing the crystal field splitting energy of orbitals to realize high orbital degeneracy. The approach naturally leads to design maps for optimizing the thermoelectric power factor through forming solid solutions and biaxial strain. Using this approach, we predict a series of potential thermoelectric candidates from layered CaAl2Si2-type Zintl compounds. Several of them contain nontoxic, low-cost and earth-abundant elements. Moreover, the approach can be extended to several other non-cubic materials, thereby substantially accelerating the screening and design of new thermoelectric materials. PMID:26948043

Evaluation of Some Finishing Properties of Oil Palm Particleboard for Furniture Application

NASA Astrophysics Data System (ADS)

Ratnasingam, J.; Nyugen, V.; Ioras, F.

The finishing properties of particleboard made from the Empty-Fruit Bunch (EFB) of oil palm (Elaeis guineensis Jacq.) were evaluated for its suitability for furniture applications, using different coating and overlay materials. The results found that the thick plastic-formica overlay provided the best surface finish, in terms of surface smoothness, adhesion strength and impact resistance. Although the polyurethane lacquer provided an acceptable finish, its quality and performance is not comparable to that of the thick plastic overlay. Despite the fact that the use of such overlay material may render the material not aesthetically appealing and limit it to concealed applications or where the thick overlay material is tolerated, its cost competitiveness and environmental friendliness may be able to position the oil palm particleboard as a substitute for the conventional wood-based particleboard in the furniture manufacturing industry.

Failure Analysis of Multilayered Suspension Plasma-Sprayed Thermal Barrier Coatings for Gas Turbine Applications

NASA Astrophysics Data System (ADS)

Gupta, M.; Markocsan, N.; Rocchio-Heller, R.; Liu, J.; Li, X.-H.; Östergren, L.

2018-02-01

Improvement in the performance of thermal barrier coatings (TBCs) is one of the key objectives for further development of gas turbine applications. The material most commonly used as TBC topcoat is yttria-stabilized zirconia (YSZ). However, the usage of YSZ is limited by the operating temperature range which in turn restricts the engine efficiency. Materials such as pyrochlores, perovskites, rare earth garnets are suitable candidates which could replace YSZ as they exhibit lower thermal conductivity and higher phase stability at elevated temperatures. The objective of this work was to investigate different multilayered TBCs consisting of advanced topcoat materials fabricated by suspension plasma spraying (SPS). The investigated topcoat materials were YSZ, dysprosia-stabilized zirconia, gadolinium zirconate, and ceria-yttria-stabilized zirconia. All topcoats were deposited by TriplexPro-210TM plasma spray gun and radial injection of suspension. Lifetime of these samples was examined by thermal cyclic fatigue and thermal shock testing. Microstructure analysis of as-sprayed and failed specimens was performed with scanning electron microscope. The failure mechanisms in each case have been discussed in this article. The results show that SPS could be a promising route to produce multilayered TBCs for high-temperature applications.

Metal-organic frameworks in chromatography.

PubMed

Yusuf, Kareem; Aqel, Ahmad; ALOthman, Zeid

2014-06-27

Metal-organic frameworks (MOFs) emerged approximately two decades ago and are the youngest class of porous materials. Despite their short existence, MOFs are finding applications in a variety of fields because of their outstanding chemical and physical properties. This review article focuses on the applications of MOFs in chromatography, including high-performance liquid chromatography (HPLC), gas chromatography (GC), and other chromatographic techniques. The use of MOFs in chromatography has already had a significant impact; however, the utilisation of MOFs in chromatography is still less common than other applications, and the number of MOF materials explored in chromatography applications is limited. Copyright © 2014 Elsevier B.V. All rights reserved.

Materials Control for Aerospace Applications

NASA Technical Reports Server (NTRS)

Ferguson, Michael

2005-01-01

The distant future of mankind and the ultimate survivability of the human race, as it is known today, will depend on mans' ability to break earthly bonds and establish new territorial positions throughout the universe. Man must therefore be positioned to not only travel to, but also, to readily adapt to numerous and varying environments. For this mass migration across the galaxies nothing is as import to the human race as is NASA's future missions into Low Earth Orbit (LEO), to the moon, and/or Mars. These missions will form the building blocks to eternity for mankind. From these missions, NASA will develop the foundations for these building blocks based on sound engineering and scientific principles, both known and yet to be discovered. The integrity of the program will lead to development, tracking and control of the most basic elements of hardware production: That being development and control of applications of space flight materials. Choosing the right material for design purposes involves many considerations, such as governmental regulations associated with manufacturing operations, both safety of usage and of manufacturing, general material usage requirements, material longevity and performance requirements, material interfacing compatibility and material usage environments. Material performance is subject to environmental considerations in as much as a given material may perform exceptionally well at standard temperatures and pressures while performing poorly under non-standard conditions. These concerns may be found true for materials relative to the extreme temperatures and vacuum gradients of high altitude usage. The only way to assure that flight worthy materials are used in design is through testing. However, as with all testing, it requires both time on schedule and cost to the operation. One alternative to this high cost testing approach is to rely on a materials control system established by NASA. The NASA community relies on the MAPTIS materials control system founded at MSFC and supported by the other NASA Centers. This system is a data bank of all materials used in space flight operations. These materials are rated for several characteristics that are common concerns in high altitude or deep space usage: Odor, off gassing, material fluid compatibility, toxicity, corrosion susceptibility, stress corrosion susceptibility, etc.

Engineered Graphene Materials: Synthesis and Applications for Polymer Electrolyte Membrane Fuel Cells.

PubMed

He, Daping; Tang, Haolin; Kou, Zongkui; Pan, Mu; Sun, Xueliang; Zhang, Jiujun; Mu, Shichun

2017-05-01

Engineered graphene materials (EGMs) with unique structures and properties have been incorporated into various components of polymer electrolyte membrane fuel cells (PEMFCs) such as electrode, membrane, and bipolar plates to achieve enhanced performances in terms of electrical conductivity, mechanical durability, corrosion resistance, and electrochemical surface area. This research news article provides an overview of the recent development in EGMs and EGM-based PEMFCs with a focus on the effects of EGMs on PEMFC performance when they are incorporated into different components of PEMFCs. The challenges of EGMs for practical PEMFC applications in terms of production scale, stability, conductivity, and coupling capability with other materials are also discussed and the corresponding measures and future research trends to overcome such challenges are proposed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Process research on non-CZ silicon material

NASA Technical Reports Server (NTRS)

1982-01-01

High risk, high payoff research areas associated with he process for producing photovoltaic modules using non-CZ sheet material are investigated. All investigations are being performed using dendritic web silicon, but all processes are directly applicable to other ribbon forms of sheet material. The technical feasibility of forming front and back junctions in non-CZ silicon using liquid dopant techniques was determined. Numerous commercially available liquid phosphorus and boron dopant solutions are investigated. Temperature-time profiles to achieve N(+) and P(+) sheet resistivities of 60 + or - 10 and 40 + or - s10 ohms per square centimeter respectively are established. A study of the optimal method of liquid dopant application is performed. The technical feasibility of forming a liquid applied diffusion mask to replace the more costly chemical vapor deposited SiO2 diffusion mask was also determined.

Optimization of material/device parameters of CdTe photovoltaic for solar cells applications

NASA Astrophysics Data System (ADS)

Wijewarnasuriya, Priyalal S.

2016-05-01

Cadmium telluride (CdTe) has been recognized as a promising photovoltaic material for thin-film solar cell applications due to its near optimum bandgap of ~1.5 eV and high absorption coefficient. The energy gap is near optimum for a single-junction solar cell. The high absorption coefficient allows films as thin as 2.5 μm to absorb more than 98% of the above-bandgap radiation. Cells with efficiencies near 20% have been produced with poly-CdTe materials. This paper examines n/p heterostructure device architecture. The performance limitations related to doping concentrations, minority carrier lifetimes, absorber layer thickness, and surface recombination velocities at the back and front interfaces is assessed. Ultimately, the paper explores device architectures of poly- CdTe and crystalline CdTe to achieve performance comparable to gallium arsenide (GaAs).

Ultra-broad polypyrrole (PPy) nano-ribbons seeded by racemic surfactants aggregates and their high-performance electromagnetic radiation elimination.

PubMed

Jiao, Yingzhi; Wu, Fan; Zhang, Kun; Sun, Mengxiao; Xie, Aming; Dong, Wei

2017-08-04

Ribbon-like nano-structures possess high aspect ratios, and thus have great potential in the development of high-performance microwave absorption (MA) materials that can effectively eliminate adverse electromagnetic radiation. However, these nano-structures have been scarcely constructed in the field of MA, because of the lack of efficient synthetic routes. Herein, we developed an efficient method to successfully construct polypyrrole (PPy) nano-ribbons using the self-assembly aggregates of a racemic surfactant as the seeds. The frequency range with a reflection loss value of lower than -10 dB reached 7.68 GHz in the frequency range of 10.32-18.00 GHz, and surpassed all the currently reported PPy nano-structures, as well as most other MA nano-materials. Through changing the amount of surfactant, both the nano-structures and MA performance can be effectively regulated. Furthermore, the reason behind the high-performance MA of PPy nano-ribbons has been deeply explored. It opens up the opportunity for the application of conducting polymer nano-ribbons as a lightweight and tunable high-performance MA material, especially in applications of special aircraft and flexible electronics.

Ultra-broad polypyrrole (PPy) nano-ribbons seeded by racemic surfactants aggregates and their high-performance electromagnetic radiation elimination

NASA Astrophysics Data System (ADS)

Jiao, Yingzhi; Wu, Fan; Zhang, Kun; Sun, Mengxiao; Xie, Aming; Dong, Wei

2017-08-01

Ribbon-like nano-structures possess high aspect ratios, and thus have great potential in the development of high-performance microwave absorption (MA) materials that can effectively eliminate adverse electromagnetic radiation. However, these nano-structures have been scarcely constructed in the field of MA, because of the lack of efficient synthetic routes. Herein, we developed an efficient method to successfully construct polypyrrole (PPy) nano-ribbons using the self-assembly aggregates of a racemic surfactant as the seeds. The frequency range with a reflection loss value of lower than -10 dB reached 7.68 GHz in the frequency range of 10.32-18.00 GHz, and surpassed all the currently reported PPy nano-structures, as well as most other MA nano-materials. Through changing the amount of surfactant, both the nano-structures and MA performance can be effectively regulated. Furthermore, the reason behind the high-performance MA of PPy nano-ribbons has been deeply explored. It opens up the opportunity for the application of conducting polymer nano-ribbons as a lightweight and tunable high-performance MA material, especially in applications of special aircraft and flexible electronics.

Thermomechanical Fatigue Durability of T650-35/PMR-15 Sheet-Molding Compound Evaluated

NASA Technical Reports Server (NTRS)

Castelli, Michael G.

1999-01-01

High-performance polymer matrix composites (PMC's) continue to be the focus of a number of research efforts aimed at developing cost-effective, lightweight material alternatives for advanced aerospace and aeropropulsion applications. These materials not only offer significant advantages in specific stiffness and strength over their current metal counterparts, but they can be designed and manufactured to eliminate joints and fasteners by combining individual components into integral subassemblies, thus making them extremely attractive for commercial applications. With much emphasis on the low-cost manufacturing aspects of advanced composite structures, there is heightened interest in high-performance sheet-molding compounds (SMC's). Researchers at the NASA Lewis Research Center, in cooperation with the Allison Advanced Development Company, completed an investigation examining the use of T650-35/PMR-15 SMC for a midstage inner-vane endwall application within a gas turbine engine compressor. This component resides in the engine flow path and is subjected not only to high airflow rates, but also to elevated temperatures and pressures. This application is unique in that it represents a very aggressive use of high-performance SMC's, raising obvious concerns related to durability and property retention in the presence of microstructural damage. Therefore, it was necessary to evaluate the fatigue behavior and damage tolerance of this material subjected to a representative thermomechanical fatigue (TMF) mission-cycle loading spectrum.

MnO2 prepared by hydrothermal method and electrochemical performance as anode for lithium-ion battery.

PubMed

Feng, Lili; Xuan, Zhewen; Zhao, Hongbo; Bai, Yang; Guo, Junming; Su, Chang-Wei; Chen, Xiaokai

2014-01-01

Two α-MnO2 crystals with caddice-clew-like and urchin-like morphologies are prepared by the hydrothermal method, and their structure and electrochemical performance are characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), galvanostatic cell cycling, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS). The morphology of the MnO2 prepared under acidic condition is urchin-like, while the one prepared under neutral condition is caddice-clew-like. The identical crystalline phase of MnO2 crystals is essential to evaluate the relationship between electrochemical performances and morphologies for lithium-ion battery application. In this study, urchin-like α-MnO2 crystals with compact structure have better electrochemical performance due to the higher specific capacity and lower impedance. We find that the relationship between electrochemical performance and morphology is different when MnO2 material used as electrochemical supercapacitor or as anode of lithium-ion battery. For lithium-ion battery application, urchin-like MnO2 material has better electrochemical performance.

One-dimensional photonic crystal optical limiter.

PubMed

Soon, Boon Yi; Haus, Joseph; Scalora, Michael; Sibilia, Concita

2003-08-25

We explore a new passive optical limiter design using transverse modulation instability in the one-dimensional photonic crystal (PC) using x(3) materials. The performance of PC optical limiters strongly depends on the choice of the materials and the geometry and it improves as the duration of the incident pulse is extended. PC optical limiter performance is compared with that of a device made from homogeneous material. We identify three criteria for benchmarking the PC optical limiter. We also include a discussion of the advantages and disadvantages of PC optical limiters for real world applications.

Water-Based Coating Simplifies Circuit Board Manufacturing

NASA Technical Reports Server (NTRS)

2008-01-01

The Structures and Materials Division at Glenn Research Center is devoted to developing advanced, high-temperature materials and processes for future aerospace propulsion and power generation systems. The Polymers Branch falls under this division, and it is involved in the development of high-performance materials, including polymers for high-temperature polymer matrix composites; nanocomposites for both high- and low-temperature applications; durable aerogels; purification and functionalization of carbon nanotubes and their use in composites; computational modeling of materials and biological systems and processes; and developing polymer-derived molecular sensors. Essentially, this branch creates high-performance materials to reduce the weight and boost performance of components for space missions and aircraft engine components. Under the leadership of chemical engineer, Dr. Michael Meador, the Polymers Branch boasts world-class laboratories, composite manufacturing facilities, testing stations, and some of the best scientists in the field.

Survey material choices in haematology EQA: a confounding factor in automated counting performance assessment.

PubMed

De la Salle, Barbara

2017-02-15

The complete blood count (CBC) is one of the most frequently requested tests in laboratory medicine, performed in a range of healthcare situations. The provision of an ideal assay material for external quality assessment is confounded by the fragility of the cellular components of blood, the lack of commutability of stabilised whole blood material and the lack of certified reference materials and methods to which CBC results can be traced. The choice of assay material between fresh blood, extended life assay material and fully stabilised, commercially prepared, whole blood material depends upon the scope and objectives of the EQA scheme. The introduction of new technologies in blood counting and the wider clinical application of parameters from the extended CBC will bring additional challenges for the EQA provider.

Graphene-based materials: fabrication and application for adsorption in analytical chemistry.

PubMed

Wang, Xin; Liu, Bo; Lu, Qipeng; Qu, Qishu

2014-10-03

Graphene, a single layer of carbon atoms densely packed into a honeycomb crystal lattice with unique electronic, chemical, and mechanical properties, is the 2D allotrope of carbon. Owing to the remarkable properties, graphene and graphene-based materials are likely to find potential applications as a sorbent in analytical chemistry. The current review focuses predominantly on the recent development of graphene-based materials and demonstrates their enhanced performance in adsorption of organic compounds, metal ions, and solid phase extraction as well as in separation science since mostly 2012. Copyright © 2014 Elsevier B.V. All rights reserved.

Electrochemistry of metal chloride cathodes in sodium batteries

NASA Technical Reports Server (NTRS)

Ratnakumar, B. V.; Di Stefano, S.; Halpert, G.

1990-01-01

Fundamental electrochemical studies on three candidate materials, i.e., FeCl2, NiCl2, and CuCl2, were carried out using various techniques, such as cyclic voltammetry, linear polarization, potentiodynamic polarization, and ac impedance. These studies were aimed at identifying various rate processes in the reduction, elucidating the reaction mechanisms, and determining the kinetic parameters for the reduction. The limitations in the performance of these cathode materials in high power density applications were also examined. Finally, recommendations were made from these studies for the selection of a candidate system among these materials for future NASA applications.

Resin Transfer Moldable Polyimides Developed for High-Temperature Applications

NASA Technical Reports Server (NTRS)

Meador, Mary Ann

2000-01-01

High-temperature polyimides, such as PMR 15 (which was developed at the NASA Glenn Research Center at Lewis Field), are becoming an increasingly important class of materials for a variety of aerospace applications, such as aircraft engine components and propulsion and airframe components for reusable launch vehicles (RLV s). Because of their high specific strength and low density, use of these materials in place of more traditional aerospace materials, such as titanium, can significantly reduce component and vehicle weight, leading to reductions in fuel consumption (and pollutants), increases in payload and passenger capacity, and improvements in vehicle performance.

Polymeric metallic electrodes for rechargeable battery applications

NASA Technical Reports Server (NTRS)

Somoano, R.

1982-01-01

A review is presented on the status of plastic metal electrodes, emphasizing the use of polyacetylene as a prototype polymeric material. The electrochemical characteristics of polyacetylene are examined; and the potential use of this material, as well as other types of plastic metal electrodes, in batteries is evaluated. Several problem areas which must be solved before polyacetylene can be widely used in battery applications are discussed, including the problem of electrolyte stability, the problem that the depth of discharge and the energy density is limited by the metal-semiconductor transition, and also the poor electrochemical performance of impure material.

Mesoporous Prussian blue analogues: template-free synthesis and sodium-ion battery applications.

PubMed

Yue, Yanfeng; Binder, Andrew J; Guo, Bingkun; Zhang, Zhiyong; Qiao, Zhen-An; Tian, Chengcheng; Dai, Sheng

2014-03-17

The synthesis of mesoporous Prussian blue analogues through a template-free methodology and the application of these mesoporous materials as high-performance cathode materials in sodium-ion batteries is presented. Crystalline mesostructures were produced through a synergistically coupled nanocrystal formation and aggregation mechanism. As cathodes for sodium-ion batteries, the Prussian blue analogues all show a reversible capacity of 65 mA h g-1 at low current rate and show excellent cycle stability. The reported method stands as an environmentally friendly and low-cost alternative to hard or soft templating for the fabrication of mesoporous materials.

Review of electronic transport models for thermoelectric materials

NASA Astrophysics Data System (ADS)

Bulusu, A.; Walker, D. G.

2008-07-01

Thermoelectric devices have gained importance in recent years as viable solutions for applications such as spot cooling of electronic components, remote power generation in space stations and satellites etc. These solid-state devices have long been known for their reliability rather than their efficiency; they contain no moving parts, and their performance relies primarily on material selection, which has not generated many excellent candidates. Research in recent years has been focused on developing both thermoelectric structures and materials that have high efficiency. In general, thermoelectric research is two-pronged with (1) experiments focused on finding new materials and structures with enhanced thermoelectric performance and (2) analytical models that predict thermoelectric behavior to enable better design and optimization of materials and structures. While numerous reviews have discussed the importance of and dependence on materials for thermoelectric performance, an overview of how to predict the performance of various materials and structures based on fundamental quantities is lacking. In this paper we present a review of the theoretical models that were developed since thermoelectricity was first observed in 1821 by Seebeck and how these models have guided experimental material search for improved thermoelectric devices. A new quantum model is also presented, which provides opportunities for the optimization of nanoscale materials to enhance thermoelectric performance.

Information Management Workflow and Tools Enabling Multiscale Modeling Within ICME Paradigm

NASA Technical Reports Server (NTRS)

Arnold, Steven M.; Bednarcyk, Brett A.; Austin, Nic; Terentjev, Igor; Cebon, Dave; Marsden, Will

2016-01-01

With the increased emphasis on reducing the cost and time to market of new materials, the need for analytical tools that enable the virtual design and optimization of materials throughout their processing - internal structure - property - performance envelope, along with the capturing and storing of the associated material and model information across its lifecycle, has become critical. This need is also fueled by the demands for higher efficiency in material testing; consistency, quality and traceability of data; product design; engineering analysis; as well as control of access to proprietary or sensitive information. Fortunately, material information management systems and physics-based multiscale modeling methods have kept pace with the growing user demands. Herein, recent efforts to establish workflow for and demonstrate a unique set of web application tools for linking NASA GRC's Integrated Computational Materials Engineering (ICME) Granta MI database schema and NASA GRC's Integrated multiscale Micromechanics Analysis Code (ImMAC) software toolset are presented. The goal is to enable seamless coupling between both test data and simulation data, which is captured and tracked automatically within Granta MI®, with full model pedigree information. These tools, and this type of linkage, are foundational to realizing the full potential of ICME, in which materials processing, microstructure, properties, and performance are coupled to enable application-driven design and optimization of materials and structures.

Two-Dimensional Materials for Halide Perovskite-Based Optoelectronic Devices.

PubMed

Chen, Shan; Shi, Gaoquan

2017-06-01

Halide perovskites have high light absorption coefficients, long charge carrier diffusion lengths, intense photoluminescence, and slow rates of non-radiative charge recombination. Thus, they are attractive photoactive materials for developing high-performance optoelectronic devices. These devices are also cheap and easy to be fabricated. To realize the optimal performances of halide perovskite-based optoelectronic devices (HPODs), perovskite photoactive layers should work effectively with other functional materials such as electrodes, interfacial layers and encapsulating films. Conventional two-dimensional (2D) materials are promising candidates for this purpose because of their unique structures and/or interesting optoelectronic properties. Here, we comprehensively summarize the recent advancements in the applications of conventional 2D materials for halide perovskite-based photodetectors, solar cells and light-emitting diodes. The examples of these 2D materials are graphene and its derivatives, mono- and few-layer transition metal dichalcogenides (TMDs), graphdiyne and metal nanosheets, etc. The research related to 2D nanostructured perovskites and 2D Ruddlesden-Popper perovskites as efficient and stable photoactive layers is also outlined. The syntheses, functions and working mechanisms of relevant 2D materials are introduced, and the challenges to achieving practical applications of HPODs using 2D materials are also discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Packing and deploying Soft Origami to and from cylindrical volumes with application to automotive airbags

PubMed Central

Nelson, Todd G.; Zimmerman, Trent K.; Fernelius, Janette D.; Magleby, Spencer P.; Howell, Larry L.

2016-01-01

Packing soft-sheet materials of approximately zero bending stiffness using Soft Origami (origami patterns applied to soft-sheet materials) into cylindrical volumes and their deployment via mechanisms or internal pressure (inflation) is of interest in fields including automobile airbags, deployable heart stents, inflatable space habitats, and dirigible and parachute packing. This paper explores twofold patterns, the ‘flasher’ and the ‘inverted-cone fold’, for packing soft-sheet materials into cylindrical volumes. Two initial packing methods and mechanisms are examined for each of the flasher and inverted-cone fold patterns. An application to driver’s side automobile airbags is performed, and deployment tests are completed to compare the influence of packing method and origami pattern on deployment performance. Following deployment tests, two additional packing methods for the inverted-cone fold pattern are explored and applied to automobile airbags. It is shown that modifying the packing method (using different methods to impose the same base pattern on the soft-sheet material) can lead to different deployment performance. In total, two origami patterns and six packing methods are examined, and the benefits of using Soft Origami patterns and packing methods are discussed. Soft Origami is presented as a viable method for efficiently packing soft-sheet materials into cylindrical volumes. PMID:27703707

Packing and deploying Soft Origami to and from cylindrical volumes with application to automotive airbags

NASA Astrophysics Data System (ADS)

Bruton, Jared T.; Nelson, Todd G.; Zimmerman, Trent K.; Fernelius, Janette D.; Magleby, Spencer P.; Howell, Larry L.

2016-09-01

Packing soft-sheet materials of approximately zero bending stiffness using Soft Origami (origami patterns applied to soft-sheet materials) into cylindrical volumes and their deployment via mechanisms or internal pressure (inflation) is of interest in fields including automobile airbags, deployable heart stents, inflatable space habitats, and dirigible and parachute packing. This paper explores twofold patterns, the `flasher' and the `inverted-cone fold', for packing soft-sheet materials into cylindrical volumes. Two initial packing methods and mechanisms are examined for each of the flasher and inverted-cone fold patterns. An application to driver's side automobile airbags is performed, and deployment tests are completed to compare the influence of packing method and origami pattern on deployment performance. Following deployment tests, two additional packing methods for the inverted-cone fold pattern are explored and applied to automobile airbags. It is shown that modifying the packing method (using different methods to impose the same base pattern on the soft-sheet material) can lead to different deployment performance. In total, two origami patterns and six packing methods are examined, and the benefits of using Soft Origami patterns and packing methods are discussed. Soft Origami is presented as a viable method for efficiently packing soft-sheet materials into cylindrical volumes.

Packing and deploying Soft Origami to and from cylindrical volumes with application to automotive airbags.

PubMed

Bruton, Jared T; Nelson, Todd G; Zimmerman, Trent K; Fernelius, Janette D; Magleby, Spencer P; Howell, Larry L

2016-09-01

Packing soft-sheet materials of approximately zero bending stiffness using Soft Origami (origami patterns applied to soft-sheet materials) into cylindrical volumes and their deployment via mechanisms or internal pressure (inflation) is of interest in fields including automobile airbags, deployable heart stents, inflatable space habitats, and dirigible and parachute packing. This paper explores twofold patterns, the 'flasher' and the 'inverted-cone fold', for packing soft-sheet materials into cylindrical volumes. Two initial packing methods and mechanisms are examined for each of the flasher and inverted-cone fold patterns. An application to driver's side automobile airbags is performed, and deployment tests are completed to compare the influence of packing method and origami pattern on deployment performance. Following deployment tests, two additional packing methods for the inverted-cone fold pattern are explored and applied to automobile airbags. It is shown that modifying the packing method (using different methods to impose the same base pattern on the soft-sheet material) can lead to different deployment performance. In total, two origami patterns and six packing methods are examined, and the benefits of using Soft Origami patterns and packing methods are discussed. Soft Origami is presented as a viable method for efficiently packing soft-sheet materials into cylindrical volumes.

Well-ordered mesoporous Fe2O3/C composites as high performance anode materials for sodium-ion batteries.

PubMed

Li, Mei; Ma, Chao; Zhu, Qian-Cheng; Xu, Shu-Mao; Wei, Xiao; Wu, Yong-Min; Tang, Wei-Ping; Wang, Kai-Xue; Chen, Jie-Sheng

2017-04-11

Sodium-ion batteries have attracted considerable attention in recent years. In order to promote the practical application of sodium-ion batteries, the electrochemical performances, such as specific capacity, reversibility, and rate capability of the anode materials, should be further improved. In this work, a Fe 2 O 3 /C composite with a well-ordered mesoporous structure is prepared via a facile co-impregnation method by using mesoporous silica SBA-15 as a hard template. When used as an anode material for sodium-ion batteries, the well-ordered mesoporous structure ensures fast mass transport kinetics. The presence of nano-sized Fe 2 O 3 particles confined within the carbon walls significantly enhances the specific capacity of the composite. The carbon walls in the composite act not only as an active material contributing to the specific capacity, but also as a conductive matrix improving the cycling stability of Fe 2 O 3 nanoparticles. As a result, the well-ordered mesoporous Fe 2 O 3 /C composite exhibits high specific capacity, excellent cycleability, and high rate capability. It is proposed that this simple co-impregnation method is applicable for the preparation of well-ordered mesoporous transition oxide/carbon composite electrode materials for high performance sodium-ion and lithium-ion batteries.

Market projections of cellulose nanomaterial-enabled products- Part 1: Applications

Treesearch

Jo Anne Shatkin; Theodore H. Wegner; E.M. (Ted) Bilek; John Cowie

2014-01-01

Nanocellulose provides a new materials platform for the sustainable production of high-performance nano-enabled products in an array of applications. In this paper, potential applications for cellulose nanomaterials are identified as the first step toward estimating market volume. The overall study, presented in two parts, estimates market volume on the basis of...

Achieving ICME with Multiscale Modeling: The Effects of Constituent Properties and Processing on the Performance of Laminated Polymer Matrix Composite Structures

NASA Technical Reports Server (NTRS)

Pineda, Evan Jorge; Bednarcyk, Brett A.; Arnold, Steven M.

2014-01-01

Integrated computational materials engineering (ICME) is a useful approach for tailoring the performance of a material. For fiber-reinforced composites, not only do the properties of the constituents of the composite affect the performance, but so does the architecture (or microstructure) of the constituents. The generalized method of cells is demonstrated to be a viable micromechanics tool for determining the effects of the microstructure on the performance of laminates. The micromechanics is used to predict the inputs for a macroscale model for a variety of different fiber volume fractions, and fiber architectures. Using this technique, the material performance can be tailored for specific applications by judicious selection of constituents, volume fraction, and architectural arrangement given a particular manufacturing scenario

Investigation on the Flexural Creep Stiffness Behavior of PC-ABS Material Processed by Fused Deposition Modeling Using Response Surface Definitive Screening Design

NASA Astrophysics Data System (ADS)

Mohamed, Omar Ahmed; Masood, Syed Hasan; Bhowmik, Jahar Lal

2017-03-01

The resistance of polymeric materials to time-dependent plastic deformation is an important requirement of the fused deposition modeling (FDM) design process, its processed products, and their application for long-term loading, durability, and reliability. The creep performance of the material and part processed by FDM is the fundamental criterion for many applications with strict dimensional stability requirements, including medical implants, electrical and electronic products, and various automotive applications. Herein, the effect of FDM fabrication conditions on the flexural creep stiffness behavior of polycarbonate-acrylonitrile-butadiene-styrene processed parts was investigated. A relatively new class of experimental design called "definitive screening design" was adopted for this investigation. The effects of process variables on flexural creep stiffness behavior were monitored, and the best suited quadratic polynomial model with high coefficient of determination ( R 2) value was developed. This study highlights the value of response surface definitive screening design in optimizing properties for the products and materials, and it demonstrates its role and potential application in material processing and additive manufacturing.

Recent advances in the development of aerospace materials

NASA Astrophysics Data System (ADS)

Zhang, Xuesong; Chen, Yongjun; Hu, Junling

2018-02-01

In recent years, much progress has been made on the development of aerospace materials for structural and engine applications. Alloys, such as Al-based alloys, Mg-based alloys, Ti-based alloys, and Ni-based alloys, are developed for aerospace industry with outstanding advantages. Composite materials, the innovative materials, are taking more and more important roles in aircrafts. However, recent aerospace materials still face some major challenges, such as insufficient mechanical properties, fretting wear, stress corrosion cracking, and corrosion. Consequently, extensive studies have been conducted to develop the next generation aerospace materials with superior mechanical performance and corrosion resistance to achieve improvements in both performance and life cycle cost. This review focuses on the following topics: (1) materials requirements in design of aircraft structures and engines, (2) recent advances in the development of aerospace materials, (3) challenges faced by recent aerospace materials, and (4) future trends in aerospace materials.

Advances in research on 2D and 3D graphene-based supercapacitors

NASA Astrophysics Data System (ADS)

Mensing, Johannes Ph.; Poochai, Chatwarin; Kerdpocha, Sadanan; Sriprachuabwong, Chakrit; Wisitsoraat, Anurat; Tuantranont, Adisorn

2017-09-01

Graphene-based materials in two-dimensional (2D) and three-dimensional (3D) configurations are promising as electrode materials for supercapacitors due to their large surface area, excellent electrical conductivity, high electrochemical activity and high stability. In this article recent advances in research on 2D and 3D graphene-based materials for supercapacitor electrodes are reviewed extensively in aspects of fabrication methods and electrochemical performances. From the survey, the performance of 2D and 3D graphene-based materials could be significantly enhanced by employing nanostructures of metal oxides, metals and polymers as well as doping graphene with hetero atoms such as nitrogen and boron. In addition, the charge storage performances were found to depend greatly on materials, preparation method and structural configuration. With similar material components, 3D graphene-based networks tended to exhibit superior supercapacitive performances. Therefore, future research should be focusing on further development of 3D graphene-based materials for supercapacitor applications. Invited talk at 5th Thailand International Nanotechnology Conference (Nano Thailand-2016), 27-29 November 2016, Nakhon Ratchasima, Thailand.

Post-Flight Evaluation of PICA and PICA-X - Comparisons of the Stardust SRC and Space-X Dragon 1 Forebody Heatshield Materials

NASA Technical Reports Server (NTRS)

Stackpoole, M.; Kao, D.; Qu, V.; Gonzales, G.

2013-01-01

Phenolic Impregnated Carbon Ablator (PICA) was developed at NASA Ames Research Center. As a thermal protection material, PICA has the advantages of being able to withstand high heat fluxes with a relatively low density. This ablative material was used as the forebody heat shield material for the Stardust sample return capsule, which re-entered the Earths atmosphere in 2006. Based on PICA, SpaceX developed a variant, PICA-X, and used it as the heat shield material for its Dragon spacecraft, which successfully orbited the Earth and re-entered the atmosphere during the COTS Demo Flight 1 in 2010. Post-flight analysis was previously performed on the Stardust PICA heat shield material. Similarly, a near-stagnation core was obtained from the post-flight Dragon 1 heat shield, which was retrieved from the Pacific Ocean. Materials testing and analyses were performed on the core to evaluate its ablation performance and post-flight properties. Comparisons between PICA and PICA-X are made where applicable. Stardust and Dragon offer rare opportunities to evaluate materials post-flight - this data is beneficial in understanding material performance and also improves modeling capabilities.

Effects of BOX engineering on analogue/RF and circuit performance of InGaAs-OI-Si MOSFET

NASA Astrophysics Data System (ADS)

Maity, Subir Kr.; Pandit, Soumya

2017-11-01

InGaAs is an attractive choice as alternate channel material in n-channel metal oxide semiconductor transistor for high-performance applications. However, electrostatic integrity of such device is poor. In this paper, we present a comprehensive technology computer-aided design simulation-based study of the effect of scaling the thickness of the buried oxide (BOX) region and varying the dielectric constant of BOX material on the electrostatic integrity, analogue/radio frequency (RF) performance and circuit performance of InGaAs-on-Insulator device. Device with thin BOX layer gives better drain-induced barrier lowering performance which enhances output resistance. The carrier mobility remains almost constant with thinning of BOX layer up to certain value. By lowering the dielectric constant of the BOX material, it is further possible to improve the analogue and RF performance. Effect of BOX thickness scaling and role of BOX dielectric material on gain-frequency response of common source amplifier is also studied. It is observed that frequency response of the amplifier improves for thin BOX and with low dielectric constant-based material.

Kinetics of Materials at Extreme Conditions: Understanding the Time Dependent Approach to Equilibrium at MaRIE

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

Kraus, R. G.; Mcnabb, D.; Kumar, M.

The National Nuclear Security Agency has recently recognized that a long-term need exists to establish a stronger scientific basis for the assessment and qualification of materials and manufacturing processes for the nuclear stockpile and other national security applications. These materials may have undergone substantial changes with age, or may represent new materials that are being introduced because of difficulties associated with reusing or recreating materials used in original stockpile components. Also, with advancements in manufacturing methods, the NNSA anticipates opportunities for an enhanced range of control over fabricated components, an enhanced pace of materials development, and enhanced functionality. The developmentmore » of qualification standards for these new materials will require the ability to understand and control material characteristics that affect both mechanical and dynamic performance. A unique aspect for NNSA is that the performance requirements for materials are often set by system hydrodynamics, and these materials must perform in extreme environments and loading conditions. Thus, the scientific motivation is to understand “Matter-Radiation Interactions in Extremes (MaRIE).”« less

Nitrogen-Doped Single-Walled Carbon Nanohorns as a Cost-Effective Carbon Host toward High-Performance Lithium-Sulfur Batteries.

PubMed

Gulzar, Umair; Li, Tao; Bai, Xue; Colombo, Massimo; Ansaldo, Alberto; Marras, Sergio; Prato, Mirko; Goriparti, Subrahmanyam; Capiglia, Claudio; Proietti Zaccaria, Remo

2018-02-14

Nitrogen-doped single-walled carbon nanohorns (N-SWCNHs) are porous carbon material characterized by unique horn-shape structures with high surface areas and good conductivity. Moreover, they can be mass-produced (tons/year) using a novel proprietary process technology making them an attractive material for various industrial applications. One of the applications is the encapsulation of sulfur, which turns them as promising conductive host materials for lithium-sulfur batteries. Therefore, we explore for the first time the electrochemical performance of industrially produced N-SWCNHs as a sulfur-encapsulating conductive material. Fabrication of lithium-sulfur cells based on N-SWCNHs with sulfur composite could achieve a remarkable initial gravimetric capacity of 1650 mA h g -1 , namely equal to 98.5% of the theoretical capacity (1675 mA h g -1 ), with an exceptional sulfur content as high as 80% in weight. Using cyclic chronopotentiometry and impedance spectroscopy, we also explored the dissolution mechanism of polysulfides inside the electrolyte.

MoS 2-on-MXene Heterostructures as Highly Reversible Anode Materials for Lithium-Ion Batteries

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

Chen, Chi; Xie, Xiuqiang; Anasori, Babak

Two-dimensional (2D) heterostructured materials, combining the collective advantages of individual building blocks and synergistic properties, have spurred great interest as a new paradigm in materials science. The family of 2D transition-metal carbides and nitrides, MXenes, has emerged as an attractive platform to construct functional materials with enhanced performance for diverse applications. Here, we synthesized 2D MoS 2-on-MXene heterostructures through in situ sulfidation of Mo 2TiC 2Tx MXene. The computational results show that MoS 2-on-MXene heterostructures have metallic properties. Moreover, the presence of MXene leads to enhanced Li and Li2S adsorption during the intercalation and conversion reactions. These characteristics render themore » as-prepared MoS 2-on-MXene heterostructures stable Li-ion storage performance. In conclusion, this work paves the way to use MXene to construct 2D heterostructures for energy storage applications.« less

Blue emitting 1,8-naphthalimides with electron transport properties for organic light emitting diode applications

NASA Astrophysics Data System (ADS)

Ulla, Hidayath; Kiran, M. Raveendra; Garudachari, B.; Ahipa, T. N.; Tarafder, Kartick; Adhikari, Airody Vasudeva; Umesh, G.; Satyanarayan, M. N.

2017-09-01

In this article, the synthesis, characterization and use of two novel naphthalimides as electron-transporting emitter materials for organic light emitting diode (OLED) applications are reported. The molecules were obtained by substituting electron donating chloro-phenoxy group at the C-4 position. A detailed optical, thermal, electrochemical and related properties were systematically studied. Furthermore, theoretical calculations (DFT) were performed to get a better understanding of the electronic structures. The synthesized molecules were used as electron transporters and emitters in OLEDs with three different device configurations. The devices with the molecules showed blue emission with efficiencies of 1.89 cdA-1, 0.98 lmW-1, 0.71% at 100 cdm-2. The phosphorescent devices with naphthalimides as electron transport materials displayed better performance in comparison to the device without any electron transporting material and were analogous with the device using standard electron transporting material, Alq3. The results demonstrate that the naphthalimides could play a significant part in the progress of OLEDs.

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

Liu, Jia

Biorefineries convert biomass into many useful intermediates. For bio-based products to be used for fuel, energy, chemical, and many other applications, water needs to be removed from these aqueous products. Membrane separation technologies can significantly reduce separation energy consumption compared with conventional separation processes such as distillation. Nanoporous inorganic membranes have superior pervaporation performance with excellent organic fouling resistance. However, their commercial applications are limited due to high membrane costs and poor production reproducibility. A novel cost-effective inorganic membrane fabrication technology has been developed with low cost materials and using an advanced membrane fabrication technology. Low cost precursor material formulationmore » was successfully developed with desired material properties for membrane fabrication. An advanced membrane fabrication process was developed using the novel membrane materials to enable the fabrication of separation membranes of various geometries. The structural robustness and separation performance of the low cost inorganic membranes were evaluated. The novel inorganic membranes demonstrated high structural integrity and were effective in pervaporation removal of water.« less

Self-assembled cellulose materials for biomedicine: A review.

PubMed

Yang, Jisheng; Li, Jinfeng

2018-02-01

Cellulose-based materials have reached a growing interest for the improvement of biomedicine, due to their good biocompatibility, biodegradability, and low toxicity. Self-assembly is a spontaneous process by which organized structures with particular functions and properties could be obtained without additional complicated processing steps. This article describes the modifications, properties and applications of cellulose and its derivatives, which including a detailed review of representative types of solvents such as NMMO, DMAc/LiCl, some molten salt hydrates, some aqueous solutions of metal complexes, ionic liquids and NaOH-water system etc. The modifications were frequently performed by esterification, etherification, ATRP, RAFT, ROP and other novel methods. Stimuli-responsive cellulose-based materials, such as temperature-, pH-, light- and redox-responsive, were synthesized for their superior performance. Additionally, the applications of cellulose-based materials which can self-assemble into micelles, vesicles and other aggregates, for drug/gene delivery, bioimaging, biosensor, are also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

MoS 2-on-MXene Heterostructures as Highly Reversible Anode Materials for Lithium-Ion Batteries

DOE PAGES

Chen, Chi; Xie, Xiuqiang; Anasori, Babak; ...

2018-01-02

Two-dimensional (2D) heterostructured materials, combining the collective advantages of individual building blocks and synergistic properties, have spurred great interest as a new paradigm in materials science. The family of 2D transition-metal carbides and nitrides, MXenes, has emerged as an attractive platform to construct functional materials with enhanced performance for diverse applications. Here, we synthesized 2D MoS 2-on-MXene heterostructures through in situ sulfidation of Mo 2TiC 2Tx MXene. The computational results show that MoS 2-on-MXene heterostructures have metallic properties. Moreover, the presence of MXene leads to enhanced Li and Li2S adsorption during the intercalation and conversion reactions. These characteristics render themore » as-prepared MoS 2-on-MXene heterostructures stable Li-ion storage performance. In conclusion, this work paves the way to use MXene to construct 2D heterostructures for energy storage applications.« less

Layered conductive polymer on nylon membrane templates for high performance, thin-film supercapacitor electrodes

NASA Astrophysics Data System (ADS)

Shi, HaoTian Harvey; Naguib, Hani E.

2016-04-01

Flexible Thin-film Electrochemical Capacitors (ECs) are emerging technology that plays an important role as energy supply for various electronics system for both present era and the future. Intrinsically conductive polymers (ICPs) are promising pseudo-capacitive materials as they feature both good electrical conductivity and high specific capacitance. This study focuses on the construction and characterization of ultra-high surface area porous electrodes based on coating of nano-sized conductive polymer materials on nylon membrane templates. Herein, a novel nano-engineered electrode material based on nylon membranes was presented, which allows the creation of super-capacitor devices that is capable of delivering competitive performance, while maintaining desirable mechanical characteristics. With the formation of a highly conductive network with the polyaniline nano-layer, the electrical conductivity was also increased dramatically to facilitate the charge transfer process. Cyclic voltammetry and specific capacitance results showed promising application of this type of composite materials for future smart textile applications.

Multifunctional composites for energy storage

NASA Astrophysics Data System (ADS)

Shuvo, Mohammad Arif I.; Karim, Hasanul; Rajib, Md; Delfin, Diego; Lin, Yirong

2014-03-01

Electrochemical super-capacitors have become one of the most important topics in both academia and industry as novel energy storage devices because of their high power density, long life cycles, and high charge/discharge efficiency. Recently, there has been an increasing interest in the development of multifunctional structural energy storage devices such as structural super-capacitors for applications in aerospace, automobiles and portable electronics. These multifunctional structural super-capacitors provide lighter structures combining energy storage and load bearing functionalities. Due to their superior materials properties, carbon fiber composites have been widely used in structural applications for aerospace and automotive industries. Besides, carbon fiber has good electrical conductivity which will provide lower equivalent series resistance; therefore, it can be an excellent candidate for structural energy storage applications. Hence, this paper is focused on performing a pilot study for using nanowire/carbon fiber hybrids as building materials for structural energy storage materials; aiming at enhancing the charge/discharge rate and energy density. This hybrid material combines the high specific surface area of carbon fiber and pseudo-capacitive effect of metal oxide nanowires which were grown hydrothermally in an aligned fashion on carbon fibers. The aligned nanowire array could provide a higher specific surface area that leads to high electrode-electrolyte contact area and fast ion diffusion rates. Scanning Electron Microscopy (SEM) and XRay Diffraction (XRD) measurements were used for the initial characterization of this nanowire/carbon fiber hybrid material system. Electrochemical testing has been performed using a potentio-galvanostat. The results show that gold sputtered nanowire hybrid carbon fiber provides 65.9% better performance than bare carbon fiber cloth as super-capacitor.

Smart nickel oxide materials for the applications of energy efficiency and storage

NASA Astrophysics Data System (ADS)

Lin, Feng

The present dissertation studies nickel oxide-based materials for the application of electrochromic windows and lithium-air batteries. The materials were fabricated via radio frequency magnetron sputtering and subsequently post-treated with thermal evaporation and ozone exposure. The strategies to improve electrochromic performance of nickel oxide materials were investigated including compositional control, morphology tuning, modification of electronic structure and interface engineering (i.e., Li2O 2, graphene). The electrochemical properties of the resulting materials were characterized in lithium ion electrolytes. Extremely high performing nickel oxide-based electrochromic materials were obtained in terms of optical modulation, switching kinetics, bleached-state transparency and durability, which promise the implementation of these materials for practical smart windows. With the aid of advanced synchrotron X-ray absorption spectroscopy, it is reported for the first time that the electrochromic effect in multicomponent nickel oxide-based materials arises from the reversible formation of hole states in the NiO6 cluster accompanying with the reversible formation of Li2O2. The reversible formation of Li2O 2 was successfully leveraged with the study of electro-catalysts and cathode materials for lithium-air batteries. The reversibility of Li 2O2 was thoroughly investigated using soft X-ray absorption spectroscopy and theoretical simulation, which substantiates the promise of using electrochromic films as electro-catalysts and/or cathode materials in lithium-air batteries.

High-performance organic light-emitting diodes comprising ultrastable glass layers

PubMed Central

Rodríguez-Viejo, Javier

2018-01-01

Organic light-emitting diodes (OLEDs) are one of the key solid-state light sources for various applications including small and large displays, automotive lighting, solid-state lighting, and signage. For any given commercial application, OLEDs need to perform at their best, which is judged by their device efficiency and operational stability. We present OLEDs that comprise functional layers fabricated as ultrastable glasses, which represent the thermodynamically most favorable and, thus, stable molecular conformation achievable nowadays in disordered solids. For both external quantum efficiencies and LT70 lifetimes, OLEDs with four different phosphorescent emitters show >15% enhancements over their respective reference devices. The only difference to the latter is the growth condition used for ultrastable glass layers that is optimal at about 85% of the materials’ glass transition temperature. These improvements are achieved through neither material refinements nor device architecture optimization, suggesting a general applicability of this concept to maximize the OLED performance, no matter which specific materials are used. PMID:29806029

Cost-effective lightweight mirrors for aerospace and defense

NASA Astrophysics Data System (ADS)

Woodard, Kenneth S.; Comstock, Lovell E.; Wamboldt, Leonard; Roy, Brian P.

2015-05-01

The demand for high performance, lightweight mirrors was historically driven by aerospace and defense (A&D) but now we are also seeing similar requirements for commercial applications. These applications range from aerospace-like platforms such as small unmanned aircraft for agricultural, mineral and pollutant aerial mapping to an eye tracking gimbaled mirror for optometry offices. While aerospace and defense businesses can often justify the high cost of exotic, low density materials, commercial products rarely can. Also, to obtain high performance with low overall optical system weight, aspheric surfaces are often prescribed. This may drive the manufacturing process to diamond machining thus requiring the reflective side of the mirror to be a diamond machinable material. This paper summarizes the diamond machined finishing and coating of some high performance, lightweight designs using non-exotic substrates to achieve cost effective mirrors. The results indicate that these processes can meet typical aerospace and defense requirements but may also be competitive in some commercial applications.

Wood-Based Nanotechnologies toward Sustainability.

PubMed

Jiang, Feng; Li, Tian; Li, Yiju; Zhang, Ying; Gong, Amy; Dai, Jiaqi; Hitz, Emily; Luo, Wei; Hu, Liangbing

2018-01-01

With over 30% global land coverage, the forest is one of nature's most generous gifts to human beings, providing shelters and materials for all living beings. Apart from being sustainable, renewable, and biodegradable, wood and its derivative materials are also extremely fascinating from a materials aspect, with numerous advantages including porous and hierarchical structure, excellent mechanical performance, and versatile chemistry. Here, strategies for designing novel wood-based materials via advanced nanotechnologies are summarized, including both the controllable bottom-up assembly from the highly crystalline nanocellulose building block and the more efficient top-down approaches directly from wood. Beyond material design, recent advances regarding the sustainable applications of these novel wood-based materials are also presented, focusing on areas that are traditionally dominated by man-made nonrenewable materials such as plastic, glass, and metals, as well as more advanced applications in the areas of energy storage, wastewater treatment and solar-steam-assisted desalination. With all recent progress pertaining to materials' design and sustainable applications presented, a vision for the future engineering of wood-based materials to promote continuous and healthy progress toward true sustainability is outlined. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biodegradable Shape Memory Polymers in Medicine.

PubMed

Peterson, Gregory I; Dobrynin, Andrey V; Becker, Matthew L

2017-11-01

Shape memory materials have emerged as an important class of materials in medicine due to their ability to change shape in response to a specific stimulus, enabling the simplification of medical procedures, use of minimally invasive techniques, and access to new treatment modalities. Shape memory polymers, in particular, are well suited for such applications given their excellent shape memory performance, tunable materials properties, minimal toxicity, and potential for biodegradation and resorption. This review provides an overview of biodegradable shape memory polymers that have been used in medical applications. The majority of biodegradable shape memory polymers are based on thermally responsive polyesters or polymers that contain hydrolyzable ester linkages. These materials have been targeted for use in applications pertaining to embolization, drug delivery, stents, tissue engineering, and wound closure. The development of biodegradable shape memory polymers with unique properties or responsiveness to novel stimuli has the potential to facilitate the optimization and development of new medical applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Performance investigation of bandgap, gate material work function and gate dielectric engineered TFET with device reliability improvement

NASA Astrophysics Data System (ADS)

Raad, Bhagwan Ram; Nigam, Kaushal; Sharma, Dheeraj; Kondekar, P. N.

2016-06-01

This script features a study of bandgap, gate material work function and gate dielectric engineering for enhancement of DC and Analog/RF performance, reduction in the hot carriers effect (HCEs) and drain induced barrier lowering (DIBL) for better device reliability. In this concern, the use of band gap and gate material work function engineering improves the device performance in terms of the ON-state current and suppressed ambipolar behaviour with maintaining the low OFF-state current. With these advantages, the use of gate material work function engineering imposes restriction on the high frequency performance due to increment in the parasitic capacitances and also introduces the hot carrier effects. Hence, the gate dielectric engineering with bandgap and gate material work function engineering are used in this paper to overcome the cons of the gate material work function engineering by obtaining a superior performance in terms of the current driving capability, ambipolar conduction, HCEs, DIBL and high frequency parameters of the device for ultra-low power applications. Finally, the optimization of length for different work function is performed to get the best out of this.

Robust superhydrophobic bridged silsesquioxane aerogels with tunable performances and their applications.

PubMed

Wang, Zhen; Wang, Dong; Qian, Zhenchao; Guo, Jing; Dong, Haixia; Zhao, Ning; Xu, Jian

2015-01-28

Aerogels are a family of highly porous materials whose applications are commonly restricted by poor mechanical properties. Herein, thiol-ene chemistry is employed to synthesize a series of novel bridged silsesquioxane (BSQ) precursors with various alkoxy groups. On the basis of the different hydrolyzing rates of the methoxy and ethoxy groups, robust superhydrophobic BSQ aerogels with tailorable morphology and mechanical performances have been prepared. The flexible thioether bridge contributes to the robustness of the as-formed aerogels, and the property can be tuned on the basis of the distinct combinations of alkoxy groups with the density of the aerogels almost unchanged. To the best of our knowledge, the lowest density among the ambient pressure dried aerogels is obtained. Further, potential application of the aerogels for oil/water separation and acoustic materials has also been presented.

First-Principles Calculations of Electronic, Optical, and Transport Properties of Materials for Energy Applications

NASA Astrophysics Data System (ADS)

Shi, Guangsha

Solar electricity is a reliable and environmentally friendly method of sustainable energy production and a realistic alternative to conventional fossil fuels. Moreover, thermoelectric energy conversion is a promising technology for solid-state refrigeration and efficient waste-heat recovery. Predicting and optimizing new photovoltaic and thermoelectric materials composed of Earth-abundant elements that exceed the current state of the art, and understanding how nanoscale structuring and ordering improves their energy conversion efficiency pose a challenge for materials scientists. I approach this challenge by developing and applying predictive high-performance computing methods to guide research and development of new materials for energy-conversion applications. Advances in computer-simulation algorithms and high-performance computing resources promise to speed up the development of new compounds with desirable properties and significantly shorten the time delay between the discovery of new materials and their commercial deployment. I present my calculated results on the extraordinary properties of nanostructured semiconductor materials, including strong visible-light absorbance in nanoporous silicon and few-layer SnSe and GeSe. These findings highlight the capability of nanoscale structuring and ordering to improve the performance of Earth-abundant materials compared to their bulk counterparts for solar-cell applications. I also successfully identified the dominant mechanisms contributing to free-carrier absorption in n-type silicon. My findings help evaluate the impact of the energy loss from this absorption mechanism in doped silicon and are thus important for the design of silicon solar cells. In addition, I calculated the thermoelectric transport properties of p-type SnSe, a bulk material with a record thermoelectric figure of merit. I predicted the optimal temperatures and free-carrier concentrations for thermoelectric energy conversion, as well the theoretical upper limit of the figure of merit. I also determined the electronic structures and thermoelectric properties of Mg2Si, Mg2Ge, and Mg2Sn, a family of Earth-abundant thermoelectric compounds. I uncovered the importance of quasiparticle corrections and the proper treatment of pseudopotentials in the determination of the band gaps and the thermoelectric transport properties at high temperatures. The methods and codes I developed in my research form a general predictive toolbox for the design and optimization of the functional properties of materials for energy applications.

Multi-scale theory-assisted nano-engineering of plasmonic-organic hybrid electro-optic device performance

NASA Astrophysics Data System (ADS)

Elder, Delwin L.; Johnson, Lewis E.; Tillack, Andreas F.; Robinson, Bruce H.; Haffner, Christian; Heni, Wolfgang; Hoessbacher, Claudia; Fedoryshyn, Yuriy; Salamin, Yannick; Baeuerle, Benedikt; Josten, Arne; Ayata, Masafumi; Koch, Ueli; Leuthold, Juerg; Dalton, Larry R.

2018-02-01

Multi-scale (correlated quantum and statistical mechanics) modeling methods have been advanced and employed to guide the improvement of organic electro-optic (OEO) materials, including by analyzing electric field poling induced electro-optic activity in nanoscopic plasmonic-organic hybrid (POH) waveguide devices. The analysis of in-device electro-optic activity emphasizes the importance of considering both the details of intermolecular interactions within organic electro-optic materials and interactions at interfaces between OEO materials and device architectures. Dramatic improvement in electro-optic device performance-including voltage-length performance, bandwidth, energy efficiency, and lower optical losses have been realized. These improvements are critical to applications in telecommunications, computing, sensor technology, and metrology. Multi-scale modeling methods illustrate the complexity of improving the electro-optic activity of organic materials, including the necessity of considering the trade-off between improving poling-induced acentric order through chromophore modification and the reduction of chromophore number density associated with such modification. Computational simulations also emphasize the importance of developing chromophore modifications that serve multiple purposes including matrix hardening for enhanced thermal and photochemical stability, control of matrix dimensionality, influence on material viscoelasticity, improvement of chromophore molecular hyperpolarizability, control of material dielectric permittivity and index of refraction properties, and control of material conductance. Consideration of new device architectures is critical to the implementation of chipscale integration of electronics and photonics and achieving the high bandwidths for applications such as next generation (e.g., 5G) telecommunications.

Processing and Material Characterization of Continuous Basalt Fiber Reinforced Ceramic Matrix Composites Using Polymer Derived Ceramics.

NASA Technical Reports Server (NTRS)

Cox, Sarah B.

2014-01-01

The need for high performance vehicles in the aerospace industry requires materials which can withstand high loads and high temperatures. New developments in launch pads and infrastructure must also be made to handle this intense environment with lightweight, reusable, structural materials. By using more functional materials, better performance can be seen in the launch environment, and launch vehicle designs which have not been previously used can be considered. The development of high temperature structural composite materials has been very limited due to the high cost of the materials and the processing needed. Polymer matrix composites can be used for temperatures up to 260C. Ceramics can take much higher temperatures, but they are difficult to produce and form in bulk volumes. Polymer Derived Ceramics (PDCs) begin as a polymer matrix, allowing a shape to be formed and cured and then to be pyrolized in order to obtain a ceramic with the associated thermal and mechanical properties. The use of basalt in structural and high temperature applications has been under development for over 50 years, yet there has been little published research on the incorporation of basalt fibers as a reinforcement in the composites. In this study, continuous basalt fiber reinforced PDCs have been fabricated and tested for the applicability of this composite system as a high temperature structural composite material. The oxyacetylene torch testing and three point bend testing have been performed on test panels and the test results are presented.

Lifetime laser damage performance of β -Ga2O3 for high power applications

NASA Astrophysics Data System (ADS)

Yoo, Jae-Hyuck; Rafique, Subrina; Lange, Andrew; Zhao, Hongping; Elhadj, Selim

2018-03-01

Gallium oxide (Ga2O3) is an emerging wide bandgap semiconductor with potential applications in power electronics and high power optical systems where gallium nitride and silicon carbide have already demonstrated unique advantages compared to gallium arsenide and silicon-based devices. Establishing the stability and breakdown conditions of these next-generation materials is critical to assessing their potential performance in devices subjected to large electric fields. Here, using systematic laser damage performance tests, we establish that β-Ga2O3 has the highest lifetime optical damage performance of any conductive material measured to date, above 10 J/cm2 (1.4 GW/cm2). This has direct implications for its use as an active component in high power laser systems and may give insight into its utility for high-power switching applications. Both heteroepitaxial and bulk β-Ga2O3 samples were benchmarked against a heteroepitaxial gallium nitride sample, revealing an order of magnitude higher optical lifetime damage threshold for β-Ga2O3. Photoluminescence and Raman spectroscopy results suggest that the exceptional damage performance of β-Ga2O3 is due to lower absorptive defect concentrations and reduced epitaxial stress.

Design and Optimization of Composite Automotive Hatchback Using Integrated Material-Structure-Process-Performance Method

NASA Astrophysics Data System (ADS)

Yang, Xudong; Sun, Lingyu; Zhang, Cheng; Li, Lijun; Dai, Zongmiao; Xiong, Zhenkai

2018-03-01

The application of polymer composites as a substitution of metal is an effective approach to reduce vehicle weight. However, the final performance of composite structures is determined not only by the material types, structural designs and manufacturing process, but also by their mutual restrict. Hence, an integrated "material-structure-process-performance" method is proposed for the conceptual and detail design of composite components. The material selection is based on the principle of composite mechanics such as rule of mixture for laminate. The design of component geometry, dimension and stacking sequence is determined by parametric modeling and size optimization. The selection of process parameters are based on multi-physical field simulation. The stiffness and modal constraint conditions were obtained from the numerical analysis of metal benchmark under typical load conditions. The optimal design was found by multi-discipline optimization. Finally, the proposed method was validated by an application case of automotive hatchback using carbon fiber reinforced polymer. Compared with the metal benchmark, the weight of composite one reduces 38.8%, simultaneously, its torsion and bending stiffness increases 3.75% and 33.23%, respectively, and the first frequency also increases 44.78%.

Strong, light, multifunctional fibers of carbon nanotubes with ultrahigh conductivity.

PubMed

Behabtu, Natnael; Young, Colin C; Tsentalovich, Dmitri E; Kleinerman, Olga; Wang, Xuan; Ma, Anson W K; Bengio, E Amram; ter Waarbeek, Ron F; de Jong, Jorrit J; Hoogerwerf, Ron E; Fairchild, Steven B; Ferguson, John B; Maruyama, Benji; Kono, Junichiro; Talmon, Yeshayahu; Cohen, Yachin; Otto, Marcin J; Pasquali, Matteo

2013-01-11

Broader applications of carbon nanotubes to real-world problems have largely gone unfulfilled because of difficult material synthesis and laborious processing. We report high-performance multifunctional carbon nanotube (CNT) fibers that combine the specific strength, stiffness, and thermal conductivity of carbon fibers with the specific electrical conductivity of metals. These fibers consist of bulk-grown CNTs and are produced by high-throughput wet spinning, the same process used to produce high-performance industrial fibers. These scalable CNT fibers are positioned for high-value applications, such as aerospace electronics and field emission, and can evolve into engineered materials with broad long-term impact, from consumer electronics to long-range power transmission.

High-Performance WSe2 Complementary Metal Oxide Semiconductor Technology and Integrated Circuits.

PubMed

Yu, Lili; Zubair, Ahmad; Santos, Elton J G; Zhang, Xu; Lin, Yuxuan; Zhang, Yuhao; Palacios, Tomás

2015-08-12

Because of their extraordinary structural and electrical properties, two-dimensional materials are currently being pursued for applications such as thin-film transistors and integrated circuit. One of the main challenges that still needs to be overcome for these applications is the fabrication of air-stable transistors with industry-compatible complementary metal oxide semiconductor (CMOS) technology. In this work, we experimentally demonstrate a novel high performance air-stable WSe2 CMOS technology with almost ideal voltage transfer characteristic, full logic swing and high noise margin with different supply voltages. More importantly, the inverter shows large voltage gain (∼38) and small static power (picowatts), paving the way for low power electronic system in 2D materials.

Cellulose-Based Biomimetics and Their Applications.

PubMed

Almeida, Ana P C; Canejo, João P; Fernandes, Susete N; Echeverria, Coro; Almeida, Pedro L; Godinho, Maria H

2018-05-01

Nature has been producing cellulose since long before man walked the surface of the earth. Millions of years of natural design and testing have resulted in cellulose-based structures that are an inspiration for the production of synthetic materials based on cellulose with properties that can mimic natural designs, functions, and properties. Here, five sections describe cellulose-based materials with characteristics that are inspired by gratings that exist on the petals of the plants, structurally colored materials, helical filaments produced by plants, water-responsive materials in plants, and environmental stimuli-responsive tissues found in insects and plants. The synthetic cellulose-based materials described herein are in the form of fibers and films. Fascinating multifunctional materials are prepared from cellulose-based liquid crystals and from composite cellulosic materials that combine functionality with structural performance. Future and recent applications are outlined. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preliminary investigation and application of alternate dry gas seal face materials{copyright}

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

Evenson, R.; Peterson, R.; Hanson, R.

1994-01-01

Traditional seal mating ring materials such as tungsten carbide (WC) are commonly used in high pressure centrifugal gas compressor dry gas (gas lubricating film) seal applications. Although these materials possess desirable properties for minimizing thermal distortion and deformation when subjected to pressure and centrifugal force, they have low toughness, i.e., they are brittle and have poor resistance to thermal shock. It has been found that these materials are easily heat checked during seal face touchdown. Heat checking as well as other crack indications inherent in these materials can quickly propagate, resulting in a catastrophic seal ring failure. In this paper,more » an investigation of alternate seal face materials is described. Two ductile, nitrided, low ferrous materials proved to be readily manufacturable into dry gas seal rings and performed comparably to tungsten carbide in natural gas service. 10 refs., 13 figs., 5 tabs.« less

Functionalization of graphene for efficient energy conversion and storage.

PubMed

Dai, Liming

2013-01-15

As global energy consumption accelerates at an alarming rate, the development of clean and renewable energy conversion and storage systems has become more important than ever. Although the efficiency of energy conversion and storage devices depends on a variety of factors, their overall performance strongly relies on the structure and properties of the component materials. Nanotechnology has opened up new frontiers in materials science and engineering to meet this challenge by creating new materials, particularly carbon nanomaterials, for efficient energy conversion and storage. As a building block for carbon materials of all other dimensionalities (such as 0D buckyball, 1D nanotube, 3D graphite), the two-dimensional (2D) single atomic carbon sheet of graphene has emerged as an attractive candidate for energy applications due to its unique structure and properties. Like other materials, however, a graphene-based material that possesses desirable bulk properties rarely features the surface characteristics required for certain specific applications. Therefore, surface functionalization is essential, and researchers have devised various covalent and noncovalent chemistries for making graphene materials with the bulk and surface properties needed for efficient energy conversion and storage. In this Account, I summarize some of our new ideas and strategies for the controlled functionalization of graphene for the development of efficient energy conversion and storage devices, such as solar cells, fuel cells, supercapacitors, and batteries. The dangling bonds at the edge of graphene can be used for the covalent attachment of various chemical moieties while the graphene basal plane can be modified via either covalent or noncovalent functionalization. The asymmetric functionalization of the two opposite surfaces of individual graphene sheets with different moieties can lead to the self-assembly of graphene sheets into hierarchically structured materials. Judicious application of these site-selective reactions to graphene sheets has opened up a rich field of graphene-based energy materials with enhanced performance in energy conversion and storage. These results reveal the versatility of surface functionalization for making sophisticated graphene materials for energy applications. Even though many covalent and noncovalent functionalization methods have already been reported, vast opportunities remain for developing novel graphene materials for highly efficient energy conversion and storage systems.

Emerging and potential opportunities for 2D flexible nanoelectronics

NASA Astrophysics Data System (ADS)

Zhu, Weinan; Park, Saungeun; Akinwande, Deji

2016-05-01

The last 10 years have seen the emergence of two-dimensional (2D) nanomaterials such as graphene, transition metal dichalcogenides (TMDs), and black phosphorus (BP) among the growing portfolio of layered van der Waals thin films. Graphene, the prototypical 2D material has advanced rapidly in device, circuit and system studies that has resulted in commercial large-area applications. In this work, we provide a perspective of the emerging and potential translational applications of 2D materials including semiconductors, semimetals, and insulators that comprise the basic material set for diverse nanosystems. Applications include RF transceivers, smart systems, the so-called internet of things, and neurotechnology. We will review the DC and RF electronic performance of graphene and BP thin film transistors. 2D materials at sub-um channel length have so far enabled cut-off frequencies from baseband to 100GHz suitable for low-power RF and sub-THz concepts.

Carbon fiber composites application in ITER plasma facing components

NASA Astrophysics Data System (ADS)

Barabash, V.; Akiba, M.; Bonal, J. P.; Federici, G.; Matera, R.; Nakamura, K.; Pacher, H. D.; Rödig, M.; Vieider, G.; Wu, C. H.

1998-10-01

Carbon Fiber Composites (CFCs) are one of the candidate armour materials for the plasma facing components of the International Thermonuclear Experimental Reactor (ITER). For the present reference design, CFC has been selected as armour for the divertor target near the plasma strike point mainly because of unique resistance to high normal and off-normal heat loads. It does not melt under disruptions and might have higher erosion lifetime in comparison with other possible armour materials. Issues related to CFC application in ITER are described in this paper. They include erosion lifetime, tritium codeposition with eroded material and possible methods for the removal of the codeposited layers, neutron irradiation effect, development of joining technologies with heat sink materials, and thermomechanical performance. The status of the development of new advanced CFCs for ITER application is also described. Finally, the remaining R&D needs are critically discussed.

Organic Synthetic Advanced Materials for Optoelectronic and Energy Applications (at National Sun Yat-sen University) 

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

Yen, Hung-Ju

These slides cover Hung-Ju Yen's recent work in the synthesis and structural design of functional materials, which were further used for optoelectronic and energy applications, such as lithium ion battery, solar cell, LED, electrochromic, and fuel cells. This was for a job interview at National Sun Yat-sen University. The following topics are detailed: current challenges for lithium-ion batteries; graphene, graphene oxide and nanographene; nanographenes with various functional groups; fine tune d-spacing through organic synthesis: varying functional group; schematic view of LIBs; nanographenes as LIB anode; rate performance (charging-discharging); electrochromic technology; electrochromic materials; advantages of triphenylamine; requirement of electrochromic materials formore » practical applications; low driving voltage and long cycle life; increasing the electroactive sites by multi-step synthetic procedures; synthetic route to starburst triarylamine-based polyamide; electrochromism ranging from visible to NIR region; transmissive to black electrochromism; RGB and CMY electrochromism.« less

Thermoelectric efficiency of (1 - x)(GeTe) x(Bi2Se0.2Te2.8) and implementation into highly performing thermoelectric power generators.

PubMed

Koenig, J; Winkler, M; Dankwort, T; Hansen, A-L; Pernau, H-F; Duppel, V; Jaegle, M; Bartholomé, K; Kienle, L; Bensch, W

2015-02-14

Here we report for the first time on a complete simulation assisted "material to module" development of a high performance thermoelectric generator (TEG) based on the combination of a phase change material and established thermoelectrics yielding the compositions (1 - x)(GeTe) x(Bi(2)Se(0.2)Te(2.8)). For the generator design our approach for benchmarking thermoelectric materials is demonstrated which is not restricted to the determination of the intrinsically imprecise ZT value but includes the implementation of the material into a TEG. This approach is enabling a much more reliable benchmarking of thermoelectric materials for TEG application. Furthermore we analyzed the microstructure and performance close to in-operandi conditions for two different compositions in order to demonstrate the sensitivity of the material against processing and thermal cycling. For x = 0.038 the microstructure of the as-prepared material remains unchanged, consequently, excellent and stable thermoelectric performance as prerequisites for TEG production was obtained. For x = 0.063 we observed strain phenomena for the pristine state which are released by the formation of planar defects after thermal cycling. Consequently the thermoelectric performance degrades significantly. These findings highlight a complication for deriving the correlation of microstructure and properties of thermoelectric materials in general.

Materials Science Experiments Under Microgravity - A Review of History, Facilities, and Future Opportunities

NASA Technical Reports Server (NTRS)

Stenzel, Ch.

2012-01-01

Materials science experiments have been a key issue already since the early days of research under microgravity conditions. A microgravity environment facilitates processing of metallic and semiconductor melts without buoyancy driven convection and sedimentation. Hence, crystal growth of semiconductors, solidification of metallic alloys, and the measurement of thermo-physical parameters are the major applications in the field of materials science making use of these dedicated conditions in space. In the last three decades a large number of successful experiments have been performed, mainly in international collaborations. In parallel, the development of high-performance research facilities and the technological upgrade of diagnostic and stimuli elements have also contributed to providing optimum conditions to perform such experiments. A review of the history of materials science experiments in space focussing on the development of research facilities is given. Furthermore, current opportunities to perform such experiments onboard ISS are described and potential future options are outlined.

Performance and cost of materials for lithium-based rechargeable automotive batteries

NASA Astrophysics Data System (ADS)

Schmuch, Richard; Wagner, Ralf; Hörpel, Gerhard; Placke, Tobias; Winter, Martin

2018-04-01

It is widely accepted that for electric vehicles to be accepted by consumers and to achieve wide market penetration, ranges of at least 500 km at an affordable cost are required. Therefore, significant improvements to lithium-ion batteries (LIBs) in terms of energy density and cost along the battery value chain are required, while other key performance indicators, such as lifetime, safety, fast-charging ability and low-temperature performance, need to be enhanced or at least sustained. Here, we review advances and challenges in LIB materials for automotive applications, in particular with respect to cost and performance parameters. The production processes of anode and cathode materials are discussed, focusing on material abundance and cost. Advantages and challenges of different types of electrolyte for automotive batteries are examined. Finally, energy densities and costs of promising battery chemistries are critically evaluated along with an assessment of the potential to fulfil the ambitious targets of electric vehicle propulsion.

Finite element analysis and simulation of rheological properties of bulk molding compound (BMC)

NASA Astrophysics Data System (ADS)

Ergin, M. Fatih; Aydin, Ismail

2013-12-01

Bulk molding compound (BMC) is one of the important composite materials with various engineering applications. BMC is a thermoset plastic resin blend of various inert fillers, fiber reinforcements, catalysts, stabilizers and pigments that form a viscous, molding compound. Depending on the end-use application, bulk molding compounds are formulated to achieve close dimensional control, flame and scratch resistance, electrical insulation, corrosion and stain resistance, superior mechanical properties, low shrink and color stability. Its excellent flow characteristics, dielectric properties, and flame resistance make this thermoset material well-suited to a wide variety of applications requiring precision in detail and dimensions as well as high performance. When a BMC is used for these purposes, the rheological behavior and properties of the BMC is the main concern. In this paper, finite element analysis of rheological properties of bulk molding composite material was studied. For this purpose, standard samples of composite material were obtained by means of uniaxial hot pressing. 3 point flexural tests were then carried out by using a universal testing machine. Finite element analyses were then performed with defined material properties within a specific constitutive material behavior. Experimental and numerical results were then compared. Good correlation between the numerical simulation and the experimental results was obtained. It was expected with this study that effects of various process parameters and boundary conditions on the rheological behavior of bulk molding compounds could be determined by means of numerical analysis without detailed experimental work.

Use of organic precursors and graphenes in the controlled synthesis of carbon-containing nanomaterials for energy storage and conversion.

PubMed

Yang, Shubin; Bachman, Robert E; Feng, Xinliang; Müllen, Klaus

2013-01-15

The development of high-performance electrochemical energy storage and conversion devices, including supercapacitors, lithium-ion batteries, and fuel cells, is an important step on the road to alternative energy technologies. Carbon-containing nanomaterials (CCNMs), defined here as pure carbon materials and carbon/metal (oxide, hydroxide) hybrids with structural features on the nanometer scale, show potential application in such devices. Because of their pronounced electrochemical activity, high chemical and thermal stability and low cost, researchers are interested in CCNMs to serve as electrodes in energy-related devices. Various all-carbon materials are candidates for electrochemical energy storage and conversion devices. Furthermore, carbon-based hybrid materials, which consist of a carbon component with metal oxide- or metal hydroxide-based nanostructures, offer the opportunity to combine the attractive properties of these two components and tune the behavior of the resulting materials. As such, the design and synthesis of CCNMs provide an attractive route for the construction of high-performance electrode materials. Studies in these areas have revealed that both the composition and the fabrication protocol employed in preparing CCNMs influence the morphology and microstructure of the resulting material and its electrochemical performance. Consequently, researchers have developed several synthesis strategies, including hard-templated, soft-templated, and template-free synthesis of CCNMs. In this Account, we focus on recent advances in the controlled synthesis of such CCNMs and the potential of the resulting materials for energy storage or conversion applications. The Account is divided into four major categories based on the carbon precursor employed in the synthesis: low molecular weight organic or organometallic molecules, hyperbranched or cross-linked polymers consisting of aromatic subunits, self-assembling discotic molecules, and graphenes. In each case, we highlight representative examples of CCNMs with both new nanostructures and electrochemical performance suitable for energy storage or conversion applications. In addition, this Account provides an overall perspective on the current state of efforts aimed at the controlled synthesis of CCNMs and identifies some of the remaining challenges.

New materials for polymer electrolyte membrane fuel cell current collectors

NASA Astrophysics Data System (ADS)

Hentall, Philip L.; Lakeman, J. Barry; Mepsted, Gary O.; Adcock, Paul L.; Moore, Jon M.

Polymer Electrolyte Membrane Fuel cells for automotive applications need to have high power density, and be inexpensive and robust to compete effectively with the internal combustion engine. Development of membranes and new electrodes and catalysts have increased power significantly, but further improvements may be achieved by the use of new materials and construction techniques in the manufacture of the bipolar plates. To show this, a variety of materials have been fabricated into flow field plates, both metallic and graphitic, and single fuel cell tests were conducted to determine the performance of each material. Maximum power was obtained with materials which had lowest contact resistance and good electrical conductivity. The performance of the best material was characterised as a function of cell compression and flow field geometry.

Experimental investigation of fiberglass sandwich composite bending behaviour after severe aging condition

NASA Astrophysics Data System (ADS)

Gambaro, Carla; Lertora, Enrico; Mandolfino, Chiara

2016-10-01

Fiber Reinforced Polymer (FRP) sandwich panels are increasing their application as structural and non-structural components in all kinds of construction. By varying the material and thickness of core and face sheets, it is possible to obtain sandwich structures with different properties and performance. In particular, their advantages as lightweight and high mechanical properties make them extremely suitable for the transport industry. One of the most critical aspects regarding composite materials for engineering application is their performance after hygrothermal aging. The panels used in this study are composed of low density core, made by thermosetting resin foam with microspheres and glass fibers rolled until obtaining the required thickness, and two face sheets of the same material but realized in high density. In this study, the authors focused on the bending behaviour of this kind of sandwich panel, as received and after severe aging cycles.

Double-shell CuS nanocages as advanced supercapacitor electrode materials

NASA Astrophysics Data System (ADS)

Guo, Jinxue; Zhang, Xinqun; Sun, Yanfang; Zhang, Xiaohong; Tang, Lin; Zhang, Xiao

2017-07-01

Metal sulfides hollow structures are advanced materials for energy storage applications of lithium-ion batteries and supercapacitors. However, constructing hollow metal sulfides with specific features, such as multi-shell and non-spherical shape, still remains great challenge. In this work, we firstly demonstrate the synthesis of CuS double-shell hollow nanocages using Cu2O nanocubes as precursors. The synthesis processes involve the repeated anion exchange reaction with Na2S and the controllable etching using hydrochloric acid. The whole synthesis processes are well revealed and the obtained double-shell CuS is tested as pseudocapacitive electrode material for supercapacitors. As expected, the CuS double-shell hollow nanocages deliver high specific capacitance, good rate performance and excellent cycling stability due to their unique nano-architecture. The present work contributes greatly to the exploration of hollow metal sulfides with complex architecture and non-spherical shape, as well as their promising application in high-performance electrochemical supercapacitors.

Electrical behaviour of carbon nanotubes under low-energy proton irradiation

NASA Astrophysics Data System (ADS)

Abbe, Elisabeth; Schüler, Tilman; Klosz, Stefan; Starruß, Elisa; Pilz, Wolfgang; Böttger, Roman; Kluge, Oliver; Schmiel, Tino; Tajmar, Martin

2017-11-01

Several applications for carbon nanotubes (CNT) have been proposed for space applications in the last years. However, their behaviour in the harsh space environment is mostly unknown. Energetic particles such as protons can influence the material degradation in space. This material damage could result in a system failure of space systems. Therefore it is necessary to investigate the performance of new materials under proton irradiation. Screen and jet printed disordered single-walled carbon nanotubes (SWNT), multi-walled carbon nanotubes (MWNT) and multi-walled carbon nanotubes/resin composites (ME) were exposed to 1 keV, 15 keV and 100 keV protons. The electrical behaviour of the CNT conductor paths was measured during the experiment. After this exposure, the CNTs were analyzed using Raman scattering and a scanning electron microscope (SEM). Their is a clear evidence that proton radiation can destroy carbon nanotubes and influence their electrical performance.

Friction Stir Welding of ODS and RAFM Steels

DOE PAGES

Yu, Zhenzhen; Feng, Zhili; Hoelzer, David; ...

2015-09-14

Advanced structural materials such as oxide dispersion strengthened steels and reduced-activation ferritic/martensitic steels are desired in fusion reactors as primary candidate materials for first wall and blanket structures, due to their excellent radiation and high-temperature creep resistance. However, their poor fusion weldability has been the major technical challenge limiting practical applications. For this reason, solid-state friction stir welding (FSW) has been considered for such applications. In this paper, the effect of FSW parameters on joining similar and dissimilar advanced structural steels was investigated. Scanning electron microscopy and electron backscatter diffraction methods were used to reveal the effects of FSW onmore » grain size, micro-texture distribution, and phase stability. Hardness mapping was performed to evaluate mechanical properties. Finally, post weld heat treatment was also performed to tailor the microstructure in the welds in order to match the weld zone mechanical properties to the base material.« less

A comparative study of layered transition metal oxide cathodes for application in sodium-ion battery.

PubMed

Hasa, Ivana; Buchholz, Daniel; Passerini, Stefano; Hassoun, Jusef

2015-03-11

Herein, we report a study on P-type layered sodium transition metal-based oxides with a general formula of NaxMO2 (M = Ni, Fe, Mn). We synthesize the materials via coprecipitation followed by annealing in air and rinsing with water, and we examine the electrodes as cathodes for sodium-ion batteries using a propylene carbonate-based electrolyte. We fully investigate the effect of the Ni-to-Fe ratio, annealing temperature, and sodium content on the electrochemical performances of the electrodes. The impact of these parameters on the structural and electrochemical properties of the materials is revealed by X-ray diffraction, scanning electron microscopy, and cyclic voltammetry, respectively. The suitability of this class of P-type materials for sodium battery application is finally demonstrated by cycling tests revealing an excellent electrochemical performance in terms of delivered capacity (i.e., about 200 mAh g(-1)) and charge-discharge efficiency (approaching 100%).

Stress corrosion resistant fasteners

NASA Technical Reports Server (NTRS)

Roach, T. A.

1985-01-01

A family of high performance aerospace fasteners made from corrosion resistant alloys for use in applications where corrosion and stress-corrosion cracking are of major concern are discussed. The materials discussed are mainly A-286, Inconel 718, MP35N and MP159. Most of the fasteners utilize cold worked and aged materials to achieve the desired properties. The fasteners are unique in that they provide a combination of high strength and immunity to stress corrosion cracking not previously attainable. A discussion of fastener stress corrosion failures is presented including a review of the history and a description of the mechanism. Case histories are presented to illustrate the problems which can arise when material selection is made without proper regard for the environmental conditions. Mechanical properties and chemical compositions are included for the fasteners discussed. Several aspects of the application of high performance corrosion resistant fasteners are discussed including galvanic compatibility and torque-tension relationships.

Application of smart materials for improved flight performance of military aircraft

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

Kudva, J.; Appa, K.; Martin, C.

1995-12-31

This paper discusses on-going work under an ARPA/WL contract to Northrop Grumman entitled {open_quotes}Smart Structures and Materials Development - Smart Wing.{close_quotes} The contract addresses the application of smart materials and smart Structures concepts to enhance the aerodynamic and maneuver performance of military aircraft. Various concepts for adaptive wing and control surfaces are being studied. Specifically, (a) wing span-wise twist control using built-in shape- memory alloy torquing mechanism and (b) cambered leading edge and trailing edge control surfaces using hybrid piezoelectric and SMA actuation, are being evaluated for a 20% model of a modem day fighter aircraft. The potential benefits ofmore » the designs include increased lift for short take-offs, improved high-speed maneuverability, and enhanced control surface effectiveness. These benefits will be quantified by testing the sub-scale model in a transonic wind tunnel next year.« less

Molecular Motions in Functional Self-Assembled Nanostructures

PubMed Central

Dhotel, Alexandre; Chen, Ziguang; Delbreilh, Laurent; Youssef, Boulos; Saiter, Jean-Marc; Tan, Li

2013-01-01

The construction of “smart” materials able to perform specific functions at the molecular scale through the application of various stimuli is highly attractive but still challenging. The most recent applications indicate that the outstanding flexibility of self-assembled architectures can be employed as a powerful tool for the development of innovative molecular devices, functional surfaces and smart nanomaterials. Structural flexibility of these materials is known to be conferred by weak intermolecular forces involved in self-assembly strategies. However, some fundamental mechanisms responsible for conformational lability remain unexplored. Furthermore, the role played by stronger bonds, such as coordination, ionic and covalent bonding, is sometimes neglected while they can be employed readily to produce mechanically robust but also chemically reversible structures. In this review, recent applications of structural flexibility and molecular motions in self-assembled nanostructures are discussed. Special focus is given to advanced materials exhibiting significant performance changes after an external stimulus is applied, such as light exposure, pH variation, heat treatment or electromagnetic field. The crucial role played by strong intra- and weak intermolecular interactions on structural lability and responsiveness is highlighted. PMID:23348927

60NiTi Intermetallic Material Evaluation for Lightweight and Corrosion Resistant Spherical Sliding Bearings for Aerospace Applications

NASA Technical Reports Server (NTRS)

DellaCorte, Christopher; Jefferson, Michael

2015-01-01

NASA Glenn Research Center and the Kamatics subsidiary of the Kaman Corporation conducted the experimental evaluation of spherical sliding bearings made with 60NiTi inner races. The goal of the project was to assess the feasibility of manufacturing lightweight, corrosion resistant bearings utilizing 60NiTi for aerospace and industrial applications. NASA produced the bearings in collaboration with Abbott Ball Corporation and Kamatics fabricated bearing assemblies utilizing their standard reinforced polymer liner material. The assembled bearings were tested in oscillatory motion at a load of 4.54kN (10,000 lb), according to the requirements of the plain bearing specification SAE AS81820. Several test bearings were exposed to hydraulic fluid or aircraft deicing fluid prior to and during testing. The results show that the 60NiTi bearings exhibit tribological performance comparable to conventional stainless steel (440C) bearings. Further, exposure of 60NiTi bearings to the contaminant fluids had no apparent performance effect. It is concluded that 60NiTi is a feasible bearing material for aerospace and industrial spherical bearing applications.

Nanomoulding of Functional Materials, a Versatile Complementary Pattern Replication Method to Nanoimprinting

PubMed Central

Battaglia, Corsin; Söderström, Karin; Escarré, Jordi; Haug, Franz-Josef; Despeisse, Matthieu; Ballif, Christophe

2013-01-01

We describe a nanomoulding technique which allows low-cost nanoscale patterning of functional materials, materials stacks and full devices. Nanomoulding combined with layer transfer enables the replication of arbitrary surface patterns from a master structure onto the functional material. Nanomoulding can be performed on any nanoimprinting setup and can be applied to a wide range of materials and deposition processes. In particular we demonstrate the fabrication of patterned transparent zinc oxide electrodes for light trapping applications in solar cells. PMID:23380874

Hybrid matrix fiber composites

DOEpatents

Deteresa, Steven J.; Lyon, Richard E.; Groves, Scott E.

2003-07-15

Hybrid matrix fiber composites having enhanced compressive performance as well as enhanced stiffness, toughness and durability suitable for compression-critical applications. The methods for producing the fiber composites using matrix hybridization. The hybrid matrix fiber composites include two chemically or physically bonded matrix materials, whereas the first matrix materials are used to impregnate multi-filament fibers formed into ribbons and the second matrix material is placed around and between the fiber ribbons that are impregnated with the first matrix material and both matrix materials are cured and solidified.

[Preparation and characteristics of aerogel-based bioactive materials used in dentistry].

PubMed

Lázár, István; Kuttor, Andrea; Győri, Enikö; Veres, Péter; Fábián, István; Manó, Sándor; Hegedüs, Csaba

2015-03-01

A variety of bioactive materials have been investigated as substitute materials for diseased or damaged bone tissues in dentistry. The aim of this study was to prepare mesoporous silica containing biomaterials by sol-gel technology. These materials may be combinated with hydroxyapatite and β-tricalcium phosphate, as bioactive agents. The synthesis and testing of important physical parameters were performed. Based on these measurements, the silica aerogel can be an applicable material in the dental field in the future.

Impact of morphological changes of LiNi1/3Mn1/3Co1/3O2 on lithium-ion cathode performances

NASA Astrophysics Data System (ADS)

Cabelguen, Pierre-Etienne; Peralta, David; Cugnet, Mikael; Maillet, Pascal

2017-04-01

Major advances in Li-ion battery technology rely on the nanostructuration of active materials to overcome the severe kinetics limitations of new - cheaper and safer - chemistries. However, opening porosities results in the decrease of volumetric performances, closing the door to significant applications such as portable electronics, electromobility, and grid storage. In this study, we analyze the link between morphologies and performances of model LiNi1/3Mn1/3Co1/3O2 materials. By quantifying exhaustively their microstructures using nitrogen adsorption, mercury intrusion porosimetry, and helium pycnometry, we can discuss how porosities and surface areas are linked to the electrochemical behavior. There is no geometrical parameters that can predict the performances of all our materials. The shape of agglomeration dictates the electrochemical behavior. A huge drop in volumetric performances is measured when microstructure is considered. We show that gravimetric and volumetric power performances are contrary to each other. Highly dense materials exhibit, by far, the best power performances in terms of volumetric figures, so that opening porosities might not be the best strategy, even in non-nanosized materials, for Li-ion battery technology.

PyCDT: A Python toolkit for modeling point defects in semiconductors and insulators

DOE PAGES

Broberg, Danny; Medasani, Bharat; Zimmermann, Nils E. R.; ...

2018-02-13

Point defects have a strong impact on the performance of semiconductor and insulator materials used in technological applications, spanning microelectronics to energy conversion and storage. The nature of the dominant defect types, how they vary with processing conditions, and their impact on materials properties are central aspects that determine the performance of a material in a certain application. This information is, however, difficult to access directly from experimental measurements. Consequently, computational methods, based on electronic density functional theory (DFT), have found widespread use in the calculation of point-defect properties. Here we have developed the Python Charged Defect Toolkit (PyCDT) tomore » expedite the setup and post-processing of defect calculations with widely used DFT software. PyCDT has a user-friendly command-line interface and provides a direct interface with the Materials Project database. This allows for setting up many charged defect calculations for any material of interest, as well as post-processing and applying state-of-the-art electrostatic correction terms. Our paper serves as a documentation for PyCDT, and demonstrates its use in an application to the well-studied GaAs compound semiconductor. As a result, we anticipate that the PyCDT code will be useful as a framework for undertaking readily reproducible calculations of charged point-defect properties, and that it will provide a foundation for automated, high-throughput calculations.« less

Integrity of Ceramic Parts Predicted When Loads and Temperatures Fluctuate Over Time

NASA Technical Reports Server (NTRS)

Nemeth, Noel N.

2004-01-01

Brittle materials are being used, and being considered for use, for a wide variety of high performance applications that operate in harsh environments, including static and rotating turbine parts for unmanned aerial vehicles, auxiliary power units, and distributed power generation. Other applications include thermal protection systems, dental prosthetics, fuel cells, oxygen transport membranes, radomes, and microelectromechanical systems (MEMS). In order for these high-technology ceramics to be used successfully for structural applications that push the envelope of materials capabilities, design engineers must consider that brittle materials are designed and analyzed differently than metallic materials. Unlike ductile metals, brittle materials display a stochastic strength response because of the combination of low fracture toughness and the random nature of the size, orientation, and distribution of inherent microscopic flaws. This plus the fact that the strength of a component under load may degrade over time because of slow crack growth means that a probabilistic-based life-prediction methodology must be used when the tradeoffs of failure probability, performance, and useful life are being optimized. The CARES/Life code (which was developed at the NASA Glenn Research Center) predicts the probability of ceramic components failing from spontaneous catastrophic rupture when these components are subjected to multiaxial loading and slow crack growth conditions. Enhancements to CARES/Life now allow for the component survival probability to be calculated when loading and temperature vary over time.

PyCDT: A Python toolkit for modeling point defects in semiconductors and insulators

NASA Astrophysics Data System (ADS)

Broberg, Danny; Medasani, Bharat; Zimmermann, Nils E. R.; Yu, Guodong; Canning, Andrew; Haranczyk, Maciej; Asta, Mark; Hautier, Geoffroy

2018-05-01

Point defects have a strong impact on the performance of semiconductor and insulator materials used in technological applications, spanning microelectronics to energy conversion and storage. The nature of the dominant defect types, how they vary with processing conditions, and their impact on materials properties are central aspects that determine the performance of a material in a certain application. This information is, however, difficult to access directly from experimental measurements. Consequently, computational methods, based on electronic density functional theory (DFT), have found widespread use in the calculation of point-defect properties. Here we have developed the Python Charged Defect Toolkit (PyCDT) to expedite the setup and post-processing of defect calculations with widely used DFT software. PyCDT has a user-friendly command-line interface and provides a direct interface with the Materials Project database. This allows for setting up many charged defect calculations for any material of interest, as well as post-processing and applying state-of-the-art electrostatic correction terms. Our paper serves as a documentation for PyCDT, and demonstrates its use in an application to the well-studied GaAs compound semiconductor. We anticipate that the PyCDT code will be useful as a framework for undertaking readily reproducible calculations of charged point-defect properties, and that it will provide a foundation for automated, high-throughput calculations.

Green synthesis of boron doped graphene and its application as high performance anode material in Li ion battery

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

Sahoo, Madhumita; Sreena, K.P.; Vinayan, B.P.

2015-01-15

Graphical abstract: Boron doped graphene (B-G), synthesized by simple hydrogen induced reduction technique using boric acid as boron precursor, have more uneven surface as a result of smaller bonding distance of boron compared to carbon, showed high capacity and high rate capability compared to pristine graphene as an anode material for Li ion battery application. - Abstract: The present work demonstrates a facile route for the large-scale, catalyst free, and green synthesis approach of boron doped graphene (B-G) and its use as high performance anode material for Li ion battery (LIB) application. Boron atoms were doped into graphene framework withmore » an atomic percentage of 5.93% via hydrogen induced thermal reduction technique using graphite oxide and boric acid as precursors. Various characterization techniques were used to confirm the boron doping in graphene sheets. B-G as anode material shows a discharge capacity of 548 mAh g{sup −1} at 100 mA g{sup −1} after 30th cycles. At high current density value of 1 A g{sup −1}, B-G as anode material enhances the specific capacity by about 1.7 times compared to pristine graphene. The present study shows a simplistic way of boron doping in graphene leading to an enhanced Li ion adsorption due to the change in electronic states.« less

PyCDT: A Python toolkit for modeling point defects in semiconductors and insulators

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

Broberg, Danny; Medasani, Bharat; Zimmermann, Nils E. R.

Point defects have a strong impact on the performance of semiconductor and insulator materials used in technological applications, spanning microelectronics to energy conversion and storage. The nature of the dominant defect types, how they vary with processing conditions, and their impact on materials properties are central aspects that determine the performance of a material in a certain application. This information is, however, difficult to access directly from experimental measurements. Consequently, computational methods, based on electronic density functional theory DFT), have found widespread use in the calculation of point defect properties. Here we have developed the Python Charged Defect Toolkit (PyCDT)more » to expedite the setup and post-processing of defect calculations with widely used DFT software. PyCDT has a user-friendly command-line interface and provides a direct interface with the Materials Project database. This allows for setting up many charged defect calculations for any material of interest, as well as post-processing and applying state-of-the-art electrostatic correction terms. Our paper serves as a documentation for PyCDT, and demonstrates its use in an application to the well-studied GaAs compound semiconductor. We anticipate that the PyCDT code will be useful as a framework for undertaking readily reproducible calculations of charged point-defect properties, and that it will provide a foundation for automated, high-throughput calculations.« less

PyCDT: A Python toolkit for modeling point defects in semiconductors and insulators

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

Broberg, Danny; Medasani, Bharat; Zimmermann, Nils E. R.

Point defects have a strong impact on the performance of semiconductor and insulator materials used in technological applications, spanning microelectronics to energy conversion and storage. The nature of the dominant defect types, how they vary with processing conditions, and their impact on materials properties are central aspects that determine the performance of a material in a certain application. This information is, however, difficult to access directly from experimental measurements. Consequently, computational methods, based on electronic density functional theory (DFT), have found widespread use in the calculation of point-defect properties. Here we have developed the Python Charged Defect Toolkit (PyCDT) tomore » expedite the setup and post-processing of defect calculations with widely used DFT software. PyCDT has a user-friendly command-line interface and provides a direct interface with the Materials Project database. This allows for setting up many charged defect calculations for any material of interest, as well as post-processing and applying state-of-the-art electrostatic correction terms. Our paper serves as a documentation for PyCDT, and demonstrates its use in an application to the well-studied GaAs compound semiconductor. As a result, we anticipate that the PyCDT code will be useful as a framework for undertaking readily reproducible calculations of charged point-defect properties, and that it will provide a foundation for automated, high-throughput calculations.« less

Novel and high-performance asymmetric micro-supercapacitors based on graphene quantum dots and polyaniline nanofibers.

PubMed

Liu, Wenwen; Yan, Xingbin; Chen, Jiangtao; Feng, Yaqiang; Xue, Qunji

2013-07-07

In comparison with graphene sheets, graphene quantum dots (GQDs) exhibit novel chemical/physical properties including nanometer-size, abundant edge defects, good electrical conductivity, high mobility, chemical inertia, stable photoluminescence and better surface grafting, making them promising for fabricating various novel devices. In the present work, an asymmetric micro-supercapacitor, using GQDs as negative active material and polyaniline (PANI) nanofibers as positive active material, is built for the first time by a simple and controllable two-step electro-deposition on interdigital finger gold electrodes. Electrochemical measurements reveal that the as-made GQDs//PANI asymmetric micro-supercapacitor has a more excellent rate capability (up to 1000 V s(-1)) than previously reported electrode materials, as well as faster power response capability (with a very short relaxation time constant of 115.9 μs) and better cycling stability after 1500 cycles in aqueous electrolyte. On this basis, an all-solid-state GQDs//PANI asymmetric micro-supercapacitor is fabricated using H3PO4-polyvinyl alcohol gel as electrolyte, which also exhibits desirable electrochemical capacitive performances. These encouraging results presented here may open up new insight into GQDs with highly promising applications in high-performance energy-storage devices, and further expand the potential applications of GQDs beyond the energy-oriented application of GQDs discussed above.

A Novel Graphene-Polysulfide Anode Material for High-Performance Lithium-Ion Batteries

PubMed Central

Ai, Wei; Xie, Linghai; Du, Zhuzhu; Zeng, Zhiyuan; Liu, Juqing; Zhang, Hua; Huang, Yunhui; Huang, Wei; Yu, Ting

2013-01-01

We report a simple and efficient approach for fabrication of novel graphene-polysulfide (GPS) anode materials, which consists of conducting graphene network and homogeneously distributed polysulfide in between and chemically bonded with graphene sheets. Such unique architecture not only possesses fast electron transport channels, shortens the Li-ion diffusion length but also provides very efficient Li-ion reservoirs. As a consequence, the GPS materials exhibit an ultrahigh reversible capacity, excellent rate capability and superior long-term cycling performance in terms of 1600, 550, 380 mAh g−1 after 500, 1300, 1900 cycles with a rate of 1, 5 and 10 A g−1 respectively. This novel and simple strategy is believed to work broadly for other carbon-based materials. Additionally, the competitive cost and low environment impact may promise such materials and technique a promising future for the development of high-performance energy storage devices for diverse applications. PMID:23903017

Review on recent progress of nanostructured anode materials for Li-ion batteries

NASA Astrophysics Data System (ADS)

Goriparti, Subrahmanyam; Miele, Ermanno; De Angelis, Francesco; Di Fabrizio, Enzo; Proietti Zaccaria, Remo; Capiglia, Claudio

2014-07-01

This review highlights the recent research advances in active nanostructured anode materials for the next generation of Li-ion batteries (LIBs). In fact, in order to address both energy and power demands of secondary LIBs for future energy storage applications, it is required the development of innovative kinds of electrodes. Nanostructured materials based on carbon, metal/semiconductor, metal oxides and metal phosphides/nitrides/sulfides show a variety of admirable properties for LIBs applications such as high surface area, low diffusion distance, high electrical and ionic conductivity. Therefore, nanosized active materials are extremely promising for bridging the gap towards the realization of the next generation of LIBs with high reversible capacities, increased power capability, long cycling stability and free from safety concerns. In this review, anode materials are classified, depending on their electrochemical reaction with lithium, into three groups: intercalation/de-intercalation, alloy/de-alloy and conversion materials. Furthermore, the effect of nanoscale size and morphology on the electrochemical performance is presented. Synthesis of the nanostructures, lithium battery performance and electrode reaction mechanisms are also discussed. To conclude, the main aim of this review is to provide an organic outline of the wide range of recent research progresses and perspectives on nanosized active anode materials for future LIBs.

Élaboration et performances de matériaux supraconducteurs {YBa_2Cu_3O_7} massifs texturés de taille croissante

NASA Astrophysics Data System (ADS)

Chaud, X.; Gautier-Picard, P.; Beaugnon, E.; Porcar, L.; Bourgault, D.; Tournier, R.; Erraud, A.; Tixador, P.

1998-03-01

Industrial applications of the bulk superconducting YBa_2Cu_3O_7 material imply to control the growth of large oriented monodomains in samples of big size (several centimeters). The laboratory EPM-Matformag is committed to produce such materials according to three different methods (zone melting, solidification controlled by a magnetic field, crystal growth from a seed). The results obtained show that it is possible by such methods to elaborate a material with high performances at the centimeter scale and to produce it in series. The availability of such materials allows the measure of physical properties on a large scale and the testing of prototypes for cryo-electrotechnical applications (magnetic bearing, flywheel, coupling device, current lead...). Les applications industrielles des matériaux supraconducteurs massifs YBa_2Cu_3O_7 impliquent de contrôler la croissance de larges monodomaines orientés dans des échantillons de grande taille (plusieurs centimètres). Le laboratoire EPM-Matformag s'est appliqué à produire de tels matériaux selon trois techniques différentes (fusion de zone, solidification contrôlée sous champ magnétique, croissance cristalline à partir d'un germe). Les résultats obtenus montrent qu'il est possible par de telles techniques d'obtenir un matériau performant à l'échelle des centimètres et de le produire en série. La disponibilité de tels matériaux permet de mesurer des propriétés physiques à grande échelle et de tester des prototypes d'applications cryo-électrotechniques (palier magnétique, volant d'inertie, coupleur, amenée de courant, limiteur de courant...).

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

Tan, Lizhen; Yang, Ying; Tyburska-Puschel, Beata

The mission of the Nuclear Energy Enabling Technologies (NEET) program is to develop crosscutting technologies for nuclear energy applications. Advanced structural materials with superior performance at elevated temperatures are always desired for nuclear reactors, which can improve reactor economics, safety margins, and design flexibility. They benefit not only new reactors, including advanced light water reactors (LWRs) and fast reactors such as sodium-cooled fast reactor (SFR) that is primarily designed for management of high-level wastes, but also life extension of the existing fleet when component exchange is needed. Developing and utilizing the modern materials science tools (experimental, theoretical, and computational tools)more » is an important path to more efficient alloy development and process optimization. Ferritic-martensitic (FM) steels are important structural materials for nuclear reactors due to their advantages over other applicable materials like austenitic stainless steels, notably their resistance to void swelling, low thermal expansion coefficients, and higher thermal conductivity. However, traditional FM steels exhibit a noticeable yield strength reduction at elevated temperatures above ~500°C, which limits their applications in advanced nuclear reactors which target operating temperatures at 650°C or higher. Although oxide-dispersion-strengthened (ODS) ferritic steels have shown excellent high-temperature performance, their extremely high cost, limited size and fabricability of products, as well as the great difficulty with welding and joining, have limited or precluded their commercial applications. Zirconium has shown many benefits to Fe-base alloys such as grain refinement, improved phase stability, and reduced radiation-induced segregation. The ultimate goal of this project is, with the aid of computational modeling tools, to accelerate the development of a new generation of Zr-bearing ferritic alloys to be fabricated using conventional steelmaking practices, which have excellent radiation resistance and enhanced high-temperature creep performance greater than Grade 91.« less

Touching the theoretical capacity: synthesizing cubic LiTi2(PO4)3/C nanocomposites for high-performance lithium-ion battery.

PubMed

Deng, Wenjun; Wang, Xusheng; Liu, Chunyi; Li, Chang; Xue, Mianqi; Li, Rui; Pan, Feng

2018-04-05

A cubic LiTi2(PO4)3/C composite is successfully prepared via a simple solvothermal method and further glucose-pyrolysis treatment. The as-fabricated LTP/C material delivers an ultra-high reversible capacity of 144 mA h g-1 at 0.2C rate, which is the highest ever reported, and shows considerable performance improvement compared with before. Combining this with the stable cycling performance and high rate capability, such material has a promising future in practical application.

Perspectives Of Employment Of Pultruded FRP Structural Elements In Seismic Engineering Field

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

Russo, Salvatore; Silvestri, Mirko

2008-07-08

Today the employment of FRP material in structural engineering is in common use, with excellent results in term of applications especially as reinforcement of existing structures. This success is related to the very reduced weight of FRP material, to its performance in term of strength and durability and thanks to the easy use in technical application. There is a modern way to use this material disguised as structural pultruded element (with weight equal to 1600-1800 kg/m{sup 3}) in new constructions, local reinforcements and in other seismic applications. Actually the international technical and scientific literature in form of draft, recommendations andmore » researches on this topic is very rich also taking into account Italian contribution. Some interesting applications of all FRP structures in seismic engineering field are showed in this research in real terms and in form of capability.« less

Flexible devices: from materials, architectures to applications

NASA Astrophysics Data System (ADS)

Zou, Mingzhi; Ma, Yue; Yuan, Xin; Hu, Yi; Liu, Jie; Jin, Zhong

2018-01-01

Flexible devices, such as flexible electronic devices and flexible energy storage devices, have attracted a significant amount of attention in recent years for their potential applications in modern human lives. The development of flexible devices is moving forward rapidly, as the innovation of methods and manufacturing processes has greatly encouraged the research of flexible devices. This review focuses on advanced materials, architecture designs and abundant applications of flexible devices, and discusses the problems and challenges in current situations of flexible devices. We summarize the discovery of novel materials and the design of new architectures for improving the performance of flexible devices. Finally, we introduce the applications of flexible devices as key components in real life. Project supported by the National Key R&D Program of China (Nos. 2017YFA0208200, 2016YFB0700600, 2015CB659300), the National Natural Science Foundation of China (Nos. 21403105, 21573108), and the Fundamental Research Funds for the Central Universities (No. 020514380107).

Overview and major characteristics of future aeronautical and space systems

NASA Technical Reports Server (NTRS)

Venneri, Samuel L.; Noor, Ahmed K.

1992-01-01

A systematic projection is made of prospective materials and structural systems' performance requirements in light of emerging applications. The applications encompass high-speed/long-range rotorcraft, advanced subsonic commercial aircraft, high speed (supersonic) commercial transports, hypersonic aircraft and missiles, extremely high-altitude cruise aircraft and missiles, and aerospace craft and launch vehicles. A tabulation is presented of the materials/structures/dynamics requirements associated with future aerospace systems, as well as the further development needs foreseen in each such case.

PREPARATION AND APPLICATION OF HIGH PERFORMANCE SILICONE RUBBER MIXED MATRIX MEMBRANES FOR ETHANOL-WATER PERVAPORATION

EPA Science Inventory

Polydimethyl siloxane (PDMS) and zeolite incorporated mixed matrix materials are gaining importance in a variety of applications including membrane separation. PDMS based membranes are used in pervaporation (PV), a membrane technology, for the selective removal of organics such ...

Oxygen Transport Membrane Reactors for Oxy-Fuel Combustion and Carbon Capture Purposes

NASA Astrophysics Data System (ADS)

Falkenstein-Smith, Ryan L.

This thesis investigates oxygen transport membrane reactors (OTMs) for the application of oxy-fuel combustion. This is done by evaluating the material properties and oxygen permeability of different OTM compositions subjected to a variety of operating conditions. The scope of this work consists of three components: (1) evaluate the oxygen permeation capabilities of perovskite-type materials for the application of oxy-fuel combustion; (2) determine the effects of dual-phase membrane compositions on the oxygen permeation performance and membrane characteristics; and (3) develop a new method for estimating the oxygen permeation performance of OTMs utilized for the application of oxy-fuel combustion. SrSc0.1Co0.9O3-delta (SSC) is selected as the primary perovskite-type material used in this research due to its reported high ionic and electronic conductive properties and chemical stability. SSC's oxygen ion diffusivity is investigated using a conductivity relaxation technique and thermogravimetric analysis. Material properties such as chemical structure, morphology, and ionic and electronic conductivity are examined by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), and conductivity testing using a four-probe method, respectively. Oxygen permeation tests study the oxygen permeability OTMs under modified membrane temperatures, sweeping gas flow rates, sweeping gas compositions, membrane configurations, and membrane compositions. When utilizing a pure CO2 sweeping gas, the membrane composition was modified with the addition of Sm0.2Ce0.8O1.9-delta (SDC) at varying wt.% to improve the membranes mechanical stability. A newly developed method to evaluate the oxygen permeation performance of OTMs is also presented by fitting OTM's oxygen permeability to the methane fraction in the sweeping gas composition. The fitted data is used to estimate the overall performance and size of OTMs utilized for the application of oxy-fuel combustion. The findings from this research show that under a wide range of membrane temperatures and in a variety of atmospheres, a pure SSC OTM can achieve superior surface exchange and oxygen chemical diffusion coefficients compared to other commonly studied materials. SSC's high oxygen permeability (>1 ml.min -1.cm-2) demonstrates the material's candidacy for the application of oxy-fuel combustion. However, in the presence of rich CO 2 atmospheres, SSC shows mechanical and chemical instabilities due to the carbonate formation on the perovskite structure. The addition of SDC in the membrane composition produces a dual-phase OTM which is observed to improve the oxygen permeation flux when subjected to pure CO2 sweeping gases. When subjected to pure methane sweeping gases, dual-phase OTM compositions exhibits lower oxygen permeability compared to the single-phase SSC OTM. Despite the decline in the oxygen permeation flux, some dual-phase compositions still exhibit a high oxygen permeability, indicating their potential for the application of oxy-fuel combustion. Furthermore, a newly developed method for evaluating OTMs for the application of oxy-fuel combustion is presented in a portion of this work. This new method calculates key components such as the average oxygen permeation flux, approximate effective surface area, and the impact of additional recirculated exhaust into the incoming sweeping gas to provide a detailed understanding of OTM's application for oxy-fuel combustion. The development of this approach will aid in the evaluation of newly developed materials and create a new standard for implementing OTMs for the application of oxy-fuel combustion.

Metamaterials as a Platform for the Development of Novel Materials for Energy Applications. Final Report

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

Padilla, Willie

2016-02-11

Final report detailing the work performed on DESC0005240 at Boston College. Report details research into metamaterial absorber theory, thermophotovoltaics a dynamic 3 state material capable of switching between transmissive, reflective, and absorptive states. Also high temperature NIR metamaterials are explored.

Accelerated long-term assessment of thermal and chemical stability of bio-based phase change materials

USDA-ARS?s Scientific Manuscript database

Thermal energy storage (TES) systems incorporated with phase change materials (PCMs) have potential applications to control energy use by building envelopes. However, it is essential to evaluate long term performance of the PCMs and cost effectiveness prior to full scale implementation. For this rea...

Self-consolidating concrete for prestressed applications - phase II : bridge construction and in-place performance.

DOT National Transportation Integrated Search

2015-04-01

Prior to statewide acceptance of self-consolidating concrete (SCC) in precast, prestressed bridge member : production, the Alabama Department of Transportation sponsored an investigation of the material to be : performed by the Auburn University High...

Self-consolidating concrete for prestressed applications - phase I : girder fabrication and pre-erection performance.

DOT National Transportation Integrated Search

2015-04-01

Prior to statewide acceptance of self-consolidating concrete (SCC) in precast, prestressed bridge member production, the Alabama Department of Transportation sponsored an investigation of the material to be performed by the Auburn University Highway ...

Elastic memory composites (EMC) for deployable industrial and commercial applications

NASA Astrophysics Data System (ADS)

Arzberger, Steven C.; Tupper, Michael L.; Lake, Mark S.; Barrett, Rory; Mallick, Kaushik; Hazelton, Craig; Francis, William; Keller, Phillip N.; Campbell, Douglas; Feucht, Sara; Codell, Dana; Wintergerst, Joe; Adams, Larry; Mallioux, Joe; Denis, Rob; White, Karen; Long, Mark; Munshi, Naseem A.; Gall, Ken

2005-05-01

The use of smart materials and multifunctional components has the potential to provide enhanced performance, improved economics, and reduced safety concerns for applications ranging from outer space to subterranean. Elastic Memory Composite (EMC) materials, based on shape memory polymers and used to produce multifunctional components and structures, are being developed and qualified for commercial use as deployable components and structures. EMC materials are similar to traditional fiber-reinforced composites except for the use of a thermoset shape memory resin that enables much higher packaging strains than traditional composites without damage to the fibers or the resin. This unique capability is being exploited in the development of very efficient EMC structural components for deployable spacecraft systems as well as capability enhancing components for use in other industries. The present paper is intended primarily to describe the transition of EMC materials as smart structure technologies into viable industrial and commercial products. Specifically, the paper discusses: 1) TEMBO EMC materials for deployable space/aerospace systems, 2) TEMBO EMC resins for terrestrial applications, 3) future generation EMC materials.

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.

Process Optimization of Bismaleimide (BMI) Resin Infused Carbon Fiber Composite

NASA Technical Reports Server (NTRS)

Ehrlich, Joshua W.; Tate, LaNetra C.; Cox, Sarah B.; Taylor, Brian J.; Wright, M. Clara; Faughnan, Patrick D.; Batterson, Lawrence M.; Caraccio, Anne J.; Sampson, Jeffery W.

2013-01-01

Engineers today are presented with the opportunity to design and build the next generation of space vehicles out of the lightest, strongest, and most durable materials available. Composites offer excellent structural characteristics and outstanding reliability in many forms that will be utilized in future aerospace applications including the Commercial Crew and Cargo Program and the Orion space capsule. NASA's Composites for Exploration (CoEx) project researches the various methods of manufacturing composite materials of different fiber characteristics while using proven infusion methods of different resin compositions. Development and testing on these different material combinations will provide engineers the opportunity to produce optimal material compounds for multidisciplinary applications. Through the CoEx project, engineers pursue the opportunity to research and develop repair patch procedures for damaged spacecraft. Working in conjunction with Raptor Resins Inc., NASA engineers are utilizing high flow liquid infusion molding practices to manufacture high-temperature composite parts comprised of intermediate modulus 7 (IM7) carbon fiber material. IM7 is a continuous, high-tensile strength composite with outstanding structural qualities such as high shear strength, tensile strength and modulus as well as excellent corrosion, creep, and fatigue resistance. IM7 carbon fiber, combined with existing thermoset and thermoplastic resin systems, can provide improvements in material strength reinforcement and deformation-resistant properties for high-temperature applications. Void analysis of the different layups of the IM7 material discovered the largest total void composition within the [ +45 , 90 , 90 , -45 ] composite panel. Tensile and compressional testing proved the highest mechanical strength was found in the [0 4] layup. This paper further investigates the infusion procedure of a low-cost/high-performance BMI resin into an IM7 carbon fiber material and the optical, chemical, and mechanical analyses performed.

Cryogenic Vacuum Insulation for Vessels and Piping

NASA Technical Reports Server (NTRS)

Kogan, A.; Fesmire, J.; Johnson, W.; Minnick, J.

2010-01-01

Cryogenic vacuum insulation systems, with proper materials selection and execution, can offer the highest levels of thermal performance. Three areas of consideration are vital to achieve the optimum result: materials, representative test conditions, and engineering approach for the particular application. Deficiency in one of these three areas can prevent optimum performance and lead to severe inefficiency. Materials of interest include micro-fiberglass, multilayer insulation, and composite arrangements. Cylindrical liquid nitrogen boil-off calorimetry methods were used. The need for standard thermal conductivity data is addressed through baseline testing. Engineering analysis and design factors such as layer thickness, density, and practicality are also considered.

Automotive applications of chromogenic materials

NASA Astrophysics Data System (ADS)

Lynam, Niall R.

1990-03-01

Automobiles present both opportunities and challenges for large-area chromogenics. Opportunities include optical and thermal control of vehicle glazing along with optical control of rearview mirrors and privacy glass. Challenges include cost-effectively meeting automotive safety, performance, and reliability standards. Worldwide automobile production' for 1987 is listed in Table 1. Of the roughly 33 million cars produced annually, approximately 8% are luxury models which are candidates for features such as auto- matically dimming rearview mirrors or variable opacity sunroofs. Thus copious commercial opportunities await whatever chromogenic technologies qualify for use in automobiles. This review will describe the performance, safety, and reliability/durability required for automotive use. Commercial opportunities and challenges will be discussed including cost factors and specifications. Chromogenic technologies such as electrochromism, liquid crystals and thermochromism will be reviewed in terms of how publicly announced technical developments match automotive needs and expectations. Construction and performance of ex- isting or imminent chromogenic devices will be described. Finally, how opportunities and challenges of the automotive environment translate to other applications for chromogenic materials such as architectural or information display devices will be discussed. The objective is to generally review the applications, the technologies appropriate to these applications, and the automotive chromogenic devices available at the time of writing to match these applications.

Characterization of interdigitated electrode piezoelectric fiber composites under high electrical and mechanical loading

NASA Astrophysics Data System (ADS)

Rodgers, John P.; Bent, Aaron A.; Hagood, Nesbitt W.

1996-05-01

The primary objective of this work is to develop a standard methodology for characterizing structural actuation systems intended for operation in high electrical and mechanical loading environments. The designed set of tests evaluates the performance of the active materials system under realistic operating conditions. The tests are also used to characterize piezoelectric fiber composites which have been developed as an alternative to monolithic piezoceramic wafers for structural actuation applications. The performance of this actuator system has been improved using an interdigitated electrode pattern, which orients the primary component of the electric field into the plane of the structure, enabling the use of the primary piezoelectric effect along the active fibers. One possible application of this technology is in the integral twist actuation of helicopter rotor blades for higher harmonic control. This application requires actuators which can withstand the harsh rotor blade operating environment. This includes large numbers of electrical and mechanical cycles with considerable centripetal and bending loads. The characterization tests include standard active material tests as well as application-driven tests which evaluate the performance of the actuators during simulated operation. Test results for several actuator configurations are provided, including S2 glass- reinforced and E-glass laminated actuators. The study concludes that the interdigitated electrode piezoelectric fiber composite actuator has great potential for high loading applications.

A study of the suitability of ferrite for use in low-field insertion devices

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

Johnson, K.; Hassenzahl, W.V.

1995-02-01

Most insertion devices built to date use rare-earth permanent-magnet materials, which have a high remanent field and are more expensive than many other permanent-magnet materials. Low-field insertion devices could use less-expensive, lower performance magnetic materials if they had suitable magnetic characteristics. These materials must be resistant to demagnetization during construction and operation of the insertion device, have uniform magnetization, possess low minor-axis magnetic moments, and have small minor field components on the surfaces. This paper describes an investigation to determine if ferrite possesses magnetic qualities suitable for insertion device applications. The type of ferrite investigated, MMPA Ceramic 8 from Stackpolemore » Inc., was found to be acceptable for insertion device applications.« less

Crystal Growth of Device Quality Gaas in Space

NASA Technical Reports Server (NTRS)

Gatos, H. C.

1985-01-01

The GaAs research evolves about these key thrust areas. The overall program combines: (1) studies of crystal growth on novel approaches to engineering of semiconductor material (i.e., GaAs and related compounds); (2) investigation and correlation of materials properties and electronic characteristics on a macro- and microscale; and (3) investigation of electronic properties and phenomena controlling device applications and device performance. This effort is aimed at the essential ground-based program which would insure successful experimentation with and eventually processing of GaAs in near zero gravity environment. It is believed that this program addresses in a unique way materials engineering aspects which bear directly on the future exploitation of the potential of GaAs and related materials in device and systems applications.

Development and application of basis database for materials life cycle assessment in china

NASA Astrophysics Data System (ADS)

Li, Xiaoqing; Gong, Xianzheng; Liu, Yu

2017-03-01

As the data intensive method, high quality environmental burden data is an important premise of carrying out materials life cycle assessment (MLCA), and the reliability of data directly influences the reliability of the assessment results and its application performance. Therefore, building Chinese MLCA database is the basic data needs and technical supports for carrying out and improving LCA practice. Firstly, some new progress on database which related to materials life cycle assessment research and development are introduced. Secondly, according to requirement of ISO 14040 series standards, the database framework and main datasets of the materials life cycle assessment are studied. Thirdly, MLCA data platform based on big data is developed. Finally, the future research works were proposed and discussed.

Thermoelectric studies of nanoporous thin films with adjusted pore-edge charges

NASA Astrophysics Data System (ADS)

Hao, Qing; Zhao, Hongbo; Xu, Dongchao

2017-03-01

In recent years, nanoporous thin films have been widely studied for thermoelectric applications. High thermoelectric performance is reported for nanoporous Si films, which is attributed to the dramatically reduced lattice thermal conductivity and bulk-like electrical properties. Porous materials can also be used in gas sensing applications by engineering the surface-trapped charges on pore edges. In this work, an analytical model is developed to explore the relationship between the thermoelectric properties and pore-edge charges in a periodic two-dimensional nanoporous material. The presented model can be widely used to analyze the measured electrical properties of general nanoporous thin films and two-dimensional materials.

Application of electron paramagnetic resonance imaging to the characterization of the Ultem(R) exposed to 1 MeV electrons. Correlation of radical density data to tiger code calculations

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

Suleman, N.K.

1994-12-01

A major long-term goal of the Materials Division at the NASA Langley Research Center is the characterization of new high-performance materials that have potential applications in the aircraft industry, and in space. The materials used for space applications are often subjected to a harsh and potentially damaging radiation environment. The present study constitutes the application of a novel technique to obtain reliable data for ascertaining the molecular basis for the resilience and durability of materials that have been exposed to simulated space radiations. The radiations of greatest concern are energetic electrons and protons, as well as galactic cosmic rays. Presently,more » the effects of such radiation on matter are not understood in their entirety. It is clear however, that electron radiation causes ionization and homolytic bond rupture, resulting in the formation of paramagnetic spin centers in the polymer matrices of the structural materials. Since the detection and structure elucidation of paramagnetic species are most readily accomplished using Electron Paramagnetic Resonance (EPR) Spectroscopy, the NASA LaRC EPR system was brought back on-line during the 1991 ASEE term. The subsequent 1992 ASEE term was devoted to the adaptation of the EPR core system to meet the requirements for EPR Imaging (EPRI), which provides detailed information on the spatial distribution of paramagnetic species in bulk media. The present (1994) ASEE term was devoted to the calibration of this EPR Imaging system, as well as to the application of this technology to study the effects of electron irradiation on Ultem(exp R), a high performance polymer which is a candidate for applications in aerospace. The Ultem was exposed to a dose of 2.4 x 10(exp 9) Rads (1-MeV energy/electron) at the LaRC electron accelerator facility. Subsequently, the exposed specimens were stored in liquid nitrogen, until immediately prior to analyses by EPRI.« less

Energy conversion and storage program

NASA Astrophysics Data System (ADS)

Cairns, E. J.

1992-03-01

The Energy Conversion and Storage Program applies chemistry and materials science principles to solve problems in: (1) production of new synthetic fuels; (2) development of high-performance rechargeable batteries and fuel cells; (3) development of advanced thermochemical processes for energy conversion; (4) characterization of complex chemical processes; and (5) application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, novel materials, and advanced methods of analysis. Electrochemistry research aims to develop advanced power systems for electric vehicle and stationary energy storage applications. Topics include identification of new electrochemical couples for advanced rechargeable batteries, improvements in battery and fuel-cell materials, and the establishment of engineering principles applicable to electrochemical energy storage and conversion. Chemical Applications research includes topics such as separations, catalysis, fuels, and chemical analyses. Included in this program area are projects to develop improved, energy-efficient methods for processing waste streams from synfuel plants and coal gasifiers. Other research projects seek to identify and characterize the constituents of liquid fuel-system streams and to devise energy-efficient means for their separation. Materials Applications research includes the evaluation of the properties of advanced materials, as well as the development of novel preparation techniques. For example, the use of advanced techniques, such as sputtering and laser ablation, are being used to produce high-temperature superconducting films.

Interfacial Engineering of Inorganic Materials for Energy Storage and Conversion Applications

NASA Astrophysics Data System (ADS)

Samiee, Mojtaba

Since the micrometer-sized bulk materials have reached their inherent limits, development of new materials with high performance is essential for low cost and environmentally friendly electrochemical energy storage and conversion devices. One approach is to take advantage of interfacial engineering in order to modify currently developed materials, thus improving their properties for specific applications. The advantage of interfacial engineering is that it can also be applied to newly developed materials to further improve their properties for the specific applications. In first part of this dissertation, a systematic study is performed to investigate the effect of annealing in reducing atmospheres with different oxygen partial pressures and presence of other species (Ar, H2, N2, vacuum or hydrocarbon) on visible-light photocatalytic activity of TiO2. In second part, a facile nitridation method is used to improve the rate capability of TiO 2 as anode material for Li ion batteries. The enhanced high-rate capacities are attributed to moderate surface nitridation with less-disordered nitridated regions, which may enhance the surface electronic conductivity without forming discrete, nanoscale, and surface amorphous films to block the lithium transport. In third part, pseudocapacitive properties of V2O5-based adsorbates supported on TiO2 nanoparticles is systematically measured. Surface amorphous films (SAFs), which form naturally at thermodynamic equilibria at 550-600 °C with self-regulating or "equilibrium" thicknesses on the order of 1 nm, exhibit superior electrochemical performance at moderate and high scan rates (20-500 mV/s) that are of prime importance for supercapacitor applications, as compared with submonolayer and monolayer adsorbates formed at lower equilibration temperatures. In fourth part, we perform a combined experimental and computational investigation into the effects of aliovalent doping in NASICON on both bulk and grain boundary ionic conductivity. Our results show that the dopants with low solid solubility limits in NASICON solid solution lead to the formation of a conducting secondary phase at grain boundaries, thereby improving effective grain boundary conductivity that is otherwise hindered by the poorly-conducting Na3PO4 and ZrO2 secondary phases in undoped NASICON. In fifth part, inline electron holography technique is used to directly observe and investigate the space charge layers at grain boundaries of Y-doped BaZrO3.

High-performance black phosphorus top-gate ferroelectric transistor for nonvolatile memory applications

NASA Astrophysics Data System (ADS)

Lee, Young Tack; Hwang, Do Kyung; Choi, Won Kook

2016-10-01

Two-dimensional (2D) van der Waals (vdW) atomic crystals have been extensively studied and significant progress has been made. The newest 2D vdW material, called black phosphorus (BP), has attracted considerable attention due to its unique physical properties, such as its being a singlecomponent material like graphene, and its having a high mobility and direct band gap. Here, we report on a high-performance BP nanosheet based ferroelectric field effect transistor (FeFET) with a poly(vinylidenefluoride-trifluoroethylene) top-gate insulator for a nonvolatile memory application. The BP FeFETs show the highest linear hole mobility of 563 cm2/Vs and a clear memory window of more than 15 V. For more advanced nonvolatile memory circuit applications, two different types of resistive-load and complementary ferroelectric memory inverters were implemented, which showed distinct memory on/off switching characteristics.

Graphene oxide-based benzimidazole-crosslinked networks for high-performance supercapacitors

NASA Astrophysics Data System (ADS)

Cui, Yi; Cheng, Qian-Yi; Wu, Haiping; Wei, Zhixiang; Han, Bao-Hang

2013-08-01

The synthesis of graphene oxide (GO)-based benzimidazole-crosslinked network (GOBIN) materials is presented. These materials are prepared by the covalent crosslinking of GO sheets using a condensation reaction between the carboxylic acid moieties on the GO surface and the o-aminophenyl end groups of 3,3'-diaminobenzidine (or 1,2,4,5-benzenetetraamine tetrahydrochloride). An efficient one-pot catalyst- and template-free synthesis was performed. The obtained porous GO-based materials possess a Brunauer-Emmett-Teller specific surface area ranging from 260 to 920 m2 g-1. Electrochemical testing indicates that the GOBIN materials display a specific capacitance up to 370 F g-1 at a current density of 0.1 A g-1 and about 90% of the original capacitance is retained after 5000 cycles at a current density of 3 A g-1. Therefore, GOBIN materials can be employed as promising electrode materials for high-performance supercapacitors with outstanding cycling stability. Furthermore, owing to their significantly high specific surface area, these materials also show hydrogen uptake (up to 1.24 wt%, at 77 K and 1.0 bar) and carbon dioxide capture (up to 14.2 wt%, at 273 K and 1.0 bar) properties. As a result, these GO-based porous materials improve both the supercapacitor performance and gas sorption property, which demonstrate an excellent performance in the practical application of energy storage.The synthesis of graphene oxide (GO)-based benzimidazole-crosslinked network (GOBIN) materials is presented. These materials are prepared by the covalent crosslinking of GO sheets using a condensation reaction between the carboxylic acid moieties on the GO surface and the o-aminophenyl end groups of 3,3'-diaminobenzidine (or 1,2,4,5-benzenetetraamine tetrahydrochloride). An efficient one-pot catalyst- and template-free synthesis was performed. The obtained porous GO-based materials possess a Brunauer-Emmett-Teller specific surface area ranging from 260 to 920 m2 g-1. Electrochemical testing indicates that the GOBIN materials display a specific capacitance up to 370 F g-1 at a current density of 0.1 A g-1 and about 90% of the original capacitance is retained after 5000 cycles at a current density of 3 A g-1. Therefore, GOBIN materials can be employed as promising electrode materials for high-performance supercapacitors with outstanding cycling stability. Furthermore, owing to their significantly high specific surface area, these materials also show hydrogen uptake (up to 1.24 wt%, at 77 K and 1.0 bar) and carbon dioxide capture (up to 14.2 wt%, at 273 K and 1.0 bar) properties. As a result, these GO-based porous materials improve both the supercapacitor performance and gas sorption property, which demonstrate an excellent performance in the practical application of energy storage. Electronic supplementary information (ESI) available: Detailed methods of preparation of GOBINPPA, SEM images, IR spectra, TGA, nitrogen adsorption-desorption isotherms, pore size distribution, gravimetric hydrogen adsorption, carbon dioxide adsorption isotherms, and virial analysis of the adsorption data for GOBIN materials. See DOI: 10.1039/c3nr01480k

Overview of NASA Langley's Piezoelectric Ceramic Packaging Technology and Applications

NASA Technical Reports Server (NTRS)

Bryant, Robert G.

2007-01-01

Over the past decade, NASA Langley Research Center (LaRC) has developed several actuator packaging concepts designed to enhance the performance of commercial electroactive ceramics. NASA LaRC focused on properly designed actuator and sensor packaging for the following reasons, increased durability, protect the working material from the environment, allow for proper mechanical and electrical contact, afford "ready to use" mechanisms that are scalable, and develop fabrication methodology applicable to any active material of the same physical class. It is more cost effective to enhance or tailor the performance of existing systems, through innovative packaging, than to develop, test and manufacture new materials. This approach led to the development of several solid state actuators that include THUNDER, the Macrofiber Composite or (MFC) and the Radial Field Diaphragm or (RFD). All these actuators are fabricated using standard materials and processes derived from earlier concepts. NASA s fabrication and packaging technology as yielded, piezoelectric actuators and sensors that are easy to implement, reliable, consistent in properties, and of lower cost to manufacture in quantity, than their predecessors (as evidenced by their continued commercial availability.) These piezoelectric actuators have helped foster new research and development in areas involving computational modeling, actuator specific refinements, and engineering system redesign which led to new applications for piezo-based devices that replace traditional systems currently in use.

Progress on Electronic and Optoelectronic Devices of 2D Layered Semiconducting Materials.

PubMed

Wang, Feng; Wang, Zhenxing; Jiang, Chao; Yin, Lei; Cheng, Ruiqing; Zhan, Xueying; Xu, Kai; Wang, Fengmei; Zhang, Yu; He, Jun

2017-09-01

2D layered semiconducting materials (2DLSMs) represent the thinnest semiconductors, holding many novel properties, such as the absence of surface dangling bonds, sizable band gaps, high flexibility, and ability of artificial assembly. With the prospect of bringing revolutionary opportunities for electronic and optoelectronic applications, 2DLSMs have prospered over the past twelve years. From materials preparation and property exploration to device applications, 2DLSMs have been extensively investigated and have achieved great progress. However, there are still great challenges for high-performance devices. In this review, we provide a brief overview on the recent breakthroughs in device optimization based on 2DLSMs, particularly focussing on three aspects: device configurations, basic properties of channel materials, and heterostructures. The effects from device configurations, i.e., electrical contacts, dielectric layers, channel length, and substrates, are discussed. After that, the affect of the basic properties of 2DLSMs on device performance is summarized, including crystal defects, crystal symmetry, doping, and thickness. Finally, we focus on heterostructures based on 2DLSMs. Through this review, we try to provide a guide to improve electronic and optoelectronic devices of 2DLSMs for achieving practical device applications in the future. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Composite Development and Applications for RLV Tankage

NASA Technical Reports Server (NTRS)

Wright, Richard J.; Achary, David C.; McBain, Michael C.

2003-01-01

The development of polymer composite cryogenic tanks is a critical step in creating the next generation of launch vehicles. Future launch vehicles need to minimize the gross liftoff weight (GLOW), which is possible due to the 28%-41% reduction in weight that composite materials can provide over current aluminum technology. The development of composite cryogenic tanks, feedlines, and unpressurized structures are key enabling technologies for performance and cost enhancements for Reusable Launch Vehicles (RLVs). The technology development of composite tanks has provided direct and applicable data for feedlines, unpressurized structures, material compatibility, and cryogenic fluid containment for highly loaded complex structures and interfaces. All three types of structure have similar material systems, processing parameters, scaling issues, analysis methodologies, NDE development, damage tolerance, and repair scenarios. Composite cryogenic tankage is the most complex of the 3 areas and provides the largest breakthrough in technology. A building block approach has been employed to bring this family of difficult technologies to maturity. This approach has built up composite materials, processes, design, analysis and test methods technology through a series of composite test programs beginning with the NASP program to meet aggressive performance goals for reusable launch vehicles. In this paper, the development and application of advanced composites for RLV use is described.

Evaluation of ceramics for stator application: Gas turbine engine report

NASA Technical Reports Server (NTRS)

Trela, W.; Havstad, P. H.

1978-01-01

Current ceramic materials, component fabrication processes, and reliability prediction capability for ceramic stators in an automotive gas turbine engine environment are assessed. Simulated engine duty cycle testing of stators conducted at temperatures up to 1093 C is discussed. Materials evaluated are SiC and Si3N4 fabricated from two near-net-shape processes: slip casting and injection molding. Stators for durability cycle evaluation and test specimens for material property characterization, and reliability prediction model prepared to predict stator performance in the simulated engine environment are considered. The status and description of the work performed for the reliability prediction modeling, stator fabrication, material property characterization, and ceramic stator evaluation efforts are reported.

Precision measurements of linear scattering density using muon tomography

NASA Astrophysics Data System (ADS)

Åström, E.; Bonomi, G.; Calliari, I.; Calvini, P.; Checchia, P.; Donzella, A.; Faraci, E.; Forsberg, F.; Gonella, F.; Hu, X.; Klinger, J.; Sundqvist Ökvist, L.; Pagano, D.; Rigoni, A.; Ramous, E.; Urbani, M.; Vanini, S.; Zenoni, A.; Zumerle, G.

2016-07-01

We demonstrate that muon tomography can be used to precisely measure the properties of various materials. The materials which have been considered have been extracted from an experimental blast furnace, including carbon (coke) and iron oxides, for which measurements of the linear scattering density relative to the mass density have been performed with an absolute precision of 10%. We report the procedures that are used in order to obtain such precision, and a discussion is presented to address the expected performance of the technique when applied to heavier materials. The results we obtain do not depend on the specific type of material considered and therefore they can be extended to any application.

Advances in aluminum powder usage as an energetic material and applications for rocket propellant

NASA Astrophysics Data System (ADS)

Sadeghipour, S.; Ghaderian, J.; Wahid, M. A.

2012-06-01

Energetic materials have been widely used for military purposes. Continuous research programs are performing in the world for the development of the new materials with higher and improved performance comparing with the available ones in order to fulfill the needs of the military in future. Different sizes of aluminum powders are employed to produce composite rocket propellants with the bases of Ammonium Perchlorate (AP) and Hydroxyl-Terminated-Polybutadiene (HTPB) as oxidizer and binder respectively. This paper concentrates on recent advances in using aluminum as an energetic material and the properties and characteristics pertaining to its combustion. Nano-sized aluminum as one of the most attractable particles in propellants is discussed particularly.

Effects of cryogenic temperature on the mechanical and failure characteristics of melamine-urea-formaldehyde adhesive plywood

NASA Astrophysics Data System (ADS)

Kim, Jeong-Hyeon; Choi, Sung-Woong; Park, Doo-Hwan; Park, Seong-Bo; Kim, Seul-Kee; Park, Kwang-Jun; Lee, Jae-Myung

2018-04-01

The present study investigates the applicability of melamine-urea-formaldehyde (MUF) resin plywood in cryogenic applications, including liquefied natural gas (LNG) carrier insulation systems. Phenolic-formaldehyde (PF) resin plywood has been extensively used as a structural material in industrial applications. However, many shortcomings of PF resin plywood have been reported, and replacement of PF resin plywood with a new material is necessary to resolve these problems. MUF resin plywood has the advantages of short fabrication time, low veneer cost, and economic feasibility compared to PF resin plywood. However, the mechanical and failure characteristics of MUF resin plywood have not yet been investigated at low temperature ranges. For this reason, adapting MUF resin plywood for cryogenic applications has been difficult, despite the many strong points of the material in engineering aspects. In this study, the effects of cryogenic temperature and thermal treatment on the mechanical characteristics of MUF resin plywood are investigated. The performance of MUF resin plywood is compared with that of PF resin plywood to verify the applicability of the material for use as a structural material in LNG insulation systems. The results demonstrate that MUF resin plywood has mechanical properties comparable with those of PF resin plywood, even at cryogenic conditions.

Synthesis and characterization of prospective polyanionic electrode materials for high performance energy storage applications

NASA Astrophysics Data System (ADS)

Jayachandran, M.; Durai, G.; Vijayakumar, T.

2018-04-01

In the present study, Polyanionic compound (SO4)-group based on Li2Ni(SO4)2 (Lithium Nickel Sulphate) composite electrodes materials were prepared by a ball-milling method and solid-state reaction route. X-ray diffraction analysis confirmed the formation of a polycrystalline orthorhombic phase of composite Li2Ni(SO4)2 with an average crystallite size of about 50.16 nm. Field Emission Scanning electron microscopy investigation reveals the spherical shape particles with the particle size of around 200–500 nm. Raman and FTIR analysis confirms the structural and functional groups of the synthesized materials and also the formation of Li2Ni(SO4)2. The electrochemical measurements using cyclic voltammetry (CV) and galvanostatic charging-discharging (GCD) techniques were carried out to study the electrochemical supercapacitive performance of the composite Li2Ni (SO4)2 electrodes. From the CV investigations, an areal capacitance of 508 mF cm‑2 was obtained at 10 mV s‑1. The galvanostatic charge-discharge (GCD) measurements exhibited the areal capacitance of 101 mF cm‑2 at a constant current density of 2 mA cm‑2 in 2 M KOH. These GCD profiles were linear and also symmetric in nature with the maximum columbic efficiency of about 85%. The electrochemical performance of the composite Li2Ni(SO4)2 electrode material shows excellent performance for supercapacitor applications.

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

Yang, Kyoung Mo; Jee, Kye Kwang; Pyo, Chang Ryul

The basis of the leak before break (LBB) concept is to demonstrate that piping will leak significantly before a double ended guillotine break (DEGB) occurs. This is demonstrated by quantifying and evaluating the leak process and prescribing safe shutdown of the plant on the basis of the monitored leak rate. The application of LBB for power plant design has reduced plant cost while improving plant integrity. Several evaluations employing LBB analysis on system piping based on DEGB design have been completed. However, the application of LBB on main steam (MS) piping, which is LBB applicable piping, has not been performedmore » due to several uncertainties associated with occurrence of steam hammer and dynamic strain aging (DSA). The objective of this paper is to demonstrate the applicability of the LBB design concept to main steam lines manufactured with SA106 Gr.C carbon steel. Based on the material properties, including fracture toughness and tensile properties obtained from the comprehensive material tests for base and weld metals, a parametric study was performed as described in this paper. The PICEP code was used to determine leak size crack (LSC) and the FLET code was used to perform the stability assessment of MS piping. The effects of material properties obtained from tests were evaluated to determine the LBB applicability for the MS piping. It can be shown from this parametric study that the MS piping has a high possibility of design using LBB analysis.« less

Editorial

NASA Astrophysics Data System (ADS)

Bruzzi, Mara; Pace, Emanuele; Talamonti, Cinzia

2013-12-01

The 9th edition of the International Conference on Radiation Effects on Semiconductor Materials, Detectors and Devices (RESMDD), held in Florence, at Dipartimento di Fisica ed Astronomia on October 9-12, 2012, was aimed at discussing frontier research activities in several application fields as in nuclear and particle physics, astrophysics, medical and solid-state physics. Main topics discussed in this conference are tracking performance of heavily irradiated silicon detectors, developments required for the luminosity upgrade of the Large Hadron Collider (HL-LHC), radiation effects on semiconductor materials for medical (radiotherapy dosimeters, imaging devices), astrophysics (UV, X- and γ-ray detectors) and environmental applications, microscopic defect analysis of irradiated semiconductor materials and related radiation hardening technologies. On the first day the conference hosted a short course intended to introduce fundamentals in the development of semiconductor detectors for medical applications to graduate and PhD students, post-docs and young researchers, both engineers and physicists. Directors of the School were Prof. Marta Bucciolini of the University of Florence and INFN, Italy and Dr. Carlo Civinini, INFN Firenze, Italy. Emphasis was placed on the underlying physical principles, instrument design, factors affecting performance, and applications in both the clinical and preclinical applications. The School was attended by nearly 40 students/ young researchers. We warmly thank the Directors for organizing this interesting event and the professors and researchers who gave lessons, for sharing their experience and knowledge with the students.

Laser surface texturing of polymers for biomedical applications

NASA Astrophysics Data System (ADS)

Riveiro, Antonio; Maçon, Anthony L. B.; del Val, Jesus; Comesaña, Rafael; Pou, Juan

2018-02-01

Polymers are materials widely used in biomedical science because of their biocompatibility, and good mechanical properties (which, in some cases, are similar to those of human tissues); however, these materials are, in general, chemically and biologically inert. Surface characteristics, such as topography (at the macro-, micro, and nanoscale), surface chemistry, surface energy, charge or wettability are interrelated properties, and they cooperatively influence the biological performance of materials when used for biomedical applications. They regulate the biological response at the implant/tissue interface (e.g., influencing the cell adhesion, cell orientation, cell motility, etc.). Several surface processing techniques have been explored to modulate these properties for biomedical applications. Despite their potentials, these methods have limitations that prevent their applicability. In this regard, laser-based methods, in particular laser surface texturing (LST), can be an interesting alternative. Different works have showed the potentiality of this technique to control the surface properties of biomedical polymers and enhance their biological performance; however, more research is needed to obtain the desired biological response. This work provides a general overview of the basics and applications of LST for the surface modification of polymers currently used in the clinical practice (e.g. PEEK, UHMWPE, PP, etc.). The modification of roughness, wettability, and their impact on the biological response is addressed to offer new insights on the surface modification of biomedical polymers.

Biodegradable Orthopedic Magnesium-Calcium (MgCa) Alloys, Processing, and Corrosion Performance.

PubMed

Salahshoor, Meisam; Guo, Yuebin

2012-01-09

Magnesium-Calcium (Mg-Ca) alloy has received considerable attention as an emerging biodegradable implant material in orthopedic fixation applications. The biodegradable Mg-Ca alloys avoid stress shielding and secondary surgery inherent with permanent metallic implant materials. They also provide sufficient mechanical strength in load carrying applications as opposed to biopolymers. However, the key issue facing a biodegradable Mg-Ca implant is the fast corrosion in the human body environment. The ability to adjust degradation rate of Mg-Ca alloys is critical for the successful development of biodegradable orthopedic implants. This paper focuses on the functions and requirements of bone implants and critical issues of current implant biomaterials. Microstructures and mechanical properties of Mg-Ca alloys, and the unique properties of novel magnesium-calcium implant materials have been reviewed. Various manufacturing techniques to process Mg-Ca based alloys have been analyzed regarding their impacts on implant performance. Corrosion performance of Mg-Ca alloys processed by different manufacturing techniques was compared. In addition, the societal and economical impacts of developing biodegradable orthopedic implants have been emphasized.

Enhanced scintillation of Ba3In(B3O6)3 based on nitrogen doping

NASA Astrophysics Data System (ADS)

Wang, Z. X.; Pei, H.; Tao, X. M.; Cai, G. M.; Mao, R. H.; Jin, Z. P.

2018-02-01

Scintillating materials, as a class of luminescent materials, are highly demanded for practical use in the high-energy detection. However, the applications are often hampered by their low light yield (LY) or long decay time for many traditional scintillators. In this work, upon nitrogen anion doping, scintillation performance in layered borate Ba3In(B3O6)3 (BIB) has been excellently enhanced with high XEL intensity of ～3 times as large as that of commercial Bi4Ge3O12 (BGO) and ultra-fast fluorescent decay time of ～1.25 ns. To shed light on origins of the intrinsic violet-blue emission, we measured the in-situ vacuum ultraviolet excited (VUV) emission spectra of N-BIB ceramic. Combined with experiments and first principles calculations, the band-gap reduction and donor-acceptor density increasing by nitrogen (N) doping is responsible for the enhancement of scintillation performance for N-doped Ba3In(B3O6)3. Moreover, nitrogen anion doping rather than conventional cation doping is found to be also applicable to other intrinsic luminescent materials for enhancing performance.

Carbon Nanotube Self-Gating Diode and Application in Integrated Circuits.

PubMed

Si, Jia; Liu, Lijun; Wang, Fanglin; Zhang, Zhiyong; Peng, Lian-Mao

2016-07-26

A nano self-gating diode (SGD) based on nanoscale semiconducting material is proposed, simulated, and realized on semiconducting carbon nanotubes (CNTs) through a doping-free fabrication process. The relationships between the performance and material/structural parameters of the SGD are explored through numerical simulation and verified by experiment results. Based on these results, performance optimization strategy is outlined, and high performance CNT SGDs are fabricated and demonstrated to surpass other published CNT diodes. In particular the CNT SGD exhibits high rectifier factor of up to 1.4 × 10(6) while retains large on-state current. Benefiting from high yield and stability, CNT SGDs are used for constructing logic and analog integrated circuits. Two kinds of basic digital gates (AND and OR) have been realized on chip through using CNT SGDs and on-chip Ti wire resistances, and a full wave rectifier circuit has been demonstrated through using two CNT SGDs. Although demonstrated here using CNT SGDs, this device structure may in principle be implemented using other semiconducting nanomaterials, to provide ideas and building blocks for electronic applications based on nanoscale materials.

Biodegradable Orthopedic Magnesium-Calcium (MgCa) Alloys, Processing, and Corrosion Performance

PubMed Central

Salahshoor, Meisam; Guo, Yuebin

2012-01-01

Magnesium-Calcium (Mg-Ca) alloy has received considerable attention as an emerging biodegradable implant material in orthopedic fixation applications. The biodegradable Mg-Ca alloys avoid stress shielding and secondary surgery inherent with permanent metallic implant materials. They also provide sufficient mechanical strength in load carrying applications as opposed to biopolymers. However, the key issue facing a biodegradable Mg-Ca implant is the fast corrosion in the human body environment. The ability to adjust degradation rate of Mg-Ca alloys is critical for the successful development of biodegradable orthopedic implants. This paper focuses on the functions and requirements of bone implants and critical issues of current implant biomaterials. Microstructures and mechanical properties of Mg-Ca alloys, and the unique properties of novel magnesium-calcium implant materials have been reviewed. Various manufacturing techniques to process Mg-Ca based alloys have been analyzed regarding their impacts on implant performance. Corrosion performance of Mg-Ca alloys processed by different manufacturing techniques was compared. In addition, the societal and economical impacts of developing biodegradable orthopedic implants have been emphasized. PMID:28817036

Radiation Damage Workshop report. [solar cells

NASA Technical Reports Server (NTRS)

Rahilly, W. P.

1980-01-01

The starting material, cell design/geometry, and cell processing/fabrication for silicon and gallium arsenide solar cells are addressed with reference to radiation damage. In general, it is concluded that diagnostic sensitivities and material purities are basic to making significant gains in end-of-life performance and thermal annealability. Further, GaAs material characterization is so sketchy that a well defined program to evaluate such material for solar cell application is needed to maximize GaAs cell technology benefits.

10 CFR 216.3 - Requests for assistance.

Code of Federal Regulations, 2011 CFR

2011-01-01

... DEPARTMENT OF ENERGY OIL MATERIALS ALLOCATION AND PRIORITY PERFORMANCE UNDER CONTRACTS OR ORDERS TO MAXIMIZE... application are critical and essential for a purpose identified in section 101(c). The application shall be... for which assistance is requested are critical and essential to the construction or operation of the...

10 CFR 216.3 - Requests for assistance.

Code of Federal Regulations, 2012 CFR

2012-01-01

... DEPARTMENT OF ENERGY OIL MATERIALS ALLOCATION AND PRIORITY PERFORMANCE UNDER CONTRACTS OR ORDERS TO MAXIMIZE... application are critical and essential for a purpose identified in section 101(c). The application shall be... for which assistance is requested are critical and essential to the construction or operation of the...

10 CFR 216.3 - Requests for assistance.

Code of Federal Regulations, 2010 CFR

2010-01-01

... DEPARTMENT OF ENERGY OIL MATERIALS ALLOCATION AND PRIORITY PERFORMANCE UNDER CONTRACTS OR ORDERS TO MAXIMIZE... application are critical and essential for a purpose identified in section 101(c). The application shall be... for which assistance is requested are critical and essential to the construction or operation of the...

Microstructural Properties of Cement Paste and Mortar Modified by Low Cost Nanoplatelets Sourced from Natural Materials.

PubMed

Huang, Piao; Lv, Liming; Liao, Wei; Lu, Chunhua; Xu, Zhongzi

2018-05-11

Nanomaterials have been widely used in cement-based materials. Graphene has excellent properties for improving the durability of cement-based materials. Given its high production budget, it has limited its wide potential for application in the field of engineering. Hence, it is very meaningful to obtain low cost nanoplatelets from natural materials that can replace graphene nanoplatelets (GNPs) The purpose of this paper is to improve the resistance to chloride ion penetration by optimizing the pore structure of cement-based materials, and another point is to reduce investment costs. The results illustrated that low cost CaCO₃ nanoplatelets (CCNPs) were successfully obtained under alkali treatment of seashell powder, and the chloride ion permeability of cement-based materials significantly decreased by 15.7% compared to that of the control samples when CCNPs were incorporated. Furthermore, the compressive strength of cement pastes at the age of 28 days increased by 37.9% than that of the plain sample. Improvement of performance of cement-based materials can be partly attributed to the refinement of the pore structure. In addition, AFM was employed to characterize the nanoplatelet thickness of CCNPs and the pore structures of the cement-based composites were analyzed by MIP, respectively. CCNPs composite cement best performance could lay the foundation for further study of the durability of cement-based materials and the application of decontaminated seashells.

Microstructural Properties of Cement Paste and Mortar Modified by Low Cost Nanoplatelets Sourced from Natural Materials

PubMed Central

Lv, Liming; Liao, Wei; Lu, Chunhua; Xu, Zhongzi

2018-01-01

Nanomaterials have been widely used in cement-based materials. Graphene has excellent properties for improving the durability of cement-based materials. Given its high production budget, it has limited its wide potential for application in the field of engineering. Hence, it is very meaningful to obtain low cost nanoplatelets from natural materials that can replace graphene nanoplatelets (GNPs) The purpose of this paper is to improve the resistance to chloride ion penetration by optimizing the pore structure of cement-based materials, and another point is to reduce investment costs. The results illustrated that low cost CaCO3 nanoplatelets (CCNPs) were successfully obtained under alkali treatment of seashell powder, and the chloride ion permeability of cement-based materials significantly decreased by 15.7% compared to that of the control samples when CCNPs were incorporated. Furthermore, the compressive strength of cement pastes at the age of 28 days increased by 37.9% than that of the plain sample. Improvement of performance of cement-based materials can be partly attributed to the refinement of the pore structure. In addition, AFM was employed to characterize the nanoplatelet thickness of CCNPs and the pore structures of the cement-based composites were analyzed by MIP, respectively. CCNPs composite cement best performance could lay the foundation for further study of the durability of cement-based materials and the application of decontaminated seashells. PMID:29751666

TheraCal LC: From Biochemical and Bioactive Properties to Clinical Applications

PubMed Central

Rabi, Tarek

2018-01-01

Background Direct pulp capping is a popular treatment modality among dentists. TheraCal LC is a calcium silicate-based material that is designed as a direct/indirect pulp capping material. The material might be very attractive for clinicians because of its ease of handling. Unlike other calcium silicate-based materials, TheraCal LC is resin-based and does not require any conditioning of the dentine surface. The material can be bonded with different types of adhesives directly after application. There has been considerable research performed on this material since its launching; however, there are no review articles that collates information and data obtained from these studies. This review discusses the various characteristics of the material with the aim of establishing a better understanding for its clinical use. Methods A search was conducted using search engines (PubMed and Cochrane databases) in addition to reference mining of the articles that was used to locate other papers. The process of searching for the relevant studies was performed using the keywords pulp protection, pulp capping, TheraCal, and calcium silicates. Only articles in English published in peer-reviewed journals were included in the review. Conclusion This review underlines the fact that further in vitro and in vivo studies are required before TheraCal LC can be used as a direct pulp capping material. PMID:29785184

Thermal interface material characterization for cryogenic electronic packaging solutions

NASA Astrophysics Data System (ADS)

Dillon, A.; McCusker, K.; Van Dyke, J.; Isler, B.; Christiansen, M.

2017-12-01

As applications of superconducting logic technologies continue to grow, the need for efficient and reliable cryogenic packaging becomes crucial to development and testing. A trade study of materials was done to develop a practical understanding of the properties of interface materials around 4 K. While literature exists for varying interface tests, discrepancies are found in the reported performance of different materials and in the ranges of applied force in which they are optimal. In considering applications extending from top cooling a silicon chip to clamping a heat sink, a range of forces from approximately 44 N to approximately 445 N was chosen for testing different interface materials. For each range of forces a single material was identified to optimize the thermal conductance of the joint. Of the tested interfaces, indium foil clamped at approximately 445 N showed the highest thermal conductance. Results are presented from these characterizations and useful methodologies for efficient testing are defined.

Nanostructured Materials Utilized in Biopolymer-based Plastics for Food Packaging Applications.

PubMed

Ghanbarzadeh, Babak; Oleyaei, Seyed Amir; Almasi, Hadi

2015-01-01

Most materials currently used for food packaging are nondegradable, generating environmental problems. Several biopolymers have been exploited to develop materials for ecofriendly food packaging. However, the use of biopolymers has been limited because of their usually poor mechanical and barrier properties, which may be improved by adding reinforcing compounds (fillers), forming composites. Most reinforced materials present poor matrix-filler interactions, which tend to improve with decreasing filler dimensions. The use of fillers with at least one nanoscale dimension (nanoparticles) produces nanocomposites. Nanoparticles have proportionally larger surface area than their microscale counterparts, which favors the filler-matrix interactions and the performance of the resulting material. Besides nanoreinforcements, nanoparticles can have other functions when added to a polymer, such as antimicrobial activity, etc. in this review paper, the structure and properties of main kinds of nanostructured materials which have been studied to use as nanofiller in biopolymer matrices are overviewed, as well as their effects and applications.

Scaled-Up Production and Transport Applications of Graphitic Carbon Nanomaterials

NASA Astrophysics Data System (ADS)

Saviers, Kimberly R.

Graphitic carbon nanomaterials enhance the performance of engineered systems for energy harvesting and storage. However, commercial availability remains largely cost-prohibitive due to technical barriers to mass production. This thesis examines both the scaled-up production and energy transport applications of graphitic materials. Cost driven-production of graphitic petals is developed, carbon nanotube array thermal interface materials enhance waste heat energy harvesting, and microsupercapacitors are visually examined using a new electroreflectance measurement method. Graphitic materials have previously been synthesized using batch-style processing methods with small sample sizes, limiting their commercial viability. In order to increase production throughput, a roll-to-roll radio-frequency plasma chemical vapor deposition method is employed to continuously deposit graphitic petals on carbon fiber tow. In consideration of a full production framework, efficient and informative characterization methods in the form of electrical resistance and electrochemical capacitance are highlighted. To co-optimize the functional characteristics of the material, the processing conditions are comprehensively varied using a data-driven predictive design of experiments method. Repeatable and reliable production of graphitic materials will enable a host of creative graphene-based devices to emerge into the marketplace. Two such applications are discussed in the remaining chapters. Waste heat is most efficiently harvested at high temperatures, such as vehicle exhaust systems near 600°C. However, the resistance to heat flux at the interfaces between the harvesting device and its surroundings is detrimental to the system-level performance. To study the performance of thermal interface materials up to 700°C, a reference bar measurement method was designed. Design considerations are discussed and compared to past implementations, particularly regarding radiation heat flux and thermal expansion at these elevated temperatures. The microscale roughness of the contacting measurement surface is fully characterized, as it fundamentally affects the resulting thermal interface resistance. This comprehensive method for determining thermal interface resistance at high temperatures includes the physical equipment, data acquisition system, and data analysis method. Thermomechanical evaluation of carbon nanotube arrays up to 700°C has shown that the arrays provide mechanical flexibility to accommodate thermal expansion in a thermomechanically mismatched interface. To demonstrate the application of the arrays for improving energy generation, they were evaluated in conjunction with a thermoelectric module. The system-level efficiency increases significantly when a carbon nanotube array is applied to the hot side of the thermoelectric module. Additional materials characterization suggests the presence of a strong thermal connection between the carbon nanotubes and their catalyst layers, due to covalent bonding between them. In another application of harvesting waste heat, the carbon nanotube arrays increase the performance of a thermo-magnetically actuated shuttle device for solar photovoltaic cells due to decreased thermal interface resistance. Vertically-oriented graphitic petals have previously enhanced supercapacitor power density. Here, a spatiotemporal characterization method is developed and utilized to study ageing phenomena in microsupercapacitor electrodes. The electroreflectance method captures images of charge accumulation in the electrodes at varying states during each charge-discharge cycle. The method was exploited by imaging each an ideal device and a device with defects over an extended period of over four million cycles. The charge accumulation patterns over the ageing period relate to the physical transport behavior. During a single discharge cycle, one may visually observe the electrons drifting out of the electrode. Overall, the investigations herein determine the following. Continuous production of graphitic petals is possible and is optimized by considering the effect of plasma conditions on the resulting functional performance of the material. Thermal interface resistance may be measured at high temperatures in order to understand the viability of interface materials for energy harvesting applications. Carbon nanotube array thermal interface materials lead to increased energy generation from thermoelectric modules. Spatial electroreflectance measurements of microsupercapacitors lead to observation of decreased physical wetting between the electrode and electrolyte, impacting device performance. Looking forward, creative application of graphitic carbon nanomaterials, coupled with cost-driven production capability, will launch them into the commercial marketplace.

Thermoelectric Performance Enhancement by Surrounding Crystalline Semiconductors with Metallic Nanoparticles

NASA Technical Reports Server (NTRS)

Kim, Hyun-Jung; King, Glen C.; Park, Yeonjoon; Lee, Kunik; Choi, Sang H.

2011-01-01

Direct conversion of thermal energy to electricity by thermoelectric (TE) devices may play a key role in future energy production and utilization. However, relatively poor performance of current TE materials has slowed development of new energy conversion applications. Recent reports have shown that the dimensionless Figure of Merit, ZT, for TE devices can be increased beyond the state-of-the-art level by nanoscale structuring of materials to reduce their thermal conductivity. New morphologically designed TE materials have been fabricated at the NASA Langley Research Center, and their characterization is underway. These newly designed materials are based on semiconductor crystal grains whose surfaces are surrounded by metallic nanoparticles. The nanoscale particles are used to tailor the thermal and electrical conduction properties for TE applications by altering the phonon and electron transport pathways. A sample of bismuth telluride decorated with metallic nanoparticles showed less thermal conductivity and twice the electrical conductivity at room temperature as compared to pure Bi2Te3. Apparently, electrons cross easily between semiconductor crystal grains via the intervening metallic nanoparticle bridges, but phonons are scattered at the interfacing gaps. Hence, if the interfacing gap is larger than the mean free path of the phonon, thermal energy transmission from one grain to others is reduced. Here we describe the design and analysis of these new materials that offer substantial improvements in thermoelectric performance.

Development of high-performance concrete mixtures for durable bridge decks in Montana using locally available materials.

DOT National Transportation Integrated Search

2005-03-01

"The Montana Department of Transportation (MDT) is performing research to develop a cost-effective, indigenous highperformance : concrete (HPC) for use in bridge deck applications. The investigation was divided into two tasks: 1) : identification of ...

Design and evaluation of a single-span bridge using ultra-high performance concrete.

DOT National Transportation Integrated Search

2009-09-01

"Research presented herein describes an application of a newly developed material called Ultra-High Performance Concrete (UHPC) to a : single-span bridge. The two primary objectives of this research were to develop a shear design procedure for possib...

Design and evaluation of a single-span bridge using ultra-high performance concrete.

DOT National Transportation Integrated Search

2009-09-01

Research presented herein describes an application of a newly developed material called Ultra-High Performance Concrete (UHPC) to a : single-span bridge. The two primary objectives of this research were to develop a shear design procedure for possibl...

Determination of Tasks Required by Graduates of Manufacturing Engineering Technology Programs.

ERIC Educational Resources Information Center

Zirbel, Jay H.

1993-01-01

A Delphi panel of 14 experts identified 37 tasks performed by/qualities needed by manufacturing engineering technologists. Most important were work ethic, performance quality, communication skills, teamwork, computer applications, manufacturing basics, materials knowledge, troubleshooting, supervision, and global issues. (SK)

Development, characterization and applications of a non proprietary ultra high performance concrete for highway bridges : final report.

DOT National Transportation Integrated Search

2016-03-14

Ultra-high performance concrete (UHPC) is a new class of cementitious materials that have : exceptional mechanical and durability characteristics. UHPC is commercially available. : However, its cost for construction of highway structures is prohibiti...

MnO2 prepared by hydrothermal method and electrochemical performance as anode for lithium-ion battery

PubMed Central

2014-01-01

Two α-MnO2 crystals with caddice-clew-like and urchin-like morphologies are prepared by the hydrothermal method, and their structure and electrochemical performance are characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), galvanostatic cell cycling, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS). The morphology of the MnO2 prepared under acidic condition is urchin-like, while the one prepared under neutral condition is caddice-clew-like. The identical crystalline phase of MnO2 crystals is essential to evaluate the relationship between electrochemical performances and morphologies for lithium-ion battery application. In this study, urchin-like α-MnO2 crystals with compact structure have better electrochemical performance due to the higher specific capacity and lower impedance. We find that the relationship between electrochemical performance and morphology is different when MnO2 material used as electrochemical supercapacitor or as anode of lithium-ion battery. For lithium-ion battery application, urchin-like MnO2 material has better electrochemical performance. PMID:24982603

Chemical hydrogen storage material property guidelines for automotive applications

NASA Astrophysics Data System (ADS)

Semelsberger, Troy A.; Brooks, Kriston P.

2015-04-01

Chemical hydrogen storage is the sought after hydrogen storage media for automotive applications because of the expected low pressure operation (<20 atm), moderate temperature operation (<200 °C), system gravimetric capacities (>0.05 kg H2/kgsystem), and system volumetric capacities (>0.05 kg H2/Lsystem). Currently, the primary shortcomings of chemical hydrogen storage are regeneration efficiency, fuel cost and fuel phase (i.e., solid or slurry phase). Understanding the required material properties to meet the DOE Technical Targets for Onboard Hydrogen Storage Systems is a critical knowledge gap in the hydrogen storage research community. This study presents a set of fluid-phase chemical hydrogen storage material property guidelines for automotive applications meeting the 2017 DOE technical targets. Viable material properties were determined using a boiler-plate automotive system design. The fluid-phase chemical hydrogen storage media considered in this study were neat liquids, solutions, and non-settling homogeneous slurries. Material properties examined include kinetics, heats of reaction, fuel-cell impurities, gravimetric and volumetric hydrogen storage capacities, and regeneration efficiency. The material properties, although not exhaustive, are an essential first step in identifying viable chemical hydrogen storage material properties-and most important, their implications on system mass, system volume and system performance.

In vitro comparison of implant- versus gingiva-supported removable dentures in anterior and posterior applications.

PubMed

Rosentritt, Martin; Heidtkamp, Felix; Hösl, Helmut; Hahnel, Sebastian; Preis, Verena

2016-03-01

Removable dentures with different denture teeth may provide different performance and resistance in implant and gingival situations, or anterior and posterior applications. Two situations of removable dentures were investigated: gingiva (flexible) and implant (rigid) bearing. For simulating the gingiva/jaw situation, the dentures were supported with flexible lining material. For the implant situation, implants (d = 4.1 mm) were screwed into polymethylenmethacrylate (PMMA) resin. Two commercial (Vita-Physiodens MRP, SR Vivodent/Orthotyp DCL) and two experimental materials (EXP1, EXP2) were investigated in anterior (A) and posterior (P) tooth locations. Chewing simulation was performed, and failures were analyzed (microscopy, SEM). Fracture strength of surviving dentures was determined. Only EXP1 revealed failures during chewing simulation. Failures varied between anterior and posterior locations, and between implant (P:4x; A:7x) or gingiva (P:1x; A:2x) situations. Kaplan-Meier log-rank test revealed significant differences for implant situations (p < 0.002), but not for gingiva bearing (p > 0.093). Fracture testing in the implant situation provided significantly highest values for EXP2 (1476.4 ± 532.2 N) in posterior location, and for DCL (1575.4 ± 264.4 N) and EXP2 (1797.0 ± 604.2 N) in anterior location. For gingival bearing, significantly highest values were found for DCL/P (2148.3 ± 836.3 N), and significantly lowest results for EXP1/A (308.2 ± 115.6 N). For EXP1 + EXP2 + Vita/P and for EXP1/A no significant differences were found between implant- or gingiva-supported situations. Anterior and posterior teeth showed different material-dependent in vitro performance, further influenced by implant/gingiva bearing. While an implant in anterior application increased fracture strength of two materials, it decreased fracture values of 3/4 of the materials in posterior application. Survival of denture teeth may be influenced by material, oral position, and bearing situation.

Iron-Based Amorphous Metals: High-Performance Corrosion-Resistant Material Development

NASA Astrophysics Data System (ADS)

Farmer, Joseph; Choi, Jor-Shan; Saw, Cheng; Haslam, Jeffrey; Day, Dan; Hailey, Phillip; Lian, Tiangan; Rebak, Raul; Perepezko, John; Payer, Joe; Branagan, Daniel; Beardsley, Brad; D'Amato, Andy; Aprigliano, Lou

2009-06-01

An overview of the High-Performance Corrosion-Resistant Materials (HPCRM) Program, which was cosponsored by the Defense Advanced Research Projects Agency (DARPA) Defense Sciences Office (DSO) and the U.S. Department of Energy (DOE) Office of Civilian and Radioactive Waste Management (OCRWM), is discussed. Programmatic investigations have included a broad range of topics: alloy design and composition, materials synthesis, thermal stability, corrosion resistance, environmental cracking, mechanical properties, damage tolerance, radiation effects, and important potential applications. Amorphous alloys identified as SAM2X5 (Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4) and SAM1651 (Fe48Mo14Cr15Y2C15B6) have been produced as meltspun ribbons (MSRs), dropcast ingots, and thermal-spray coatings. Chromium (Cr), molybdenum (Mo), and tungsten (W) additions provided corrosion resistance, while boron (B) enabled glass formation. Earlier electrochemical studies of MSRs and ingots of these amorphous alloys demonstrated outstanding passive film stability. More recently, thermal-spray coatings of these amorphous alloys have been made and subjected to long-term salt-fog and immersion tests; good corrosion resistance has been observed during salt-fog testing. Corrosion rates were measured in situ with linear polarization, while the open-circuit corrosion potentials (OCPs) were simultaneously monitored; reasonably good performance was observed. The sensitivity of these measurements to electrolyte composition and temperature was determined. The high boron content of this particular amorphous metal makes this amorphous alloy an effective neutron absorber and suitable for criticality-control applications. In general, the corrosion resistance of such iron-based amorphous metals is maintained at operating temperatures up to the glass transition temperature. These materials are much harder than conventional stainless steel and Ni-based materials, and are proving to have excellent wear properties, sufficient to warrant their use in earth excavation, drilling, and tunnel-boring applications. Large areas have been successfully coated with these materials, with thicknesses of approximately 1 cm. The observed corrosion resistance may enable applications of importance in industries such as oil and gas production, refining, nuclear power generation, shipping, etc.

Synthesis of biomass derived carbon materials for environmental engineering and energy storage applications

NASA Astrophysics Data System (ADS)

Huggins, Mitchell Tyler

Biomass derived carbon (BC) can serve as an environmentally and cost effective material for both remediation and energy production/storage applications. The use of locally derived biomass, such as unrefined wood waste, provides a renewable feedstock for carbon material production compared to conventional unrenewable resources like coal. Additionally, energy and capital cost can be reduced through the reduction in transport and processing steps and the use of spent material as a soil amendment. However, little work has been done to evaluate and compare biochar to conventional materials such as granular activated carbon or graphite in advanced applications of Environmental Engineering. In this work I evaluated the synthesis and compared the performance of biochar for different applications in wastewater treatment, nutrient recovery, and energy production and storage. This includes the use of biochar as an electrode and filter media in several bioelectrochemical systems (BES) treating synthetic and industrial wastewater. I also compared the treatment efficiency of granular biochar as a packed bed adsorbent for the primary treatment of high strength brewery wastewater. My studies conclude with the cultivation of fungal biomass to serve as a template for biochar synthesis, controlling the chemical and physical features of the feedstock and avoiding some of the limitations of waste derived materials.

Integrated Application of Quality-by-Design Principles to Drug Product Development: A Case Study of Brivanib Alaninate Film-Coated Tablets.

PubMed

Badawy, Sherif I F; Narang, Ajit S; LaMarche, Keirnan R; Subramanian, Ganeshkumar A; Varia, Sailesh A; Lin, Judy; Stevens, Tim; Shah, Pankaj A

2016-01-01

Modern drug product development is expected to follow quality-by-design (QbD) paradigm. At the same time, although there are several issue-specific examples in the literature that demonstrate the application of QbD principles, a holistic demonstration of the application of QbD principles to drug product development and control strategy, is lacking. This article provides an integrated case study on the systematic application of QbD to product development and demonstrates the implementation of QbD concepts in the different aspects of product and process design for brivanib alaninate film-coated tablets. Using a risk-based approach, the strategy for development entailed identification of product critical quality attributes (CQAs), assessment of risks to the CQAs, and performing experiments to understand and mitigate identified risks. Quality risk assessments and design of experiments were performed to understand the quality of the input raw materials required for a robust formulation and the impact of manufacturing process parameters on CQAs. In addition to the material property and process parameter controls, the proposed control strategy includes use of process analytical technology and conventional analytical tests to control in-process material attributes and ensure quality of the final product. Copyright © 2016. Published by Elsevier Inc.

Engineering design of a high-temperature superconductor current lead

NASA Astrophysics Data System (ADS)

Niemann, R. C.; Cha, Y. S.; Hull, J. R.; Daugherty, M. A.; Buckles, W. E.

As part of the US Department of Energy's Superconductivity Pilot Center Program, Argonne National Laboratory and Superconductivity, Inc., are developing high-temperature superconductor (HTS) current leads suitable for application to superconducting magnetic energy storage systems. The principal objective of the development program is to design, construct, and evaluate the performance of HTS current leads suitable for near-term applications. Supporting objectives are to (1) develop performance criteria; (2) develop a detailed design; (3) analyze performance; (4) gain manufacturing experience in the areas of materials and components procurement, fabrication and assembly, quality assurance, and cost; (5) measure performance of critical components and the overall assembly; (6) identify design uncertainties and develop a program for their study; and (7) develop application-acceptance criteria.

Selective Plasma Etching of Polymeric Substrates for Advanced Applications

PubMed Central

Puliyalil, Harinarayanan; Cvelbar, Uroš

2016-01-01

In today’s nanoworld, there is a strong need to manipulate and process materials on an atom-by-atom scale with new tools such as reactive plasma, which in some states enables high selectivity of interaction between plasma species and materials. These interactions first involve preferential interactions with precise bonds in materials and later cause etching. This typically occurs based on material stability, which leads to preferential etching of one material over other. This process is especially interesting for polymeric substrates with increasing complexity and a “zoo” of bonds, which are used in numerous applications. In this comprehensive summary, we encompass the complete selective etching of polymers and polymer matrix micro-/nanocomposites with plasma and unravel the mechanisms behind the scenes, which ultimately leads to the enhancement of surface properties and device performance. PMID:28335238

Silicon Carbide Monofilament Reinforced Titanium Composites For Space Structures: A New Material Option

NASA Astrophysics Data System (ADS)

Kyle-Henney, Stephen; Flitcroft, Stephen; Shatwell, Robert; Gibbon, David; Voss, Gary; Harkness, Patrick

2012-07-01

Silicon carbide fibre reinforced titanium composite material has been in development since the 1980s initially for high temperature structures on hypersonic vehicles (HOTOL, NASP). Since then development has focused on military and civil aircraft. Development in the European Union has reached a level of maturity where it is again being considered for space applications. Current activities include pressure vessels and studies for launch vehicles and satellite applications. The paper provides background to the technology key performance characteristics current application work and future activities. The renewed interest in hypersonic vehicles has also picked up on the potential for lightweight metallic composites.

Aerogel Use as a Skin Protective Liner In Space Suits and Prosthetic Limbs Project

NASA Technical Reports Server (NTRS)

Roberson, Luke Bennett

2014-01-01

Existing materials for prosthetic liners tend to be thick and airtight, causing perspiration to accumulate inside the liner and potentially causing infection and injury. The purpose of this project was to examine the suitability of aerogel for prosthetic liner applications for use in space suits and orthopedics. Three tests were performed on several types of aerogel to assess the properties of each material, and our initial findings demonstrated that these materrials would be excellent candidates for liner applications for prosthetics and space suits. The project is currently on hold until additional funding is obtained for application testing at the VH Hospitals in Tampa

Surface and interface sciences of Li-ion batteries. -Research progress in electrode-electrolyte interface-

NASA Astrophysics Data System (ADS)

Minato, Taketoshi; Abe, Takeshi

2017-12-01

The application potential of Li-ion batteries is growing as demand increases in different fields at various stages in energy systems, in addition to their conventional role as power sources for portable devices. In particular, applications in electric vehicles and renewable energy storage are increasing for Li-ion batteries. For these applications, improvements in battery performance are necessary. The Li-ion battery produces and stores electric power from the electrochemical redox reactions between the electrode materials. The interface between the electrodes and electrolyte strongly affects the battery performance because the charge transfer causing the electrode redox reaction begins at this interface. Understanding of the surface structure, electronic structure, and chemical reactions at the electrode-electrolyte interface is necessary to improve battery performance. However, the interface is located between the electrode and electrolyte materials, hindering the experimental analysis of the interface; thus, the physical properties and chemical processes have remained poorly understood until recently. Investigations of the physical properties and chemical processes at the interface have been performed using advanced surface science techniques. In this review, current knowledge and future research prospects regarding the electrode-electrolyte interface are described for the further development of Li-ion batteries.

Aerogel Insulation Systems for Space Launch Applications

NASA Technical Reports Server (NTRS)

Fesmire, James E.

2005-01-01

New developments in materials science in the areas of solution gelation processes and nanotechnology have led to the recent commercial production of aerogels. Concurrent with these advancements has been the development of new approaches to cryogenic thermal insulation systems. For example, thermal and physical characterizations of aerogel beads under cryogenic-vacuum conditions have been performed at the Cryogenics Test Laboratory of the NASA Kennedy Space Center. Aerogel-based insulation system demonstrations have also been conducted to improve performance for space launch applications. Subscale cryopumping experiments show the thermal insulating ability of these fully breathable nanoporous materials. For a properly executed thermal insulation system, these breathable aerogel systems are shown to not cryopump beyond the initial cooldown and thermal stabilization phase. New applications are being developed to augment the thermal protection systems of space launch vehicles, including the Space Shuttle External Tank. These applications include a cold-boundary temperature of 90 K with an ambient air environment in which both weather and flight aerodynamics are important considerations. Another application is a nitrogen-purged environment with a cold-boundary temperature of 20 K where both initial cooldown and launch ascent profiles must be considered. Experimental results and considerations for these flight system applications are discussed.

Improved Damage Resistant Composite Materials Incorporating Shape Memory Alloys

NASA Technical Reports Server (NTRS)

Paine, Jeffrey S. N.; Rogers, Craig A.

1996-01-01

Metallic shape memory alloys (SMA) such as nitinol have unique shape recovery behavior and mechanical properties associated with a material phase change that have been used in a variety of sensing and actuation applications. Recent studies have shown that integrating nitinol-SMA actuators into composite materials increases the composite material's functionality. Hybrid composites of conventional graphite/epoxy or glass/epoxy and nitinol-SMA elements can perform functions in applications where monolithic composites perform inadequately. One such application is the use of hybrid composites to function both in load bearing and armor capacities. While monolithic composites with high strength-to-weight ratios function efficiently as loadbearing structures, because of their brittle nature, impact loading can cause significant catastrophic damage. Initial composite failure modes such as delamination and matrix cracking dissipate some impact energy, but when stress exceeds the composite's ultimate strength, fiber fracture and material perforation become dominant. One of the few methods that has been developed to reduce material perforation is hybridizing polymer matrix composites with tough kevlar or high modulus polyethynylene plies. The tough fibers increase the impact resistance and the stiffer and stronger graphite fibers carry the majority of the load. Similarly, by adding nitinol-SMA elements that absorb impact energy through the stress-induced martensitic phase transformation, the composites' impact perforation resistance can be greatly enhanced. The results of drop-weight and high velocity gas-gun impact testing of various composite materials will be presented. The results demonstrate that hybridizing composites with nitinol-SMA elements significantly increases perforation resistance compared to other traditional toughening elements. Inspection of the composite specimens at various stages of perforation by optical microscope illustrates the mechanisms by which perforation is initiated. Results suggest that the out-of-plane transverse shear properties of the composite and nitinol elements have a significant effect on the perforation resistance. Applications that can utilize the hybrid composites effectively will also be presented with the experimental studies.

Highly Active 2D Layered MoS 2 -rGO Hybrids for Energy Conversion and Storage Applications.

PubMed

Kamila, Swagatika; Mohanty, Bishnupad; Samantara, Aneeya K; Guha, Puspendu; Ghosh, Arnab; Jena, Bijayalaxmi; Satyam, Parlapalli V; Mishra, B K; Jena, Bikash Kumar

2017-08-21

The development of efficient materials for the generation and storage of renewable energy is now an urgent task for future energy demand. In this report, molybdenum disulphide hollow sphere (MoS 2 -HS) and its reduced graphene oxide hybrid (rGO/MoS 2 -S) have been synthesized and explored for energy generation and storage applications. The surface morphology, crystallinity and elemental composition of the as-synthesized materials have been thoroughly analysed. Inspired by the fascinating morphology of the MoS 2 -HS and rGO/MoS 2 -S materials, the electrochemical performance towards hydrogen evolution and supercapacitor has been demonstrated. The rGO/MoS 2 -S shows enhanced gravimetric capacitance values (318 ± 14 Fg -1 ) with higher specific energy/power outputs (44.1 ± 2.1 Whkg -1 and 159.16 ± 7.0 Wkg -1 ) and better cyclic performances (82 ± 0.95% even after 5000 cycles). Further, a prototype of the supercapacitor in a coin cell configuration has been fabricated and demonstrated towards powering a LED. The unique balance of exposed edge site and electrical conductivity of rGO/MoS 2 -S shows remarkably superior HER performances with lower onset over potential (0.16 ± 0.05 V), lower Tafel slope (75 ± 4 mVdec -1 ), higher exchange current density (0.072 ± 0.023 mAcm -2 ) and higher TOF (1.47 ± 0.085 s -1 ) values. The dual performance of the rGO/MoS 2 -S substantiates the promising application for hydrogen generation and supercapacitor application of interest.

Nickel cobalt oxide nanowire-reduced graphite oxide composite material and its application for high performance supercapacitor electrode material.

PubMed

Wang, Xu; Yan, Chaoyi; Sumboja, Afriyanti; Lee, Pooi See

2014-09-01

In this paper, we report a facile synthesis method of mesoporous nickel cobalt oxide (NiCo2O4) nanowire-reduced graphite oxide (rGO) composite material by urea induced hydrolysis reaction, followed by sintering at 300 degrees C. P123 was used to stabilize the GO during synthesis, which resulted in a uniform coating of NiCo2O4 nanowire on rGO sheet. The growth mechanism of the composite material is discussed in detail. The NiCo2O4-rGO composite material showed an outstanding electrochemical performance of 873 F g(-1) at 0.5 A g(-1) and 512 F g(-1) at 40 A g(-1). This method provides a promising approach towards low cost and large scale production of supercapacitor electrode material.

Performance of selected polymeric materials on LDEF

NASA Technical Reports Server (NTRS)

Young, Philip R.; Slemp, Wayne S.; Stein, Bland A.

1993-01-01

The NASA Long Duration Exposure Facility (LDEF) provided a unique environmental exposure of a wide variety of materials for potential advanced spacecraft application. This paper examines the molecular level response of selected polymeric materials which flew onboard this vehicle. Polymers include epolyimide, polysulfone, and polystyrene film and polyimide, polysulfone, and epoxy matrix resin/graphite fiber reinforced composites. Several promising experimental films were also studied. Most specimens received 5.8 years of low Earth orbital (LEO) exposure on LDEF. Several samples received on 10 months of exposure. Chemical characterization techniques included ultraviolet-visible and infrared spectroscopy, thermal analysis, x-ray photoelectron spectroscopy, and selected solution property measurements. Results suggest that many molecular level effects present during the first 10 months of exposure were not present after 5.8 years of exposure for specimens on or near Row 9. Increased AO fluence near the end of the mission likely eroded away much environmentally induced surface phenomena. The objective of this work is to provide fundamental information for use in improving the performance of polymeric materials for LEO application. A secondary objective is to gain an appreciation for the constraints and limitations of results from LDEF polymeric materials experiments.

Size effect in thermoelectric materials

NASA Astrophysics Data System (ADS)

Mao, Jun; Liu, Zihang; Ren, Zhifeng

2016-12-01

Thermoelectric applications have attracted increasing interest recently due to its capability of converting waste heat into electricity without hazardous emissions. Materials with enhanced thermoelectric performance have been reported in recent two decades. The revival of research for thermoelectric materials began in early 1990s when the size effect is considered. Low-dimensional materials with exceptionally high thermoelectric figure of merit (ZT) have been presented, which broke the limit of ZT around unity. The idea of size effect in thermoelectric materials even inspired the later nanostructuring and band engineering strategies, which effectively enhanced the thermoelectric performance of bulk materials. In this overview, the size effect in low-dimensional thermoelectric materials is reviewed. We first discuss the quantum confinement effect on carriers, including the enhancement of electronic density of states, semimetal to semiconductor transition and carrier pocket engineering. Then, the effect of assumptions on theoretical calculations is presented. Finally, the effect of phonon confinement and interface scattering on lattice thermal conductivity is discussed.

Advances in thermoelectric materials research: Looking back and moving forward.

PubMed

He, Jian; Tritt, Terry M

2017-09-29

High-performance thermoelectric materials lie at the heart of thermoelectrics, the simplest technology applicable to direct thermal-to-electrical energy conversion. In its recent 60-year history, the field of thermoelectric materials research has stalled several times, but each time it was rejuvenated by new paradigms. This article reviews several potentially paradigm-changing mechanisms enabled by defects, size effects, critical phenomena, anharmonicity, and the spin degree of freedom. These mechanisms decouple the otherwise adversely interdependent physical quantities toward higher material performance. We also briefly discuss a number of promising materials, advanced material synthesis and preparation techniques, and new opportunities. The renewable energy landscape will be reshaped if the current trend in thermoelectric materials research is sustained into the foreseeable future. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Application of ionic liquid for extraction and separation of bioactive compounds from plants.

PubMed

Tang, Baokun; Bi, Wentao; Tian, Minglei; Row, Kyung Ho

2012-09-01

In recent years, ionic liquids (ILs), as green and designer solvents, have accelerated research in analytical chemistry. This review highlights some of the unique properties of ILs and provides an overview of the preparation and application of IL or IL-based materials to extract bioactive compounds in plants. IL or IL-based materials in conjunction with liquid-liquid extraction (LLE), ultrasonic-assisted extraction (UAE), microwave-assisted extraction (MAE), high performance liquid chromatography (HPLC) and solid-phase extraction (SPE) analytical technologies etc., have been applied successfully to the extraction or separation of bioactive compounds from plants. This paper reviews the available data and references to examine the advantages of IL and IL-based materials in these applications. In addition, the main target compounds reviewed in this paper are bioactive compounds with multiple therapeutic effects and pharmacological activities. Based on the importance of the targets, this paper reviews the applications of ILs, IL-based materials or co-working with analytical technologies. The exploitation of new applications of ILs on the extraction of bioactive compounds from plant samples is expected to increase. Copyright © 2012 Elsevier B.V. All rights reserved.

Multi-band filter design with less total film thickness for short-wave infrared

NASA Astrophysics Data System (ADS)

Yan, Yung-Jhe; Chien, I.-Pen; Chen, Po-Han; Chen, Sheng-Hui; Tsai, Yi-Chun; Ou-Yang, Mang

2017-08-01

A multi-band pass filter array was proposed and designed for short wave infrared applications. The central wavelength of the multi-band pass filters are located about 905 nm, 950 nm, 1055 nm and 1550 nm. In the simulation of an optical interference band pass filter, high spectrum performance (high transmittance ratio between the pass band and stop band) relies on (1) the index gap between the selected high/low-index film materials, with a larger gap correlated to higher performance, and (2) sufficient repeated periods of high/low-index thin-film layers. When determining high and low refractive index materials, spectrum performance was improved by increasing repeated periods. Consequently, the total film thickness increases rapidly. In some cases, a thick total film thickness is difficult to process in practice, especially when incorporating photolithography liftoff. Actually the maximal thickness of the photoresist being able to liftoff will bound the total film thickness of the band pass filter. For the application of the short wave infrared with the wavelength range from 900nm to 1700nm, silicone was chosen as a high refractive index material. Different from other dielectric materials used in the visible range, silicone has a higher absorptance in the visible range opposite to higher transmission in the short wave infrared. In other words, designing band pass filters based on silicone as a high refractive index material film could not obtain a better spectrum performance than conventional high index materials like TiO2 or Ta2O5, but also its material cost would reduce about half compared to the total film thickness with the conventional material TiO2. Through the simulation and several experimental trials, the total film thickness below 4 um was practicable and reasonable. The fabrication of the filters was employed a dual electric gun deposition system with ion assisted deposition after the lithography process. Repeating four times of lithography and deposition process and black matrix coating, the optical device processes were completed.

Separator Materials Used in Secondary Alkaline Batteries Characterized and Evaluated

NASA Technical Reports Server (NTRS)

1996-01-01

Nickel-cadmium (Ni/Cd) and nickel-hydrogen (Ni/H2) secondary alkaline batteries are vital to aerospace applications. Battery performance and cycle life are significantly affected by the type of separators used in those batteries. A team from NASA Lewis Research Center's Electrochemical Technology Branch developed standardized testing procedures to characterize and evaluate new and existing separator materials to improve performance and cycle life of secondary alkaline batteries. Battery separators must function as good electronic insulators and as efficient electrolyte reservoirs. At present, new types of organic and inorganic separator materials are being developed for Ni/Cd and Ni/H2 batteries. The separator material previously used in the NASA standard Ni/Cd was Pellon 2505, a 100-percent nylon-6 polymer that must be treated with zinc chloride (ZnCl2) to bond the fibers. Because of stricter Environmental Protection Agency regulation of ZnCl2 emissions, the battery community has been searching for new separators to replace Pellon 2505. As of today, two candidate separator materials have been identified; however, neither of the two materials have performed as well as Pellon 2505. The separator test procedures that were devised at Lewis are being implemented to expedite the search for new battery separators. The new test procedures, which are being carried out in the Separator Laboratory at Lewis, have been designed to guarantee accurate evaluations of the properties that are critical for sustaining proper battery operation. These properties include physical and chemical stability, chemical purity, gas permeability, electrolyte retention and distribution, uniformity, porosity, and area resistivity. A manual containing a detailed description of 12 separator test procedures has been drafted and will be used by the battery community to evaluate candidate separator materials for specific applications. These standardized procedures will allow for consistent, uniform, and reliable results that will ensure that separator materials have the desired properties for long life and good performance in secondary alkaline cells.

Geotextiles : a specific application of biofibers

Treesearch

B. W. English

1995-01-01

Geotextiles are any textile like material used to enhance soil structural performance. Biobased geotextiles are used for short term (6 months to 10 year) applications where biodegradability is a positive attribute, such as mulching and erosion control. Fiber options for biobased geotextiles include cereal straws, coir, jute, kenaf, flax, sisal, hemp, cotton, woodfiber...

Carbonaceous electrode materials for supercapacitors.

PubMed

Hao, Long; Li, Xianglong; Zhi, Linjie

2013-07-26

Supercapacitors have been widely studied around the world in recent years, due to their excellent power density and long cycle life. As the most frequently used electrode materials for supercapacitors, carbonaceous materials attract more and more attention. However, their relatively low energy density still holds back the widespread application. Up to now, various strategies have been developed to figure out this problem. This research news summarizes the recent advances in improving the supercapacitor performance of carbonaceous materials, including the incorporation of heteroatoms and the pore size effect (subnanopores' contribution). In addition, a new class of carbonaceous materials, porous organic networks (PONs) has been managed into the supercapacitor field, which promises great potential in not only improving the supercapacitor performances, but also unraveling the related mechanisms. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An Assessment of Recycled Refractory Material Performance After Two Years of Service in a Carbon Bake Furnace

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

Schubert, N.; Bennett, J.P.; Kwong, K.S.

1999-10-27

Material removed from carbon bake furnaces used to manufacture anodes for the production of aluminum metal has historically been disposed by landfill. This material is composed primarily of 50% alumina refractory. in 1997, Alcoa completed a highly successful program to reuse the spent refractories in castables for carbon bake furnace headwalls and flooring, as roadbed aggregate, and in other internal applications. This program recycled/reused 11,000 metric tons of used refractory material (99% of the material removed from the carbon bake furnace) and saved Alcoa over 3.8 of the 9.6 million dollar projected furnace rebuild costs. As assessment is made ofmore » the performance of the recycled refractory components after two years of service.« less

Green and biodegradable composite films with novel antimicrobial performance based on cellulose.

PubMed

Wu, Yuehan; Luo, Xiaogang; Li, Wei; Song, Rong; Li, Jing; Li, Yan; Li, Bin; Liu, Shilin

2016-04-15

In order to obtain a safe and biodegradable material with antimicrobial properties from cellulose for food packaging, we presented a facile way to graft chitosan onto the oxidized cellulose films. The obtained films had a high transparent property of above 80% transmittance, excellent barrier properties against oxygen and antimicrobial properties against Escherichia coli and Staphylococcus aureus. The antimicrobial properties, mechanical properties, and water vapor permeability of composites are essential characteristics in determining their applicability as food-packaging materials. Moreover, using a sausage model, it was shown that the composites exhibited better performance than traditional polyethylene packaging material and demonstrated good potential as food packaging materials. The results presented a new insight into the development of green materials for food packaging. Copyright © 2015 Elsevier Ltd. All rights reserved.

Structural Polymer-Based Carbon Nanotube Composite Fibers: Understanding the Processing–Structure–Performance Relationship

PubMed Central

Song, Kenan; Zhang, Yiying; Meng, Jiangsha; Green, Emily C.; Tajaddod, Navid; Li, Heng; Minus, Marilyn L.

2013-01-01

Among the many potential applications of carbon nanotubes (CNT), its usage to strengthen polymers has been paid considerable attention due to the exceptional stiffness, excellent strength, and the low density of CNT. This has provided numerous opportunities for the invention of new material systems for applications requiring high strength and high modulus. Precise control over processing factors, including preserving intact CNT structure, uniform dispersion of CNT within the polymer matrix, effective filler–matrix interfacial interactions, and alignment/orientation of polymer chains/CNT, contribute to the composite fibers’ superior properties. For this reason, fabrication methods play an important role in determining the composite fibers’ microstructure and ultimate mechanical behavior. The current state-of-the-art polymer/CNT high-performance composite fibers, especially in regards to processing–structure–performance, are reviewed in this contribution. Future needs for material by design approaches for processing these nano-composite systems are also discussed. PMID:28809290

A study of the effect of sonication time on the catalytic performance of layered WS2 from various sources.

PubMed

Leong, Shi Xuan; Mayorga-Martinez, Carmen C; Sofer, Zdeněk; Luxa, Jan; Tan, Shu Min; Pumera, Martin

2017-01-25

WS 2 is a transition metal dichalcogenide (TMD) with many potential applications from catalysis to sensing, and is of interest both in its bulk and monolayer forms. There is discrepancy in the literature on the reported electrocatalytic effect of layered WS 2 . In this study, we examine two issues: the influence of the WS 2 source and the effect of a common agitation technique via ultrasonication on the observed electrocatalysis. Bulk WS 2 from five different chemical providers demonstrated different HER electrocatalytic performances. Changes to the duration of sonication result in different HER electrocatalytic performances across all WS 2 materials. This may affect the efficiency of subsequent modifications from which these TMD materials serve as precursor materials. On the other hand, while WS 2 materials from different suppliers showed varying HET performances, changes in sonication time have no significant effect on their HET performances. Both the WS 2 source and the duration of sonication have different implications for the electrochemical performance of bulk WS 2 and thus represent important variables to consider in research involving WS 2 .

40 CFR 65.160 - Performance test and TRE index value determination records.

Code of Federal Regulations, 2010 CFR

2010-07-01

... concentration of TOC or regulated material is determined. (1) Nonflare combustion device. Where an owner or... TOC achieved by the incinerator determined as specified in § 65.158(b)(4), as applicable, or the concentration of regulated material or TOC (parts per million by volume, by compound) determined as specified in...

Guidance for Performing Tests on Dredged Material Proposed for Ocean Disposal at the Historic Area Remediation Site

EPA Pesticide Factsheets

Guidance presents the sediment testing guidelines and requirements to be used by applicants who wish to obtain a Department of the Army permit from the USACE-New York District for dredging and placement of dredged material at the HARS in the Atlantic Ocean

Finite Element Analysis of Morphing Piezoelectric Structures Studied

NASA Technical Reports Server (NTRS)

Lee, Ho-Jun

2002-01-01

The development of morphing aerospace structures that optimize their shape offers the potential to significantly improve the performance of existing airplanes. These morphing vehicles will operate with new capabilities to reduce noise, damp vibrations, manipulate flow, and monitor damage. Piezoelectric materials represent one of the popular materials currently being investigated for applications in morphing structures.

Swollen hexagonal liquid crystals as smart nanoreactors: implementation in materials chemistry for energy applications.

PubMed

Ghosh, Srabanti; Ramos, Laurence; Remita, Hynd

2018-03-29

Materials are the key roadblocks for the commercialization of energy conversion devices in fuel cells and solar cells. Significant research has focused on tuning the intrinsic properties of materials at the nanometer scale. The soft template mediated controlled fabrication of advanced nanostructured materials is attracting considerable interest due to the promising applications of these materials in catalysis and electrocatalysis. Swollen hexagonal lyotropic liquid crystals (SLCs) consist of oil-swollen surfactant-stabilized 1D, 2D or 3D nanometric assemblies regularly arranged in an aqueous solvent. Interestingly, the characteristic size of the SLCs can be controlled by adjusting the volume ratio of oil to water. The non-polar and/or polar compartments of the SLCs can be doped with guest molecules and used as nanoreactors for the synthesis of various metals (Pt, Pd, Au, etc.), conducting polymers and composite nanostructures with controlled size and shape. 1D, 2D and 3D mono- and bimetallic nanostructures of controlled composition and porosity can also be fabricated. These materials have demonstrated impressive enhancements of their electrochemical properties as compared to their bulk counterparts and have been identified as promising for further implementation in energy harvesting applications. In this review article, recent research materials are described regarding the development of functional materials with much improved performances for catalysis applications. This review addresses a brief overview of swollen hexagonal mesophases as nanoreactors, describes examples of nanostructured materials synthesized in these nanoreactors, shows several examples of the energy conversion applications in solar light harvesting, fuel cells etc. and also summarizes the associated reaction mechanisms developed in the recent literature for enhanced catalytic activity.

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

Lee, Young-Ho; Byun, Thak Sang

Accident-tolerant fuels are expected to have considerably longer coping time to respond to the loss of active cooling under severe accidents and, at the same time, have comparable or improved fuel performance during normal operation. The wear resistance of accident tolerant fuels, therefore, needs to be examined to determine the applicability of these cladding candidates to the current operating PWRs because the most common failure of nuclear fuel claddings is still caused by grid-to-rod fretting during normal operations. In this study, reciprocating sliding wear tests on three kinds of cladding candidates for accident-tolerant fuels have been performed to investigate themore » tribological compatibilities of selfmated cladding candidates and to determine the direct applicability of conventional Zirconium-based alloys as supporting structural materials. The friction coefficients of the cladding candidates are strongly influenced by the test environments and coupled materials. The wear test results under water lubrication conditions indicate that the supporting structural materials for the cladding candidates of accident-tolerant fuels need to be replaced with the same cladding materials instead of using conventional Zirconium-based alloys.« less

A High‐Voltage and High‐Capacity Li1+xNi0.5Mn1.5O4 Cathode Material: From Synthesis to Full Lithium‐Ion Cells

PubMed Central

Mancini, Marilena; Gabrielli, Giulio; Kinyanjui, Michael; Kaiser, Ute; Wohlfahrt‐Mehrens, Margret

2016-01-01

Abstract We report Co‐free, Li‐rich Li1+xNi0.5Mn1.5O4 (0

The comparison between gallium arsenide and indium gallium arsenide as materials for solar cell performance using Silvaco application

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

Zahari, Suhaila Mohd; Norizan, Mohd Natashah; Mohamad, Ili Salwani

2015-05-15

The work presented in this paper is about the development of single and multilayer solar cells using GaAs and InGaAs in AM1.5 condition. The study includes the modeling structure and simulation of the device using Silvaco applications. The performance in term of efficiency of Indium Gallium Arsenide (InGaAs) and GaAs material was studied by modification of the doping concentration and thickness of material in solar cells. The efficiency of the GaAs solar cell was higher than InGaAs solar cell for single layer solar cell. Single layer GaAs achieved an efficiency about 25% compared to InGaAs which is only 2.65% ofmore » efficiency. For multilayer which includes both GaAs and InGaAs, the output power, P{sub max} was 8.91nW/cm² with the efficiency only 8.51%. GaAs is one of the best materials to be used in solar cell as a based compared to InGaAs.« less

Improved performance of organic solar cells with solution processed hole transport layer

NASA Astrophysics Data System (ADS)

Bhargav, Ranoo; Gairola, S. P.; Patra, Asit; Naqvi, Samya; Dhawan, S. K.

2018-06-01

This work is based on Cobalt Oxide as solution processed, inexpensive and effective hole transport layer (HTL) for efficient organic photovoltaic applications (OPVs). In Organic solar cell (OSC) devices ITO coated glass substrate used as a transparent anode electrode for light incident, HTL material Co3O4 dissolve in DMF solvent deposited on anode electrode, after that active layer material (donor/acceptor) deposited on to HTL and finally Al were deposited by thermal evaporation used as cathode electrode. These devices were fabricated with PCDTBT well known low band gap donor material in OSCs and blended with PC71BM as an acceptor material using simplest device structure ITO/Co3O4/active layer/Al at ambient conditions. The power conversion efficiencies (PCEs) based on Co3O4 and PEDOT:PSS have been achieved to up to 3.21% and 1.47% with PCDTBT respectively. In this study we reported that the devices fabricated with Co3O4 showed better performance as compare to the devices fabricated with well known and most studied solution processed HTL material PEDOT:PSS under identical environmental conditions. The surface morphology of the HTL film was characterized by (AFM). Lastly, we have provided Co3O4 as an efficient hole transport material HTL for solution processed organic photovoltaic applications.

Sol-gel derived electrode materials for supercapacitor applications

NASA Astrophysics Data System (ADS)

Lin, Chuan

1998-12-01

Electrochemical capacitors have been receiving increasing interest in recent years for use in energy storage systems because of their high energy and power density and long cycle lifes. Possible applications of electrochemical capacitors include high power pulsed lasers, hybrid power system for electric vehicles, etc. In this dissertation, the preparation of electrode materials for use as electrochemical capacitors has been studied using the sol-gel process. The high surface area electrode materials explored in this work include a synthetic carbon xerogel for use in a double-layer capacitor, a cobalt oxide xerogel for use in a pseudocapacitor, and a carbon-ruthenium xerogel composite, which utilizes both double-layer and faradaic capacitances. The preparation conditions of these materials were investigated in detail to maximize the surface area and optimize the pore size so that more energy could be stored while minimizing mass transfer limitations. The microstructures of the materials were also correlated with their performance as electrochemical capacitors to improve their energy and power densities. Finally, an idealistic mathematical model, including both double-layer and faradaic processes, was developed and solved numerically. This model can be used to perform the parametric studies of an electrochemical capacitor so as to gain a better understanding of how the capacitor works and also how to improve cell operations and electrode materials design.

Graphene oxide-based benzimidazole-crosslinked networks for high-performance supercapacitors.

PubMed

Cui, Yi; Cheng, Qian-Yi; Wu, Haiping; Wei, Zhixiang; Han, Bao-Hang

2013-09-21

The synthesis of graphene oxide (GO)-based benzimidazole-crosslinked network (GOBIN) materials is presented. These materials are prepared by the covalent crosslinking of GO sheets using a condensation reaction between the carboxylic acid moieties on the GO surface and the o-aminophenyl end groups of 3,3'-diaminobenzidine (or 1,2,4,5-benzenetetraamine tetrahydrochloride). An efficient one-pot catalyst- and template-free synthesis was performed. The obtained porous GO-based materials possess a Brunauer-Emmett-Teller specific surface area ranging from 260 to 920 m(2) g(-1). Electrochemical testing indicates that the GOBIN materials display a specific capacitance up to 370 F g(-1) at a current density of 0.1 A g(-1) and about 90% of the original capacitance is retained after 5000 cycles at a current density of 3 A g(-1). Therefore, GOBIN materials can be employed as promising electrode materials for high-performance supercapacitors with outstanding cycling stability. Furthermore, owing to their significantly high specific surface area, these materials also show hydrogen uptake (up to 1.24 wt%, at 77 K and 1.0 bar) and carbon dioxide capture (up to 14.2 wt%, at 273 K and 1.0 bar) properties. As a result, these GO-based porous materials improve both the supercapacitor performance and gas sorption property, which demonstrate an excellent performance in the practical application of energy storage.

High performance large infrared and visible astronomy arrays for low background applications: instruments performance data and future developments at Raytheon

NASA Astrophysics Data System (ADS)

Beuville, Eric; Acton, David; Corrales, Elizabeth; Drab, John; Levy, Alan; Merrill, Michael; Peralta, Richard; Ritchie, William

2007-09-01

Raytheon Vision Systems (RVS) has developed a family of high performance large format infrared detector arrays for astronomy and civil space applications. RVS offers unique off-the-shelf solutions to the astronomy community. This paper describes mega-pixel arrays, based on multiple detector materials, developed for astronomy and low-background applications. New focal plane arrays under development at RVS for the astronomy community will also be presented. Large Sensor Chip Assemblies (SCAs) using various detector materials like Si:PIN, HgCdTe, InSb, and Si:As IBC, covering a detection range from visible to large wavelength infrared (LWIR) have been demonstrated with an excellent quantum efficiency and very good uniformity. These focal plane arrays have been assembled using state-of-the-art low noise, low power, readout integrated circuits (ROIC) designed at RVS. Raytheon packaging capabilities address reliability, precision alignment and flatness requirements for both ground-based and space applications. Multiple SCAs can be packaged into even larger focal planes. The VISTA telescope, for example, contains sixteen 2k × 2k infrared focal plane arrays. RVS astronomical arrays are being deployed world-wide in ground-based and space-based applications. A summary of performance data for each of these array types from instruments in operation will be presented (VIRGO Array for large format SWIR, the ORION and VISTA Arrays, NEWFIRM and other solutions for MWIR spectral ranges).

Materials insights into low-temperature performances of lithium-ion batteries

NASA Astrophysics Data System (ADS)

Zhu, Gaolong; Wen, Kechun; Lv, Weiqiang; Zhou, Xingzhi; Liang, Yachun; Yang, Fei; Chen, Zhilin; Zou, Minda; Li, Jinchao; Zhang, Yuqian; He, Weidong

2015-12-01

Lithium-ion batteries (LIBs) have been employed in many fields including cell phones, laptop computers, electric vehicles (EVs) and stationary energy storage wells due to their high energy density and pronounced recharge ability. However, energy and power capabilities of LIBs decrease sharply at low operation temperatures. In particular, the charge process becomes extremely sluggish at temperatures below -20 °C, which severely limits the applications of LIBs in some cold areas during winter. Extensive research has shown that the electrolyte/electrode composition and microstructure are of fundamental importance to low-temperature performances of LIBs. In this report, we review the recent findings in the role of electrolytes, anodes, and cathodes in the low temperature performances of LIBs. Our overview aims to understand comprehensively the fundamental origin of low-temperature performances of LIBs from a materials perspective and facilitates the development of high-performance lithium-ion battery materials that are operational at a large range of working temperatures.

Hydroxylapatite nanoparticles: fabrication methods and medical applications

NASA Astrophysics Data System (ADS)

Okada, Masahiro; Furuzono, Tsutomu

2012-12-01

Hydroxylapatite (or hydroxyapatite, HAp) exhibits excellent biocompatibility with various kinds of cells and tissues, making it an ideal candidate for tissue engineering, orthopedic and dental applications. Nanosized materials offer improved performances compared with conventional materials due to their large surface-to-volume ratios. This review summarizes existing knowledge and recent progress in fabrication methods of nanosized (or nanostructured) HAp particles, as well as their recent applications in medical and dental fields. In section 1, we provide a brief overview of HAp and nanoparticles. In section 2, fabrication methods of HAp nanoparticles are described based on the particle formation mechanisms. Recent applications of HAp nanoparticles are summarized in section 3. The future perspectives in this active research area are given in section 4.

Precision and resolution in laser direct microstructuring with bursts of picosecond pulses

NASA Astrophysics Data System (ADS)

Mur, Jaka; Petkovšek, Rok

2018-01-01

Pulsed laser sources facilitate various applications, including efficient material removal in different scientific and industrial applications. Commercially available laser systems in the field typically use a focused laser beam of 10-20 μm in diameter. In line with the ongoing trends of miniaturization, we have developed a picosecond fiber laser-based system combining fast beam deflection and tight focusing for material processing and optical applications. We have predicted and verified the system's precision, resolution, and minimum achievable feature size for material processing applications. The analysis of the laser's performance requirements for the specific applications of high-precision laser processing is an important aspect for further development of the technique. We have predicted and experimentally verified that maximal edge roughness of single-micrometer-sized features was below 200 nm, including the laser's energy and positioning stability, beam deflection, the effect of spot spacing, and efficient isolation of mechanical vibrations. We have demonstrated that a novel fiber laser operating regime in bursts of pulses increases the laser energy stability. The results of our research improve the potential of fiber laser sources for material processing applications and facilitate their use through enabling the operation at lower pulse energies in bursts as opposed to single pulse regimes.

Thermal and Optical Modulation of the Carrier Mobility in OTFTs Based on an Azo-anthracene Liquid Crystal Organic Semiconductor.

PubMed

Chen, Yantong; Li, Chao; Xu, Xiuru; Liu, Ming; He, Yaowu; Murtaza, Imran; Zhang, Dongwei; Yao, Chao; Wang, Yongfeng; Meng, Hong

2017-03-01

One of the most striking features of organic semiconductors compared with their corresponding inorganic counterparts is their molecular diversity. The major challenge in organic semiconductor material technology is creating molecular structural motifs to develop multifunctional materials in order to achieve the desired functionalities yet to optimize the specific device performance. Azo-compounds, because of their special photoresponsive property, have attracted extensive interest in photonic and optoelectronic applications; if incorporated wisely in the organic semiconductor groups, they can be innovatively utilized in advanced smart electronic applications, where thermal and photo modulation is applied to tune the electronic properties. On the basis of this aspiration, a novel azo-functionalized liquid crystal semiconductor material, (E)-1-(4-(anthracen-2-yl)phenyl)-2-(4-(decyloxy)phenyl)diazene (APDPD), is designed and synthesized for application in organic thin-film transistors (OTFTs). The UV-vis spectra of APDPD exhibit reversible photoisomerizaton upon photoexcitation, and the thin films of APDPD show a long-range orientational order based on its liquid crystal phase. The performance of OTFTs based on this material as well as the effects of thermal treatment and UV-irradiation on mobility are investigated. The molecular structure, stability of the material, and morphology of the thin films are characterized by thermal gravimetric analysis (TGA), polarizing optical microscopy (POM), (differential scanning calorimetry (DSC), UV-vis spectroscopy, atomic force microscopy (AFM), and scanning tunneling microscopy (STM). This study reveals that our new material has the potential to be applied in optical sensors, memories, logic circuits, and functional switches.

Bionanocomposites materials for food packaging applications: Concepts and future outlook.

PubMed

Youssef, Ahmed M; El-Sayed, Samah M

2018-08-01

Bionanocomposites materials open a chance for the usage of novel, high performance, lightweight, and ecofriendly composite materials making them take place the traditional non-biodegradable plastic packaging materials. Biopolymers like polysaccharides such as chitosan (CS), carboxymethyl cellulose (CMC), starch and cellophane could be used to resolve environmental hazards owing to their biodegradability and non-toxicity. In addition these advantages, polysaccharides have some disadvantages for example poor mechanical properties and low resistance to water. Therefore, nanomaterials are used to improve the thermal, mechanical and gas barrier properties without hindering their biodegradable and non-toxic characters. Furthermore, the most favorable nanomaterials are layered silicate nanoclays for example montmorillonite (MMT) and kaolinite, zinc oxide (ZnO-NPs), titanium dioxide (TiO 2 -NPs), and silver nanoparticles (Ag-NPs). In packaging application, the improvement of barrier properties of prepared films against oxygen, carbon dioxide, flavor compounds diffusion through the packaging films. Wide varieties of nanomaterials are suitable to offer smart and/or intelligent properties for food packaging materials, as demonstrated by oxygen scavenging capability, antimicrobial activity, and sign of the level of exposure to various harmful features for instance oxygen levels or insufficient temperatures. The compatibility between nanomaterials and polymers matrix consider the most challenge for the preparation of bionanocomposites as well as getting whole distribution of nanoparticles into the polymer matrix. We keen in this review the development of packaging materials performance and their mechanical, degradability and thermal stability as well as antibacterial activity for utilization of bionanocomposites in different packaging application is considered. Copyright © 2018 Elsevier Ltd. All rights reserved.

Use of silicon carbide sludge to form porous alkali-activated materials for insulating application

NASA Astrophysics Data System (ADS)

Prud'homme, E.; Joussein, E.; Rossignol, S.

2015-07-01

One of the objectives in the field of alkali-activated materials is the development of materials having greater thermal performances than conventional construction materials such as aerated concrete. The aim of this paper is to present the possibility to obtain controlled porosity and controlled thermal properties with geopolymer materials including a waste like silicon carbide sludge. The porosity is created by the reaction of free silicon contains in silicon carbide sludge leading to the formation of hydrogen. Two possible ways are investigated to control the porosity: modification of mixture formulation and additives introduction. The first way is the most promising and allowed the formation of materials presenting the same density but various porosities, which shows that the material is adaptable to the application. The insulation properties are logically linked to the porosity and density of materials. A lower value of thermal conductivity of 0.075 W.m-1.K-1 can be reached for a material with a low density of 0.27 g.cm-3. These characteristics are really good for a mineral-based material which always displays non-negligible resistance to manipulation.

Immediate performance of self-etching versus system adhesives with multiple light-activated restoratives.

PubMed

Irie, M; Suzuki, K; Watts, D C

2004-11-01

The purpose of this study was to evaluate the performance of both single and double applications of (Adper Prompt L-Pop) self-etching dental adhesive, when used with three classes of light-activated restorative materials, in comparison to the performance of each restorative system adhesive. Evaluation parameters to be considered for the adhesive systems were (a) immediate marginal adaptation (or gap formation) in tooth cavities, (b) free setting shrinkage-strain determined by the immediate marginal gap-width in a non-bonding Teflon cavity, and (c) their immediate shear bond-strengths to enamel and to dentin. The maximum marginal gap-width and the opposing-width (if any) in the tooth cavities and in the Teflon cavities were measured immediately (3 min) after light-activation. The shear bond-strengths to enamel and to dentin were also measured at 3 min. For light-activated restorative materials during early setting (<3 min), application of Adper Prompt L-Pop exhibited generally superior marginal adaptation to most system adhesives. But there was no additional benefit from double application. The marginal-gaps in tooth cavities and the marginal-gaps in Teflon cavities were highly correlated (r = 0.86-0.89, p < 0.02-0.01). For enamel and dentin shear bond-strengths, there were no significant differences between single and double applications, for all materials tested except Toughwell and Z 250 with enamel. Single application of a self-etch adhesive was a feasible and beneficial alternative to system adhesives for several classes of restorative. Marginal gap-widths in tooth cavities correlated more strongly with free shrinkage-strain magnitudes than with bond-strengths to tooth structure.

Advantages and Challenges of Relaxor-PbTiO3 Ferroelectric Crystals for Electroacoustic Transducers- A Review

PubMed Central

Zhang, Shujun; Li, Fei; Jiang, Xiaoning; Kim, Jinwook; Luo, Jun; Geng, Xuecang

2014-01-01

Relaxor-PbTiO3 (PT) based ferroelectric crystals with the perovskite structure have been investigated over the last few decades due to their ultrahigh piezoelectric coefficients (d33 > 1500 pC/N) and electromechanical coupling factors (k33 > 90%), far outperforming state-of-the-art ferroelectric polycrystalline Pb(Zr,Ti)O3 ceramics, and are at the forefront of advanced electroacoustic applications. In this review, the performance merits of relaxor-PT crystals in various electroacoustic devices are presented from a piezoelectric material viewpoint. Opportunities come from not only the ultrahigh properties, specifically coupling and piezoelectric coefficients, but through novel vibration modes and crystallographic/domain engineering. Figure of merits (FOMs) of crystals with various compositions and phases were established for various applications, including medical ultrasonic transducers, underwater transducers, acoustic sensors and tweezers. For each device application, recent developments in relaxor-PT ferroelectric crystals were surveyed and compared with state-of-the-art polycrystalline piezoelectrics, with an emphasis on their strong anisotropic features and crystallographic uniqueness, including engineered domain - property relationships. This review starts with an introduction on electroacoustic transducers and the history of piezoelectric materials. The development of the high performance relaxor-PT single crystals, with a focus on their uniqueness in transducer applications, is then discussed. In the third part, various FOMs of piezoelectric materials for a wide range of ultrasound applications, including diagnostic ultrasound, therapeutic ultrasound, underwater acoustic and passive sensors, tactile sensors and acoustic tweezers, are evaluated to provide a thorough understanding of the materials’ behavior under operational conditions. Structure-property-performance relationships are then established. Finally, the impacts and challenges of relaxor-PT crystals are summarized to guide on-going and future research in the development of relaxor-PT crystals for the next generation electroacoustic transducers. PMID:25530641

Method of producing a hybrid matrix fiber composite

DOEpatents

Deteresa, Steven J [Livermore, CA; Lyon, Richard E [Absecon, NJ; Groves, Scott E [Brentwood, CA

2006-03-28

Hybrid matrix fiber composites having enhanced compressive performance as well as enhanced stiffness, toughness and durability suitable for compression-critical applications. The methods for producing the fiber composites using matrix hybridization. The hybrid matrix fiber composites comprised of two chemically or physically bonded matrix materials, whereas the first matrix materials are used to impregnate multi-filament fibers formed into ribbons and the second matrix material is placed around and between the fiber ribbons that are impregnated with the first matrix material and both matrix materials are cured and solidified.

Study of reflection gratings recorded in polyvinyl alcohol/acrylamide-based photopolymer.

PubMed

Fuentes, Rosa; Fernández, Elena; García, Celia; Beléndez, Augusto; Pascual, Inmaculada

2009-12-01

High-spatial-frequency fringes associated with reflection holographic optical elements are difficult to obtain with currently available recording materials. In this work, holographic reflection gratings were stored in a polyvinyl alcohol/acrylamide photopolymer. This material is formed of acrylamide photopolymer, which is considered interesting material for optical storage applications such as holographic memories. The experimental procedure for examining the high-spatial-frequency response of this material is explained, and the experimental results obtained are presented. With the aim of obtaining the best results, the performance of different material compositions is compared.

High capacity hydrogen storage materials: attributes for automotive applications and techniques for materials discovery.

PubMed

Yang, Jun; Sudik, Andrea; Wolverton, Christopher; Siegel, Donald J

2010-02-01

Widespread adoption of hydrogen as a vehicular fuel depends critically upon the ability to store hydrogen on-board at high volumetric and gravimetric densities, as well as on the ability to extract/insert it at sufficiently rapid rates. As current storage methods based on physical means--high-pressure gas or (cryogenic) liquefaction--are unlikely to satisfy targets for performance and cost, a global research effort focusing on the development of chemical means for storing hydrogen in condensed phases has recently emerged. At present, no known material exhibits a combination of properties that would enable high-volume automotive applications. Thus new materials with improved performance, or new approaches to the synthesis and/or processing of existing materials, are highly desirable. In this critical review we provide a practical introduction to the field of hydrogen storage materials research, with an emphasis on (i) the properties necessary for a viable storage material, (ii) the computational and experimental techniques commonly employed in determining these attributes, and (iii) the classes of materials being pursued as candidate storage compounds. Starting from the general requirements of a fuel cell vehicle, we summarize how these requirements translate into desired characteristics for the hydrogen storage material. Key amongst these are: (a) high gravimetric and volumetric hydrogen density, (b) thermodynamics that allow for reversible hydrogen uptake/release under near-ambient conditions, and (c) fast reaction kinetics. To further illustrate these attributes, the four major classes of candidate storage materials--conventional metal hydrides, chemical hydrides, complex hydrides, and sorbent systems--are introduced and their respective performance and prospects for improvement in each of these areas is discussed. Finally, we review the most valuable experimental and computational techniques for determining these attributes, highlighting how an approach that couples computational modeling with experiments can significantly accelerate the discovery of novel storage materials (155 references).

The Influence of Intrinsic Framework Flexibility on Adsorption in Nanoporous Materials

DOE PAGES

Witman, Matthew; Ling, Sanliang; Jawahery, Sudi; ...

2017-03-30

For applications of metal–organic frameworks (MOFs) such as gas storage and separation, flexibility is often seen as a parameter that can tune material performance. In this work we aim to determine the optimal flexibility for the shape selective separation of similarly sized molecules (e.g., Xe/Kr mixtures). To obtain systematic insight into how the flexibility impacts this type of separation, we develop a simple analytical model that predicts a material’s Henry regime adsorption and selectivity as a function of flexibility. We elucidate the complex dependence of selectivity on a framework’s intrinsic flexibility whereby performance is either improved or reduced with increasingmore » flexibility, depending on the material’s pore size characteristics. However, the selectivity of a material with the pore size and chemistry that already maximizes selectivity in the rigid approximation is continuously diminished with increasing flexibility, demonstrating that the globally optimal separation exists within an entirely rigid pore. Molecular simulations show that our simple model predicts performance trends that are observed when screening the adsorption behavior of flexible MOFs. These flexible simulations provide better agreement with experimental adsorption data in a high-performance material that is not captured when modeling this framework as rigid, an approximation typically made in high-throughput screening studies. We conclude that, for shape selective adsorption applications, the globally optimal material will have the optimal pore size/chemistry and minimal intrinsic flexibility even though other nonoptimal materials’ selectivity can actually be improved by flexibility. In conclusion, equally important, we find that flexible simulations can be critical for correctly modeling adsorption in these types of systems.« less

Supramolecule-Inspired Fabrication of Carbon Nanoparticles In Situ Anchored Graphene Nanosheets Material for High-Performance Supercapacitors.

PubMed

Huang, Yulan; Gao, Aimei; Song, Xiaona; Shu, Dong; Yi, Fenyun; Zhong, Jie; Zeng, Ronghua; Zhao, Shixu; Meng, Tao

2016-10-12

The remarkable electrochemical performance of graphene-based materials has drawn a tremendous amount of attention for their application in supercapacitors. Inspired by supramolecular chemistry, the supramolecular hydrogel is prepared by linking β-cyclodextrin to graphene oxide (GO). The carbon nanoparticles-anchored graphene nanosheets are then assembled after the hydrothermal reduction and carbonization of the supramolecular hydrogels; here, the β-cyclodextrin is carbonized to carbon nanoparticles that are uniformly anchored on the graphene nanosheets. Transmission electron microscopy reveals that carbon nanoparticles with several nanometers are uniformly anchored on both sides of graphene nanosheets, and X-ray diffraction spectra demonstrate that the interlayer spacing of graphene is enlarged due to the anchored nanoparticles among the graphene nanosheets. The as-prepared carbon nanoparticles-anchored graphene nanosheets material (C/r-GO-1:3) possesses a high specific capacitance (310.8 F g -1 , 0.5 A g -1 ), superior rate capability (242.5 F g -1 , 10 A g -1 ), and excellent cycle stability (almost 100% after 10 000 cycles, at the scan rate of 50 mV s -1 ). The outstanding electrochemical performance of the resulting C/r-GO-1:3 is mainly attributed to (i) the presence of the carbon nanoparticles, (ii) the enlarged interlayer spacing of the graphene sheets, and (iii) the accelerated ion transport rates toward the interior of the electrode material. The supramolecule-inspired approach for the synthesis of high-performance carbon nanoparticles-modified graphene sheets material is promising for future application in graphene-based energy storage devices.

The Influence of Intrinsic Framework Flexibility on Adsorption in Nanoporous Materials

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

Witman, Matthew; Ling, Sanliang; Jawahery, Sudi

For applications of metal–organic frameworks (MOFs) such as gas storage and separation, flexibility is often seen as a parameter that can tune material performance. In this work we aim to determine the optimal flexibility for the shape selective separation of similarly sized molecules (e.g., Xe/Kr mixtures). To obtain systematic insight into how the flexibility impacts this type of separation, we develop a simple analytical model that predicts a material’s Henry regime adsorption and selectivity as a function of flexibility. We elucidate the complex dependence of selectivity on a framework’s intrinsic flexibility whereby performance is either improved or reduced with increasingmore » flexibility, depending on the material’s pore size characteristics. However, the selectivity of a material with the pore size and chemistry that already maximizes selectivity in the rigid approximation is continuously diminished with increasing flexibility, demonstrating that the globally optimal separation exists within an entirely rigid pore. Molecular simulations show that our simple model predicts performance trends that are observed when screening the adsorption behavior of flexible MOFs. These flexible simulations provide better agreement with experimental adsorption data in a high-performance material that is not captured when modeling this framework as rigid, an approximation typically made in high-throughput screening studies. We conclude that, for shape selective adsorption applications, the globally optimal material will have the optimal pore size/chemistry and minimal intrinsic flexibility even though other nonoptimal materials’ selectivity can actually be improved by flexibility. In conclusion, equally important, we find that flexible simulations can be critical for correctly modeling adsorption in these types of systems.« less

Composite Structural Materials

NASA Technical Reports Server (NTRS)

Ansell, G. S.; Loewy, R. G.; Wiberly, S. E.

1984-01-01

The development and application of filamentary composite materials, is considered. Such interest is based on the possibility of using relatively brittle materials with high modulus, high strength, but low density in composites with good durability and high tolerance to damage. Fiber reinforced composite materials of this kind offer substantially improved performance and potentially lower costs for aerospace hardware. Much progress has been made since the initial developments in the mid 1960's. There were only limited applied to the primary structure of operational vehicles, mainly as aircrafts.

Advanced Ablative Insulators and Methods of Making Them

NASA Technical Reports Server (NTRS)

Congdon, William M.

2005-01-01

Advanced ablative (more specifically, charring) materials that provide temporary protection against high temperatures, and advanced methods of designing and manufacturing insulators based on these materials, are undergoing development. These materials and methods were conceived in an effort to replace the traditional thermal-protection systems (TPSs) of re-entry spacecraft with robust, lightweight, better-performing TPSs that can be designed and manufactured more rapidly and at lower cost. These materials and methods could also be used to make improved TPSs for general aerospace, military, and industrial applications.

Computational Materials: Modeling and Simulation of Nanostructured Materials and Systems

NASA Technical Reports Server (NTRS)

Gates, Thomas S.; Hinkley, Jeffrey A.

2003-01-01

The paper provides details on the structure and implementation of the Computational Materials program at the NASA Langley Research Center. Examples are given that illustrate the suggested approaches to predicting the behavior and influencing the design of nanostructured materials such as high-performance polymers, composites, and nanotube-reinforced polymers. Primary simulation and measurement methods applicable to multi-scale modeling are outlined. Key challenges including verification and validation of models are highlighted and discussed within the context of NASA's broad mission objectives.

Critical Role of Monoclinic Polarization Rotation in High-Performance Perovskite Piezoelectric Materials.

PubMed

Liu, Hui; Chen, Jun; Fan, Longlong; Ren, Yang; Pan, Zhao; Lalitha, K V; Rödel, Jürgen; Xing, Xianran

2017-07-07

High-performance piezoelectric materials constantly attract interest for both technological applications and fundamental research. The understanding of the origin of the high-performance piezoelectric property remains a challenge mainly due to the lack of direct experimental evidence. We perform in situ high-energy x-ray diffraction combined with 2D geometry scattering technology to reveal the underlying mechanism for the perovskite-type lead-based high-performance piezoelectric materials. The direct structural evidence reveals that the electric-field-driven continuous polarization rotation within the monoclinic plane plays a critical role to achieve the giant piezoelectric response. An intrinsic relationship between the crystal structure and piezoelectric performance in perovskite ferroelectrics has been established: A strong tendency of electric-field-driven polarization rotation generates peak piezoelectric performance and vice versa. Furthermore, the monoclinic M_{A} structure is the key feature to superior piezoelectric properties as compared to other structures such as monoclinic M_{B}, rhombohedral, and tetragonal. A high piezoelectric response originates from intrinsic lattice strain, but little from extrinsic domain switching. The present results will facilitate designing high-performance perovskite piezoelectric materials by enhancing the intrinsic lattice contribution with easy and continuous polarization rotation.